bluuebunny/crossref_metadata_2025 huggingface dataset:
Escape of SARS-CoV-2 501Y.V2 from neutralization by convalescent plasma
Authors: Cele Sandile , Gazy Inbal , Jackson Laurelle , Hwa Shi-Hsia , Tegally Houriiyah , Lustig Gila , Giandhari Jennifer , Pillay Sureshnee , Wilkinson Eduan , Naidoo Yeshnee , Karim Farina , Ganga Yashica , Khan Khadija , Bernstein Mallory , Balazs Alejandro B. , Gosnell Bernadett I. , Hanekom Willem , Moosa Mahomed-Yunus S. ,   NGS-SA,   COMMIT-KZN Team, Lessells Richard J. , Oliveira Tulio de , Sigal Alex
Published: January 2021

SARS-CoV-2 variants of concern (VOC) have arisen independently at multiple locations and may reduce efficacy of current vaccines targeted at the spike glycoprotein. We re-cently described the emergence of VOC in South Africa (501Y.V2 or PANGO lineage B.1.351) with mutations in the spike receptor-binding domain (RBD) and N-terminal domain (NTD). Here, using a live virus neutralization assay (LVNA), we compared neutralization of a first wave virus (B.1.1.117) versus the 501Y.V2 variant using plasma collected from adults hospitalized with COVID-19 from two South African infection waves, with the second wave dominated by 501Y.V2 infections. Sequencing demonstrated that infections in first wave plasma donors were with viruses harbouring none of the 501Y.V2-defining RBD or NTD mutations, except for one with E484K. 501Y.V2 virus was effectively neutralized by plasma from second wave infections and first wave virus was effectively neutralized by first wave plasma. In cross-neutralization, 501Y.V2 virus was poorly neutralized by first wave plasma, with an 8.4-fold drop in neutralization relative to first wave virus and a 15.1-fold drop relative to 501Y.V2 neutralization by second wave plasma. In contrast, second wave plasma neutralization of first wave virus was more effective, showing 4.1-fold decline relative to 501Y.V2 virus neutralization and 2.3-fold decline relative to first wave plasma neutralization. While we only tested one plasma elicited by E484K alone, this potently neutralized both variants. The observed effective neutralization of first wave virus by 501Y.V2 infection elicited plasma provides preliminary evidence that vaccines based on VOC sequences could retain activity against other circulating SARS-CoV-2 lineages.
The impact of social restrictions during the COVID-19 pandemic on the physical activity levels of older adults: a baseline analysis of the CHARIOT COVID-19 Rapid Response prospective cohort study
Authors: Salman David , Beaney Thomas , Robb Catherine E. , de Jager Loots Celeste A. , Giannakopoulou Parthenia , Udeh-Momoh Chi , Ahmadi-Abhari Sara , Majeed Azeem , Middleton Lefkos T. , McGregor Alison. H.
Published: January 2021

Objectives

Physical inactivity is more common in older adults, is associated with social isolation and loneliness, and contributes to increased morbidity and mortality. We examined the effect of social restrictions, implemented to reduce transmission of COVID-19 in the UK (lockdown), on physical activity (PA) levels of older adults, and the demographic, lifestyle and social predictors of this change.

Design

Baseline analysis of a survey-based prospective cohort study

Setting

Adults enrolled in the Cognitive Health in Ageing Register for Investigational and Observational Trials (CHARIOT) cohort from GP practices in North West London were invited to participate from April to July 2020.

Participants

6,219 cognitively healthy adults aged 50 to 92 years completed the survey.

Main outcome measures

Self-reported PA before and after lockdown, as measured by Metabolic Equivalent of Task (MET) minutes. Associations of PA with demographic, lifestyle and social factors, mood and frailty.

Results

Mean PA was significantly lower following lockdown, from 3,519 MET minutes/week to 3,185 MET minutes/week (p<0.001). After adjustment for confounders and pre-lockdown PA, lower levels of PA after lockdown were found in those who were over 85 years old (640 [95% CI: 246 to 1034] MET minutes/week less); were divorced or single (240 [95% CI: 120 to 360] MET minutes/week less); living alone (277 [95% CI: 152 to 402] MET minutes/week less); reported feeling lonely often (306 [95% CI: 60 to 552] MET minutes/week less); and showed symptoms of depression (1007 [95% CI: 1401 to 612] MET minutes/week less) compared to those aged 50-64 years, married, co-habiting, and not reporting loneliness or depression, respectively.

Conclusions and Implications

Markers of social isolation, loneliness and depression were associated with lower PA following lockdown in the UK. Interventions to improve PA in older adults should take account of social and community factors, and targeted strategies to increase physical activity in socially isolated, lonely and depressed older adults should be considered.
Single-crystal neutron and X-ray diffraction study of garnet-type solid-state electrolyte Li6La3ZrTaO12: an in situ temperature-dependence investigation (2.5 ≤ T ≤ 873 K)
Authors: Redhammer Günther J. , Meven Martin , Ganschow Steffen , Tippelt Gerold , Rettenwander Daniel
Published: January 2021

Large single crystals of garnet-type Li6La3ZrTaO12 (LLZTO) were grown by the Czochralski method and analysed using neutron diffraction between 2.5 and 873 K in order to fully characterize the Li atom distribution, and possible Li ion mobility in this class of potential candidates for solid-state electrolyte battery material. LLZTO retains its cubic symmetry (space group Ia
3
d) over the complete temperature range. When compared to other sites, the octahedral sites behave as the most rigid unit and show the smallest increase in atomic displacement parameters and bond length. The La and Li sites show similar thermal expansion in their bond lengths with temperature, and the anisotropic and equivalent atomic displacement parameters exhibit a distinctly larger increase at temperatures above 400 K. Detailed inspection of nuclear densities at the Li1 site reveal a small but significant displacement from the 24d position to the typical 96h position, which cannot, however, be resolved from the single-crystal X-ray diffraction data. The site occupation of LiI ions on Li1 and Li2 sites remains constant, so there is no change in site occupation with temperature.
Predator‐scale spatial analysis of intra‐patch prey distribution reveals the energetic drivers of rorqual whale super‐group formation
Authors: Cade David E. , Seakamela S. Mduduzi , Findlay Ken P. , Fukunaga Julie , Kahane‐Rapport Shirel R. , Warren Joseph D. , Calambokidis John , Fahlbusch James A. , Friedlaender Ari S. , Hazen Elliott L. , Kotze Deon , McCue Steven , Meÿer Michael , Oestreich William K. , Oudejans Machiel G. , Wilke Christopher , Goldbogen Jeremy A.
Published: January 2021

Animals are distributed relative to the resources they rely upon, often scaling in abundance relative to available resources. Yet, in heterogeneously distributed environments, describing resource availability at relevant spatial scales remains a challenge in ecology, inhibiting understanding of predator distribution and foraging decisions.

We investigated the foraging behaviour of two species of rorqual whales within spatially limited and numerically extraordinary super‐aggregations in two oceans. We additionally described the lognormal distribution of prey data at species‐specific spatial scales that matched the predator's unique lunge‐feeding strategy.

Here we show that both humpback whales off South Africa's west coast and blue whales off the US west coast perform more lunges per unit time within these aggregations than when foraging individually, and that the biomass within gulp‐sized parcels was on average higher and more tightly distributed within super‐group‐associated prey patches, facilitating greater energy intake per feeding event as well as increased feeding rates.

Prey analysis at predator‐specific spatial scales revealed a stronger association of super‐groups with patches containing relatively high geometric mean biomass and low geometric standard deviations than with arithmetic mean biomass, suggesting that the foraging decisions of rorqual whales may be more influenced by the distribution of high‐biomass portions of a patch than total biomass. The hierarchical distribution of prey in spatially restricted, temporally transient, super‐group‐associated patches demonstrated high biomass and less variable distributions that facilitated what are likely near‐minimum intervals between feeding events.

Combining increased biomass with increased foraging rates implied that overall intake rates of whales foraging within super‐groups were approximately double those of whales foraging in other environments. Locating large, high‐quality prey patches via the detection of aggregation hotspots may be an important aspect of rorqual whale foraging, one that may have been suppressed when population sizes were anthropogenically reduced in the 20th century to critical lows.

A free Plain Language Summary can be found within the Supporting Information of this article.
The frequency exponent of artificial sandstone's complex resistivity spectrum
Authors: Jia Jiang , Ke Shizhen , Rezaee Reza , Li Junjian , Wu Feng
Published: January 2021

The complex resistivity spectra of 16 artificial sandstone samples with different physical property at different water and solution saturations were measured and fitted with the Cole–Cole model in the frequency band of 40 Hz to 110 MHz. The frequency exponent in the model indicates the ideal degree of the sample's capacitive property. The experimental result shows that the frequency exponents of the samples are concentrated mainly between 0.82 and 0.88 and present a segmented law that decreases first and then increases with decreasing the water saturation. The minimum frequency exponent has a linear relationship with porosity and cementation index and an exponential relationship with formation factors. The frequency exponent is expected to be used in the study of the oil–water distribution in the reservoir. The frequency exponents of the samples decrease with an increase in clay content. Frequency exponents are independent of the ion type in the solution. Numerical simulation results support that the capacitive property generated by the connected pore‐throat spaces is near ideal, but the capacitive property contributed by the closed pore‐throat spaces is non‐ideal. This could be the possible reason why the frequency exponents of the samples are less than one. The pore‐throats with higher capillary pressure can be blocked and become secondary closed pore‐throat space during the flooding process and result in a decrease in frequency exponent. This can explain the influence of reservoir parameters on frequency exponent and can further clarify the physical significance of the Cole–Cole frequency exponent on the rock's complex resistivity.
Do biochemical parameters and intradialytic symptoms affectpost‐dialysisrecovery time? A prospective, descriptive study
Authors: Ozen Nurten , Cepken Tugba , Tosun Betul
Published: January 2021

The recovery time is defined as the time required to recover from the feelings of lassitude and fatigue. The daily activities of patients are affected by dialysis sessions, requiring significant time for patients to return to their routines. This situation implies a lower quality of life for HD patients. The aim of this study was to investigate the effects of biochemical parameters and intradialytic symptoms on post‐dialysis recovery time in maintenance HD patients. This study was conducted at a private dialysis center during June and August 2019. Data were collected using the “Descriptive Characteristics Form” and the “Dialysis Symptom Index.” “STROBE check‐list” was used for the report of the study. The study was completed with 86 participants. The median post‐dialysis recovery time was 240 min (interquartile range, 120–360 min), and female patients exhibit significantly higher recovery time than male patients. The median BMI was statistically significantly higher in patients whose post‐dialysis recovery time was ≥240 min. Additional findings show that the post‐dialysis recovery time was shortened by 0.230 times for male patients, while intradialytic hypotension (IDH) prolonged the median post‐dialysis recovery time by 3.141 times. Factors underlying the IDH should be determined in order to eradicate the issue. The study was registered inClinicalTrials.govwith the number NCT04274556.
Correlation between vancomycin clearance and cystatin C‐based glomerular filtration rate in paediatric patients
Authors: Oh Yunmi , Park Sojin , Park Esther , Lee Jaehyun , Lee Hukyoung , Kim Jeongmee , Cho Joongbum
Published: January 2021

Aims

Because of limitations with the serum creatinine‐based glomerular filtration rate (GFRcr), estimates of the serum cystatin C‐based glomerular filtration rate (GFRcys) are getting attention to predict vancomycin clearance (CLvan). We evaluated the correlations between (i) CLvan and GFRcr, and (ii) CLvan and GFRcys in paediatric patients.

Methods

We evaluated a retrospective cohort of patients between 1 and 19 years old admitted to a tertiary hospital between 2017 and 2019. CLvan was estimated using measured vancomycin trough concentrations. We conducted Spearman's correlation analyses between CLvan and 1/creatinine, GFRcr, 1/cystatin C and GFRcys. Subgroup analyses were conducted for the young child, child, adolescent subgroups, intensive care unit patients and low body weight (<10th percentile) patients.

Results

We analysed 40 patients. GFRcys correlated with CLvan better than GFRcr did (ρ = 0.731, P < 0.001 vs ρ = 0.504, P = 0.001). In the subgroup analyses, the correlation between GFRcys and CLvan was stronger than that between GFRcr and CLvan (child subgroup ρ = 0.712, P = 0.002 vs ρ = 0.282, P = 0.289; intensive care unit patients ρ = 0.772, P < 0.001 vs ρ = 0.540, P = 0.004; low body weight patients ρ = 0.671, P < 0.001 vs ρ = 0.464, P = 0.022).

Conclusions

Serum cystatin C‐based GFR strongly correlates with vancomycin clearance, suggesting the possibility of better prediction models than creatinine‐based GFR. Further prospective studies are required for the validation of the prediction model in a large paediatric population.
Genetics and Child Development: Recent Advances and Their Implications for Developmental Research
Authors: Armstrong‐Carter Emma , Wertz Jasmin , Domingue Benjamin W.
Published: January 2021

Recent genetic discoveries offer a new lens through which to study cognitive, emotional, behavioral, and social processes that are foundational to children’s development. In this article, we review the latest advances in genomics—genome‐wide association studies and the polygenic scores that have come out of them—and discuss how these techniques can be leveraged to shed light on developmental research questions. Then, we describe how developmental scientists might apply these methods in their own lines of work—for example, in investigations of individual differences in developmental trajectories, intergenerational transmission, peer relationships, and processes of resilience and positive adaptation. Finally, we discuss ethical concerns and limitations of genetics research as they pertain to developmental science.
Immunodeficiency (CVID and CD4 lymphopenia) is associated with a high risk of malignancy among adults with primary immune deficiency
Authors: Shavit R , Maoz-Segal R , Prizinsky S , Haj-Yahia S , Offengenden I , Machnas-Mayan D , Tunisky Y , Iancovici-Kidon M , Agmon-Levin N
Published: January 2021

Primary immunodeficiency disorders (PID) are a group of heterogeneous disorders characterized by recurrent infections, autoimmunity, increased lymphoproliferative disorders and other malignancies. PID is classified into cellular or humoral disorders or a combination of both. We evaluated the clinical differences among adult patients with three variants of PID: common variable immunodeficiency (CVID), idiopathic CD4 lymphopenia (ICL) and combined immunodeficiency (CID). We retrospectively compared demographics, immunological characteristics, clinical presentations and outcomes of CVID, CID and ICL patients followed from 2012 to 2018. In our cohort, we identified 44 adult patients diagnosed with CVID (22), CID (11) and ICL (11). Malignancy was associated with CID, as seven of 11 patients in this group were diagnosed with malignancy compared to CVID (three of 22) or ICL (two of 11) (P = 0·002 and 0·03, respectively). Malignancies were also linked to male gender [odds ratio (OR) = 5, 95% confidence interval (CI) = 1·12–22·18) P = 0·0342] and a low ratio of CD4/CD8 < 0·8 (OR = 5·1, 95% CI = 1·22–21·28, P = 0·025). Among CID and ICL, two of 11 patients died in each group, while no death was documented among CVID group (P = 0·04). Autoimmune manifestations did not differ between groups. Similarly, the rate of infections was similar between groups, although infectious agents vary. CID is associated with a high risk of malignancy compare to CVID or ICL. Among adults with PID, male gender, low CD4 and a CD4/CD8 ratio of < 0·8 may serve as risk factors of concomitant malignancy. Surveillance of lymphocyte subpopulations should be considered for all adults.
Biallelic loss of function variant in the unfolded protein response gene PDIA6 is associated with asphyxiating thoracic dystrophy and neonatal‐onset diabetes
Authors: Al‐Fadhli Fatima M. , Afqi Manal , Sairafi Mona Hamza , Almuntashri Makki , Alharby Essa , Alharbi Ghadeer , Abdud Samad Firoz , Hashmi Jamil Amjad , Zaytuni Dimah , Bahashwan Ahmed A. , Choi Jin Huk , Peake Roy W. A. , Beutler Bruce , Almontashiri Naif A. M.
Published: January 2021

Protein disulfide isomerase A6 (PDIA6) is an unfolded protein response (UPR)‐regulating protein. PDIA6 regulates the UPR sensing proteins, Inositol requiring enzyme 1, and EIF2AK3. Biallelic inactivation of the two genes in mice and humans resulted in embryonic lethality, diabetes, skeletal defects, and renal insufficiency. We recently showed that PDIA6 inactivation in mice caused embryonic and early lethality, diabetes and immunodeficiency. Here, we present a case with asphyxiating thoracic dystrophy (ATD) syndrome and infantile‐onset diabetes. Whole exome sequencing revealed a homozygous frameshift variant in the PDIA6 gene. RNA expression was reduced in a gene dosage‐dependent manner, supporting a loss‐of‐function effect of this variant. Phenotypic correlation with the mouse model recapitulated the growth defect and delay, early lethality, coagulation, diabetes, immunological, and polycystic kidney disease phenotypes. In general, the phenotype of the current patient is consistent with phenotypes associated with the disruption of PDIA6 and the sensors of UPR in mice and humans. This is the first study to associate ATD to the UPR gene, PDIA6. We recommend screening ATD cases with or without insulin‐dependent diabetes for variants in PDIA6.
An adapting soft computing model for intrusion detection system
Authors: Alsaadi Husam Ibrahiem Husain , ALmuttari Rafah M. , Ucan Osman Nuri , Bayat Oguz
Published: January 2021

Network security in smart cities has become a key problem in the rapid development of computer networks over the past few years. Intrusion detection systems play a fundamental part in the integrity, confidentiality, and resource accessibility among the multiple network security policies. The classification of the genuineness of packets is main object of the presents research work, the soft computing has applied to classify the genuineness of packets. The complexity of soft computing is greatly reduced if the numbers of features in a dataset are reduced. Managing and analysis of the dimensionality reduction is novelty of the proposed model. The existence of uncertainty and the imprecise nature of the intrusions appear to create suitable fuzzy logic systems for such structures. The neural‐fuzzy algorithm is one of the effective methods that incorporate fuzzy logic systems into adaptive and analysis capacities. In this research work, soft computing fuzzy logic system is proposed to enhance network security through intrusion detection. Three network datasets are demonstrated to test and estimate the proposed system. Feature selection has used to remove irrelevant features from entire network data which are obstacle classification processes. The Information Gain method was applied to select importance features for detection intrusion. Adaptive Neuro‐Fuzzy Inference System (ANFIS) is further used to process the significant features of the classification network data as normal or attacks packets. Two functions named Jang's Neuro‐fuzzy and faster‐scaled conjugate gradient (SCG) based on the ANFIS system. Obviously, the experimental results demonstrate the proposed system has attained higher precision in detecting normal or attack. The experimental results have suggested that the proposed system results are better in accuracy and time process for classification compared with the existing models. The Overall Results show that the proposed system can be able to detect various intrusions efficiently and effectively.
The AudioMaze: An EEG and motion capture study of human spatial navigation in sparse augmented reality
Authors: Miyakoshi Makoto , Gehrke Lukas , Gramann Klaus , Makeig Scott , Iversen John
Published: January 2021

Spatial navigation is one of the fundamental cognitive functions central to survival in most animals. Studies in humans investigating the neural foundations of spatial navigation traditionally use stationary, desk‐top protocols revealing the hippocampus, parahippocampal place area (PPA), and retrosplenial complex to be involved in navigation. However, brain dynamics, while freely navigating the real world remain poorly understood. To address this issue, we developed a novel paradigm, the AudioMaze, in which participants freely explore a room‐sized virtual maze, while EEG is recorded synchronized to motion capture. Participants (n = 16) were blindfolded and explored different mazes, each in three successive trials, using their right hand as a probe to “feel” for virtual maze walls. When their hand “neared” a virtual wall, they received directional noise feedback. Evidence for spatial learning include shortening of time spent and an increase of movement velocity as the same maze was repeatedly explored. Theta‐band EEG power in or near the right lingual gyrus, the posterior portion of the PPA, decreased across trials, potentially reflecting the spatial learning. Effective connectivity analysis revealed directed information flow from the lingual gyrus to the midcingulate cortex, which may indicate an updating process that integrates spatial information with future action. To conclude, we found behavioral evidence of navigational learning in a sparse‐AR environment, and a neural correlate of navigational learning was found near the lingual gyrus.
Completeness and representativeness of body mass index in children's electronic general practice records: Linked cross‐sectional study in an ethnically‐diverse urban population in the United Kingdom
Authors: Firman Nicola , Robson John , Ahmed Zaheer , Boomla Kambiz , Dezateux Carol
Published: January 2021

Objective

To assess completeness and accuracy of children's body mass index (BMI) recorded in general practice electronic health records (GP‐EHRs).

Methods

We linked National Child Measurement Programme (NCMP) records from 29 839 5‐year‐olds and 26 660 11‐year‐olds attending state schools in inner London to GP‐EHRs (95% linked; 49.1% girls). We estimated adjusted odds (aOR) of at least one GP‐BMI record by sex, ethnic background, area‐level deprivation, weight‐status and long‐term conditions. We examined within‐child BMI differences and compared obesity prevalence from these sources.

Results

10.5% (2964/28330) and 26.0% (6598/25365) of 5‐ and 11‐year‐olds respectively had at least one GP‐BMI record. Underweight (aOR;95% CI:1.71;1.34,2.19), obesity (1.45;1.27,1.65), South Asian background (1.55;1.38,1.74), presence of a long‐term condition (8.15;7.31,9.10), and residence in deprived areas (Wald statistic 38.73; P‐value<0.0001) were independently associated with at least one GP‐BMI record. NCMP‐BMI and GP‐BMI differed by +0.45(95% Limits of Agreement −1.60,+2.51) and + 0.16(−2.86,+3.18) in 5‐ and 11‐year‐olds, respectively. The prevalence of obesity based on GP‐BMI was 18.2%(16.1,20.5) and 35.9%(33.9,38.0) in 5‐ and 11‐year‐olds respectively, compared to 12.9%(12.5,13.3) and 26.9%(26.4,27.4) based on NCMP‐BMI.

Conclusion

Child BMI is not comprehensively recorded in urban general practice. Linkage to school measurement records is feasible and enables assessment of health outcomes of obesity.
Development of livestock feed additives using porcine blood cells
Authors: Choi Jae‐Hwan , Jung Tae‐Hwan , Seo Hyeon‐Ju , Han Kyoung‐Sik
Published: January 2021

Livestock blood discarded during slaughtering has potentially valuable components such as plasma proteins and haemoglobin. Plasma is used as a feed additive following processing via different methods, including spray drying, whereas blood cells have been underutilized. In this study, we developed haemoglobin hydrolysate (HH) and iron‐enriched residue (IER) from porcine blood cells and investigated whether their oral administration regulates the immune system and gut microbiota in growing rats. Twenty‐one Sprague‐Dawley male rats (n = 7) were used during a 4‐week trial and were fed a control, HH or IER diet. The ratio of beneficial bacteria such as Lactobacillus and Akkermansia strains increased in rats fed HH or IER diets. Moreover, compared with the control group, the IER group had an elevated ratio of Lactobacillus to Enterobacteria, which is regarded as an index of beneficial aspect in the gut. Phagocytosis of peripheral blood leucocytes was higher in the HH and IER groups than in the control group. The level of plasma immunoglobulin G increased to approximately 72.7 mg/ml and 152.0 mg/ml in the HH and IER groups, respectively, which was significantly (p < 0.05) higher than that in the control group. These results confirm that HH and IER developed in this study may be a potential additive for animal feeds.
Comparison of the effects on tablet disintegration of solvents used to dissolve food thickeners
Authors: Matsuo Taisuke , Sasaki Hina , Tomita Takashi , Sadzuka Yasuyuki
Published: January 2021

Food thickening agents help patients with dysphagia to eat, drink, and take medications. Taking medications with food thickeners has been reported to cause problems such as reduction of pharmacological effects through the delayed disintegration or non‐disintegration of tablets. We previously reported that long immersion periods in food thickeners causes delayed disintegration and non‐disintegration, while an immersion time of 1 min prevents these problems. However, in many studies including ours, water was used as the solvent, and patients with dysphagia use various drinks as food thickener solvents. Therefore, in this study, we examined the effects on tablet disintegration of food thickeners dissolved in 12 solvents. The line spread test (LST) and pH of the food thickeners differed among solvents, whereas the disintegration times of tablets immersed in food thickeners for 1 min were similar. Magnesium oxide tablets immersed in food thickeners for 30 min experienced delayed disintegration or non‐disintegration in all solvents. These results suggested that the effects of solvents on the disintegration of medications hardly differ. Therefore, patients taking medications with food thickeners may refer to reports in which water was used as the solvent, regardless of their drink of choice.
Production risk, technical efficiency, and input use nexus: Lessons from Bangladesh aquaculture
Authors: Khan Md. Akhtaruzzaman , Begum Ratna , Nielsen Rasmus , Hoff Ayoe
Published: January 2021

The optimal use of resources in aquaculture is important, especially in developing countries, to obtain the highest possible outcome from the production process to support food security and poverty alleviation. Thus, within this study, the risk, efficiency, and input‐use variation in aquaculture farms in Bangladesh is investigated using a flexible stochastic frontier model with a risk and an inefficiency function. The results reveal that feed, labor, and capital have positive and significant impacts on production. In addition, an increased fingerling density and a larger farm increase the risk, whereas the use of feed and the capital invested have the opposite effect. Access to extension services has a positive effect and increases farm efficiency. An investigation of the farm size–productivity inverse relationship reveals that this phenomenon is not applicable to Bangladesh aquaculture. In general, efficient farmers are large‐scale farmers, who use a lower stocking density but a higher feeding intensity, resulting in a higher yield. On average, farmers use less labor and feed than what is optimal. To increase efficiency and reduce risk, it is recommended that more technical knowledge on optimal input use, extension service, and capital is made available to aquaculture farmers.
Metals in eggs and hatchlings of Dermochelys coriacea (testudines) in Espírito Santo, Brazil and their relation to hatching and emergence success
Authors: Borini Freire Jordana , Sousa Rafael M. , Taufner Karla , Carneiro Maria TW , Filgueiras Henrique R , Lenz Dominik , Ferreira Paulo Dias , C Endringer Denise
Published: January 2021

Certain concentration of metal may influence survival in embryonic stages, reducing the birthrate and hatching emergence. This study aimed to evaluate concentration of metal in eggs and hatchlings of Dermochelys coriacea and correlate metal concentrations in eggs with hatching and emergence success. The samples were collected at Biological Reserve Station, ES, Brazil. At the nests' opening, unhatched eggs and stillborn hatchlings were collected to survey the successful hatching and emergence of D. coriacea. The eggs shell, egg content, and dead hatchlings metal concentrations were compared to hatching and emergence success. A positive correlation was found between the concentration of copper (Cu) in the hatchlings and the success of the emergence (r2 = .28, p < .05), and a moderate positive correlation between the concentrations of iron (Fe) and barium (Ba; r2 = .44, p < .05) and success hatching. The concentrations of metals in eggs and hatchlings of D. coriacea in the Espírito Santo are below the levels that could be considered harmful to the species. In summary, there is a positive correlation between metals levels and hatching and emergence success.
Effect of Mechanical Strain on Cells Involved in Fracture Healing
Authors: Duan Zheng‐wei , Lu Hua
Published: January 2021

Secondary fracture healing is a complex multi‐stage process in which the mechanical environment plays a key role. The use of an appropriate mechanical stimulation such as strain is conducive to tissue formation between fracture ends, thus aiding the healing process. However, if the strain is too large or too small, the biological behavior of the cells involved in bone healing will be affected, resulting in non‐union or delayed healing. In this review, we summarize the current state of knowledge regarding the effect of strain on cells that play a role in the fracture‐healing process. Overall, the related literature suggests that selection of an adequate strain promotes fracture healing through the stimulation of angiogenesis and osteogenesis, along with inhibition of osteoclast differentiation and bone resorption. However, standardized methods for the application of mechanical stimulation are lacking, and a unified consensus on the mechanism by which strain promotes cell differentiation has not yet been reached. These issues, therefore, deserve further investigation.
Teaching romantic competence skills to emerging adults: A relationship education workshop
Authors: Davila Joanne , Zhou Jiaqi , Norona Jerika , Bhatia Vickie , Mize Lauren , Lashman Kaycee
Published: January 2021

Romantic relationships are a central component of life and are linked to well‐being, making adaptive functioning critical. Yet, there are few theory‐driven, systematic efforts to prepare young people to function skillfully. This study reports the results of a randomized controlled trial of a two‐session relationship education program based on Davila and colleagues' construct of romantic competence. Participants were 154 (68 relationship education, 86 waitlist) emerging adult college students. They completed questionnaires initially, posttest, and at follow up. Compared to the waitlist, relationship education participants reported increases in workshop‐relevant knowledge, perspective taking, and adaptive decision making, all targets of the program. Qualitative data from relationship education participants at follow up indicated behavioral changes reflective of workshop material. This provides preliminary support of the program's efficacy.
Evidence‐based intervention program for reducing obesity among African‐American women in Southern California
Authors: Onyegbule Patience , Iyiegbuniwe Emmanuel , Sarter Barbara , James Kathy (Shadle)
Published: January 2021

Objective

This study evaluated the effectiveness of group motivational education and empowerment program using evidence‐based approaches for obesity and weight loss management for African‐American Women.

Design

This study employed a quasi‐experimental time series design based on the theoretical frameworks of the Empowerment and Health Belief models.

Sample

Twenty‐eight African‐American Women were recruited into culturally appropriate and responsive weight‐loss management program.

Measurements

The weight management programs consisted of nutrition education, physical activities, and focus‐group sessions. Measurements included analysis of blood samples for cholesterol, waistline, body mass index, and exercise time. Statistical analysis compared program outcomes at baseline and 3‐month intervals for 1 year.

Intervention

Participants were educated on healthy food choices and physical activities based on National Institutes of Health's food guidelines.

Results

The results showed that 90% of participants lost 20 pounds or more and 82% had 6 inches or more waist circumference reductions. Additionally, cholesterol reductions and improved nutrition knowledge and exercises were significant.

Conclusions

We developed an evidence‐based and culturally appropriate intervention for weight‐loss management among African‐American women. Acceptance of personal responsibility to modify behaviors, knowledge of good nutrition, and engagement in physical activities were positive and effective health behavioral changes in promoting health and weight‐loss management for this population.
Coping with low moisture stress: Remembering and responding
Authors: Choudhary Mukesh , Singh Alla , Rakshit Sujay
Published: January 2021

Low‐moisture stress, also referred to as drought, is one of the major factors that negatively impact the agricultural yield. The present scenario of climate change is expected to aggravate it further. Considering the extended time required to develop resistant crops, it is important to prioritize research efforts for coping with low moisture, prevalent in arid and semi‐arid regions of the world. While agricultural yield is a tradeoff between many choices, tolerance to biotic and abiotic stresses comes with yield penalties. To balance the tradeoffs and maximize productivity, the use of region‐specific cultivars and/or introgression of precise genetic proportions in an elite variety may prove useful. Stress memory is an emerging approach that helps plants to record and respond to repeated stress in an effective manner. In this context, we discuss the role of “stress memory” in imparting drought tolerance in plants. Future research efforts for its effective deployment for “drought hardening” in agricultural settings, along with a discussion on the yield tradeoff involved, is implicated.
Motivaciones hacia la actividad física de adolescentes, adultos mayores y exdeportistas de élite: Un análisis cualitativo
Authors: Pallarés Susana , Miró Salvador , Pérez-Rivases Andrea , Torregrossa Miquel , Ramis Yago , Cruz Jaume , Viladrich Carme
Published: January 2021

Objetivo. Explorar las similitudes y diferencias de los tipos de motivación hacia la práctica de actividad física (AF) de adolescentes, adultos mayores y exdeportistas de élite, desde la Teoría de la Autodeterminación, para la creación de programas de AF. Método. La recolección de los datos se llevó a cabo mediante grupos focales: tres con adolescentes, dos con adultos mayores y uno con exdeportistas. En total, participaron 17 adolescentes, 14 adultos mayores y cuatro exdeportistas. Se realizó un análisis temático. Resultados. Para cada grupo se encontró un conjunto de factores de motivación autónoma, controlada y amotivacionales hacia la práctica de AF. En común, en los tres grupos estudiados, se identificaron la diversión, la socialización y la salud como factores de motivación hacia la práctica de AF. Conclusión. Las orientaciones para la creación de programas de AF para adolescentes se centraron en la individualización de sus objetivos y la percepción en la libertad de elección relacionada con cada AF. En adultos mayores, el enfoque fue hacia nuevas experiencias, considerando de forma significativa el perfil del monitor. Para el grupo de exdeportistas se propone que el punto de partida sea la reconceptualización de la práctica de AF después de la carrera deportiva.
Relación entre ansiedad competitiva y cooperación deportiva en equipos de vela de competición
Authors: Salom Martorell Miquel , Núñez Prats Antonio , Ponseti Francisco Javier , García-Mas Alejandro
Published: January 2021

Objetivo. Analizar la relación entre la ansiedad competitiva y la cooperación deportiva en regatistas de competición de las Islas Baleares (España). Método. Se contó con una muestra de 46 regatistas de las Islas Baleares (Medad = 31.9 años; DTedad = 16.32), de diferentes niveles. Se aplicó el cuestionario Sport Anxiety Scale para la medida de la ansiedad competitiva y el Cuestionario de Cooperación Deportiva para el estudio de la cooperación. Se recogieron los datos de forma telemática y con ellos se llevó a cabo un análisis descriptivo y correlacional. Resultados. El análisis estadístico mostró correlaciones positivas y significativas, con el estadístico Pearson, entre la disposición de cooperación condicionada y todos los componentes de la variable ansiedad (Somática = 0.47, Preocupación = 0.51, Desconcentración = 0.52 y Global = 0.59). También se encontró una correlación positiva entre la ansiedad global y los componentes cognitivos de la misma, especialmente en la ansiedad por preocupación (Preocupación = 0.91 y Desconcentración = 0.84). Conclusión. El principal hallazgo del estudio fue la correlación significativa y positiva entre la cooperación condicionada y todos los componentes de la ansiedad competitiva.
Static Performance of a Hydrostatic Thrust Foil Bearing for Large Scale Oil-Free Turbomachines
Authors: LaTray Nguyen , Kim Daejong , Song Myongsok
Published: January 2021

This work presents a novel design of a hydrostatic thrust foil bearing (HSTFB), with an outer diameter of 154 mm, along with simulation and test results up to a specific load capacity of 223 kPa (32.3 psi). This bearing has high load capacity, low power loss, and no friction/wear during startup and shutdown. In addition, the HSTFB allows for bidirectional operation. The paper also presents an advanced simulation model that adopts the exact locations of tangentially arranged bumps to a cylindrical two-dimensional plate model of the top foil. This method predicts top foil deflection with better accuracy than the traditional independent elastic foundation model, which distributes the bump locations over the nodal points in the cylindrical coordinates, and with less computational resources than the finite element method applied to the entire bumps/top foils. The presented HSTFB was designed for organic Rankine cycle (ORC) generators, but its performance was predicted and measured using air in this paper. The bearing static performance is compared analytically against the rigid counterpart and presented at different supply pressures, speeds, and minimum film thicknesses. Experimental verification is conducted at 10, 15, and 20 krpm. The measured load capacity and frictional loss agree well with the prediction. The measured film thickness also agrees with the prediction after the structural deflection of the thrust runner disk is compensated. Overall, the novel HSTFB demonstrates excellent static performance and good potential for the intended ORC generators and other large oil-free turbomachines.
Probabilistic Fracture Mechanics for Mature Service Frame Rotors
Authors: Engels Philipp , Amann Christian , Schmitz Sebastian , Kadau Kai
Published: January 2021

Large gas turbine design and service business are challenged with increased demands toward flexible operations, increasing number of start-stop cycles, and intermediate cycles. Probabilistic fracture mechanics simulation design tools have matured and became robust and reliable. We present a probabilistic reevaluation of Siemens E-class turbine disks by the combination of probabilistic two-dimensional axisymmetric part analysis of the disk and a novel probabilistic approach for the three-dimensional blade attachment. The first addresses the risk of inherent forging flaws, the latter combines the risk of surface crack initiation, growth, and failure. Both models consider the heterogeneous nature of material properties, flaw geometries, and detectability. These novel concepts developed at Siemens allow for an optimization of resource usage and safety, as well as the development of new service and inspection concepts for a variety of service frames and classes.
Three-Dimensional Glucose/Oxygen Biofuel Cells Based on Enzymes Embedded in Tetrabutylammonium Modified Nafion
Authors: Hui Yuchen , Ma Xiaoyan , Cai Rong , Minteer Shelley D.
Published: January 2021

A stable three-dimensional glucose/oxygen enzymatic biofuel cell is fabricated based on the method of polymer encapsulation-based immobilization. And three-dimensional carbon felt is used as the substrate of the bio-electrode for increasing enzymatic loading density. Gold nanoparticles and multi-wall carbon nanotubes are employed to promote direct electron transfer and enhance conductivity and electron conduction rate of bio-electrodes. Glucose dehydrogenase and bilirubin oxidase are immobilized with tetrabutylammonium bromide (TBAB) modified Nafion, which enhances the stability of the bio-electrodes by the immobilization method. A membrane-free glucose/oxygen biofuel cell is assembled with a high open-circuit voltage of 0.85 V and a maximum power density of 21.9 ± 0.1 μW/cm2 in 0.1 M pH 7.0 phosphate buffer solution with 100 mM glucose and air saturation. And the biofuel cell shows high stability to the condition. After 60 days of periodic storage experiments, the performance of the enzymatic biofuel cell still maintained 90.3% of its electrochemical performance.
Model Predictive Control for a Synchronous Machine With a Pulsed, Constant-Power Load
Authors: Parry Adam , Hencey Brandon , Zumberge Jon
Published: January 2021

In this paper, the problem of controlling synchronous machines driving high pulsed, constant-power loads (CPLs) with fast ramp rates is investigated. Using a PI controller to provide offset-free tracking of the generator voltage in steady state, we design controllers using Model Predictive Control which act as a reference governor to ensure power quality constraints are met during transients. However, it is shown that a standard linear MPC algorithm creates a steady state offset due to model mismatch at off-nominal power levels resulting in loss of power quality. This problem is corrected by creating multiple linear models of the generator dynamics linearized around the nominal and high power operating points. We then demonstrate that a Hybrid Model Predictive Control algorithm (using the constrained piecewise affine prediction model) exhibits zero offset during the high power pulse. The Hybrid MPC algorithm also keeps the generator voltage within the required constraints. This approach has the benefit of correcting the model mismatch issue without using a computationally expensive nonlinear Model Predictive Control algorithm. Future work will focus on implementing and testing this hybrid MPC controller on a generator via explicit MPC techniques.
Experimental and Analytical Nonzero-Sum Differential Game-Based Control of a 7-DOF Robotic Manipulator
Authors: Bagheri Mostafa , Bertino Alexander , Naseradinmousavi Peiman
Published: January 2021

We formulate a Nash-based feedback control law for an Euler-Lagrange system to yield a solution to non-cooperative differential game. The robot manipulators are broadly utilized in industrial units on the account of their reliable, fast, and precise motions, while consuming a significant lumped amount of energy. Therefore, an optimal control strategy needs to be implemented in addressing efficiency issues, while delivering accuracy obligation. As a case study, we here focus on a 7-DOF robot manipulator through formulating a two-player feedback nonzero-sum differential game. First, coupled Euler-Lagrangian dynamic equations of the manipulator are briefly presented. Then, we formulate the feedback Nash equilibrium solution in order to achieve perfect trajectory tracking. Finally, the performance of the Nash-based feedback controller is analytically and experimentally examined. Simulation and experimental results reveal that the control law yields almost perfect tracking and achieves closed-loop stability.
Cutting the Deployment Costs of Physics-Based MPC in Buildings by Simulation-Based Imitation Learning
Authors: Drgona Jan , Helsen Lieve , Vrabie Draguna L.
Published: January 2021

It has been shown that model predictive control (MPC) is a promising solution for energy-efficient building operations. However, the deployment of MPC in a large portion of the building stock has not been possible partially because of high installation costs. Every building is unique and requires a tailored MPC solution. The best performing solutions are often based on physics-based modeling, which is, however, computationally expensive and requires dedicated software. A promising direction that tackles this problem is to train a neural network-based optimal control policy to imitate the behavior of physics-based MPC from the simulation data generated offline. The neural networks give control actions that closely approximate those produced by physics-based MPC, but with a fraction of the computational and memory requirements and without the need for licensed software. The main advantage of the proposed approach stems from simple evaluation at execution time, leading to low computational foot-prints and easy deployment on embedded HW platforms. In the case study, we present the energy savings potential of physics-based MPC applied to an office building in Belgium. We demonstrate how neural network approximators can be used to cut the implementation and maintenance costs of MPC deployment without compromising performance. We also critically assess the presented approach by pointing out the remaining challenges and open research questions.