bluuebunny/crossref_metadata_2025 huggingface dataset:
Parallel Evolution of Key Genomic Features and Cellular Bioenergetics Across the Marine Radiation of a Bacterial Phylum
Authors: Getz Eric W. , Tithi Saima Sultana , Zhang Liqing , Aylward Frank O.
Published: April 2018

Diverse bacterial and archaeal lineages drive biogeochemical cycles in the global ocean, but the evolutionary processes that have shaped their genomic properties and physiological capabilities remain obscure. Here we track the genome evolution of the globally-abundant marine bacterial phylum Marinimicrobia across its diversification into modern marine environments and demonstrate that extant lineages have repeatedly switched between epipelagic and mesopelagic habitats. Moreover, we show that these habitat transitions have been accompanied by repeated and fundamental shifts in genomic organization, cellular bioenergetics, and metabolic modalities. Lineages present in epipelagic niches independently acquired genes necessary for phototrophy and environmental stress mitigation, and their genomes convergently evolved key features associated with genome streamlining. Conversely, lineages residing in mesopelagic waters independently acquired nitrate respiratory machinery and a variety of cytochromes, consistent with the use of alternative terminal electron acceptors in oxygen minimum zones (OMZs). Further, while surface water clades have retained an ancestral Na+-pumping respiratory complex, deep water lineages have largely replaced this complex with a canonical H+-pumping respiratory complex I, potentially due to the increased efficiency of the latter together with more energy-limiting environments deep in the ocean’s interior. These parallel evolutionary trends across disparate clades suggest that the evolution of key features of genomic organization and cellular bioenergetics in abundant marine lineages may in some ways be predictable and driven largely by environmental conditions and nutrient dynamics.
Genome-wide CRISPR-Cas9 screen in E. coli identifies design rules for efficient targeting
Authors: Gutierrez Belen , Ng Jérôme Wong , Cui Lun , Becavin Christophe , Bikard David
Published: April 2018

The main outcome of efficient CRISPR-Cas9 cleavage in the chromosome of bacteria is cell death. This can be conveniently used to eliminate specific genotypes from a mixed population of bacteria, which can be achieved both in vitro, e.g. to select mutants, or in vivo as an antimicrobial strategy. The efficiency with which Cas9 kills bacteria has been observed to be quite variable depending on the specific target sequence, but little is known about the sequence determinants and mechanisms involved. Here we performed a genome-wide screen of Cas9 cleavage in the chromosome of E. coli to determine the efficiency with which each guide RNA kills the cell. Surprisingly we observed a large-scale pattern where guides targeting some regions of the chromosome are more rapidly depleted than others. Unexpectedly, this pattern arises from the influence of degrading specific chromosomal regions on the copy number of the plasmid carrying the guide RNA library. After taking this effect into account, it is possible to train a neural network to predict Cas9 efficiency based on the target sequence. We show that our model learns different features than previous models trained on Eukaryotic CRISPR-Cas9 knockout libraries. Our results highlight the need for specific models to design efficient CRISPR-Cas9 tools in bacteria.
Genetic Determinants of Telomere Length in African American Youth
Authors: Zeiger Andrew M. , White Marquitta J. , Oh Sam S. , Witonsky Jonathan , Contreras Maria G. , Goddard Pagé C. , Lee Eunice Y. , Keys Kevin L. , Samedy Lesly-Anne , Liberto Jennifer R. , Mak Angel C.Y. , Magaña Joaquín , Risse-Adams Oona , Eng Celeste , Hu Donglei , Huntsman Scott , Salazar Sandra , Davis Adam , Meade Kelley , Brigino-Buenaventura Emerita , LeNoir Michael A. , Farber Harold J. , Bibbins-Domingo Kirsten , Borrell Luisa N. , Burchard Esteban G.
Published: April 2018

Telomere length (TL) is associated with numerous disease states and is affected by genetic and environmental factors. However, TL has been mostly studied in adult populations of European or Asian ancestry. These studies have identified 34 TL-associated genetic variants recently used as genetic proxies for TL. The generalizability of these associations to pediatric populations and racially diverse populations, specifically of African ancestry, remains unclear. Furthermore, six novel variants associated with TL in a population of European children have been identified but not validated. We measured TL from whole blood samples of 492 healthy African American youth (children and adolescents between 8 and 20 years old) and performed the first genome-wide association study of TL in this population. We were unable to replicate neither the 34 reported genetic associations found in adults nor the six genetic associations found in European children. However, we discovered a novel genome-wide significant association between TL and rs1483898 on chromosome 14. Our results underscore the importance of examining these genetic associations with TL in diverse pediatric populations such as African Americans.
Identifying Gene Expression Programs of Cell-type Identity and Cellular Activity with Single-Cell RNA-Seq
Authors: Kotliar Dylan , Veres Adrian , Nagy M. Aurel , Tabrizi Shervin , Hodis Eran , Melton Douglas A. , Sabeti Pardis C.
Published: April 2018

Identifying gene expression programs underlying both cell-type identity and cellular activities (e.g. life-cycle processes, responses to environmental cues) is crucial for understanding the organization of cells and tissues. Although single-cell RNA-Seq (scRNA-Seq) can quantify transcripts in individual cells, each cell’s expression profile may be a mixture of both types of programs, making them difficult to disentangle. Here we illustrate and enhance the use of matrix factorization as a solution to this problem. We show with simulations that a method that we call consensus non-negative matrix factorization (cNMF) accurately infers identity and activity programs, including the relative contribution of programs in each cell. Applied to published brain organoid and visual cortex scRNA-Seq datasets, cNMF refines the hierarchy of cell types and identifies both expected (e.g. cell cycle and hypoxia) and intriguing novel activity programs. We propose that one of the novel programs may reflect a neurosecretory phenotype and a second may underlie the formation of neuronal synapses. We make cNMF available to the community and illustrate how this approach can provide key insights into gene expression variation within and between cell types.
Inter-annual variation in seasonal dengue epidemics driven by multiple interacting factors in Guangzhou, China
Authors: Oidtman Rachel J. , Lai Shengjie , Huang Zhoujie , Yang Juan , Siraj Amir S. , Reiner Robert C. , Tatem Andrew J. , Alex Perkins T. , Yu Hongjie
Published: April 2018

Vector-borne diseases display wide inter-annual variation in seasonal epidemic size due to their complex dependence on temporally variable environmental conditions and other factors. In 2014, Guangzhou, China experienced its worst dengue epidemic on record, with incidence exceeding the historical average by two orders of magnitude. To disentangle contributions from multiple factors to inter-annual variation in epidemic size, we fitted a semi-mechanistic model to time series data from 2005-2015 and performed a series of factorial simulation experiments in which seasonal epidemics were simulated under all combinations of year-specific patterns of four time-varying factors: imported cases, mosquito density, temperature, and residual variation in local conditions not explicitly represented in the model. Our results indicate that while epidemics in most years were limited by unfavorable conditions with respect to one or more factors, the epidemic in 2014 was made possible by the combination of favorable conditions for all factors considered in our analysis.
Structurally Constrained Effective Brain Connectivity
Authors: Crimi Alessandro , Dodero Luca , Sambataro Fabio , Murino Vittorio , Sona Diego
Published: April 2018

The relationship between structure and function is of interest in many research fields involving the study of complex biological processes. In neuroscience in particular, the fusion of structural and functional data can help understanding the underlying principles of the operational networks in the brain. To address this issue, this paper proposes a constrained autoregressive model leading to a representation of “effective” connectivity that can be used to better understand how the structure modulates the function. Or simply, it can be used to find novel biomarkers characterizing groups of subjects. In practice, an initial structural connectivity representation is re-weighted to explain the functional co-activations. This is obtained by minimizing the reconstruction error of an autoregressive model constrained by the structural connectivity prior. The model has been designed to also include indirect connections, allowing to split direct and indirect components in the functional connectivity, and it can be used with raw and deconvoluted BOLD signal.

The derived representation of dependencies was compared to the well known dynamic causal model, giving results closer to known ground-truth. Further evaluation of the proposed effective network was performed on two typical tasks. In a first experiment the direct functional dependencies were tested on a community detection problem, where the brain was partitioned using the effective networks across multiple subjects. In a second experiment the model was validated in a case-control task, which aimed at differentiating healthy subjects from individuals with autism spectrum disorder. Results showed that using effective connectivity leads to clusters better describing the functional interactions in the community detection task, while maintaining the original structural organization, and obtaining a better discrimination in the case-control classification task.

Highlights

A method to combine structural and functional connectivity by using autoregressive model is proposed.

The autoregressive model is constrained by structural connectivity defining coefficients for Granger causality.

The usefulness of the generated effective connections is tested on simulations, ground-truth default mode network experiments, a classification and clustering task.

The method can be used for direct and indirect connections, and with raw and deconvoluted BOLD signal.
Cerebellar nuclei neurons dictate cortical growth through developmental scaling of presynaptic Purkinje cells
Authors: Willett Ryan T. , Wojcinski Alexandre , Bayin N. Sumru , Lao Zhimin , Stephen Daniel , Dauber-Decker Katherine L. , Wu Zhuhao , Tessier-Lavigne Marc , Saito Hiromitsu , Suzuki Noboru , Joyner Alexandra L.
Published: April 2018

Efficient function of neural systems requires the production of specific cell types in the correct proportions. Here we report that reduction of the earliest born neurons of the cerebellum, excitatory cerebellar nuclei neurons (eCN), results in a subsequent reduction in growth of the cerebellar cortex due to an accompanying loss of their presynaptic target Purkinje cells. Conditional knockout of the homeobox genesEn1andEn2(En1/2) in the rhombic lip-derived eCN and granule cell precursors leads to embryonic loss of a subset of medial eCN and cell non-autonomous and location specific loss of Purkinje cells, with subsequent proportional scaling down of cortex growth. We propose that subsets of eCN dictate the survival of their specific Purkinje cell partners, and in turn sonic hedgehog secreted by Purkinje cells scales the expansion of granule cells and interneurons to produce functional local circuits and the proper folded morphology of the cerebellum.
Physical activity predicts population-level age-related differences in frontal white matter
Authors: Strömmer Juho M. , Davis Simon W. , Henson Richard N. , Tyler Lorraine K. ,   Cam-CAN, Campbell Karen L.
Published: April 2018

Physical activity has positive effects on brain health and cognitive function throughout the lifespan. Thus far, few studies have examined the effects of physical activity on white matter (WM) microstructure and psychomotor speed within the same, population-based sample (critical if conclusions are to extend to the wider population). Here, using diffusion tensor imaging and a simple reaction time task within a relatively large population-derived sample (N = 399; 18–87 years) from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN), we demonstrate that physical activity mediates the effect of age on white matter integrity, measured with fractional anisotropy. Higher self-reported daily physical activity was associated with greater preservation of WM in several frontal tracts, including the genu of corpus callosum, uncinate fasciculus, external capsule and anterior limb of the internal capsule. We also show that the age-related slowing is mediated by WM integrity in the genu. Our findings contribute to a growing body of work suggesting that a physically active lifestyle may protect against age-related structural disconnection and slowing.
N-1-naphthylphthalamic acid stimulates tomato hypocotyl elongation, elevates ethylene levels and alters metabolic homeostasis
Authors: Nongmaithem Sapana , Devulapalli Sameera , Sreelakshmi Yellamaraju , Sharma Rameshwar
Published: April 2018

One sentence summary

N-1-naphthylphthalamic acid (NPA) treatment stimulates tomato hypocotyl elongation likely by elevating ethylene emission and lowering indole-3-butyric acid levels in the seedlings.

In higher plants, phytohormone indole-3-acetic acid is characteristically transported from the apex towards the base of the plant, termed as polar auxin transport (PAT). Among the inhibitors blocking PAT, N-1-naphthylphthalamic acid (NPA) that targets ABCB transporters is most commonly used. NPA-treated light-grown Arabidopsis seedlings show severe inhibition of hypocotyl and root elongation. In light-grown tomato seedlings, NPA inhibited root growth, but contrary to Arabidopsis stimulated hypocotyl elongation. The NPA-stimulation of hypocotyl elongation was milder in blue, red, and far-red light-grown seedlings. The NPA-treatment stimulated emission of ethylene from the seedlings. The scrubbing of ethylene by mercuric perchlorate reduced NPA-stimulated hypocotyl elongation. NPA action on hypocotyl elongation was antagonized by 1-methylcyclopropene, an inhibitor of ethylene action. NPA-treated seedlings had reduced levels of indole-3-butyric acid and higher levels of zeatin in the shoots. NPA did not alter indole-3-acetic levels in shoots. The analysis of metabolic networks indicated that NPA-treatment induced moderate shifts in the networks compared to exogenous ethylene that induced a drastic shift in metabolic networks. Our results indicate that in addition to ethylene, NPA-stimulated hypocotyl elongation in tomato may also involve zeatin and indole-3-butyric acid. Our results indicate that NPA-mediated physiological responses may vary in a species-specific fashion.
Causal gene regulatory network inference using enhancer activity as a causal anchor
Authors: Vipin Deepti , Wang Lingfei , Devailly Guillaume , Michoel Tom , Joshi Anagha
Published: May 2018

Motivation

Transcription control plays a crucial role in establishing a unique gene expression signature for each of the hundreds of mammalian cell types. Though gene expression data has been widely used to infer the cellular regulatory networks, the methods mainly infer correlations rather than causality. We propose that a causal inference framework successfully used for eQTL data can be extended to infer causal regulatory networks using enhancers as causal anchors and enhancer RNA expression as a readout of enhancer activity.

Results

We developed statistical models and likelihood-ratio tests to infer causal gene regulatory networks using enhancer RNA (eRNA) expression information as a causal anchor and applied the framework to eRNA and transcript expression data from the FANTOM consortium. Predicted causal targets of transcription factors (TFs) in mouse embryonic stem cells, macrophages and erythroblastic leukemia overlapped significantly with experimentally validated targets from ChIP-seq and perturbation data. We further improved the model by taking into account that some TFs might act in a quantitative, dosage-dependent manner, whereas others might act predominantly in a binary on/off fashion. We predicted TF targets from concerted variation of eRNA and TF and target promoter expression levels within a single cell type as well as across multiple cell types. Importantly, TFs with high-confidence predictions were largely different between these two analyses, demonstrating that variability within a cell type is highly relevant for target prediction of cell type specific factors. Finally, we generated a compendium of high-confidence TF targets across diverse human cell and tissue types.

Availability

Methods have been implemented in the Findr software, available at https://github.com/lingfeiwang/findr

Contact

Tom.Michoel@roslin.ed.ac.uk, Anagha.Joshi@roslin.ed.ac.uk
Structural insights into the binding mechanism of Plasmodium falciparum exported Hsp40-Hsp70 chaperone pair
Authors: Behl Ankita , Mishra Prakash Chandra
Published: April 2018

Expression of heat shock proteins in Plasmodium falciparum (Pf) increases during febrile episodes to play key roles in several necessary cellular processes. PFA0660w-PfHsp70-x, an exported chaperone pair is known to co-localize to specialized intracellular structures termed J-dots, and has been implicated in trafficking of the major virulence factor, PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1) across the host cell. This article highlights for the first time detailed structural analysis of PFA0660w-PfHsp70-x chaperone pair to better understand their binding mechanism. Here, we have modeled reliable molecular structures for the complete conserved region of PFA0660w and PfHsp70-x. These structures were evaluated by different structure verification tools followed by molecular dynamics (MD) simulations. The model of PFA0660w was subjected to docking with PfHsp70-x using Haddock to reveal a number of residues crucial for their bipartite interaction, and also performed MD simulations on the complex. The peptide binding clefts of PFA0660w and its other Plasmodium species homologs were found to be bigger than their counterparts in higher eukaryotes like yeast, humans and C. parvum. Based on our results, we propose a model for PFA0660w-PfHsp70-x interaction and a mechanism of substrate binding, and compare it with its dimeric human counterparts. Owing to these striking structural differences between the host and parasite chaperones, such information on the essential Hsp40 and its partner Hsp70 may form the basis for rational drug design against fatal malaria.
HOPS: a quantitative score reveals pervasive horizontal pleiotropy in human genetic variation is driven by extreme polygenicity of human traits and diseases
Authors: Jordan Daniel M. , Verbanck Marie , Do Ron
Published: April 2018

Horizontal pleiotropy, where one variant has independent effects on multiple traits, is important for our understanding of the genetic architecture of human phenotypes. We develop a method to quantify horizontal pleiotropy using genome-wide association summary statistics and apply it to 372 heritable phenotypes measured in 361,194 UK Biobank individuals. Horizontal pleiotropy is pervasive throughout the human genome, prominent among highly polygenic phenotypes, and enriched in active regulatory regions. Our results highlight the central role horizontal pleiotropy plays in the genetic architecture of human phenotypes. The HOrizontal Pleiotropy Score (HOPS) method is available on Github at https://github.com/rondolab/HOPS.
The utility of Saw-scaled viper,Echis pyramidum, and Kenyan sand boa,Eryx colubrinusas bioindicator of heavy metals bioaccumulation in relation to DPTA soil extract and biological consequences
Authors: Sleem Doha M. M. , Kadry Mohamed A. M. , Mohallal Eman M. E. , Marie Mohamed A. S.
Published: April 2018

The present investigation was conducted to compare between the ecotoxocological effects of Ca, Mg, Fe, Cu, Zn, Co, Mo, Mn, B, Al, Sr, Pb, Ni, Cd and Cr on the saw-scaled viper,Echis pyramidum (E. p.)and the Kenyan sand boa,Eryx colubrinus(E.c.) inhabiting Gabal El-Nagar and Kahk Qibliyyah respectively in El-Faiyum desert, Egypt. Accumulation varied significantly among the liver, kidney and muscle. The relationship between concentrations of heavy metals in snakes and those in the soil from the collected sites was established by analyzing metal DPTA in soil. Bioaccumulation factor is calculated to estimate the degree of toxicity within the tissues. Morphometric analysis was recorded. All body morphometric measurements were higher inE. p. than inE. c.. Body, liver, gonad, kidney and heart weight, HSI, GSI, RBCs count, Hb content, PCV, MCV, MCH, MCHC, plasma glucose, total lipids and total proteins showed a significant increase inE. p. Histopathological examination showed damage and alterations of liver, kidney and testes sections. The tissues ofE. c. were more destructed than those ofE. p..
Reconstitution of immune cell interactions in free-standing membranes
Authors: Jenkins Edward , Santos Ana Mafalda , Felce James H. , Hatherley Deborah , Dustin Michael L. , Davis Simon J. , Eggeling Christian , Sezgin Erdinc
Published: April 2018

The spatiotemporal regulation of signalling proteins at the contacts formed between immune cells and their targets determines how and when immune responses begin and end. It is important, therefore, to be able to elucidate molecular processes occurring at these interfaces. However, the detailed investigation of each component’s contribution to the formation and regulation of the contact is hampered by the complexity of cellular composition and architecture. Moreover, the transient nature of these interactions creates additional challenges, especially for using advanced imaging technology. One approach to circumventing these problems is to establishin vitrosystems that faithfully mimic immune cell interactions, incorporating complexity that can be ‘dialled-in’ as needed. Here, we present anin vitrosystem making use of synthetic vesicles that mimic important aspects of immune cell surfaces. Using this system, we begin to investigate the spatial distribution of signalling molecules (receptors, kinases and phosphatases) and the intracellular rearrangements that accompany the initiation of signalling in T cells. The model system presented here is expected to be widely applicable.

Summary Statement

Immune cell-cell interactions are reconstituted in free-standing vesicles wherein spatiotemporal aspects of immune synapse formation can be investigated.
Adult-born neurons maintain hippocampal cholinergic inputs and support working memory during aging
Authors: Kirshenbaum Greer S. , Robson Victoria K. , Shansky Rebecca M. , Savage Lisa M. , Leonardo E. David , Dranovsky Alex
Published: April 2018

Adult neurogenesis is impaired in disorders of stress, memory, and cognition though its normal function remains unclear. Moreover, a systems level understanding of how a small number of young hippocampal neurons could dramatically influence brain function is lacking. We examined whether adult neurogenesis sustains hippocampal connections across the life span. Long-term suppression of neurogenesis as occurs during stress and aging resulted in a progressing decline in hippocampal acetylcholine and the slow emergence of profound working memory deficits. These deficits were accompanied by compensatory rewiring of cholinergic dentate gyrus inputs such that ventrally projecting neurons were recruited by the dorsal projection. Our study demonstrates that hippocampal neurogenesis supports memory by maintaining the septohippocampal circuit across the lifespan. It also provides a systems level explanation for the progressive nature of memory deterioration during normal and pathological aging and indicates that the brain connectome is malleable by experience.
Changes in the gut microbiota and fermentation products associated with enhanced longevity in acarbose-treated mice
Authors: Smith Byron J , Miller Richard A , Ericsson Aaron C , Harrison David C , Strong Randy , Schmidt Thomas M
Published: April 2018

Background

Treatment with theα-glucosidase inhibitor acarbose increases median lifespan by approximately 20% in male mice and 5% in females. This longevity extension differs from dietary restriction based on a number of features, including the relatively small effects on weight and the sex-specificity of the lifespan effect. By inhibiting host digestion, acarbose increases the flux of starch to the lower digestive system, resulting in changes to the gut microbiota and their fermentation products. Given the documented health benefits of short-chain fatty acids (SCFAs), the dominant products of starch fermentation by gut bacteria, this secondary effect of acarbose could contribute to increased longevity in mice. To explore this hypothesis, we compared the fecal microbiome of mice treated with acarbose to control mice at three independent study sites.

Results

Microbial communities and the concentrations of SCFAs in the feces of mice treated with acarbose were notably different from those of control mice. At all three study sites, the bloom of a single bacterial taxon was the most obvious response to acarbose treatment. The blooming populations were classified to the largely unculturedBacteroidalesfamilyMuribaculaceaeand were the same taxonomic unit at two of the three sites. Total SCFA concentrations in feces were increased in treated mice, with increased butyrate and propionate in particular. Across all samples,Muribaculaceaeabundance was strongly correlated with propionate and community composition was an important predictor of SCFA concentrations. Cox proportional hazards regression showed that the fecal concentrations of acetate, butyrate, and propionate were, together, predictive of mouse longevity even while controlling for sex, site, and acarbose.

Conclusion

We have demonstrated a correlation between fecal SCFAs and lifespan in mice, suggesting a role of the gut microbiota in the longevity-enhancing properties of acarbose. Treatment modulated the taxonomic composition and fermentation products of the gut microbiome, while the site-dependence of the microbiota illustrates the challenges facing reproducibility and interpretation in microbiome studies. These results motivate future studies exploring manipulation of the gut microbial community and its fermentation products for increased longevity, and to test a causal role of SCFAs in the observed effects of acarbose.
Connectomics of the zebrafish’s lateral-line neuromast reveals wiring and miswiring in a simple microcircuit
Authors: Dow Eliot , Jacobo Adrian , Hossain Sajjad , Siletti Kimberly , Hudspeth A. J.
Published: April 2018

The lateral-line neuromast of the zebrafish displays a restricted, consistent pattern of innervation that facilitates the comparison of microcircuits across individuals, developmental stages, and genotypes. We used serial blockface scanning electron microscopy to determine from multiple specimens the neuromast connectome, or comprehensive set of connections between hair cells and afferent and efferent nerve fibers. This analysis delineated a complex but consistent wiring pattern with three striking characteristics: each nerve terminal is highly specific in receiving innervation from hair cells of a single directional sensitivity; the innervation is redundant; and the terminals manifest a hierarchy of dominance. Mutation of the canonical planar-cell-polarity genevangl2, which decouples the asymmetric phenotypes of sibling hair-cell pairs, results in randomly positioned, randomly oriented sibling cells that nonetheless retain specific wiring. Because larvae that overexpress Notch exhibit uniformly oriented, uniformly innervating hair-cell siblings, wiring specificity is mediated by the Notch signaling pathway.
The impact of a governmental cash transfer programme on tuberculosis cure rate in Brazil: A quasi-experimental approach
Authors: Carter Daniel J. , Daniel Rhian , Torrens Ana W. , Sanchez Mauro N. , Maciel Ethel L. N. , Bartholomay Patricia , Barreira Draurio C. , Rasella Davide , Barreto Maurício L. , Rodrigues Laura C. , Boccia Delia
Published: April 2018

Background

Social vulnerability is strongly associated with tuberculosis (TB) indicators like cure rate. By addressing key social determinants, social protection policies such as Brazil’s Bolsa Família Programme (BFP), a governmental conditional cash transfer, may play a role in TB control. Evidence is consolidating around a positive effect of social protection on TB outcomes, however methodological limitations prevent strong conclusions. This paper uses a quasi-experimental approach to more rigorously evaluate the effect of BFP on TB cure rate.

Methods & Findings

The data source was Brazil’s TB notification system (SINAN), linked to the national registry of those in poverty (CadUnico) and the BFP payroll. Propensity scores (PSs) were estimated from a complete-case logistic regression using covariates from this linked dataset, informed by a directed acyclic graph. Control patients were matched to exposed patients on the PS and the average effect of treatment on the treated (ATT) was estimated as the difference in TB cure rate between matched groups (n = 2167). The ATT was estimated as 10·58 (95% CIs: 4·39, 16·77). This suggests that 10·58% of the TB patients receiving BFP who were cured would not have been cured had they not received BFP. The direction of this effect was robust to sensitivity analyses performed and the PS matching broadly improved balance, although missing data limited the sample size.

Conclusions

This work is the first quasi-experimental evaluation of social protection in wide-scale practice on TB outcomes. It demonstrates a positive effect of conditional cash transfers on TB cure rate consistent with existing work, suggesting changes to policy and future research on increasing access to social protection for TB patients who remain uncovered by the programme.
Histone deacetylase HDA19 affects cortical cell fate by interacting with SCARECROW in the Arabidopsis root
Authors: Chen WQ , Drapek C , Li DX , Xu ZH , Benfey PN , Bai SN
Published: May 2018

Abstract/Summary

The Arabidopsis root epidermis is a simple model for investigating cell fate specification and pattern formation. In addition to regulatory networks consisting of transcription factors, histone deacetylases are also involved in the cellular patterning process. Here we report HDA19 affects the root epidermal cellular pattern through regulation of cortical cell fate by interacting with SCARECROW. This work reveals two new components in cortical cell specification and uncovers a new facet of SCR function.
The role of universities for the change of a network structure in the regional business ecosystem
Authors: Kim Changone , Park Sang-Hyeok , Seol Byung-Moon
Published: May 2018

Purpose

This paper aims to focus on the changing role of universities in university–industry collaboration (UIC) for enriching the regional business ecosystem network. For this, the authors analyze “Business Clinic Day,” (BCD) a specific UIC program which provides a consulting service for firms, small- and medium-sized enterprises (SMEs) having a specific problem, by a group of facilitators. It includes consultants such as chief executive officers (CEOs), professors and heads of regional public or private service providers. This study illustrates that various types of networks are formed between consultants and problem-owners by facilitation of university after the program.

Design/methodology/approach

This study has analyzed with social network analysis how the business network was changed from clinic day program. Furthermore, the networks surrounding SMEs are extended to the other people connected to them. This means that the business network of SMEs had been diversified via the facilitation of “BCD” provided as UIC program.

Findings

Local SMEs have difficulties in enhancing their competitiveness in the market both in terms of internal resources and networks with external organizations. Thus, universities need to promote university–industry collaboration programs to enable SMEs to strengthen their competitiveness by building networks in local business ecosystems.

Originality/value

This study throws new highlights on the facilitator role of a university as a network promoter, in addition to the partner as a technology provider, in the regional business ecosystem.
Design and experimental analysis of MEMS-based Ku band phase shifter
Authors: Rajan V. Prithivi , A. Punitha
Published: April 2018

Purpose

This paper aims to design a radio frequency micro-electro-mechanical system (RF MEMS)-based phase shifter using chamfered coplanar waveguide (CPW) transmission line (t-line) with open-circuit interdigital metal–air–metal (ID MAM) capacitors.

Design/methodology/approach

The proposed phase shifter achieves maximum differential phase shift with low loss at Ku band. The phase shifter is built with one switchable fixed-fixed beam (MEMS switch) on chamfered CPW t-line in series with two planar open-circuit ID MAM capacitors. An equivalent circuit model for the proposed phase shifter is derived, and its parameters are extracted using an electromagnetic (EM) solver.

Findings

The MEMS switch is actuated using an electrostatic method with the calculated residual stress of 44.26 MPa. The fabricated phase shifter exhibits low insertion loss, close to 0.14 dB at 17 GHz, with the maximum phase shift of 15.06°. The return loss is greater than 23 dB between 12 and 18 GHz.

Originality/value

This phase shifter presents a promising solution for low loss applications in the Ku band with a maximum phase shift. As the maximum phase shift of 15.06° is achieved for a unit cell with low insertion loss, the phase shifter is found to be feasible for modern electronically tunable phased arrays used for satellite communication and radar systems.
Gender and relationship differences in the perceptions of male and female leadership
Authors: Szymanska Izabela I. , Rubin Beth A.
Published: April 2018

Purpose

This research aims to investigate the differences in evaluations of job performance between male and female managers by those managers’ immediate bosses and peers.

Design/methodology/approach

Drawing on gender structure theory, along with ideas about status characteristics, the authors use hierarchical regression to test the hypotheses that male and female bosses and peers deferentially evaluate the male and female manager’s global job performance. The authors hypothesize significant two-way interactions (gender of the manager by gender of evaluator) in predicting a manager’s job performance.

Findings

The results suggest that while male peers rate female managers’ job performance significantly lower than that of male managers, female peers do not discriminate between genders in their performance evaluations. Also, managers’ bosses were found not to discriminate between genders of their subordinates.

Research limitations/implications

The limitations of this study have to do primarily with the data. While the data are rich on some dimensions, they are weak on others, especially with regard to the detail about the jobs the respondents did, detailed level of familiarity with the evaluated managers, as well as racial background. The data also do not provide information on the different facets of job performance, the evaluation of which could potentially be impacted by managerial gender; this study is focused exclusively on global job performance.

Practical implications

The authors discuss various theoretical explanations of this pattern of results, as well as its possible influence on female managers’ careers. Although the effect size of the negative bias that male peers exhibit toward female managers is relatively small, it may be argued that lower performance assessments can accumulate over years in multiple job evaluations, negatively affecting the career of female leaders.

Originality/value

The evaluations supplied by different organizational members gain importance with the increased use of 360-degree feedback instruments not just for developmental but also for the job performance appraisal purposes. While the job evaluations of managers’ bosses have been investigated in the past with regard to the possible gender bias, this study provides the first known to the authors’, evidence. Also, this study points to a direct bias in performance assessments, rather than a potentially more subtle, non-performance-based bias that affects the disparities in wages and promotions of female managers. Thus, this study helps to fill a significant gap in the literature on organizations and it may have practical implications for the advancement of female managers. In addition to this contribution, this study also provides data that may be useful in resolving the ongoing debate whether female bosses act more as cogs in the machine or as change agents in organizations.
Self-efficacy measure may enhance your recruitment and placement efforts
Authors: Lyons Paul R. , Bandura Randall P.
Published: April 2018

Purpose

This paper aims to offer the views that the psychological construct, self-efficacy, is significantly related to high or strong performance at work and that a brief, efficient survey allows for managers and HR practitioners to assess individuals per the characteristic.

Design/methodology/approach

The authors performed a broad review of literature, mostly empirical research, focused in particular upon the linkage of self-efficacy with work performance. Important conclusions of this review are reported. Also researched were the existing measures (surveys and scales) of self-efficacy that demonstrated validity and reliability.

Findings

Hundreds of studies, in combination, have concluded that the construct, self-efficacy, is highly and positively related to individual motivation, self-confidence, proactive behavior, and work performance, among other valued characteristics. There are measures to use to assess individual beliefs regarding self-efficacy that may be used in for recruitment and placement decisions.

Originality/value

Clearly expressed is the substance and value of the self-efficacy construct which has been the subject of hundreds of studies. The importance of self-efficacy and its linkage to motivation and performance is expressed. A brief, statistically valid, and reliable instrument is offered in its entirety for use by managers and/or HR practitioners.
Reallocation of IPO shares: emerging market evidence
Authors: Wadhwa Kavita , Syamala Sudhakara Reddy
Published: May 2018

Purpose

The purpose of this paper is to study the reallocation of initial public offering (IPO) shares to retail investors, non-institutional buyers (NIBs) and qualified institutional buyers (QIBs). The authors examine how the reallocation process is related to the pricing decision of the underwriter. The authors also examine the long-run performance of the IPOs classified on the basis of the highest reallocation by retail investors, NIBs and QIBs.

Design/methodology/approach

The authors use regression analysis as well as 2SLS and three-stage least squares models to test the hypotheses. For long-run performance analysis, the authors adopt Carhart’s (1997) four-factor model.

Findings

First, the authors provide evidence that the reallocation of IPO shares for retail investors, NIBs and QIBs is frequent. Second, all three categories of investors are treated differently in the reallocation of underpriced shares. Third, the authors find that the reallocation and pricing strategies are interdependent and both the strategies are used by the underwriter to reward and favor retail investors for showing high level of demand. The authors find that in India, underwriters reward retail investors. Lastly, even though underwriters favor retail investors for reallocation, the authors find that IPOs which receive highest reallocation to retail investors perform poorly in the long run.

Originality/value

This paper is the first paper to show evidence of reallocation of IPO shares by underwriters for an emerging market. The paper is different from other papers as the regulatory regime present in the Indian markets is different from other markets.
Creating relational capital through socialization in project alliances
Authors: Aaltonen Kirsi , Turkulainen Virpi
Published: April 2018

Purpose

The purpose of this paper is to elaborate the understanding of socialization in the context of temporary operations and organizational settings, using project alliance – the most contemporary approach to the management of large and complex projects – as an example. In particular, the paper also assesses how informal and formal socialization mechanisms are used to facilitate relational capital in such a setting.

Design/methodology/approach

Data were collected by two case studies of complex infrastructure projects in a Northern European city. The analysis focuses on how socialization is managed across organizational interfaces within the alliance organization during the project tendering and development phase to create relational capital.

Findings

The findings indicate that significant emphasis is put on socialization in project alliances. However, while in the tendering phase both informal and formal socialization mechanisms are used to create relational capital; in the development phase informal socialization mechanisms are associated with higher levels of relational capital and formal socialization mechanisms are used to maintain the level of relational capital.

Originality/value

While operations and supply chain management research argues that socialization is critical to manage organizational interfaces and to create relational capital in buyer-supplier relationships, research has mainly focused on ongoing operations. This study complements the prior research by developing further insight into socialization in the context of temporary operations and organizational settings; such settings create a unique empirical context, posing different managerial challenges as the results also indicate.
Process validation: coping with three dilemmas in process-based single-case research
Authors: Andersen Poul Houman , Dubois Anna , Lind Frida
Published: May 2018

Purpose

Recent research suggests that the interest in process-based single-case studies is increasing in business-to-business (B2B) marketing. This paper aims to discuss research validity issues and dilemmas encountered by process-based single-case researchers in B2B marketing.

Design/methodology/approach

This is a methodology paper that builds on an integration of experiences, ideas and literature.

Findings

In the paper, three dilemmas are suggested that researchers need to deal with in process-based single-case research. These relate to the casing process: crafting the case, communicating the case and describing the process of the study. Furthermore, process validation is suggested as a research quality concept concerned with how these dilemmas are handled.

Research limitations implications

Based on the notion of process validation, the authors provide suggestions for how casing, as a process-based single-case approach, can be conveyed and advanced in its own right.

Practical implications

This study can be used to convey insights that can help new and experienced researchers in conducting single-case studies in B2B.

Originality/value

Coping with issues of research quality in B2B marketing is of relevance to researchers dealing with process-based single-case research and process validation issues, as well as to journal reviewers evaluating the qualities of process-based single-case research.
Green buying behavior in India: an empirical analysis
Authors: Chaudhary Richa
Published: April 2018

Purpose

Using insights from theory of planned behavior (TPB), this study aims to examine the determinants and their relative importance in predicting green buying behavior among young educated consumers in India.

Design/methodology/approach

Data are collected from 202 young Indian consumers using online questionnaire survey. Confirmatory factor analysis is used to ensure the reliability and validity of study measures in the present context. Structural equation modeling is used to test the proposed research model.

Findings

Findings confirm perceived value and willingness to pay premium as significant predictors of the green purchase intention. In turn, green purchase intention significantly influenced green buying behavior.

Practical implications

This study by advancing the understanding on the factors influencing green product purchase intention and behavior among Indian youths will help the policymakers to design policies and programs to encourage the adoption of green purchase behaviors, which in turn will help in addressing the problem of environmental sustainability, which the whole world is struggling with.

Originality/value

This study validates the importance of TPB framework in comprehending consumer green product purchase intention and behavior in a culturally different context of India. Thus, this study contributes to the green marketing literature by examining the unique combination of variables in predicting green buying behavior in an integrated framework. It also extends the TPB by demonstrating the importance of additional constructs, perceived value and willingness to pay in predicting green purchase intention and behavior among young millennials in India.
Ethical leadership and work engagement
Authors: Ahmad Israr , Gao Yongqiang
Published: April 2018

Purpose

The purpose of this paper is to investigate the mediating role of psychological empowerment in the relationship between ethical leadership and employee work engagement as well as the moderating effect of power distance orientation.

Design/methodology/approach

With a multi-wave survey, this paper uses a sample of 251 employees from the banking sector in Pakistan to test the hypotheses.

Findings

The results reveal that psychological empowerment partially mediates the relationship between ethical leadership and employee work engagement. Besides, power distance orientation mitigates the positive relationship between ethical leadership and psychological empowerment as well as the indirect effect of ethical leadership on employee work engagement via psychological empowerment.

Originality/value

This study contributes to the existing ethical leadership literature by identifying psychological empowerment as an additional mediator and power distance orientation as a boundary condition, in the relationship between ethical leadership and employee work engagement.