bluuebunny/crossref_metadata_2025 huggingface dataset:
Methylobacterium pseudosasicola sp. nov. and Methylobacterium phyllostachyos sp. nov., isolated from bamboo leaf surfaces
Authors: Madhaiyan Munusamy , Poonguzhali Selvaraj
Published: April 2014

Two strains of Gram-negative, methylotrophic bacteria, isolated because of their abilities to promote plant growth, were subjected to a polyphasic taxonomic study. The isolates were strictly aerobic, motile, pink-pigmented, facultatively methylotrophic, non-spore-forming rods. The chemotaxonomic characteristics of the isolates included the presence of C18 : 1ω7c as the major cellular fatty acid. The DNA G+C contents of strains BL36T and BL47T were 69.4 and 69.8 mol%, respectively. 16S rRNA gene sequence analysis of strains BL36T and BL47T placed them under the genus

Methylobacterium,
with the pairwise sequence similarity between them and the type strains of closely related species ranging from 97.2 to 99.0 %. On the basis of their phenotypic and phylogenetic distinctiveness and the results of DNA–DNA hybridization analysis, the isolates represent two novel species within the genus

Methylobacterium

, for which the names Methylobacterium pseudosasicola sp. nov. (type strain BL36T = NBRC 105203T = ICMP 17621T) and Methylobacterium phyllostachyos sp. nov. (type strain BL47T = NBRC 105206T = ICMP 17619T) are proposed.
Morphological and proteomic analysis of early stage air–liquid interface biofilm formation in Mycobacterium smegmatis
Authors: Sochorová Zuzana , Petráčková Denisa , Sitařová Barbora , Buriánková Karolína , Bezoušková Silvia , Benada Oldřich , Kofroňová Olga , Janeček Jiří , Halada Petr , Weiser Jaroslav
Published: April 2014

We studied the early stages of pellicle formation by Mycobacterium smegmatis on the surface of a liquid medium [air–liquid interface (A–L)]. Using optical and scanning electron microscopy, we showed the formation of a compact biofilm pellicle from micro-colonies over a period of 8–30 h. The cells in the pellicle changed size and cell division pattern during this period. Based on our findings, we created a model of M. smegmatis A–L early pellicle formation showing the coordinate growth of cells in the micro-colonies and in the homogeneous film between them, where the accessibility to oxygen and nutrients is different. A proteomic approach utilizing high-resolution two-dimensional gel electrophoresis, in combination with mass spectrometry-based protein identification, was used to analyse the protein expression profiles of the different morphological stages of the pellicle. The proteins identified formed four expression groups; the most interesting of these groups contained the proteins with highest expression in the biofilm development phase, when the floating micro-colonies containing long and more robust cells associate into flocs and start to form a compact pellicle. The majority of these proteins, including GroEL1, are involved in cell wall synthesis or modification, mostly through the involvement of mycolic acid biosynthesis, and their expression maxima correlated with the changes in cell size and the rigidity of the bacterial cell wall observed by scanning electron microscopy.
Regulation of gene expression at low temperature: role of cold-inducible promoters
Authors: Singh Ashish Kumar , Sad Kirti , Singh Shailendra Kumar , Shivaji Sisinthy
Published: April 2014

Psychrophilic micro-organisms are the most dominant flora in cold habitats. Their unique ability to survive and multiply at low temperatures (<5 °C) is based on their ability to modulate the rigidity of the membrane, to transcribe, to translate and to catalyse biochemical reactions at low temperature. A number of genes are known to be upregulated during growth at low temperature and cold-inducible promoters are known to regulate the expression of genes at low temperature. In this review, we attempted to compile promoter sequences of genes that are cold-inducible so as to identify similarities and to compare the distinct features of each type of promoter when microbes are grown in the cold.
Excessive production and extreme editing of human metapneumovirus defective interfering RNA is associated with type I IFN induction
Authors: van den Hoogen Bernadette G. , van Boheemen Sander , de Rijck Jonneke , van Nieuwkoop Stefan , Smith Derek J. , Laksono Brigitta , Gultyaev Alexander , Osterhaus Albert D. M. E. , Fouchier Ron A. M.
Published: April 2014

Type I IFN production is one of the hallmarks of host innate immune responses upon virus infection. Whilst most respiratory viruses carry IFN antagonists, reports on human metapneumovirus (HMPV) have been conflicting. Using deep sequencing, we have demonstrated that HMPV particles accumulate excessive amounts of defective interfering RNA (DIs) rapidly upon in vitro passage, and that these are associated with IFN induction. Importantly, the DIs were edited extensively; up to 70 % of the original A and T residues had mutated to G or C, respectively. Such high editing rates of viral RNA have not, to our knowledge, been reported before. Bioinformatics and PCR assays indicated that adenosine deaminase acting on RNA (ADAR) was the most likely editing enzyme. HMPV thus has an unusually high propensity to generate DIs, which are edited at an unprecedented high frequency. The conflicting published data on HMPV IFN induction and antagonism are probably explained by DIs in virus stocks. The interaction of HMPV DIs with the RNA-editing machinery and IFN responses warrants further investigation.
Cell size regulation in bacteria
Authors: Amir Ariel
Published: April 2014

Various bacteria such as the canonical gram negative Escherichia coli or the well-studied gram positive Bacillus subtilis divide symmetrically after they approximately double their volume. Their size at division is not constant, but is typically distributed over a narrow range. Here, we propose an analytically tractable model for cell size control, and calculate the cell size and inter-division time distributions, and the correlations between these variables. We suggest ways of extracting the model parameters from experimental data, and show that existing data for E. coli supports partial size control, and a particular explanation: a cell attempts to add a constant volume from the time of initiation of DNA replication to the next initiation event. This hypothesis accounts for the experimentally observed correlations between mother and daughter cells as well as the exponential dependence of size on growth rate.
A novel Bayesian method for inferring and interpreting the dynamics of adaptive landscapes from phylogenetic comparative data
Authors: Uyeda Josef C , Harmon Luke J
Published: April 2014

Our understanding of macroevolutionary patterns of adaptive evolution has greatly increased with the advent of large-scale phylogenetic comparative methods. Widely used Ornstein-Uhlenbeck (OU) models can describe an adaptive process of divergence and selection. However, inference of the dynamics of adaptive landscapes from comparative data is complicated by interpretational difficulties, lack of identifiability among parameter values and the common requirement that adaptive hypotheses must be assigneda priori. Here we develop a reversible-jump Bayesian method of fitting multi-optima OU models to phylogenetic comparative data that estimates the placement and magnitude of adaptive shifts directly from the data. We show how biologically informed hypotheses can be tested against this inferred posterior of shift locations using Bayes Factors to establish whether oura priorimodels adequately describe the dynamics of adaptive peak shifts. Furthermore, we show how the inclusion of informative priors can be used to restrict models to biologically realistic parameter space and test particular biological interpretations of evolutionary models. We argue that Bayesian model-fitting of OU models to comparative data provides a framework for integrating of multiple sources of biological data--such as microevolutionary estimates of selection parameters and paleontological timeseries--allowing inference of adaptive landscape dynamics with explicit, process-based biological interpretations.
The invariance hypothesis implies domain-specific regions in visual cortex
Authors: Leibo Joel Z. , Liao Qianli , Anselmi Fabio , Poggio Tomaso
Published: April 2014

Is visual cortex made up of general-purpose information processing machinery, or does it consist of a collection of specialized modules? If prior knowledge, acquired from learning a set of objects is only transferable to new objects that share properties with the old, then the recognition system's optimal organization must be one containing specialized modules for different object classes. Our analysis starts from a premise we call the invariance hypothesis: that the computational goal of the ventral stream is to compute an invariant-to-transformations and discriminative signature for recognition. The key condition enabling approximate transfer of invariance without sacrificing discriminability turns out to be that the learned and novel objects transform similarly. This implies that the optimal recognition system must contain subsystems trained only with data from similarly-transforming objects and suggests a novel interpretation of domain-specific regions like the fusiform face area (FFA). Furthermore, we can define an index of transformation-compatibility, computable from videos, that can be combined with information about the statistics of natural vision to yield predictions for which object categories ought to have domain-specific regions in agreement with the available data. The result is a unifying account linking the large literature on view-based recognition with the wealth of experimental evidence concerning domain-specific regions.
Cytochrome P450 CYP81A12 and CYP81A21 Are Associated with Resistance to Two Acetolactate Synthase Inhibitors in Echinochloa phyllopogon
Authors: Iwakami Satoshi , Endo Masaki , Saika Hiroaki , Okuno Junichi , Nakamura Naoki , Yokoyama Masao , Watanabe Hiroaki , Toki Seiichi , Uchino Akira , Inamura Tatsuya
Published: April 2014

Previous studies have demonstrated multiple herbicide resistance in California populations of Echinochloa phyllopogon, a noxious weed in rice (Oryza sativa) fields. It was suggested that the resistance to two classes of acetolactate synthase-inhibiting herbicides, bensulfuron-methyl (BSM) and penoxsulam (PX), may be caused by enhanced activities of herbicide-metabolizing cytochrome P450. We investigated BSM metabolism in the resistant (R) and susceptible (S) lines of E. phyllopogon, which were originally collected from different areas in California. R plants metabolized BSM through O-demethylation more rapidly than S plants. Based on available information about BSM tolerance in rice, we isolated and analyzed P450 genes of the CYP81A subfamily in E. phyllopogon. Two genes, CYP81A12 and CYP81A21, were more actively transcribed in R plants compared with S plants. Transgenic Arabidopsis (Arabidopsis thaliana) expressing either of the two genes survived in media containing BSM or PX at levels at which the wild type stopped growing. Segregation of resistances in the F2 generation from crosses of R and S plants suggested that the resistance to BSM and PX were each under the control of a single regulatory element. In F6 recombinant inbred lines, BSM and PX resistances cosegregated with increased transcript levels of CYP81A12 and CYP81A21. Heterologously produced CYP81A12 and CYP81A21 proteins in yeast (Saccharomyces cerevisiae) metabolized BSM through O-demethylation. Our results suggest that overexpression of the two P450 genes confers resistance to two classes of acetolactate synthase inhibitors to E. phyllopogon. The overexpression of the two genes could be regulated simultaneously by a single trans-acting element in the R line of E. phyllopogon.
Phycobilisome-Deficient Strains of Synechocystis sp. PCC 6803 Have Reduced Size and Require Carbon-Limiting Conditions to Exhibit Enhanced Productivity
Authors: Lea-Smith David J. , Bombelli Paolo , Dennis John S. , Scott Stuart A. , Smith Alison G. , Howe Christopher J.
Published: April 2014

Reducing excessive light harvesting in photosynthetic organisms may increase biomass yields by limiting photoinhibition and increasing light penetration in dense cultures. The cyanobacterium Synechocystis sp. PCC 6803 harvests light via the phycobilisome, which consists of an allophycocyanin core and six radiating rods, each with three phycocyanin (PC) discs. Via targeted gene disruption and alterations to the promoter region, three mutants with two (pcpcT→C) and one (ƊCpcC1C2:pcpcT→C) PC discs per rod or lacking PC (olive) were generated. Photoinhibition and chlorophyll levels decreased upon phycobilisome reduction, although greater penetration of white light was observed only in the PC-deficient mutant. In all strains cultured at high cell densities, most light was absorbed by the first 2 cm of the culture. Photosynthesis and respiration rates were also reduced in the ƊCpcC1C2:pcpcT→C and olive mutants. Cell size was smaller in the pcpcT→C and olive strains. Growth and biomass accumulation were similar between the wild-type and pcpcT→C under a variety of conditions. Growth and biomass accumulation of the olive mutant were poorer in carbon-saturated cultures but improved in carbon-limited cultures at higher light intensities, as they did in the ƊCpcC1C2:pcpcT→C mutant. This study shows that one PC disc per rod is sufficient for maximal light harvesting and biomass accumulation, except under conditions of high light and carbon limitation, and two or more are sufficient for maximal oxygen evolution. To our knowledge, this study is the first to measure light penetration in bulk cultures of cyanobacteria and offers important insights into photobioreactor design.
Structure of tyrosine aminotransferase fromLeishmania infantum
Authors: Moreno M. A. , Abramov A. , Abendroth J. , Alonso A. , Zhang S. , Alcolea P. J. , Edwards T. , Lorimer D. , Myler P. J. , Larraga V.
Published: April 2014

The trypanosomatid parasiteLeishmania infantumis the causative agent of visceral leishmaniasis (VL), which is usually fatal unless treated. VL has an incidence of 0.5 million cases every year and is an important opportunistic co-infection in HIV/AIDS. Tyrosine aminotransferase (TAT) has an important role in the metabolism of trypanosomatids, catalyzing the first step in the degradation pathway of aromatic amino acids, which are ultimately converted into their corresponding L-2-oxoacids. Unlike the enzyme inTrypanosoma cruziand mammals,L. infantumTAT (LiTAT) is not able to transaminate ketoglutarate. Here, the structure of LiTAT at 2.35 Å resolution is reported, and it is confirmed that the presence of twoLeishmania-specific residues (Gln55 and Asn58) explains, at least in part, this specific reactivity. The difference in substrate specificity between leishmanial and mammalian TAT and the importance of this enzyme in parasite metabolism suggest that it may be a useful target in the development of new drugs against leishmaniasis.
Crystallization and preliminary crystallographic analysis of human muscle phosphofructokinase, the main regulator of glycolysis
Authors: Kloos Marco , Brüser Antje , Kirchberger Jürgen , Schöneberg Torsten , Sträter Norbert
Published: April 2014

Whereas the three-dimensional structure and the structural basis of the allosteric regulation of prokaryotic 6-phosphofructokinases (Pfks) have been studied in great detail, knowledge of the molecular basis of the allosteric behaviour of the far more complex mammalian Pfks is still very limited. The human muscle isozyme was expressed heterologously in yeast cells and purified using a five-step purification protocol. Protein crystals suitable for diffraction experiments were obtained by the vapour-diffusion method. The crystals belonged to space groupP6222 and diffracted to 6.0 Å resolution. The 3.2 Å resolution structure of rabbit muscle Pfk (rmPfk) was placed into the asymmetric unit and optimized by rigid-body and groupB-factor refinement. Interestingly, the tetrameric enzyme dissociated into a dimer, similar to the situation observed in the structure of rmPfk.
Urban cultivation in allotments maintains soil qualities adversely affected by conventional agriculture
Authors: Edmondson Jill L. , Davies Zoe G. , Gaston Kevin J. , Leake Jonathan R.
Published: April 2014

Modern agriculture, in seeking to maximize yields to meet growing global food demand, has caused loss of soil organic carbon (SOC) and compaction, impairing critical regulating and supporting ecosystem services upon which humans also depend. Own‐growing makes an important contribution to food security in urban areas globally, but its effects on soil qualities that underpin ecosystem service provision are currently unknown.

We compared the main indicators of soil quality; SOC storage, total nitrogen (TN), C : N ratio and bulk density (BD) in urban allotments to soils from the surrounding agricultural region, and between the allotments and other urban greenspaces in a typical UK city. A questionnaire was used to investigate allotment management practices that influence soil properties.

Allotment soils had 32% higher SOC concentrations and 36% higher C : N ratios than pastures and arable fields and 25% higher TN and 10% lower BD than arable soils.

There was no significant difference between SOC concentration in allotments and urban non‐domestic greenspaces, but it was higher in domestic gardens beneath woody vegetation. Allotment soil C : N ratio exceeded that in non‐domestic greenspaces, but was lower than that in garden soil.

Three‐quarters of surveyed allotment plot holders added manure, 95% composted biomass on‐site, and many added organic‐based fertilizers and commercial composts. This may explain the maintenance of SOC, C : N ratios, TN and low BD, which are positively associated with soil functioning.

Synthesis and applications. Maintenance and protection of the quality of our soil resource is essential for sustainable food production and for regulating and supporting ecosystem services upon which we depend. Our study establishes, for the first time, that small‐scale urban food production can occur without the penalty of soil degradation seen in conventional agriculture, and maintains the high soil quality seen in urban greenspaces. Given the involvement of over 800 million people in urban agriculture globally, and its important contribution to food security, our findings suggest that to better protect soil functions, local, national and international urban planning and policy making should promote more urban own‐growing in preference to further intensification of conventional agriculture to meet increasing food demand.
Does It Pay to Be Moral? How Indicators of Morality and Competence Enhance Organizational and Work Team Attractiveness
Authors: van Prooijen Anne‐Marie , Ellemers Naomi
Published: April 2014

Based on a social identity analysis, the authors argue that people are attracted to teams and organizations with positive features. Such features can refer to thecompetenceand achievements of the organization, or to itsmoralvalues and ethical conduct. However, in work contexts, ethics and achievements do not necessarily go together. The paper reports three studies that examine the relative and combined impact of perceived competence vs morality of a team or organization on its attractiveness to individuals. Study 1 (n = 44) reveals that students prefer to seek employment in a moral rather than a competent organization, when forced to choose between these organizational features on a bipolar scale. Study 2 (n = 100) replicates these findings in a design where the competence and morality of a fictitious organization were manipulated orthogonally. Study 3 (n = 89) examines responses to experimental task teams that systematically differed from each other in their competence and morality. Results of all three studies converge to demonstrate that the perceived morality of the team or organization has a greater impact on its attractiveness to individuals than its perceived competence. The authors discuss the theoretical and practical implications of these findings.
Lessons from The Wire: Epistemological Reflections on the Practice of Sociological Research
Authors: Wood Matthew
Published: April 2014

Recent debates and controversies have highlighted several issues surrounding sociological research, which relate to the general conditions under which it is undertaken and how this is changing. There is a pressing need to respond to these issues as a whole, in particular by examining what they tell us about research practices. This article argues that a consideration of themes raised by the American television drama The Wire is useful for facilitating such a response, since it may be read as a discussion of working conditions within neoliberal societies. The following themes are pertinent here: the need to reflect upon the terms by which research is framed by funders, to take adequate time to conduct and complete research, and to encourage critical debate within research. Whilst these relate to influential epistemological discussions by Pierre Bourdieu and Michael Burawoy, this reading of The Wire is particularly helpful for highlighting the practical and inter-relational situations in which sociological research is carried out but which tend not to receive the systematic attention they deserve.
TheHR–performance link using two differently measuredHRpractices
Authors: Choi Jang‐Ho
Published: April 2014

Previous studies have supported the association between high‐performance work systems and firm performance; however,HRpractices were measured in various ways. This study demonstrates the relationships between three aspects of high‐performance work systems (ability‐enhancing, motivation‐enhancing, and opportunity‐enhancingHRpractices) and performance of a firm (financial performance and job satisfaction of employees) amongSouthKorean firms. In addition, this study compares the relative predictive power of two measures ofHRpractices (the perceived presence and the perceived effectiveness). The findings reveal that the effectiveness measure accounts for more of the variance in financial performance and employee job satisfaction than the presence measure.
Determination of Lutein from Green Tea and Green Tea By‐Products Using Accelerated Solvent Extraction and UPLC
Authors: Heo Ji‐Young , Kim Suna , Kang Jae‐Hyun , Moon BoKyung
Published: April 2014

We aimed to identify the optimum conditions for the extraction of lutein from green tea using accelerated solvent extraction, and achieve improved analytical resolution and sensitivity between lutein and zeaxanthin using an ultra performance liquid chromatography (UPLC) system. The optimized method employed 80% ethanol as the extraction solvent, 160 °C as the temperature, 2 static cycles, and 5 min of static time. In the validation of the UPLC method, recovery was found to be in the range approximately 93.73 to 108.79%, with a correlation coefficient of 0.9974 and a relative standard deviation of <9.29% in inter‐ and intraday precision analyses. Finally, the lutein contents of green tea and green tea by‐products were measured as 32.67 ± 0.70 and 18.18 ± 0.68 mg/100g dw, respectively. Furthermore, we verified that green tea by‐products, which are discarded after producing green tea beverages, might be used as a great resource for massive lutein production.

Practical Application

We have demonstrated that the common problem of inadequate resolution between lutein and zeaxanthin during carotenoid analyses can be overcome by optimizing the combined techniques of accelerated solvent extraction and ultra performance liquid chromatography (UPLC). UPLC was highly effective for saving time, solvent, and labor, as well as providing better resolution. The results in this study demonstrated that green tea by‐products could be used as new sources for industrial lutein production owing to their massive production during the extraction of green tea beverages.
Degradation of Endogenous and Exogenous Genes of Genetically Modified Rice with Cry1Ab during Food Processing
Authors: Zhang Wei , Xing Fuguo , Selvaraj Jonathan Nimal , Liu Yang
Published: April 2014

In order to assess the degradation of endogenous and exogenous genes during food processing, genetically modified rice with Cry1Ab was used as raw material to produce 4 processed foods: steamed rice, rice noodles, rice crackers, and sweet rice wine. The results showed various processing procedures caused different degrees of degradation of both endogenous and exogenous genes. During the processing of steamed rice and rice noodles, the procedures were so mild that only genes larger than 1500 bp were degraded, and no degradation of NOS terminator and Hpt gene was detected. For rice crackers, frying was the most severe procedure, followed by microwaving, baking, boiling, 1st drying, and 2nd drying. For sweet rice wine, fermentation had more impact on degradation of genes than the other processing procedures. All procedures in this study did not lead to degradation of genes to below 200 bp, except for NOS terminator. In the case of stability of the genes studied during processing of rice crackers and sweet rice wine, SPS gene was the most, followed by the Cry1Ab gene, Hpt gene, Pubi promoter, and NOS terminator.

Practical Application

In our study, we gained some information about the degradation of endogenous and exogenous genes during 4 foods processing, compared the different stabilities between endogenous and exogenous genes, and analyzed different effects of procedure on degradation of genes. In addition, the fragments of endogenous and exogenous genes about 200 bp could be detected in final products, except NOS terminator. As a result, we provided some base information about risk assessment of genetically modified (GM) food and appropriate length of fragment to detect GM component in processed foods.
Electron transport and protein secretion pathways involved in Mn(III) reduction by Shewanella oneidensis
Authors: Szeinbaum Nadia , Burns Justin L. , DiChristina Thomas J.
Published: April 2014

Soluble Mn(III) represents an important yet overlooked oxidant in marine and freshwater systems. The molecular mechanism of microbial Mn(III) reduction, however, has yet to be elucidated. Extracellular reduction of insoluble Mn(IV) and Fe(III) oxides by the metal‐reducing γ‐proteobacterium Shewanella oneidensis involves inner (CymA) and outer (OmcA) membrane‐associated c‐type cytochromes, the extracellular electron conduit MtrCAB, and GspD, the secretin of type II protein secretion. CymA, MtrCAB and GspD mutants were unable to reduce Mn(III) and Mn(IV) with lactate, H2, or formate as electron donor. The OmcA mutant reduced Mn(III) and Mn(IV) at near wild‐type rates with lactate and formate as electron donor. With H2 as electron donor, however, the OmcA mutant was unable to reduce Mn(III) but reduced Mn(IV) at wild‐type rates. Analogous Fe(III) reduction rate analyses indicated that other electron carriers compensated for the absence of OmcA, CymA, MtrCAB and GspD during Fe(III) reduction in an electron donor‐dependent fashion. Results of the present study demonstrate that the S. oneidensis electron transport and protein secretion components involved in extracellular electron transfer to external Mn(IV) and Fe(III) oxides are also required for electron transfer to Mn(III) and that OmcA may function as a dedicated component of an H2 oxidation‐linked Mn(III) reduction system.
Variation of prey responses to cues from a mesopredator and an apex predator
Authors: Cremona Teigan , Crowther Mathew S. , Webb Jonathan K.
Published: April 2014

Detection and avoidance of predator cues can be costly, so it is important for prey to balance the benefits of gaining food against the costs of avoiding predators. Balancing these factors becomes more complicated when prey are threatened by more than one type of predator. Hence, the ability to recognize species‐specific predator odours and prioritize behaviours according to the level of risk is essential for survival. We investigated how rock rats, Zyzomys spp. modify their foraging behaviour and giving‐up density (GUD) in the presence of an apex predator, the dingo Canis dingo, a mesopredator, the northern quoll Dasyurus hallucatus, a herbivore, the rock wallaby Petrogale brachyotis as a pungency control and water as a procedural control. Both dingoes and quolls consume rock rats, but because quolls can enter small crevices inhabited by rock rats, they pose a greater threat to rock rats than dingoes. Rock rats demonstrated a stronger avoidance to quoll odour than dingo odour, and no avoidance of the pungency control (rock wallaby) and the procedural control (water). GUD values declined significantly over the duration of the study, but did not differ between odour treatments. Our results support the hypothesis that prey vary behaviour according to perceived predator threat, and show stronger responses to potentially more dangerous predators.
QT Interval Prolongation in End‐Stage Liver Disease Cannot Be Explained by Nonhepatic Factors
Authors: Patel Divyang , Singh Prabhpreet , Katz William , Hughes Christopher , Chopra Kapil , Němec Jan
Published: April 2014

Introduction

QT interval prolongation in patients with end‐stage liver disease (ESLD) is common. However, electrolyte abnormalities, renal insufficiency, treatment with QT‐prolonging drugs, and other factors known to prolong QT interval independently of liver disease occur frequently in ESLD. Moreover, elevated heart rate may be present in ESLD and result in spurious QTc prolongation if the Bazett formula is used for rate correction. It thus remains unclear whether QT prolongation in ESLD is directly caused by liver failure, or indirectly by these confounding factors.

Methods

Medical records of all patients (n = 437) who received orthotopic liver transplantation (OLTx) at our institution between 2008 and 2011 were reviewed. Data from 51 patients with available pre‐OLTx dobutamine stress echo (DSE), post‐OLTx ECG and without nonhepatic factors affecting QT interval duration were analyzed. For each patient, QT versus RR regression line was calculated from ECG tracings obtained during DSE. The QT interval on post‐OLTx ECG was compared with the pre‐OLTx QT predicted by the regression line for the same RR interval.

Results

QT interval shortened significantly post‐OLTx (from 394 ± 47 to 364 ± 45 ms at RR interval 750 ± 144 ms; P < 0.002) when compared using the regression method. Corrected QT intervals calculated by Bazett and Fridericia formulas also shortened. Patients with prolonged QT pre‐OLTx had significantly higher INR and lower serum albumin.

Conclusion

ESLD impairs ventricular repolarization even in the absence of other known factors affecting repolarization. QT prolongation in ESLD is associated with impaired synthetic liver function.
Bone morphogenetic proteins and their antagonists: current and emerging clinical uses
Authors: Ali Imran H A , Brazil Derek P
Published: April 2014

Bone morphogenetic proteins (BMPs) are members of the TGFβ superfamily of secreted cysteine knot proteins that includes TGFβ1, nodal, activins and inhibins. BMPs were first discovered by Urist in the 1960s when he showed that implantation of demineralized bone into intramuscular tissue of rabbits induced bone and cartilage formation. Since this seminal discovery, BMPs have also been shown to play key roles in several other biological processes, including limb, kidney, skin, hair and neuronal development, as well as maintaining vascular homeostasis. The multifunctional effects of BMPs make them attractive targets for the treatment of several pathologies, including bone disorders, kidney and lung fibrosis, and cancer. This review will summarize current knowledge on the BMP signalling pathway and critically evaluate the potential of recombinant BMPs as pharmacological agents for the treatment of bone repair and tissue fibrosis in patients.
Retracted: Rutin protects against cognitive deficits and brain damage in rats with chronic cerebral hypoperfusion
Authors: Qu Jie , Zhou Qiong , Du Ying , Zhang Wei , Bai Miao , Zhang Zhuo , Xi Ye , Li Zhuyi , Miao Jianting
Published: April 2014

Background and Purpose

Chronic cerebral hypoperfusion is a critical causative factor for the development of cognitive decline and dementia in the elderly, which involves many pathophysiological processes. Consequently, inhibition of several pathophysiological pathways is an attractive therapeutic strategy for this disorder. Rutin, a biologically active flavonoid, protects the brain against several insults through its antioxidant and anti‐inflammatory properties, but its effect on cognitive deficits and brain damage caused by chronic cerebral hypoperfusion remains unknown. Here, we investigated the neuroprotective effect of rutin on cognitive impairments and the potential mechanisms underlying its action in rats with chronic cerebral hypoperfusion.

Experimental Approach

We used Sprague‐Dawley rats with permanent bilateral common carotid artery occlusion (BCCAO), a well‐established model of chronic cerebral hypoperfusion. After rutin treatment for 12 weeks, the neuroprotective effect of rutin in rats was evaluated by behavioural tests, biochemical and histopathological analyses.

Key Results

BCCAO rats showed marked cognitive deficits, which were improved by rutin treatment. Moreover, BCCAO rats exhibited central cholinergic dysfunction, oxidative damage, inflammatory responses and neuronal damage in the cerebral cortex and hippocampus, compared with sham‐operated rats. All these effects were significantly alleviated by treatment with rutin.

Conclusion and Implications

Our results provide new insights into the pharmacological actions of rutin and suggest that rutin has multi‐targeted therapeutical potential on cognitive deficits associated with conditions with chronic cerebral hypoperfusion such as vascular dementia and Alzheimer's disease.
Hypoxia augments the calcium‐activated chloride current carried by anoctamin‐1 in cardiac vascular endothelial cells of neonatal mice
Authors: Wu Ming‐Ming , Lou Jie , Song Bin‐Lin , Gong Yuan‐Feng , Li Yan‐Chao , Yu Chang‐Jiang , Wang Qiu‐Shi , Ma Tian‐Xing , Ma Ke , Hartzell H Criss , Duan Dayue Darrel , Zhao Dan , Zhang Zhi‐Ren
Published: April 2014

Background and Purpose

The molecular identity of calcium‐activated chloride channels (CaCCs) in vascular endothelial cells remains unknown. This study sought to identify whether anoctamin‐1 (Ano1, also known as TMEM16A) functions as a CaCC and whether hypoxia alters the biophysical properties of Ano1 in mouse cardiac vascular endothelial cells (CVECs).

Experimental Approach

Western blot, quantitative real‐time PCR, confocal imaging analysis and patch‐clamp analysis combined with pharmacological approaches were used to determine whether Ano1 was expressed and functioned as CaCC in CVECs.

Key Results

Ano1 was expressed in CVECs. The biophysical properties of the current generated in the CVECs, including the Ca2+ and voltage dependence, outward rectification, anion selectivity and the pharmacological profile, are similar to those described for CaCCs. The density of ICl(Ca) detected in CVECs was significantly inhibited by T16Ainh‐A01, an Ano1 inhibitor, and a pore‐targeting, specific anti‐Ano1 antibody, and was markedly decreased in Ano1 gene knockdown CVECs. The density of ICl(Ca) was significantly potentiated in CVECs exposed to hypoxia, and this hypoxia‐induced increase in the density of ICl(Ca) was inhibited by T16Ainh‐A01 or anti‐Ano1 antibody. Hypoxia also increased the current density of ICl(Ca) in Ano1 gene knockdown CVECs.

Conclusions and Implications

Ano1 formed CaCC in CVECs of neonatal mice. Hypoxia enhances Ano1‐mediated ICl(Ca) density via increasing its expression, altering the ratio of its splicing variants, sensitivity to membrane voltage and to Ca2+. Ano1 may play a role in the pathophysiological processes during ischaemia in heart, and therefore, Ano1 might be a potential therapeutic target to prevent ischaemic damage.
Practical Science Communication Strategies for Graduate Students
Authors: KUEHNE LAUREN M. , TWARDOCHLEB LAURA A. , FRITSCHIE KEITH J. , MIMS MERYL C. , LAWRENCE DAVID J. , GIBSON POLLY P. , STEWART‐KOSTER BEN , OLDEN JULIAN D.
Published: April 2014

Development of skills in science communication is a well‐acknowledged gap in graduate training, but the constraints that accompany research (limited time, resources, and knowledge of opportunities) make it challenging to acquire these proficiencies. Furthermore, advisors and institutions may find it difficult to support graduate students adequately in these efforts. The result is fewer career and societal benefits because students have not learned to communicate research effectively beyond their scientific peers. To help overcome these hurdles, we developed a practical approach to incorporating broad science communication into any graduate‐school time line. The approach consists of a portfolio approach that organizes outreach activities along a time line of planned graduate studies. To help design the portfolio, we mapped available science communication tools according to 5 core skills essential to most scientific careers: writing, public speaking, leadership, project management, and teaching. This helps graduate students consider the diversity of communication tools based on their desired skills, time constraints, barriers to entry, target audiences, and personal and societal communication goals. By designing a portfolio with an advisor's input, guidance, and approval, graduate students can gauge how much outreach is appropriate given their other commitments to teaching, research, and classes. The student benefits from the advisors’ experience and mentorship, promotes the group's research, and establishes a track record of engagement. When graduate student participation in science communication is discussed, it is often recommended that institutions offer or require more training in communication, project management, and leadership. We suggest that graduate students can also adopt a do‐it‐yourself approach that includes determining students’ own outreach objectives and time constraints and communicating these with their advisor. By doing so we hope students will help create a new culture of science communication in graduate student education.

Estrategias Prácticas para la Comunicación Científica para Estudiantes de Posgrado
“They Will Take the Country from Us”:LaborZionism, the Origins and Legacy of the “Other” inIsraeli Mass Media, and Hegemonic Narratives
Authors: Frantzman Seth J.
Published: April 2014

After 1948,Israel's governing elites embarked on a rigorous program of state building and settling hundreds of thousands ofJewish immigrants. In the process, the elites, primarily from the leadingMapai party, developed a process of otheringJewish immigrants fromArab countries,Arab citizens, andOrthodoxJews. They were physically segregated in their own schools and communities, and the elite culture described them as a threat against theEuropean culture ofJewish immigrants from centralEurope. The process targetedMizrahiJews before moving on to deplore the “demographic threat” ofOrthodoxJews and resulted in the current normative hegemonic discourse inIsrael that paints numerous groups as threatening the state. This article proposes a four‐part model for understanding “the other” inIsrael: contemporary denial and nostalgia for a homogenous past, the view ofZionism as a civilizing mission, the application of separation of ethnic groups in planning, and demographic fear of the other. Altogether, they paint a picture of anIsrael that has not come to grips with its past, and therefore continues the process of “othering” in its contemporary ethnocratic framework. Combining the analysis of geographic separation, and planning and media, it presents an innovative understanding of Israeli society.
Sidelining the Hardliners: A 2+1 Solution forIsrael‐Palestine
Authors: Ferrero Christopher J.
Published: April 2014

This article presents a modified two‐state solution to theIsraeli‐Palestinian conflict. A “2 + 1 solution” would see the establishment of aState ofPalestine in theWestBank whose constitution proscribes the participation in government of any party whose platform calls for the elimination ofIsrael;Gaza would accede upon the reform or demise ofHamas. Achieving a state in theWestBank should be the proximate, urgent goal of thePalestinian people. Ideologically motivatedIsraeli settlement of theWestBank continues apace and threatens the viability of a two‐state solution. Meanwhile, religiously motivated policies of colonization hide behind a security narrative conflatingHamas withFatah and suggesting that thePalestinians pose an existential threat. The 2 + 1 solution, by excludingHamas from aState ofPalestine, directly addressesIsrael's legitimate security concerns and thus carries the potential to lay bare the extent to which ideology informsIsraeli policy. The approach also gives moderatePalestinians the opportunity to define the civic values and attributes ofPalestinian national identity in a way that supports a lasting two‐state peace.
Merger andAcquisition Activity as Driver of Spatial Clustering: The Spatial Evolution of theDutch Banking Industry, 1850–1993
Authors: Boschma Ron , Hartog Matté
Published: April 2014

This article investigates the extent to which merger and acquisition (M&A) activity contributed to the spatial clustering of theDutch banking industry inAmsterdam. This analysis is based on a unique database of all banks in theNetherlands that existed in the period 1850–1993. We found that spatial clustering of theDutch banking industry was not driven by the fact that banks performed better in theAmsterdam region: being located inAmsterdam decreased rather than increased the survival chances of banks. However, banks inAmsterdam were disproportionally active in acquiring other banks outsideAmsterdam. Experience inM&As accumulated mainly in the Amsterdam region, which in turn had a positive impact on the survival chances of banks located there. Our findings suggest thatM&Aactivity was a driving force behind the spatial clustering of theDutch banking industry between 1850 and 1993.
Teacher Educators: hidden professionals?
Authors: Livingston Kay
Published: April 2014

The pace of change in today's society means that there is an ongoing need for teachers to learn, have new knowledge and use new pedagogical approaches to meet the needs of their pupils. For many teachers, this requires redefining their identity as teachers and what ‘teaching’ means in 21st century learning environments. These changes also require teachers to be supported in learning to ‘teach’ in different ways that are relevant to their own individual needs and to the contexts in which they work throughout their career. In this article, it is argued that a more integrated and collaborative approach to teacher education is needed with better understanding of those who take up the roles of teacher educator across a teacher's career. With a particular emphasis on ‘teacher educators’ working in school to support teachers' career‐long professional learning it is argued that currently many do not recognise themselves as teacher educators nor are they recognised by those they work with as teacher educators. Drawing on an empirical study carried out with mentors in schools in Scotland, it is suggested that these teacher educators may be ‘unrecognised’ and remain ‘hidden professionals’ because of the identities they construct for themselves, the values and priorities that they or others attach to their roles or because of the institutional structures and cultures in which they work. It is concluded that it will be difficult to recognise and value these ‘hidden teacher educators’ and the distinctive contribution they can make to teachers' career‐long professional learning without further clarification by them and others of the roles and responsibilities they hold.
Evaluation of a rapid von Willebrand Factor Activity Latex Immuno Assay for monitoring of patients with von Willebrand disease (VWD) receiving DDAVP® or VWF replacement therapy
Authors: Vinayagam S. , Simons L. R. , Chowdary P. , Thurlow P. , Brooks S. V. , Riddell A. F.
Published: April 2014

Haemostatic management of surgery in patients with von Willebrand disease (VWD) includes DDAVP® or von Willebrand factor (VWF)‐containing concentrates. Although the recommendations are for monitoring by VWF activity assays, it is quite common for clinicians to use factor VIII due usually to longer turnaround times required for VWF ristocetin cofactor assay (VWF:RCo) measurements. The aim of this study was to evaluate use of the rapid HaemosIL™ VWF activity (VWF:Act) latex immuno assay (LIA) on an automated coagulometer (ACL TOP™ 700; Instrumentation Laboratory, Bedford, MA, USA) compared to platelet‐based VWF:RCo assays in this setting. One hundred and sixty‐seven plasma samples from 42 patients [Type 1 (n = 22), Type 2A (n = 2), Type 2B (n = 3), Type 2M (n = 10), Type 3 (n = 3)] and acquired von Willebrand syndrome (n = 2) with VWD treated with DDAVP® or VWF‐containing concentrates were included in the study. Method comparison and method bias were evaluated by Bland–Altman analysis (BA) and Passing and Bablok regression modelling respectively. BA of baseline samples (n = 39) showed a mean difference of −3.0 (±1.96 SD −25.2 to +19.4). Post (treatment) samples (n = 120) were separated into two groups. Group 1 contained samples with VWF:RCo levels 10 to ≤175 IU dL−1 (n = 97) and group 2, samples with VWF:RCo levels >175 IU dL−1 (n = 23). BA of group 1 postsamples showed a mean difference of +3.4 (±1.96 SD −44.6 to +51.5), and the BA of Group 2 samples was −23.9 (±1.96 SD −136.1 to +88.3). In conclusion, use of HaemosIL VWF:Act LIA test on an automated coagulometer is a reproducible and rapid assay that can be used as an alternative test for monitoring VWF replacement therapy, facilitating dose adjustments on a real‐time basis.
High Exposure, Spontaneous Clearance, and Low Incidence of Active Helicobacter pylori Infection: The Sorbo San Basile Study
Authors: Luzza Francesco , Suraci Evelina , Larussa Tiziana , Leone Isabella , Imeneo Maria
Published: April 2014

Background

A decreased incidence of Helicobacter pylori infection has been prospected to occur nowadays.

Aim

To evaluate the exposure to H. pylori, prevalence and incidence of active infection, and related risk factors in the general population.

Methods

In a small town of Southern Italy (932 inhabitants), 595 (3–97 years) and 157 (12–82 years) subjects among those with no evidence of active H. pylori infection participated at baseline and 10 years later, respectively. A questionnaire was administered. Active H. pylori infection was assessed by 13C‐urea breath test (UBT). Serum VacA and CagA antibodies were determined.

Results

Of 518 subjects who were evaluated by both UBT and serology, 310 (59.8%) were UBT positive, 479 (92.4%) VacA positive, and 369 (71.2%) CagA positive. Subjects UBT negative and serology positive were 169 (32%), ranging 1 (14.2%) to 29 (82.8%) from last to first decades of life. Age, female gender, and people per room were independent risk factors for subjects UBT positive compared to those UBT negative and serology positive. Ten years later, subjects who became UBT positive were four of 157 (0.25% per year) while those who became seropositive for VacA and/or CagA were 17 of 26 (6.5% per year).

Conclusions

H. pylori infection is highly dynamic with wide range of spontaneous clearance. It is easily cleared in the first decades of life, more recent years, less crowded homes, and males. It disappears and recurs more often than it was previously thought, implying that the current decline in its prevalence is due to real clearance instead of a fall in infection rate.