bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristic features of pulmonary function test, CT volume analysis and MR perfusion imaging in COPD patients with different HRCT phenotypes
Authors: Fan Li , Xia Yi , Guan Yu , Zhang Tie‐feng , Liu Shi‐yuan
Published: May 2013

Introduction

Computed tomography (CT) and magnetic resonance imaging (MRI) can provide detailed anatomic structures and quantitative function information for chronic obstructive pulmonary disease (COPD).

Objectives

To prospectively clarify characteristics of pulmonary function test (PFT), CT volume parameters and magnetic resonance (MR) perfusion imaging in COPD patients with different high‐resolution computed tomography (HRCT) phenotypes.

Methods

 

Sixty‐two patients performed PFT, CT and MR perfusion imaging. COPD was classified into three phenotypes according to HRCT quantitative findings: A, E and M phenotype. Total lung volume (TLV), total emphysema volume (TEV) and emphysema index (EI) were quantitated by HRCT. In cases of perfusion defects (PDs), the shape and size were evaluated. The contrast between the normal lung and PDs was quantified by calculating their signal intensity ratio (RSI = SIPD/SInormal). The correlation was performed between PFT, CT and MR perfusion.

Results

There were 42 A phenotype, 9 E phenotype and 11 M phenotype. There was significant difference in forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) between A and M phenotype (P < 0.05). TEV and EI of A phenotype (0.4 ± 0.4 L and 8.0% ± 4.3%) were lower than those of E (1.0 ± 0.3 L and 18.6% ± 3.2%) or M phenotype (0.9 ± 0.2 L and 17.5% ± 1.7%). MR perfusion images showed circumscribed or diffuse patchy PDs. RSI of A phenotype was higher than that of E phenotype (20.3% ± 8.5% vs 11.8% ± 5.4%; P = 0.006). TEV and EI were moderate negatively correlated with diffusion function parameters. RSI was strongly correlated with FEV1% (A) and FEV1/FVC (M). FEV1/FVC was strongly correlated with TEV or EI (E).

Conclusion

There were different features and correlations between PFT, CT volume and MR perfusion in different phenotype, indicating each phenotype may have novel imaging method guiding clinical management.
Epidemiology and distribution of interstitial lung diseases in Turkey
Authors: Musellim Benan , Okumus Gulfer , Uzaslan Esra , Akgün Metin , Cetinkaya Erdogan , Turan Onur , Akkoclu Atila , Hazar Armagan , Kokturk Nurdan , Calisir Haluk Celalettin ,   Turkish Interstitial Lung Diseases Group
Published: May 2013

Introduction

There is very few data on the epidemiological features of interstitial lung diseases (ILD) in the literature. These studies on this subject suffer from limited number of patients.

Objective

The goal of this study was to evaluate the epidemiological features of ILD in Turkey.

Methods

Fifty‐four investigators, 31 centres in 19 cities from six regions of Turkey, participated in the study. Two thousand two hundred forty‐five newly diagnosed patients (51.8% females), led by Turkish Thoracic Society Clinical Problems Study Group, enrolled in this prospective study.

Results

The mean age was 51.8 ± 16.7 years. The mean age among males was 50.5 ± 18.6 years and 53.0 ± 14.6 years among females (P < 0.001). 23.8% of the cases had ILD with known causes, while 39.4% were in granulomatous group, 23.7% were idiopathic, and 4.4% were in the unclassified group. Overall, histopathologically confirmed diagnosis rate was 40.4%. Sarcoidosis was the most common disease (37%), whereas cases with idiopathic pulmonary fibrosis (IPF) constituted 19,9% of patients. 53% of the sarcoidosis patients were females, and the ratio reaches to 75% under 50 years of age (for this group, IPF ratio is %3). In contrast, sarcoidosis and IPF ratios were equal in males (25%). Sarcoidosis was 8% in men over 50, while IPF was %45.

Conclusion

The overall incidence of ILD in Turkey was computed to be 25.8/100 000.
Lung transplant outcomes in cystic fibrosis patients with pre‐operative Mycobacterium abscessus respiratory infections
Authors: Lobo Leonard J. , Chang Lydia C. , Esther Charles R. , Gilligan Peter H. , Tulu Zeynep , Noone Peadar G.
Published: May 2013

Background

Mycobacterium abscessus in cystic fibrosis (CF) patients is considered a contraindication to lung transplantation. We examine the post‐transplant outcomes of CF patients with M. abscessus pre‐transplant.

Methods

CF patients transplanted at the University of North Carolina from 1992 to 2012 were retrospectively examined. Patients with at least one respiratory sample positive for M. abscessus prior to transplantation were included. Data collected included age, FEV1, body mass index (BMI), systemic steroid use, diabetes mellitus, ventilatory assistance, co‐existent CF pathogens, imaging, post‐transplant complications, and survival.

Results (n = 13)

At transplant, mean age was 24.6 yr, mean BMI was 18.1 kg/m2, six had 3+ positive smears for M. abscessus, and three were ventilator dependent. All met American Thoracic Society microbiological criteria for disease pre‐transplant. Three patients developed M. abscessus‐related complications, with clearance of the organism following treatment. Survival post‐transplant shows 77% alive at one yr, 64% at three yr, and 50% at five yr; none died of M. abscessus. The survival data showed no statistically significant difference (p = 0.8) compared with a contemporaneously transplanted population of CF patients without M. abscessus (n = 154).

Conclusion

Lung transplantation, with favorable survival, is possible in CF patients with M. abscessus. Even if M. abscessus recurs, local control and clearance is possible.
Tacrolimus plus mycophenolate mofetil vs. cyclosporine plus everolimus in deceased donor kidney transplant recipients: three‐yr results of a single‐center prospective clinical trial
Authors: Favi Evaldo , Spagnoletti Gionata , Salerno Maria P. , Pedroso José A. , Romagnoli Jacopo , Citterio Franco
Published: May 2013

We compared in kidney transplantation two immunosuppressive regimens: tacrolimus plus mycophenolate mofetil (MMF) (TAC) and everolimus plus low‐dose cyclosporine (EVE). Sixty consecutive patients received TAC (30 patients) or EVE (30 patients) as immunosuppressive regimen; all subjects also received induction with basiliximab and corticosteroids. After three‐yr follow‐up, no difference was found in patient and graft survival (PTS: TAC: 97% vs. EVE: 100%; GS: TAC: 93% vs. EVE: 93%). The incidence of acute rejection was higher in the EVE group but the difference was not statistically significant (17% vs. 23%, p = ns). Patients in EVE showed higher serum cholesterol (205 ± 41 vs. 235 ± 41 mg/dL, p = 0.0012) and lower hemoglobin concentration (13.6 ± 1.4 vs. 12.4 ± 1.9, p = 0.01). Renal function was not significantly different in the two groups (3 Y creatinine: TAC 1.4 ± 0.8 vs. EVE 1.6 ± 0.8 mg/dL, p = ns). Treatment discontinuation was higher in the EVE group (TAC 17 vs. EVE 36%, p = ns). Our data show that in the middle‐term follow‐up, an immunosuppressive regimen with tacrolimus plus MMF has a similar efficacy and safety profile in comparison with the combination of low‐exposure cyclosporine plus everolimus. Further follow up could evidence the benefits related to the anti‐proliferative effects of everolimus.
Does Aid Unpredictability Weaken Governance? Evidence from Developing Countries
Authors: Kangoye Thierry
Published: May 2013

This paper examines the effects of aid on governance from a different perspective by asserting that aid unpredictability can potentially increase corruption in recipient countries by providing incentives to risk‐averse and corrupt political leaders to engage in rent‐seeking activities. Analyses of data from 80 developing countries over the period 1984–2004 offer evidence that higher aid unpredictability is associated with more corruption as measured by a synthetic index. We also find further evidence that this latter impact is more severe in countries with weak initial institutional conditions. These findings are a supplementary advocacy for the need for better management and better predictability of aid flow in developing countries.
Trade Opening, Fiscal Reforms, Poverty, and Inequality: A CGE Analysis for Bangladesh
Authors: Nahar Bodrun , Siriwardana Mahinda
Published: May 2013

We assess the short‐ and long‐run impacts of tariff reform policies on Bangladeshi households' poverty and income distribution by developing an 86‐sector, four‐factor, and nine‐household‐group computable general equilibrium (CGE) model. The main findings are that the complete removal of tariffs leads to a decrease in overall poverty with rich household groups in a relatively better position. In the short run poverty incidence increases for rural landless, urban illiterate, and low‐educated household groups whereas rural large farmer and urban medium household groups enjoy improvements in all poverty indicators. In terms of income distribution, trade liberalization enhances inequality slightly, but there is a tendency towards more equitable distribution in the long run. The choice of a fiscal compensatory mechanism with consumption tax is likely to play a negative role in terms of poverty and inequality in the short run; however, interestingly, the results are pro‐poor in the long run.
Technological Change, Job Risk, and Wage Premium: Evidence from Taiwan
Authors: Liu Jin‐Long , Huang Chia‐Hui , Yang Chih‐Hai
Published: May 2013

The paper reports the results of analyzing the effects of technological change and job risk on wage premiums in Taiwan. Using unique individual data combined with industry‐level indices of technological change and fatality rates across industries, the empirical results show that, overall, industries characterized by a higher rate of technological change or fatality pay a higher wage. However, these positive correlations are attributed to the sorting effect in which workers with some specific features choose to find jobs in industries with rapid technological change and higher job risk. Furthermore, this paper reports a positive relationship between education and wages after controlling for individual heterogeneity, showing the existence of education premium in Taiwan.
Beliefs, Economic Volatility, and Redistributive Preferences Across Developing Countries
Authors: Duman Anil
Published: May 2013

Beliefs about social competition affect redistributive demands and the responsibility assigned to government regarding public provisions. Given the strong link between beliefs and the extent of support for social protection, it is important to explain the cross‐country differences. The paper analyzes the factors that are crucial in explaining redistributive demands across developing countries with a special emphasis on beliefs about social competition. While ideas about luck versus effort in determining economic prospects are explanatory in every country, our findings also suggest that in societies with high economic volatility the role of beliefs is amplified. Vast fluctuations in economic performance fuel the opinion that economic failure is a result of systemic characteristics, and individuals are not necessarily held fully responsible for their material faiths in such settings. Therefore, government is assigned a greater role in basic provisioning.
Diabetes Attitudes, Wishes and Needs second study (DAWN2™): Cross‐national comparisons on barriers and resources for optimal care—healthcare professional perspective
Authors: Holt R. I. G. , Nicolucci A. , Kovacs Burns K. , Escalante M. , Forbes A. , Hermanns N. , Kalra S. , Massi‐Benedetti M. , Mayorov A. , Menéndez‐Torre E. , Munro N. , Skovlund S. E. , Tarkun I. , Wens J. , Peyrot M. ,   the DAWN2 Study Group
Published: May 2013

Aims

The second Diabetes Attitudes, Wishes and Needs (DAWN2) study sought cross‐national comparisons of perceptions on healthcare provision for benchmarking and sharing of clinical practices to improve diabetes care.

Methods

In total, 4785 healthcare professionals caring for people with diabetes across 17 countries participated in an online survey designed to assess diabetes healthcare provision, self‐management and training.

Results

Between 61.4 and 92.9% of healthcare professionals felt that people with diabetes needed to improve various self‐management activities; glucose monitoring (range, 29.3–92.1%) had the biggest country difference, with a between‐country variance of 20%. The need for a major improvement in diabetes self‐management education was reported by 60% (26.4–81.4%) of healthcare professionals, with a 12% between‐country variance. Provision of diabetes services differed among countries, with many healthcare professionals indicating that major improvements were needed across a range of areas, including healthcare organization [30.6% (7.4–67.1%)], resources for diabetes prevention [78.8% (60.4–90.5%)], earlier diagnosis and treatment [67.9% (45.0–85.5%)], communication between team members and people with diabetes [56.1% (22.3–85.4%)], specialist nurse availability [63.8% (27.9–90.7%)] and psychological support [62.7% (40.6–79.6%)]. In some countries, up to one third of healthcare professionals reported not having received any formal diabetes training. Societal discrimination against people with diabetes was reported by 32.8% (11.4–79.6%) of participants.

Conclusions

This survey has highlighted concerns of healthcare professionals relating to diabetes healthcare provision, self‐management and training. Identifying between‐country differences in several areas will allow benchmarking and sharing of clinical practices.
Insulin degludec improves glycaemic control with lower nocturnal hypoglycaemia risk than insulin glargine in basal–bolus treatment with mealtime insulin aspart in Type 1 diabetes (BEGIN® Basal–Bolus Type 1): 2‐year results of a randomized clinical trial
Authors: Bode B. W. , Buse J. B. , Fisher M. , Garg S. K. , Marre M. , Merker L. , Renard E. , Russell‐Jones D. L. , Hansen C. T. , Rana A. , Heller S. R. ,   BEGIN Basal–Bolus Type 1 Trial Investigators
Published: May 2013

Aims

The goal of this study was to compare the long‐term safety and efficacy of the basal insulin analogue, insulin degludec with insulin glargine (both with insulin aspart) in Type 1 diabetes, over a 2‐year time period.

Methods

This open‐label trial comprised a 1‐year main trial and a 1‐year extension. Patients were randomized to once‐daily insulin degludec or insulin glargine and titrated to pre‐breakfast plasma glucose values of 3.9–4.9 mmol/l.

Results

The rate of nocturnal confirmed hypoglycaemia was 25% lower with insulin degludec than with insulin glargine (P = 0.02). Rates of confirmed hypoglycaemia, severe hypoglycaemia and adverse events, and reductions in glycated haemoglobin and fasting plasma glucose were similar between groups. Despite achieving similar glycaemic control, insulin degludec‐treated patients used 12% less basal and 9% less total daily insulin than did insulin glargine‐treated patients (P < 0.01).

Conclusions

Long‐term basal therapy using insulin degludec in Type 1 diabetes required lower doses and was associated with a 25% lower risk for nocturnal hypoglycaemia than insulin glargine.
Options for prandial glucose management in type 2 diabetes patients using basal insulin: addition of a short‐acting GLP‐1 analogue versus progression to basal‐bolus therapy
Authors: Hirsch I. B. , Buse J. B. , Leahy J. , McGill J. B. , Peters A. , Rodbard H. W. , Rubin R. R. , Skyler J. S. , Verderese C. A. , Riddle M. C.
Published: May 2013

Integrating patient‐centered diabetes care and algorithmic medicine poses particular challenges when optimized basal insulin fails to maintain glycaemic control in patients with type 2 diabetes. Multiple entwined physiological, psychosocial and systems barriers to insulin adherence are not easily studied and are not adequately considered in most treatment algorithms. Moreover, the limited number of alternatives to add‐on prandial insulin therapy has hindered shared decision‐making, a central feature of patient‐centered care. This article considers how the addition of a glucagon‐like peptide 1 (GLP‐1) analogue to basal insulin may provide new opportunities at this stage of treatment, especially for patients concerned about weight gain and risk of hypoglycaemia. A flexible framework for patient–clinician discussions is presented to encourage development of decision‐support tools applicable to both specialty and primary care practice.
Targeting inflammatory pathways in myocardial infarction
Authors: Christia Panagiota , Frangogiannis Nikolaos G.
Published: May 2013

Acute cardiomyocyte necrosis in the infarcted heart generates damage‐associated molecular patterns (DAMPs), activating complement and Toll‐Like Receptor (TLR)/Interleukin (IL)‐1 signalling and triggering an intense inflammatory reaction. Infiltrating leucocytes clear the infarct from dead cells, while activating reparative pathways that lead to formation of a scar. As the infarct heals the ventricle remodels, the geometric, functional and molecular alterations associated with postinfarction remodelling are driven by the inflammatory cascade and are involved in the development of heart failure. Because unrestrained inflammation in the infarcted heart induces matrix degradation and cardiomyocyte apoptosis, timely suppression of the postinfarction inflammatory reaction may be crucial to protect the myocardium from dilative remodelling and progressive dysfunction. Inhibition and resolution of postinfarction inflammation involve mobilization of inhibitory mononuclear cell subsets and require activation of endogenous STOP signals. Our manuscript discusses the basic cellular and molecular events involved in initiation, activation and resolution of the postinfarction inflammatory response, focusing on identification of therapeutic targets. The failure of anti‐integrin approaches in patients with myocardial infarction and a growing body of experimental evidence suggest that inflammation may not increase ischaemic cardiomyocyte death, but accentuates matrix degradation causing dilative remodelling. Given the pathophysiologic complexity of postinfarction remodelling, personalized biomarker‐based approaches are needed to target patient subpopulations with dysregulated inflammatory and reparative responses. Inhibition of pro‐inflammatory signals (such as IL‐1 and monocyte chemoattractant protein‐1) may be effective in patients with defective resolution of postinfarction inflammation who exhibit progressive dilative remodelling. In contrast, patients with predominant hypertrophic/fibrotic responses may benefit from anti‐TGF strategies.
Land use intensification in grasslands: higher trophic levels are more negatively affected than lower trophic levels
Authors: Herbst Christine , Wäschke Nicole , Barto E. Kathryn , Arnold Sabrina , Geuß Daniel , Halboth Ivonne , Reschke Sabina , Sänger Jakob , Meiners Torsten , Obermaier Elisabeth
Published: May 2013

Increasing land use intensity and human influence are leading to a reduction in plant and animal species diversity. However, little is known about how these changes may affect higher trophic levels, apart from simply reducing species numbers. Here we investigated, over 3 years, the influence of different land practices on a tritrophic system in grassland habitats. The system consisted of the host plant Plantago lanceolata L. (Plantaginaceae), two monophagous weevils, Mecinus labilis Herbst and Mecinus pascuorum Gyllenhal (Coleoptera: Curculionidae), and their parasitoid Mesopolobus incultus Walker (Hymenoptera: Pteromalidae). At over 70 sites across three geographic regions in Germany, we measured plant species diversity and vegetation structure, as well as abundance of P. lanceolata, the two weevils, and the parasitoid. Land use intensity (fertilization) and type (mowing vs. grazing) negatively affected not only plant species richness but also the occurrence of the two specialized herbivores and their parasitoid. In contrast, land use had a mostly positive effect on host plant size, vegetation structure, and parasitization rate. This study reveals that intensification of land use influences higher trophic organisms even without affecting the availability of the host plant. The observed relationships between land use, vegetation complexity, and the tritrophic system are not restricted locally; rather they are measureable along a broad range of environmental conditions and years throughout Germany. Our findings may have important implications for the conservation of insect species of nutrient‐poor grasslands.
Irrigation of the apical root canal
Authors: Park Ellen , Shen Ya , Haapasalo Markus
Published: May 2013

Effective apical irrigation is one of the most important root canal procedures that has stood as a long‐standing challenge for the clinician. Despite the myriad of technological advances seen in the last few decades such as nickel–titanium rotary files of various designs and new irrigation delivery systems, very few seem to reliably impact upon a clinician's ability to deliver and replenish irrigant in the most apical part of a root canal. Replenishing irrigant in the apical third is complicated by the multitude of factors that affect the efficacy of this procedure. The current research provides detailed insight on how the principles of fluid mechanics work to explain the physical impediments to thorough irrigation, and how the biological impediments, in the form of biofilm, prevent disinfection despite adequate irrigation. The recent introduction of new irrigation and agitation modalities, coupled with a new understanding of the old problem through novel research techniques, provides a vision to the future and will establish a new standard of irrigation in this field.
Irrigation: beyond the smear layer
Authors: Haapasalo Markus , Qian Wei , Shen Ya
Published: May 2013

Traditionally, much of the attention placed on irrigation in endodontics has focused on smear layer removal. While the smear layer continues to be a relevant topic, other areas related to irrigation and irrigants have emerged that also require a more in‐depth analysis and understanding. This review starts with the smear layer, partially from a new angle, and expands into other topics such as uninstrumented root canal areas, and effect of irrigation in lateral canals and dentin canals. Advanced microbiological models for irrigation research will be presented and discussed. The effect of sodium hypochlorite and decalcifying solutions on dentin structure and dentin strength has become an important topic, which is related to the possible harmful effects of irrigation such as dentin erosion and even vertical root fracture. The impact of irrigant sequence and time of exposure will also be discussed, and recommendations for irrigation protocols will be made.
Update on endodontic irrigating solutions
Authors: Basrani Bettina , Haapasalo Markus
Published: May 2013

Bacteria have long been recognized as the primary etiological factor in the development of pulp and periapical lesions. Successful root canal therapy depends on thorough debridement of pulpal tissue, dentin debris, and infective microorganisms. Currently, it is impossible to eradicate intraradicular infection with mechanical instrumentation alone. Therefore, irrigants are required to complete this task. In this article, the different actions and interactions of the most commonly used irrigants are discussed. The aim of this review is to analyze the relevant literature on root canal irrigants.
Ozone and SIRT3: an unexplored paradigm
Authors: Syed Deeba N. , Mukhtar Hasan
Published: May 2013

Exposure to environmentally relevant doses of ozone induces oxidative stress and is associated with adverse effects at tissue level. Delineating the role of sirtuin3, involved in cellular energy homoeostasis, in the response of skin to ozone can be a step towards developing prevention strategies against cutaneous pathologies.
Managing fisheries for human and food security
Authors: McClanahan Tim , Allison Edward H , Cinner Joshua E
Published: May 2013

We evaluate the current status of the global marine fisheries using the frameworks of conflict, food security and vulnerability. Existing trends suggest that there is likely to be greater food insecurity and fisheries conflicts due to issues such as: declining fishery resources; a North–South divide in investment; changing consumption patterns; increasing reliance on fishery resources for coastal communities; and inescapable poverty traps creating by low net resource productivity and few alternatives. Consequently, managing fisheries from a food security perspective will become increasingly necessary, and we therefore briefly review fisheries from the perspective of food security and evaluate it using a vulnerability framework. Specifically, we describe three key components of vulnerability (exposure, sensitivity and adaptive capacity) for selected fisheries. This is followed by proposals to build the adaptive capacity of fisheries and recommendations to avoid future conflicts. Adaptive capacity attributes include assets, social flexibility and organization attributes, and learning. We present some key ways to build these aspects of the fishery to reduce the many potential environmental and social threats that increase the vulnerability of fisheries. Recommendations include fewer subsidies, reduced capital investment, precautionary management to minimize risks of ecosystem collapse, conservation of remaining resources, diversified portfolios of production and markets, and greater equity in contracts and distribution. Further, we recommend a contextual diagnostic and environmental justice framework to assess a range of options for fishery governance.
Modulating protein stability – directed evolution strategies for improved protein function
Authors: Socha Raymond D. , Tokuriki Nobuhiko
Published: May 2013

Protein engineering is widely used to generate proteins with novel or enhanced function. However, manipulating protein function in the laboratory can prove laborious, protracted and challenging. Recent developments in the understanding of protein evolutionary dynamics have unveiled the full extent by which the evolution of function is limited by protein stability ‐ a revelation that may be applied to protein engineering on a whole. Thus, strategies that modulate protein stability and reduce its constraining effects may facilitate the engineering of protein function. A combinatorial approach involving the introduction of compensatory mutations and manipulation of the stability threshold by chaperone buffering during directed evolution can improve the functional adaptation of a protein, thereby fostering our ability to attain ever‐more ambitious protein functions in the laboratory.
The recognition and removal of cellular poly(ADP‐ribose) signals
Authors: Barkauskaite Eva , Jankevicius Gytis , Ladurner Andreas G. , Ahel Ivan , Timinszky Gyula
Published: May 2013

Poly(ADP‐ribosyl)ation is involved in the regulation of a variety of cellular pathways, including, but not limited to, transcription, chromatin, DNA damage and other stress signalling. Similar to other tightly regulated post‐translational modifications, poly(ADP‐ribosyl)ation employs ‘writers’, ‘readers’ and ‘erasers’ to confer regulatory functions. The generation of poly(ADP‐ribose) is catalyzed by poly(ADP‐ribose) polymerase enzymes, which use NAD+ as a cofactor to sequentially transfer ADP‐ribose units generating long polymers, which, in turn, can affect protein function or serve as a recruitment platform for additional factors. Historically, research has focused on poly(ADP‐ribose) generation pathways, with knowledge about PAR recognition and degradation lagging behind. Over recent years, several discoveries have significantly furthered our understanding of poly(ADP‐ribose) recognition and, even more so, of poly(ADP‐ribose) degradation. In this review, we summarize current knowledge about the protein modules recognizing poly(ADP‐ribose) and discuss the newest developments on the complete reversibility of poly(ADP‐ribosyl)ation.
Individual and combined effects of fine sediment and the herbicide glyphosate on benthic macroinvertebrates and stream ecosystem function
Authors: Magbanua Francis S. , Townsend Colin R. , Hageman Kimberly J. , Matthaei Christoph D.
Published: May 2013

Previous research on the combined action of various paired agricultural stressors in stream ecosystems has shown that non‐additive outcomes (i.e. synergisms or antagonisms) are more common than simple additive effects on communities, but the interplay between deposited fine sediment and widely used herbicides such as glyphosate as stressors is not well understood.

A 28‐day experiment in outdoor stream mesocosms simulated effects of varying levels of fine sediment and a glyphosate‐based herbicide on macroinvertebrates and ecosystem function (leaf breakdown) in a fully factorial repeated‐measures design. Our aim was to determine whether (i) increased levels of sediment and glyphosate had individual and/or additive combined effects on invertebrates and leaf breakdown, (ii) increased sediment reduced the toxicity of glyphosate (antagonistic multiple stressor interaction) or (iii) sediment‐adsorbed glyphosate prolonged the effects of exposure (synergistic interaction).

Sediment addition positively or negatively affected eight of the 10 most common invertebrate taxa colonising the mesocosms and increased or decreased the representation of 12 of 15 biological trait categories possessed by the invertebrates, while glyphosate addition negatively affected only two taxa and two invertebrate trait categories, indicating that glyphosate entering streams as a result of herbicide addition to farmland is less likely to be problematic for invertebrates than fine sediment from catchment erosion.

No significant overall sediment‐by‐glyphosate interaction was detected for invertebrate taxonomic or trait compositions or for any common individual taxon, trait or community metric, indicating that the two stressors were acting additively (i.e. without interaction), rather than synergistically or antagonistically.

Leaf breakdown rates (measured as mass and strength loss) were accelerated by sediment and glyphosate as individual stressors. Further, the two stressors interacted for leaf strength loss, with their combined effect being less than additive when both stressors were at their highest levels.

Population, community and ecosystem variables responded differently to multiple stressors, highlighting the value of combining structural, functional taxonomic and trait data to assess the effects of anthropogenic stressors.
Environmental, spatial and phylogenetic determinants of fish life‐history traits and functional composition of Australian rivers
Authors: Sternberg David , Kennard Mark J.
Published: May 2013

The biogeography of freshwater fish is determined in part by large‐scale filters such as phylogenetic history, the spatial arrangement of catchments and environmental variability. Species are filtered from the regional pool if they possess a combination of functional traits enabling them to persist in the local environment. This article aims to quantify the relative importance of these large‐scale filters in determining spatial variation in freshwater fish life‐history traits and functional trait composition of Australian river basins.

We developed a database of 10 life‐history traits for 141 native freshwater fish species and compiled species distribution data for 123 river basins across the Australian continent. In order to partition the variation in the representation of life‐history trait into unique and overlapping components, we also quantified the degree of phylogenetic relatedness among species, the geographical arrangement of river basins throughout the landscape and 12 broad‐scale environmental factors. We then related life‐history trait composition to gradients of environmental variation by constrained multivariate ordination and simple linear regression.

Our explanatory matrices accounted for 86.8% of the total variation in life‐history trait composition at the river basin scale, of which 59.4% could be attributed to phylogeny and spatially structured environmental variation. This component represents the overlap among the broad‐scale filtering processes of phylogenetic history, spatial autocorrelation and environmental variability in accounting for the distribution of life‐history traits across Australian river basins.

Our analysis showed strong associations between suites of life‐history traits that define generation time and reproductive output and a strong climate–hydrological gradient across the landscape. We also showed significant correlations between specific environmental variables and a number of key life‐history traits that highlight the importance of trait‐mediated environmental filters at broad spatial scales.

This study advances our conceptual understanding of broad‐scale community assembly theory and has revealed trait–environment relationships at scales relevant to restoration and conservation of aquatic biodiversity. Our study provides greater insight into the determinants of spatial variation in fish species distributions and potentially addresses key scientific challenges, such as understanding how fish communities are assembled, and identifies the potential threats to, and responses of, these communities caused by environmental change.
Drought response of five conifer species under contrasting water availability suggests high vulnerability of Norway spruce and European larch
Authors: Lévesque Mathieu , Saurer Matthias , Siegwolf Rolf , Eilmann Britta , Brang Peter , Bugmann Harald , Rigling Andreas
Published: May 2013

The ability of tree species to cope with anticipated decrease in water availability is still poorly understood. We evaluated the potential of Norway spruce, Scots pine, European larch, black pine, and Douglas‐fir to withstand drought in a drier future climate by analyzing their past growth and physiological responses at a xeric and a mesic site in Central Europe using dendroecological methods. Earlywood, latewood, and total ring width, as well as the δ13C and δ18O in early‐ and latewood were measured and statistically related to a multiscalar soil water deficit index from 1961 to 2009. At the xeric site, δ13C values of all species were strongly linked to water deficits that lasted longer than 11 months, indicating a long‐term cumulative effect on the carbon pool. Trees at the xeric site were particularly sensitive to soil water recharge in the preceding autumn and early spring. The native species European larch and Norway spruce, growing close to their dry distribution limit at the xeric site, were found to be the most vulnerable species to soil water deficits. At the mesic site, summer water availability was critical for all species, whereas water availability prior to the growing season was less important. Trees at the mesic were more vulnerable to water deficits of shorter duration than the xeric site. We conclude that if summers become drier, trees growing on mesic sites will undergo significant growth reductions, whereas at their dry distribution limit in the Alps, tree growth of the highly sensitive spruce and larch may collapse, likely inducing dieback and compromising the provision of ecosystem services. However, the magnitude of these changes will be mediated strongly by soil water recharge in winter and thus water availability at the beginning of the growing season.
Dampening effects of long‐term experimental drought on growth and mortality rates of a Holm oak forest
Authors: Barbeta Adrià , Ogaya Romà , Peñuelas Josep
Published: May 2013

Forests respond to increasing intensities and frequencies of drought by reducing growth and with higher tree mortality rates. Little is known, however, about the long‐term consequences of generally drier conditions and more frequent extreme droughts. A Holm oak forest was exposed to experimental rainfall manipulation for 13 years to study the effect of increasing drought on growth and mortality of the dominant speciesQuercus ilex,Phillyrea latifolia,andArbutus unedo. The drought treatment reduced stem growth ofA. unedo(−66.5%) andQ. ilex(−17.5%), whereasP. latifoliaremained unaffected. Higher stem mortality rates were noticeable inQ. ilex(+42.3%), but not in the other two species. Stem growth was a function of the drought index of early spring in the three species. Stem mortality rates depended on the drought index of winter and spring forQ. ilexand in spring and summer forP. latifolia,but showed no relation to climate inA. unedo. Following a long and intense drought (2005–2006), stem growth ofQ. ilexandP. latifoliaincreased, whereas it decreased inA. unedo.Q. ilexalso enhanced its survival after this period. Furthermore, the effect of drought treatment on stem growth inQ. ilexandA. unedowas attenuated as the study progressed. These results highlight the different vulnerabilities of Mediterranean species to more frequent and intense droughts, which may lead to partial species substitution and changes in forest structure and thus in carbon uptake. The response to drought, however, changed over time. Decreased intra‐ and interspecific competition after extreme events with high mortality, together with probable morphological and physiological acclimation to drought during the study period, may, at least in the short term, buffer forests against drier conditions. The long‐term effects of drought consequently deserve more attention, because the ecosystemic responses are unlikely to be stable over time.Nontechnical summaryIn this study, we evaluate the effect of long‐term (13 years) experimental drought on growth and mortality rates of three forest Mediterranean species, and their response to the different intensities and durations of natural drought. We provide evidence for species‐specific responses to drought, what may eventually lead to a partial community shift favoring the more drought‐resistant species. However, we also report a dampening of the treatment effect on the two drought‐sensitive species, which may indicate a potential adaptation to drier conditions at the ecosystem or population level. These results are thus relevant to account for the stabilizing processes that would alter the initial response of ecosystem to drought through changes in plant physiology, morphology, and demography compensation.
Consequences of the introduction of exotic and translocated species and future extirpations on the functional diversity of freshwater fish assemblages
Authors: Matsuzaki Shin‐ichiro S. , Sasaki Takehiro , Akasaka Munemitsu
Published: May 2013

Aim

To explore the effects of the introduction of exotic and translocated species and possible future extirpation of native species on the functional diversity (FD) of freshwater fish assemblages.

Location

Japanese archipelago.

Methods

We examined spatio‐temporal changes in species richness, FD, functional richness (the number of trait‐based functional groups), and the functional group composition between historical and current fish assemblages for 27 eco‐regions, and compared the relative effects of the introduction of exotic and translocated species on FD. We also used a null model approach to determine the assembly patterns and the extent of functional redundancy. Finally, we determined the effect of the loss of endangered species on FD by comparing the observed losses with simulated random loss.

Results

Through the introductions of non‐native species, the species richness, FD and functional richness of the fish assemblages increased 2.4‐, 1.6‐ and 2.1‐fold, respectively. The functional group composition also changed largely through the additions of new functional groups. Exotic species had a significantly greater effect size than translocated species, but there were no differences in the overall net effects of exotic and translocated species. Null modelling approaches showed that the observed FD was higher than expected by chance (i.e. trait divergent) in both historical and current assemblages. There was also low functional redundancy. In our simulation, FD decreased in proportion to the loss of species, independent of whether the species were endangered.

Main conclusions

We demonstrated that both exotic and translocated species may change FD and functional group composition, which might have dramatic consequences for ecosystem processes. We suggest that the future extirpation of even a few native species can cause a substantial loss of FD. Our findings emphasize the need to improve conservation strategies based on species richness and conservation status, and to incorporate translocated species into targets of the management of non‐native species.
Phenotypic and phylogenetic correlates of geographic range size inCanadian freshwater fishes
Authors: Blanchet Simon , Reyjol Yorick , April Julien , Mandrak Nicholas E. , Rodríguez Marco A. , Bernatchez Louis , Magnan Pierre
Published: May 2013

Aim

We investigated the relationship between geographic range size (GRS), longitude and latitude (Rapoport's rule) inCanadian freshwater fishes. We tested hypotheses regarding the phenotypic and phylogenetic determinants ofGRSto unravel processes driving the spatial patterns ofGRSinCanada. BecauseGRSis negatively correlated with extinction risk, we also aimed at identifying biological proxies that may be used to predict extinction risks.

Location

North‐America,CanadianShield.

Methods

We built a database combining range area, seven ecological traits, and a molecular phylogeny for nativeCanadian freshwater fishes. We tested latitudinal and longitudinal patterns inGRSby the mean ofPearson correlations. We combined phylogenetic generalized least squares (PGLS) models and a model selection procedure to tease apart hypotheses (and hence ecological traits) that best explainedGRSin our dataset.PGLSs were also used to explore relationships between ecological traits, phylogeny, and species mid‐range latitude and longitude. Partial regressions were used to determine direct and indirect relationships driving spatial patterns ofGRSinCanadian freshwater fishes.

Results

There was a significant and positive correlation betweenGRS, latitude and longitude. According toPGLSs, three ecological traits, related to the habitat use, migratory and thermal tolerance hypotheses, were significantly correlated withGRS, mid‐range longitude and mid‐range latitude. Two traits related to locomotion were further related toGRS. There was no phylogenetic effect onGRS(i.e. no phylogenetic conservatism). Partial regressions revealed complex direct and indirect relationships between ecological traits, mid‐range latitude, mid‐range longitude andGRS.

Main conclusions

Our results show that traits related to the ability to use dispersal corridors, as well as traits directly related to mobility, are useful in understanding biodiversity patterns such as Rapoport's rule. However, because of a weak explanatory power, we conclude that using biological proxies ofGRSto predict species at risk of extinction would be premature.
Phylogenetic beta diversity of angiosperms in North America
Authors: Qian Hong , Swenson Nathan G. , Zhang Jinlong
Published: May 2013

Aim

Ecologists have generally agreed that beta diversity is a key component of global patterns of species richness. Incorporating phylogenetic information into the study of beta diversity allows researchers to identify the degree to which the shared evolutionary histories of species explain ecological patterns observed today. For example, phylogenetic analyses can determine whether closely related species tend to occupy similar positions along broad climatic gradients and whether this explains the compositional turnover along these gradients. Despite the promise of phylogenetic beta diversity analyses, few continental‐scale investigations exist. Here, we quantify the phylogenetic beta diversity and taxonomic beta diversity of the angiosperm flora across North America. We relate these metrics to one another and to geographical and environmental distances to uncover the phylogenetic signal underlying species compositional turnover.

Location

North America.

Method

Seventy‐one regional floras were used and assigned into five latitudinal zones and two longitudinal bands. The Sørensen index and PhyloSor index were used to quantify taxonomic similarity and phylogenetic similarity, respectively, between floras, and were related to geographical and environmental distances.

Results

Phylogenetic similarity between floras is strongly correlated with taxonomic similarity, is higher in eastern North America than in western North America, and increases strikingly with latitude. Geographical and environmental distances together explained on average about 76% of the variation in phylogenetic beta diversity with environmental distance explaining more variation in phylogenetic similarity in three of the four latitudinal bands examined.

Main conclusions

The results show that phylogenetic beta diversity is consistently lower than taxonomic beta diversity, which suggests that the spatial turnover of species in the study system is predominantly the spatial turnover of closely related species and not distantly related species. Thus, the turnover of angiosperm floras in North America is best explained by small divergences along environmental axes for closely related species and a gradual turnover of lineages through space.
Chronic ethanol diet increases regulatory T‐cell activity and inhibits hepatitis C virus core‐specific cellular immune responses in mice
Authors: Ortiz Vivian , Wands Jack R.
Published: May 2013

Aim

Chronic ethanol consumption is associated with persistent hepatitis C viral (HCV) infection. This study explores the role of the host cellular immune response to HCV core protein in a murine model and how chronic ethanol consumption alters T‐cell regulatory (Treg) populations.

Methods

BALB/c mice were fed an isocaloric control or ethanol liquid diet. Dendritic cells (DC) were isolated after expansion with a hFl3tL‐expression plasmid and subsequently transfected with HCV core protein. Core‐containing DC (1 × 106) were s.c. injected (×3) in mice every 2 weeks. Splenocytes from immunized mice were isolated and stimulated with HCV core protein to measure generation of viral antigen‐specific Treg, as well as secretion of interleukin (IL)‐2, tumor necrosis factor (TNF)‐α and IL‐4. Cytotoxicity was measured by lactate dehydrogenase release from HCV core‐expressing syngeneic SP2/19 myeloma cells.

Results

Splenocytes from mice immunized with ethanol‐derived and HCV core‐loaded DC exhibited significantly lower in vitro cytotoxicity compared to mice immunized with HCV core‐loaded DC derived from isocaloric pair‐fed controls. Stimulation with HCV core protein triggered higher IL‐2, TNF‐α and IL‐4 release in splenocytes following immunization with core‐loaded DC derived from controls as compared to chronic ethanol‐fed mice. Splenocytes derived from mice immunized with core‐loaded DC isolated from ethanol‐fed mice exhibited a significantly higher CD25+FOXP3+ and CD4+FOXP3+Treg population.

Conclusion

These results suggest that immunization with HCV core‐containing DC from ethanol‐fed mice induces an increase in the CD25+FOXP3+ and CD4+FOXP3+Treg population and may suppress HCV core‐specific CD4+ and CD8+ T‐cell immune responses.