bluuebunny/crossref_metadata_2025_split huggingface dataset:
Species distribution models of an endangered rodent offer conflicting measures of habitat quality at multiple scales
Authors: Bean William T. , Prugh Laura R. , Stafford Robert , Butterfield H. Scott , Westphal Michael , Brashares Justin S. 
Published: May 2014

Summary

The high cost of directly measuring habitat quality has led ecologists to test alternate methods for estimating and predicting this critically important ecological variable. In particular, it is frequently assumed but rarely tested that models of habitat suitability (‘species distribution models’, SDMs) may provide useful indices of habitat quality, either from an individual animal or manager's perspective. Critically, SDMs are increasingly used to estimate species’ ranges, with an implicit assumption that areas of high suitability will result in higher probability of persistence. This assumption underlies efforts to use SDMs to design protected areas, assess the status of cryptic species or manage responses to climate change. Recent tests of this relationship have provided mixed results, suggesting SDMs may predict abundance but not other measures of high‐quality habitat (e.g. survival, persistence).

In this study, we created a suite of SDMs for the endangered giant kangaroo rat Dipodomys ingens at three distinct scales using the machine‐learning method Maxent. We compared these models with three measures of habitat quality: survival, abundance and body condition.

Species distribution models were not correlated with survival, while models at all scales were positively correlated with abundance. Finer‐scale models were more closely correlated with abundance than the largest scale. Body condition was not correlated with habitat suitability at any scale. The inability of models to predict survival may be due to a lack of information in environmental covariates; unmeasured community processes or stochastic events; or the inadequacy of using models that predict species presence to also predict demography.

Synthesis and applications. Species distribution models (SDMs), especially fine scale ones, may be useful for longer‐term management goals, such as identifying high‐quality habitat for protection. However, short‐term management decisions should be based only on models that use covariates appropriate for the necessary temporal and spatial scales. Assumptions about the relationship between habitat suitability and habitat quality must be made explicit. Even then, care should be taken in inferring multiple types of habitat quality from SDMs.
The devil is in the dispersers: predictions of landscape connectivity change with demography
Authors: Elliot Nicholas B. , Cushman Samuel A. , Macdonald David W. , Loveridge Andrew J. 
Published: May 2014

Summary

Concern about the effects of habitat fragmentation has led to increasing interest in dispersal and connectivity modelling. Most modern techniques for connectivity modelling have resistance surfaces as their foundation. However, resistance surfaces for animal movement are frequently estimated without considering dispersal, despite being the principal natural mechanism by which organisms move between populations.

We collected Global Positioning System data over 10 years from 50 African lions Panthera leo (11 male natal dispersers, 20 adult males and 19 adult females) and used a path level analysis to parameterize demographic‐specific resistance surfaces for the Kavango Zambezi Transfrontier Conservation Area (KAZA) in Southern Africa.

Lion path selection varied according to demographic grouping: adult females were most averse to risky landscapes such as agro‐pastoral lands, towns, areas of high human density and highways. Male natal dispersers were the least‐risk averse suggesting they are potentially the most prone demographic to human–lion conflict. Adults of both sexes selected bushed grassland and shrubland habitats and avoided woodland. Male natal dispersers displayed the opposite trend suggesting con‐specific avoidance and/or suboptimal habitat use.

We used the resistance surfaces to calculate factorial least‐cost path networks for each demographic‐specific resistance surface and present results that show substantial differences between predicted patterns of connectivity for male natal dispersers, adult females and adult males.

Synthesis and applications. Resistance surfaces are widely used to create connectivity models, which are promoted for use by conservation managers. Our results suggest that the demographic category used to parameterize resistance surfaces may lead to radically different conclusions about connectivity. Failure to include dispersing individuals when parameterizing resistance surfaces intended for connectivity modelling may lead to erroneous conclusions about connectivity and potentially unsound management strategies.
Crop monoculture rather than agriculture reduces the spatial turnover of soil bacterial communities at a regional scale
Authors: Figuerola Eva L. M. , Guerrero Leandro D. , Türkowsky Dominique , Wall Luis G. , Erijman Leonardo 
Published: May 2014

SummaryThe goal of this study was to investigate the spatial turnover of soil bacterial communities in response to environmental changes introduced by the practices of soybean monoculture or crop rotations, relative to grassland soils. Amplicon sequencing of the 16S rRNA gene was used to analyse bacterial diversity in producer fields through three successive cropping cycles within one and a half years, across a regional scale of the Argentinean Pampas. Unlike local diversity, which was not significantly affected by land use type, agricultural management had a strong influence on β‐diversity patterns. Distributions of pairwise distances between all soils samples under soybean monoculture had significantly lower β‐diversity and narrower breadth compared with distributions of pairwise distances between soils managed with crop rotation. Interestingly, good agricultural practices had similar degree of β‐diversity as natural grasslands. The higher phylogenetic relatedness of bacterial communities in soils under monoculture across the region was likely determined by the observed loss of endemic species, and affected mostly to phyla with low regional diversity, such as Acidobacteria, Verrucomicrobia and the candidates phyla SPAM and WS3. These results suggest that the implementation of good agricultural practices, including crop rotation, may be critical for the long‐term conservation of soil biodiversity.
Identification of specific corrinoids reveals corrinoid modification in dechlorinating microbial communities
Authors: Men Yujie , Seth Erica C. , Yi Shan , Crofts Terence S. , Allen Robert H. , Taga Michiko E. , Alvarez‐Cohen Lisa 
Published: May 2014

SummaryCobalamin and other corrinoids are essential cofactors for many organisms. The majority of microbes with corrinoid‐dependent enzymes do not produce corrinoids de novo, and instead must acquire corrinoids produced by other organisms in their environment. However, the profile of corrinoids produced in corrinoid‐dependent microbial communities, as well as the exchange and modification of corrinoids among community members have not been well studied. In this study, we applied a newly developed liquid chromatography tandem mass spectrometry‐based corrinoid detection method to examine relationships among corrinoids, their lower ligand bases and specific microbial groups in microbial communities containing Dehalococcoides mccartyi that has an obligate requirement for benzimidazole‐containing corrinoids for trichloroethene respiration. We found that p‐cresolylcobamide ([p‐Cre]Cba) and cobalamin were the most abundant corrinoids in the communities. It suggests that members of the family Veillonellaceae are associated with the production of [p‐Cre]Cba. The decrease of supernatant‐associated [p‐Cre]Cba and the increase of biomass‐associated cobalamin were correlated with the growth of D. mccartyi by dechlorination. This supports the hypothesis that D. mccartyi is capable of fulfilling its corrinoid requirements in a community through corrinoid remodelling, in this case, by importing extracellular [p‐Cre]Cba and 5,6‐dimethylbenzimidazole (DMB) (the lower ligand of cobalamin), to produce cobalamin as a cofactor for dechlorination. This study also highlights the role of DMB, the lower ligand produced in all of the studied communities, in corrinoid remodelling. These findings provide novel insights on roles played by different phylogenetic groups in corrinoid production and corrinoid exchange within microbial communities. This study may also have implications for optimizing chlorinated solvent bioremediation.
Global ubiquity and local endemism of free‐living terrestrial protists: phylogeographic assessment of the streptophyte alga Klebsormidium
Authors: Ryšánek David , Hrčková Kristýna , Škaloud Pavel 
Published: May 2014

SummaryDespite considerable research attention during the last 10 years, the distribution and biogeography of protists remain as highly controversial issues. The presumably huge population sizes and unlimited dispersal capabilities should result in protist ubiquity. However, recent molecular investigations suggest that protist communities exhibit strong biogeographic patterns. Here, we examined the biogeographic pattern of a very common green algal genus Klebsormidium. We evaluated the geographic distribution of rbcL genotypes for 190 isolates sampled in six sampling regions located in Europe, North America and Asia. Measures of correlation between genetic and geographic distance matrices revealed a differential distribution pattern on two geographic levels. Globally, the populations were genetically homogeneous; locally, the genotypes were patchily distributed. We hypothesized that a local fine‐scale structuring of genotypes may be caused by various ecological factors, in particular, by the habitat differentiation of particular genotypes. Our investigations also identified a large number of new, previously unrecognized lineages. A total of 44 genotypes were identified and more than 66% of these were reported for the first time.
Oral cavity contains distinct niches with dynamic microbial communities
Authors: Xu Xin , He Jinzhi , Xue Jing , Wang Yan , Li Kun , Zhang Keke , Guo Qiang , Liu Xianghong , Zhou Yuan , Cheng Lei , Li Mingyun , Li Yuqing , Li Yan , Shi Wenyuan , Zhou Xuedong 
Published: May 2014

SummaryMicrobes colonize human oral surfaces within hours after delivery. During postnatal development, physiological changes, such as the eruption of primary teeth and replacement of the primary dentition with permanent dentition, greatly alter the microbial habitats, which, in return, may lead to community composition shifts at different phases in people's lives. By profiling saliva, supragingival and mucosal plaque samples from healthy volunteers at different ages and dentition stages, we observed that the oral cavity is a highly heterogeneous ecological system containing distinct niches with significantly different microbial communities. More importantly, the phylogenetic microbial structure varies with ageing. In addition, only a few taxa were present across the whole populations, indicating a core oral microbiome should be defined based on age and oral niches.
The evolving dynamics of the microbial community in the cystic fibrosis lung
Authors: McGuigan Luke , Callaghan Máire 
Published: May 2014

SummaryThe cystic fibrosis (CF) lung is a niche colonized by a diverse group of organisms, with a more limited number of species including Pseudomonas aeruginosa dominating in adult patients. Whether all members of this microbial community play a direct or indirect role in pulmonary decline has yet to be fully elucidated, but investigations of their interactions with both co‐colonizing species and with host cells are beginning to shed light on their virulence potential. It is also emerging that some microbial species within this community adapt as chronic infection is established to survive the hostile environment of the lung, to minimize host clearance and to resist therapeutic intervention. This review highlights the recent developments in CF microbiology focusing on the cooperative, competitive and adaptive interactions of established and emerging pathogens in the lung microbiome.
Exploring the diversity of arsenic resistance genes from acid mine drainage microorganisms
Authors: Morgante Verónica , Mirete Salvador , de Figueras Carolina G. , Postigo Cacho Marina , González‐Pastor José E. 
Published: May 2014

SummaryThe microbial communities from the Tinto River, a natural acid mine drainage environment, were explored to search for novel genes involved in arsenic resistance using a functional metagenomic approach. Seven pentavalent arsenate resistance clones were selected and analysed to find the genes responsible for this phenotype. Insights about their possible mechanisms of resistance were obtained from sequence similarities and cellular arsenic concentration. A total of 19 individual open reading frames were analysed, and each one was individually cloned and assayed for its ability to confer arsenic resistance in Escherichia coli cells. A total of 13 functionally active genes involved in arsenic resistance were identified, and they could be classified into different global processes: transport, stress response, DNA damage repair, phospholipids biosynthesis, amino acid biosynthesis and RNA‐modifying enzymes. Most genes (11) encode proteins not previously related to heavy metal resistance or hypothetical or unknown proteins. On the other hand, two genes were previously related to heavy metal resistance in microorganisms. In addition, the ClpB chaperone and the RNA‐modifying enzymes retrieved in this work were shown to increase the cell survival under different stress conditions (heat shock, acid pH and UV radiation). Thus, these results reveal novel insights about unidentified mechanisms of arsenic resistance.
Preparation using Pectinase and Characterization of Nanofibers from Orange Peel Waste in Juice Factories
Authors: Hideno Akihiro , Abe Kentaro , Yano Hiroyuki 
Published: May 2014

AbstractsThis study reports the preparation and characterization of nanofibers consisting mainly of cellulose microfibrils from orange peel (OP), which is a significant byproduct of orange juice production. Three treatments (boiling, alkaline, and pectinase) were investigated with and without subsequent grinding treatment. It was possible to prepare the cellulose nanofibers (CNFs) using these methods, except for the boiling treatment with grinding. Interestingly, only pectinase and a mild‐physical blender treatment without grinding produced nanofibers. The width of the nanofibers from OP was approximately 10 to 50 nm. The microfibril bundles of OP were considered to be thinner than those of commercial CNFs. Our data indicated that the removal of pectic polysaccharides and hemicelluloses covering the cellulose microfibrils was important for the preparation of nanofibers from OP. These nanofibers from OP using pectinase are proposed to be applicable as food materials, pharmaceuticals, and filters for the tractive characteristics of the sheet.
Population attributable risk from obesity to arthritis in the Canadian Population Health Longitudinal Survey 1994–2006
Authors: Mo Frank , Morrison Howard , Neutel Ineke C. 
Published: May 2014

AbstractObjectivesTo examine the relationship, potential associations, and determine the population attributable risk percent (PAR%) between obesity and arthritis in Canadians aged 40 to 79 from 1994 to 2006.MethodsOur study population were the 17 276 respondents in the Canadian National Population Longitudinal Health Survey data, from 1994/1995 to 2006/2007.ResultsRespondents who were overweight and obese increased over time, with arthritis increasing from 20% to 30% over the study period. Women reported a 10% higher prevalence of arthritis than men. Men aged 70–79 and women aged 60–69 were most likely to report arthritis. PAR% calculations indicated that 3.8% of arthritis in 1994 and 7.5% in 2006 in the overall population could be attributed to overweight, while the proportion of arthritis attributable to obesity increased from 7.0% in 1994 to 10.2% in 2006.ConclusionsIncreasing overweight/obesity of the population was positively associated with arthritis in Canada for both sexes. In addition to the many other beneficial health effects, reducing levels of excess weight may result in either less arthritis or fewer manifestations of symptoms of arthritis or both.
Emerging Powers and Change in the Global Financial Order
Authors: Huotari Mikko , Hanemann Thilo 
Published: May 2014

AbstractEmerging economies have become a major force in the world economy. This article examines the role of Brazil, Russia, India and China (BRIC) in global finance and compares their potential to challenge the parameters of international financial and monetary relations. Instead of focusing on changes inside the existing system of multilateral governance, our analysis stresses the need to consider a broader set of channels to develop and exert financial power. Our comparative assessment of BRIC economies' increasing autonomy, their strategic intentions, financial system capacity and the behavior of subnational ‘power brokers' in global financial markets serves as a starting point to advance the debate over ongoing structural changes in the global financial order. We show how increasing autonomy and financial power have already led emerging markets to develop alternatives for crisis financing and development assistance. The prospects for deeper cooperation among BRIC economies however remain gloomy, as the already very diverse preferences with regard to global financial structures can be expected to further diverge.
Fifty years of finance research in the Asia Pacific Basin
Authors: Benson Karen , Faff Robert , Smith Tom 
Published: May 2014

AbstractIn this paper, we review the history of scholarly finance research in the Asia Pacific Basin. We do this by analysing the four leading regional finance journals – Accounting and Finance, Australian Journal of Management, International Review of Finance and the Pacific‐Basin Finance Journal – along five dimensions. The five dimensions are the most cited papers, noted authors, impact in terms of practice, research areas and a breakdown in terms of the development of the field according to Kuhnian concepts of normal science, anomalies and extraordinary science. We show that the Asia Pacific journals make a crucial contribution to research and practice both in the region and internationally.
The minimally invasive MitraClip™ procedure for mitral regurgitation under general anaesthesia: immediate effects on the pulmonary circulation and right ventricular function
Authors: Kottenberg E. , Dumont M. , Frey U. H. , Heine T. , Plicht B. , Kahlert P. , Erbel R. , Peters J. 
Published: May 2014

SummaryA relatively new minimally invasive cardiological procedure, called the MitraClip™, does not require sternotomy and may have a number of advantages compared with open mitral valve surgery, but its acute impact on the pulmonary circulation and right ventricular function during general anaesthesia is unclear. We prospectively assessed the effects of the MitraClip procedure in 81 patients with or without pulmonary hypertension (defined as mean pulmonary artery pressure > 25 mmHg), who were anaesthetised using fentanyl (5 μg.kg−1), etomidate (0.2–0.3 mg.kg−1), rocuronium (0.5–0.6 mg.kg−1) and isoflurane. Placement of the MitraClip led to a 60% increase in mean (SD) right ventricular stroke work index (from 512 (321) to 820 (470) mmHg.ml.m−2, p < 0.0001), while mean (SD) pulmonary vascular resistance index decreased by 24% (522 (330) to 399 (244) dyn.s.cm−5, p < 0.0001), and mean (SD) pulmonary artery pressure decreased by 10% (30 (8) to 27 (8) mmHg, p < 0.0001). Patients with pulmonary hypertension experienced a similar decrease in mean pulmonary artery pressure compared with those without, and they also had a slight reduction in mean (SD) pulmonary artery occlusion pressure (22 (6) down to 20 (6) mmHg, p = 0.044). We conclude that successful MitraClip treatment for mitral regurgitation acutely improves right ventricular performance by reducing right ventricular afterload, regardless of whether patients have pre‐operative pulmonary hypertension.
Endoscopic cyst‐gastrostomy for pancreatic pseudocysts: refining the indications
Authors: Due Steven L. , Wilson Thomas G. , Chung Adrian , Chen John W. C. 
Published: May 2014

AbstractBackgroundPseudocysts are a common consequence of acute pancreatitis and require intervention if symptomatic. Endoscopic management is emerging as a safe and effective alternative to surgery, although its use is not yet widespread.MethodsWe describe our experience of 10 consecutive unselected patients who underwent endoscopic ultrasound‐guided cyst‐gastrostomy and stent insertion at a tertiary referral centre. Technical aspects of the procedure are detailed with accompanying photographs.ResultsSix patients made an uneventful recovery. Four patients developed complications, of which one was successfully salvaged by endoscopy and three required surgery.ConclusionWe discuss technical and patient factors which may have contributed to these complications in the context of current literature, and in particular, found that the presence of necrosis was associated with higher morbidity, both in our series and in others. In our experience, endoscopic ultrasound‐guided cyst‐gastrostomy is best employed in simple, mature pseudocysts without necrotic debris, and we recommend this procedure only after a detailed assessment of the pseudocyst in a specialist hepatobiliary unit.
Population pharmacokinetics and haemodynamic effects of norepinephrine in hypotensive critically ill children
Authors: Oualha Mehdi , Tréluyer Jean‐Marc , Lesage Fabrice , de Saint Blanquat Laure , Dupic Laurent , Hubert Philippe , Spreux‐Varoquaux Odile , Urien Saïk 
Published: May 2014

AimThe aim of the study was to investigate the pharmacokinetics and pharmacodynamics of norepinephrine in hypotensive critically ill children, including associated variability factors.MethodsThis was a prospective study in an 18‐bed neonatal and paediatric intensive care unit. All children were aged less than 18 years, weighed more than 1500 g and required norepinephrine for systemic arterial hypotension. The pharmacokinetics and haemodynamic effects were described using the non‐linear mixed effect modelling software MONOLIX.ResultsNorepinephrine dosing infusions ranging from 0.05 to 2 μg kg−1 min−1 were administered to 38 children whose weight ranged from 2 to 85 kg. A one compartment open model with linear elimination adequately described the norepinephrine concentration–time courses. Bodyweight (BW) was the main covariate influencing norepinephrine clearance (CL) and endogenous norepinephrine production rate (q0) via an allometric relationship: CL(BWi) = θCL × (BWi)3/4 and q0(BWi) = θq0 × (BWi)3/4. The increase in mean arterial pressure (MAP) as a function of norepinephrine concentration was well described using an Emax model. The effects of post‐conceptional age (PCA) and number of organ dysfunctions were significant on basal MAP level (MAP0i = MAP0 × PCA/9i0.166) and on the maximal increase in MAP (32 mmHg and 12 mmHg for a number of organ dysfunctions ≤3 and ≥4, respectively).ConclusionThe pharmacokinetics and haemodynamic effects of norepinephrine in hypotensive critically ill children highlight the between‐subject variability which is related to the substantial role of age, BW and severity of illness. Taking into account these individual characteristics may help clinicians in determining an appropriate initial a priori dosing regimen.