bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Hemodialysis on Electrocardiographic Parameters
Authors: Astan Ramazan , Akpinar Ibrahim , Karan Adnan , Kacmaz Fehmi , Sokmen Erdogan , Baysal Erkan , Ozeke Ozcan , Selçuk Mehmet Timur
Published: September 2014

Background

Cardiovascular complications are the leading causes of premature deaths in hemodialysis patients. Due to rapid changes in volume and electrolyte concentration following dialysis, the some electrocardiographic (ECG) changes or arrhythmias might be seen.

Objective

To investigate the acute effects of hemodialysis on the ECG parameters in patients with chronic end‐stage renal disease (ESRD).

Method

We included the consecutive ESRD patients who underwent a hemodialysis. Before and after hemodialysis, some 12 lead ECG parameters were analyzed by two different cardiologists by using electronic digital caliper device.

Results

A total of 62 patients (mean 52 ± 15 years; 65% male) with ESRD undergoing hemodialysis were recruited to the study. P‐wave amplitude, QRS amplitude, QRS duration, QTc dispersion, the sum of amplitudes in V1S + V5R derivations, total QRS amplitude, and duration were significantly greater in posthemodialysis patients compared to the prehemodialysis ones. However, T‐wave amplitude and QTc duration were significantly lower in posthemodialysis patients.

Conclusion

The ECG changes including prolangated QRS and increased QTc interval after hemodialysis should be kept in mind and assessed carefully in ESRD patients. Prolongation of these parameters may prove to be a further noninvasive marker of susceptibility to ventricular arrhythmias.
Clostridium colitis: challenges in diagnosis and treatment
Authors: Buxey Kenneth N. , Sia Chris , Bell Stephen , Wale Roger , Wein Daniel , Warrier Satish K.
Published: September 2014

Background

Clostridium difficile infection (CDI) has been reported to occur with increasing frequency and with more severe presentations being encountered. This article presents data from The Alfred Hospital highlighting the increased incidence, the increased severity and the broader clinical presentations observed. A case series highlights a variety of clinical scenarios that provided diagnostic and management challenges. We additionally describe a novel form of treatment for fulminant colitis.

Methods

A retrospective review of C. difficile toxin (CDT)‐positive and culture‐positive cases was performed at The Alfred Hospital (2010–2012). Six cases are then presented as a case series to highlight the broad and atypical types of presentations one may encounter. Finally, a novel method for managing fulminant colitis operatively is presented.

Results

A fourfold increase in cases of toxin‐positive and culture‐positive cases was noted over the initial 14 months of the period of analysis, the rate of cases detected then plateaued. This increase could not be explained by increased testing being undertaken. It is also not associated with increased usage of antibiotics nor with increased patient numbers being treated.

Conclusion

CDI can present in various clinical forms. In our hospital, the number of cases of toxin‐positive and culture‐positive detection is increasing. A low threshold is required to identify and adequately treat patients with CDI. Fulminant colitis can be managed successfully with the creation of a diverting loop ileostomy, colonic washout and subsequent antegrade colonic vancomycin enemas.
Understanding long‐term effects of topsoil removal in peatlands: overcoming thresholds for fen meadows restoration
Authors: Klimkowska Agata , van der Elst David J.D. , Grootjans Albert P.
Published: September 2014

Questions

What are the long‐term results of fen meadow restoration after topsoil removal on peatlands? What are the causes of slow fen‐meadow vegetation recovery on peat soils after topsoil removal?

Location

Drentsche Aa Nature Reserve (53°00′49″N, 6°37′46″E) in the northeast Netherlands, with extensive natural and partially restored fen meadows (ca. 10,000 ha).

Methods

Restoration measures consisted of removal of acidified and fertilized topsoil and improvement of local hydrology by blocking or removing drainage ditches. The effects of shallow (20 cm) and deep (40 cm) topsoil removal were compared. We monitored vegetation changes after restoration measures in permanent plots over a 13‐yr period, and analysed changes in species composition over time with ordination techniques (multivariate analysis: PCA and RDA). Soil conditions over time were analysed using repeated measures ANOVA.

Results

The vegetation and environment shifted over time in response to restoration. At first the vegetation stagnated in a species‐poor phase for 5 yr, but eventually fen‐meadow species re‐established. At the end of the observation period, after 14 yr, the vegetation after both shallow and deep peat removal was similar. Soil acidification occurred immediately after topsoil removal (within the first 2–3 yr) due to pyrite oxidation when the soil was exposed to air after site excavation and the peat was temporarily desiccated.

Conclusions

We found poor re‐establishment of fen‐meadow vegetation and persistence of species‐poor communities during the first 5 yr after topsoil removal, probably resulting from internal soil acidification. After further rewetting, a rapid shift towards the target community composition was observed. The positive shift in development of fen‐meadow vegetation probably occurred due to increased groundwater discharge after successful hydrological measures were applied. Appropriate hydrological conditions (strong discharge of groundwater) are important for the success of restoration of these fen meadows, especially if pyrite is present in shallow soil layers.
In vitro testing for diagnosis of idiosyncratic adverse drug reactions: Implications for pathophysiology
Authors: Elzagallaai Abdelbaset A. , Rieder Michael J.
Published: September 2014

Idiosyncratic drug reactions (IDRs) represent a major health problem, as they are unpredictable, often severe and can be life threatening. The low incidence of IDRs makes their detection during drug development stages very difficult causing many post‐marketing drug withdrawals and black box warnings. The fact that IDRs are always not predictable based on the drug's known pharmacology and have no clear dose–effect relationship with the culprit drug renders diagnosis of IDRs very challenging, if not impossible, without the aid of a reliable diagnostic test. The drug provocation test (DPT) is considered the gold standard for diagnosis of IDRs but it is not always safe to perform on patients. In vitro tests have the advantage of bearing no potential harm to patients. However, available in vitro tests are not commonly used clinically because of lack of validation and their complex and expensive procedures. This review discusses the current role of in vitro diagnostic testing for diagnosis of IDRs and gives a brief account of their technical and mechanistic aspects. Advantages, disadvantages and major challenges that prevent these tests from becoming mainstream diagnostic tools are also discussed here.
Factorial structure of the ‘ToM Storybooks’: A test evaluating multiple components of Theory of Mind
Authors: Bulgarelli Daniela , Testa Silvia , Molina Paola
Published: September 2014

This study examined the factorial structure of the Theory of Mind (ToM) Storybooks, a comprehensive 93‐item instrument tapping the five components in Wellman's model of ToM (emotion recognition, understanding of desire and beliefs, ability to distinguish between physical and mental entities, and awareness of the link between perception and knowledge). A sample of 681 three‐ to eight‐year‐old Italian children was divided into three age groups to assess whether factorial structure varied across different age ranges. Partial credit model analysis was applied to the data, leading to the empirical identification of 23 composite variables aggregating the ToM Storybooks items. Confirmatory factor analysis was then conducted on the composite variables, providing support for the theoretical model. There were partial differences in the specific composite variables making up the dimensions for each of the three age groups. A single test evaluating distinct dimensions of ToM is a valuable resource for clinical practice which may be used to define differential profiles for specific populations.
Ureteroscopy for stone disease in the paediatric population: a systematic review
Authors: Ishii Hiro , Griffin Stephen , Somani Bhaskar K.
Published: September 2014

The aim of the present review was to look at the role of ureteroscopy (URS) for treatment of paediatric stone disease. We conducted a systematic review using studies identified by a literature search between January 1990 and May 2013. All English‐language articles reporting on a minimum of 50 patients aged ≤18 years treated with URS for stone disease were included. Two reviewers independently extracted the data from each study. A total of 14 studies (1718 procedures) were reported in patients with a mean (range) age of 7.8 (0.25–18.0) years. The mean (range) stone burden was 9.8 (1–30) mm and the mean (range) stone‐free rate (SFR) 87.5 (58–100)% with initial therapeutic URS. The majority of these stones were in the ureter (n = 1427, 83.4%). There were 180 (10.5%) Clavien I–III complications and 38 cases (2.2%) where there was a failure to complete the initial ureteroscopic procedure and an alternative procedure was performed. To assess the impact of age on failure rate and complications, studies were subcategorized into those that included children with either a mean age <6 years (four studies, 341 procedures) or a mean age >6 years. (10 studies, 1377 procedures). A higher failure rate (4.4 vs 1.7%) and a higher complication rate (24.0 vs 7.1%) were observed in children whose mean age was <6 years. URS for paediatric stone disease is a relatively safe procedure with a reasonably good SFR, but there seems to be a higher failure and complication rate in children aged <6 years.
Welcome Interferences: Dealing with Obstacles Promotes Creative Thought in Goal Pursuit
Authors: Marguc Janina , Van Kleef Gerben A. , Förster Jens
Published: September 2014

Life often presents us with obstacles to goals and the work arena is no exception. Two studies examined whether dealing with such obstacles promotes creative thought in goal pursuit. In Study 1, thinking about how to reach a goal with (versus without) an obstacle led participants to broaden especially goal‐relevant categories, which suggests that people first and foremost open up to more unusual means when tackling an obstacle. Moving beyond a passive broadening of categories, thinking about how to reach a goal with (versus without) an obstacle in Study 2 also led participants to actively generate more original means. Together these findings suggest that people's basic cognitive responses to obstacles are in the service of goals. Theoretical and organizational implications as well as the role of motivation and emotions are discussed.
Development of Equity Preferences in Boys and Girls Across Adolescence
Authors: Meuwese Rosa , Crone Eveline A. , de Rooij Mark , Güroğlu Berna
Published: September 2014

The aim of the current study was to examine the development of equity preferences across adolescence, for boys and girls separately. Participants from 8 to 18 years old (M = 14.09 years; N = 1,216) played four economic allocation games. Analyses revealed a decrease in equity preferences with age and this decrease was stronger for boys than for girls. There was also an age‐related increase in the preference for efficient outcomes (i.e., maximization of total available resources), which was again stronger for boys than for girls. Overall, although equity remains as a strong social norm, adolescents are decreasingly strict in adhering to the equity norm and show increasing flexibility in equity preferences.
Developmental Relations Between Vocabulary Knowledge and Reading Comprehension: A Latent Change Score Modeling Study
Authors: Quinn Jamie M. , Wagner Richard K. , Petscher Yaacov , Lopez Danielle
Published: September 2014

The present study followed a sample of first‐grade (N = 316, Mage = 7.05 at first test) through fourth‐grade students to evaluate dynamic developmental relations between vocabulary knowledge and reading comprehension. Using latent change score modeling, competing models were fit to the repeated measurements of vocabulary knowledge and reading comprehension to test for the presence of leading and lagging influences. Univariate models indicated growth in vocabulary knowledge, and reading comprehension was determined by two parts: constant yearly change and change proportional to the previous level of the variable. Bivariate models indicated previous levels of vocabulary knowledge acted as leading indicators of reading comprehension growth, but the reverse relation was not found. Implications for theories of developmental relations between vocabulary and reading comprehension are discussed.
Selecting cost‐effective areas for restoration of ecosystem services
Authors: Adame M. F. , Hermoso V. , Perhans K. , Lovelock C. E. , Herrera‐Silveira J. A.
Published: September 2014

Selection of areas for restoration should be based on cost‐effectiveness analysis to attain the maximum benefit with a limited budget and overcome the traditional ad hoc allocation of funds for restoration projects. Restoration projects need to be planned on the basis of ecological knowledge and economic and social constraints. We devised a novel approach for selecting cost‐effective areas for restoration on the basis of biodiversity and potential provision of 3 ecosystem services: carbon storage, water depuration, and coastal protection. We used Marxan, a spatial prioritization tool, to balance the provision of ecosystem services against the cost of restoration. We tested this approach in a mangrove ecosystem in the Caribbean. Our approach efficiently selected restoration areas that at low cost were compatible with biodiversity targets and that maximized the provision of one or more ecosystem services. Choosing areas for restoration of mangroves on the basis carbon storage potential, largely guaranteed the restoration of biodiversity and other ecosystem services.

Selección de Áreas Rentables para la Restauración de Servicios Ambientales
The Silent Board: How Language Diversity May Influence the Work Processes of Corporate Boards
Authors: Piekkari Rebecca , Oxelheim Lars , Randøy Trond
Published: September 2014

Manuscript Type

Empirical.

Research Question/Issue

Corporate boards often change their working language when they acquire foreign members. Consequently, boards “talk” in one language but “think” in another. The present study explores and explains how language diversity influences work processes of corporate boards.

Research Findings/Insights

On the basis of a multiple case study of nine multinational corporations (MNCs) from fourNordic countries, we discovered evidence of impoverished and silenced discussions in board meetings in those case companies that were unprepared to switch toEnglish as the new working language of the board. Some board members found it difficult to contribute to board meetings and articulate disagreement. In contrast, such effects were not revealed in the well‐prepared companies. Overall, the presence of employee representatives on the boards made it more difficult to conduct work processes inEnglish because these members often lacked sufficient language proficiency. Thus, our findings suggest that the board co‐determination act of theNordic corporate governance model may be associated with the hidden costs of using a non‐native language.

Theoretical/Academic Implications

Our study makes four contributions to research on board diversity. Firstly, it highlights the “silencing effect” of language diversity on board processes. Secondly, it emphasizes the linkage between language diversity and board processes. Thirdly, it provides additional evidence that language is a distinct dimension of diversity. Fourthly, it discovers language in board work as a new research topic that is worthy of scholarly attention.

Practitioner/Policy Implications

Firms need to anticipate the potential effects of language diversity on the work processes of their boards in order to ensure that “the voice of diversity” is heard. The board itself as well as the rest of the organization can take preparatory measures such as producing all board material in the new working language and selecting board members with the required language proficiency. Although these measures can be implemented gradually or at a faster pace, they need to be in place before foreign members join the board. Consistent use of one and the same language in the corporate board and the executive management team supports transparency and good corporate governance practices. In our opinion, reaping the benefits of board diversity is the particular responsibility of the chairperson. Even thoughEnglish is generally well understood in the Nordic countries, chairpersons should also consider the possible negative effects associated with the use of a board language that is non‐native to most of its members.
The Influence of Family Ownership on Corporate Social Responsibility: An International Analysis of Publicly Listed Companies
Authors: Rees William , Rodionova Tatiana
Published: September 2014

Manuscript Type

Empirical

Research Question/Issue

We investigate the impact of family equity holdings on three indicators of corporate social responsibility: environmental, social, and governance (ESG) rankings. We further evaluate how firm governance mediates the effect of family ownership on environmental and social improvements and how national governance systems influence the response of family holdings to ESG.

Research Findings/Insights

Based on a sample of 23,902 firm‐year observations drawn from 2002 to 2012 covering 46 countries and 3,893 firms, our findings show that both closely held equity and family ownership are negatively associated with ESG performance. When we control for governance, closely held equity is no longer associated with environmental and social rankings, but family ownership retains a significant negative association. These results are strong and consistent across liberal market economies (LME), whereas coordinated market economies (CME) exhibit generally weaker results and considerable diversity. Japan stands out as different from the other countries examined in depth.

Theoretical/Academic Implications

Our results are consistent with agency relationships driving decisions concerning ESG commitment in LMEs. They also emphasize the role of institutional differences given the weak and variable association between ownership and ESG in CMEs. We show that families may be able to influence decisions, possibly through participation in management, despite normally effective governance constraints. As the impact of ownership and governance varies across economies and ownership type, this implies that both agency and governance should be evaluated in the context of the economic environment.

Practitioner/Policy Implications

Our results offer insights to regulators and policy makers who intend to improve ESG performance. The results suggest that encouraging diversified ownership is particularly important in LMEs, that improvements in governance may benefit social and environmental performance where equity is closely held by institutions, but that governance may be less effective in the presence of family ownership.
Recipient body mass index and age interact to impact survival after heart transplantation
Authors: Weber Daniel J. , Hashmi Zubair A. , Gracon Adam S. A. , Hellman Yaron M. , Patel Ankur J. , Wozniak Thomas C. , Wang I‐wen
Published: September 2014

Although recipient body mass index (BMI) and age are known risk factors for mortality after heart transplantation, how they interact to influence survival is unknown. Our study utilized the UNOS registry from 1997 to 2012 to define the interaction between BMI and age and its impact on survival after heart transplantation. Recipients were stratified by BMI: underweight (<18.5), normal weight (18.5–24.99), overweight (25–29.99), and either moderate (30–34.99), severe (35–39.99), or very severe (≥40) obesity. Recipients were secondarily stratified based on age: 18–40 (younger recipients), 40–65 (reference group), and ≥65 (advanced age recipients). Among younger recipients, being underweight was associated with improved adjusted survival (HR 0.902; p = 0.010) while higher mortality was seen in younger overweight recipients (HR 1.260; p = 0.005). However, no differences in adjusted survival were appreciated in underweight and overweight advanced age recipients. Obesity (BMI ≥ 30) was associated with increased adjusted mortality in normal age recipients (HR 1.152; p = 0.021) and even more so with young (HR 1.576; p < 0.001) and advanced age recipients (HR 1.292; p = 0.001). These results demonstrate that BMI and age interact to impact survival as age modifies BMI–mortality curves, particularly with younger and advanced age recipients.
Olig2 overexpression accelerates the differentiation of mouse embryonic stem cells into oligodendrocyte progenitor cells in vitro
Authors: Yao Ruiqin , Wang Bei , Ren Chuanlu , Qu Xuebin , Luo Mengjiao , Zhang Qiang , Wang Huiping , Dong Fuxing , Wu Xiuxiang , Yang Lihua , Yu Hongli
Published: September 2014

Oligodendrocyte progenitor cells (OPCs) transplantation is receiving considerable attention in the field of regenerative medicine therapy for demyelinating diseases. Although embryonic stem cells (ESCs) have been successfully induced to differentiate into OPCs with cytokines cocktails in vitro, the regulatory roles of many key transcription factors in this process are not clear. Here, we introduced oligodendrocyte lineage transcription factor 2 (Olig2), a basic helix‐loop‐helix transcription factor, into mouse embryonic stem cells (mESCs) to investigate its effects on the differentiation of mESCs into OPCs. The results showed that Olig2 overexpression alone did not affect pluripotency of mESCs, but in the stimulation of differentiating cocktails, Olig2 accelerated mESCs to differentiate into OPCs, shortening the induction time span from normal 21 days to 11 days. Further study demonstrated the Olig2‐mESCs derived OPCs were able to differentiate into C‐type natriuretic peptid (CNP) and Myelin Basic Protein (MBP) positive mature oligodendrocytes (OLs) in vitro, suggesting these induced OPCs might be favorable for myelin regeneration in vivo.
Neurogenesis and neuronal circuit formation in the Drosophila visual center
Authors: Suzuki Takumi , Sato Makoto
Published: September 2014

The Drosophila optic lobe is composed of a wide variety of neurons that form laminar structures and columnar units. The fly optic lobe shares structural features with the mammalian brain, and fly genetics allow precise genetic manipulations. Thus, the Drosophila visual center is an excellent model for studying the mechanisms underlying the establishment of a functional neuronal circuit during brain development. However, little is understood about the developmental mechanisms that produce neuronal diversity and establish neuronal circuits in the medulla, the largest component of the optic lobe. Our recent research revealed key features of medulla development, such as birth‐order‐dependent specification of neuronal types and the subdivision of the medulla primordium into concentric zones, which is characterized by the expression of four transcription factors. Here, we review recent investigations into the development of the medulla and discuss the mechanisms that establish functional neuronal circuits.
Control of brain development and homeostasis by local and systemic insulin signalling
Authors: Liu J. , Spéder P. , Brand A. H.
Published: September 2014

Insulin and insulin‐like growth factors (IGFs) are important regulators of growth and metabolism. In both vertebrates and invertebrates, insulin/IGFs are made available to various organs, including the brain, through two routes: the circulating systemic insulin/IGFs act on distant organs via endocrine signalling, whereas insulin/IGF ligands released by local tissues act in a paracrine or autocrine fashion. Although the mechanisms governing the secretion and action of systemic insulin/IGF have been the focus of extensive investigation, the significance of locally derived insulin/IGF has only more recently come to the fore. Local insulin/IGF signalling is particularly important for the development and homeostasis of the central nervous system, which is insulated from the systemic environment by the blood–brain barrier. Local insulin/IGF signalling from glial cells, the blood–brain barrier and the cerebrospinal fluid has emerged as a potent regulator of neurogenesis. This review will address the main sources of local insulin/IGF and how they affect neurogenesis during development. In addition, we describe how local insulin/IGF signalling couples neural stem cell proliferation with systemic energy state in Drosophila and in mammals.
Metabolic effects of portal vein sensing
Authors: Mithieux G.
Published: September 2014

The extrinsic gastrointestinal nerves are crucial in the sensing of nutrients and hormones and its translation in terms of control of food intake. Major macronutrients like glucose and protein are sensed by the extrinsic nerves located in the portal vein walls, which signal to the brain and account for the satiety phenomenon they promote. Glucose is sensed in the portal vein by neurons expressing the glucose receptor SGLT3, which activate the main regions of the brain involved in the control of food intake. Proteins indirectly act on food intake by inducing intestinal gluconeogenesis and its sensing by the portal glucose sensor. The mechanism involves a prior antagonism by peptides of the μ‐opioid receptors present in the portal vein nervous system and a reflex arc with the brain inducing intestinal gluconeogenesis. In a comparable manner, short‐chain fatty acids produced from soluble fibre act via intestinal gluconeogenesis to exert anti‐obesity and anti‐diabetic effects. In the case of propionate, the mechanism involves a prior activation of the free fatty acid receptor FFAR3 present in the portal nerves and a reflex arc initiating intestinal gluconeogenesis.
The search for the mechanism of early sympathetic islet neuropathy in autoimmune diabetes
Authors: Taborsky G. J. , Mei Q. , Hackney D. J. , Mundinger T. O.
Published: September 2014

This review outlines our search for the mechanism causing the early loss of islet sympathetic nerves in autoimmune diabetes. Since our previous work has documented the importance of autonomic stimulation of glucagon secretion during hypoglycaemia, the loss of these nerves may contribute to the known impairment of this specific glucagon response early in human type 1 diabetes. We therefore briefly review the contribution that autonomic activation, and sympathetic neural activation in particular, makes to the subsequent glucagon response to hypoglycaemia. We also detail evidence that animal models of autoimmune diabetes mimic both the early loss of islet sympathetic nerves and the impaired glucagon response seen in human type 1 diabetes. Using data from these animal models, we examine mechanisms by which this loss of islet nerves could occur. We provide evidence that it is not due to diabetic hyperglycaemia, but is related to the lymphocytic infiltration of the islet. Ablating the p75 neurotrophin receptor, which is present on sympathetic axons, prevents early sympathetic islet neuropathy (eSIN), but, interestingly, not diabetes. Thus, we appear to have separated the immune‐related loss of islet sympathetic nerves from the immune‐mediated destruction of islet β‐cells. Finally, we speculate on a way to restore the sympathetic innervation of the islet.
Ghrelin signalling in β‐cells regulates insulin secretion and blood glucose
Authors: Yada T. , Damdindorj B. , Rita R. S. , Kurashina T. , Ando A. , Taguchi M. , Koizumi M. , Sone H. , Nakata M. , Kakei M. , Dezaki K.
Published: September 2014

Insulin secretion from pancreatic islet β‐cells is stimulated by glucose. Glucose‐induced insulin release is potentiated or suppressed by hormones and neural substances. Ghrelin, an acylated 28‐amino acid peptide, was isolated from the stomach in 1999 as the endogenous ligand for the growth hormone (GH) secretagogue‐receptor (GHS‐R). Circulating ghrelin is produced predominantly in the stomach and to a lesser extent in the intestine, pancreas and brain. Ghrelin, initially identified as a potent stimulator of GH release and feeding, has been shown to suppress glucose‐induced insulin release. This insulinostatic action is mediated by Gαi2 subtype of GTP‐binding proteins and delayed outward K+ (Kv) channels. Interestingly, ghrelin is produced in pancreatic islets. The ghrelin originating from islets restricts insulin release and thereby upwardly regulates the systemic glucose level. Furthermore, blockade or elimination of ghrelin enhances insulin release, which can ameliorate glucose intolerance in high‐fat diet fed mice and ob/ob mice. This review focuses on the insulinostatic action of ghrelin, its signal transduction mechanisms in islet β‐cells, ghrelin's status as an islet hormone, physiological roles of ghrelin in regulating systemic insulin levels and glycaemia, and therapeutic potential of the ghrelin‐GHS‐R system as the target to treat type 2 diabetes.
Neurotransmitter control of islet hormone pulsatility
Authors: Gylfe E. , Tengholm A.
Published: September 2014

Pulsatile secretion is an inherent property of hormone‐releasing pancreatic islet cells. This secretory pattern is physiologically important and compromised in diabetes. Neurotransmitters released from islet cells may shape the pulses in auto/paracrine feedback loops. Within islets, glucose‐stimulated β‐cells couple via gap junctions to generate synchronized insulin pulses. In contrast, α‐ and δ‐cells lack gap junctions, and glucagon release from islets stimulated by lack of glucose is non‐pulsatile. Increasing glucose concentrations gradually inhibit glucagon secretion by α‐cell‐intrinsic mechanism/s. Further glucose elevation will stimulate pulsatile insulin release and co‐secretion of neurotransmitters. Excitatory ATP may synchronize β‐cells with δ‐cells to generate coinciding pulses of insulin and somatostatin. Inhibitory neurotransmitters from β‐ and δ‐cells can then generate antiphase pulses of glucagon release. Neurotransmitters released from intrapancreatic ganglia are required to synchronize β‐cells between islets to coordinate insulin pulsatility from the entire pancreas, whereas paracrine intra‐islet effects still suffice to explain coordinated pulsatile release of glucagon and somatostatin. The present review discusses how neurotransmitters contribute to the pulsatility at different levels of integration.
Fat‐free mass loss generated with weight loss in overweight and obese adults: what may we expect?
Authors: Dixon J. B. , Lambert E. A. , Grima M. , Rice T. , Lambert G. W. , Straznicky N. E.
Published: September 2014

There is concern that intentional weight loss may generate excessive loss of fat‐free mass (FFM). Idealists target minimal loss of FFM, while others consider that FFM loss of up to 25% of weight loss is acceptable. In a cross‐sectional study of 275 weight‐stable, overweight or obese adults, we used whole‐body dual‐energy X‐ray absorptiometry to measure FFM. A range of models was used to estimate the expected ΔFFM/Δweight ratio required to attain the body composition of a weight‐stable individual at a lower body mass index (BMI). Higher BMI was associated linearly with higher FFM in men and women. Proportional ΔFFM/Δweight was influenced by sex, BMI and age. Direct scatter plot analysis, quadratic curve fit modelling and linear FFM–BMI modelling provided similar estimates for each model of ΔFFM/Δweight ratio, with 40% for men and 33% for women. These results show that the 25% rule is inappropriate and our estimates are higher than those generally reported after intentional weight loss indicating favourable preservation of FFM.
Environmental and economic impact assessment of alien and invasive fish species in Europe using the generic impact scoring system
Authors: van der Veer Gabriel , Nentwig Wolfgang
Published: September 2014

Invasions by alien species are one of the major threats to the native environment. There are multifold attempts to counter alien species, but limited resources for mitigation or eradication programmes makes prioritisation indispensable. We used the generic impact scoring system to assess the impact of alien fish species in Europe. It prioritises species, but also offers the possibility to compare the impact of alien invasive species between different taxonomic groups. For alien fish in Europe, we compiled a list of 40 established species. By literature research, we assessed the environmental impact (through herbivory, predation, competition, disease transmission, hybridisation and ecosystem alteration) and economic impact (on agriculture, animal production, forestry, human infrastructure, human health and human social life) of each species. The goldfish/gibel complex Carassius auratus/C. gibelio scored the highest impact points, followed by the grass carp Ctenopharyngodon idella and the topmouth gudgeon Pseudorasbora parva. According to our analyses, alien fish species have the strongest impact on the environment through predation, followed by competition with native species. Besides negatively affecting animal production (mainly in aquaculture), alien fish have no pronounced economic impact. At the species level, C. auratus/C. gibelio show similar impact scores to the worst alien mammals in Europe. This study indicates that the generic impact scoring system is useful to investigate the impact of alien fish, also allowing cross‐taxa comparisons. Our results are therefore of major relevance for stakeholders and decision‐makers involved in management and eradication of alien fish species.
Impact of online resources and social media on help‐seeking behaviour in youth with psychotic symptoms
Authors: Birnbaum Michael L. , Candan Kristin , Libby Ilana , Pascucci Olivia , Kane John
Published: September 2014

Aim

The objective of the study was to explore the content of existing online resources available to information‐seeking youth as psychotic symptoms first emerge and determine how these resources may influence initiation of care.

Methods

Using 18 hypothetical search terms, developed by the Early Treatment Programme (ETP) staff, we searched three of the most popular websites used by the youth (Google, Facebook and Twitter) and extracted the first five hits from each. Sites were categorized into those that encouraged help seeking, those that potentially contribute to treatment delay, those with an undetermined impact and those that were unrelated to treatment.

Results

An alarmingly few of the first five hits from the top three online resources encourage potentially psychotic youth to seek professional evaluation. The majority of our search results yielded unmonitored chat forums that lacked a unified message. The remainder promoted stigma, normalized potentially psychotic experiences or were completely unrelated to mental health.

Conclusion

We must develop innovative, easy‐to‐access and youth‐focused online and social media experiences that encourage symptomatic youth to seek care.
Schizotypy and impaired basic face recognition? Another non‐confirmatory study
Authors: Bell Vaughan , Halligan Peter
Published: September 2014

Aim

Although schizotypy has been found to be reliably associated with a reduced recognition of facial affect, the few studies that have tested the association between basic face recognition abilities and schizotypy have found mixed results. This study formally tested the association in a large non‐clinical sample with established neurological measures of face recognition.

Methods

Two hundred and twenty‐seven participants completed the Oxford–Liverpool Inventory of Feelings and Experiences schizotypy scale and completed the Famous Faces Test and the Cardiff Repeated Recognition Test for Faces.

Results

No association between any schizotypal dimension and performance on either of the facial recognition and learning tests was found. The null results can be accepted with a high degree of confidence.

Conclusions

Further additional evidence is provided for a lack of association between schizotypy and basic face recognition deficits.
The effects of phenotypic plasticity and local adaptation on forecasts of species range shifts under climate change
Authors: Valladares Fernando , Matesanz Silvia , Guilhaumon François , Araújo Miguel B. , Balaguer Luis , Benito‐Garzón Marta , Cornwell Will , Gianoli Ernesto , van Kleunen Mark , Naya Daniel E. , Nicotra Adrienne B. , Poorter Hendrik , Zavala Miguel A.
Published: September 2014

Species are the unit of analysis in many global change and conservation biology studies; however, species are not uniform entities but are composed of different, sometimes locally adapted, populations differing in plasticity. We examined how intraspecific variation in thermal niches and phenotypic plasticity will affect species distributions in a warming climate. We first developed a conceptual model linking plasticity and niche breadth, providing five alternative intraspecific scenarios that are consistent with existing literature. Secondly, we used ecological niche‐modeling techniques to quantify the impact of each intraspecific scenario on the distribution of a virtual species across a geographically realistic setting. Finally, we performed an analogous modeling exercise using real data on the climatic niches of different tree provenances. We show that when population differentiation is accounted for and dispersal is restricted, forecasts of species range shifts under climate change are even more pessimistic than those using the conventional assumption of homogeneously high plasticity across a species' range. Suitable population‐level data are not available for most species so identifying general patterns of population differentiation could fill this gap. However, the literature review revealed contrasting patterns among species, urging greater levels of integration among empirical, modeling and theoretical research on intraspecific phenotypic variation.
Predicting probability of occurrence and factors affecting distribution and abundance of three Ozark endemic crayfish species at multiple spatial scales
Authors: Nolen Matthew S. , Magoulick Daniel D. , DiStefano Robert J. , Imhoff Emily M. , Wagner Brian K.
Published: September 2014

Crayfishes and other freshwater aquatic fauna are particularly at risk globally due to anthropogenic demand, manipulation and exploitation of freshwater resources and yet are often understudied. The Ozark faunal region of Missouri and Arkansas harbours a high level of aquatic biological diversity, especially in regard to endemic crayfishes. Three such endemics, Orconectes eupunctus, Orconectes marchandi and Cambarus hubbsi, are threatened by limited natural distribution and the invasions of Orconectes neglectus.

We examined how natural and anthropogenic abiotic factors influence these three species across multiple spatial scales. Local and landscape environmental variables were used as predictors in classification and regression tree models at stream segment and segmentshed scales to determine their relation to presence/absence and density of the three species.

Orconectes eupunctus presence was positively associated with stream size, current velocity and spring flow volume. Orconectes marchandi presence was predicted primarily by dolomite geology and water chemistry variables. Cambarus hubbsi was associated with larger stream size, with highest densities occurring in deep waters. Stream segment and segmentshed scale models were similar, but there were important differences based on species and response variables (presence/absence versus density). Stream segment scale models consistently performed better than or equal to segmentshed scale models.

Anthropogenic abiotic environmental variables were of minor importance in most models, with the exception of O. marchandi being negatively related to road density and human population density. Classification tree models predicting distribution performed well when compared to random assignment, but regression trees were generally poor in explaining variation in density.

We found that a range of environmental variables were important in predicting crayfish distribution and abundance at multiple spatial scales and their importance was species‐, response variable‐ and scale dependent. We would encourage others to examine the influence of spatial scale on species distribution and abundance patterns.
Deletion of the four phospholipid hydroperoxide glutathione peroxidase genes accelerates aging in Caenorhabditis elegans
Authors: Sakamoto Taro , Maebayashi Kana , Nakagawa Yasuhito , Imai Hirotaka
Published: September 2014

The glutathione peroxidase (GPx) family is a major antioxidant enzyme family that catalyzes the reduction of a variety of hydroperoxides. GPxs are divided into selenium‐ and nonselenium‐containing GPxs. Because of their efficient antioxidant activity, which depends on the presence of the amino acid residue selenocysteine, selenium‐containing GPxs have been the subject of many studies. However, the physiological roles of the nonselenium GPxs remain unclear. Here, we report that the deletion of phospholipid hydroperoxide glutathione peroxidase (PHGPx) homologues causes accelerated aging that leads to a shortened lifespan in Caenorhabditis elegans. PHGPx is an antioxidant enzyme that directly reduces the phospholipid hydroperoxides generated in biomembranes. The quadruple phgpx mutant gpx‐1; gpx‐2; gpx‐6; gpx‐7 developed normally, reached adulthood and reproduced as well as the wild type. However, a lifespan analysis showed that the quadruple phgpx mutant had a short maximum lifespan, with an age‐related increase in its mortality rate. The intestine is the primary tissue expressing gpx‐1, gpx‐2, gpx‐6 and gpx‐7 in C. elegans, and the expression of gpx‐6 is greatly enhanced under starvation conditions. These results suggest that the C. elegans PHGPx homologues have important functions in the regulation of aging, probably by reducing oxidative damage in the intestine.
Thiamine in the treatment of Wernicke encephalopathy in patients with alcohol use disorders
Authors: Latt N. , Dore G.
Published: September 2014

Wernicke encephalopathy is an acute, reversible neuropsychiatric emergency due to thiamine deficiency. Urgent and adequate thiamine replacement is necessary to avoid death or progression to Korsakoff syndrome with largely irreversible brain damage. Wernicke Korsakoff syndrome refers to a condition where features of Wernicke encephalopathy are mixed with those of Korsakoff syndrome. Although thiamine is the cornerstone of treatment of Wernicke encephalopathy, there are no universally accepted guidelines with regard to its optimal dose, mode of administration, frequency of administration or duration of treatment. Currently, different dose recommendations are being made. We present recommendations for the assessment and treatment of Wernicke encephalopathy based on literature review and our clinical experience.
The Sahul–Sunda floristic exchange: dated molecular phylogenies document Cenozoic intercontinental dispersal dynamics
Authors: Crayn Darren M. , Costion Craig , Harrington Mark G.
Published: September 2014

Aim

The aim was to characterize the temporal dynamics of the Sahul–Sunda floristic exchange using published dated molecular phylogenies.

Location

The Sahul and Sunda shelves in Australasia and Southeast Asia.

Methods

Dated molecular phylogenies were compiled from the literature for plant clades that contained at least one node representing a biogeographical disjunction between the Sahul and Sunda shelves. For these nodes the age, ancestral geographical area and propagule type were determined.

Results

We analysed 49 clades from 21 published phylogenies representing a diverse set of angiosperm lineages. The inferred age of the disjunctions ranged fromc. 33 Ma toc. 1 Ma; the earliest age marked the onset of the Sahul–Sunda floristic exchange. Disjunctions (resulting from dispersal/migration events) occurred at the rate of 0.41 per 2 Myr between 34 and 12 Ma. Thereafter the rate sharply increased, coincident with the shelves effectively merging. For nearly two‐thirds (63%) of the nodes Sunda was the ancestral area, and for 90% the ancestral species possessed zoochorous propagules.

Main conclusions

There is strong support for a dynamic model of floristic exchange between Sahul and Sunda. Fewer (18%) disjunctions occurred prior to Sahul and Sunda merging around 12 Ma, which we attribute to a combination of the effect of overwater dispersal barriers and relatively stable, saturated species assemblages resistant to the establishment of newly arrived lineages. The exchange, once underway, was strongly asymmetrical; eastwards migration into Sahul predominated over the reverse by a factor ofc. 2.4. As zoochorous lineages were overrepresented among the successful dispersers, we infer a strong role for localized animal dispersal across narrow water barriers.
The roles of disturbance, topography and climate in determining the leading and rear edges of population range limits
Authors: Slaton Michèle R.
Published: September 2014

Aim

To identify the ecosystem features most important for differentiating leading edges from rear edges of plant population distributions, and for distinguishing both from contiguous‐range sites.

Location

Eastern California, USA.

Methods

Habitats supporting multiple plant populations at their range edges were analysed, including 32 rear‐edge, 32 leading‐edge and 526 control sites within contiguous ranges. Multivariate modelling techniques, including general linear and additive modelling, ordination and classification trees were used to identify the biotic and abiotic factors that control range edges.

Results

Rear edges were associated with lower solar radiation and potential evapotranspiration, as would generally be expected as ranges shift in a warming climate regime. Leading edges were associated with lower topographical positions, such as canyon bottoms, and were characterized by recent disturbance and early successional stages. Rear edges occurred mainly in undisturbed sites.

Main conclusions

The interacting roles of biological and physical factors in determining population range limits have recently gained attention as the need to predict ecosystem shifts in a changing climate increases. Further understanding and recognition of disturbance in facilitating the expansion of native species' ranges and in conserving relict populations will enhance the ability of land managers to maintain biodiversity and ecosystem resilience as climate continues to change.