bluuebunny/crossref_metadata_2025 huggingface dataset:
Spontaneous cleavage of proteins at serine and threonine is facilitated by zinc
Authors: Lyons Brian , Kwan Ann H. , Truscott Roger J.W.
Published: January 2016

Old proteins are widely distributed in the body. Over time, they deteriorate and many spontaneous reactions, for example isomerisation of Asp and Asn, can be replicated by incubation of peptides under physiological conditions. One of the signatures of long‐lived proteins that has proven to be difficult to replicate in vitro is cleavage on the N‐terminal side of Ser residues, and this is important since cleavage at Ser, and also Thr, has been observed in a number of human proteins. In this study, the autolysis of Ser‐ and Thr‐containing peptides was investigated with particular reference to discovering factors that promote cleavage adjacent to Ser/Thr at neutral pH. It was found that zinc catalyses cleavage of the peptide bond on the N‐terminal side of Ser residues and further that this process is markedly accelerated if a His residue is adjacent to the Ser. NMR analysis indicated that the imidazole group co‐ordinates zinc and that once zinc is co‐ordinated, it can polarize the carbonyl group of the peptide bond in a manner analogous to that observed in the active site of the metalloexopeptidase, carboxypeptidase A. The hydroxyl side chain of Ser/Thr is then able to cleave the adjacent peptide bond. These observations enable an understanding of the origin of common truncations observed in long‐lived proteins, for example truncation on the N‐terminal side of Ser 8 in Abeta, Ser 19 in alpha B crystallin and Ser 66 in alpha A crystallin. The presence of zinc may therefore significantly affect the long‐term stability of cellular proteins.
Characterization of age‐associated exhausted CD8+ T cells defined by increased expression of Tim‐3 and PD‐1
Authors: Lee Kyoo‐A , Shin Kwang‐Soo , Kim Ga‐Young , Song You Chan , Bae Eun‐Ah , Kim Il‐Kyu , Koh Choong‐Hyun , Kang Chang‐Yuil
Published: January 2016

Aging is accompanied by altered T‐cell responses that result in susceptibility to various diseases. Previous findings on the increased expression of inhibitory receptors, such as programmed cell death protein 1 (PD‐1), in the T cells of aged mice emphasize the importance of investigations into the relationship between T‐cell exhaustion and aging‐associated immune dysfunction. In this study, we demonstrate that T‐cell immunoglobulin mucin domain‐3 (Tim‐3), another exhaustion marker, is up‐regulated on aged T cells, especially CD8+ T cells. Tim‐3‐expressing cells also produced PD‐1, but Tim‐3+PD‐1+ CD8+ T cells had a distinct phenotype that included the expression of CD44 and CD62L, from Tim‐3−PD‐1+ cells. Tim‐3+PD‐1+ CD8+ T cells showed more evident properties associated with exhaustion than Tim‐3−PD‐1+ CD8+ T cells: an exhaustion‐related marker expression profile, proliferative defects following homeostatic or TCR stimulation, and altered production of cytokines. Interestingly, these cells produced a high level of IL‐10 and induced normal CD8+ T cells to produce IL‐10, which might contribute to immune dysregulation in aged mice. The generation of Tim‐3‐expressing CD8+ T cells in aged mice seems to be mediated by encounters with antigens but not by specific infection, based on their high expression of CD49d and their unbiased TCR Vβ usage. In conclusion, we found that a CD8+ T‐cell population with age‐associated exhaustion was distinguishable by its expression of Tim‐3. These results provide clues for understanding the alterations that occur in T‐cell populations with age and for improving dysfunctions related to the aging of the immune system.
Defects in MAP1S‐mediated autophagy cause reduction in mouse lifespans especially when fibronectin is overexpressed
Authors: Li Wenjiao , Zou Jing , Yue Fei , Song Kun , Chen Qi , McKeehan Wallace L. , Wang Fen , Xu Guibin , Huang Hai , Yi Jinglin , Liu Leyuan
Published: January 2016

Autophagy is a cellular process that executes the turnover of dysfunctional organelles and misfolded or abnormally aggregated proteins. Microtubule‐associated protein MAP1S interacts with autophagy marker LC3 and positively regulates autophagy flux. LC3 binds with fibronectinmRNA and facilitates its translation. The synthesized fibronectin protein is exported to cell surface to initiate the assembly of fibronectin extracellular matrix. Fibronectin is degraded in lysosomes after it is engulfed into cytosol via endocytosis. Here, we show that defects in MAP1S‐mediated autophagy trigger oxidative stress, sinusoidal dilation, and lifespan reduction. Overexpression of LC3 in wild‐type mice increases the levels of fibronectin and γ‐H2AX, a marker of DNA double‐strand breakage. LC3‐induced fibronectin is efficiently degraded in lysosomes to maintain a balance of fibronectin levels in wild‐type mice so that the mice live a normal term of lifespan. In the LC3 transgenic mice with MAP1S deleted, LC3 enhances the synthesis of fibronectin but the MAP1S depletion causes an impairment of the lysosomal degradation of fibronectin. The accumulation of fibronectin protein promotes liver fibrosis, induces an accumulation of cell population at the G0/G1 stage, and further intensifies oxidative stress and sinusoidal dilatation. The LC3‐induced overexpression of fibronectin imposes stresses on MAP1S‐deficient mice and dramatically reduces their lifespans. Therefore, MAP1S‐mediated autophagy plays an important role in maintaining mouse lifespan especially in the presence of extra amount of fibronectin.
Capital expenditures and firm performance: evidence from a cross‐sectional analysis of stock returns
Authors: Cordis Adriana S. , Kirby Chris
Published: January 2016

Using a simple two‐period model of investment, we show that there should be a nonlinear relation between a firm's investment‐to‐capital ratio and its subsequent stock returns. This prediction finds substantial empirical support. The evidence indicates that the slope of the investment function is negative at low investment levels, close to zero at intermediate investment levels and negative at high investment levels. Our results, which are robust to the use of narrowly‐ and broadly‐defined measures of capital investment, pose a challenge to the hypothesis that the negative cross‐sectional correlation between investment and stock returns is attributable to some sort of overinvestment phenomenon.
Striatal activation and frontostriatal connectivity during non‐drug reward anticipation in alcohol dependence
Authors: Becker Alena , Kirsch Martina , Gerchen Martin Fungisai , Kiefer Falk , Kirsch Peter
Published: January 2016

According to prevailing neurobiological theories of addiction, altered function in neural reward circuitry is a central mechanism of alcohol dependence. Growing evidence postulates that the ventral striatum (VS), as well as areas of the prefrontal cortex, contribute to the increased incentive salience of alcohol‐associated cues, diminished motivation to pursue non‐drug rewards and weakened strength of inhibitory cognitive control, which are central to addiction. The present study aims to investigate the neural response and functional connectivity underlying monetary, non‐drug reward processing in alcohol dependence. We utilized a reward paradigm to investigate the anticipation of monetary reward in 32 alcohol‐dependent inpatients and 35 healthy controls. Functional magnetic resonance imaging was used to measure task‐related brain activation and connectivity. Alcohol‐dependent patients showed increased activation of the VS during anticipation of monetary gain compared with healthy controls. Generalized psychophysiological interaction analyses revealed decreased functional connectivity between the VS and the dorsolateral prefrontal cortex in alcohol dependent patients relative to controls. Increased activation of the VS and reduced frontostriatal connectivity were associated with increased craving. These findings provide evidence that alcohol dependence is rather associated with disrupted integration of striatal and prefrontal processes than with a global reward anticipation deficit.
Influence of a Rotational Speed Modulation System Used With an Implantable Continuous‐Flow Left Ventricular Assist Device on von Willebrand Factor Dynamics
Authors: Naito Noritsugu , Mizuno Toshihide , Nishimura Takashi , Kishimoto Satoru , Takewa Yoshiaki , Eura Yuka , Kokame Koichi , Miyata Toshiyuki , Date Kazuma , Umeki Akihide , Ando Masahiko , Ono Minoru , Tatsumi Eisuke
Published: January 2016

We have developed a rotational speed (RS) modulation system for a continuous‐flow left ventricular assist device (EVAHEART) that can change RS in synchronization with a patient's electrocardiogram. Although EVAHEART is considered not to cause significant acquired von Willebrand syndrome, there remains a concern that the repeated acceleration and deceleration of the impeller may degrade von Willebrand factor (vWF) multimers. Accordingly, we evaluated the influence of our RS modulation system on vWF dynamics. A simple mock circulation was used. The circulation was filled with whole bovine blood (650 mL), and the temperature was maintained at 37 ± 1°C. EVAHEART was operated using the electrocardiogram‐synchronized RS modulation system with an RS variance of 500 rpm and a pulse frequency of 60 bpm (EVA‐RSM; n = 4). The pumps were operated at a mean flow rate of 5.0 ± 0.2 L/min against a mean pressure head of 100 ± 3 mm Hg. The continuous‐flow mode of EVAHEART (EVA‐C; n = 4) and ROTAFLOW (ROTA; n = 4) was used as controls. Whole blood samples were collected at baseline and every 60 min for 6 h. Complete blood counts (CBCs), normalized indexes of hemolysis (NIH), vWF antigen (vWF:Ag), vWF ristocetin cofactor (vWF:Rco), the ratio of vWF:Rco to vWF:Ag (Rco/Ag), and high molecular weight multimers (HMWM) of vWF were evaluated. There were no significant changes in CBCs throughout the 6‐h test period in any group. NIH levels of EVA‐RSM, EVA‐C, and ROTA were 0.0035 ± 0.0018, 0.0031 ± 0.0007, and 0.0022 ± 0.0011 g/100 L, respectively. Levels of vWF:Ag, vWF:Rco, and Rco/Ag did not change significantly during the test. Immunoblotting analysis of vWF multimers showed slight degradation of HMWM in all groups, but there were no significant differences between groups in the ratios of HMWM to low molecular weight multimers, calculated by densitometry. This study suggests that our RS modulation system used with EVAHEART does not have marked adverse influences on vWF dynamics. The low NIH and the absence of significant decreases in CBCs indicate that EVAHEART is hemocompatible, regardless of whether it is operated with the RS modulation system.
Bilaminar Device of Poly(Lactic‐co‐Glycolic Acid)/Collagen Cultured With Adipose‐Derived Stem Cells for Dermal Regeneration
Authors: Domingues Juliana A. , Cherutti Giselle , Motta Adriana C. , Hausen Moema A. , Oliveira Rômulo T.D. , Silva‐Zacarin Elaine C.M. , Barbo Maria Lourdes P. , Duek Eliana A.R.
Published: January 2016

Several materials are commercially available as substitutes for skin. However, new strategies are needed to improve the treatment of skin wounds. In this study, we developed and characterized a new device consisting of poly(lactic‐co‐glycolic acid) (PLGA) and collagen associated with mesenchymal stem cells derived from human adipose tissue. To develop the bilaminar device, we initially obtained a membrane of PLGA by dissolving the copolymer in chloroform and then produced a collagen type I scaffold by freeze‐drying. The materials were characterized physically by gel permeation chromatography, scanning electron microscopy, and mass loss. Biological activity was assessed by cell proliferation assay. A preliminary study in vivo was performed with a pig model in which tissue regeneration was assessed macroscopically and histologically, the commercial device Integra being used as a control. The PLGA/collagen bilaminar material was porous, hydrolytically degradable, and compatible with skin growth. The polymer complex allowed cell adhesion and proliferation, making it a potentially useful cell carrier. In addition, the transparency of the material allowed monitoring of the lesion when the dressings were changed. Xenogeneic mesenchymal cells cultured on the device (PLGA/collagen/ASC) showed a reduced granulomatous reaction to bovine collagen, down‐regulation of α‐SMA, enhancement in the number of neoformed blood vessels, and collagen organization as compared with normal skin; the device was superior to other materials tested (PLGA/collagen and Integra) in its ability to stimulate the formation of new cutaneous tissue.
GOVERNANCE OF PRODUCTION CO‐OPERATIVES IN RUSSIAN AGRICULTURE
Authors: NILSSON Jerker , GOLOVINA Svetlana , HESS Sebastian , WOLZ Axel
Published: January 2016

Many Soviet kolkhozy and sovkhozy were transformed into agricultural production co‐operatives, because the farm workers would have had large transaction costs in any other type of organization. These co‐operatives still hold a strong market position. This study explores the hypothesis that this market strength could be due to low governance costs, obtained through strong manager power. As managers want the co‐operative to survive, they make limited investments in the co‐operative and pay low wages. The members, however, do not consider this to be problematic. They appreciate the community within the village, their private plots of land and the co‐operative's services. Hence the existence of the co‐operatives is not threatened.
EMPLOYMENT STABILIZATION INSIDE FIRMS: AN EMPIRICAL INVESTIGATION OF WORKER COOPERATIVES
Authors: NAVARRA Cecilia
Published: January 2016

There is evidence that worker cooperatives provide a greater stabilization of employment compared to capital‐managed firms. While the reasons of this behaviour can be ascribed to their property and governance structure, less is known of the tools to put it into practice. I discuss two possible ways to guarantee employment insurance: by letting wages fluctuate, or by accumulating reinvested profits into an income stabilizing fund that copes with downturns without firing and without reducing wages. In this second case, I find out that asset locks play a wage smoothing role. This may explain the large share of profits that are reinvested in this indivisible and not appropriable fund. I provide evidence for this mechanism by means of original data at the firm level and of first‐hand collected survey data at the individual level on risk perception in a sample of Italian cooperatives.
THE FORECASTING PERFORMANCE OF SETAR MODELS: AN EMPIRICAL APPLICATION
Authors: Boero Gianna , Lampis Federico
Published: January 2016

The aim of this paper is to evaluate the forecasting performance of SETAR models with an application to the Industrial Production Index (IPI) of four major European countries over a period which includes the last Great Recession. Both point and interval forecasts are considered at different horizons against those obtained from two linear models. We follow the approach suggested by Teräsvirta et al. (2005) according to which a dynamic specification may improve the forecast performance of the nonlinear models with respect to the linear models. We re‐specify the models every twelve months and we find that the advantages of this procedure are particularly evident in the forecast rounds immediately following the re‐specification.
Contribution of adrenomedullin to the switch of G protein‐coupled μ‐opioid receptors from Gi to Gs in the spinal dorsal horn following chronic morphine exposure in rats
Authors: Wang Dongmei , Zeng Juan , Li Qi , Huang Jianzhong , Couture Réjean , Hong Yanguo
Published: January 2016

Background and Purpose

Chronic exposure to morphine increases spinal adrenomedullin (AM) bioactivity resulting in the development and maintenance of morphine tolerance. This study investigated the possible involvement of AM in morphine‐evoked alteration in μ‐opioid receptor‐coupled G proteins.

Experimental Approach

Agents were administered intrathecally (i.t.) in rats. Nociceptive behaviours and cumulative dose–response of morphine analgesia were assessed. Neurochemicals in the spinal dorsal horn were assayed by immunoprecipitation, Western blot analysis and ELISA.

Key Results

Intrathecal injection of AM (8 μg) for 9 days decreased and increased the levels of μ receptor‐coupled Gi and Gs proteins respectively. Morphine stimulation (5 μg) after chronic treatment with AM also induced an increase in cAMP production in the spinal dorsal horn. Co‐administration of the selective AM receptor antagonist AM22–52 inhibited chronic morphine‐evoked switch of G protein‐coupled μ receptor from Gi to Gs. Chronic exposure to AM increased the phosphorylation of cAMP‐responsive element‐binding protein (CREB) and ERK. Co‐administration of the PKA inhibitor H‐89 (5 μg) or MEK1 inhibitor PD98059 (1 μg) reversed the AM‐induced thermal/mechanical hypersensitivity, decline in morphine analgesic potency, switch of G protein‐coupled μ receptor and increase in cAMP.

Conclusions and Implications

The present study supports the hypothesis that an increase in AM activity in the spinal dorsal horn contributes to the switch of the μ receptor‐coupled G protein from Gi to Gs protein via the activation of cAMP/PKA/CREB and ERK signalling pathways in chronic morphine use.
The Warburg effect and drug resistance
Authors: Bhattacharya Bhaskar , Mohd Omar Mohd Feroz , Soong Richie
Published: January 2016

The Warburg effect describes the increased utilization of glycolysis rather than oxidative phosphorylation by tumour cells for their energy requirements under physiological oxygen conditions. This effect has been the basis for much speculation on the survival advantage of tumour cells, tumourigenesis and the microenvironment of tumours. More recently, studies have begun to reveal how the Warburg effect could influence drug efficacy and how our understanding of tumour energetics could be exploited to improve drug development. In particular, evidence is emerging demonstrating how better modelling of the tumour metabolic microenvironment could lead to a better prediction of drug efficacy and the identification of new combination strategies. This review will provide details of the current understanding of the complex interplay between glucose metabolism and pharmacology and discuss opportunities for utilizing the Warburg effect in future drug development.
Single administration of recombinant IL‐6 restores the gene expression of lipogenic enzymes in liver of fasting IL‐6‐deficient mice
Authors: Gavito AL , Cabello R , Suarez J , Serrano A , Pavón F J , Vida M , Romero M , Pardo V , Bautista D , Arrabal S , Decara J , Cuesta AL , Valverde A M , Rodríguez de Fonseca F , Baixeras E
Published: January 2016

Background and Purpose

Lipogenesis is intimately controlled by hormones and cytokines as well as nutritional conditions. IL‐6 participates in the regulation of fatty acid metabolism in the liver. We investigated the role of IL‐6 in mediating fasting/re‐feeding changes in the expression of hepatic lipogenic enzymes.

Experimental Approach

Gene and protein expression of lipogenic enzymes were examined in livers of wild‐type (WT) and IL‐6‐deficient (IL‐6−/−) mice during fasting and re‐feeding conditions. Effects of exogenous IL‐6 administration on gene expression of these enzymes were evaluated in vivo. The involvement of STAT3 in mediating these IL‐6 responses was investigated by using siRNA in human HepG2 cells.

Key Results

During feeding, the up‐regulation in the hepatic expression of lipogenic genes presented similar time kinetics in WT and IL‐6−/− mice. During fasting, expression of lipogenic genes decreased gradually over time in both strains, although the initial drop was more marked in IL‐6−/− mice. Protein levels of hepatic lipogenic enzymes were lower in IL‐6−/− than in WT mice at the end of the fasting period. In WT, circulating IL‐6 levels paralleled gene expression of hepatic lipogenic enzymes. IL‐6 administration in vivo and in vitro showed that IL‐6‐mediated signalling was associated with the up‐regulation of hepatic lipogenic enzyme genes. Moreover, silencing STAT3 in HepG2 cells attenuated IL‐6 mediated up‐regulation of lipogenic gene transcription levels.

Conclusions and Implications

IL‐6 sustains levels of hepatic lipogenic enzymes during fasting through activation of STAT3. Our findings indicate that clinical use of STAT3‐associated signalling cytokines, particularly against steatosis, should be undertaken with caution.
Metformin inhibits the prometastatic effect of sorafenib in hepatocellular carcinoma by upregulating the expression of TIP30
Authors: Guo Zhigui , Cao Manqing , You Abin , Gao Junrong , Zhou Hongyuan , Li Huikai , Cui Yunlong , Fang Feng , Zhang Wei , Song Tianqiang , Li Qiang , Zhu Xiaolin , Sun Huichuan , Zhang Ti
Published: January 2016

We previously found that a low dose of sorafenib had a prometastatic effect on hepatocellular carcinoma (HCC), which was caused by downregulation of TIP30 expression. More recently, metformin has been shown to have potential as a preventive and therapeutic agent for different cancers, including HCC. This study evaluated whether the combination of sorafenib and metformin is sufficient to revert the expression of TIP30, thereby simultaneously reducing lung metastasis and improving survival. Our data show that the combination of sorafenib and metformin inhibits proliferation and invasion in vitro, prolongs median survival, and reduces lung metastasis of HCC in vivo. This effect is closely associated with the upregulation of TIP30, partly through activating AMP‐activated protein kinase. Thioredoxin, a prometastasis factor, is negatively regulated by TIP30 and plays an essential role during the process of HCC metastasis. Overall, our results suggest that metformin might be a potent enhancer for the treatment of HCC by using sorafenib.
Significant intratumoral heterogeneity of human epidermal growth factor receptor 2 status in gastric cancer: A comparative study of immunohistochemistry, FISH, and dual‐color in situ hybridization
Authors: Kanayama Kazuki , Imai Hiroshi , Yoneda Misao , Hirokawa Yoshifumi S. , Shiraishi Taizo
Published: January 2016

The assessment of human epidermal growth factor receptor 2 (HER2) status is crucial for selecting patients with gastric cancer who may benefit from HER2‐targeted therapy. Accurate assessment using biopsy specimens is important for patients with advanced‐stage cancer. Intratumoral heterogeneity of HER2, however, is a major challenge in HER2 testing. Here, we aimed to examine whether assessment of HER2 status could be accurately carried out with currently used methods, namely, immunohistochemistry (IHC), FISH, and dual‐color in situ hybridization (DISH). Human epidermal growth factor receptor 2 status was evaluated in 108 biopsy tissues from patients with gastric adenocarcinoma and 70 matched surgical specimens by IHC, FISH, and DISH; HER2 amplification was detected in 11 (10.2%) out of 108 biopsy specimens. The IHC and FISH results were well correlated, and FISH and DISH results were consistent for all cases. The overall concordance rate of HER2 status between biopsy tissues and surgical specimens was 91.4%. All six discordant cases were false negative on biopsy; of these cases, five showed HER2 heterogeneity on surgical resection. Assessment of the HER2 status of biopsy tissues could predict the status of the whole tumor; however, a proportion of these cases may be discordant because of intratumoral heterogeneity.
Volatile organic compounds as new biomarkers for colorectal cancer: a review
Authors: Di Lena M. , Porcelli F. , Altomare D. F.
Published: January 2016

Analysis of the volatile part of the metabolome (volatile organic compounds, VOC) present in the gas phase of excreted materials is a promising new screening tool for several cancers, including colorectal cancer (CRC). The VOC signature can reflect health status, like a ‘fingerprint’, and can be modified in several diseases. Technical difficulties still limit the widespread use of VOC analysis in the clinical setting, but this approach has already been applied successfully in the diagnosis of CRC. The present study reviews the available data on VOC present in the headspace (the gaseous constituents of a closed space above a liquid or solid) of blood, urine, faeces and breath as a potential screening tool for CRC. A systematic electronic literature search was conducted in PubMed, Scirus and Google using the following keywords: Metabolomic, Volatile Organic Compounds (VOC), Electronic‐nose and Colorectal Cancer. Only articles published in English between 2000 and 2015 were selected and these were independently checked by two of the authors. Ten papers describing the reliability of VOC analysis in breath and faeces, blood and urine were selected; all indicated good reliability in detecting CRC. The use of different substrates and different analytical platforms has led to the identification of different patterns of VOC. The reliability of a metabolomic approach as a noninvasive biomarker for use in CRC screening is supported by this review despite several limitations due to the number of patients included in each study, the different analytical platforms and biological materials used and different VOC identified.
Native versus non‐native invasions: similarities and differences in the biodiversity impacts of Pinus contorta in introduced and native ranges
Authors: Taylor Kimberley T. , Maxwell Bruce D. , Pauchard Aníbal , Nuñez Martin A. , Rew Lisa J.
Published: January 2016

Aim

To determine whether one of the most invasive pine species introduced to the Southern Hemisphere, Pinus contorta, has changed plant species richness, composition, diversity, and litter depth where it has invaded into native open forest, shrub steppe and grassland communities and to assess whether changes were similar in its native and introduced ranges.

Location

Río Negro Province, Argentina; Aysén and Araucanía Regions, Chile; Greater Yellowstone Ecosystem, USA.

Methods

We measured changes in plant species richness, species composition and cover, diversity, and litter depth associated with increasing P. contorta tree cover along the invasion front at three sites in the introduced range (Argentina and Chile) and one in the native range (Montana, USA).

Results

Plant species richness and cover generally declined with increasing P. contorta canopy cover, at similar rates in both the introduced and native ranges. However, plant cover was not affected by P. contorta in a forested setting in the introduced range. P. contorta invasion explained more of the decline in species richness in the introduced than native range. Native species composition changed more strongly across the invasion gradient in the introduced than native range. Litter depth increased more rapidly with P. contorta cover in the native than introduced range.

Main conclusions

Our results highlight the potential of pines to alter plant communities whether encroaching from forests in the native range or from plantations in the introduced range. Species richness and plant cover declined in both settings; however, individual species abundance and species composition were more impacted in the introduced range than in the native range. We suggest that invading trees have a greater capacity to cause ecological impacts in their introduced than in their native range, particularly where they represent a novel life‐form.
Mixture or mosaic? Genetic patterns in UK grey squirrels support a human‐mediated ‘long‐jump’ invasion mechanism
Authors: Signorile A. L. , Lurz P. W.W. , Wang J. , Reuman D. C. , Carbone C.
Published: January 2016

Aim

Clarifying whether multiple introductions of a species remain relatively isolated or merge and interbreed is essential for understanding the dynamics of invasion processes. Multiple introductions from different sources can result in a mixture of genetically distinct populations, increasing the total genetic diversity. This mixing can resolve the ‘genetic paradox’, whereby in spite of the relatively small numbers of introduced individuals, the augmented diversity due to this mixing increases adaptability and the ability of the species to spread in new environments. Here, we aim to assess whether the expansion of a successful invader, the Eastern grey squirrel, was partly driven by the merger of multiple introductions and the effects of such a merger on diversity.

Location

UK, Ireland.

Methods

We analysed the genetic variation at 12 microsatellite loci of 381 individuals sampled from one historical and 14 modern populations of grey squirrels.

Results

Our data revealed that current UK population structure resembles a mosaic, with minimal interpopulation mixing and each element reflecting the genetic make‐up of historic introductions. The genetic diversity of each examined population was lower than a US population or a historical UK population. Numbers of releases in a county did not correlate with county‐level genetic diversity. Inbreeding coefficients remain high, and effective population sizes remain small.

Main conclusions

Our results support the conclusion that rapid and large‐scale expansion in this species in the UK was not driven by a genetic mixing of multiple introduced populations with a single expansion front, but was promoted by repeated translocations of small propagules. Our results have implications for the management of grey squirrels and other invasive species and also demonstrate how invaders can overcome the genetic paradox, if spread is facilitated by human‐mediated dispersal.
Functional connectivity of brain regions for self‐ and other‐evaluation in children, adolescents and adults with autism
Authors: Burrows Catherine A. , Laird Angela R. , Uddin Lucina Q.
Published: January 2016

Developing strong ties between oneself and others lays the foundation for developing social competence. Neuroimaging studies have consistently identified specific cortical midline regions activated during evaluative judgments about the self and others. Individuals with autism spectrum disorder (ASD) process self‐relevant information differently from their peers, both behaviorally and at the neural level. We compared resting‐state functional connectivity (rsFC) of regions involved in self‐referential (e.g. medial prefrontal cortex; mPFC) and other‐referential (e.g. posterior cingulate cortex; PCC) processing between neurotypical individuals and individuals with ASD in three age cohorts using regions of interest (ROIs) identified through an activation likelihood estimation meta‐analysis. Typically developing children demonstrated greater connectivity within the midline self‐ and other‐referential networks compared with age‐matched children with ASD. No group differences in rsFC of mPFC or PCC emerged between typically developing adolescents and adolescents with ASD. Neurotypical adults exhibited stronger rsFC of the PCC with orbitofrontal cortex compared with adults with ASD. Developmental differences in functional connectivity between areas underlying self‐ and other‐referential thought may explain altered developmental trajectories in the understanding of self and others in individuals with ASD.
The roles of juvenile hormone and biogenic amines on pheromone response plasticity and diapause termination in male Caloptilia fraxinella
Authors: Lemmen Joelle K. , Evenden Maya L.
Published: January 2016

In insects that exhibit a period of delayed reproduction, the timing of mating and reproduction is controlled by environmental conditions that regulate endogenous factors such as hormones and biogenic amines (BAs). Caloptilia fraxinella (Ely) (Lepidoptera: Gracillariidae) undergoes a 9‐month reproductive diapause from adult eclosion in the summer until diapause termination the following spring when adults mate. Male response to female sex pheromone is plastic, and is most acute when moths are reproductively active. The aim of this study is to further elucidate the mechanisms involved in the regulation of male response to pheromone in C. fraxinella, and to test whether the application of BAs with and without a juvenile hormone analogue (JHA) to males in different physiological states impacts pheromone responsiveness, as measured by electroantennogram and wind tunnel bioassays. Treatment of male C. fraxinella in reproductive diapause with one application of a JHA induces the highest subsequent pheromone response in the fall, but does not alter pheromone response earlier in reproductive diapause in the summer. The JHAs methoprene and pyriproxyfen similarly enhance pheromone response in the fall. Treatment with methoprene alone or in combination with one of the BAs octopamine, dopamine or serotonin increases male pheromone responsiveness in the fall. The increase in pheromone response can be attributed to methoprene only, as treatment with any of the BAs alone does not enhance male response to pheromone. Biogenic amine treatment lowers male responsiveness to pheromone in some experiments, indicating that there may be a role for BAs in maintaining low pheromone response during reproductive diapause in this species.
Orexin/hypocretin neuron activation is correlated with alcohol seeking and preference in a topographically specific manner
Authors: Moorman David E. , James Morgan H. , Kilroy Elisabeth A. , Aston‐Jones Gary
Published: January 2016

Orexin (ORX) (also known as hypocretin) neurons are located exclusively in the posterior hypothalamus, and are involved in a wide range of behaviours, including motivation for drugs of abuse such as alcohol. Hypothalamic subregions contain functionally distinct populations of ORX neurons that may play different roles in regulating drug‐motivated and alcohol‐motivated behaviours. To investigate the role of ORX neurons in ethanol (EtOH) seeking, we measured Fos activation of ORX neurons in rats following three different measures of EtOH seeking and preference: (i) context‐induced reinstatement, or ABA renewal; (ii) cue‐induced reinstatement of extinguished responding for EtOH; and (iii) a home cage task in which preference for EtOH (vs. water) was measured in the absence of either reinforcer. We found significant activation of ORX neurons in multiple subregions across all three behavioural tests. Notably, ORX neuron activation in the lateral hypothalamus correlated with the degree of seeking in context reinstatement and the degree of preference in home cage preference testing. In addition, Fos activation in ORX neurons in the dorsomedial hypothalamic and perifornical areas was correlated with context and home cage seeking/preference, respectively. Surprisingly, we found no relationship between the degree of cue‐induced reinstatement and ORX neuron activation in any region, despite robust activation overall during reinstatement. These results demonstrate a strong relationship between ORX neuron activation and EtOH seeking/preference, but one that is differentially expressed across ORX field subregions, depending on reinstatement modality.
Passing up the Job: The Role of Gendered Organizations and Families in the Entrepreneurial Career Process
Authors: Thébaud Sarah
Published: January 2016

This article theorizes and evaluates the relationship between inflexible organizational practices, family factors, and gendered pathways into entrepreneurship. Using novel survey data collected by the Harris Poll, I evaluate how a decision to pass up a job that lacks flexibility is associated with self–employment, and examine how this relationship varies by gender, family status, and educational attainment. Findings suggest that passing up a job is associated with women's, but not men's, self–employment. Moreover, motherhood and a spouse's employment status predict women's self–employment, but only if they have sacrificed a job opportunity.
Mobility and Entrepreneurship: Evaluating the Scope of Knowledge–Based Theories of Entrepreneurship
Authors: Frederiksen Lars , Wennberg Karl , Balachandran Chanchal
Published: January 2016

Knowledge–based theories of entrepreneurship infer transfer of knowledge from the effect of labor mobility on entrepreneurial entry. Yet, simple selection or situational mechanisms that do not imply knowledge transfer may influence entrepreneurial entry in similar ways. We argue that the extent to which such alternative mechanisms operate, labor mobility predicts entry but not subsequent performance for entrepreneurs. Analyses of matched employee–employer data from Sweden suggest that high rates of geographical and industry mobility increase individuals’ likelihood of entrepreneurial entry but have no effects on their entrepreneurial performance. This indicates that the relationship between labor mobility and entrepreneurial entry do not necessarily imply knowledge transfer.
Effects of experimental fuel additions on fire intensity and severity: unexpected carbon resilience of a neotropical forest
Authors: Brando Paulo M. , Oliveria‐Santos Claudinei , Rocha Wanderley , Cury Roberta , Coe Michael T.
Published: January 2016

Global changes and associated droughts, heat waves, logging activities, and forest fragmentation may intensify fires in Amazonia by altering forest microclimate and fuel dynamics. To isolate the effects of fuel loads on fire behavior and fire‐induced changes in forest carbon cycling, we manipulated fine fuel loads in a fire experiment located in southeast Amazonia. We predicted that a 50% increase in fine fuel loads would disproportionally increase fire intensity and severity (i.e., tree mortality and losses in carbon stocks) due to multiplicative effects of fine fuel loads on the rate of fire spread, fuel consumption, and burned area. The experiment followed a fully replicated randomized block design (N = 6) comprised of unburned control plots and burned plots that were treated with and without fine fuel additions. The fuel addition treatment significantly increased burned area (+22%) and consequently canopy openness (+10%), fine fuel combustion (+5%), and mortality of individuals ≥5 cm in diameter at breast height (dbh; +37%). Surprisingly, we observed nonsignificant effects of the fuel addition treatment on fireline intensity, and no significant differences among the three treatments for (i) mortality of large trees (≥30 cm dbh), (ii) aboveground forest carbon stocks, and (iii) soil respiration. It was also surprising that postfire tree growth and wood increment were higher in the burned plots treated with fuels than in the unburned control. These results suggest that (i) fine fuel load accumulation increases the likelihood of larger understory fires and (ii) single, low‐intensity fires weakly influence carbon cycling of this primary neotropical forest, although delayed postfire mortality of large trees may lower carbon stocks over the long term. Overall, our findings indicate that increased fine fuel loads alone are unlikely to create threshold conditions for high‐intensity, catastrophic fires during nondrought years.
The effectiveness of conically shaped compared with cylindrically shaped interdental brushes – a randomized controlled clinical trial
Authors: Larsen HC , Slot DE , Van Zoelen C , Barendregt DS , Van der Weijden GA
Published: January 2016

Aim

The purpose of this study was to compare the effectiveness of conically shaped versus cylindrically shaped interdental brushes (IDB) in patients receiving supportive periodontal therapy.

Materials and methods

Periodontal maintenance patients volunteered to be enrolled into this randomized controlled examiner‐blind parallel study. At baseline and after 3 months, plaque scores, bleeding upon pocket probing scores and probing pocket depth (PPD) were assessed. The type of IDB (conical or cylindrical) was randomly assigned to each patient and individual instruction was provided regarding the method of use and the appropriate size. Only those approximal sites that had sufficient space for the IDB were eligible, and for those sites the data were analysed separately. Analyses were performed for all eligible approximal surfaces and a sub‐analysis was performed for vestibular and lingual surfaces.

Results

In total, 51 participants attended the baseline and the 3‐month clinical appointments. Overall, there was no difference between conical and cylindrical IDBs. However, the conical IDB showed significantly higher plaque and bleeding scores at the lingual approximal sites. The cause of this difference was an increase in plaque and bleeding scores compared with baseline. With respect to the PPD, no difference between the IDBs was observed.

Conclusion

Within the limitations of this experiment, the conical IDBs are less effective than cylindrical IDBs with respect to lingual approximal plaque removal. Thus, in patients receiving supportive periodontal therapy, the cylindrical shape should be the first choice of IDB to obtain and maintain gingival health around natural teeth.
Immigrant Bilingualism in Spain: An Asset or a Liability?
Authors: Medvedeva Maria , Portes Alejandro
Published: January 2016

This study contributes to the ongoing debate about bilingual advantage and examines whether bilingual immigrant youths fare better, as well as, or worse academically than the matching group of monolinguals. Using data from Spain, where close to half of immigrants speak Spanish as their native language, we found no evidence of costs of bilingualism: bilingual youths did benefit from their linguistic skills. Their advantage, however, manifested itself not uniformly across discrete outcomes, but in a direct trajectory toward higher educational attainment. Bilingualism neutralized the possible negative effect of ethnic origins and extended the positive effect of high parental ambition. Implications for theory and practice are discussed.
Current status of palliative care services in Indonesia: a literature review
Authors: Rochmawati Erna , Wiechula Rick , Cameron Kate
Published: January 2016

Aim

To review healthcare literature in relation to the provision of palliative care in Indonesia and to identify factors that may impact on palliative care development.

Background

People living with life‐limiting illness benefit from access to palliative care services to optimize quality of life. Palliative care services are being expanded in developing countries but in Indonesia such services are in their infancy with many patients with life‐limiting illnesses having access to appropriate health care compromised.

Methods

Relevant healthcare databases including CINAHL, PubMed, Science Direct and Scopus were searched using the combinations of search terms: palliative care, terminal care, end‐of‐life care, Indonesia and nursing. A search of grey literature including Internet sites was also carried out.

Results

Nine articles were included in the review. Facilitating factors supporting the provision of palliative care included: a culture of strong familial support, government policy support, volunteering and support from regional organizations. Identified barriers to palliative care provision were a limited understanding of palliative care among healthcare professionals, the challenging geography of Indonesia and limited access to opioid medications.

Conclusions

There are facilitators and barriers that currently impact on the development of palliative care in Indonesia. Strategies that can be implemented to improve palliative care include training of nurses and doctors in the primary care sector, integrating palliative care in undergraduate medical and nursing curriculum and educating family and community about basic care. Nurses and doctors who work in primary care can potentially play a role in supporting and educating family members providing direct care to patients with palliative needs.
Nitrogen Sustains Seed Yield of Quinoa Under Intermediate Drought
Authors: Alandia G. , Jacobsen S.‐E. , Kyvsgaard N. C. , Condori B. , Liu F.
Published: January 2016

Quinoa (Chenopodium quinoa Willd.) is a promising crop for food security in dry areas. Studies have been conducted to define nitrogen (N) fertilization levels and to understand the responses of quinoa to drought, but little is known about the response of this crop to N fertilization under drought stress. The aim of this study was to investigate whether N fertilization could improve quinoa yield and physiology under limited water. A greenhouse experiment was carried out with quinoa grown at four N fertilization levels (0, 0.2, 0.4 and 0.6 g N pot−1) and two watering treatments (progressive drought and full irrigation; 10 and 98 % of pot water holding capacity, respectively). Results of this experiment showed that N may confer a certain degree of drought tolerance to quinoa as seed quality and yield of N‐fertilized plants were not affected by drought stress. Responses such as faster stomatal closure, reduced leaf water potential, higher leaf abscisic acid (ABA) concentration and particularly an improved N remobilization in N‐fertilized plants may have played a role in sustaining seed yield in the drought‐stressed treatment. These results under controlled conditions serve as a basis to elucidate drought tolerance mechanisms activated with N fertilization and to define the use of N in management practices under semi‐arid environments.
Evaluation of the internal and external responsiveness of the Pressure Ulcer Scale for Healing (PUSH) tool for assessing acute and chronic wounds
Authors: Choi Edmond P.H. , Chin Weng Yee , Wan Eric Y.F. , Lam Cindy L.K.
Published: January 2016

Aim

To examine the internal and external responsiveness of the Pressure Ulcer Scale for Healing (PUSH) tool for assessing the healing progress in acute and chronic wounds.

Background

It is important to establish the responsiveness of instruments used in conducting wound care assessments to ensure that they are able to capture changes in wound healing accurately over time.

Design

Prospective longitudinal observational study.

Method

The key study instrument was the PUSH tool. Internal responsiveness was assessed using paired t‐testing and effect size statistics. External responsiveness was assessed using multiple linear regression. All new patients with at least one eligible acute or chronic wound, enrolled in the Nurse and Allied Health Clinic‐Wound Care programme between 1 December 2012 – 31 March 2013 were included for analysis (N = 541).

Results

Overall, the PUSH tool was able to detect statistically significant changes in wound healing between baseline and discharge. The effect size statistics were large. The internal responsiveness of the PUSH tool was confirmed in patients with a variety of different wound types including venous ulcers, pressure ulcers, neuropathic ulcers, burns and scalds, skin tears, surgical wounds and traumatic wounds. After controlling for age, gender and wound type, subjects in the ‘wound improved but not healed’ group had a smaller change in PUSH scores than those in the ‘wound healed’ group. Subjects in the ‘wound static or worsened’ group had the smallest change in PUSH scores. The external responsiveness was confirmed.

Conclusion

The internal and external responsiveness of the PUSH tool confirmed that it can be used to track the healing progress of both acute and chronic wounds.