bluuebunny/crossref_metadata_2025 huggingface dataset:
The natural regeneration of calcareous grassland at a landscape scale: 150 years of plant community re‐assembly on Salisbury Plain, UK
Authors: Redhead John W. , Sheail John , Bullock James M. , Ferreruela Andrea , Walker Kevin J. , Pywell Richard F.
Published: November 2013

Questions

What is the time‐scale for natural regeneration of calcareous grassland? Is this time‐scale the same for individual plant species, plant community composition and functional traits?

Location

Defence Training Estate Salisbury Plain, Wiltshire, UK.

Methods

We investigated the rate of natural regeneration of species‐rich calcareous grassland across a 20 000‐ha landscape. We combined a large‐scale botanical survey with historic land‐use data (6–150 yrs before present) and examined differences between grassland age classes in the occurrence of individual plant species, plant community composition and plant community functional traits.

Results

Many species showed a significant association with grasslands over 100 yrs old. These included the majority of those defined elsewhere as calcareous grassland indicators, although some appeared on grasslands <10 yrs old. Plant community composition showed increasing similarity to the oldest grasslands with increased grassland age, with the exception of very recently ex‐agricultural grasslands. Most functional traits showed clear trends with grassland age, with dispersal ability differing most strongly between recent and older grasslands, whilst soil fertility and pH tolerance were more influential over longer time‐scales.

Conclusions

Even in a well connected landscape, natural regeneration to a community resembling ancient calcareous grassland in terms of functional traits and plant community composition takes over a century, although changes at the level of individual species may occur much earlier. These findings confirm the uniqueness of ancient calcareous grassland. They also suggest that the targets of re‐establishment efforts should be adjusted to account for the likely time‐scale of full community re‐assembly.
Community‐acquired infections associated with increased risk of lymphoplasmacytic lymphoma/Waldenström macroglobulinaemia
Authors: McShane Charlene M. , Murray Liam J. , Engels Eric A. , Anderson Lesley A.
Published: November 2013

Emerging evidence supports the role of immune stimulation in the development of lymphoplasmacytic lymphoma/Waldenström Macroglobulinaemia (LPL/WM). Using the population‐based Surveillance, Epidemiology End Results‐Medicare database we investigated the exposure to 14 common community‐acquired infections and subsequent risk of LPL/WM in 693 LPL/WM cases and 200 000 controls. Respiratory tract infections, bronchitis [odds ratio (OR) 1·56], pharyngitis (OR 1·43), pneumonia (OR 1·42) and sinusitis (OR 1·33) and skin infection, herpes zoster (OR 1·51) were all significantly associated with subsequent increased risk of LPL/WM. For each of these infections, the findings remained significantly elevated following the exclusion of more than 6 years of Medicare claims data prior to LPL/WM diagnosis. Our findings may support a role for infections in the development of LPL/WM or could reflect an underlying immune disturbance that is present several years prior to diagnosis and thereby part of the natural history of disease progression.
Predicting ease of perinephric fat dissection at time of open partial nephrectomy using preoperative fat density characteristics
Authors: Zheng Yin , Espiritu Patrick , Hakky Tariq , Jutras Kristin , Spiess Philippe E.
Published: November 2013

Objective

To predict the ease of perinephric fat surgical dissection at the time of open partial nephrectomy (OPN) using perinepheric fat density characteristics as measured on preoperative computed tomography (CT).

Patients and Methods

In all, 41 consecutive OPN patients with available preoperative imaging and prospectively collected dissection difficulty assessment were identified. Using a scoring system that was adopted for the purposes of this study, the genitourinary surgeon quantified the difficulty of the perinephric fat dissection on the surface of the renal capsule at the time of surgery. On axial CT slice centred on the renal hilum, we measured the quantity and density of perinephric fat whose absorption coefficient was between –190 to –30 Hounsfield units. Correlation between perinephric fat surface density (PnFSD) as noted on preoperative imaging and as observed by the surgeon at time of surgery were correlated in a completely ‘double‐blinded’ fashion. Density comparisons between fat dissection difficulties were made using an anova. Associations between covariates and perinephric fat density were evaluated by univariate and multivariate logistic regression analyses. Receiver‐operating characteristic (ROC) curves for six different predictive models were created to visualise the predictive enhancement of PnFSD.

Results

PnFSD was positively correlated with total surgical duration (Pearson's correlation coefficient 0.314, P = 0.04). PnFSD significantly correlated with gender (P = 0.001) and difficulty of perinephric fat surgical dissection (P < 0.001) scores. The mean (sd) PnFSD for a dissection that was not difficult (n = 19) was 5598.32 (1367.77) surface density pixel unit (SDPU), and for a difficult dissection (n = 22) was 10272.23 (3804.67) SDPU. Univariate analysis showed gender (P = 0.002), and PnFSD were predictive of the presence of ‘sticky’ perinephric fat. A multivariate analysis model showed that PnFSD was the only variable that remained an independent predictor of perinephric fat dissection difficulty (P = 0.01). Of the six ROC models assessed, only PnFSD had a significant capability to predict the difficulty of the perinephric fat dissection due to the presence of highly adherent ‘sticky’ fat, with an area under the curve of 0.87 (P < 0.001).

Conclusion

Accurate preoperative assessment of perinephric fat density constitutes a strong indicator of perioperative fat dissection difficulty. Perinephric fat densities can be practically obtained from preoperative CT to identify ‘sticky’ fat, which may help determine the anticipated ease of surgical dissection, which can guide education, preoperative surgical planning, and potentially the surgical approach offered to patients.
Prevalence of dyslipidaemia in patients with renal cell carcinoma: a case‐control study in China
Authors: Zhang Gui‐Ming , Zhu Yao , Luo Lei , Zhang Hai‐Liang , Gu Cheng‐Yuan , Sun Li‐Jiang , Ye Ding‐Wei
Published: November 2013

Objective

To examine the prevalence of dyslipidaemia in patients with renal cell carcinoma (RCC) in a Chinese population.

Patients and Methods

In all, 550 histologically confirmed RCC cases and 570 controls, matched for age and sex were included. Total cholesterol, triglyceride, low‐density lipoprotein (LDL) and high‐density lipoprotein (HDL) were assessed before treatment using standard techniques. The lipid profiles were defined as ‘normal’, ‘borderline high’, ‘high’ and ‘low’ according to Chinese Guidelines on Adult Dyslipidaemia. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression in both unadjusted and adjusted models.

Results

Abnormal LDL elevation was common in RCC cases compared with controls (P < 0.001). Results for total cholesterol, triglyceride and HDL levels between groups were insignificant. The OR for RCC for high levels of LDL (≥160 mg/dL) compared with those with a normal LDL profile was 4.675 (95% CI 1.900–11.500). After adjustment for age, gender, body mass index, smoking status, hypertension, diabetes, total cholesterol and triglyceride, the coexistence of high levels of LDL and RCC was large and statistically significant (OR 8.955, 95% CI 3.371–23.786). There was a significant coexistence of RCC for participants with high LDL levels when subgroups of cases with clear cell subtypes and advanced T stages were compared with controls.

Conclusion

Abnormal LDL elevation was prevalent in Chinese patients with RCC. The results remain to be evaluated in prospective cohorts.
The Cancer of the Prostate Risk Assessment (CAPRA) score predicts biochemical recurrence in intermediate‐risk prostate cancer treated with external beam radiotherapy (EBRT) dose escalation or low‐dose rate (LDR) brachytherapy
Authors: Krishnan Vimal , Delouya Guila , Bahary Jean‐Paul , Larrivée Sandra , Taussky Daniel
Published: November 2013

Objective

To study the prognostic value of the University of California, San Francisco Cancer of the Prostate Risk Assessment (CAPRA) score to predict biochemical failure (bF) after various doses of external beam radiotherapy (EBRT) and/or permanent seed low‐dose rate (LDR) prostate brachytherapy (PB).

Patients and Methods

We retrospectively analysed 345 patients with intermediate‐risk prostate cancer, with PSA levels of 10–20 ng/mL and/or Gleason 7 including 244 EBRT patients (70.2–79.2 Gy) and 101 patients treated with LDR PB. The minimum follow‐up was 3 years. No patient received primary androgen‐deprivation therapy. bF was defined according to the Phoenix definition. Cox regression analysis was used to estimate the differences between CAPRA groups.

Results

The overall bF rate was 13% (45/345). The CAPRA score, as a continuous variable, was statistically significant in multivariate analysis for predicting bF (hazard ratio [HR] 1.37, 95% confidence interval [CI] 1.10–1.72, P = 0.006). There was a trend for a lower bF rate in patients treated with LDR PB when compared with those treated by EBRT ≤ 74 Gy (HR 0.234, 95% CI 0.05–1.03, P = 0.055) in multivariate analysis. In the subgroup of patients with a CAPRA score of 3–5, CAPRA remained predictive of bF as a continuous variable (HR 1.51, 95% CI 1.01–2.27, P = 0.047) in multivariate analysis.

Conclusion

The CAPRA score is useful for predicting biochemical recurrence in patients treated for intermediate‐risk prostate cancer with EBRT or LDR PB. It could help in treatment decisions.
Comparing score tests and other local dependence diagnostics for the graded response model
Authors: Liu Yang , Thissen David
Published: November 2013

Score tests for identifying locally dependent item pairs have been proposed for binary item response models. In this article, both the bifactor and the threshold shift score tests are generalized to the graded response model. For the bifactor test, the generalization is straightforward; it adds one secondary dimension associated only with one pair of items. For the threshold shift test, however, multiple generalizations are possible: in particular, conditional, uniform, and linear shift tests are discussed in this article. Simulation studies show that all of the score tests have accurate Type I error rates given large enough samples, although their small‐sample behaviour is not as good as that of Pearson's Χ2andM2as proposed in other studies for the purpose of local dependence (LD) detection. All score tests have the highest power to detect theLDwhich is consistent with their parametric form, and in this case they are uniformly more powerful than Χ2andM2; even wrongly specified score tests are more powerful than Χ2andM2in most conditions. An example using empirical data is provided for illustration.
Antiplatelet activity of nifedipine is mediated by inhibition of NF‐κB activation caused by enhancement of PPAR‐β/‐γ activity
Authors: Shih Ching‐Yu , Lin I‐Hsin , Ding James‐Cheng , Chen Fu‐Chi , Chou Tz‐Chong
Published: November 2013

Background and Purpose

The transcription factor NF‐κB, stimulates platelet aggregation through a non‐genomic mechanism. Nifedipine, a voltage‐gated L‐type calcium channel blocker, is widely used to treat hypertension. Nifedipine also displays antiplatelet activity, but the underlying mechanisms involved remain unclear. This study was designed to investigate whether the antiplatelet effects of nifedipine are mediated by regulating NF‐κB‐dependent responses.

Experimental Approach

Platelet aggregation was measured turbidimetrically using an aggregometer. NF‐κB and PPAR activation, intracellular Ca2+ mobilization, PKCα activity, surface glycoprotein IIb/IIIa (GPIIb/IIIa) expression and platelet activation‐related signalling pathways were determined in control and nifedipine‐treated platelets in the presence or absence of PPAR antagonists or betulinic acid, a NF‐κB activator.

Key Results

Exposure of platelets to nifedipine significantly increased the PPAR‐β/‐γ activity in activated human platelets. Treatment with nifedipine reduced collagen‐induced NF‐κB events, including the phosphorylation of IκB kinase‐β, IκBα and p65NF‐κB, which were markedly attenuated by GSK0660, a PPAR‐β antagonist, or GW9662, a PPAR‐γ antagonist. Furthermore, the interaction of PPAR‐β/‐γ with NF‐κB and the PPAR‐β/‐γ‐up‐regulated NO/cGMP/PKG1 cascade may contribute to inhibition of NF‐κB activation by nifedipine. Suppressing PPAR‐β/‐γ activity or increasing NF‐κB activation greatly reversed the inhibitory effect of nifedipine on collagen‐induced platelet aggregation, intracellular Ca2+ mobilization, PKCα activity and surface GPIIb/IIIa expression.

Conclusions and Implications

PPAR‐β/‐γ‐dependent inhibition of NF‐κB activation contributes to the antiplatelet activity of nifedipine. These findings provide a novel mechanism underlying the beneficial effects of nifedipine on platelet hyperactivity‐related vascular and inflammatory diseases.
Activation and inhibition of transient receptor potential TRPM3‐induced gene transcription
Authors: Lesch Andrea , Rubil Sandra , Thiel Gerald
Published: November 2013

Background and Purpose

Transient receptor potential‐3 (TRPM3) channels function as Ca2+ permeable cation channels. While the natural ligands for these channels are still unknown, several compounds have been described that either activate or inhibit TRPM3 channel activity.

Experimental Approach

We assessed TRPM3‐mediated gene transcription, which relies on the induction of intracellular signalling to the nucleus following activation of TRPM3 channels. Activator protein‐1 (AP‐1) and Egr‐1‐responsive reporter genes were integrated into the chromatin of the cells. This strategy enabled us to analyse gene transcription of the AP‐1 and Egr‐1‐responsive reporter genes that were packed into an ordered chromatin structure.

Key Results

The neurosteroid pregnenolone sulfate strikingly up‐regulated AP‐1 and Egr‐1 transcriptional activity, while nifedipine and D‐erythro‐sphingosine, also putative activators of TRPM3 channels, exhibited either no or TRPM3‐independent effects on gene transcription. In addition, pregnenolone sulfate robustly enhanced the transcriptional activation potential of the ternary complex factor Elk‐1. Pregnenolone sulfate‐induced activation of gene transcription was blocked by treatment with mefenamic acid and, to a lesser extent, by the polyphenol naringenin. In contrast, progesterone, pregnenolone and rosiglitazone reduced AP‐1 activity in the cells, but had no inhibitory effect on Egr‐1 activity in pregnenolone sulfate‐stimulated cells.

Conclusion and Implications

Pregnenolone sulfate is a powerful activator of TRPM3‐mediated gene transcription, while transcription is completely inhibited by mefenamic acid in cells expressing activated TRPM3 channels. Both compounds are valuable tools for further investigating the biological functions of TRPM3 channels.

Linked Articles

This article is part of a themed section on the pharmacology of TRP channels. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue‐10
Hypotensive effects of ghrelin receptor agonists mediated through a novel receptor
Authors: Callaghan Brid , Kosari Samin , Pustovit Ruslan V. , Sartor Daniela M , Ferens Dorota , Ban Kung , Baell Jonathan , Nguyen Trung V , Rivera Leni R , Brock James A , Furness John B
Published: November 2013

Background and Purpose

Some agonists of ghrelin receptors cause rapid decreases in BP. The mechanisms by which they cause hypotension and the pharmacology of the receptors are unknown.

Experimental Approach

The effects of ligands of ghrelin receptors were investigated in rats in vivo, on isolated blood vessels and on cells transfected with the only molecularly defined ghrelin receptor, growth hormone secretagogue receptor 1a (GHSR1a).

Key Results

Three agonists of GHSR1a receptors, ulimorelin, capromorelin and CP464709, caused a rapid decrease in BP in the anaesthetized rat. The effect was not reduced by either of two GHSR1a antagonists, JMV2959 or YIL781, at doses that blocked effects on colorectal motility, in vivo. The rapid hypotension was not mimicked by ghrelin, unacylated ghrelin or the unacylated ghrelin receptor agonist, AZP531. The early hypotension preceded a decrease in sympathetic nerve activity. Early hypotension was not reduced by hexamethonium or by baroreceptor (sino‐aortic) denervation. Ulimorelin also relaxed isolated segments of rat mesenteric artery, and, less potently, relaxed aorta segments. The vascular relaxation was not reduced by JMV2959 or YIL781. Ulimorelin, capromorelin and CP464709 activated GHSR1a in transfected HEK293 cells at nanomolar concentrations. JMV2959 and YIL781 both antagonized effects in these cells, with their pA2 values at the GHSR1a receptor being 6.55 and 7.84.

Conclusions and Implications

Our results indicate a novel vascular receptor or receptors whose activation by ulimorelin, capromorelin and CP464709 lowered BP. This receptor is activated by low MW GHSR1a agonists, but is not activated by ghrelin.
Changes in mitochondrial function are pivotal in neurodegenerative and psychiatric disorders: How important is BDNF?
Authors: Markham A , Bains R , Franklin P , Spedding M
Published: November 2013

The brain is at the very limit of its energy supply and has evolved specific means of adapting function to energy supply, of which mitochondria form a crucial link. Neurotrophic and inflammatory processes may not only have opposite effects on neuroplasticity, but also involve opposite effects on mitochondrial oxidative phosphorylation and glycolytic processes, respectively, modulated by stress and glucocorticoids, which also have marked effects on mood. Neurodegenerative processes show marked disorders in oxidative metabolism in key brain areas, sometimes decades before symptoms appear (Parkinson's and Alzheimer's diseases). We argue that brain‐derived neurotrophic factor couples activity to changes in respiratory efficiency and these effects may be opposed by inflammatory cytokines, a key factor in neurodegenerative processes.

Linked Articles

This article is part of a themed issue on Mitochondrial Pharmacology: Energy, Injury & Beyond. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2014.171.issue‐8
A GPU‐based Streaming Algorithm for High‐Resolution Cloth Simulation
Authors: Tang Min , Tong Ruofeng , Narain Rahul , Meng Chang , Manocha Dinesh
Published: November 2013

We present a GPU‐based streaming algorithm to perform high‐resolution and accurate cloth simulation. We map all the components of cloth simulation pipeline, including time integration, collision detection, collision response, and velocity updating to GPU‐based kernels and data structures. Our algorithm perform intra‐object and inter‐object collisions, handles contacts and friction, and is able to accurately simulate folds and wrinkles. We describe the streaming pipeline and address many issues in terms of obtaining high throughput on many‐core GPUs. In practice, our algorithm can perform high‐fidelity simulation on a cloth mesh with 2M triangles using 3GB of GPU memory. We highlight the parallel performance of our algorithm on three different generations of GPUs. On a high‐end NVIDIA Tesla K20c, we observe up to two orders of magnitude performance improvement as compared to a single‐threaded CPU‐based algorithm, and about one order of magnitude improvement over a 16‐core CPU‐based parallel implementation.
Constrainable Multigrid for Cloth
Authors: Jeon Inyong , Choi Kwang‐Jin , Kim Tae‐Yong , Choi Bong‐Ouk , Ko Hyeong‐Seok
Published: November 2013

We present a new technique which can handle both point and sliding constraints in the multigrid (MG) framework. Although the MG method can theoretically perform as fast as O(N), the development of a clothing simulator based on the MG method calls for solving an important technical challenge: handling the constraints. Resolving constrains has been difficult in MG because there has been no clear way to transfer the constraints existing in the finest level mesh to the coarser level meshes. This paper presents a new formulation based on soft constraints, which can coarsen the constraints defined in the finest level to the coarser levels. Experiments are performed which show that the proposed method can solve the linear system up to 4–9 times faster in comparison with the modified preconditioned conjugate gradient method (MPCG) without quality degradation. The proposed method is easy to implement and can be straightforwardly applied to existing clothing simulators which are based on implicit time integration.
Topology Aware Data‐Driven Inverse Kinematics
Authors: Ho Edmond S. L. , Shum Hubert P. H. , Cheung Yiu‐ming , Yuen P. C.
Published: November 2013

Creating realistic human movement is a time consuming and labour intensive task. The major difficulty is that the user has to edit individual joints while maintaining an overall realistic and collision free posture. Previous research suggests the use of data‐driven inverse kinematics, such that one can focus on the control of a few joints, while the system automatically composes a natural posture. However, as a common problem of kinematics synthesis, penetration of body parts is difficult to avoid in complex movements. In this paper, we propose a new data‐driven inverse kinematics framework that conserves the topology of the synthesizing postures. Our system monitors and regulates the topology changes using the Gauss Linking Integral (GUI), such that penetration can be efficiently prevented. As a result, complex motions with tight body movements, as well as those involving interaction with external objects, can be simulated with minimal manual intervention. Experimental results show that using our system, the user can create high quality human motion in real‐time by controlling a few joints using a mouse or a multi‐touch screen. The movement generated is both realistic and penetration free. Our system is best applied for interactive motion design in computer animations and games.
Second‐Order Approximation for Variance Reduction in Multiple Importance Sampling
Authors: Lu H. , Pacanowski R. , Granier X.
Published: November 2013

Monte Carlo Techniques are widely used in Computer Graphics to generate realistic images. Multiple Importance Sampling reduces the impact of choosing a dedicated strategy by balancing the number of samples between different strategies. However, an automatic choice of the optimal balancing remains a difficult problem. Without any scene characteristics knowledge, the default choice is to select the same number of samples from different strategies and to use them with heuristic techniques (e.g., balance, power or maximum). In this paper, we introduce a second‐order approximation of variance for balance heuristic. Based on this approximation, we introduce an automatic distribution of samples for direct lighting without any prior knowledge of the scene characteristics. We demonstrate that for all our test scenes (with different types of materials, light sources and visibility complexity), our method actually reduces variance in average. We also propose an implementation with low overhead for offline and GPU applications. We hope that this approach will help developing new balancing strategies.
Interactive Physics‐based Ink Splattering Art Creation
Authors: Lei Su‐Ian Eugene , Chen Ying‐Chieh , Chen Hsiang‐Ting , Chang Chun‐Fa
Published: November 2013

This paper presents an interactive system for ink splattering, a form of abstract art that artists splat ink onto the canvas. The default input device of our system is a pressure‐sensitive 2D stylus, the most common sketching tool for digital artists, and we propose two interaction mode:ink‐flicking modeandink‐dripping mode, that are designed to be analogous to the artistic techniques of ink splattering in real world. The core of our ink splattering system is a novel three‐stage ink splattering framework that simulates the physics‐based interaction of ink with different mediums including brush heads, air and paper. We have implemented the physical engine in CUDA and the whole simulation process runs at interactive speed.
Modeling by Drawing with Shadow Guidance
Authors: Fan Lubin , Wang Ruimin , Xu Linlin , Deng Jiansong , Liu Ligang
Published: November 2013

Modeling 3D objects is difficult, especially for the user who lacks the knowledge on 3D geometry or even on 2D sketching. In this paper, we present a novel sketch‐based modeling system which allows novice users to create 3D custom models by assembling parts based on a database of pre‐segmented 3D models. Different from previous systems, our system supports the user with visualized and meaningful shadow guidance under his strokes dynamically to guide the user to convey his design concept easily and quickly. Our system interprets the user's strokes as similarity queries into database to generate the shadow image for guiding the user's further drawing and returns the 3D candidate parts for modeling simultaneously. Moreover, our system preserves the high‐level structure in generated models based on prior knowledge pre‐analyzed from the database, and allows the user to create custom parts with geometric variations. We demonstrate the applicability and effectiveness of our modeling system with human subjects and present various models designed using our system.
The POP Buffer: Rapid Progressive Clustering by Geometry Quantization
Authors: Limper M. , Jung Y. , Behr J. , Alexa M.
Published: November 2013

Within this paper, we present a novel, straightforward progressive encoding scheme for general triangle soups, which is particularly well‐suited for mobile and Web‐based environments due to its minimal requirements on the client's hardware and software. Our rapid encoding method uses a hierarchy of quantization to effectively reorder the original primitive data into several nested levels of detail. The resulting stateless buffer can progressively be transferred as‐is to the GPU, where clustering is efficiently performed in parallel during rendering. We combine our approach with a crack‐free mesh partitioning scheme to obtain a straightforward method for fast streaming and basic view‐dependent LOD control.
Learning to Predict Localized Distortions in Rendered Images
Authors: Čadík Martin , Herzog Robert , Mantiuk Rafał , Mantiuk Radosław , Myszkowski Karol , Seidel Hans‐Peter
Published: November 2013

In this work, we present an analysis of feature descriptors for objective image quality assessment. We explore a large space of possible features including components of existing image quality metrics as well as many traditional computer vision and statistical features. Additionally, we propose new features motivated by human perception and we analyze visual saliency maps acquired using an eye tracker in our user experiments. The discriminative power of the features is assessed by means of a machine learning framework revealing the importance of each feature for image quality assessment task. Furthermore, we propose a new data‐driven full‐reference image quality metric which outperforms current state‐of‐theart metrics. The metric was trained on subjective ground truth data combining two publicly available datasets. For the sake of completeness we create a new testing synthetic dataset including experimentally measured subjective distortion maps. Finally, using the same machine‐learning framework we optimize the parameters of popular existing metrics.
Incorporating spatial constraints in different periods of the annual cycle improves species distribution model performance for a highly mobile bird species
Authors: Cardador Laura , Sardà‐Palomera Francesc , Carrete Martina , Mañosa Santi
Published: November 2013

Aim

The knowledge of both potential distribution and habitat suitability is fundamental for conservation planning and management of a variety of taxa world‐wide. Species distribution models (SDMs) are increasingly applied as predictive tools for these purposes. Such models are based on the concept of ecological niche and assume that species distribute themselves based on niche spaces defined by climate and habitat features. However, this assumption can be violated due to the existence of pure spatial range constraints, a factor rarely accounted for in SDMs, particularly for highly mobile species. We analyse whether pure distance effects, niche‐based environmental responses or a combination of both factors can play an important role in limiting the large‐scale distribution of highly mobile species.

Location

Spain, southern Europe.

Methods

We modelled the spatial distribution of an expanding raptor species, the marsh harrier Circus aeruginosus, in Spain. We implemented one conventional statistical method (generalized linear model) and one nonparametric technique (maximum entropy, Maxent) using a large dataset on marsh harrier occurrence (n = 1586) in two different periods of the annual cycle, that is breeding and wintering seasons. We developed models that included environmental variables and that either ignored or incorporated spatial constraints using spatial eigenvector mapping (spatial filters).

Results

By comparing model accuracy, we found evidence that the distribution of marsh harriers in Spain was spatially constrained beyond environmental variables and that the effect of spatial constraints varies depending on the period of their annual cycle.

Main conclusions

Contrary to the equilibrium postulate, our results support the prediction that environmental specializations do not necessarily result in complete habitat matching due to dispersal limitations. Thus, ignoring spatial constraints in SDMs can lead to misunderstandings of the ecological mechanisms that explain species range limits.
The stability of the Manual Ability Classification System over time
Authors: Öhrvall Ann‐Marie , Krumlinde‐Sundholm Lena , Eliasson Ann‐Christin
Published: November 2013

Aim

To evaluate the stability over time of the Manual Ability Classification System (MACS) levels.

Method

The study group comprised 1267 children with cerebral palsy (746 males, 521 females) who were followed from 2005 to 2010 with two or more registered MACS classifications rated at least 1 year apart. Thirty‐five percent of the children (n=445) had four MACS registrations. The children were between 4 and 17 years old at their first rating, The stability over time was also compared between children who were younger (4y of age) or older (≥10y) at the time of their first classification.

Results

An excellent stability was found between two ratings at 1‐year intervals with an intraclass correlation coefficient (ICC) of 0.97 (95% CI 0.97–0.97) and 82% agreement (n=1267). The stability was also excellent for two ratings performed 3 to 5 years apart (ICC 0.96; 95% CI 0.95–0.97) with an agreement of 78% (n=445). Across four ratings, 70% of the children remained at the same level. The results were similar for younger and older children, indicating that stability was not influenced by age.

Interpretation

This study provides evidence that MACS levels are stable over time and that the classification has predictive value.
Echocardiographic Examination of the Posterior Atrioventricular Groove
Authors: Silbiger Jeffrey J.
Published: November 2013

Abnormalities of the posterior atrioventricular (AV) groove may be mischaracterized or overlooked in the course of routine echocardiographic imaging. Vascular abnormalities in this location include plethora of the coronary sinus and ectasia of the circumflex coronary artery. Excess accumulation of calcium (mitral annular calcification) and of fat (lipomatosis of the posterior AV groove) may also occur in this region. Masses (tumors or thrombus) arising from the floor of the left atrium or extrinsic to it (hiatal hernia, lymph nodes) may occupy the posterior AV groove. Abnormalities of the left ventricle, including aneurysms and pseudoaneurysms may present as masses in the posterior AV groove. This article discusses the echocardiographic features, differential diagnosis, and clinical significance of these abnormalities.
Outcomes Following Surgical Correction of Pure Aortic Regurgitation in Presence or Absence of Significant Functional Mitral Regurgitation
Authors: MacHaalany Jimmy , Bertrand Olivier F. , Voisine Pierre , O'Connor Kim , Bernier Mathieu , Dubois‐Sénéchal Isaie‐Nicolas , Jacques Pierre‐Olivier , Viel Isabelle , Dubois Michelle , Sénéchal Mario
Published: November 2013

Background

Functional mitral regurgitation (MR) can occur secondary to severe aortic regurgitation (AR). However, data on the overall impact of mitral surgical intervention after aortic valve replacement (AVR) are scarce. We sought to study the left ventricular (LV) remodeling process and determine predictors of clinical outcomes of patients with pure severe AR in presence or absence of significant functional MR.

Methods

Patients were categorized into AR‐MR group (≤ mild MR; n = 51, 76%) and AR + MR group (≥ moderate MR; n = 16, 24%). All patients in the AR + MR group underwent AVR and MR correction. Serial echocardiographic measurements and clinical follow‐up up to 5 years were obtained in all patients.

Results

Significant reverse LV remodeling occurred in both groups compared with baseline. No 30‐day deaths occurred. Mortality and heart failure‐related hospitalization rates, at follow‐up, were significantly higher in the AR + MR group (19% vs. 2%, P = 0.04 and 38% vs. 12% P = 0.03, respectively), but a similar proportion of patients from both groups was in New York Heart Association class I or II (87% vs. 92%, P = 0.62). Preoperative indexed stroke volume (SV) <50 mL/m2 was the only independent predictor of death and/or rehospitalization after surgery (odds ratio: 61.1, [95% CI, 12.6–425.2]; P < 0.0001).

Conclusion

Despite being a higher risk population, patients with moderate‐to‐severe functional MR secondary to severe AR experience similar postoperative mortality at the expense of a moderately higher 5‐year overall mortality, rate of hospitalization for congestive heart failure, and medication use. Preoperative indexed SV < 50 mL/m2 may be helpful in predicting long‐term outcomes.
Feeding by sugarcane aphid, Melanaphis sacchari, on sugarcane cultivars with differential susceptibility and potential mechanism of resistance
Authors: Akbar W. , Showler A.T. , Reagan T.E. , Davis J.A. , Beuzelin J.M.
Published: November 2013

Feeding behavior of Melanaphis sacchari Zehntner (Hemiptera: Aphididae) was studied on sugarcane, Saccharum spp. (Poaceae), cultivars HoCP 91‐555 (resistant), LCP 85‐384 (moderately resistant), and L 97‐128 (susceptible) using the electrical penetration graph (EPG) technique. Constitutive concentrations of total phenolics and available carbohydrates, water potential at the whole‐leaf tissue level, and free amino acids (FAAs) in phloem sap extracts, and in honeydew produced by aphids fed on L 97‐128 and HoCP 91‐555 were determined. Cultivar did not influence time for M. sacchari to access phloem sieve elements. Total time in sieve elements was ca. two‐fold greater on L 97‐128 than on HoCP 91‐555, whereas it did not differ from LCP 85‐384 in either cultivar. The mean duration of individual events associated with phloem sap ingestion was ca. 50% shorter on both HoCP 91‐555 and LCP 85‐384 than on L 97‐128. Although cultivar effects were not detected for levels of total phenolics, available carbohydrates, and water potential, two free essential amino acids, histidine and arginine, were absent from phloem sap in HoCP 91‐555. Two free essential amino acids, leucine and isoleucine, and two free non‐essential amino acids, tyrosine and proline, were absent from honeydew of aphids fed on HoCP 91‐555. These results suggest that despite apparent biosynthesis of some FAAs, the absence of important FAAs in the phloem sap of HoCP 91‐555 and the inability of M. sacchari and its endosymbionts (e.g., Buchnera) to derive specific free essential and non‐essential amino acids from other ingested molecules, possibly along with other unidentified factors, underlie the pest's decreased phloem sap ingestion and consequently reduced growth potential on HoCP 91‐555.
A multidimensional typology of riverbank habitats explains the distribution of European grayling (Thymallus thymallus L.) fry in a temperate river
Authors: Cattanéo Franck , Grimardias David , Carayon Marie , Persat Henri , Bardonnet Agnès
Published: November 2013

For species at risk, rehabilitation of riverbank habitats may be a promising way to sustain abundance of early‐life stages, provided that fish—habitat relationships are significant and the scale at which they are described is relevant to both fish ecology and management purposes. Here, habitat use of the threatened European grayling (Thymallus thymallus) fry was analysed in an alluvial French‐Swiss border river, the Allondon. Based on five descriptive variables, a practical typology of available bank habitats was first defined to categorise ecological conditions into five easily distinguishable habitat types (HTs). These represent marginal patches of multivariate homogeneous habitat from a few to tens of square metres [median area = 8 m−2; range (10%–90%) = 1.9–32.6 m−2]. Comparing the habitat used by fry to those available revealed a clear selection for two of the five HTs, that is, gravel bar shorelines (HT4) and depositional beaches along pool margins (HT3). Because of their multidimensional nature and larger spatial scale, HTs did not strictly reflect an up‐scaling of univariate selection patterns at the microhabitat scale. Results emphasised that the preservation of the alluvial dynamics of the river and bank patchiness are basic to European grayling, and suggested that the patch scale may represent a good compromise between ecological relevancy and practical management needs. The herein developed typological approach may be transferred to other rivers and help conserve European grayling populations by enhancing fry habitat suitability.
Reasons for cannabis use among youths at ultra high risk for psychosis
Authors: Gill Kelly E. , Poe Lucy , Azimov Neyra , Ben‐David Shelly , Vadhan Nehal P. , Girgis Ragy , Moore Holly , Cressman Victoria , Corcoran Cheryl M.
Published: November 2013

Aim

Cannabis use is prevalent in schizophrenia and its risk states, despite its association with anxiety and positive symptoms. While schizophrenia patients report using cannabis for mood enhancement and social motives, it is not known what motivates clinical high risk (CHR) patients to use cannabis.

Methods

Among 102 CHR patients, 24 (23%) endorsed cannabis use, and were queried as to reasons for use, using a scale previously administered in schizophrenia patients. We hypothesized a primary motivation for mood enhancement related to anhedonia. We evaluated the ‘self‐medication’ hypothesis by examining if motivation for symptom relief was associated with concurrent severity of symptoms.

Results

The rank order of reasons for use in CHR patients was similar to that previously reported by schizophrenia patients, with mood enhancement and social motives as primary reasons for use, and the motivation to use cannabis for symptom relief comparatively less common. Motivation for mood enhancement had a trend association with anhedonia. Motivation for symptom relief was entirely unrelated to concurrent severity of positive and anxiety symptoms.

Conclusion

As in schizophrenia, CHR patients primarily use cannabis for mood enhancement, especially in the context of decreased motivation to seek pleasure otherwise. Negative symptoms may drive cannabis use in schizophrenia and its risk states, which may exacerbate positive symptoms. By contrast, CHR patients do not report using cannabis to ‘self‐medicate’ emergent positive symptoms. The understanding of motives for cannabis use among CHR patients may be informative for treatments aimed at reducing use, such as motivational interviewing.
A kinetic model of catabolic adaptation and protein reprofiling in Saccharomyces cerevisiae during temperature shifts
Authors: Mensonides Femke I. C. , Brul Stanley , Hellingwerf Klaas J. , Bakker Barbara M. , Teixeira de Mattos M. Joost
Published: November 2013

In this article, we aim to find an explanation for the surprisingly thin line, with regard to temperature, between cell growth, growth arrest and ultimately loss of cell viability. To this end, we used an integrative approach including both experimental and modelling work. We measured the short‐ and long‐term effects of increases in growth temperature from 28 °C to 37, 39, 41, 42 or 43 °C on the central metabolism of Saccharomyces cerevisiae. Based on the experimental data, we developed a kinetic mathematical model that describes the metabolic and energetic changes in growing bakers' yeast when exposed to a specific temperature upshift. The model includes the temperature dependence of core energy‐conserving pathways, trehalose synthesis, protein synthesis and proteolysis. Because our model focuses on protein synthesis and degradation, the net result of which is important in determining the cell's capacity to grow, the model includes growth, i.e. glucose is consumed and biomass and adenosine nucleotide cofactors are produced. The model reproduces both the observed initial metabolic response and the subsequent relaxation into a new steady‐state, compatible with the new ambient temperature. In addition, it shows that the energy consumption for proteome reprofiling may be a major determinant of heat‐induced growth arrest and subsequent recovery or cell death.
High Hemoglobin A1c levels and glycemic variability increase risk of severe hypoglycemia in diabetic hemodialysis patients
Authors: Williams Mark E. , Garg Rajesh , Wang Weiling , Lacson Ronilda , Maddux Franklin , Lacson Eduardo
Published: November 2013

While hyperglycemia is central to the pathogenesis and management of diabetes mellitus, hypoglycemia and glucose variability also contribute to outcomes. We previously reported on the relationship of glycemic control to outcomes in a large population of diabetic end‐stage renal disease (ESRD) patients. Recognizing that ESRD is a risk factor for severe hypoglycemia, we have now analyzed the association between glycosylated hemoglobin A1c (HgbA1c) levels and glycemic variability in those with hypoglycemia. This is a retrospective study of patients with diabetes enrolled in a large hemodialysis program. Hypoglycemia was identified from hospital discharge diagnostic codes. Glycemic variability was assessed by the standard deviation of HgbA1c and glucose levels over time. Hypoglycemia as a discharge diagnosis was documented in 4.1% of patients. Higher baseline HgbA1c was associated with greater risk for hypoglycemia hospitalization, a finding confirmed by time‐lagged HgbA1c levels drawn a quarter earlier. Higher baseline HgbA1c categories were also associated with greater variability in HgbA1c levels during the analysis period. Similarly, greater glucose variability was associated with higher mean glucose levels by trend analysis. High, not low, HgbA1c levels are associated with greater risk of severe hypoglycemia, which may derive from glucose variability in the setting of treatment for hyperglycemia. High HgbA1c and glycemic variability are associated with increased risk of hypoglycemia in individuals with diabetes and ESRD.
Patient mood flux on‐ and off‐hemodialysis
Authors: Leshem Micah , Sliman Wisam , Taweel Souzan , Shamshoum Rana , Armaly Zaher
Published: November 2013

Mood in hemodialysis patients is most often evaluated off‐dialysis, possibly underestimating mood during dialysis. We compared mood in patients on‐ and off‐dialysis using the Positive and Negative Affect Schedule for 6 consecutive days. Initially, scores are normal, but subsequently positive affect falls below, and negative affect increases above, off‐dialysis values, suggesting increasing depression and anxiety, particularly in women. Quality‐of‐life questions confirm the effects of the dialysis session on mood. Prevalence and severity of depression evaluated off‐dialysis, or once only, may be underestimated, especially in women, because hemodialysis patients undergo mood swings centering on the dialysis session. Focusing insight on the dialysis session could improve coping among patients and caretakers.
Thrombosed hemodialysis access as an unusual source of emboli in the upper extremity of a kidney transplant recipient
Authors: Kim Mi‐Hyeong , Hwang Jeong Kye , Chun Ho Jong , Moon In Sung , Kim Ji Il
Published: November 2013

Arteriovenous fistula (AVF) is no longer used in kidney transplant recipients. However, there is no consensus regarding whether or not to ligate a well‐functioning AVF after successful kidney transplantation, particularly in patients with well and stably functioning kidney transplants. Most AVFs without complications are left in situ and more than one‐third of native AVFs close spontaneously. The currently accepted policy toward thrombosed AVFs is retention within the patient's extremity without treatment. These thrombosed AVFs seldom cause serious problems. However, when combined with aneurysmal dilatation of the proximal vein adjacent to the arterial anastomotic area, the AVF could act as the source of distal arterial emboli. This is very similar clinical scenario to that observed in embolization from a peripheral arterial aneurysm. Here we describe a case report of upper extremity ischemia following massage of a thrombosed aneurysmal AVF. The patient was successfully treated with a combination of catheter‐directed thromboaspiration, thrombolysis, and surgical repair of the thrombosed AVF. To the best of our knowledge, this is the first report of upper extremity embolism after massage of a thrombosed aneurysmal AVF involving this combined treatment.
Influence of carbohydrates on self‐association of mung bean protein hydrolysate in the presence of amphiphilic asiatic acid
Authors: Wongekalak La‐Ongdao , Hongsprabhas Parichat
Published: November 2013

This study investigated the influence of surface‐inactive carbohydrates on association characteristics of amphiphilic mung bean protein hydrolysate (MPH) and asiatic acid (AA) in aqueous suspension (11.72–11.94% total solids). The carbohydrates investigated were trehalose, maltodextrin, mixed trehalose–maltodextrin and mixed maltodextrin–starch. The presence of low‐molecular‐weight carbohydrates enhanced micellisation of AA to form micrometre‐sized particles due to depletion flocculation. Nonetheless, the presence of starch retained the submicrometre size of AA. In contrast, the presence of starch enhanced self‐association of MPH via segregative phase separation. However, the mixed suspensions containing MPH, AA and carbohydrate in a ratio of 1:0–0.072:2.34, respectively, retained particle sizes of around 300 nm regardless of the carbohydrate used. It was found that the MPH–AA co‐aggregates were stable against the osmotic effect of carbohydrates. The results suggest that carbohydrates regulated the aggregate size and surface hydrophobic region of MPH and MPH–AA by controlling surface‐induced aggregation.