bluuebunny/crossref_metadata_2025 huggingface dataset:
TRPM channels mediate learned pathogen avoidance following intestinal distention
Authors: Filipowicz Adam , Lalsiamthara Jonathan , Aballay Alejandro
Published: May 2021

Upon exposure to harmful microorganisms, hosts engage in protective molecular and behavioral immune responses, both of which are ultimately regulated by the nervous system. Using the nematode Caenorhabditis elegans, we show that ingestion of Enterococcus faecalis leads to a fast pathogen avoidance behavior that results in aversive learning. We have identified multiple sensory mechanisms involved in the regulation of avoidance of E. faecalis. The G-protein coupled receptor NPR-1-dependent oxygen-sensing pathway opposes this avoidance behavior, while an ASE neuron-dependent pathway and an AWB and AWC neuron-dependent pathway are directly required for avoidance. Colonization of the anterior part of the intestine by E. faecalis leads to AWB and AWC mediated olfactory aversive learning. Finally, two transient receptor potential melastatin (TRPM) channels, GON-2 and GTL-2, mediate this newly described rapid pathogen avoidance. These results suggest a mechanism by which TRPM channels may sense the intestinal distension caused by bacterial colonization to elicit pathogen avoidance and aversive learning by detecting changes in host physiology.
Genome-wide CRISPRi screening identifies OCIAD1 as a prohibitin client and regulatory determinant of mitochondrial Complex III assembly in human cells
Authors: Le Vasseur Maxence , Friedman Jonathan , Jost Marco , Xu Jiawei , Yamada Justin , Kampmann Martin , Horlbeck Max A , Salemi Michelle R , Phinney Brett S , Weissman Jonathan S , Nunnari Jodi
Published: May 2021

Dysfunction of the mitochondrial electron transport chain (mETC) is a major cause of human mitochondrial diseases. To identify determinants of mETC function, we screened a genome-wide human CRISPRi library under oxidative metabolic conditions with selective inhibition of mitochondrial Complex III and identified ovarian carcinoma immunoreactive antigen (OCIA) domain-containing protein 1 (OCIAD1) as a Complex III assembly factor. We find that OCIAD1 is an inner mitochondrial membrane protein that forms a complex with supramolecular prohibitin assemblies. Our data indicate that OCIAD1 is required for maintenance of normal steady-state levels of Complex III and the proteolytic processing of the catalytic subunit cytochrome c1 (CYC1). In OCIAD1 depleted mitochondria, unprocessed CYC1 is hemylated and incorporated into Complex III. We propose that OCIAD1 acts as an adaptor within prohibitin assemblies to stabilize and/or chaperone CYC1 and to facilitate its proteolytic processing by the IMMP2L protease.
Introducing the MAVEN Leadership Training Initiative to diversify the scientific workforce
Authors: Wang Y Claire , Brondolo Elizabeth , Monane Rachel , Kiernan Michaela , Davidson Karina W ,   The MAVEN Leadership Team, Alfano Catherine M , Diamond Betty , Duer-Hefele Joan , Hill-Briggs Felicia , Kim Jerry , Peacock James , Spector Nancy D , Yoon Sunmoo
Published: May 2021

Addressing gender and racial-ethnic disparities at all career stages is a priority for the research community. In this article, we focus on efforts to encourage mid-career women, particularly women of color, to move into leadership positions in science and science policy. We highlight the need to strengthen leadership skills for the critical period immediately following promotion to associate/tenured professor – when formal career development efforts taper off while institutional demands escalate – and describe a program called MAVEN that has been designed to teach leadership skills to mid-career women scientists, particularly those from underrepresented groups.
An analysis of the locality of binary representations in genetic and evolutionary algorithms
Authors: Shastri Hrishee , Frachtenberg Eitan
Published: May 2021

Mutation and recombination operators play a key role in determining the performance of Genetic and Evolutionary Algorithms (GEAs). Prior work has analyzed the effects of these operators on genotypic variation, often using locality metrics that measure the sensitivity and stability of genotype-phenotype representations to these operators. In this paper, we focus on an important subset of representations, namely nonredundant bitstring-to-integer representations, and analyze them through the lens of Rothlauf’s widely used locality metrics. Our main research question is, does strong locality predict good GEA performance for these representations? Our main findings, both theoretical and empirical, show the answer to be negative. To this end, we define locality metrics equivalent to Rothlauf’s that are tailored to our domain: thepoint localityfor single-bit mutation andgeneral localityfor recombination. With these definitions, we derive tight bounds and a closed-form expected value for point locality. For general locality we show that it is asymptotically equivalent across all representations and operators. We also reproduce three established GEA empirical results to understand the predictive power of point locality on GEA performance, focusing on two popular and often juxtaposed representations: standard binary and binary-reflected Gray.
partR2: partitioning R2in generalized linear mixed models
Authors: Stoffel Martin A. , Nakagawa Shinichi , Schielzeth Holger
Published: May 2021

The coefficient of determinationR2quantifies the amount of variance explained by regression coefficients in a linear model. It can be seen as the fixed-effects complement to the repeatabilityR(intra-class correlation) for the variance explained by random effects and thus as a tool for variance decomposition. TheR2of a model can be further partitioned into the variance explained by a particular predictor or a combination of predictors using semi-partial (part)R2and structure coefficients, but this is rarely done due to a lack of software implementing these statistics. Here, we introducepartR2, an R package that quantifies partR2for fixed effect predictors based on (generalized) linear mixed-effect model fits. The package iteratively removes predictors of interest from the model and monitors the change in the variance of the linear predictor. The difference to the full model gives a measure of the amount of variance explained uniquely by a particular predictor or a set of predictors.partR2also estimates structure coefficients as the correlation between a predictor and fitted values, which provide an estimate of the total contribution of a fixed effect to the overall prediction, independent of other predictors. Structure coefficients can be converted to the total variance explained by a predictor, here called ‘inclusive’R2, as the square of the structure coefficients times totalR2. Furthermore, the package reports beta weights (standardized regression coefficients). Finally,partR2implements parametric bootstrapping to quantify confidence intervals for each estimate. We illustrate the use ofpartR2with real example datasets for Gaussian and binomial GLMMs and discuss interactions, which pose a specific challenge for partitioning the explained variance among predictors.
Effects of Extreme Flooding on Output of Selected Crops in Anambra State, Nigeria from 1990 to 2019
Authors: Nkechi Uche , Ikechukwu N. Nte
Published: May 2021

The study has analyzed effects of extreme flooding on output of selected root and tuber crops in Anambra State, Nigeria for the period of 1990-2019using secondary data collected on cassava, yam and sweet potato output from the agricultural production survey of Anambra State Agricultural Development Programme and annual averages of rainfall from the Nigeria Meteorological Agency inAwka station. Data collected were analysed by using multivariate simple linear regression and trend analysisin linear trend analysis and line graph. Results respectively showed an increasing trend in output of cassava, yam and sweet potato within the researched period with a depression in output of cassava and yam in 2014 and 2015. The regression results showed that coefficients of determination (R2) values of yam output were (0.620), cassava output (0.560) and sweet potato (0.580), which implied that 63%, 56% and 58% changed in output of roots and tuber crops accounted for rainfall within the research period. Specifically, rainfall (0.002) was positively related to yam output at (p<0.05). This implied excessive amount of rainfall resulting flooding, which influenced the output of production of yam. Rainfall (-0.015) and (-0.003) were negatively related to output of cassava and sweet potato at 5% probability level, which indicated extreme rainfall translating into flooding, which adversely affected the output of cassava and sweet potato in this area. The result of the tested hypothesis showed that extreme flooding had significant negative effects on output of roots and tuber crops in the researched area. Based on results, it was concluded that extreme flooding deleteriously affected output of root and tuber crops in Anambra state, Nigeria. Therefore, farmers were advised to change their crop production technologies including time of planting to suit changes in rainfall pattern in order to avert their adverse effects.
Determination and Analysis of Metals in Freshwater Microalgae (Chlorella vulgaris and Spirulina platensis) through Total Reflection X-ray Fluorescence Spectroscopy (TXRF)
Authors: Bungudu J. I. , Murphy Lorrie M.
Published: May 2021

This work investigates the concentration of some trace elements in freshwater microalgae ( Chlorella vulgaris and Spirulina platensis) through total reflection x-ray fluorescence spectroscopy (TXRF). Slurry samples were prepared from 3.4 ± 0.5 to 9.8 ± 0.5 mg of freeze-dried algae biomass for direct metals analysis. Gallium was used as internal standard at concentration of 500 µg/L and the solution was mixed for 15 second using vortex. The concentrations of different metals including Magnesium (Mg), Zinc (Zn), Phosphorus (P), Sulphur (S), Copper (Cu), Potassium (K), Calcium (Ca), Manganese (Mn) and Iron (Fe) were determined in the ranged 6.8 ± 1.7 – 15709 mg/kg. A similar study investigated the total macro and micronutrient profile Chlorella vulgaris and the published data agree with current study. Statistical analysis shows that only Ba has significant difference between Chlorella vulgaris and Spirulina platensis (P = 0.05) The two investigated algal species shows a measurable concentration using TXRF of metals such as manganese, iron, copper, and zinc. TXRF shows good accuracy with ability to determine sample in small quantities (µl) In conclusion, the sensitivity of TXRF technique can also be seen in determining elements with lower atomic number such as Ca, P and K.
Development and Validation of an Emotional Intelligence Test for Medical Students
Authors: Deepa R. , Panicker Anuja S.
Published: May 2021

Aims: Emotional intelligence is an important ability that has to be fostered among medical professionals. To foster an ability, it has to be assessed. The tests/tools already available are culture-sensitive and context-sensitive. Hence there is a need to develop a test to assess the emotional intelligence abilities of medical students. This paper describes a multiphase study in which an instrument was developed to assess the emotional intelligence of medical students.

Study Design:  The study was done in four phases. The first three phases were to develop the instrument and establish its reliability and validity. The fourth phase was to demonstrate the predictive validity of the developed instrument.

Place and Duration of Study: A private teaching hospital in South India; Two years.

Methodology: In the first phase, the emotional challenges of medical students (n =55) were understood to develop the situations for the situational judgment tests. In the second phase, the instrument was developed with 38 items contributing to the constructs of EI. In the third phase, a pilot study was conducted, in which the developed tool was administered on a sample of 150 medical students. The data was used to verify the content validity, construct validity, internal consistency reliability (0.8), and predictive validity. In the fourth phase (n = 102) the test-retest reliability (with a ten-month interval between the tests) and the predictive validity (established by studying the association between EI measured with the tool and the academic performance of respondents) of the purified instrument were studied.

Results: A tool to assess the EI of medical students was developed. The tool demonstrated test-retest reliability (0.6) and predictive validity (r = 0.29; P < .01).

Conclusion: The tool would provide a premise for the development of training programs and their inclusion in the medical curriculum, which in turn would yield medical professionals who can deliver enhanced patient care. The study also showed the impact of EI on the academic achievement of medical students and hence their knowledge and skills will also be improved by including EI in their curriculum.
Acute Post Streptococcal Glomerulonephritis among Children from Sokoto, North-Western Nigeria
Authors: Jiya Fatima Bello , Ibitoye Paul Kehinde , Jiya Nma Muhammed , Abba Mohammed Hassan
Published: May 2021

Aims: To determine the clinical and laboratory profile of children with acute post streptococcal glomerulonephritis (APSGN) admitted into Usmanu Danfodiyo University Teaching Hospital (UDUTH) Sokoto, the outcome, and factors associated with in-hospital mortality.

Study Design: A 5- year retrospective study.

Place of Study: Emergency Paediatric Unit (EPU) and Paediatric Medical Ward (PMW) of the Department of Paediatrics, UDUTH Sokoto.

Methodology: The records of children aged 4 to 14 years with the diagnosis of APSGN were reviewed. Relevant history, physical examination findings, laboratory and radiologic investigation findings were extracted from their case folders and recorded into a proforma sheet. Data was analyzed using SPSS version 23. (IBM SPSS Inc., USA). The level of statistical significance was set at 5%, which is p-value < 0.05.

Results: Fifty-four (0.9%) of the 6128 children were managed for APSGN giving a prevalence of 10.8 APSGN cases per 1000 children. Forty-one folders were utilized for the study. There were 21(51.2%) females and 20(48.8%) males, with F:M ratio of 1.1:1. Mean age at presentation was 9.1± 3.1 years. Majority (92.6%) were ≥5 years and mainly 22(53.7%) of low socio-economic status. The main features were body swelling 40(97.6%), fever 25(61.0%), oliguria 24(58.5%), systemic hypertension 37(90.2%), proteinuria 41(100.0%), and haematuria 41(100.0%). Acute kidney injury was the commonest 25(61.0%) complication. Thirty (73.2%) cases were discharged, 5 (12.2%) died, 6(14.6%) left against medical advice. Low social status (0.03), requirement for dialysis (p=0.003), congestive cardiac failure (p=0.01), and pulmonary oedema (p=0.04) were significantly associated with in-hospital mortality. Requirement for dialysis (p=0.005) was the independent predictor of in-hospital mortality. At three months post discharge, 20(48.8%) of the 31 cases had achieved complete resolution of APSGN.

Conclusion: APSGN is common in Sokoto and similar in pattern to other reports from Nigeria. The presence of complications at presentation increases the risk of in-hospital mortality.
Abundance and Seasonality of Phytoplankton, Zooplankton and Anuran Species in Selected Wetlands of Kogi State, Nigeria
Authors: Amana G. U. , Ozougwu J. C. , Okoye I. C. , Imakwu C. A. , Okeke O. P. , Ogbodo J. C. , Idakwo J.
Published: May 2021

Phytoplankton, Zooplankton and anurans play vital role in the working of wetland ecosystems as they form its dynamic food web. This study was designed to determine the abundance and seasonality of Phytoplankton, Zooplankton and Anuran species in selected wetlands of Kogi State, Nigeria. The study was performed in Abu’ja wetland in Dekina Local Government area and Egwubi seasonal wetland in Ejule, Ofu Local Government area of Kogi state. From each sampled wetlands planktons were collected with plankton net at the sites. Overall, 854 specimens of anurans, 584 from Abu’ja and 270 from Egwubi sites were collected within a period of eighteen months. The abundance of phytoplankton, zooplankton and anuran species were computed. Abundance was computed as a proportion of numbers of organisms in a group to the summation of the total number in all the groups being considered. Simpson’s index (Dominance), Gini-Simpson's, Shannon-Wiener index, Berger-Parker index, Margalef’s index, Menhinick’s index, Fisher alpha, Equitability index, Brillouin index and Chao index were all calculated following standard methods. The data collected was analyzed using the Statistical Package for Social Sciences (SPSS) version 20.0, PAST version 3.14 and Microsoft Office. Level of significance was p < 0.05. Anuran species found in both wetlands included Amietophrymus regularis, A. maculatus and Hoplobatracchus occipitalis. Phytoplankton species encountered in both study stations include Oscilatoria spp, Anabaenia spp, Anacystis spp, Spirogyra spp, Oedogonium spp, Savicular spp and Euglena spp. Zooplanktons encountered include Epiphanes spp, Philodina spp, Synchata spp, Poliathra spp, Holopedium spp, Daphnia spp, Alona spp and Bosmina spp. The abundance and seasonality of phytoplankton, zooplankton and anurans in the selected wetlands studied in Kogi state, Nigeria showed that the organisms abundance are highly influenced by the seasons in Kogi State, with its peak abundance in rainy season and very low abundance in dry season.
Interplay between Performance and Convenience in Customer Choice of Self-Service Technologies
Authors: Galdolage Badra Sandamali
Published: May 2021

Technological enhancements bring more convenience to customers by providing opportunities to do various service transactions through Self Service Technologies (SSTs). However, a very few studies focused on understanding SSTs profoundly. Thus, this research focuses on exploring performance and convenience related to SSTs in detail. Based on the inductive research approach, qualitative interviews were conducted with 25 SST users and data were analyzed using thematic analysis approach. The study found eight performance features; ‘usefulness, speed, efficiency, consistency, cost-effectiveness, user-friendliness, reliability, trialability’ and three convenience features; ‘locational convenience, time convenience and physical exertion’ as important in customer choice of SSTs. This study fills the gap in the literature by discussing two important matters in customer choice of SSTs in detail. It opens theoretical lenses to understand the significance of self-service technologies to customers from its performance and convenience perspectives. It provides useful insights for SST service providers that can be incorporated to their SSTs in designing and delivering a high-quality service which matches with the customer expectations.
The use of Geoeletric Methods for Post-foundation Assessments of Distressed Buildings in Ebute-meta, Mainland Local Government Area of Lagos State
Authors: Airen O. J.
Published: May 2021

Geophysical and geotechnical investigations were combined to investigate the immediate causes of the distresses and foundation failures of buildings in Ebute-Meta area of Lagos, south-west Nigeria. Six (6) traverses were mapped in the study area across which six (6) 2D Wenner ERI, and fourteen (14) VES geophysical data were acquired. One (1) boring and five (5) CPT geotechnical data were also acquired. 2D ERI results reveal that resistivity values vary from 4.62 – 293 Ωm across the study area. Three resistivity structures were identified which denoted peat/clay, sandy clay, clayey sand and sand. The resistivity of the peat/clay varies from 4.62 – 27.9 Ωm with thickness varying from 12 - 25 m. The sandy clay varies in resistivity and thickness values from 26 – 86 Ωm and 8 – 29 m respectively. The clayey sand from 84.4 – 182 Ωm and 10 -15 m, and sand, having resistivity and thickness values of 293 Ωm and 3 – 5 m. The VES reveals similar results to the 2D ERI, delineating six geoelectric layers which are the topsoil, peat, clay, sandy clay, clayey sand and sand at maximum depth of 35.8 m. The borehole (BH) reveals a maximum boring depth of 45 m with eight zones comprising dark grey sandy clay, firm to stiff silty clay, soft, dark organic silty peaty clay, grey silty sand, dark grey silty sandy clay, dark grey organic peaty clay, grey silty sandy clay and medium dense to dense grey sand with occasional gravels. The CPT, which penetrated a maximum depth 15.8 m reveal that the cone resistance values vary progressively from 0 – 162 kg/cm2indicating very soft clay to soft clay near-surface and medium dense to dense geologic material at deeper depth. The peat/clay delineated by the 2D ERI and VES at 5 – 25 m depth with resistivity value varying from 4.62 -17 Ωm in the study area, and also revealed in the BH at 5.75 – 27.75 m depth as soft, dark organic silty peaty clay, having cone resistance values varying from 0 – 20 kg/cm2 is laterally extensive and incompetent to support engineering foundation.
Assessing the Association between the Methylenetetrahydrofolate Reductase (MTHFR) 677C->T Polymorphism on Blood Folate Concentrations: A Systematic Review and Meta-analysis of Trials and Observational Studies
Authors: Tsang Becky , Cordero Amy , Marchetta Claire , Mulinare Joseph , Mersereau Patricia , Guo Jing , Qi Yan Ping , Berry R. J. , Rosenthal Jorge , Crider Krista
Published: May 2021

Objectives: The methylenetetrahydrofolate reductase (MTHFR) 677C->T polymorphism is a risk factor for neural tube birth defects (NTDs). The T allele produces an enzyme with reduced folate processing capacity, which has been shown to produce lower blood folate concentrations in some studies. Our objective was to assess the association between MTHFR C677T genotypes (CC, CT, TT) and blood folate concentrations among women aged 12-49 years.

Methods: We conducted a systematic review of literature published between 1/1992-7/2013 to identify controlled trials and observational studies that reported serum, plasma, or red blood cell (RBC) folate concentrations and MTHFR C677T genotype. We applied a Bayesian random-effects model to predict differences in blood folate concentrations between MTHFR C677T genotypes, stratified by folate assay.

Results: Thirty-eight studies met criteria for inclusion. Serum/plasma folate concentrations showed a consistent genotype trend with the highest concentrations for CC (CC > CT > TT) regardless of assay type. RBC folate concentrations measured by microbiologic assay also demonstrated this trend; however, this trend was reversed (CC < CT < TT) in studies using protein-binding assays.

Conclusions: Meta-analyses results showed blood folate concentrations differed by assay type and genotype. Previous evidence has shown that RBC folate concentrations measured with a radioimmunoassay requires adjustment for genotype-dependent folate recovery; our results suggest that other protein-binding assays could have similar limitations. Compared to CC individuals, TT individuals have lower blood folate concentrations, which may increase a woman's risk for an NTD-affected pregnancy.
Effects of Locally Produced and Consumed Vegetables on Anthropometric Indices and Micronutrient Intakes of Preschoolers in Vegetables Home Garden Households in Owerri Municipality
Authors: Onyemaechi C. O. Asinobi Chinagorom , Nkiru Oly-Alawuba
Published: May 2021

Objective: To assess the effect of vegetable home garden on anthropometric indices and micronutrient intakes of preschoolers in households producing and consuming vegetables in Owerri Municipality.

Methodology: Anthropometric measurements of 90 preschoolers aged 4 months- 60months were taken from 76 vegetables home garden households (VHGH) and 52 preschoolers from 39 non vegetable home garden households (NVHGH). Growth deviations from median, percentage prevalence and severities of under nutrition were calculated bases on the National Centre for Health Statistics (NCHS) reference. Also calculated were mean daily food nutrient intakes and adequacy ratios using food composition table.

Associations between anthropometric indicators of the preschoolers and levels of micronutrient intakes were assessed. Significance of differences was determined by Chi-Square and students t-test.

Results: On average the nutrient adequacy ratios of both males and females were lower than requirements in iron, riboflavin, and niacin in both households.  However, the growth deviations of the preschoolers were above median - <2SD but higher in preschoolers in VHGH than their counterparts. The differences in the growth deviations were significant and highest in the age group 48 – 60months in both households but higher in VHGH than in NVHGH. There were significant associations between the anthropometric indices of the preschoolers and the levels of micronutrient intakes in VHGH.

Conclusions: Preschoolers in VHGH that produced and consumed home produced vegetables had better anthropometric indices and micronutrient intakes than their counterparts. Vegetables home garden practices in urban areas should be encouraged to alleviate the problem of micronutrient deficiencies in preschoolers.
Improving the Accuracy of Iodization of the Dietary Salt Supplies of Populations
Authors: Jooste Pieter , Haar Frits Van Der
Published: May 2021

Objectives: The mandate of this working group was to assess the importance of salt iodine quality in successful IDD prevention and control. Examine the role of salt iodine content in quality assurance, inspection, surveillance, and coalition oversight of IDD programs.

Methods: Scientific literature, technical reports and a range of data and information sources were reviewed to determine whether accurate salt iodization was making a critical contribution toward safe and successful IDD programs.

Results: Evidence and examples were collected on salt iodine data in quality assurance of iodization by salt industry, assessments of iodized salt quality by inspectors in factories and markets, surveillance of USI strategies and dietary iodine supplies by program managers, and in provision of coalition oversight by high-level officials.

Conclusions: Because salt iodization is a supply-based strategy, reliable accuracy at the source is most critical. It is therefore vital that each salt factory should adopt a quality management system, with standard operating procedures at least for the manufacturing and packaging of iodized salt. Titration is preferred but other quantitative methods with e.g. the WYD Checker, i-Reader or Bioanalyt can also yield accurate data. Improved accuracy down the supply chain is desirable, especially in surveillance, but commonly points to the need for ensured accuracy at the source when quality failures are discovered. The need remains for an agreed approach to obtain reliable data of the use of iodized salt in the food manufacturing industry.
Assessment of Meteorological Drought with Application of Standardized Precipitation Evapotranspiration Index (SPEI) for Tripura, Northeast India
Authors: Sharma Aribam Priya Mahanta , Jhajharia D. , Yurembam G. S. , Gupta S.
Published: May 2021

Drought is one of the major water-related natural hazards. Understanding the spatial and temporal variation of rainfall is of great importance in water resources planning and management as it is related with food security and management of scarce water resource, which becomes critical in case of drought events. The advent of GIS to produce spatially interpolated drought map helps the water managers to undertake appropriate measures in drought relief and prioritization of drought mitigation works. Limitation of literature on Tripura suggests that study of drought over Tripura could help in strengthening of mitigation planes and rationalization of disaster management policies. Hence, the present study is focused to investigate the drought persistence and severity in the Tripura state of India during the period 1980-2013, using Standardized Precipitation Evapotranspiration Index (SPEI). Three time scale i.e., 3, 6 and 12 month time scales were opted for the study. Gridded monthly precipitation data distributed over the four districts of Tripura was used for drought analysis. Significant drought events were detected over the study area during the selected period. Annual analysis of SPI time series showed that the study area received the intense drought during the year 1985. Geospatial technique was used to generate the SPEI drought map for the year 1985.
Seroprevalence and Risk Factors Associated with Human Immunodeficiency Virus Infection Type 1 in Donors of the National Blood Transfusion Center of Libreville (Gabon)
Authors: Mangala Christian , Nkoa Therese , Maulot-Bangola Denis , Codjo Franck Vivien Vigan , Fokam Joseph
Published: May 2021

Background: Transmission of HIV through blood transfusion remains a public health problem, particularly in countries in Sub-Saharan Africa. However, no study has determined the epidemiological data regarding HIV-1 infection in Gabonese blood donors. The objective of this study is to assess the seroprevalence of HIV-1 and the risk factors associated with infection in donors from the National Blood Transfusion Center in Libreville (Gabon).

Methods: A cross-sectional study carried out from June to August 2020 in 3669 persons donating blood at the National Blood Transfusion Center (NBTC). The ELISA technique (Evolis®, BioRad), the chemiluminescence technique (Cobas® e601, Roche), and the SD Bioline® HIV 1/2 test (Standard Diagnostics. Inc) were used for the detection of anti-HIV-1/2 antibodies and P24 antigen in donor plasma. Data were analyzed using SPSS software version 21.0, with p˂.05 considered statistically significant. 

Results: The seropositivity rate HIV-1 was 0.8% (30/3669) (95% CI: 0.5; 1.1). The study was composed of 79.4% men and 20.6% women. The most representative age group was of 25-34 years with 54.5%. The seropositivity of men, women, and unrelated voluntary donors was 0.7%, 1.2%, and 1.0%, respectively. The risk factors such as the first blood donation (Adjusted Odds Ratio (AOR) = 0.1 [0.0 ;0.4], P= .002), multiple sexual partners (AOR = 6.2 [2.2;17.2], P= .001), primary educational level (AOR = 10.1 [1.4;75], P = .024), and dental care (AOR = 3.6 [1.2;11], P = .024) were significantly associated with HIV infection. About 0.14% of the patients had co-infection.

Conclusion: In the Gabonese context, about one out of a hundred blood donors are HIV-infected. These carriers of HIV infection in the blood banks are mainly new donors with multiple sexual partners, limited education, and poor dental care.
Polyphenols Content and Antioxidant Activity of Bilberry Juice Obtained from Different Altitude Samples
Authors: Papanov Stoyan I. , Petkova Ekaterina G. , Ivanov Ivan G.
Published: May 2021

There are about 30 different types of blueberries. In Bulgaria, there are 4 species of genus Vaccinium - red (vitis-idaea), black (myrtillus), blue (uliginosum) and Caucasian (arctostaphylos). Bilberries are a source of carotene, vitamin B1, vitamin B2, potassium, sodium, calcium, magnesium, phosphorus, iron, vitamin D, manganese, soluble and insoluble fibres like pectin. Blueberries contain significant amounts of anthocyanidins, antioxidants and ellagic acid. The main wealth of blueberries are the antioxidants that bind free radicals and thus prevent malignant tumors. This is why blueberry is an excellent remedy for oncology.

Objective of study was to investigate the content of total polyphenols, antioxidant activity and total anthocyanins of bilberry depending on altitude.

Systematic approach and critical analysis of the available scientific periodicals and DPPH method for determining the antioxidant activity (radical trapping activity).

It has been established a direct relationship between altitude and antioxidant activity. In the range of 900 to 1450 m the relationship between altitude and total anthocyanins is inversely proportional. After 1500 m, the dependency becomes proportional. There is no correlation between pH, total polyphenols and titratable acidity.
Class A G protein‐coupled receptors assemble into functional higher‐order hetero‐oligomers
Authors: Gao Xianlong , Enten Garrett A. , DeSantis Anthony J. , Majetschak Matthias
Published: May 2021

Although class A seven‐transmembrane helix (7TM) receptor hetero‐oligomers have been proposed, information on the assembly and function of such higher‐order hetero‐oligomers is not available. Utilizing bioluminescence resonance energy transfer (BRET), bimolecular luminescence/fluorescence complementation (BiLC/BiFC), and BiLC/BiFC BRET in HEK293T cells, we provide evidence that chemokine (C‐X‐C motif) receptor 4, atypical chemokine receptor 3, α1a‐adrenoceptor, and arginine vasopressin receptor 1A form hetero‐oligomers composed of 2–4 different protomers. We show that hetero‐oligomerization per se and ligand binding to individual protomers regulate agonist‐induced coupling to the signaling transducers of interacting receptor partners. Our findings support the concept that receptor hetero‐oligomers form supramolecular machineries with molecular signaling properties distinct from the individual protomers. These findings provide a mechanism for the phenomenon of context‐dependent receptor function.
Automation and integration of a novel restricted single‐isocenter stereotactic body radiotherapy (a‐RESIST) method for synchronous two lung lesions
Authors: Critchfield Lana Sanford , Visak Justin , Bernard Mark E , Randall Marcus E , McGarry Ronald C , Pokhrel Damodar
Published: May 2021

Synchronous treatment of two lung lesions using a single‐isocenter volumetric modulated arc therapy (VMAT) stereotactic body radiation therapy (SBRT) plan can decrease treatment time and reduce the impact of intrafraction motion. However, alignment of both lesions on a single cone beam CT (CBCT) can prove difficult and may lead to setup errors and unacceptable target coverage loss. A Restricted Single‐Isocenter Stereotactic Body Radiotherapy (RESIST) method was created to minimize setup uncertainties and provide treatment delivery flexibility. RESIST utilizes a single‐isocenter placed at patient’s midline and allows both lesions to be planned separately but treated in the same session. Herein is described a process of automation of this novel RESIST method. Automation of RESIST significantly reduced treatment planning time while maintaining the benefits of RESIST. To demonstrate feasibility, ten patients with two lung lesions previously treated with a single‐isocenter clinical VMAT plan were replanned manually with RESIST (m‐RESIST) and with automated RESIST (a‐RESIST). a‐RESIST method automatically sets isocenter, creates beam geometry, chooses appropriate dose calculation algorithms, and performs VMAT optimization using an in‐house trained knowledge‐based planning model for lung SBRT. Both m‐RESIST and a‐RESIST showed lower dose to normal tissues compared to manually planned clinical VMAT although a‐RESIST provided slightly inferior, but still clinically acceptable, dose conformity and gradient indices. However, a‐RESIST significantly reduced the treatment planning time to less than 20 min and provided a higher dose to the lung tumors. The a‐RESIST method provides guidance for inexperienced planners by standardizing beam geometry and plan optimization using DVH estimates. It produces clinically acceptable two lesions VMAT lung SBRT plans efficiently. We have further validated a‐RESIST on phantom measurement and independent pretreatment dose verification of another four selected 2‐lesions lung SBRT patients and implemented clinically. Further development of a‐RESIST for more than two lung lesions and refining this approach for extracranial oligometastastic abdominal/pelvic SBRT, including development of automated simulated collision detection algorithm, merits future investigation.
Strain Effects on Rashba Spin‐Orbit Coupling of 2D Hole Gases in GeSn/Ge Heterostructures
Authors: Tai Chia‐Tse , Chiu Po‐Yuan , Liu Chia‐You , Kao Hsiang‐Shun , Harris C. Thomas , Lu Tzu‐Ming , Hsieh Chi‐Ti , Chang Shu‐Wei , Li Jiun‐Yun
Published: May 2021

A demonstration of 2D hole gases in GeSn/Ge heterostructures with a mobility as high as 20 000 cm2 V−1 s−1 is given. Both the Shubnikov–de Haas oscillations and integer quantum Hall effect are observed, indicating high sample quality. The Rashba spin‐orbit coupling (SOC) is investigated via magneto‐transport. Further, a transition from weak localization to weak anti‐localization is observed, which shows the tunability of the SOC strength by gating. The magneto‐transport data are fitted to the Hikami–Larkin–Nagaoka formula. The phase‐coherence and spin‐relaxation times, as well as spin‐splitting energy and Rashba coefficient of the k‐cubic term, are extracted. The analysis reveals that the effects of strain and confinement potential at a high fraction of Sn suppress the Rashba SOC caused by the GeSn/Ge heterostructures.
Electronic Modulation of Non‐van der Waals 2D Electrocatalysts for Efficient Energy Conversion
Authors: Wang Hao , Chen Jianmei , Lin Yanping , Wang Xiaohan , Li Jianmin , Li Yao , Gao Lijun , Zhang Labao , Chao Dongliang , Xiao Xu , Lee Jong‐Min
Published: May 2021

The exploration of efficient electrocatalysts for energy conversion is important for green energy development. Owing to their high surface areas and unusual electronic structure, 2D electrocatalysts have attracted increasing interest. Among them, non‐van der Waals (non‐vdW) 2D materials with numerous chemical bonds in all three dimensions and novel chemical and electronic properties beyond those of vdW 2D materials have been studied increasingly over the past decades. Herein, the progress of non‐vdW 2D electrocatalysts is critically reviewed, with a special emphasis on electronic structure modulation. Strategies for heteroatom doping, vacancy engineering, pore creation, alloying, and heterostructure engineering are analyzed for tuning electronic structures and achieving intrinsically enhanced electrocatalytic performances. Lastly, a roadmap for the future development of non‐vdW 2D electrocatalysts is provided from material, mechanism, and performance viewpoints.
Intact Vertical 3D–0D–2D Carbon‐Based p–n Junctions for Use in High‐Performance Photodetectors
Authors: Feng Xiaoqiang , He Zhengyi , Liu Zhiduo , Zhu Wei , Zhao Menghan , Yang Siwei , Guo Qinglei , Chen Da , Ding Guqiao , Wang Gang
Published: May 2021

Ultrathin 2D graphene (2D‐Gr) sheets have inherently weak absorption characteristics (only 2.3%). Pristine‐graphene‐based photodetectors therefore have short carrier lifetimes and small Schottky barriers that severely restrict their practical application. In this work, chemical vapor deposition (CVD) and dynamic plasma‐assisted CVD (PACVD) are used to grow vertical p–n junctions in situ, which can then be used to form novel near‐infrared photodetectors. The directly formed vertical heterostructures feature 0D C3N quantum dots (QDs) in the middle position which acts as nucleation seeds to directly and rapidly grow 3D graphene (3D‐Gr) structures that act as the n‐type region. The bottom layer consists of a single‐crystal 2D‐Gr film that forms the p‐type region. The large built‐in electric field at the interface of the depletion region of the 3D‐Gr/2D‐Gr vertical p–n junction leads to the rapid separation of any photogenerated electron–hole pairs. Thus, the photodetector exhibits an excellent responsivity of 2.98  ×  107 A W−1 and a detectivity of 1.04  ×  1013 cm  Hz1/2  W−1 at a wavelength of 1550 nm. The response speed of the photodetector is ultrafast and exceeds that of other vertical/lateral p–n‐junction‐based photodetectors. Its speed is ascribed to the synergism that exists between the C3N QDs and 3D‐Gr due to their unique electron distributions and structural distortions. The research paves the way for a novel class of high‐performance graphene‐based photodetectors with hybrid architecture.
Finding Solutions for Fibrosis: Understanding the Innate Mechanisms Used by Super‐Regenerator Vertebrates to Combat Scarring
Authors: Durant Fallon , Whited Jessica L.
Published: May 2021

Soft tissue fibrosis and cutaneous scarring represent massive clinical burdens to millions of patients per year and the therapeutic options available are currently quite limited. Despite what is known about the process of fibrosis in mammals, novel approaches for combating fibrosis and scarring are necessary. It is hypothesized that scarring has evolved as a solution to maximize healing speed to reduce fluid loss and infection. This hypothesis, however, is complicated by regenerative animals, which have arguably the most remarkable healing abilities and are capable of scar‐free healing. This review explores the differences observed between adult mammalian healing that typically results in fibrosis versus healing in regenerative animals that heal scarlessly. Each stage of wound healing is surveyed in depth from the perspective of many regenerative and fibrotic healers so as to identify the most important molecular and physiological variances along the way to disparate injury repair outcomes. Understanding how these powerful model systems accomplish the feat of scar‐free healing may provide critical therapeutic approaches to the treatment or prevention of fibrosis.
Production of a Promising Biosynthetic Self‐Assembled Nanoconjugate Vaccine against Klebsiella Pneumoniae Serotype O2 in a General Escherichia Coli Host
Authors: Peng Zhehui , Wu Jun , Wang Kangfeng , Li Xin , Sun Peng , Zhang Lulu , Huang Jing , Liu Yan , Hua Xiaoting , Yu Yunsong , Pan Chao , Wang Hengliang , Zhu Li
Published: May 2021

Klebsiella pneumoniae has emerged as a severe opportunistic pathogen with multiple drug resistances. Finding effective vaccines against this pathogen is urgent. Although O‐polysaccharides (OPS) of K. pneumoniae are suitable antigens for the preparation of vaccines given their low levels of diversity, the low immunogenicity (especially serotype O2) limit their application. In this study, a general Escherichia coli host system is developed to produce a nanoscale conjugate vaccine against K. pneumoniae using the Nano‐B5 self‐assembly platform. The experimental data illustrate that this nanoconjugate vaccine can induce an efficient humoral immune response in draining lymph nodes (dLNs) and elicit high titers of the IgG antibody against bacterial lipopolysaccharide (LPS). The ideal prophylactic effects of these nanoconjugate vaccines are further demonstrated in mouse models of both systemic and pulmonary infection. These results demonstrate that OPS with low immunogenicity can be changed into an effective antigen, indicating that other haptens may be applicable to this strategy in the future. To the knowledge, this is the first study to produce biosynthetic nanoconjugate vaccines against K. pneumoniae in E. coli, and this strategy can be applied to the development of other vaccines against pathogenic bacteria.
Juvenile xanthogranuloma in Noonan syndrome
Authors: Ali Marwan M. , Gilliam Amy E. , Ruben Beth S. , Tidyman William E. , Rauen Katherine A.
Published: May 2021

Noonan syndrome (NS) is one of the common RASopathies. While the clinical phenotype in NS is variable, it is typically characterized by distinctive craniofacial features, cardiac defects, reduced growth, bleeding disorders, learning issues, and an increased risk of cancer. Several different genes cause NS, all of which are involved in the Ras/mitogen‐activated protein kinase (Ras/MAPK) pathway. Juvenile xanthogranuloma (JXG) is an uncommon, proliferative, self‐limited cutaneous disorder that affects young individuals and may be overlooked or misdiagnosed due to its transient nature. A RASopathy that is known to be associated with JXG is neurofibromatosis type 1 (NF1). JXG in NF1 has also been reported in association with a juvenile myelomonocytic leukemia (JMML). As RASopathies, both NS and NF1 have an increased incidence of JMML. We report a 10‐month‐old female with NS who has a PTPN11 pathogenic variant resulting in a heterozygous SHP2 p.Y62D missense mutation. She was found to have numerous, small, yellow‐pink smooth papules that were histopathologically confirmed to be JXG. In understanding the common underlying pathogenetic dysregulation of the Ras/MAPK pathway in both NS and NF1, this report suggests a possible molecular association for why NS individuals may be predisposed to JXG.
Fusion imaging in brain structure measurements on a fetus phantom, combining real‐time ultrasound with magnetic resonance imaging
Authors: Arechvo Anastasija , Lingman Göran , Thurn Lars , Jansson Tomas , Jokubkiene Ligita
Published: May 2021

Objectives

To assess synchronisation of MRI and US in measuring foetus phantom head structures; inter‐method, intra‐ and inter‐observer differences on biparietal diameter (BPD), head diameter, anterio‐posterior head diameter (HAP) and lateral ventricle structures (VS).

Methods

Fusion Imaging (FI) has been performed by combining MRI and US simultaneously. Axial scans of 1.5 Tesla MRI on a foetus phantom were acquired and uploaded on a US machine (EPIQ 7G, Philips). A PercuNav US tracker allowed the system to recognise and display the position of the transducer. A fetal phantom tracker was used as a phantom reference. Real‐time US of the phantom head was performed by synchronising the uploaded MRI images using different landmarks. Synchronisation has been assessed by taking measurements after rotating the US probe by 90. Measurements were taken by three different observers twice. Differences in measurements between MRI and US, inter‐, intra‐observer differences in all measurements were assessed.

Results

BPD, HAP and VS measurements before rotation were 0.13 ± 0.06 cm, 0.46 ± 0.09 cm and 0.4 ± 0.23 cm (width) and mean 0.6 ± 0.25 cm (length) larger at MRI than at US using any number of landmarks. After US probe rotation VS were 0.3 ± 0.24 cm in width and 0.3 ± 0.27 cm in length. Intra‐ and inter‐observer differences in all measurements were small.

Conclusions

FI showed good synchronisation in measurements. BPD, HAP and VS were larger at MRI than US, likely a result of the way images are generated. Intra‐, inter‐observer differences between measurements were small. This can be important when reporting geometric measures from FI.
Modifying pathways by age and sex for the association between combined sleep disordered breathing and long sleep duration with neurocognitive decline in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)
Authors: Kaur Sonya S. , Tarraf Wassim , Wu Benson , Gonzalez Kevin A. , Daviglus Martha , Shah Neomi , Sotres‐Alvarez Daniela , Gallo Linda C. , Wohlgemuth William , Redline Susan , Gonzalez Hector M. , Ramos Alberto R.
Published: May 2021

Introduction

We aimed to determine whether obesity or metabolic syndrome (MetS) modify associations between sleep‐disordered breathing (SDB), self‐reported sleep duration (SD), and phenotypes of combined SDB/SD with 7‐year neurocognitive decline (ND) in a community based‐cohort of U.S. Hispanic/Latinos (N = 5500) in different age and sex groups.

Methods

The exposures were baseline SDB (respiratory event index ≥ 15), sleepiness (Epworth Sleepiness Scale ≥ 10), SD (< 6 hours, 6–9 hours, ≥ 9 hours). The outcome was 7‐year ND.

Results

Mean age was 56.0 years, 54.8% were females. Obesity modified the association between SDB/SD and ND in memory (F = 21.49, P < 0.001) and global cognition (F = 9.14, P < 0.001) in the oldest age group. Women without MetS with combined long sleep/SDB exhibited most pronounced decline in global cognition (F = 3.07, P = 0.010).

Discussion

The association between combined SDB/long sleep and declines in memory and global cognition was most pronounced in obese older adults. Among women, MetS status modified the association between long sleep/SDB and decline in global cognition.