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Shahira Kamal Anis Botros, Nesrine El Gharbawi, Gehan Shahin, Hend Al Lithy, Mahmoud El Sherbiny
Egyptian Journal of Medical Human Genetics, Volume 22, pp 1-10; doi:10.1186/s43042-021-00145-0

Background It has been postulated that the interaction between environmental risk factors and genetic susceptibility is a possible cause for the development of acute myeloid leukemia (AML). Cytochrome P450 (CYP) detoxification enzymes are responsible for the elimination of oxidative stress. Genetic polymorphisms in these enzymes may cause AML due to enhanced accumulation of reactive oxygen species. To study the association between CYP3A4 (A290G) and CYP2B6 (G516T) gene polymorphisms and the predisposition and prognosis of AML, 50 upfront AML patients and 50 healthy individuals were genotyped for CYP2B6 (G516T) and CYP3A4 (A290G) single-nucleotide polymorphisms (SNPs) using polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) technique. The polymorphisms were evaluated in relation to the response to chemotherapy and survival. Results CYP2B6 gene mutation carries a threefold risk of developing AML (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.3–6.9), whereas CYP3A4 gene mutation carries approximately fourfold risk (OR, 3.8; 95% CI, 1.4–10.1). The presence of combined gene mutation conferred about 15-fold increased risk of developing AML compared with the presence of a single gene mutation (OR, 14.8; 95% CI, 1.8–124.2). CYP3A4 gene mutation is associated with worse overall survival (P = 0.030). Conclusion CYP enzyme gene polymorphisms are associated with the development of AML. Elimination of oxidative stress in genetically susceptible individuals may decrease the risk of AML and may improve survival.
, Ariel Nisenbaum
Fixed Point Theory and Algorithms for Sciences and Engineering, Volume 2021, pp 1-21; doi:10.1186/s13663-021-00694-4

String-averaging is an algorithmic structure used when handling a family of operators in situations where the algorithm in hand requires to employ the operators in a specific order. Sequential orderings are well known, and a simultaneous order means that all operators are used simultaneously (in parallel). String-averaging allows to use strings of indices, constructed by subsets of the index set of all operators, to apply the operators along these strings, and then to combine their end-points in some agreed manner to yield the next iterate of the algorithm. String-averaging methods were discussed and used for solving the common fixed point problem or its important special case of the convex feasibility problem. In this paper we propose and investigate string-averaging methods for the problem of best approximation to the common fixed point set of a family of operators. This problem involves finding a point in the common fixed point set of a family of operators that is closest to a given point, called an anchor point, in contrast with the common fixed point problem that seeks any point in the common fixed point set. We construct string-averaging methods for solving the best approximation problem to the common fixed points set of either finite or infinite families of firmly nonexpansive operators in a real Hilbert space. We show that the simultaneous Halpern–Lions–Wittman–Bauschke algorithm, the Halpern–Wittman algorithm, and the Combettes algorithm, which were not labeled as string-averaging methods, are actually special cases of these methods. Some of our string-averaging methods are labeled as “static” because they use a fixed pre-determined set of strings. Others are labeled as “quasi-dynamic” because they allow the choices of strings to vary, between iterations, in a specific manner and belong to a finite fixed pre-determined set of applicable strings. For the problem of best approximation to the common fixed point set of a family of operators, the full dynamic case that would allow strings to unconditionally vary between iterations remains unsolved, although it exists and is validated in the literature for the convex feasibility problem where it is called “dynamic string-averaging”.
Yuanli Chen, Hui Fan, Xinlin Zha, Wenwen Wang, Yi Wu, Yi Xiong, Kun Yan, Yuedan Wang, Dong Wang
Fashion and Textiles, Volume 8, pp 1-12; doi:10.1186/s40691-021-00252-x

High efficiency and anti-pollution oil/water separation membrane has been widely explored and researched. There are a large number of hydroxyl groups on the surface of silica, which has good wettability and can be used for oil-water separation membranes. Hydrophilic silica nanostructures with different morphologies were synthesized by changing templates and contents of trimethylbenzene (TMB). Here, silica nanospheres with radical pores, hollow silica nanospheres and worm-like silica nanotubes were separately sprayed on the PVA-co-PE nanofiber membrane (PM). The abundance of hydroxyl groups and porous structures on PM surfaces enabled the absorption of silica nanospheres through hydrogen bonds. Compared with different silica nanostructures, it was found that the silica/PM exhibited excellent super-hydrophilicity in air and underwater “oil-hating” properties. The PM was mass-produced in our lab through melt-extrusion-phase-separation technique. Therefore, the obtained membranes not only have excellent underwater superoleophobicity but also have a low-cost production. The prepared silica/PM composites were used to separate n-hexane/water, silicone oil/water and peanut oil water mixtures via filtration. As a result, they all exhibited efficient separation of oil/water mixture through gravity-driven filtration.
Goki Kamei, Shigeki Ishibashi, Koki Yoshioka, Satoru Sakurai, Hiroyuki Inoue, Masakazu Ishikawa, Yu Mochizuki, Nobuo Adachi
Arthroplasty, Volume 3, pp 1-6; doi:10.1186/s42836-021-00072-w

Background In total knee arthroplasty (TKA) using the modified gap technique, the soft-tissue balance is measured after osteotomy of the distal femur and proximal tibia (conventional bone gap). However, after osteotomy, the flexion gap size during 90° knee flexion may be larger than that observed after implantation. The tension of the lateral compartment during 90° flexion may also be reduced after osteotomy of the distal femur. We manufactured a distal femoral trial component to reproduce the condition after implantation and prior to posterior condyle osteotomy. This study aimed to evaluate the effect of the trial component on the flexion gap. Methods This prospective study included 21 consecutive patients aged 78 years with medial osteoarthritis who underwent cruciate-retaining TKA between February 2017 and March 2018. The postoperative flexion gap size and inclination during 90° flexion were compared between cases with and without the trial component. Results The mean joint gap size with the trial component (13.4 ± 0.80 mm) was significantly smaller than that without the trial component (14.7 ± 0.84 mm). The mean gap inclination angle with the trial component (3.7° ± 0.62°) was significantly smaller than that without the trial component (5.5° ± 0.78°). Conclusions In the present study, the joint gap size and medial tension were significantly reduced after the trial component had been set. Accurate measurement of the soft-tissue balance is an important factor in the modified gap technique, and this method using a distal femoral trial component can offer better outcomes than those achieved with conventional methods.
Hyeong-Wook Jo, Min-Kyu Park, Hyo-Min Heo, Hwang-Ju Jeon, Sung-Deuk Choi, Sung-Eun Lee, Joon-Kwan Moon
Applied Biological Chemistry, Volume 64, pp 1-12; doi:10.1186/s13765-021-00602-9

Mycotoxins are secondary metabolites produced by various fungi and are known to have a significant negative impact on human and animal health. When feedstuffs are contaminated with mycotoxins, their toxicities may be caused a variety of diseases. In this study, the residual mycotoxins in feedstuffs were analyzed using LC–MS/MS incorporated with QuEChERS extraction. Analytical method validation was performed for LOD, LOQ, linearity, and recoveries with consideration of matrix effects prior to the residual analysis. They were all reached to the accepted range of validation level. Using 39 feedstuff samples (5 g) for mycotoxin analysis, nine samples were contaminated by four major mycotoxins such as fumonisin B1 (FB1), deoxynivalenol, fumonisin B2, and zearalenone. Among them, FB1 was detected at the highest concentration as 18.0943 mg/kg. The total sum of fumonisins in 39 samples did not exceed the maximum residual level (MRL) criterion set by Korean Food and Drug Administration. Altogether, intensive management of mycotoxins in Korean feedstuffs should be implemented with proper and routine monitoring, even their residual concentrations are not exceeded over the MRL levels because of high frequent detection found in this study.
G. Fabiola Safonte, , Pietro Columba
Agricultural and Food Economics, Volume 9, pp 1-20; doi:10.1186/s40100-021-00180-w

The purpose of this paper is to analyze how the commoning heritage processes find application for the production of agro-environmental public goods in contexts of high socio-economic marginality and environmental vulnerability, characterized by abandonment and from the consumption of agricultural land for food use. The purpose is to understand how these processes are able to influence, at local level, the governance processes for the implementation of environmental protection strategies. The survey made it possible to verify how the commoning processes aimed at the production of agro-environmental goods generate territorial resilience, understood as a community competence able to structure specific forms of social learning based on priorities identified and defined by the communities. The followed theoretical framework and the methodological approach have allowed on the one hand to draw up a taxonomy of the different territorial dynamics and on the other to identify a mixed indicator system, applicable and replicable also in other contexts, able to describe its dimensions analytically. The assessment of the cognitive elements related to the territorial fabric carried out through the proposed approach has allowed to demonstrate how the knowledge of the territorial capital contributes to the activation of forms of collective intelligence necessary for decision-making processes.
Wanke Liu, Mingkui Wu, , , Wei Ke, Zhiqin Zhu
Satellite Navigation, Volume 2, pp 1-17; doi:10.1186/s43020-021-00038-y

The BeiDou global navigation satellite system (BDS-3) constellation deployment has been completed on June 23, 2020, with a full constellation comprising 30 satellites. In this study, we present the performance assessment of single-epoch Real-Time Kinematic (RTK) positioning with tightly combined BeiDou regional navigation satellite system (BDS-2) and BDS-3. We first investigate whether code and phase Differential Inter-System Biases (DISBs) exist between the legacy B1I/B3I signals of BDS-3/BDS-2. It is discovered that the DISBs are in fact about zero for the baselines with the same or different receiver types at their endpoints. These results imply that BDS-3 and BDS-2 are fully interoperable and can be regarded as one constellation without additional DISBs when the legacy B1I/B3I signals are used for precise relative positioning. Then we preliminarily evaluate the single-epoch short baseline RTK performance of tightly combined BDS-2 and the newly completed BDS-3. The performance is evaluated through ambiguity resolution success rate, ambiguity dilution of precision, as well as positioning accuracy in kinematic and static modes using the datasets collected in Wuhan. Experimental results demonstrate that the current BDS-3 only solutions can deliver comparable ambiguity resolution performance and much better positioning accuracy with respect to BDS-2 only solutions. Moreover, the RTK performance is much improved with tightly combined BDS-3/BDS-2, particularly in challenging or harsh conditions. The single-frequency single-epoch tightly combined BDS-3/BDS-2 solution could deliver an ambiguity resolution success rate of 96.9% even with an elevation cut-off angle of 40°, indicating that the tightly combined BDS-3/BDS-2 could achieve superior RTK positioning performance in the Asia–Pacific region. Meanwhile, the three-dimensional (East/North/Up) positioning accuracy of BDS-3 only solution (0.52 cm/0.39 cm/2.14 cm) in the kinematic test is significantly better than that of the BDS-2 only solution (0.85 cm/1.02 cm/3.01 cm) due to the better geometry of the current BDS-3 constellation. The tightly combined BDS-3/BDS-2 solution can provide the positioning accuracy of 0.52 cm, 0.22 cm, and 1.80 cm, respectively.
, Svetlana A. Romanenko, Yulia V. Maksimova, Asia R. Shorina, Dmitry V. Yudkin
Egyptian Journal of Medical Human Genetics, Volume 22, pp 1-4; doi:10.1186/s43042-021-00146-z

Background The presence of small supernumerary marker chromosomes (sSMCs) in a karyotype leads to diagnostic questions because the resulting extra material may cause abnormal development depending on the origin of the duplication/triplication. Because SMCs are so small, their origin cannot be determined by conventional cytogenetic techniques, and new molecular cytogenetic methods are necessary. Here, we applied a target approach to chromosome rearrangement analysis by isolating a chromosome of interest via microdissection and using it in fluorescence in situ hybridization (FISH) as a probe in combination with whole-chromosome painting probes. This approach allows to identify origins of both the euchromatin and repeat-rich regions of a marker. Case presentation We report a case of an adult male with congenital atresia of the rectum and anus, anotia, and atresia of the external auditory canal along with hearing loss. Karyotyping and FISH analysis with whole-chromosome painting probes of acrocentric chromosomes and the constructed microdissection library of the marker chromosome reliably identified an additional chromosome in some metaphases: mos 47,XY,+idic(22)(q11.2)[14]/46,XY [23]. Conclusion We propose to use whole-chromosome libraries and microdissected chromosomes in FISH to identify SMCs enriched with repeated sequences. We show that the methodology is successful in identifying the composition of a satellited marker chromosome.
Karunesh Chand, Ravi Patcharu, Badal Parikh, Arun Kumar Yadav
Annals of Pediatric Surgery, Volume 17, pp 1-7; doi:10.1186/s43159-021-00076-w

Background Intussusception is the one of the commonest causes of intestinal obstruction requiring urgent attention in early childhood. There is no gold standard of non-operative reduction. We report our 6 years’ experience in non-operative reduction using our “RIGHT” (Reduction of Intussusception under General anesthesia using Hydrostatic Technique) technique, emphasizing the need to perform the procedure in the operating room (OR) under general anesthesia. This prospective observational study covering the period from July 2014 till May 2020 included patients diagnosed with intussusception. Hydrostatic reduction was performed in the OR under general anesthesia by infusing a saline enema and the reduction was confirmed by ultrasound. Results Forty-eight patients underwent reduction using the RIGHT technique. Successful reduction was achieved in 44 (91.6%) patients. Four (8.3%) patients needed surgery, three (6.2%) due to failed reduction and one (2.0%) due to perforation. One (2.2%) patient developed a recurrence. Conclusions The “RIGHT” technique is a combination of the best available techniques of reduction of intussusception. It ensures patient safety by being performed in the OR, being pain free, avoiding radiation, avoiding the risk of aspiration associated with sedation, and also being able to immediately address a failure of reduction or a complication by surgical exploration.
Marwa A. Saad, Reham A. Aboelwafa, Eman H. Elsayed
Egyptian Rheumatology and Rehabilitation, Volume 48, pp 1-10; doi:10.1186/s43166-021-00069-y

Background Osteoporosis is a major health problem of elders. Dual X-ray absorptiometry (DEXA) is the commonly used modality for diagnosis osteoporosis; serum markers have been suggested for predicting osteoporosis and discriminate osteoporotic from healthy subjects. We aimed to analyze the status of some bone turnover biochemical markers namely PINP, B-ALP, estrogen, and progesterone in the elderly osteoporotic and osteopenic women as probable markers for the discrimination between patients and healthy individual in diagnosing osteoporosis, and also, to detect the impact of osteoporosis on quality of life of patients using assessment of the quality of life for osteoporosis (ECOS-16). Post-menopausal 108 females were involved in the current study, divided into two groups (osteoporotic group (60 with BMD˂-2.5), osteopenic group (48 with BMD between − 1 and − 2.5)), and 60 healthy elderly females as control group were involved in the study. Serum levels of procollagen type I N-terminal propeptide (PINP), bone alkaline phosphatase (B-ALP), estrogen, and progesterone were measured by ELISA technique. Results PINP and B-ALP significantly differ between studied groups. Also, PINP and B-ALP levels had high sensitivity and specificity to discriminate osteoporotic patients from healthy individuals. PINP and B-ALP significantly correlated with bone mineral density (BMD) and with ECOS-16. Estrogen differs significantly between osteoporotic and osteopenic groups and significantly correlated with bone mineral density of femur (BMD-F) and bone mineral density of spine (BMD-S) in the osteopenic group. Progesterone differed significantly between patients and controls and significantly correlated with BMD-F in the osteoporotic group. Conclusion We can consider PINP and B-ALP as biomarkers for early detection then monitoring of osteoporosis. Measuring these serum markers can replace the assessment of BMD if not available. Also, it could replace the gap between BMD subsequently spaced assessment or could be of value in cases with severe spondylosis, DISH syndrome, old spondylarthritis, and/or previous spinal surgery. Sex hormones could not differentiate the normal from the osteoporotic/osteopenic patients, so they cannot be used as diagnostic or prognostic markers. Validation of this assumption needs large and longitudinal studies.
P. Scollo, M. Ferrara, B. Pecorino, A. B. Di Stefano, G. Scibilia
Gynecological Surgery, Volume 18, pp 1-6; doi:10.1186/s10397-021-01085-8

Background Vulvar cancer is a rare gynecological malignancy that primarily affects women of postmenopausal age. Treatment is mainly surgical, particularly for vulvar squamous cell carcinoma, the most prevalent histotype. In patients with unifocal tumors with a maximum diameter of <4 cm, in the absence of suspected inguinal lymph nodes, sentinel lymph node (SLN) biopsy is recommended. The use of a radioactive tracer is mandatory; the use of the vital blue dye is optional. Results Two patients diagnosed with vulvar squamous cell carcinoma (FIGO IB stage) underwent bilateral radical vulvectomy, SLN search and removal, and bilateral inguinal lymphadenectomy at the Cannizzaro Hospital Operative Unit of Obstetrics and Gynecology Department (Catania, Italy). Three milliliters of indocyanine green (ICG) 0.5 mg/mL was administered in 3 peritumoral injections under general anesthesia to screen the SLN. The images were acquired using an intraoperative infrared camera system, which allowed intraoperative visualization of the SLN. An SLN was identified for each patient. The lymph nodes examined by the pathologist were negative for metastatic localization of the disease. However, patients underwent bilateral inguinofemoral lymphadenectomy, as this procedure is not currently codified as a gold standard for the detection of SLN in vulvar cancer. All the lymph nodes removed were negative for the localization of vulvar carcinoma metastases. Conclusions The potential of the administration of indocyanine green (ICG) allows the execution of SLN biopsy, avoiding the multiple administrations of radiocolloid in the pre-operative phase, painful for the patient, elimination, and exposure to radioactivity. Therefore, while requiring standardization of the methodology and a large-scale application, this procedure could open a new surgical management perspective in patients with early-stage vulvar cancer.
, Sabiha Armin, Aurelio Vargas, Victoria M. Chu, Kristen Fain, Jessica Nelson
Middle East Current Psychiatry, Volume 28, pp 1-7; doi:10.1186/s43045-021-00097-6

Background Schizophrenia is a disorder that affects about 1% of the US population, with an extensive impact on patients’ health and their risk of later developing comorbidities from treatment. While literature on the side effect profile of antipsychotics is abundant, there are few studies on identification of anticholinergic effects on gut motility and prophylaxis development. The aim of this review is to consider antipsychotic-associated constipation in patients with schizophrenia and to discuss management of antipsychotic-induced constipation as documented in the literature. Main body We present a case of antipsychotic-induced constipation and conducted a literature review assessing the prevalence of this issue in this population. The search was done on Embase, MEDLINE, Cochrane Library, and PubMed databases. Key word searches included constipation with concurrent antipsychotic use, antipsychotics and anticholinergic effects, factors causing constipation in schizophrenia, social disparities involved with constipation, and colorectal cancer screenings. Main findings included high complication rates that may be explained by clozapine-specific side effects, negative health habits, disease, and treatment-related metabolic disorders. Co-existing negative symptoms could also be associated with health outcomes and was found to have adverse consequences on schizophrenia progression. Comorbidities of diabetes and cardiovascular complications contributed to gut hypomotility. Caregiver burden was a factor in delayed recognition of constipation as a side effect. Routine surveillance for symptoms and optimization of medications facilitates early recognition of constipation. Conclusion Overall, there is insufficient trial-based evidence to compare the effectiveness and safety of common pharmacological interventions for constipation, such as lactulose, polyethylene glycol, stool softeners, and lubricant laxatives.
May Abdellatif, Ismail Mohamed Elhawary, Marwa Mohamed Mahmoud, Eman R. Youness, Walaa Alsharany Abuelhamd
Egyptian Pediatric Association Gazette, Volume 69, pp 1-7; doi:10.1186/s43054-021-00059-x

Background A few published data on maternal and cord levels of zinc and copper with conflicting results were reported. We aimed to measure zinc and copper levels in the maternal blood and cord blood of newborns and correlate their levels with the gestational age and anthropometric measurements. This cross-sectional study included 75 full-term and preterm neonates and their mothers. These neonates were divided into 2 groups according to their gestational age. Serum levels of copper and zinc were estimated for the mothers of the studied neonates as well as their cord samples. This was done using atomic absorption spectrophotometry. Results The mean cord serum zinc in full term was 0.88 ± 0.18 μg/ml whereas in preterms was 0.73 ± 0.13 μg/ml. The mean cord copper in full term was 1.37 ± 0.26 μg/ml, whereas in preterms was 0.75 ± 0.28 μg/ml. Comparison between cord zinc and copper levels and maternal levels were statistically significant (p < 0.001). A significant positive correlation was found between zinc levels in neonates and their mothers (r 0.644; p < 0.000) and a similar positive correlation was found between copper levels in neonates and their mothers (r 0.625; p 0.000). A highly significant positive correlation was found between cord zinc and copper and anthropometric measurements. Conclusion The present work draws our attention to the significant correlation between trace elements in pregnant mothers and fetal development. Also, prematurity adversely influences zinc and copper levels in neonates.
, Randolph R. Singh, Lubomira Kovalova, Oliver Jaeggi, Todor Kondić,
Environmental Sciences Europe, Volume 33, pp 1-21; doi:10.1186/s12302-021-00475-1

Background Applying non-target analysis (NTA) in regulatory environmental monitoring remains challenging—instead of having exploratory questions, regulators usually already have specific questions related to environmental protection aims. Additionally, data analysis can seem overwhelming because of the large data volumes and many steps required. This work aimed to establish an open in silico workflow to identify environmental chemical unknowns via retrospective NTA within the scope of a pre-existing Swiss environmental monitoring campaign focusing on industrial chemicals. The research question addressed immediate regulatory priorities: identify pollutants with industrial point sources occurring at the highest intensities over two time points. Samples from 22 wastewater treatment plants obtained in 2018 and measured using liquid chromatography–high resolution mass spectrometry were retrospectively analysed by (i) performing peak-picking to identify masses of interest; (ii) prescreening and quality-controlling spectra, and (iii) tentatively identifying priority “known unknown” pollutants by leveraging environmentally relevant chemical information provided by Swiss, Swedish, EU-wide, and American regulators. This regulator-supplied information was incorporated into MetFrag, an in silico identification tool replete with “post-relaunch” features used here. This study’s unique regulatory context posed challenges in data quality and volume that were directly addressed with the prescreening, quality control, and identification workflow developed. Results One confirmed and 21 tentative identifications were achieved, suggesting the presence of compounds as diverse as manufacturing reagents, adhesives, pesticides, and pharmaceuticals in the samples. More importantly, an in-depth interpretation of the results in the context of environmental regulation and actionable next steps are discussed. The prescreening and quality control workflow is openly accessible within the R package Shinyscreen, and adaptable to any (retrospective) analysis requiring automated quality control of mass spectra and non-target identification, with potential applications in environmental and metabolomics analyses. Conclusions NTA in regulatory monitoring is critical for environmental protection, but bottlenecks in data analysis and results interpretation remain. The prescreening and quality control workflow, and interpretation work performed here are crucial steps towards scaling up NTA for environmental monitoring.
Ebu Bekir Aygar,
International Journal of Geo-Engineering, Volume 12, pp 1-26; doi:10.1186/s40703-021-00142-7

Due to the increasing population and resulting transportation needs, the number of subway and high-speed railway projects has also increased. The geometric constraints of such projects have caused many tunnels to be built in weak ground. Thus, weak ground tunnelling has attracted the attention of tunnel engineers and researchers. The main purposes of this study are to analyse the T4 tunnel excavated in weak ground and to compare the results obtained from the analytical solutions and 3D numerical analyses. This study specifically considers the T4 tunnel support system used in the Ankara İzmir High Speed Railway Project (Afyonkarahisar-Banaz Section). The T4 tunnel route encounters weak ground composed of layers of extremely weak mudstone, clayey sand, weakly cemented sandstone, and silty–clay matrix with pebbles. The tunnel overburden ranges from 10 to 35 m, which is shallow. After the excavation work of the T4 tunnel, severe deformation and critical stability problems in the shallow part (where the overburden is approximately 10 m) were encountered inside the tunnel, leading to a halt in construction. This was followed by revisions to the tunnel support system, leading to successful completion of the tunnel excavation. Numerical simulations of the low overburden section are performed using the commercially available FLAC3D program that uses the finite difference method. The characteristics of insufficient/ineffective support systems and adequate support systems for shallow tunnels excavated through weak ground are discussed in this study. Additionally, problems that pertain to the tunnel itself and its support system are discussed. The results of the 3D numerical analyses and analytical solutions are compared, and the advantages of 3D numerical analyses are discussed. The importance and necessity of tunnel face stability and roof stability for tunnel stability in weak ground is illustrated. Consequently, solutions based on analytical and numerical analyses are presented, and the analysis methodology and solutions proposed in the study can help guide weak ground tunnelling design and evaluation.
Avian Research, Volume 12, pp 1-4; doi:10.1186/s40657-021-00248-7

The study of seed dispersal, biotic seed dispersal, and even less, the role of birds in it, have been almost neglected in deserts. Virtually absent from the literature on seed dispersal are the ground-jays, genus Podoces, four species of the crow family that inhabit arid environments, even true deserts, from Iran to Mongolia. Although they are omnivorous, they seem to mainly depend on the seeds of desert plants during the cold season. There are suggestions in sparse literature that they may contribute to seed dispersal similarly to several corvid species of other climates, by caching seeds in useful microsites to save them for later consumption and thus actually favoring the germination of the seeds they fail to recover. Future research might benefit from comparison with the vast literature on their better-known seed-caching relatives. This paper is aimed at providing basic information on each ground-jay species and some suggestions for investigating their likely symbiosis with desert plants, with possible applications to the maintenance and restoration of vegetation in a very extended arid zone.
Yiqiang Dai, Jianzhong Zhou, Lixia Wang, Mingsheng Dong,
Food Production, Processing and Nutrition, Volume 3, pp 1-11; doi:10.1186/s43014-021-00054-0

Soy whey, a liquid nutritional by-product of soybean manufacture, is rich in proteins, oligosaccharides and isoflavones. Soy whey can be used to produce functional beverages, instead of discarding it as a waste. In this study, unfermented soy whey (USW) and Cordyceps militaris SN-18-fermented soy whey (FSW) were investigated and compared for their physicochemical and functional properties by high performance liquid chromatography (HPLC) and DNA damage assay. Results show that C. militaris SN-18 fermentation could increase the contents of essential amino acids, total phenolic and flavonoid and isoflavone aglycones and eliminate the oligosaccharides in soy whey. Furthermore, C. militaris SN-18 could significantly enhance the ABTS radical scavenging ability, reducing power and ferric reducing power of soy whey, and its fermented products could prominently attenuate Fenton reaction-induced DNA damage. These findings indicate that soy whey can potentially be converted into a novel soy functional beverage by C. militaris SN-18 fermentation. Graphical abstract
Shuaiqi Meng, Ruipeng An, Zhongyu Li, Ulrich Schwaneberg, Yu Ji, Mehdi D. Davari, Fang Wang, Meng Wang, Meng Qin, Kaili Nie, et al.
Bioresources and Bioprocessing, Volume 8, pp 1-10; doi:10.1186/s40643-021-00379-1

An active site is normally located inside enzymes, hence substrates should go through a tunnel to access the active site. Tunnel engineering is a powerful strategy for refining the catalytic properties of enzymes. Here, P450BsβHI (Q85H/V170I) derived from hydroxylase P450Bsβ from Bacillus subtilis was chosen as the study model, which is reported as a potential decarboxylase. However, this enzyme showed low decarboxylase activity towards long-chain fatty acids. Here, a tunnel engineering campaign was performed for modulating the substrate preference and improving the decarboxylation activity of P450BsβHI. The finally obtained BsβHI-F79A variant had a 15.2-fold improved conversion for palmitic acid; BsβHI-F173V variant had a 3.9-fold improved conversion for pentadecanoic acid. The study demonstrates how the substrate preference can be modulated by tunnel engineering strategy.
, Anthony Purcell
Geoscience Letters, Volume 8, pp 1-19; doi:10.1186/s40562-021-00184-w

Past sea-level change represents the large-scale state of global climate, reflecting the waxing and waning of global ice sheets and the corresponding effect on ocean volume. Recent developments in sampling and analytical methods enable us to more precisely reconstruct past sea-level changes using geological indicators dated by radiometric methods. However, ice-volume changes alone cannot wholly account for these observations of local, relative sea-level change because of various geophysical factors including glacio-hydro-isostatic adjustments (GIA). The mechanisms behind GIA cannot be ignored when reconstructing global ice volume, yet they remain poorly understood within the general sea-level community. In this paper, various geophysical factors affecting sea-level observations are discussed and the details and impacts of these processes on estimates of past ice volumes are introduced.
Cheah Huei Yoong, Venkata Reddy Palleti, Rajib Ranjan Maiti, Arlindo Silva, Christopher M Poskitt
Cybersecurity, Volume 4, pp 1-24; doi:10.1186/s42400-021-00069-7

Cyber-physical systems (CPSs) in critical infrastructure face serious threats of attack, motivating research into a wide variety of defence mechanisms such as those that monitor for violations of invariants, i.e. logical properties over sensor and actuator states that should always be true. Many approaches for identifying invariants attempt to do so automatically, typically using data logs, but these can miss valid system properties if relevant behaviours are not well-represented in the data. Furthermore, as the CPS is already built, resolving any design flaws or weak points identified through this process is costly. In this paper, we propose a systematic method for deriving invariants from an analysis of a CPS design, based on principles of the axiomatic design methodology from design science. Our method iteratively decomposes a high-level CPS design to identify sets of dependent design parameters (i.e. sensors and actuators), allowing for invariants and invariant checkers to be derived in parallel to the implementation of the system. We apply our method to the designs of two CPS testbeds, SWaT and WADI, deriving a suite of invariant checkers that are able to detect a variety of single- and multi-stage attacks without any false positives. Finally, we reflect on the strengths and weaknesses of our approach, how it can be complemented by other defence mechanisms, and how it could help engineers to identify and resolve weak points in a design before the controllers of a CPS are implemented.
Muhammad Noman, , Keyou Wang, Bei Han
Protection and Control of Modern Power Systems, Volume 6, pp 1-18; doi:10.1186/s41601-021-00186-y

Globally abundant wave energy for power generation attracts ever increasing attention. Because of non-linear dynamics and potential uncertainties in ocean energy conversion systems, generation productivity needs to be increased by applying robust control algorithms. This paper focuses on control strategies for a small ocean energy conversion system based on a direct driven permanent magnet synchronous generator (PMSG). It evaluates the performance of two kinds of control strategies, i.e., traditional field-oriented control (FOC) and robust adaptive control. The proposed adaptive control successfully achieves maximum velocity and stable power production, with reduced speed tracking error and system response time. The adaptive control also guarantees global system stability and its superiority over FOC by using a non-linear back-stepping control technique offering a better optimization solution. The robustness of the ocean energy conversion system is further enhanced by investigating the Lyapunov method and the use of a DC-DC boost converter. To overcome system complexity, turbine-generator based power take-off (PTO) is considered. A Matlab/Simulink study verifies the advantages of a non-linear control strategy for an Oscillating Water Column (OWC) based power generation system.
V. Ponnuvel Sakthivel, P. Duraisamy Sathya
Protection and Control of Modern Power Systems, Volume 6, pp 1-13; doi:10.1186/s41601-021-00188-w

Multi-Area Multi-Fuel Economic Dispatch (MAMFED) aims to allocate the best generation schedule in each area and to offer the best power transfers between different areas by minimizing the objective functions among the available fuel alternatives for each unit while satisfying various constraints in power systems. In this paper, a Fuzzified Squirrel Search Algorithm (FSSA) algorithm is proposed to solve the single-area multi-fuel economic dispatch (SAMFED) and MAMFED problems. Squirrel Search Algorithm (SSA) mimics the foraging behavior of squirrels based on the dynamic jumping and gliding strategies. In the SSA approach, predator presence behavior and a seasonal monitoring condition are employed to increase the search ability of the algorithm, and to balance the exploitation and exploration. The suggested approach considers the line losses, valve point loading impacts, multi-fuel alternatives, and tie-line limits of the power system. Because of the contradicting nature of fuel cost and pollutant emission objectives, weighted sum approach and price penalty factor are used to transfer the bi-objective function into a single objective function. Furthermore, a fuzzy decision strategy is introduced to find one of the Pareto optimal fronts as the best compromised solution. The feasibility of the FSSA is tested on a three-area test system for both the SAMFED and MAMFED problems. The results of FSSA approach are compared with other heuristic approaches in the literature. Multi-objective performance indicators such as generational distance, spacing metric and ratio of non-dominated individuals are evaluated to validate the effectiveness of FSSA. The results divulge that the FSSA is a promising approach to solve the SAMFED and MAMFED problems while providing a better compromise solution in comparison with other heuristic approaches.
Yoojin Chong, Hye Lim Lee, Jihyeon Song, Youngshim Lee, Bong-Gyu Kim, Hyejung Mok, Joong-Hoon Ahn
Applied Biological Chemistry, Volume 64, pp 1-10; doi:10.1186/s13765-021-00607-4

Resveratrol is a typical plant phenolic compound whose derivatives are synthesized through hydroxylation, O-methylation, prenylation, and oligomerization. Resveratrol and its derivatives exhibit anti-neurodegenerative, anti-rheumatoid, and anti-inflammatory effects. Owing to the diverse biological activities of these compounds and their importance in human health, this study attempted to synthesize five resveratrol derivatives (isorhapontigenin, pterostilbene, 4-methoxyresveratrol, piceatannol, and rhapontigenin) using Escherichia coli. Two-culture system was used to improve the final yield of resveratrol derivatives. Resveratrol was synthesized in the first E. coli cell that harbored genes for resveratrol biosynthesis including TAL (tyrosine ammonia lyase), 4CL (4-coumaroyl CoA ligase), STS (stilbene synthase) and genes for tyrosine biosynthesis such as aroG (deoxyphosphoheptonate aldolase) and tyrA (prephenate dehydrogenase). Thereafter, culture filtrate from the first cell was used for the modification reaction carried out using the second E. coli harboring hydroxylase and/or O-methyltransferase. Approximately, 89.8 mg/L of resveratrol was synthesized and using the same, five derivatives were prepared with a conversion rate of 88.2% to 22.9%. Using these synthesized resveratrol derivatives, we evaluated their anti-inflammatory activity. 4-Methoxyresveratrol, pterostilbene and isorhapontigenin showed the anti-inflammatory effects without any toxicity. In addition, pterostilbene exhibited the enhanced anti-inflammatory effects for macrophages compared to resveratrol.
Diana Sachmpazidi, Alice Olmstead, Amreen Nasim Thompson, Charles Henderson, Andrea Beach
International Journal of STEM Education, Volume 8, pp 1-23; doi:10.1186/s40594-021-00273-4

Background Team-based instructional change is a promising model for improving undergraduate STEM instruction. Teams are more likely to produce sustainable, innovative, and high-quality outcomes than individuals working alone. However, teams also tend to involve higher risks of failure and can result in inefficient allocation of valuable resources. At this point, there is limited knowledge of how teams in the context of STEM higher education should work to achieve desirable outcomes. Results In this study, we collect semi-structured interview data from 23 team members from a total of 4 teams at 3 institutions across the USA. We analyze the results using a grounded theory approach and connect them to the existing literature. This study builds upon the first part of our work that developed a model of team inputs that lead to team outcomes. In this part, we identify the mechanisms by which input characteristics influence teamwork and outcomes. Team member data expand this initial model by identifying key aspects of team processes and emergent states. In this paper, we present five team processes: strategic leadership, egalitarian power dynamics, team member commitment, effective communication, and clear decision-making processes, that shape how teams work together, and three emergent states: shared vision, psychological safety, and team cohesion, that team members perceived as important aspects of how teams feel and think when working together. Conclusions This work furthers our understanding of how instructional change teams can be successful. However, due to the highly complex nature of teams, further investigation with more teams is required to test and enrich the emerging theory.
Yaqin Wang, Xinyue Zhang, Tao Hu,
Phytopathology Research, Volume 3, pp 1-6; doi:10.1186/s42483-021-00085-y

Malvastrum coromandelianum is a common weed plant frequently found around agricultural fields. Three virus isolates (Y249, Y278 and Y281) were obtained from M. coromandelianum with yellow vein symptoms in Honghe and Baoshan, Yunnan Province, China. Specific 500 bp products were amplified from total DNA extracts using universal primers for members of the genus Begomovirus. The complete viral genome sequences of both Y278 and Y281 were determined to be 2743 nucleotides, and that of Y249 was determined to be 2740 nucleotides. Sequence alignments and phylogenetic analyses support the proposal of creating new species in the genus Begomovirus, for which the name malvastrum yellow vein Baoshan virus (MaYVBsV) is proposed for Y278 and Y281, and malvastrum yellow vein Honghe virus (MaYVHhV) is proposed for Y249.
S. M. Iqbal S. Zainal, , Raizal S. M. Rashid
International Journal of Concrete Structures and Materials, Volume 15, pp 1-28; doi:10.1186/s40069-021-00457-w

The knee beam–column joint is a critical location in a Reinforced Concrete (RC) structure particularly when subjected to earthquake vibrations. The current structural design codes dictate the use of high amounts of steel reinforcements in the frame joint to manage large strain demands in seismic-prone regions. However, these codes could result in the congestion of steel reinforcements in the limited joint area which can consequently produce numerous construction complications. This study aims to improve the structural performance of Knee Joint (KJ) by reducing the load induced to the embedded steel reinforcements during seismic vibrations. Hence, this study attempted to develop a Hybrid Fiber Reinforced Concrete (HyFRC) by combining multiple synthetic fibers to be introduced onto KJ. Six KJ specimens were cast using five developed HyFRC materials and one Control specimen to be experimentally tested under lateral cyclic loading. The results indicated significant improvements for the HyFRC KJ specimens particularly in energy dissipation capacity, stiffness degradation rate, displacement ductility toughness, steel reinforcement strain and hysteretic behavior. A total of six Finite Element (FE) KJ models were developed using the HyFRC materials to verify the results from the experimental testing. The accuracy of the proposed FE models resulted in average percentage differences of 25.89% for peak load, 3.45% for peak load displacement and 0.18% for maximum displacements from the experimental data. In conclusion, this study developed HyFRC materials that are beneficial in providing cost-efficient alternatives to Reinforced Concrete (RC) KJ structures in areas with low to moderate level of seismic risks.
Erin Scanlon, Zachary W. Taylor, John Raible, Jacob Bates,
International Journal of STEM Education, Volume 8, pp 1-16; doi:10.1186/s40594-021-00282-3

Background While there have been numerous calls to increase the participation of people with disabilities in STEM, many postsecondary institutions are not equipped to support students with disabilities. We examined the accessibility of 139 webpages from 73 postsecondary institutions in the USA that contained information about the undergraduate physics curriculum and graduate research programs. We selected these webpages as they are common entry points for students interested in pursuing a physics degree. We used Tenon and Mac OS X’s VoiceOver software to assess the level of accessibility of these webpages as measured by alignment with the Web Content Accessibility Guidelines (WCAG) 2.0. Results We found that only one webpage had minimal accessibility errors (i.e., 10 errors), while the other webpages had numerous accessibility errors. Five specific error types accounted for the majority of all errors. The five most common errors were related to information, structure, and relationships of content (1.3.1 Level A; 39.7%); text alternatives for non-text content (1.1.1 Level A; 27.0%); information about link purpose (2.4.4 Level A; 14.7%); capability to resize text (1.4.4 Level AA; 10.0%); and information about the name, role, and value of user interface components (4.1.2 Level A; 11.2%). Conclusions We present and describe the five common accessibility errors we identified in the webpages in our sample, suggest solutions for these errors, and provide implications for students with disabilities, instructors and staff, institutional administration, and the broader physics community.
, Ryoichiro Agata, Tsuyoshi Ichimura, Kohei Fujita, Takuma Yamaguchi, Takeshi Iinuma
Earth, Planets and Space, Volume 73, pp 1-3; doi:10.1186/s40623-021-01404-5

An amendment to this paper has been published and can be accessed via the original article.
C. Stolle, N. Olsen, B. Anderson, E. Doornbos, A. Kuvshinov
Earth, Planets and Space, Volume 73, pp 1-4; doi:10.1186/s40623-021-01409-0

Bing He, Yong Hong, Zhen Li
Journal of Inequalities and Applications, Volume 2021, pp 1-12; doi:10.1186/s13660-021-02593-z

For the Hilbert type multiple integral inequality $$ \int _{\mathbb{R}_{+}^{n}} \int _{\mathbb{R}_{+}^{m}} K\bigl( \Vert x \Vert _{m,\rho }, \Vert y \Vert _{n, \rho }\bigr) f(x)g(y) \,\mathrm{d} x \,\mathrm{d} y \leq M \Vert f \Vert _{p, \alpha } \Vert g \Vert _{q, \beta } $$ ∫ R + n ∫ R + m K ( ∥ x ∥ m , ρ , ∥ y ∥ n , ρ ) f ( x ) g ( y ) d x d y ≤ M ∥ f ∥ p , α ∥ g ∥ q , β with a nonhomogeneous kernel $K(\|x\|_{m, \rho }, \|y\|_{n, \rho })=G(\|x\|^{\lambda _{1}}_{m, \rho }/ \|y\|^{\lambda _{2}}_{n, \rho })$ K ( ∥ x ∥ m , ρ , ∥ y ∥ n , ρ ) = G ( ∥ x ∥ m , ρ λ 1 / ∥ y ∥ n , ρ λ 2 ) ( $\lambda _{1}\lambda _{2}> 0$ λ 1 λ 2 > 0 ), in this paper, by using the weight function method, necessary and sufficient conditions that parameters p, q, $\lambda _{1}$ λ 1 , $\lambda _{2}$ λ 2 , α, β, m, and n should satisfy to make the inequality hold for some constant M are established, and the expression formula of the best constant factor is also obtained. Finally, their applications in operator boundedness and operator norm are also considered, and the norms of several integral operators are discussed.
Li-Fan Peng
Middle East Fertility Society Journal, Volume 26, pp 1-5; doi:10.1186/s43043-021-00056-5

Background With the growth of women’s age, ovarian failure can be caused by various factors. For the women who need chemotherapy because of cancer factors, the preservation of fertility is more urgent. The treatment of cancer is also a process in which all tissues and organs of the body are severely damaged, especially in the reproductive system. Main body As a new fertility preservation technology, autologous ovarian tissue cryopreservation and transplantation is developing rapidly and showing great potentiality in preserving ovarian endocrine function of young cervical cancer patients. Vitrification and slow freezing are two common techniques applied for ovarian tissue cryopreservation. Thus, cryopreserved/thawed ovarian tissue and transplantation act as an important method to preserve ovarian function during radiotherapy and chemotherapy, and ovarian cryopreservation by vitrification is a very effective and extensively used method to cryopreserve ovaries. The morphology of oocytes and granulosa cells and the structure of organelles were observed under the microscope of histology; the hormone content in the stratified culture medium of granulosa cells with the diameter of follicle was used to evaluate the development potential of ovarian tissue, and finally the ovarian tissue stimulation was determined by the technique of ovarian tissue transplantation. Conclusions Although there are some limitations, the team members still carry out this review to provide some references and suggestions for clinical decision-making and further clinical research.
Mariana Vallejo, Rachel Cordeiro, Paulo A. N. Dias, Carla Moura, , Inês J. Seabra, Cândida Maria Malça,
Bioresources and Bioprocessing, Volume 8, pp 1-12; doi:10.1186/s40643-021-00377-3

Considering the expected increasing demand for cellulose fibers in the near future and that its major source is wood pulp, alternative sources such as vegetable wastes from agricultural activities and agro-food industries are currently being sought to prevent deforestation. In the present study, cellulose was successfully isolated from six agroindustrial residues: corncob, corn husk, grape stalk, pomegranate peel, marc of strawberry-tree fruit and fava pod. Cellulose fibers were characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, stereomicroscopy and scanning electron microscopy (SEM). Despite the evident morphological differences among the extracted celluloses, results revealed similar compositional and thermal properties with the wood-derived commercial microcrystalline cellulose used as a control. Trace amounts of lignin or hemicellulose were detected in all cellulose samples, with the exception of corncob cellulose, that exhibited the greatest extraction yield (26%) and morphological similarities to wood-derived microcrystalline cellulose, visible through SEM. Furthermore, corncob cellulose was found to have thermal properties (TOnset of 307.17 °C, TD of 330.31 °C, and ΔH of 306.04 kJ/kg) suitable for biomedical applications.
Weiting Chen, Xuemeng Bai, Tengfei Xu, Shanshan Ke, Kailai Deng, Haiqing Xie
Advances in Bridge Engineering, Volume 2, pp 1-16; doi:10.1186/s43251-020-00031-6

This paper proposes a novel twin-column pier with a steel shear link (SSL) installed in the cap beam to reduce seismic damage in the transverse direction. The SSL interrupts the rigid cap beam and relieves the coupled deformation of the two columns. Benefits of the yieldable SSL in the event of a strong earthquake are the longer effective deformation of a column and limited axial compressive load. A benchmark reinforced-concrete bridge is employed in a seismic performance evaluation to verify the damage reduction performance of the novel twin-column pier with an SSL. Five numerical models, calibrated in a physical component test, are built in ABAQUS; that is, one original bridge and four novel bridges with different SSLs and accompanying configurations. Modal analysis shows that introducing the SSL does not change the overall structural dynamic characteristics. The nonlinear dynamic analysis results indicate that adopting the SSL effectively reduces the peak compressive strain of the reinforced-concrete column, but energy dissipation from the SSL is negligible compared with the total inputted seismic energy. There is no evident change in the macro seismic response of the twin-column pier when using the SSL, such as overall drift and structural damping ratio. Moreover, a transverse continuous main girder is suggested for realizing an additional restoring moment at the column top, which further reduces compressive strain.
Alistair Becker, Michael B. Lowry, Matthew D. Taylor
Animal Biotelemetry, Volume 9, pp 1-9; doi:10.1186/s40317-021-00236-0

Background Water current data can be a useful predictor variable to include in acoustic telemetry studies given its link to changes in fish behaviour. While there are a range of sensors which can measure currents, they are often expensive and logistically difficult to deploy and maintain. Contemporary acoustic receivers measure tilt angle which may act as a proxy for water current data if the receiver is moored on a rope and buoy system and allowed to sway in the direction of water flow. We tested the relationship between tilt angle and water current by co-locating two types of commonly deployed receivers with current meters. Results Both receivers (Vemco VR4 and VR2AR) displayed similar ranges in tilt angle. While the VR4 could only measure tilt on a daily basis, the VR2AR measurements were taken hourly; these data were then also aggregated on a daily scale. A positive relationship was found between the tilt angle for both types of receivers and current speed, including for both aggregated daily and hourly data for the VR2AR. Both receivers tended to slightly over-estimate current at lower speeds and underestimate it at high speeds. Conclusions These data show tilt angles recorded by commonly deployed receivers could be incorporated as a proxy for current flow where dedicated current loggers are absent. We would recommend programming receivers to record tilt as frequently as possible to account for short-term variability in environmental conditions.
Gurmehar Kaur Grewal, Neelam Joshi, Yadhu Suneja
Egyptian Journal of Biological Pest Control, Volume 31, pp 1-7; doi:10.1186/s41938-021-00407-4

Background Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) is a serious agricultural pest that infests many commercially important crops of Southeast Asian countries. Indiscriminate use of chemical pesticides has led to various health hazards as well as insecticide resistance. Entomopathogenic fungi (EPF) provide an important alternative as biological control agents. Metarhizium rileyi is an EPF with a specific host range for lepidopteran pests. The present study aimed to identify virulent M. rileyi isolate against S. litura larvae and analyse their extracellular cuticle-degrading enzyme activities. Results Three M. rileyi isolates viz M. rileyi NIPHM, M. rileyi MTCC 4254 and M. rileyi MTCC 10395 formulations were evaluated at different concentrations against 2nd instar larvae of S. litura. A maximum percent mortality of 63.33% was recorded in M. rileyi NIPHM (12 g/l), followed by M. rileyi MTCC 4254 (58.33%) at the same concentration, 10 days post-treatment. Maximum means of chitinase, protease and lipase activities (0.44, 1.58 and 2.95 U/ml, respectively) were recorded in the case of M. rileyi NIPHM. Correlation analysis was positive between enzyme activity and larval mortality. Conclusions Metarhizium rileyi NIPHM recorded the highest enzymatic activity and exhibited the maximum mortality rate against 2nd instar larvae of S. litura, suggesting the possible role of these enzymes in the pathogenicity of the fungus. Further knowledge in this regard may help in the development of enzyme-based screening methods for selecting virulent fungal isolates for the eco-friendly management of crop pests.
Financial Innovation
Financial Innovation, Volume 7, pp 1-4; doi:10.1186/s40854-021-00241-5

An amendment to this paper has been published and can be accessed via the original article.
Financial Innovation, Volume 7, pp 1-37; doi:10.1186/s40854-021-00239-z

Exposure to market risk is a core objective of the Capital Asset Pricing Model (CAPM) with a focus on systematic risk. However, traditional OLS Beta model estimations (Ordinary Least Squares) are plagued with several statistical issues. Moreover, the CAPM considers only one source of risk and supposes that investors only engage in similar behaviors. In order to analyze short and long exposures to different sources of risk, we developed a Time–Frequency Multi-Betas Model with ARMA-EGARCH errors (Auto Regressive Moving Average Exponential AutoRegressive Conditional Heteroskedasticity). Our model considers gold, oil, and Fama–French factors as supplementary sources of risk and wavelets decompositions. We used 30 French stocks listed on the CAC40 (Cotations Assistées Continues 40) within a daily period from 2005 to 2015. The conjugation of the wavelet decompositions and the parameters estimates constitutes decision-making support for managers by multiplying the interpretive possibilities. In the short-run, (“Noise Trader” and “High-Frequency Trader”) only a few equities are insensitive to Oil and Gold fluctuations, and the estimated Market Betas parameters are scant different compared to the Model without wavelets. Oppositely, in the long-run, (fundamentalists investors), Oil and Gold affect all stocks but their impact varies according to the Beta (sensitivity to the market). We also observed significant differences between parameters estimated with and without wavelets.
Akash Roy, Sunil Taneja, Arka De, Ashim Das, Ajay K. Duseja, Virendra Singh
Egyptian Liver Journal, Volume 11, pp 1-4; doi:10.1186/s43066-021-00083-x

Background Acute liver failure (ALF) is a syndromic diagnosis, consisting of jaundice, coagulopathy, and any degree of encephalopathy in a patient without pre-existing liver disease within 26 weeks of the onset of symptoms. Autoimmune hepatitis has a wide range of presentations and can rarely present as ALF, which frequently tends to be autoantibody negative. Tropical infections like dengue, malaria, and leptospirosis, which present as mimickers of ALF, always remain a differential diagnosis of ALF and mandate an etiology specific management. In rare cases, such infections themselves act as a trigger for autoimmunity. We report a case of diagnostic crossroads of infection and autoimmunity, presenting as acute liver failure and describe the challenges in management. Case presentation A 25-year-old female presented with a syndromic diagnosis of acute liver failure with possibility of tropical illness-related ALF mimic on account of positive Leptospira serology. After initial improvement, there was a rebound worsening of liver functions which prompted a liver biopsy. Biopsy narrowed the differential to Leptospira-associated hepatitis and severe auto-immune hepatitis. Trial of low dose steroid was given which led to dramatic improvement. Conclusion Tropical infections can present as ALF mimics and can themselves act as triggers for autoimmunity. Distinguishing such cases from de-novo acute severe autoimmune hepatitis is difficult and requires therapeutic brinksmanship. An early trial of steroid is mandated but comes with its own challenges.
Elham Ali R. Alshehri
Middle East Current Psychiatry, Volume 28, pp 1-8; doi:10.1186/s43045-021-00096-7

Background Well-being includes the physical, social, and emotional dimensions of a person’s state. University students experience increased levels of psychological and academic distress, mostly affecting their mental well-being. This study employed a descriptive, correlational, cross-sectional design to assess the level of mental well-being among health sciences students at three health science colleges at King Saud University in Riyadh, Saudi Arabia. Convenience total sampling was used to select 339 female undergraduate students from the three faculties. A questionnaire consisting of two parts—a sociodemographic datasheet and the Arabic version of the Warwick–Edinburgh Mental Well-being Scale (WEMWBS) without modifications to assess individuals’ mental well-being—was distributed, with data collection lasting for one month (February 2019). Results Participants had an average level of mental well-being, with the highest recorded among students from the College of Pharmacy and the lowest recorded among the students from the College of Nursing. The study findings revealed no significant correlations or differences in the mental well-being of the questionnaire respondents according to sociodemographic variables. Conclusions It is important to assess the mental well-being of students to detect any possible mental illnesses or disturbances and address any issues so as to support their academic achievement.
Congrong Li, Jinling Song, Jindi Wang
Forest Ecosystems, Volume 8, pp 1-19; doi:10.1186/s40663-021-00300-4

Background Determining the spatial distribution of tree heights at the regional area scale is significant when performing forest above-ground biomass estimates in forest resource management research. The geometric-optical mutual shadowing (GOMS) model can be used to invert the forest canopy structural parameters at the regional scale. However, this method can obtain only the ratios among the horizontal canopy diameter (CD), tree height, clear height, and vertical CD. In this paper, we used a semi-variance model to calculate the CD using high spatial resolution images and expanded this method to the regional scale. We then combined the CD results with the forest canopy structural parameter inversion results from the GOMS model to calculate tree heights at the regional scale. Results The semi-variance model can be used to calculate the CD at the regional scale that closely matches (mainly with in a range from − 1 to 1 m) the CD derived from the canopy height model (CHM) data. The difference between tree heights calculated by the GOMS model and the tree heights derived from the CHM data was small, with a root mean square error (RMSE) of 1.96 for a 500-m area with high fractional vegetation cover (FVC) (i.e., forest area coverage index values greater than 0.8). Both the inaccuracy of the tree height derived from the CHM data and the unmatched spatial resolution of different datasets will influence the accuracy of the inverted tree height. And the error caused by the unmatched spatial resolution is small in dense forest. Conclusions The semi-variance model can be used to calculate the CD at the regional scale, together with the canopy structure parameters inverted by the GOMS model, the mean tree height at the regional scale can be obtained. Our study provides a new approach for calculating tree height and provides further directions for the application of the GOMS model.
Benjamin Maas
European Transport Research Review, Volume 13, pp 1-15; doi:10.1186/s12544-021-00478-2

The past years brought massive changes in the transport and mobility market, accompanied by the rise of concepts such as Mobility as a Service. An enormous increase in publications on this topic documents the growing importance of multimodal mobility solutions for daily transport, but practical applications of the concept are rare. In addition to challenges in the organization of players, this is due to an unclear conception of the service offer and which particular services should be included to what extent. This paper presents the results of an empirical study in the city of Dresden, Germany, where participants could choose out of various bundles of mobility services in a conjoint analysis. The survey provides evidence for the great importance of public transport for the evaluation of mobility bundles as well as for the benefit-enhancing effect of car and bike sharing. A comparison among different user groups reveals a very homogeneous picture of mobility plans, which, however, only partly reflects actual behaviour.
Magda Silva, Isabel S. Pinho, José A. Covas, Natália M. Alves,
Functional Composite Materials, Volume 2, pp 1-21; doi:10.1186/s42252-021-00020-6

Additive manufacturing techniques established a new paradigm in the manufacture of composite materials providing a simple solution to build complex, custom designed shapes. In the biomedical field, 3D printing enabled the production of scaffolds with patient-specific requirements, controlling product architecture and microstructure, and have been proposed to regenerate a variety of tissues such as bone, cartilage, or the nervous system. Polymers reinforced with graphene or graphene derivatives have demonstrated potential interest for applications that require electrical and mechanical properties as well as enhanced cell response, presenting increasing interest for applications in the biomedical field. The present review focuses on graphene-based polymer nanocomposites developed for additive manufacturing fabrication, provides an overview of the manufacturing techniques available to reach the different biomedical applications, and summarizes relevant results obtained with 3D printed graphene/polymer scaffolds and biosensors.
Ghzl Ghazi Alenezi,
Middle East Fertility Society Journal, Volume 26, pp 1-8; doi:10.1186/s43043-021-00053-8

Background Evaluation of awareness and use of family planning methods is important to improve services and policies. This study aimed to assess awareness and use of family planning methods among women in an urban community in the north of Saudi Arabia. A cross-sectional study was carried out in a maternity hospital and 12 primary health care (PHC) centers in Hail City between December 1st, 2019, and May 30, 2020. Results Four hundred married sexually active women aged 18–49 years were interviewed using a pretested structured questionnaire. The mean age of the participant was 32.0±7.5 years, 73.5% were university educated, and 58% were housewives. More than two-thirds of them (67.6%) had ≥3 living children. Most women (85%) ever used, and 66.5% were currently using any method of contraception; however, only one in five who get counseling for the contraceptive method used, and 40% of the last births were unplanned for. Almost all women reported unavailable family planning clinics in their primary healthcare centers. Most participants (83.0%) desired to have >3 children, which indicates that the main purpose of family planning was child spacing rather than limitation. Relying on natural methods as being safer (36.3%), desire to have more children (19%), being afraid from side effects (15.3%), and possibility of difficulty getting pregnant or might cause infertility (13.0%) were reasons the participants viewed for unsung modern contraceptives. Conclusion This study revealed that most women in urban Hail community, northern Saudi Arabia, were aware about and have a positive attitude towards family planning. The majority of the participants ever used, and two-thirds were currently using any contraceptive method/s, which is higher than the national estimate for Saudi Arabia. However, only one in five counseled by healthcare providers for the type of contraceptive method used. Unavailability of family planning services in primary health care centers impedes getting professional counseling. It is imperious to consider family planning clinics to provide quality family planning services.
Feng Xiong,
Advances in Difference Equations, Volume 2021, pp 1-15; doi:10.1186/s13662-021-03350-8

This paper derives several sufficient conditions for the existence of three solutions to the Dirichlet problem for a second-order self-adjoint difference equation involving p-Laplacian through the critical point theory. Furthermore, by using the strong maximum principle, we prove that the three solutions are positive under appropriate assumptions on the nonlinearity. Finally, we present three examples to confirm our results.
Hyunju Kim, Junseo Lee,
Advances in Difference Equations, Volume 2021, pp 1-35; doi:10.1186/s13662-021-03355-3

This article proposes new strategies for solving two-point Fractional order Nonlinear Boundary Value Problems (FNBVPs) with Robin Boundary Conditions (RBCs). In the new numerical schemes, a two-point FNBVP is transformed into a system of Fractional order Initial Value Problems (FIVPs) with unknown Initial Conditions (ICs). To approximate ICs in the system of FIVPs, we develop nonlinear shooting methods based on Newton’s method and Halley’s method using the RBC at the right end point. To deal with FIVPs in a system, we mainly employ High-order Predictor–Corrector Methods (HPCMs) with linear interpolation and quadratic interpolation (Nguyen and Jang in Fract. Calc. Appl. Anal. 20(2):447–476, 2017) into Volterra integral equations which are equivalent to FIVPs. The advantage of the proposed schemes with HPCMs is that even though they are designed for solving two-point FNBVPs, they can handle both linear and nonlinear two-point Fractional order Boundary Value Problems (FBVPs) with RBCs and have uniform convergence rates of HPCMs, $\mathcal{O}(h^{2})$ O ( h 2 ) and $\mathcal{O}(h^{3})$ O ( h 3 ) for shooting techniques with Newton’s method and Halley’s method, respectively. A variety of numerical examples are demonstrated to confirm the effectiveness and performance of the proposed schemes. Also we compare the accuracy and performance of our schemes with another method.
Alireza Hosseini, Mehrdad Shahrani, Shirin Asgharian, Maryam Anjomshoa, Ayoob Rostamzadeh, Zahra Lorigooini, Najmeh Asgharzadeh, Abbas Azari
Future Journal of Pharmaceutical Sciences, Volume 7, pp 1-11; doi:10.1186/s43094-021-00234-2

Background Cyclophosphamide (CP) is an anti-neoplastic alkylating agent that is extensively used in different chemotherapy regimens. Adverse effects on the reproductive system, especially spermatogenesis, are one of the most important side effects of this drug. It is medically essential to use complementary and alternative drugs. Herbal drugs have long been used as a complementary treatment. Our purpose was to study the effect of hydroalcoholic Allium atroviolaceum L. extract on spermatogenesis in CP-treated mice. Results CP affected a significant decrease in sperm count, motility, viability, and morphology. Sperm count was significantly higher in the all extract groups than in the group of control (p<0.001) and CP group (p<0.001, p<0.01). Sperm motility was significantly greater in the extract (100 and 200mg/kg) groups than in the group of control (p<0.05 and <0.001). Sperm immotility and rotational movement were significantly higher in the CP group than in the CP+extract groups (p<0.001). The sperm viability was significantly greater in the CP+extract (200mg/kg) group than in the CP group (p<0.001). The number of headless sperm, sperm with initial tail, with coiled tail, and sperm with curved body, was significantly lower in the CP+extract (200mg/kg) group than in the CP group (p<0.001). Conclusion A. atroviolaceum extract treatment significantly improved CP-induced reproductive toxicity.
Chen Luo, , Dinggui Luo, Lezhang Wei, Yu Liu
Geoscience Letters, Volume 8, pp 1-13; doi:10.1186/s40562-021-00185-9

The Pearl River Delta (PRD) is a densely populated special economic zone in South China where rapid development since the late 1990s coincided with an increase of many environmental problems in recent years. One of these concerns is the high concentration of arsenic (As; up to 300 μg/L in groundwater) that has been documented in the PRD. Likewise, in surface water and soils, As levels are comparatively higher than in other places in China. Arsenic is discharged from various geogenic sources and anthropogenic activities along the river courses before it drains into the Pearl River Estuary. In general, relatively low As concentrations in the river are due to the limited input from weathering of parent rocks. In contrast, where mining is an important industry, As levels in the surroundings are higher, exceeding the national and international standards for drinking water and soil. The presence of sulfide ores and mining operations, such as extraction of heavy metals and disposal of mine tailings, are most likely responsible for the sharp increase of As above background levels in several tributaries draining into the Pearl River. Besides, in the middle and lower reaches of the tributaries, other anthropogenic sources, e.g., industrial effluents and domestic sewage discharge play an important role in increasing As levels. Finally, rice cultivated in the contaminated areas accumulates As and poses a health risk to the local people in the watershed.
Journal of Inequalities and Applications, Volume 2021, pp 1-27; doi:10.1186/s13660-021-02591-1

In this paper, we introduce a new algorithm by incorporating an inertial term with a subgradient extragradient algorithm to solve the equilibrium problems involving a pseudomonotone and Lipschitz-type continuous bifunction in real Hilbert spaces. A weak convergence theorem is well established under certain mild conditions for the bifunction and the control parameters involved. Some of the applications to solve variational inequalities and fixed point problems are considered. Finally, several numerical experiments are performed to demonstrate the numerical efficacy and superiority of the proposed algorithm over other well-known existing algorithms.
, Michael Schukat
Cybersecurity, Volume 4, pp 1-17; doi:10.1186/s42400-021-00080-y

The IEEE 1588 precision time protocol (PTP) is very important for many industrial sectors and applications that require time synchronization accuracy between computers down to microsecond and even nanosecond levels. Nevertheless, PTP and its underlying network infrastructure are vulnerable to cyber-attacks, which can stealthily reduce the time synchronization accuracy to unacceptable and even damage-causing levels for individual clocks or an entire network, leading to financial loss or even physical destruction. Existing security protocol extensions only partially address this problem. This paper provides a comprehensive analysis of strategies for advanced persistent threats to PTP infrastructure, possible attacker locations, and the impact on clock and network synchronization in the presence of security protocol extensions, infrastructure redundancy, and protocol redundancy. It distinguishes between attack strategies and attacker types as described in RFC7384, but further distinguishes between the spoofing and time source attack, the simple internal attack, and the advanced internal attack. Some experiments were conducted to demonstrate the impact of PTP attacks. Our analysis shows that a sophisticated attacker has a range of methodologies to compromise a PTP network. Moreover, all PTP infrastructure components can host an attacker, making the comprehensive protection of a PTP network against a malware infiltration, as for example exercised by Stuxnet, a very tedious task.
Pratap Chandra Pradhan, Rabindra Kumar Sahu, Sidhartha Panda
Journal of Electrical Systems and Information Technology, Volume 8, pp 1-21; doi:10.1186/s43067-021-00033-y

In the current situation, operation and control of power system is a greater challenge. The most significant situation in power system control is load frequency control. In the present work, a hybrid differential evolution and pattern search (hDE-PS) method has been suggested for frequency regulation of electrical power systems. Fractional-order proportional integral derivative (FOPID) controller is implemented for design and analysis purpose. The suggested control method has been applied for two electrical power systems model, i.e., 2-area diverse source power system with/without HVDC linkage and 2-area thermal system. The performances of the suggested controller have been evaluated with PID and optimal controller. The simulation results indicate that system performances are enhanced with the suggested approach for identical structure. Robustness of the suggested approach has been analyzed by variation in random load and the system parameters. The suggested method (hDE-PS tuned FOPID) is further investigated with a 2-area thermal system. The performance of the recommended approach is analyzed by equating the results with other newly available approaches, like Genetic Algorithm (GA), Bacteria Foraging Optimization Algorithm (BFOA), Particle Swarm Optimization (PSO), hybrid BFOA and PSO (hBFOA-PSO), multi-objective Non-dominated Sorting Genetic Algorithm (NSGA)-II and Firefly Algorithm for the similar structure.
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