bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial and temporal aridity gradients provide poor proxies for plant–plant interactions under climate change: a large‐scale experiment
Authors: Metz Johannes , Tielbörger Katja 
Published: November 2015

Summary

Plant–plant interactions may critically modify the impact of climate change on plant communities. However, the magnitude and even direction of potential future interactions remains highly debated, especially for water‐limited ecosystems. Predictions range from increasing facilitation to increasing competition with future aridification.

The different methodologies used for assessing plant–plant interactions under changing environmental conditions may affect the outcome but they are not equally represented in the literature. Mechanistic experimental manipulations are rare compared with correlative approaches that infer future patterns from current observations along spatial climatic gradients.

Here, we utilize a unique climatic gradient in combination with a large‐scale, long‐term experiment to test whether predictions about plant–plant interactions yield similar results when using experimental manipulations, spatial gradients or temporal variation. We assessed shrub–annual interactions in three different sites along a natural rainfall gradient (spatial) during 9 years of varying rainfall (temporal) and 8 years of dry and wet manipulations of ambient rainfall (experimental) that closely mimicked regional climate scenarios.

The results were fundamentally different among all three approaches. Experimental water manipulations hardly altered shrub effects on annual plant communities for the assessed fitness parameters biomass and survival. Along the spatial gradient, shrub effects shifted from clearly negative to mildly facilitative towards drier sites, whereas temporal variation showed the opposite trend: more negative shrub effects in drier years.

Based on our experimental approach, we conclude that shrub–annual interaction will remain similar under climate change. In contrast, the commonly applied space‐for‐time approach based on spatial gradients would have suggested increasing facilitative effects with climate change. We discuss potential mechanisms governing the differences among the three approaches.

Our study highlights the critical importance of long‐term experimental manipulations for evaluating climate change impacts. Correlative approaches, for example along spatial or temporal gradients, may be misleading and overestimate the response of plant–plant interactions to climate change.
Phase‐dependent climate–predator interactions explain three decades of variation in neonatal caribou survival
Authors: Bastille‐Rousseau Guillaume , Schaefer James A. , Lewis Keith P. , Mumma Matthew A. , Ellington E. Hance , Rayl Nathaniel D. , Mahoney Shane P. , Pouliot Darren , Murray Dennis L. 
Published: November 2015

Summary

Climate can have direct and indirect effects on population dynamics via changes in resource competition or predation risk, but this influence may be modulated by density‐ or phase‐dependent processes. We hypothesized that for ungulates, climatic conditions close to parturition have a greater influence on the predation risk of neonates during population declines, when females are already under nutritional stress triggered by food limitation.

We examined the presence of phase‐dependent climate–predator (PDCP) interactions on neonatal ungulate survival by comparing spatial and temporal fluctuations in climatic conditions, cause‐specific mortality and per capita resource limitation. We determined cause‐specific fates of 1384 caribou (Rangifer tarandus) from 10 herds in Newfoundland, spanning more than 30 years during periods of numerical increase and decline, while exposed to predation from black bears (Ursus americanus) and coyotes (Canis latrans).

We conducted Cox proportional hazards analysis for competing risks, fit as a function of weather metrics, to assess pre‐ and post‐partum climatic influences on survival on herds in population increase and decline phases. We used cumulative incidence functions to compare temporal changes in risk from predators.

Our results support our main hypothesis; when caribou populations increased, weather conditions preceding calving were the main determinants of cause‐specific mortality, but when populations declined, weather conditions during calving also influenced predator‐driven mortality. Cause‐specific analysis showed that weather conditions can differentially affect predation risk between black bears and coyotes with specific variables increasing the risk from one species and decreasing the risk from the other.

For caribou, nutritional stress appears to increase predation risk on neonates, an interaction which is exacerbated by susceptibility to climatic events. These findings support the PDCP interactions framework, where maternal body condition influences susceptibility to climate‐related events and, subsequently, risk from predation.
Ecologically diverse and distinct neighbourhoods trigger persistent phenotypic consequences, and amine metabolic profiling detects them
Authors: Hennion Françoise , Litrico Isabelle , Bartish Igor V. , Weigelt Alexandra , Bouchereau Alain , Prinzing Andreas 
Published: November 2015

Summary

Global change triggers rapid alterations in the composition and diversity of plant communities which may change ecosystem functioning. Do changes in community diversity also change traits persistently, that is does coexistence with numerous or functionally or phylogenetically distinct species trigger, in a given focal species, trait shifts that persist?

We studied the grass Dactylis glomerata. Dactylis was grown in experimental plots with different species compositions for 5 years, sampled, cloned and grown in a common garden. We studied amines, regulators integrating growth responses of organisms to their environment.

We found that the mean levels and variances of most amines depended on the diversity of the source community, notably the species richness and the phylogenetic and functional distinctness from Dactylis, unbiased by species identity or biomass shifts.

Synthesis. Our results suggest that different levels of ambient diversity can, within a few years, select for different genotypes which have different compositions of growth regulators. Our study also suggests that a plant species can evolve in response to the diversity or distinctness of the surrounding plant community. Evolutionary changes of plant phenotypes might mediate an impact of past biological diversity on present ecosystem functioning.
Agricultural land usage transforms nitrifier population ecology
Authors: Bertagnolli Anthony D. , McCalmont Dylan , Meinhardt Kelley A. , Fransen Steven C. , Strand Stuart , Brown Sally , Stahl David A. 
Published: November 2015

SummaryApplication of nitrogen fertilizer has altered terrestrial ecosystems. Ammonia is nitrified by ammonia and nitrite‐oxidizing microorganisms, converting ammonia to highly mobile nitrate, contributing to the loss of nitrogen, soil nutrients and production of detrimental nitrogen oxides. Mitigating these costs is of critical importance to a growing bioenergy industry. To resolve the impact of management on nitrifying populations, amplicon sequencing of markers associated with ammonia and nitrite‐oxidizing taxa (ammonia monooxygenase‐amoA, nitrite oxidoreductase‐nxrB, respectively) was conducted from long‐term managed and nearby native soils in Eastern Washington, USA. Native nitrifier population structure was altered profoundly by management. The native ammonia‐oxidizing archaeal community (comprised primarily by Nitrososphaera sister subclusters 1.1 and 2) was displaced by populations of Nitrosopumilus, Nitrosotalea and different assemblages of Nitrososphaera (subcluster 1.1, and unassociated lineages of Nitrososphaera). A displacement of ammonia‐oxidizing bacterial taxa was associated with management, with native groups of Nitrosospira (cluster 2 related, cluster 3A.2) displaced by Nitrosospira clusters 8B and 3A.1. A shift in nitrite‐oxidizing bacteria (NOB) was correlated with management, but distribution patterns could not be linked exclusively to management. Dominant nxrB sequences displayed only distant relationships to other NOB isolates and environmental clones.
Pattern of hepatocellular carcinoma recurrence following living donor liver transplantation
Authors: Zakaria Hazem M. , Shoreem Hany A. , Aziz Amr A. , Abou El‐Ella Khaled A. , Ibrahim Tarek M. 
Published: November 2015

AimLiving donor liver transplantation (LDLT) is a promising treatment option for patients with hepatocellular carcinoma (HCC), but tumour recurrence can affect long‐term survival. The aim of the present study was to identify the pattern of HCC recurrence after LDLT for early detection and management.Patients and MethodsFrom April 2003 to October 2014, the record of 60 patients who underwent LDLT for HCC at the National Liver Institute, Menoufia University, Egypt, were retrospectively reviewed. The clinicopathological data were analysed to determine factors associated with HCC recurrence and outcome.ResultsSeven patients (11.7 per cent) had HCC recurrence after LDLT. Pretransplant α‐fetoprotein (AFP) > 1000 ng/mL, tumour grade and microvascular invasion were the incriminated risk factors for recurrence. Three patients (42.8 per cent) had intrahepatic and extrahepatic recurrence (lung and bone), two patients (28.6 per cent) had only extrahepatic recurrence in bones and two patients (28.6 per cent) had only intrahepatic recurrence. Management was as follows: two patients (28.6 per cent) had surgical excision of intrahepatic recurrence and extrahepatic metastasis, two patients (28.6 per cent) underwent radiotherapy for bone metastasis, one patient (14.2 per cent) underwent intraoperative radiofrequency ablation for liver recurrence and two patients (28.6 per cent) received sorafenib as medical treatment. The mean time of recurrence was 19.7 months, and mean survival was 29 months.ConclusionThe majority of HCC recurrences after LDLT are extrahepatic and occur mainly in the first 2 years; strict follow up is required during this period. A high level of pretransplant serum AFP and microvascular invasion are risk factors for tumour recurrence and should be taken into account when selecting candidates for LDLT.
Lesbian, gay, bisexual and transgender people's attitudes to end‐of‐life decision‐making and advance care planning
Authors: Hughes Mark , Cartwright Colleen 
Published: November 2015

AimTo examine lesbian, gay, bisexual and transgender (LGBT) people's attitudes to advance care planning (ACP) options and alternative decision‐making at the end of life.MethodThree hundred and five LGBT people completed an online or paper‐based questionnaire, comprising fixed‐choice questions and open‐ended questions.ResultsMost respondents, particularly those identifying as female or transgender, preferred a partner to be their alternative decision‐maker at the end of life should the need arise. Fifty‐two per cent of respondents had spoken to this person about their wishes. Regarding legal options enabling end‐of‐life decision‐making, 29% had an enduring power of attorney, 18% an enduring guardian and 12% an advance care directive.ConclusionDespite the significance of ACP for promoting the rights of LGBT people at the end of life, the take‐up of these options was nearly as low as for the general population. The potential for targeted strategies to increase the take‐up of ACP is identified.
Endoscopic modalities for upper gastrointestinal leaks, fistulae and perforations
Authors: Talbot Michael , Yee Gary , Saxena Payal 
Published: November 2015

AbstractBackgroundEndotherapy techniques are a recent addition to the suite of non‐surgical and minimally invasive strategies to manage patients with perforations, leaks and fistulae. The emergency nature of these conditions and the heterogeneity of pathologies encountered create difficulties when trying to select appropriate tools in these complex situations. The purpose of this article is to review experience at a tertiary academic centre, describe the various endoscopic tools available and the situations where they can be considered for use.MethodsSingle‐centre series and review of the published literature.ResultsOf 64 patients, 57 were successfully treated using endoscopic therapy, with surgery used only to provide drainage and suture fully covered metal stents in place to prevent migration.DiscussionSelection of an appropriate endotherapy or stent for a patient with an oesophago‐gastric perforation or fistula requires an understanding of the anatomy and physiology underlying the patient's presentation and an understanding of the strengths and weaknesses of the available methods. Standard surgical principles of drainage, avoidance of distal obstruction and nutrition remain central to successful outcomes. A combination of surgical and endoscopic treatments may reduce the number of required treatments and can provide the ability to anchor fully covered stents to prevent them from migrating.
Colorectal multidisciplinary meeting audit to determine patient benefit
Authors: Fernando Chris , Frizelle Frank , Wakeman Chris , Frampton Chris , Robinson Bridget 
Published: November 2015

AbstractBackgroundNew Zealand tumour standards require discussion of all cases of colorectal cancer in a multidisciplinary meeting (MDM), but supporting evidence is lacking. The aim was to determine which patients benefit from MDM discussion.MethodsA retrospective and prospective audit was undertaken of all patients discussed in the Christchurch Hospital colorectal MDM over 12 months to November 2014, who were compared with contemporaneous patients not discussed and identified through Hospital discharge codes.ResultsIn total, 641 patients were identified, with 459 (70%) discussed in the MDM, on average 7 years younger than not discussed. The proportion discussed by location was 39.2% colon, 63% rectosigmoid, 98% rectal, 96.6% anal. Discussed patients were more likely to have magnetic resonance imaging (68% cf 9.3%), fluorodeoxyglucose positron emission tomography scan (18% versus 2%) and chest computerized tomography scan (50% versus 26%). For colon cancer, American Joint Committee on Cancer (AJCC) stage I and II, 91% of 68 non‐discussed patients went straight to surgery compared with 48% of 27 discussed in the MDM; for AJCC stage III uptake of adjuvant chemotherapy was the same whether discussed or not. An R0 resection was achieved for 91% of discussed patients, and 96% of not discussed. A clear referrer's plan, prospectively recorded in 94 patients, was changed after the MDM in 23%. Clinical staging was changed in 20 patients (4%), none with colon cancers.ConclusionsDiscussion in the MDM influenced management, but was unlikely to change management for AJCC stage I/II colon cancer, who could be spared mandatory review in the MDM and be discussed selectively as treating clinicians decide.
Computational Fluid Dynamics‐Based Design Optimization Method for Archimedes Screw Blood Pumps
Authors: Yu Hai , Janiga Gábor , Thévenin Dominique 
Published: November 2015

AbstractAn optimization method suitable for improving the performance of Archimedes screw axial rotary blood pumps is described in the present article. In order to achieve a more robust design and to save computational resources, this method combines the advantages of the established pump design theory with modern computer‐aided, computational fluid dynamics (CFD)‐based design optimization (CFD‐O) relying on evolutionary algorithms and computational fluid dynamics. The main purposes of this project are to: (i) integrate pump design theory within the already existing CFD‐based optimization; (ii) demonstrate that the resulting procedure is suitable for optimizing an Archimedes screw blood pump in terms of efficiency. Results obtained in this study demonstrate that the developed tool is able to meet both objectives. Finally, the resulting level of hemolysis can be numerically assessed for the optimal design, as hemolysis is an issue of overwhelming importance for blood pumps.
A New Absorbable Synthetic Substitute With Biomimetic Design for Dural Tissue Repair
Authors: Shi Zhidong , Xu Tao , Yuan Yuyu , Deng Kunxue , Liu Man , Ke Yiquan , Luo Chengyi , Yuan Tun , Ayyad Ali 
Published: November 2015

AbstractDural repair products are evolving from animal tissue–derived materials to synthetic materials as well as from inert to absorbable features; most of them lack functional and structural characteristics compared with the natural dura mater. In the present study, we evaluated the properties and tissue repair performance of a new dural repair product with biomimetic design. The biomimetic patch exhibits unique three‐dimensional nonwoven microfiber structure with good mechanical strength and biocompatibility. The animal study showed that the biomimetic patch and commercially synthetic material group presented new subdural regeneration at 90 days, with low level inflammatory response and minimal to no adhesion formation detected at each stage. In the biological material group, no new subdural regeneration was observed and severe adhesion between the implant and the cortex occurred at each stage. In clinical case study, there was no cerebrospinal fluid leakage, and all the postoperation observations were normal. The biomimetic structure and proper rate of degradation of the new absorbable dura substitute can guide the meaningful reconstruction of the dura mater, which may provide a novel approach for dural defect repair.
Psychological predictors of pain severity, pain interference, depression, and anxiety in rheumatoid arthritis patients with chronic pain
Authors: Ryan Seamus , McGuire Brian 
Published: November 2015

ObjectivesRheumatoid arthritis is a chronic and progressive autoimmune disorder with symptoms sometimes including chronic pain and depression. The current study aimed to explore some of the psychological variables which predict both pain‐related outcomes (pain severity and pain interference) and psychological outcomes (depression and anxiety) amongst patients with rheumatoid arthritis experiencing chronic pain. In particular, this study aimed to establish whether either self‐concealment, or the satisfaction of basic psychological needs (autonomy, relatedness, and competence), could explain a significant portion of the variance in pain outcomes and psychological outcomes amongst this patient group.Design/MethodsOnline questionnaires were completed by 317 rheumatoid arthritis patients with chronic pain, providing data across a number of predictor and outcome variables.ResultsHierarchical multiple linear regressions indicated that the predictive models for each of the four outcome variables were significant, and had good levels of fit with the data. In terms of individual predictor variables, higher relatedness significantly predicted lower depression, and higher autonomy significantly predicted lower anxiety.ConclusionsThe model generated by this study may identify factors to be targeted by future interventions with the goal of reducing depression and anxiety amongst patients with rheumatoid arthritis experiencing chronic pain. The findings of this study have shown that the autonomy and the relatedness of patients with rheumatoid arthritis play important roles in promoting psychological well‐being. Targeted interventions could help to enhance the lives of patients despite the presence of chronic pain.
Statement of contribution

What is already known about the subject?

Amongst a sample of chronic pain patients who primarily had a diagnosis of fibromyalgia, it was found that higher levels of self‐concealment were associated with higher self‐reported pain levels and reduced well‐being (as measured by anxiety/depression), and these associations were mediated by patients’ needs for autonomy not being met (Uysal & Lu, Health Psychology, 2011, 30, 606).

What does this study add?

For the first time amongst a rheumatoid arthritis population experiencing chronic pain, we found that higher levels of relatedness significantly predicted lower depression.

For the first time amongst the same population, we found that higher levels of autonomy significantly predicted lower anxiety.
Multi‐set factor analysis by means of Parafac2
Authors: Stegeman Alwin , Lam Tam T. T. 
Published: November 2015

We consider multi‐set data consisting of observations, k = 1,…, K (e.g., subject scores), on J variables in K different samples. We introduce a factor model for the J × J covariance matrices , k = 1,…, K, where the common part is modelled by Parafac2 and the unique variances , k = 1,…, K, are diagonal. The Parafac2 model implies a common loadings matrix that is rescaled for each k, and a common factor correlation matrix. We estimate the unique variances by minimum rank factor analysis on for each k. The factors can be chosen orthogonal or oblique. We present a novel algorithm to estimate the Parafac2 part and demonstrate its performance in a simulation study. Also, we fit our model to a data set in the literature. Our model is easy to estimate and interpret. The unique variances, the factor correlation matrix and the communalities are guaranteed to be proper, and a percentage of explained common variance can be computed for each k. Also, the Parafac2 part is rotationally unique under mild conditions.
2‐Hydoxyglutarate: D/Riving Pathology in gLiomaS
Authors: Wahl Daniel R. , Venneti Sriram 
Published: November 2015

AbstractCommon pathways and mechanisms can be found in both cancers and inborn errors of metabolism. 2‐Hydroxyglutarate (2‐HG) acidurias and isocitrate dehydrogenase (IDH) 1/2 mutant tumors are examples of this phenomenon. 2‐HG can exist in two chiral forms, D(R)‐2‐HG and L(S)‐2‐HG, which are elevated in D‐ and L‐acidurias, respectively. D‐2‐HG was subsequently discovered to be synthesized in IDH 1/2 mutant tumors including ∼70% of intermediate‐grade gliomas and secondary glioblastomas (GBM). Recent studies have revealed that L‐2‐HG is generated in hypoxia in IDH wild‐type tumors. Both 2‐HG enantiomers have similar structures as α‐ketoglutarate (α‐KG) and can competitively inhibit α‐KG‐dependent enzymes. This inhibition modulates numerous cellular processes, including histone and DNA methylation, and can ultimately impact oncogenesis. D‐2‐HG can be detected in vivo in glioma patients and animal models using advanced imaging modalities. Finally, pharmacologic inhibitors of mutant IDH 1/2 attenuate the production of D‐2‐HG and show great promise as therapeutic agents.