bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimentally increased noise levels change spatial and singing behaviour
Authors: McLaughlin Kirsty Elizabeth , Kunc Hansjoerg P.
Published: November 2012

The reasons why animal populations decline in response to anthropogenic noise are still poorly understood. To understand how populations are affected by noise, we must understand how individuals are affected by noise. By modifying the acoustic environment experimentally, we studied the potential relationship between noise levels and both spatial and singing behaviour in the European robin (
Erithacus rubecula
). We found that with increasing noise levels, males were more likely to move away from the noise source and changed their singing behaviour. Our results provide the first experimental evidence in a free ranging species, that not merely the presence of noise causes changes in behaviour and distribution, but that the level of noise pollution plays a crucial role as well. Our results have important implications for estimating the impact of infrastructure which differs in the level of noise produced. Thus, governmental planning bodies should not only consider the physical effect on the landscape when assessing the impact of new infrastructure, but also the noise levels emitted, which may reduce the loss of suitable habitats available for animals.
Marine trophic diversity in an anadromous fish is linked to its life-history variation in fresh water
Authors: Johnson Susan P. , Schindler Daniel E.
Published: November 2012

We used carbon and nitrogen stable isotopes from muscle tissues accrued in the ocean to examine whether marine foraging tactics in anadromous sockeye salmon (
Oncorhynchus nerka
) are linked to their ultimate freshwater life history as adults. Adults from large-bodied populations spawning in deep freshwater habitats had more enriched
δ
15
N than individuals from small-bodied populations from shallow streams. Within populations, earlier maturing individuals had higher
δ
15
N than older fish. These differences in
δ
15
N suggest that the fish with different life histories or spawning habitats in freshwater either fed at different trophic positions or in different habitats in the ocean. We propose that, nested within interspecific diversity in the ecological attributes of salmon, population and life-history diversity in spawning adults is associated with variation in marine foraging tactics. These results further indicate that the trophic diversity of sockeye salmon in the ocean may be linked to trade-offs in ecological and evolutionary constraints they eventually experience as adults in freshwater ecosystems.
Wormholes record species history in space and time
Authors: Hedges S. Blair
Published: November 2012

Genetic and fossil data often lack the spatial and temporal precision for tracing the recent biogeographic history of species. Data with finer resolution are needed for studying distributional changes during modern human history. Here, I show that printed wormholes in rare books and artwork are trace fossils of wood-boring species with unusually accurate locations and dates. Analyses of wormholes printed in western Europe since the fifteenth century document the detailed biogeographic history of two putative species of invasive wood-boring beetles. Their distributions now overlap broadly, as an outcome of twentieth century globalization. However, the wormhole record revealed, unexpectedly, that their original ranges were contiguous and formed a stable line across central Europe, apparently a result of competition. Extension of the wormhole record, globally, will probably reveal other species and evolutionary insights. These data also provide evidence for historians in determining the place of origin or movement of a woodblock, book, document or art print.
Applications of polymeric adjuvants in studying autoimmune responses and vaccination against infectious diseases
Authors: Shakya Akhilesh Kumar , Nandakumar Kutty Selva
Published: November 2012

Polymers as an adjuvant are capable of enhancing the vaccine potential against various infectious diseases and also are being used to study the actual autoimmune responses using self-antigen(s) without involving any major immune deviation. Several natural polysaccharides and their derivatives originating from microbes and plants have been tested for their adjuvant potential. Similarly, numerous synthetic polymers including polyelectrolytes, polyesters, polyanhydrides, non-ionic block copolymers and external stimuli responsive polymers have demonstrated adjuvant capacity using different antigens. Adjuvant potential of these polymers mainly depends on their solubility, molecular weight, degree of branching and the conformation of polymeric backbone. These polymers have the ability not only to activate humoral but also cellular immune responses in the host. The depot effect, which involves slow release of antigen over a long duration of time, using different forms (particulate, solution and gel) of polymers, and enhances the co-stimulatory signals for optimal immune activation, is the underlying principle of their adjuvant properties. Possibly, polymers may also interact and activate various toll-like receptors and inflammasomes, thus involving several innate immune system players in the ensuing immune response. Biocompatibility, biodegradability, easy production and purification, and non-toxic properties of most of the polymers make them attractive candidates for substituting conventional adjuvants that have undesirable effects in the host.
Towards a simplification of models using regression trees
Authors: Eynaud Y. , Nerini D. , Baklouti M. , Poggiale J.-C.
Published: November 2012

Over-parametrization in modelling is a well-known issue that makes it hard to identify which part of a model is responsible for a given behaviour. In line with that ascertainment, this work presents the outline of an empirical method to simplify models by decreasing the number of parameters. By using regression trees to classify outputs according to related input parameters, the method provides the modeller with an objective tool to reduce the range of the used parameters and, under certain conditions, to establish relations between them. Thereby, the complexity of the model is reduced on the basis of mathematical arguments. As an example, a dynamic energy budget-based model of a mesopelagic bacterial ecosystem is simplified using the presented method. The main benefits of such a method are thus highlighted: (i) more robust parameter estimations; (ii) less complex formulations; and (iii) fewer modelling assumptions. To conclude, the difficulties encountered are discussed, and several solutions are proposed to deal with them.
Seed dispersal networks in the Galápagos and the consequences of alien plant invasions
Authors: Heleno Ruben H. , Olesen Jens M. , Nogales Manuel , Vargas Pablo , Traveset Anna
Published: November 2012

Alien plants are a growing threat to the Galápagos unique biota. We evaluated the impact of alien plants on eight seed dispersal networks from two islands of the archipelago. Nearly 10 000 intact seeds from 58 species were recovered from the droppings of 18 bird and reptile dispersers. The most dispersed invaders were
Lantana camara
,
Rubus niveus
and
Psidium guajava
, the latter two likely benefiting from an asynchronous fruit production with most native plants, which facilitate their consumption and spread. Lava lizards dispersed the seeds of 27 species, being the most important dispersers, followed by small ground finch, two mockingbirds, the giant tortoise and two insectivorous birds. Most animals dispersed alien seeds, but these formed a relatively small proportion of the interactions. Nevertheless, the integration of aliens was higher in the island that has been invaded for longest, suggesting a time-lag between alien plant introductions and their impacts on seed dispersal networks. Alien plants become more specialized with advancing invasion, favouring more simplified plant and disperser communities. However, only habitat type significantly affected the overall network structure. Alien plants were dispersed via two pathways: dry-fruited plants were preferentially dispersed by finches, while fleshy fruited species were mostly dispersed by other birds and reptiles.
Are elder siblings helpers or competitors? Antagonistic fitness effects of sibling interactions in humans
Authors: Nitsch Aïda , Faurie Charlotte , Lummaa Virpi
Published: November 2012

Determining the fitness consequences of sibling interactions is pivotal for understanding the evolution of family living, but studies investigating them across lifetime are lacking. We used a large demographic dataset on preindustrial humans from Finland to study the effect of elder siblings on key life-history traits. The presence of elder siblings improved the chances of younger siblings surviving to sexual maturity, suggesting that despite a competition for parental resources, they may help rearing their younger siblings. After reaching sexual maturity however, same-sex elder siblings' presence was associated with reduced reproductive success in the focal individual, indicating the existence of competition among same-sex siblings. Overall, lifetime fitness was reduced by same-sex elder siblings' presence and increased by opposite-sex elder siblings' presence. Our study shows opposite effects of sibling interactions depending on the life-history stage, and highlights the need for using long-term fitness measures to understand the selection pressures acting on sibling interactions.
Oxytocin-like receptors mediate pair bonding in a socially monogamous songbird
Authors: Klatt James D. , Goodson James L.
Published: November 2012

Although many species form socially monogamous pair bonds, relevant neural mechanisms have been described for only a single species, the prairie vole (
Microtus ochrogaster
). In this species, pair bonding is strongly dependent upon the nonapeptides oxytocin (OT) and vasopressin, in females and males, respectively. Because monogamy has evolved many times in multiple lineages, data from additional species are required to determine whether similar peptide mechanisms modulate bonding when monogamy evolves independently. Here we test the hypothesis that OT-like receptor activation is required for pair bond formation in the socially monogamous zebra finch (
Taeniopygia guttata
). Males and females were administered chronic intracerebroventricular infusions of saline or an OT receptor antagonist and were observed twice daily for 3 days in a colony environment. A variety of affiliative, aggressive and other behaviours were quantified. The antagonist produced significant and selective effects on pair bonding (latency to pair; number of sessions paired; stable pairing) and the associated behaviour of allopreening. Importantly, findings for males follow the trends of females; this yields main effects of treatment in two-way ANOVAs, although within-sex analyses are significant only for females. These data provide evidence for both convergent evolution and species diversity in the neuroendocrine mechanisms of pair bonding.
Gustatory habituation in Drosophila relies on rutabaga (adenylate cyclase)-dependent plasticity of GABAergic inhibitory neurons
Authors: Paranjpe Pushkar , Rodrigues Veronica , VijayRaghavan K. , Ramaswami Mani
Published: November 2012

In some situations, animals seem to ignore stimuli which in other contexts elicit a robust response. This attenuation in behavior, which enables animals to ignore a familiar, unreinforced stimulus, is called habituation. Despite the ubiquity of this phenomenon, it is generally poorly understood in terms of the underlying neural circuitry. Hungry fruit flies show a proboscis extension reflex (PER) when sensory receptors are stimulated by sugars. The PER is usually followed by feeding. However, if feeding is disallowed following sugar stimulation, PER is no longer robust, and the animal is considered to be habituated to this stimulus. Our results suggest that PER habituation requires an adenylate cyclase-dependent enhancement of inhibitory output of GABAergic neurons in the subesophageal ganglion (SOG), which mediates PER. GABA synthesis in and release from glutamic acid decarboxylase (GAD1) expressing neurons is necessary, and GABAA receptors on cholinergic neurons are required for PER habituation. The proposed inhibitory potentiation requires glutamate/NMDA-receptor signaling, possibly playing a role in stimulus selectivity. We explain why these data provide significant and independent support for a general model in which inhibitory potentiation underlies habituation in multiple neural systems and species.
Thermal Acclimation of the Symbiotic Alga Symbiodinium spp. Alleviates Photobleaching under Heat Stress
Authors: Takahashi Shunichi , Yoshioka-Nishimura Miho , Nanba Daisuke , Badger Murray R.
Published: November 2012

A moderate increase in seawater temperature causes coral bleaching, at least partially through photobleaching of the symbiotic algae Symbiodinium spp. Photobleaching of Symbiodinium spp. is primarily associated with the loss of light-harvesting proteins of photosystem II (PSII) and follows the inactivation of PSII under heat stress. Here, we examined the effect of increased growth temperature on the change in sensitivity of Symbiodinium spp. PSII inactivation and photobleaching under heat stress. When Symbiodinium spp. cells were grown at 25°C and 30°C, the thermal tolerance of PSII, measured by the thermal stability of the maximum quantum yield of PSII in darkness, was commonly enhanced in all six Symbiodinium spp. tested. In Symbiodinium sp. CCMP827, it took 6 h to acquire the maximum PSII thermal tolerance after transfer from 25°C to 30°C. The effect of increased growth temperature on the thermal tolerance of PSII was completely abolished by chloramphenicol, indicating that the acclimation mechanism of PSII is associated with the de novo synthesis of proteins. When CCMP827 cells were exposed to light at temperature ranging from 25°C to 35°C, the sensitivity of cells to both high temperature-induced photoinhibition and photobleaching was ameliorated by increased growth temperatures. These results demonstrate that thermal acclimation of Symbiodinium spp. helps to improve the thermal tolerance of PSII, resulting in reduced inactivation of PSII and algal photobleaching. These results suggest that whole-organism coral bleaching associated with algal photobleaching can be at least partially suppressed by the thermal acclimation of Symbiodinium spp. at higher growth temperatures.
Beam-induced oxidation of monomeric U(IV) species
Authors: Alessi Daniel S. , Uster Benjamin , Borca Camelia N. , Grolimund Daniel , Bernier-Latmani Rizlan
Published: November 2012

UraniumLIII-edge X-ray absorption spectroscopy is often used to probe the oxidation state and coordination of uranium in environmental samples, and micrometre-sized beams can be used to spatially map the distribution of uranium relative to other elements. Here a variety of uranium-containing environmental samples are analyzed at both microbeam and larger beam sizes to determine whether reoxidation of U(IV) occurred. Monomeric U(IV), a recently discovered product of U(VI) reduction by microbes and certain iron-bearing minerals at uranium-contaminated field sites, was found to be reoxidized during microbeam (3 µm × 2 µm) analysis of biomass and sediments containing the species but not at larger beam sizes. Thus, care must be taken when using X-ray microprobes to analyze samples containing monomeric U(IV).
A comparative study of X-ray tomographic microscopy on shales at different synchrotron facilities: ALS, APS and SLS
Authors: Kanitpanyacharoen Waruntorn , Parkinson Dilworth Y. , De Carlo Francesco , Marone Federica , Stampanoni Marco , Mokso Rajmund , MacDowell Alastair , Wenk Hans-Rudolf
Published: November 2012

Synchrotron radiation X-ray tomographic microscopy (SRXTM) was used to characterize the three-dimensional microstructure, geometry and distribution of different phases in two shale samples obtained from the North Sea (sample N1) and the Upper Barnett Formation in Texas (sample B1). Shale is a challenging material because of its multiphase composition, small grain size, low but significant amount of porosity, as well as strong shape- and lattice-preferred orientation. The goals of this round-robin project were to (i) characterize microstructures and porosity on the micrometer scale, (ii) compare results measured at three synchrotron facilities, and (iii) identify optimal experimental conditions of high-resolution SRXTM for fine-grained materials. SRXTM data of these shales were acquired under similar conditions at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory, USA, the Advanced Photon Source (APS) of Argonne National Laboratory, USA, and the Swiss Light Source (SLS) of the Paul Scherrer Institut, Switzerland. The data reconstruction of all datasets was handled under the same procedures in order to compare the data quality and determine phase proportions and microstructures. With a 10× objective lens the spatial resolution is approximately 2 µm. The sharpness of phase boundaries in the reconstructed data collected from the APS and SLS was comparable and slightly more refined than in the data obtained from the ALS. Important internal features, such as pyrite (high-absorbing), and low-density features, including pores, fractures and organic matter or kerogen (low-absorbing), were adequately segmented on the same basis. The average volume fractions of low-density features for sample N1 and B1 were estimated at 6.3 (6)% and 4.5 (4)%, while those of pyrite were calculated to be 5.6 (6)% and 2.0 (3)%, respectively. The discrepancy of data quality and volume fractions were mainly due to different types of optical instruments and varying technical set-ups at the ALS, APS and SLS.
Optimization of multilayer Laue lenses for a scanning X-ray microscope
Authors: Yan Hanfei , Chu Yong S.
Published: November 2012

Multilayer Laue lenses (MLLs) have demonstrated great capabilities for efficiently focusing hard X-rays down to the nanometer scale. Optimized use of MLLs in a scanning X-ray microscope requires careful consideration of a number of practical parameters other than resolution and efficiency in order to optimize the microscope's performance and scientific throughput. Here, relationships among the apodization effect owing to the presence of a beamstop, the monochromaticity requirement and the allowable working distance are discussed, as well as their impacts on the performance of the optics. Based on these discussions, optimal MLL schemes aiming at 10 nm resolution for a scanning X-ray microscope for the Hard X-ray Nanoprobe (HXN) beamline at National Synchrotron Light Source II are presented.
Life history and the ecology of stress: how do glucocorticoid hormones influence life‐history variation in animals?
Authors: Crespi Erica J. , Williams Tony D. , Jessop Tim S. , Delehanty Brendan
Published: November 2012

Glucocorticoids hormones (GCs) are intuitively important for mediation of age‐dependent vertebrate life‐history transitions through their effects on ontogeny alongside underpinning variation in life‐history traits and trade‐offs in vertebrates. These concepts largely derive from the ability of GCs to alter energy allocation, physiology and behaviour that influences key life‐history traits involving age‐specific life‐history transitions, reproduction and survival.

Studies across vertebrates have shown that the neuroendocrine stress axis plays a role in the developmental processes that lead up to age‐specific early life‐history transitions. While environmental sensitivity of the stress axis allows for it to modulate the timing of these transitions within species, little is known as to how variation in stress axis function has been adapted to produce interspecific variation in the timing of life‐history transitions.

Our assessment of the literature confirms that of previous reviews that there is only equivocal evidence for correlative or direct functional relationships between GCs and variation in reproduction and survival. We conclude that the relationships between GCs and life‐history traits are complex and general patterns cannot be easily discerned with current research approaches and experimental designs.

We identify several future research directions including: (i) integration of proximate and ultimate measures, including longitudinal studies that measure effects of GCs on more than one life‐history trait or in multiple environmental contexts, to test explicit hypotheses about how GCs and life‐history variation are related and (ii) the measurement of additional factors that modulate the effects of GCs on life‐history traits (e.g. GC receptors and binding protein levels) to better infer neurendocrine stress axis actions.

Conceptual models of HPA/I axis actions, such as allostatic load and reactive scope, to some extent explicitly predict the role of GCs in a life‐history context, but are descriptive in nature. We propose that GC effects on life‐history transitions, survival probabilities and fecundity can be modelled in existing quantitative demographic frameworks to improve our understanding of how GC variation influences life‐history evolution and GC‐mediated effects on population dynamics
Invading with biological weapons: the importance of disease‐mediated invasions
Authors: Strauss Alex , White Andy , Boots Mike
Published: November 2012

Invasive organisms and emerging wildlife disease pose two of the greatest threats to global biodiversity and ecosystem functioning.

Typically, when parasites are considered in invasion biology, it is in the context of the enemy release hypothesis, wherein a non‐indigenous species has greater probability of invasion success by virtue of leaving its natural enemies, including parasites, behind.

It is also possible that native parasites may prevent invasions, but it is clear that invasive organisms may bring infectious diseases with them that can infect native competitors (via spillover), or act as competent hosts for native diseases, increasing disease prevalence among native species (via spillback).

If the shared disease (either via spillover or spillback) has higher virulence in the native host (which is particularly likely with introduced parasites), there is the potential that the disease can act as a ‘biological weapon’ leading to a disease‐mediated invasion (DMI).

Here, we review cases where disease may have been an important factor mediating a wide range of invasions in vertebrates, invertebrates and plants.

We then focus on the invasion of the grey squirrel into the UK as a case study of a DMI, and we discuss how mathematical models have helped us to understand the importance of this shared disease and its implications for the management of invasive species.

We conclude that (i) DMIs are a widespread phenomenon, that (ii) spillover is more common in animal invasions and spillback more common among plant invasions and that (iii) spillover DMIs are particularly important in explaining the replacement of native animals with phylogenetically similar non‐indigenous species.
Effects of social immunity and unicoloniality on host–parasite interactions in invasive insect societies
Authors: Ugelvig Line V. , Cremer Sylvia
Published: November 2012

Social insects have a very high potential to become invasive pest species. Here, we explore how their social lifestyle and their interaction with parasites may contribute to this invasive success.

Similar to solitary species, parasite release followed by the evolution of increased competitive ability can promote establishment of introduced social insect hosts in their introduced range.

Genetic bottlenecks during introduction of low numbers of founder individuals decrease the genetic diversity at three levels: the population, the colony and the individual, with the colony level being specific to social insects. Reduced genetic diversity can affect both the individual immune system and the collective colony‐level disease defences (social immunity). Still, the dual immune system is likely to make social insects more robust to parasite attack.

Changes in social structure from small, family‐based, territorially aggressive societies in native populations towards huge networks of cooperating nests (unicoloniality) occur in some invasive social insects, for example, most invasive ants and some termites.

Unicoloniality is likely to affect disease dynamics in multiple ways. The free exchange of individuals within the population leads to an increased genetic heterogeneity among individuals of a single nest, thereby decreasing disease transmission. However, the multitude of reproductively active queens per colony buffers the effect of individual diseased queens and their offspring, which may result in a higher level of vertical disease transmission in unicolonial societies. Lastly, unicoloniality provides a competitive advantage over native species, allowing them to quickly become the dominant species in the habitat, which in turn selects for parasite adaptation to this common host genotype and thus eventually a high parasite pressure.

Overall, invasions by insect societies are characterized by general features applying to all introduced species, as well as idiosyncrasies that emerge from their social lifestyle. It is important to study these effects in concert to be able to develop efficient management and biocontrol strategies.
Implications of floral orientation for flight kinematics and metabolic expenditure of hover‐feeding hummingbirds
Authors: Sapir Nir , Dudley Robert
Published: November 2012

Nectar‐bearing flowers are characterized by many different shapes, sizes and orientations, which may affect the way hummingbirds feed from them. Many hummingbird‐pollinated flowers are oriented downwards, thereby requiring that trochilids feed while hovering with the bill oriented vertically upward.

We measured body orientations, wingbeat kinematics and hovering metabolic rates for Anna's Hummingbirds (Calypte anna) feeding from artificial flowers that were oriented horizontally, tilted 45° downwards and pointing vertically downwards.

When feeding from vertically oriented flowers, hummingbirds employed an upright body position combined with dorsal head flexion. Additional kinematic adjustments included an increased stroke plane angle relative to the longitudinal body axis and an increased stroke amplitude deriving from increases in the minimum positional angle of the wingbeat.

By contrast, wingbeat frequency, the stroke plane angle relative to horizontal, the ratio of the minimum to maximum positional angles of the wingbeat and the upstroke/downstroke ratio did not vary during feeding from different flower orientations.

Metabolic rates increased by an average (±SD) of 10·8 (±8·8)% for feeding from vertically compared to horizontally oriented flowers.

Feeding from pendent flowers comes with a substantial metabolic cost that may influence floral selection by hummingbirds and thus the evolution of associated pollination syndromes.
Control and host‐dependent activation of insect toxin expression in a root‐associated biocontrol pseudomonad
Authors: Péchy‐Tarr Maria , Borel Naomi , Kupferschmied Peter , Turner Vincent , Binggeli Olivier , Radovanovic Dragica , Maurhofer Monika , Keel Christoph
Published: November 2012

Pseudomonas fluorescens CHA0 is a root‐associated biocontrol agent that suppresses soil‐borne fungal diseases of crops. Remarkably, the pseudomonad is also endowed with systemic and oral activity against pest insects which depends on the production of the insecticidal Fit toxin. The toxin gene (fitD) is part of a virulence cassette encoding three regulators (FitF, FitG, FitH) and a type I secretion system (FitABC‐E). Immunoassays with a toxin‐specific antibody and transcriptional analyses involving fitG and fitH deletion and overexpression mutants identified LysR family regulator FitG and response regulator FitH as activator and repressor, respectively, of Fit toxin and transporter expression. To visualize and quantify toxin expression in single live cells by fluorescence microscopy, we developed reporters which in lieu of the native toxin protein express a fusion of the Fit toxin with red fluorescent mCherry. In a wild‐type background, expression of the mCherry‐tagged Fit toxin was activated at high levels in insect hosts, i.e. when needed, yet not on plant roots or in batch culture. By contrast, a derepressed fitH mutant expressed the toxin in all conditions. P. fluorescens hence can actively induce insect toxin production in response to the host environment, and FitH and FitG are key regulators in this mechanism.
Reputations and Research Quality in British Political Science: The Importance of Journal and Publisher Rankings in the 2008 RAE
Authors: Allen Nicholas , Heath Oliver
Published: November 2012

Research Highlights and Abstract

The article seeks to make a contribution in the following areas:

Departments that submitted a large proportion of books published with a top university press tended to do much better in the 2008 Research Assessment Exercise (RAE), especially in respect of their 4* rating. Departments that submitted large numbers of top-10 journal articles as a proportion of their outputs tended to get higher 4* ratings than departments that submitted only a few. Departments that had a member of staff on the RAE sub-panel saw their 4* rating jump considerably, all other things being equal, suggesting inadequate communication by the sub-panel of its working methods and criteria. The RAE sub-panel's judgements about research quality broadly reflected the judgements of the profession.

This article analyses the results of the 2008 Research Assessment Exercise (RAE). It demonstrates that the reputations of political science journals and scholarly publishers can explain the performance of institutions submitted to the RAE's Politics and International Studies sub-panel, and that there were also clear relationships between types of output and research quality. Outputs in top journals and with top presses were strongly associated with 4* quality and research excellence. Moreover, press and journal reputations appeared to have a greater impact than the type of publication. These findings should encourage policy makers to consider more cost-effective and efficient ways of evaluating research.
Accuracy of endoscopic ultrasound‐guided fine needle aspiration cytology on the differentiation of malignant and benign pancreatic cystic lesions: A single‐center experience
Authors: Oguz Dilek , Öztaş Erkin , Kalkan Ismail Hakkı , Tayfur Oyku , Cicek Bahattin , Aydog Gulden , Kurt Mevlut , Beyazit Yavuz , Etik Digdem , Nadir Isilay , Sahin Burhan
Published: November 2012

Objectives

The aim was to compare the use of endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) in cytology and the biochemical analysis of cyst fluid, together with the size of the lesion in the differentiation between benign and malignant pancreatic cystic lesions.

Methods

Data of patients who underwent EUS‐FNA for pancreatic cystic lesions in our center from January 2006 to October 2010 were retrospectively analyzed. The diagnostic accuracy of EUS‐FNA was determined.

Results

Of the 56 patients, 37 (66.1%) had evaluable cytology for diagnosis and sufficient cyst fluid was available for biochemical analysis in 58.9% (33/56) of the patients. The sensitivity, specificity, positive predictive value and negative predictive value of EUS‐FNA for detecting malignancy were 63%, 100%, 100% and 85%, respectively. EUS‐FNA was the most accurate diagnostic method for differentiating malignant and benign pancreatic cystic lesions (88%). Cyst fluid carcinoembryonic antigen (CEA) > 365 ng/mL had a sensitivity of 100% for the detection of malignant cystic lesions.

Conclusions

Although the rate of insufficient cyst fluid aspiration is high, the combination of cytological evaluation and CEA analysis of cyst fluid obtained by EUS‐FNA is accurate in differentiating malignant cystic lesions from benign ones. Safe techniques are essential to improve the yield of cyst fluid aspiration by EUS.
Presence‐only modelling using MAXENT: when can we trust the inferences?
Authors: Yackulic Charles B. , Chandler Richard , Zipkin Elise F. , Royle J. Andrew , Nichols James D. , Campbell Grant Evan H. , Veran Sophie
Published: November 2012

Recently, interest in species distribution modelling has increased following the development of new methods for the analysis of presence‐only data and the deployment of these methods in user‐friendly and powerful computer programs. However, reliable inference from these powerful tools requires that several assumptions be met, including the assumptions that observed presences are the consequence of random or representative sampling and that detectability during sampling does not vary with the covariates that determine occurrence probability.

Based on our interactions with researchers using these tools, we hypothesized that many presence‐only studies were ignoring important assumptions of presence‐only modelling. We tested this hypothesis by reviewing 108 articles published between 2008 and 2012 that used the MAXENT algorithm to analyse empirical (i.e. not simulated) data. We chose to focus on these articles because MAXENT has been the most popular algorithm in recent years for analysing presence‐only data.

Many articles (87%) were based on data that were likely to suffer from sample selection bias; however, methods to control for sample selection bias were rarely used. In addition, many analyses (36%) discarded absence information by analysing presence–absence data in a presence‐only framework, and few articles (14%) mentioned detection probability. We conclude that there are many misconceptions concerning the use of presence‐only models, including the misunderstanding that MAXENT, and other presence‐only methods, relieve users from the constraints of survey design.

In the process of our literature review, we became aware of other factors that raised concerns about the validity of study conclusions. In particular, we observed that 83% of articles studies focused exclusively on model output (i.e. maps) without providing readers with any means to critically examine modelled relationships and that MAXENT's logistic output was frequently (54% of articles) and incorrectly interpreted as occurrence probability.

We conclude with a series of recommendations foremost that researchers analyse data in a presence–absence framework whenever possible, because fewer assumptions are required and inferences can be made about clearly defined parameters such as occurrence probability.
Body image and psychological outcome after severe skin and soft tissue infection requiring intensive care
Authors: HELLGREN E. M. , LAGERGREN P. , LARSSON A. C. , SCHANDL A. R. , SACKEY P. V.
Published: November 2012

Background

Patients with severe skin and soft tissue infection (SSTI) requiring intensive care unit (ICU) stay are commonly treated with antibiotics, surgery and in some centers also with hyperbaric oxygen therapy. Long‐term follow‐up of body image and psychological outcome has not been described despite extensive surgery, potentially altered body image and subsequent psychological problems. The aim was to describe perceived body image and its relation to anxiety, depression and post‐traumatic stress disorder (PTSD)‐related symptoms in patients with severe SSTI 1 year after ICU stay. Specifically, we aimed to assess potential differences related to gender and anatomic site of infection.

Methods

Fifty patients treated for severe SSTI in the General ICU, Karolinska University Hospital 2008–2010 received the body image scale (BIS), impact of event scale (IES), and hospital anxiety and depression scale (HADS) 1 year after ICU discharge.

Results

Abdominoperineal SSTI was associated with more body image problems than other anatomic sites of infection in both men and women. Generally, women reported higher BIS scores than men (median 9.5 vs. 3.0 of total 30, P < 0.03) indicating more negative body image. A substantial number of patients reported scar dissatisfaction (63.9%), body dissatisfaction (51.1%) and body feeling less whole (51.0%). BIS scores correlated with HADS anxiety (r = 0.59, P < 0.01), depression (r = 0.60, P < 0.01) and IES (r = 0.61, P < 0.01) scores.

Conclusion

One year after severe SSTI requiring intensive care, women and patients with abdominoperineal SSTI reported significantly more body image problems. Negative body image was associated with anxiety, depression and PTSD‐related symptoms. Specific follow‐up for SSTI patients is warranted.
Nociceptive stimuli responses at different levels of general anaesthesia and genetic variability
Authors: STORM H. , STØEN R. , KLEPSTAD P. , SKORPEN F. , QVIGSTAD E. , RÆDER J.
Published: November 2012

Background

Changes in skin conductance (SC), clinical stress score (CSS), the bispectral index spectroscopy (BIS) index and the variation in the BIS index may be used to monitor responses to nociceptive stimuli. We wanted to examine these methods during noxious stimulation during general anaesthesia and if the responses were associated with variability in genes related to pain.

Methods

Sixty patients, given propofol to a BIS level of 40–50, were stimulated with standardised tetanic electrical stimuli during propofol infusion, plasma level of 3 μg/ml alone, or together with remifentanil target plasma level of 3 ng/ml or 10 ng/ml. The CSS, SC, BIS index and the variability of the BIS index were registered. The inter‐individual variation in nociceptive responses was analysed for co‐variation with genotypes of 89 single nucleotide polymorphisms from 23 candidate genes.

Results

During tetanic stimuli, CSS and SC increased significantly and were attenuated with increasing level of remifentanil, different from the BIS index and the variation in the BIS index. Polymorphisms in the P‐glycoprotein (ABCB1), tachykinin 1 receptor (TACR1), dopamine receptor D3 (DRD3) and beta arrestin 2 (ARRB2) genes were associated with the co‐variation in SC variables or CSS response or both during standardised nociceptive stimuli (P < 0.05). Because of no corrections for multiple testing, the genetic analyses are explorative, and associations must be tested in further studies.

Conclusion

This exploratory study suggests genes that may be tested further with relation to nociceptive response during anaesthesia. SC and CSS may be useful tools for monitoring nociceptive response during general anaesthesia.
Evaluating the effectiveness of five sampling methods for detection of the tomato potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Psylloidea: Triozidae)
Authors: Yen Alan L , Madge David G , Berry Nadine A , Yen Jian D L
Published: November 2012

One of the challenges in detecting a pest incursion is the selection of an appropriate sampling technique that is relatively easy to use and inexpensive. Five sampling techniques (sticky traps, water traps, sweep netting, vacuum sampling and direct searching) were used to detect the tomato potato psyllid (Bactericera cockerelli) in potato crops on the North Island of New Zealand. Sticky traps and water traps outperformed the other methods in detecting psyllids. There was weak evidence that water traps outperformed sticky traps, but this difference was minor. Sticky traps closer to the edge of a crop were more likely to catch more psyllids. The results suggest that surveillance for incursion by B. cockerelli into Australia using yellow sticky or water traps would be easier and more time‐effective to implement than other methods and would provide a higher probability of detection if the psyllid was in fact present.
Energetic study of cardioplegic hearts under ischaemia/reperfusion and [Ca2+] changes in cardiomyocytes of guinea‐pig: mitochondrial role
Authors: Ragone M. I. , Torres N. S. , Consolini A. E.
Published: November 2012

Aim

To study the role of mitochondria in the recovery of guinea‐pig hearts exposed to high‐K+‐cardioplegia (CPG) and ischaemia/reperfusion (I/R)

Methods

We measured contractility and heat release in perfused guinea‐pig hearts and cytosolic and mitochondrial Ca2+ by epifluorescence and confocal microscopy in isolated cardiomyocytes loaded with Fluo‐4 or Rhod‐2.

Results

In hearts, CPG increased the postischaemic contractile recovery, and this was potentiated by the mNCX blocker clonazepam and the mKATP opener diazoxide, which also prevented the fall in muscle economy. Moreover, CPG prevented the stunning induced by ouabain, which was reduced by clonazepam. In cardiomyocytes, CPG increased fluorescent signals of cytosolic and mitochondrial Ca2+, while the addition of a mNCX blocker (CGP37157) increased cytosolic but reduced mitochondrial [Ca2+]. Ouabain in CPG increased cytosolic Ca2+ and resting heat, but the addition of CGP37157 reduced them, as well as mitochondrial Ca2+.

Conclusions

CPG, diazoxide and clonazepam improve postischaemic recovery, respectively, by increasing the Ca2+ cycling and by reducing the mitochondrial Ca2+ uptake either by uniporter or by mNCX. The mitochondria compete with the leaky sarcoplasmic reticulum (SR) as sink of Ca2+ in guinea‐pig hearts, affecting the postischaemic contractility. CPG also prevented the ouabain‐induced dysfunction by avoiding the Ca2+ overload. Ouabain reduced the synergism between CPG and clonazepam suggesting that [Na+]i and SR load influence the mNCX role.
Central role of mitochondrial injury in the pathogenesis of acute pancreatitis
Authors: Maléth J. , Rakonczay Z. , Venglovecz V. , Dolman N. J. , Hegyi P.
Published: November 2012

Acute pancreatitis is an inflammatory disease with no specific treatment. One of the main reasons behind the lack of specific therapy is that the pathogenesis of acute pancreatitis is poorly understood. During the development of acute pancreatitis, the disease‐inducing factors can damage both cell types of the exocrine pancreas, namely the acinar and ductal cells. Because damage of either of the cell types can contribute to the inflammation, it is crucial to find common intracellular mechanisms that can be targeted by pharmacological therapies. Despite the many differences, recent studies revealed that the most common factors that induce pancreatitis cause mitochondrial damage with the consequent breakdown of bioenergetics, that is, ATP depletion in both cell types. In this review, we summarize our knowledge of mitochondrial function and damage within both pancreatic acinar and ductal cells. We also suggest that colloidal ATP delivery systems for pancreatic energy supply may be able to protect acinar and ductal cells from cellular damage in the early phase of the disease. An effective energy delivery system combined with the prevention of further mitochondrial damage may, for the first time, open up the possibility of pharmacological therapy for acute pancreatitis, leading to reduced disease severity and mortality.
The discovery of a new class of synaptic transmitters in smooth muscle 50 years ago and amelioration of coronary artery thrombosis
Authors: Bennett M. R.
Published: November 2012

Clopidogrel and ticagrelor, antagonists to P2Y12 receptor molecules on platelet membranes, significantly ameliorate acute myocardial infarction due to coronary artery thrombosis, the most common cause of death in the developed world. A personal account is given here of the foundational research that lead to the identification of P2Y receptors, carried out 50 years ago in the Melbourne University Zoology Department headed by Geoffrey Burnstock. In Christmas 1962, I made the serendipitous observation of large hyperpolarizing changes across the membranes of smooth muscle cells in the taenia coli of the intestine on stimulating its nerve supply. I then showed that these potentials relaxed the muscle and were not due to noradrenaline or acetylcholine, which were then the only substances known to be released from nerves. I called these non‐adrenergic, non‐cholinergic (NANC) terminals in the laboratory and showed that this NANC transmitter acted at receptor molecules on the muscle cells, promoting efflux of potassium ions, and so the observed potential changes. In 1968, Graeme Campbell showed that ATP relaxed the taenia coli muscle, and in 1969, David Satchell, using purine chromatography, showed that ATP was likely to be released from NANC terminals. The receptor molecules involved were shown to be exceptionally sensitive to 2‐methylthio‐ATP (Satchell and Macguire, 1975, J Pharmacol Exp Ther, 195, 540), and so belonged to the class P2Y receptors as designated by Abbracchio and Burnstock, with subclasses P2Y1–P2Y12. The discovery of the role of P2Y12 receptors in increasing thrombosis lead to the focused research that resulted in clopidogrel and ticagrelor.
Heat stress activates the Akt/mTOR signalling pathway in rat skeletal muscle
Authors: Yoshihara T. , Naito H. , Kakigi R. , Ichinoseki‐Sekine N. , Ogura Y. , Sugiura T. , Katamoto S.
Published: November 2012

Aim

It is well known that various stimuli, such as mechanical stress and nutrients, induce muscle hypertrophy thorough the Akt/mTOR signalling pathway, which is a key mediator of protein synthesis and hypertrophy in skeletal muscle. It was recently reported that heat stress also induces an increase in muscle weight and muscle protein content. In addition, heat stress enhances Akt/mTOR signalling after one bout of resistance exercise. However, it remains unclear whether increased temperature itself stimulates the Akt/mTOR signalling pathway.

Methods

Forty‐two male Wistar rats (279.5 ± 1.2 g) were divided into a control group (CON) or one of five thermal stress groups at 37, 38, 39, 40 or 41 °C (n = 7 each group). After overnight fasting, both legs were immersed in different temperatures of hot water for 30 min under sodium pentobarbital anaesthesia. The soleus and plantaris muscles were immediately removed from both legs after the thermal stress.

Results

The phosphorylation of mTOR or 4E‐BP1 and heat shock protein (HSP) expression levels were similar among groups in both the soleus and plantaris muscles. However, Akt and p70S6K phosphorylation significantly increased at 41 °C in the soleus and plantaris muscles. Moreover, we observed a temperature‐dependent increase in Akt and p70S6K phosphorylation in both muscles.

Conclusion

Our data indicate that the altered temperature increased phosphorylation in a temperature‐dependent manner in rat skeletal muscle and may itself be a key stimulator of Akt/mTOR signalling.