bluuebunny/crossref_metadata_2025 huggingface dataset:
Essential role of the mouse synapse associated protein Syap1 in circuits for spontaneous motor activity and rotarod balance
Authors: R. von Collenberg Cora , Schmitt Dominique , Ruelicke Thomas , Sendtner Michael , Blum Robert , Buchner Erich
Published: February 2019

Synapse-associated protein 1 (Syap1) is the mammalian homologue of synapse-associated protein of 47 kDa (Sap47) in Drosophila. Genetic deletion of Sap47 leads to deficiencies in short-term plasticity and associative memory processing in flies. In mice, Syap1 is prominently expressed in the nervous system, but its function is still unclear. We have generated Syap1 knockout mice and tested motor behaviour and memory. These mice are viable and fertile but display distinct deficiencies in motor behaviour. Locomotor activity specifically appears to be reduced in early phases when voluntary movement is initiated. On the rotarod, a more demanding motor test involving control by sensory feedback, Syap1-deficient mice dramatically fail to adapt to accelerated speed or to a change in rotation direction. Syap1 is highly expressed in cerebellar Purkinje cells and cerebellar nuclei. Thus, this distinct motor phenotype could be due to a so far unknown function of Syap1 in cerebellar sensorimotor control. The observed motor defects are highly specific since other tests in the modified SHIRPA test, as well as cognitive tasks like novel object recognition, Pavlovian fear conditioning, and anxiety-like behaviour in open field, dark-light transition, and elevated plus maze, do not appear to be strongly affected in Syap1 knockout mice.
Cholesterol sensing by CD81 is important for hepatitis C virus entry
Authors: Palor Machaela , Stejskal Lenka , Mandal Piya , Lenman Annasara , Alberione Pia Maria , Kirui Jared , Moeller Rebecca , Ebner Stefan , Meissner Felix , Gerold Gisa , Shepherd Adrian J. , Grove Joe
Published: February 2019

CD81 plays a central role in a variety of physiological and pathological processes. Recent structural analysis of CD81 indicates that it contains an intramembrane cholesterol-binding pocket and that interaction with cholesterol may regulate a conformational opening of the large extracellular domain of CD81. Therefore, CD81 possesses a potential cholesterol sensing mechanism; however, the relevance of this for protein function is thus far unknown. In this study we investigate CD81 cholesterol sensing in the context of its activity as a receptor for hepatitis C virus (HCV). Structure-led mutagenesis of the cholesterol-binding pocket reduced CD81-cholesterol association, but had disparate effects on HCV entry, both reducing and enhancing CD81 receptor activity. We reasoned that this could be explained by alterations in the consequences of cholesterol binding. To investigate this further we performed molecular dynamic simulations of CD81 with and without cholesterol; this identified a potential allosteric mechanism by which cholesterol binding regulates the conformation of CD81. To test this, we designed further mutations to force CD81 into either the open (cholesterol unbound) or closed (cholesterol bound) conformation. The open mutant of CD81 exhibited reduced receptor activity whereas the closed mutant enhanced activity. These data are consistent with CD81 cholesterol sensing resulting in a switch between a receptor active and inactive state. CD81 interactome analysis also suggests that conformational switching may modulate the assembly of CD81-partner protein networks. This work furthers our understanding of the molecular mechanism of CD81 cholesterol sensing, how this relates to HCV entry and CD81’s function as a molecular scaffold; these insights are relevant to CD81’s varied roles in both health and disease.
Long-Term historical and Projected Herbivore Population Dynamics in Ngorongoro Crater, Tanzania
Authors: Ogutu Joseph O. , Moehlman Patricia D , Piepho Hans-Peter , Runyoro Victor A , Coughenour Michael B , Boone Randall
Published: February 2019

The Ngorongoro Crater is an intact caldera with an area of approximately 310 km2. Long term records on herbivore populations, vegetation and rainfall made it possible to analyze historic and project future herbivore population dynamics. In 1974 there was a perturbation in that resident Maasai and their livestock were removed from the Crater. Vegetation structure changed in 1967 from predominately short grassland to mid and tall grasses dominating in 1995. Even with a change in grassland structure, total herbivore biomass remained relatively stable from 1963 to 2012, implying that the crater has a stable multi-herbivore community. However, in 1974, Maasai pastoralists were removed from the Ngorongoro Crater and there were significant changes in population trends for some herbivore species. Buffalo, elephant and ostrich numbers increased significantly during 1974-2012. The zebra population was stable from 1963 to 2012 whereas numbers of other eight species declined substantially between 1974 and 2012 relative to their peak numbers during 1974-1976. Numbers of Grant’s and Thomson’s gazelles, eland, kongoni, waterbuck (wet season only) declined significantly in the Crater in both seasons after 1974. Wildebeest numbers decreased in the Crater between 1974 and 2012 but this decrease was not statistically significant. In addition, some herbivore species were consistently more abundant inside the Crater during the wet than the dry season. This pattern was most evident for the large herbivore species requiring bulk forage, comprising buffalo, eland, and elephant. Analyses of rainfall indicated that there was a persistent annual cycle of 4.83 years. Herbivore population size was correlated with rainfall in both the wet and dry seasons. The relationships established between the time series of historic animal counts in the wet and dry seasons and lagged wet and dry season rainfall series were used to forecast the likely future trajectories of the wet and dry season population size for each species under three alternative climate change scenarios.
Responses of soil physical, chemical and biochemical properties to short-term impact of tillage in an alfisol under maize (Zea mays L.) cultivation
Authors: Adegaye Ajoke Christianah , Adejoro Solomon , Oladele Segun , Arotupin Daniel , Ojeniyi Stephen
Published: February 2019

A short-term field and laboratory experiment was conducted to assess the impact of four traditional tillage methods on the physical, chemical and biochemical properties of a sandy clay loam alfisol under maize (Zea mays L.) cultivation following a fallow period of five years. Treatments included slash only (SO), slash +burn (SB), slash+ ridge (SR) and herbicide (glyphosate) application (HA) at the recommended rate of 2 L/ha-1. Results from the statistical analysis of data from this study showed inconsistent trends of tillage treatments on soil physical properties. However, slash +burn (SB) tillage significantly (p < 0.05) enhanced chemical properties such as the soil pH, available P, exchangeable K+, Ca2+, and Mg2+ compared to their respective values before treatment application in the two years under study. Amongst the treatments, slash + burn (SB) tillage further exerted the most significant (P ≤ 0.05) effect on urease, L-asparaginase, L-glutaminase, dehydrogenase, acid and alkaline phosphatase activities, but recorded the least values for amidase and β-glucosidase activities in soil. Results from this study therefore, suggest that SB tillage treatment was beneficial to the soil environment as it has proven to be more promising and effective for enhancing the selected soil quality indicators on the soil type due to quick mineralization and release of bound nutrients present in the soil and litter.
Kilohertz two-photon fluorescence microscopy imaging of neural activityin vivo
Authors: Wu Jianglai , Liang Yajie , Chen Shuo , Hsu Ching-Lung , Chavarha Mariya , Evans Stephen W , Shi Donqging , Lin Michael Z , Tsia Kevin K , Ji Na
Published: February 2019

Understanding information processing in the brain requires us to monitor neural activityin vivoat high spatiotemporal resolution. Using an ultrafast two-photon fluorescence microscope (2PFM) empowered by all-optical laser scanning, we imaged neural activityin vivoat up to 3,000 frames per second and submicron spatial resolution. This ultrafast imaging method enabled monitoring of both supra- and sub-threshold electrical activity down to 345 μm below the brain surface in head fixed awake mice.
Proteomic and Transcriptomic Profiling Identifies Mediators of Anchorage-Independent Growth and Roles of Inhibitor of Differentiation Proteins in Invasive Lobular Breast Cancer
Authors: Tasdemir Nilgun , Ding Kai , Levine Kevin M. , Du Tian , Bossart Emily A. , Lee Adrian V. , Davidson Nancy E. , Oesterreich Steffi
Published: February 2019

BACKGROUND

Invasive lobular carcinoma (ILC) is a histological subtype of breast cancer with distinct molecular and clinical features from the more common subtype invasive lobular carcinoma (IDC). We have previously shown that human ILC cells lines have a remarkably unique ability to grow in ultra-low attachment (ULA) suspension cultures as compared to IDC cells, the mediators of which remain unknown.

METHODS

Using flow cytometry and immunoblotting in human ILC and IDC cell lines, we measured levels of apoptosis and cell proliferation in attached (2D) and suspension (ULA) cultures. siRNA-mediated knockdown and pharmacological inhibitors were utilized to assess the effects of known regulators of anchorage-independence. Reverse Phase Protein Arrays and RNA-Sequencing were performed to identify novel proteomic and transcriptomic mediators of ULA growth in ILC cells.

RESULTS

We show that human ILC cell lines exhibit enhanced anoikis resistance and cell proliferation in ULA cultures as compared to IDC cells. Transient restoration of E-cadherin did not impact the 2D or ULA growth of human ILC cell lines, while transient E-cadherin knockdown in IDC cells partially rescued their growth defect in ULA culture. Inhibition of the Rho/ROCK, p120-catenin or YAP/Hippo pathways previously implicated in anoikis resistance did not have a major effect on the ULA growth of ILC cells. Proteomic comparison of ILC and IDC cell lines identified unique induction of PI3K/Akt and p90-RSK pathways in ULA culture in ILC cells. Transcriptional profiling uncovered unique upregulation of the Inhibitors of Differentiation family transcription factors ID1 and ID3 in ILC ULA culture, the knockdown of which diminished anchorage-independent growth. We find that ID1 and ID3 expression is higher in human ILC tumors as compared to IDC and correlated with a worse disease-specific survival uniquely in the ILC cohort.

CONCLUSION

Our comprehensive study of 2D and ULA growth in human ILC cell lines revealed anoikis resistance, cell proliferation and novel mediators of anchorage-independence and provides possible mechanistic insights and clinical implications for metastatic dissemination of ILC. High expression in human ILC tumors and association with clinical outcome implicate ID1 and ID3 as novel drivers and therapeutic targets for lobular breast cancer.
Endogenous oxytocin inhibits hypothalamic stress responsive neurons following acute hypernatremia
Authors: Pati Dipanwita , Harden Scott W. , Kelly Kyle B. , de Kloet Annette D. , Krause Eric G. , Frazier Charles J.
Published: February 2019

Significant prior evidence indicates that centrally acting oxytocin robustly modulates stress responsiveness and anxiety-like behavior, although the neural mechanisms behind these effects are not completely understood. A plausible neural basis for oxytocin mediated stress reduction is via inhibition of corticotropin-releasing hormone (CRH) neurons in the paraventricular nucleus of the hypothalamus (PVN) that regulate activation of the hypothalamic-pituitary-adrenal (HPA) axis. Previously, we have shown that following subcutaneous injection of 2.0 M NaCl, oxytocin (OT) synthesizing neurons are activated in the rat PVN, an oxytocin receptor (Oxtr) dependent inhibitory tone develops on a subset of parvocellular neurons, and stress-mediated increases in plasma corticosterone levels are blunted. Here, we utilized transgenic male CRH-reporter mice to selectively target PVN CRH neurons for whole-cell recordings. These experiments reveal that acute salt loading produces tonic inhibition of PVN CRH neurons through a mechanism that is largely independent of synaptic activity. Further studies reveal that CRH neurons within the PVN synthesize mRNA for Oxtr(s). Salt induced Oxtr-dependent inhibitory tone was eliminated in individual PVN CRH neurons filled with GDP-β-S, and was also largely absent in PVN CRH neurons extracted form CRH-Oxtr KO mice. Additional electrophysiological studies suggest that reduced excitability of PVN CRH neurons in salt loaded animals is associated with increased activation of an inwardly rectifying potassium channel. Collectively, these data reveal a likely cellular mechanism by which endogenous oxytocin signaling reduces the excitability of PVN CRH neurons to curb stress responsiveness during times of high plasma osmolality.
Evolution and rapid spread of a reassortant A(H3N2) virus that predominated the 2017-2018 influenza season
Authors: Potter Barney I. , Garten Rebecca , Hadfield James , Huddleston John , Barnes John , Rowe Thomas , Guo Lizheng , Xu Xiyan , Neher Richard A. , Bedford Trevor , Wentworth David
Published: February 2019

The 2017-2018 North American influenza season caused more hospitalizations and deaths than any year since the 2009 H1N1 pandemic. The majority of recorded influenza infections were caused by A(H3N2) viruses, with most of the virus’s North American diversity falling into the A2 clade. Within A2, we observe a subclade which we call A2/re that rose to comprise almost 70% of A(H3N2) viruses circulating in North America by early 2018. Unlike most fast-growing clades, however, A2/re contains no amino acid substitutions in the hemagglutinin (HA) segment. Moreover, HI assays did not suggest substantial antigenic differences between A2/re viruses and viruses sampled during the 2016-2017 season. Rather, we observe that the A2/re clade was the result of a reassortment event that occurred in late 2016 or early 2017 and involved the combination of the HA and PB1 segments of an A2 virus with neuraminidase (NA) and other segments a virus from the clade A1b. The success of this clade shows the need for antigenic analysis that targets NA in addition to HA. Our results illustrate the potential for non-HA drivers of viral success and necessitate the need for more thorough tracking of full viral genomes to better understand the dynamics of influenza epidemics.
The molecular basis of hypercontractility caused by the hypertrophic cardiomyopathy mutations R403Q and R663H
Authors: Sarkar Saswata S. , Trivedi Darshan V. , Morck Makenna M. , Adhikari Arjun S. , Pasha Shaik N. , Ruppel Kathleen M. , Spudich James A.
Published: February 2019

Hypertrophic cardiomyopathy (HCM) mutations in ß-cardiac myosin and myosin binding protein-C (MyBP-C) cause hypercontractility of the heart. We show that hypercontractility caused by the HCM myosin mutation R663H cannot be explained by changes in the fundamental parameters such as actin-activated ATPase, intrinsic force, velocity of pure actin or regulated thin filaments, or the pCa50 of the velocity of regulated thin filaments. The same conclusion was made earlier for the HCM myosin mutation R403Q (Nag et al. 2015). Using enzymatic assays for the number of functionally-available heads in purified human ß-cardiac myosin preparations, we provide evidence that both R403Q and R663H HCM myosin mutations cause hypercontractility by increasing the number of functionally-accessible myosin heads. We also demonstrate that the myosin mutation R403Q, but not R663H, ablates the binding of myosin with the C0-C7 fragment of myosin binding protein-C.
Performance of neural network basecalling tools for Oxford Nanopore sequencing
Authors: Wick Ryan R. , Judd Louise M. , Holt Kathryn E.
Published: February 2019

Basecalling, the computational process of translating raw electrical signal to nucleotide sequence, is of critical importance to the sequencing platforms produced by Oxford Nanopore Technologies (ONT). Here we examine the performance of different basecalling tools, looking at accuracy at the level of bases within individual reads and at majority-rules consensus basecalls in an assembly. We also investigate some additional aspects of basecalling: training using a taxon-specific dataset, using a larger neural network model and improving consensus basecalls in an assembly via additional signal-level analysis with Nanopolish. Training basecallers on taxon-specific data resulted in a significant boost in consensus accuracy, mostly due to the reduction of errors in methylation motifs. A larger neural network was able to improve both read and consensus accuracy, but at a cost to speed. Improving consensus sequences (‘polishing’) with Nanopolish somewhat negates the accuracy differences in basecallers, but pre-polish accuracy does have an effect on post-polish accuracy, so basecaller choice is still relevant even when Nanopolish is used.
In-vitro pathogen inhibition: Comparing the inhibitory effects of a complex multistrain synbiotic with simple probiotics containing the yeast Saccharomyces boulardii or Lactobacillus rhamnosus bacteria
Authors: Piatek Jacek , Sommermeyer Henning , Ciechelska-Rybarczyk Arleta , Bernatek Malgorzata
Published: February 2019

Supplementation with probiotics is considered as alternative treatment or adjuvant therapy for a number of bacterial infections for which the use of antibiotics is either not recommended or emerging antibiotic resistance is a major concern. Inhibition of the growth of pathogenic bacteria has been related to a number of different activities of probiotic bacteria or yeasts, some of which are very specific for particular strains of probiotics. As the different inhibition activities might act additively or even synergistically, probiotic multistrain products are discussed as potentially being more effective in pathogen inhibition than products containing one or a small number of probiotic strains. The present study investigated the in vitro inhibition of Escherichia (E.) coli, Shigella spp., Salmonella (S.) typhimurium and Clostridum (Cl.) difficile, all being human pathogens of significant worldwide healthcare concerns. The probiotic containing the yeast Sacharomyces (S.) boulardii inhibited all four pathogens. Similar inhibitions were observed with a bacterial probiotic containing three different strains (Pen, E/N and Oxy) of Lactobacillus (Lc.) rhamnosus. Compared to the inhibition found for these probiotics, the inhibitory effects of a complex multistrain synbiotic, containing nine different probiotic strains (6 Lactobacilli and 3 Bifidobacteria) and the prebiotic fructooligosaccharide (FOS), were significantly stronger. The stronger inhibition by the complex multistrain synbiotic was observed for all four tested pathogens. Our findings support a hypothesis that complex synbiotic products containing a larger number of different strains combined with a prebiotic component might be more attractive candidates for further clinical characterization than simpler probiotics containing one or only few probiotic strains.
Tobacco use and associated factors among Rwandan youth aged 15-34 years: Findings from a nationwide survey, 2013
Authors: Habiyaremye François , Rwunganira Samuel , Musanabaganwa Clarisse , Muhimpundu Marie Aimée
Published: February 2019

Introduction

Tobacco use is the single most preventable cause of death in the world. The objective of this study was to determine the prevalence of current tobacco use and identify associated factors among Rwandans aged 15-34 years.

Methods

This cross-sectional analytical study analysed secondary data collected during the nationally representative Non-Communicable Disease Risk Factors Surveillance survey conducted in 2013 to explore the prevalence of tobacco use in Rwanda and identify factors associated with tobacco use. This study analysed data collected from 3,900 youth participants (15-34 years old), selected using multistage cluster sampling technique. The overall proportion of current smokers, as well as demographic and socioeconomic characteristics of the sample were determined and multivariable logistic regression employed to identify factors independently associated with current tobacco use.

Results

The prevalence (weighted) of current tobacco use (all forms) was 8% (95%CI: 7.08-9.01). Prevalence statistically significant was found in the following group: higher prevalence was found among males, young adults aged 24-34, youth with primary school education or less, those from Southern province, people with income (work in public, private organizations and self-employed) and young married adults.

There was no statistically significant difference in prevalence of tobacco use between participants from urban or rural areas (7.8% vs. 8.0%). Factors that were found to be associated with current tobacco use through the multivariate analysis included being a male, aged 25 years and above, having an income, and residing in Eastern, Kigali City and Southern Province compared to Western province.

Conclusion

The association between smoking and sociodemographic characteristics among Rwandan youth identified in this study provides an opportunity for policy makers to tailor future policies, and implement coordinated, high-impact interventions to prevent initiation of tobacco use among the youth.
Estimating the rate and determinants of exclusive breastfeeding practices among rural mothers in Southern Ghana
Authors: Manyeh Alfred Kwesi , Amu Alberta , Ekey Rosemond Akpene , Akpakli David Etsey , Williams John E. , Gyapong Margaret
Published: February 2019

Background

The health benefits of exclusive breastfeeding practices in both short and long term go beyond the breastfed infant. The benefits of exclusive breastfeeding practices accrue to mothers, families and the society at large. Despite the evidence of these benefits and adoption of various WHO strategies on promotion of exclusive breastfeeding by Ghana, the increase in the rate of exclusive breastfeeding has been very slow in the country. This study aimed to estimate the rate and investigate socioeconomic and demographic determinants of exclusive breastfeeding in two rural districts in Southern Ghana.

Methods

Pregnancy, childbirth, breastfeeding, demographic and socioeconomic information of 1,870 women prospectively registered by the Dodowa Health and Demographic Surveillance System and gave birth between January 1, 2011 and December 31, 2013 was extracted. The rate of exclusive breastfeeding among the study participants was estimated and the relationship between the dependent and the independent variables were explored using logistics regression model at 95% confidence level. All data analyses were done in STATA version 14.2.

Results

The overall exclusive breastfeeding rate in the study is 70.96 %. Mothers aged 25-29 and 30+ years are 93 and 91 % respectively more likely to practice exclusive breastfeeding compared to those aged <20 years (OR:1.93, 95%CI: 1.25-2.99, OR: 1.91, 95%CI: 1.91-3.08). The odds of artisans practicing exclusive breast feeding is 64% less likely compared to those unemployed (OR: 0.64, 95%CI:0.43-0.96). There is a high chance that 45% of mothers with a household size of more than five members to practice exclusive breastfeeding compared to those with household size of less than six (OR:1.45, 95%CI:1.16-1.81). There is reduced odds of 15% for women in fishing districts compared to those from farming districts (OR:0.15, 95%CI: 0.12 −0.20).

Conclusion

There is high rate of exclusive breastfeeding in the study area. Maternal age, type of occupation, household size and district of residence are determinants of exclusive breastfeeding among the study participants.
The cloud forest in the Dominican Republic: diversity and conservation status
Authors: Ortiz Ana Cano , Musarella Carmelo M. , Canas Ricardo Quinto , Fuentes José C. Piñar , Gomes Carlos J. Pinto , Cano Eusebio
Published: February 2019

The study of the forest in rainy environments of the Dominican Republic reveals the presence of four types of vegetation formations, clearly differentiated from each other in terms of their floristic and biogeographical composition, and also significantly different from the rainforests of Cuba. This leads us to propose two new alliances and four plant associations located in northern mountain areas exposed to moisture-laden winds from the Atlantic: All. Rondeletio ochraceae-Clusion roseae (Ass. Cyatheo furfuracei-Prestoetum motanae; Ass. Ormosio krugii-Prestoetum montanae); and All. Rondeletio ochraceae-Didymopanion tremuli (Ass. Hyeronimo montanae-Magnolietum pallescentis; Hyeronimo dominguensis-Magnolietum hamorii). Due to human activity, some areas are very poorly conserved, as evidenced by the diversity index and the presence of endemic tree and plant elements. The worst conserved in terms of the relationship between characteristic plants vegetation (cloud forest) in areas with high rainfall in the Dominican Republic, along with its floristic diversity and state of conservation. Thanks to this study it has been possible to significantly increase the botanical knowledge of this important habitat.
Spatial eco-evolutionary feedbacks mediate coexistence in prey-predator systems
Authors: Colombo Eduardo H. , Martínez-García Ricardo , López Cristóbal , Hernández-García Emilio
Published: February 2019

Eco-evolutionary frameworks can explain certain features of communities in which ecological and evolutionary processes occur over comparable timescales. In the particular case of prey-predator systems, a combination of empirical and theoretical studies have explored this possibility, showing that the evolution of prey traits, predator traits or the coevolution of both can contribute to the stability of the community, as well as to the emergence of various types of population cycles. However, these studies overlook that interactions are spatially constrained, a crucial ingredient known to foster species coexistence per se. Here, we investigate whether evolutionary dynamics interacts with the spatial structure of a prey-predator community in which both species show limited mobility and predators perceptual ranges are subject to natural selection. In these conditions, our results unveil an eco-evolutionary feedback between species spatial mixing and predators perceptual range: different levels of species mixing select for different perceptual ranges, which in turn reshape the spatial distribution of preys and their interaction with predators. This emergent pattern of interspecific interactions feeds back to the efficiency of the various perceptual ranges, thus selecting for new ones. Finally, since prey-predator mixing is the key factor that regulates the intensity of predation, we explore the community-level implications of such feedback and show that it controls both coexistence times and species extinction probabilities.

Author summary

Evolutionary processes occurring on temporal scales that are comparable to those of ecological change can result in reciprocal interactions between ecology and evolution termed eco-evolutionary feedbacks. Such interplay is clear in prey-predator systems, in which predation alters the distribution of resources (preys). In turn, changes in the abundance and spatial distribution of preys may lead to the evolution of new predation strategies, which may change again the properties of the prey population. Here, we investigate the interplay between limited mobility, species mixing, and finite perception in a prey-predator system. We focus on the case in which predator perceptual ranges are subject to natural selection and examine, via coexistence times and species extinction probabilities, whether the resulting eco-evolutionary dynamics mediates the stability of the community. Our results confirm the existence of such eco-evolutionary feedback and reveal its potential impact on community-level processes.
Loss of function of the RNA export factor,Nxt1, inDrosophilacauses muscle degeneration and reduced expression of genes with long introns
Authors: van der Graaf Kevin , White-Cooper Helen
Published: February 2019

The RNA export pathway is essential for export-competent mRNAs to pass from the nucleus into the cytoplasm, and thus is essential for protein production and normal function of cells.Drosophilawith partial loss of function ofNxt1, a core factor in the pathway, show reduced viability and male and female sterility. The male sterility has previously been shown to be caused by defects in testis-specific gene expression, particularly of genes without introns. Here we describe a specific defect in growth and maintenance of the larval muscles, leading to muscle degeneration inNxt1mutants. RNAseq revealed reduced expression of mRNAs of many genes inNxt1mutant muscles. Despite this, the degeneration was rescued by increased expression of a single gene, the costamere componenttn (abba),in muscles. Genes under-expressed in the mutant typically have long introns, and most normally encode circular RNAs in addition to mRNAs. This is the first report of a specific role for the RNA export pathway geneNxt1in muscle integrity. Our data onNxt1links the mRNA export pathway to a global role in mRNA expression of genes that also produce circular RNAs,in vivo.

Author summary

In eukaryotic cells the DNA encoding instructions for protein synthesis is located in the nucleus, it is transcribed to generate pre-mRNA, which is processed at both ends and spliced to remove internal spacer regions (introns) to generate mRNA. This mRNA is then transported by the mRNA export pathway via nuclear pores to the cytoplasm for protein synthesis. We have previously shown that reduction in activity of a specific protein in the mRNA export pathway, Nxt1, has an additional role in testis-specific transcription. Here we describe a further role for this protein specifically in gene expression, particularly of genes with long introns, and in muscle maintenance.Drosophilalarvae with reduced Nxt1 activity have normal muscle pattern when they are small, but show muscular atrophy and degeneration as they grow, resulting in significant defects in their movement speed. We discovered that expression of many genes is reduced in the mutant larvae, but that restoring the expression of just one of these,abba, theDrosophilahomologue ofTrim32(a human gene involved in muscular dystrophy) is capable of preventing the muscle degeneration.
Frequent expansion of Plasmodium vivax Duffy Binding Protein in Ethiopia and its epidemiological significance
Authors: Lo Eugenia , Hostetler Jessica B. , Yewhalaw Delenasaw , Pearson Richard D. , Hamid Muzamil M. A. , Gunalan Karthigayan , Kepple Daniel , Ford Anthony , Janies Daniel A. , Rayner Julian C. , Miller Louis H. , Yan Guiyun
Published: February 2019

Plasmodium vivax invasion of human erythrocytes depends on the Duffy Binding Protein (PvDBP) which interacts with the Duffy antigen. PvDBP copy number varies between P. vivax isolates, but the prevalence of PvDBP multiplications in Sub-Saharan Africa and its impact are unknown. We determined the prevalence and type of PvDBP duplications, as well as PvDBP copy number variation among 178 Ethiopian P. vivax isolates using a PCR-based diagnostic method, a novel quantitative real-time PCR assay and whole genome sequencing. For the 145 symptomatic samples, PvDBP duplications were detected in 95 isolates, of which 81 had the Cambodian and 14 Malagasy-type PvDBP duplications. PvDBP varied from 1 to >4 copies. Isolates with multiple PvDBP copies were found to be higher in symptomatic than asymptomatic infections. For the 33 asymptomatic samples, PvDBP was detected with two copies in two of the isolates, and both were the Cambodian-type PvDBP duplication. PvDBP copy number in Duffy-negative heterozygotes was not significantly different from that in Duffy-positives, providing no support for the hypothesis that increased copy number is a specific association with Duffy-negativity, although the number of Duffy-negatives was small and further sampling is required to test this association thoroughly.

Author summary

Plasmodium vivax invasion of human erythrocytes relies on interaction between the Duffy antigen and P. vivax Duffy Binding Protein (PvDBP). Whole genome sequences from P. vivax field isolates in Madagascar identified a duplication of the PvDBP gene and PvDBP duplication has also been detected in non-African P. vivax-endemic countries.

Two types of PvDBP duplications have been reported, termed Cambodian and Malagasy-type duplications. Our study used a combination of PCR-based diagnostic method, a novel quantitative real-time PCR assay, and whole genome sequencing to determine the prevalence and type of PvDBP duplications, as well as PvDBP copy number on a broad number of P. vivax samples in Ethiopia. We found that over 65% of P. vivax isolated from the symptomatic infections were detected with PvDBP duplications and PvDBP varied from 1 to >4 copies. The majority of PvDBP duplications belongs to the Cambodian-type while the Malagasy-type duplications was also detected. For the asymptomatic infections, despite a small sample size, the majority of P. vivax were detected with a single-copy based on both PCR and qPCR assays. There was no significant difference in PvDBP copy number between Duffy-null heterozygote and Duffy-positive homozygote/heterozygote. Further investigation is needed with expanded Duffy-null homozygotes to examine the functional significance of PvDBP expansion.
Design and performance of bending-magnet beamline BL02B at the SSRF
Authors: Meng Xiangyu , Guo Zhi , Wang Yong , Zhang Hui , Han Yong , Zhao Gaofeng , Liu Zhi , Tai Renzhong
Published: February 2019

The BL02B bending-magnet beamline at the Shanghai Synchrotron Radiation Facility (SSRF) has been constructed and is now operational for ambient-pressure photoelectron spectroscopy (APPES) and photon-in/photon-out spectroscopy (PIPOS) experimental use. Optical optimization was implemented for realization of high performance, e.g. photon flux, energy-resolving power and focus spot size. X-ray photoelectron spectroscopy experiments show that the energy range extends from 40 to 2000 eV. Argon, nitrogen and neon gas core-shell excitation spectra indicate energy-resolving powers of over 1.4 × 104 @ 244 eV, 1.0 × 104 @ 401 eV and 7.0 × 103 @ 867 eV, respectively. The measured photon flux is 1.3 × 1011 photons s−1 @ E/ΔE = 3700 at 244 eV at the expected sample position, for the SSRF electron energy of 3.5 GeV and electron current of 240 mA. The spot sizes are 177 µm × 23 µm and 150 µm × 46 µm at the APPES and PIPOS samples, respectively.
Lean business models change process in digital entrepreneurship
Authors: Balocco Raffaello , Cavallo Angelo , Ghezzi Antonio , Berbegal-Mirabent Jasmina
Published: February 2019

Purpose

Business model change (BMC) is a process new ventures are frequently involved in, especially in dynamic environments like the digital industry: copying with it is a key issue for entrepreneurs attempting to shorten the transition between current and new business models (BMs) and avoid losses in terms of revenue, image and customer retention, while acquiring experience and validated learning in the process. The purpose of this paper is to propose a lean framework to support digital new ventures in the BMC process.

Design/methodology/approach

The study builds its contribution on two pillars: a review on BM and the lean thinking theories, and a multiple case study on three digital new ventures which underwent BMC.

Findings

The study shows how BMC in a digital context can beneficially follow lean principles, and how these principles can be integrated in an original lean framework to experiment on, validate and subsequently change a BM.

Originality/value

The authors provide the “single minute exchange of die” for BMC framework that extends and complements lean startup approaches to further relate lean thinking and BMC, thus operationalizing the process of BM experimenting and validation that enables change.
Does cultural intelligence increase work engagement? The role of idiocentrism-allocentrism and organizational culture in MNCs
Authors: Gabel-Shemueli Rachel , Westman Mina , Chen Shoshi , Bahamonde Danae
Published: February 2019

Purpose

The purpose of this paper is to examine the effects of cultural intelligence (CQ), idiocentrism-allocentrism and organizational culture on work engagement in a multinational organization from the perspective of conservation of resources theory.

Design/methodology/approach

The sample consisted of 219 employees of a multinational company (MNC). Partial least squares–structural equation modeling was used to test the research model.

Findings

The results suggest that CQ is positively related to work engagement and that this relationship is moderated by employees’ idiocentrism-allocentrism, as well as by the adaptability dimension of organizational culture.

Research limitations/implications

Greater generalizability of the findings could be achieved with a more geographically dispersed sample. Other cultural dimensions, as well as personal and organizational characteristics, should be considered in order to more clearly ascertain the relationships between these variables.

Practical implications

The findings suggest that CQ is a powerful tool for developing employee engagement within MNCs. Furthermore, a highly adaptive organizational culture and consideration of employees’ cultural values are important in order to enhance the effect of CQ on engagement.

Originality/value

This study identifies relevant resources that can aid in managing a diverse workforce and increasing employee engagement in companies that operate across national borders.
Parallelization and analysis of selected numerical algorithms using OpenMP and Pluto on symmetric multiprocessing machine
Authors: Sardar Tanvir Habib , Faizabadi Ahmed Rimaz
Published: February 2019

Purpose

In recent years, there is a gradual shift from sequential computing to parallel computing. Nowadays, nearly all computers are of multicore processors. To exploit the available cores, parallel computing becomes necessary. It increases speed by processing huge amount of data in real time. The purpose of this paper is to parallelize a set of well-known programs using different techniques to determine best way to parallelize a program experimented.

Design/methodology/approach

A set of numeric algorithms are parallelized using hand parallelization using OpenMP and auto parallelization using Pluto tool.

Findings

The work discovers that few of the algorithms are well suited in auto parallelization using Pluto tool but many of the algorithms execute more efficiently using OpenMP hand parallelization.

Originality/value

The work provides an original work on parallelization using OpenMP programming paradigm and Pluto tool.
Quantification of free convection within a hemispherical annulus through a porous medium saturated by water-copper nanofluid
Authors: Baïri Abderrahmane , Suresh Nagaraj , Gayathri Palanisamy , Nithyadevi Nagarajan , Abimanyu Purusothaman
Published: February 2019

Purpose

A porous medium saturated with a nanofluid based on pure water and copper nanoparticles is used for cooling a hemispherical electronic device contained in an annulus space. The disc of the cavity could be inclined at an angle ranging from 0 ° (horizontal disc with dome facing upwards) to 180° (horizontal disc with dome facing downwards). The important surface heat flux generated by the dome leads to high Rayleigh number values reaching 7.29 × 10^10. The purpose of this work is to examine the influence of the nanofluid saturated porous medium on the free convective heat transfer.

Design/methodology/approach

Heat transfer occurring between this active component and the isothermal passive cupola is quantified by means of a three-dimensional numerical study using the control volume method associated to the SIMPLE algorithm.

Findings

The work shows that heat transfer in the annulus space is improved by interposing a porous medium saturated with the water-copper nanofluid.

Originality/value

New correlation is proposed to calculate the Nusselt number for any combination of the inclination angle, the fraction volume, the Rayleigh number and the ratio between the thermal conductivities of the porous medium and the fluid. The wide ranges corresponding to these parameters allow the thermal design of this electronic equipment for various configurations.
A review of security assessment methodologies in industrial control systems
Authors: Qassim Qais Saif , Jamil Norziana , Daud Maslina , Patel Ahmed , Ja’affar Norhamadi
Published: February 2019

Purpose

The common implementation practices of modern industrial control systems (ICS) has left a window wide open to various security vulnerabilities. As the cyber-threat landscape continues to evolve, the ICS and their underlying architecture must be protected to withstand cyber-attacks. This study aims to review several ICS security assessment methodologies to identify an appropriate vulnerability assessment method for the ICS systems that examine both critical physical and cyber systems so as to protect the national critical infrastructure.

Design/methodology/approach

This paper reviews several ICS security assessment methodologies and explores whether the existing methodologies are indeed sufficient to meet the cyber security assessment exercise required to validate the security of electrical power control systems.

Findings

The study showed that most of the examined methodologies seem to concentrate on vulnerability identification and prioritisation techniques, whilst other security techniques received noticeably less attention. The study also showed that the least attention is devoted to patch management process due to the critical nature of the SCADA system. Additionally, this review portrayed that only two security assessment methodologies exhibited absolute fulfilment of all NERC-CIP security requirements, whilst the others only partially fulfilled the essential requirements.

Originality/value

This paper presents a review and a comparative analysis of several standard SCADA security assessment methodologies and guidelines published by internationally recognised bodies. In addition, it explores the adequacy of the existing methodologies in meeting cyber security assessment practices required for electrical power networks.
Integrated reliability and maintainability analysis of Computerized Numerical Control Turning Center considering the effects of human and organizational factors
Authors: Patil Rajkumar Bhimgonda
Published: February 2019

Purpose

Reliability, maintainability and availability of modern complex engineered systems are significantly affected by four basic systems or elements: hardware, software, organizational and human. Computerized Numerical Control Turning Center (CNCTC) is one of the complex machine tools used in manufacturing industries. Several research studies have shown that the reliability and maintainability is greatly influenced by human and organizational factors (HOFs). The purpose of this paper is to identify critical HOFs and their effects on the reliability and maintainability of the CNCTC.

Design/methodology/approach

In this paper, 12 human performance influencing factors (PIFs) and 10 organizational factors (OFs) which affect the reliability and maintainability of the CNCTC are identified and prioritized according to their criticality. The opinions of experts in the fields are used for prioritizing, whereas the field failure and repair data are used for reliability and maintainability modeling.

Findings

Experience, training, and behavior are the three most critical human PIFs, and safety culture, problem solving resources, corrective action program and training program are the four most critical OFs which significantly affect the reliability and maintainability of the CNCTC. The reliability and maintainability analysis reveals that the Weibull is the best-fit distribution for time-between-failure data, whereas log-normal is the best-fit distribution for Time-To-Repair data. The failure rate of the CNCTC is nearly constant. Nearly 66 percent of the total failures and repairs are typically due to the hardware system. The percentage of failures and repairs influenced by HOFs is nearly only 16 percent; however, the failure and repair impact of HOFs is significant. The HOFs can increase the mean-time-to-repair and mean-time-between-failure of the CNCTC by nearly 65 and 33 percent, respectively.

Originality/value

The paper uses the field failure data and expert opinions for the analysis. The critical sub-systems of the CNCTC are identified using the judgment of the experts, and the trend of the results is verified with published results.
Traci Lynn Jewelry: an entrepreneur maximizing shining opportunities
Authors: Glackin Caroline E.
Published: February 2019

Theoretical basis

The central issue in the case is opportunity identification and decision making. While the literature on direct selling is limited, much has been written about ideation, effectuation, causality and opportunity identification and assessment. Scholars of entrepreneurship debate whether entrepreneurial opportunities are identified and assessed primarily through effectuation or causation.

Research methodology

This case is based upon a combination of interviews with the protagonist, her staff and secondary research.

Case overview/synopsis

This case explores the opportunity identification, assessment and decision making of an energetic, African American, female founder and CEO in the rarely-researched direct selling channel. Dr Traci Lynn Burton founded her company at 24 with an investment of $200. In 2008, in its second incarnation, Traci Lynn Jewelry became a direct selling company and has taken bold steps. By 2018, the company was a direct selling leader and was preparing to launch a new product line. The case supports undergraduate students in understanding effectuation and causation, opportunity identification and assessment, and direct selling.

Complexity academic level

This case is primarily for upper division undergraduates. It is suitable for courses in entrepreneurial strategy, entrepreneurial marketing, general entrepreneurship emphasizing opportunity identification, opportunity assessment and/or effectuation.
Mitigating the effects of sand dunes on seismic data from the Rub al Khali basin, Saudi Arabia
Authors: Al‐Marzooq Mustafa , Diallo Mamadou S. , Etienne Vincent , Tonellot Thierry , Kaka SanLinn I.
Published: February 2019

The Rub Al Khali region in Saudi Arabia is characterized by the presence of sand dunes separated by salt flats, also called Sabkhas. In general, the elevation of dunes in this region varies between 90 and 250 m above sea level. The presence of these sand dunes, along with the rapidly changing surface topography poses challenges for seismic data acquisition and processing. The high contrast in acoustic impedance between the dune base and the underlying formation often results in amplification of seismic waves that are recorded at stations located on the surface of sand dunes. Attempts to address the issue using conventional surface‐consistent amplitude scaling methods without reducing these amplification effects generally fail, thus compromising the suitability of the processed data for amplitude versus offset analysis. In this study, we propose a new reference site technique to reduce the effects of sand dune amplification, enabling the production of data sets that are suitable for amplitude versus offset processing. The proposed technique uses a deterministic approach to derive surface‐consistent, frequency‐dependent de‐amplification functions for shots and stations located on the dunes only. Two‐dimensional synthetic and field data examples show that the technique significantly reduces the effects of sand dune amplification.