bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shear Wave Elastography in the Evaluation of Liver Fibrosis in Children
Authors: Tutar Onur , Beşer Ömer F. , Adaletli Ibrahim , Tunc Necmettin , Gulcu Didem , Kantarci Fatih , Mihmanli Ismail , Cokugras Fugen C. , Kutlu Tufan , Ozbay Gulsen , Erkan Tulay 
Published: February 2014

ABSTRACTBackground:Shear‐wave elastography (SWE) is a novel noninvasive method that involves application of local mechanical compression on soft tissue using focused ultrasonography and acquiring strain images that show tissue response. In this study, our goal was to assess the performance of SWE in the staging of liver fibrosis in children with chronic liver disease.Methods:The study involved measuring SWE values in the right lobe of the liver in a patient group of 76 children with chronic liver disease and a control group of 50 healthy subjects. In the patient group, the shear elastic modulus values were correlated with biopsy results according to the Brunt scoring system (F0: portal fibrosis, F1: perisinusoidal or portal/periportal fibrosis, F2: both perisinusoidal and portal/periportal fibrosis, F3: bridging fibrosis, and F4: cirrhosis). Performance of SWE in estimating liver fibrosis in children was determined based on a receiver‐operating characteristics (ROC) analysis.Results:Mean SWE values of the control group and F0 group were not statistically significantly different (P = 0.106). The mean SWE values of the F1, F2, F3, and F4 groups were higher than that of the control group (all P < 0.001). Based on kiloPascal measurement values, the area under the ROC curve was 95.2% (95% confidence interval [CI] 92.1–99.5), with a sensitivity for diagnosing liver fibrosis of 91.5%, a specificity of 94.0%, a positive predictive value of 93.1%, and a negative predictive value of 92.6%. Based on meter‐per‐second measurement values, the area under the ROC curve was 96.3% (95% CI 92.7–99.8), with a sensitivity for diagnosing liver fibrosis of 93.2%, a specificity of 94.0%, a positive predictive value of 93.2%, and a negative predictive value of 94.0%. Mean SWE values for patients with nonalcoholic steatohepatitis were higher than those in the remainder of the study group.Conclusions:Although liver fibrosis can be detected using SWE, differentiation of fibrosis stages could not be achieved. The presence of steatosis significantly increased the mean SWE values on elastography and so care should be taken when assessing children with nonalcoholic steatohepatitis.
Production of systemically circulating Hedgehog by the intestine couples nutrition to growth and development
Authors: Rodenfels Jonathan , Lavrynenko Oksana , Ayciriex Sophie , Sampaio Julio L. , Carvalho Maria , Shevchenko Andrej , Eaton Suzanne 
Published: February 2014

AbstractInDrosophilalarvae, growth and developmental timing are regulated by nutrition in a tightly coordinated fashion. The networks that couple these processes are far from understood. Here, we show that the intestine responds to nutrient availability by regulating production of a circulating lipoprotein-associated form of the signaling protein Hedgehog (Hh). Levels of circulating Hh tune the rates of growth and developmental timing in a coordinated fashion. Circulating Hh signals to the fat body to control larval growth. It regulates developmental timing by controlling ecdysteroid production in the prothoracic gland. Circulating Hh is especially important during starvation, when it is also required for mobilization of fat body triacylglycerol (TAG) stores. Thus, we demonstrate that Hh, previously known only for its local morphogenetic functions, also acts as a lipoprotein-associated endocrine hormone, coordinating the response of multiple tissues to nutrient availability.
Evolutionary rates for multivariate traits: the role of selection and genetic variation
Authors: Pitchers William , Wolf Jason B. , Tregenza Tom , Hunt John , Dworkin Ian 
Published: February 2014

SummaryA fundamental question in evolutionary biology is the relative importance of selection and genetic architecture in determining evolutionary rates. Adaptive evolution can be described by the multivariate breeders’ equation, which predicts evolutionary change for a suite of phenotypic traitsas a product of directional selection acting on them (β) and the genetic variance-covariance matrix for those traits (G). Despite being empirically challenging to estimate, there are enough published estimates ofGandβto allow for synthesis of general patterns across species. We use published estimates to test the hypotheses that there are systematic differences in the rate of evolution among trait types, and that these differences are in part due to genetic architecture. We find evidence some evidence that sexually selected traits exhibit faster rates of evolution compared to life-history or morphological traits. This difference does not appear to be related to stronger selection on sexually selected traits. Using numerous proposed approaches to quantifying the shape, size and structure ofGwe examine how these parameters relate to one another, and how they vary among taxonomic and trait groupings. Despite considerable variation, they do not explain the observed differences in evolutionary rates.
Neuroanatomical diversity of corpus callosum and brain volume in the Autism Brain Imaging Data Exchange (Abide) project
Authors: Lefebvre Aline , Beggiato Anita , Bourgeron Thomas , Toro Roberto 
Published: February 2014

ABSTRACTThe corpus callosum – the main pathway for long-distance inter-hemispheric integration in the human brain – has been frequently reported to be smaller among autistic patients compared with non-autistic controls. We conducted a meta-analysis of the literature which suggested a statistically significant difference. However, the studies included were heavily underpowered: on average only 20% power to detect differences of 0.3 standard deviations, which makes it difficult to establish the reality of such a difference. We therefore studied the size of the corpus callosum among 694 subjects (328 patients, 366 controls) from the Abide cohort. Despite having achieved 99% power to detect statistically significant differences of 0.3 standard deviations, we did not observe any. To better understand the neuroanatomical diversity of the corpus callosum, and the possible reasons for the previous findings, we analysed the relationship between its size, the size of the brain, intracranial volume and intelligence scores. The corpus callosum appeared to scale non-linearly with brain size, with large brains having a proportionally smaller corpus callosum. Additionally, intelligence scores correlated with brain volume among controls but the correlation was significantly weaker among patients. We used simulations to determine to which extent these two effects could lead to artefactual differences in corpus callosum size within populations. We observed that, were there a difference in brain volume between cases and controls, normalising corpus callosum size by brain volume would not eliminate the brain volume effect, but adding brain volume as a covariate in a linear model would. Finally, we observed that because of the weaker correlation of intelligence scores and brain volume among patients, matching populations by intelligence scores could result in a bias towards including more patients with large brain volumes, inducing an artificial difference. Overall, our results highlight the necessity for open data sharing efforts such as Abide to provide a more solid ground for the discovery of neuroimaging biomarkers, within the context of the wide human neuroanatomical diversity.
Immune stimulation reduces sleep and memory ability inDrosophila melanogaster
Authors: Mallon E. B. , Alghamdi A. , Holdbrook R. T. K. , Rosato E. 
Published: February 2014

AbstractPsychoneuroimmunology studies the increasing number of connections between neurobiology, immunology and behaviour. We establishDrosophila melanogasteras a tractable model in this field by demonstrating the effects of the immune response on two fundamental behaviours: sleep and memory ability.We used the Geneswitch system to upregulate peptidoglycan receptor protein (PGRP) expression, thereby stimulating the immune system in the absence of infection. Geneswitch was activated by feeding the steroid RU486, to the flies. We used an aversive classical conditioning paradigm to quantify memory and measures of activity to infer sleep.Immune stimulated flies exhibited reduced levels of sleep, which could not be explained by a generalised increase in waking activity. The effects on sleep were more pronounced for day compared to night sleep. Immune stimulated flies also showed a reduction in memory abilities.These are important results as they establishDrosophilaas a model for immune-neural interactions and provide a possible role for sleep in the interplay between the immune response and memory.
Fluorescent sensors for activity and regulation of the nitrate transceptor CHL1/NRT1.1 and oligopeptide transporters
Authors: Ho Cheng-Hsun , Frommer Wolf B. 
Published: February 2014

AbstractTo monitor nitrate and peptide transport activityin vivo, we converted the dual-affinity nitrate transceptor CHL1/NRT1.1/NPF6.3 and four related oligopeptide transporters PTR1, 2, 4 and 5 into fluorescence activity sensors (NiTrac1, PepTrac). Substrate addition to yeast expressing transporter fusions with yellow fluorescent protein and mCerulean triggered substrate-dependent donor quenching or resonance energy transfer. Fluorescence changes were nitrate/peptide-specific, respectively. Like CHL1, NiTrac1 had biphasic kinetics. Mutation of T101A eliminated high-affinity transport and blocked the fluorescence response to low nitrate. NiTrac was used for characterizing side chains considered important for substrate interaction, proton coupling, and regulation. We observed a striking correlation between transport activity and sensor output. Coexpression of NiTrac with known calcineurin-like proteins (CBL1, 9; CIPK23) and candidates identified in an interactome screen (CBL1, KT2, WNKinase 8) blocked NiTrac1 responses, demonstrating the suitability forin vivoanalysis of activity and regulation. The new technology is applicable in plant and medical research.
ESCRT-0 is not required for ectopic Notch activation and tumor suppression inDrosophila
Authors: Tognon Emiliana , Wollscheid Nadine , Cortese Katia , Tacchetti Carlo , Vaccari Thomas 
Published: February 2014

AbstractMultivesicular endosome (MVE) sorting depends on proteins of the Endosomal Sorting Complex Required for Transport (ESCRT) family. These are organized in four complexes (ESCRT-0, -I, -II, -III) that act in a sequential fashion to deliver ubiquitylated cargoes into the internal luminal vesicles (ILVs) of the MVE.Drosophilagenes encoding ESCRT-I, -II, -III components function in sorting signaling receptors, including Notch and the JAK/STAT signaling receptor Domeless. Loss of ESCRT-I, -II, -III inDrosophilaepithelia causes altered signaling and cell polarity, suggesting that ESCRTs genes are tumor suppressors. However, the nature of the tumor suppressive function of ESCRTs, and whether tumor suppression is linked to receptor sorting is unclear. Unexpectedly, a null mutant inHrs,encoding one of components of the ESCRT-0 complex, which acts upstream of ESCRT-I, -II, -III in MVE sorting is dispensable for tumor suppression. Here, we report that twoDrosophilaepithelia lacking activity ofStam, the other known components of the ESCRT-0 complex, or of bothHrsandStamfail to degrade signaling receptors. However, mutant tissue surprisingly maintains normal apico-basal polarity and proliferation control and does not display ectopic Notch signaling activation, unlike cells that lack ESCRT-I, -II, -III activity. Overall, ourin vivodata indicate that the ESCRT-0 complex plays no crucial role in regulation of tumor suppression, and suggest re-evaluation of the relationship of signaling modulation in endosomes and tumorigenesis.
Migration and interaction in a contact zone: mtDNA variation among Bantu-speakers in southern Africa
Authors: Barbieri Chiara , Vicente Mário , Oliveira Sandra , Bostoen Koen , Rocha Jorge , Stoneking Mark , Pakendorf Brigitte 
Published: February 2014

ABSTRACTBantu speech communities expanded over large parts of sub-Saharan Africa within the last 4000-5000 years, reaching different parts of southern Africa 1200-2000 years ago. The Bantu languages subdivide in several major branches, with languages belonging to the Eastern and Western Bantu branches spreading over large parts of Central, Eastern, and Southern Africa. There is still debate whether this linguistic divide is correlated with a genetic distinction between Eastern and Western Bantu speakers. During their expansion, Bantu speakers would have come into contact with diverse local populations, such as the Khoisan hunter-gatherers and pastoralists of southern Africa, with whom they may have intermarried. In this study, we analyze complete mtDNA genome sequences from over 900 Bantu-speaking individuals from Angola, Zambia, Namibia, and Botswana to investigate the demographic processes at play during the last stages of the Bantu expansion. Our results show that most of these Bantu-speaking populations are genetically very homogenous, with no genetic division between speakers of Eastern and Western Bantu languages. Most of the mtDNA diversity in our dataset is due to different degrees of admixture with autochthonous populations. Only the pastoralist Himba and Herero stand out due to high frequencies of particular L3f and L3d lineages; the latter are also found in the neighboring Damara, who speak a Khoisan language and were foragers and small-stock herders. In contrast, the close cultural and linguistic relatives of the Herero and Himba, the Kuvale, are genetically similar to other Bantu-speakers. Nevertheless, as demonstrated by resampling tests, the genetic divergence of Herero, Himba, and Kuvale is compatible with a common shared ancestry with high levels of drift and differential female admixture with local pre-Bantu populations.
Interaction between theGROWTH-REGULATING FACTORandKNOTTED1-LIKE HOMEOBOXFamilies of Transcription Factors
Authors: Kuijt Suzanne J.H. , Greco Raffaella , Agalou Adamantia , Shao Jingxia , ‘t Hoen Corine C.J. , Övernäs Elin , Osnato Michela , Curiale Serena , Meynard Donaldo , van Gulik Robert , Maraschin Simone de Faria , Atallah Mirna , de Kam Rolf J. , Lamers Gerda E.M. , Guiderdoni Emmanuel , Rossini Laura , Meijer Annemarie H. , Ouwerkerk Pieter B.F. 
Published: February 2014

AbstractKNOTTED1-LIKE HOMEOBOX (KNOX) genes are important regulators of meristem function, and a complex network of transcription factors ensures tight control of their expression. Here, we show that members of the GROWTH-REGULATING FACTOR (GRF) family act as players in this network. A yeast (Saccharomyces cerevisiae) one-hybrid screen with the upstream sequence of the KNOX gene Oskn2 from rice (Oryza sativa) resulted in isolation of OsGRF3 and OsGRF10. Specific binding to a region in the untranslated leader sequence of Oskn2 was confirmed by yeast and in vitro binding assays. ProOskn2:β-glucuronidase reporter expression was down-regulated by OsGRF3 and OsGRF10 in vivo, suggesting that these proteins function as transcriptional repressors. Likewise, we found that the GRF protein BGRF1 from barley (Hordeum vulgare) could act as a repressor on an intron sequence in the KNOX gene Hooded/Barley Knotted3 (Bkn3) and that AtGRF4, AtGRF5, and AtGRF6 from Arabidopsis (Arabidopsis thaliana) could repress KNOTTED-LIKE FROM ARABIDOPSIS THALIANA2 (KNAT2) promoter activity. OsGRF overexpression phenotypes in rice were consistent with aberrant meristematic activity, showing reduced formation of tillers and internodes and extensive adventitious root/shoot formation on nodes. These effects were associated with down-regulation of endogenous Oskn2 expression by OsGRF3. Conversely, RNA interference silencing of OsGRF3, OsGRF4, and OsGRF5 resulted in dwarfism, delayed growth and inflorescence formation, and up-regulation of Oskn2. These data demonstrate conserved interactions between the GRF and KNOX families of transcription factors in both monocot and dicot plants.
Thinking about changing mobility practices: how a social practice approach can help
Authors: Nettleton Sarah , Green Judith 
Published: February 2014

AbstractPolicy efforts directed at encouraging physical activity have had minimal success to date. Drawing on Bourdieu's theory of practice, we suggest that a social practice framing might provide useful ways of thinking about why and how some practices do and could change. This article takes three case studies of transformations in mobility practices to explore conditions of possibility for change, using a secondary analysis of qualitative data from studies on cycling in London and fell running in the English Lake District. Three modes of transformation: unthinkable, thwarted and resisted, are rooted in differential interrelationships of field, habitus and doxa in these contrasting cases. We suggest that the notion of tacit, practical knowledge is more useful to understanding why change is thinkable or unthinkable than participants’ reasoned accounts of their practice; that where new social fields are available that are congruent with habitus, change is possible and that where field and habitus are tightly aligned, the conditions of possibility for change are reduced. Efforts directed at changing practice might usefully focus not on behaviour or environments but on identifying the social fields in which mobility practices are likely to be malleable. The sociology of public health needs to focus less on health behaviour and more on social practice.
Providers’ constructions of pregnant and early parenting women who use substances
Authors: Benoit Cecilia , Stengel Camille , Marcellus Lenora , Hallgrimsdottir Helga , Anderson John , MacKinnon Karen , Phillips Rachel , Zazueta Pilar , Charbonneau Sinead 
Published: February 2014

AbstractThe research literature indicates that problematic substance use as a form of health behaviour is poorly understood, being sometimes viewed as deviance, at other times as a disease, and most often as a combination of these states. The use of substances by women who are pregnant or new parents is often conceptualised within an individualised framework. Yet drinking alcohol and using other drugs during pregnancy and early parenthood cuts across social divisions and is shaped by socio‐structural contexts including health care. There is a growing body of literature that critically examines public health interventions that are aimed at implementing harm reduction and health promotion techniques in service delivery to help pregnant and early parenting women who are identified as problem substance users. We examine qualitative data from representatives of a recent harm reduction intervention, focusing, in particular, on providers’ individual conceptualisations of the problematic behaviour. Our results show that most study participants regard any substance use during pregnancy, birth and the postpartum period as fundamentally unacceptable. This framing of problematic substance use is accomplished via gendered responsibilisation of women as foetal incubators and primary caregivers of infants. We discuss our results in light of the current literature and suggest policy implications.
Why behavioural health promotion endures despite its failure to reduce health inequities
Authors: Baum Fran , Fisher Matthew 
Published: February 2014

AbstractIncreasing rates of chronic conditions have resulted in governments targeting health behaviour such as smoking, eating high‐fat diets, or physical inactivity known to increase risk for these conditions. In the process, many have become preoccupied with disease prevention policies focused excessively and narrowly on behavioural health‐promotion strategies. These aim to improve health status by persuading individuals to change their health behaviour. At the same time, health promotion policy often fails to incorporate an understanding of the social determinants of health, which recognises that health behaviour itself is greatly influenced by peoples’ environmental, socioeconomic and cultural settings, and that chronic diseases and health behaviour such as smoking are more prevalent among the socially or economically disadvantaged. We identify several reasons why behavioural forms of health promotion are inadequate for addressing social inequities in health and point to a dilemma that, despite these inadequacies and increasing evidence of the social determinants of health, behavioural approaches and policies have strong appeal to governments. In conclusion, the article promotes strategies addressing social determinants that are likely to reduce health inequities. The article also concludes that evidence alone will not result in health policies aimed at equity and that political values and will, and the pressure of civil society are also crucial.
Monetary Policy in a Very Open Economy: Some Major Analytical Issues
Authors: McCallum Bennett T. 
Published: February 2014

AbstractThis paper develops three considerations relevant to the possibility of modification of the Hong Kong currency board system for conducting monetary/exchange‐rate policy. The first concerns the system employed by Singapore, an economy similar in several ways to Hong Kong's, whereby the exchange rate is adjusted periodically in activist response to inflation and output developments. The second concerns a generalization, one that calls for adjustments of a weighted average of exchange rate and interest rate instruments, so designed to be effective whether the economy is, or is not, in a liquidity‐trap situation. Finally, the third topic concerns political‐economy aspects of policy, which tend to incline against the use of the activist systems.
An Optimal Currency Basket to Minimize Output and Inflation Volatility: Theory and an Application to Hong Kong
Authors: Ma Zihui , Cheng Leonard K. 
Published: February 2014

AbstractIn this paper we develop a theoretical model of an optimal currency basket for a small open economy. A currency basket for the home economy is defined as a chosen weighted average of a subset of foreign currencies, and an optimal currency basket is taken to be one that minimizes a given weighted average of the expected output volatility and expected inflation volatility. This theoretical model is then applied to Hong Kong, which has adopted a currency board system for close to 30 years. We estimate an optimal currency basket for Hong Kong and compare its performance with the existing currency board system as well as with currency baskets whose weights are given by export and import trade shares.
Currency Boards when Interest Rates are Zero
Authors: Cook David , Yetman James 
Published: February 2014

AbstractIn a fixed exchange rate system, any expectation that the peg may be abandoned will normally be reflected in an interest rate differential between instruments denominated in domestic and anchor currencies: the possibility of a revaluation will drive domestic interest rates below those in the anchor currency, for example. However, when interest rates are close to the zero lower bound, there is limited scope for exchange rate expectations to be reflected in interest rate differentials. Here we introduce a new mechanism, based on the central bank balance sheet, which works to bring about equilibrium in currency markets even when interest rates are zero. An expectation of exchange rate appreciation will cause foreign exchange reserves to swell, increasing the cost to policy‐makers of allowing an appreciation and, therefore, lowering the likelihood of the fixed exchange rate being abandoned. Under normal circumstances, this channel reinforces the equilibrating effect of interest rate differentials. When interest rates cannot adjust only this channel operates, implying that much larger changes in reserves are required to equilibrate currency markets. We develop a simple model to illustrate these arguments and find support for the predictions of the model using data for Hong Kong, the world's largest economy with a currency board.