bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resident‐immigrant dichotomy matters for classifying wetland site groups and metacommunities
Authors: Bried Jason T. , McIntyre Nancy E. , Dzialowski Andrew R. , Davis Craig A. 
Published: August 2015

Summary

The fact that species have resident (autochthonous) or immigrant (allochthonous) status at any given locality may have strong implications for ecological analysis.

We used wetlands and adult odonates as a model system to evaluate the resident‐immigrant dichotomy for two modes of community analysis: (1) grouping sites based on species compositional variation and (2) identifying metacommunity structure. We tested a hypothesis of gradient‐structured (non‐random) resident occurrence versus unstructured (random) immigrant occurrence in the metacommunity context and predicted the resident occurrence would more effectively partition community variation and produce stronger site groupings than total (resident + immigrant) occurrence.

Site group classification after fractioning out resident occurrence consistently and in some cases dramatically outperformed total occurrence. Resident damselflies produced the strongest classifications, which we attribute to greater dispersal limitation, environmental sorting or both.

As predicted only the resident occurrence led to identifiable metacommunity structures, primarily Clementsian‐style turnover. This suggests the resident occurrence is gradient‐driven with species responding similarly to abiotic filters, whereas immigrant occurrence is more opportunistic and random.

The resident‐immigrant dichotomy appears to have strong influence on quantitative classification of sites and metacommunities, and species composition of resident adult damselflies is potentially useful for differentiating and indicating site groups of non‐forested freshwater wetlands.
Phytoplankton lipid content influences freshwater lake methanogenesis
Authors: West William E. , McCarthy Shayna M. , Jones Stuart E. 
Published: August 2015

Summary

Rates of methanogenesis in freshwater sediments have been shown to increase with inputs of phytoplankton biomass. Although many studies have shown the importance of resource quality for decomposition, little is known of the importance of substrate quality on rates of methanogenesis.

Here, we studied the effects of lipid content and taxonomic affiliation of phytoplankton biomass on rates of methanogenesis in lake sediment slurries from five lakes differing in trophic status.

Substrate quantity had a positive effect on methanogenesis despite differing trophic status. Furthermore, we observed that phytoplankton biomass quality, in terms of lipid content, enhanced methanogenesis rates. However, rates of methanogenesis between lake sediments treated with Scenedemus obliquus or Microcystis aeruginosa did not differ when lipid content was held constant.

Phytoplankton lipid content has been shown to increase when nutrients are limiting, which may result in an increase in substrate quality for methanogenesis with eutrophication. However, our study revealed that responses of substrate quantity to nutrient enrichment likely outpace the effects of resource quality and may result in a net increase in CH4 emissions from eutrophied lakes. Interestingly, the resource quality feedback may at least partially reduce the potential effect of eutrophication on lake methanogenesis.
Mapping the spatial distribution of the biomass and filter‐feeding effect of invasive dreissenid mussels on the winter‐spring phytoplankton bloom in Lake Michigan
Authors: Rowe Mark D. , Obenour Daniel R. , Nalepa Thomas F. , Vanderploeg Henry A. , Yousef Foad , Kerfoot W. Charles 
Published: August 2015

Summary

The effects of the invasive bivalves Dreissena polymorpha (zebra mussel) and Dreissena rostriformis bugensis (quagga mussel) on aquatic ecosystems, including Lake Michigan, are a topic of current interest to scientists and resource managers. We hypothesised that the winter–spring phytoplankton bloom in Lake Michigan is reduced at locations where the fraction of the water column cleared per day by Dreissena filter feeding approached the net growth rate of phytoplankton, when the water column was not stratified. To test this hypothesis, we compared the spatial distribution of Dreissena filter‐feeding intensity (determined from geostatistical modelling) to the spatial distribution of chlorophyll (determined from satellite remote sensing).

To map the spatial distribution of Dreissena biomass and filter‐feeding intensity, we developed a geostatistical model based on point observations of mussel biomass measured in Lake Michigan in 1994/1995, 2000, 2005 and 2010. The model provided fine‐scale estimates of the spatial distribution of biomass for the survey years and provided estimates, with their uncertainty, of total biomass lakewide and within subregions. The approach outlined could be applied more generally to map the distribution of benthic biota in lakes from point observations.

Total biomass of Dreissena in Lake Michigan, estimated from the geostatistical model, increased significantly over each five‐year period. The total biomass in units of 106 kg ash‐free dry mass (AFDM) (with 90% confidence interval) was 6 (4–8) in 1994/1995, 18 (14–23) in 2000, 408 (338–485) in 2005 and 610 (547–680) in 2010. From 1994/1995 to 2005, increases were observed in all regions of the lake (northern, central and southern) and in all depth zones (<30, 30–50, 50–90 and >90). However, from 2005 to 2010, for depths of <50 m, biomass declined in the northern region, remained constant in the central region and increased in the southern region; biomass continued to increase in all three lake regions for depths >50 m.

The filter‐feeding intensity of Dreissena exceeded the benchmark spring phytoplankton growth rate of 0.06 day−1 in 2005 for depths <50 m (lakewide). In 2010, the filter‐feeding impact exceeded 0.06 day−1 within depths <90 m (lakewide), which greatly increased the spatial area affected relative to 2005. A regression analysis indicated a significant relationship between the reduction in satellite‐derived chlorophyll concentration (pre‐D. r. bugensis period to post‐D. r. bugensis period) and spatially co‐located filter‐feeding intensity (fraction of water column cleared per day) during periods when the water column was not stratified (December to April).
Alluvial ground water influences dissolved organic matter biogeochemistry of pools within intermittent dryland streams
Authors: Siebers Andre R. , Pettit Neil E. , Skrzypek Grzegorz , Fellman Jason B. , Dogramaci Shawan , Grierson Pauline F. 
Published: August 2015

Summary

The dissolved organic matter (DOM) biogeochemistry of intermittent rivers is affected by periods of disconnection and drying after cessation of surface flow, with a pronounced concentration of solutes as pools evaporate and contract. However, inputs of alluvial ground water to stream pools may offset the effects of evaporation and influence the quantity and composition of DOM.

We used δ18O and δ2H values of surface water and alluvial ground water (AW) together with DOM fluorescence excitation–emission spectroscopy to investigate changes in DOM biogeochemistry of pools from four intermittent streams in semi‐arid north‐west Australia. Our objective was to determine whether the fluorescence characteristics of DOM in pools are driven by their connectivity to alluvial ground water.

Pool water δ18O values ranged from −8 to 13.1 ‰ and showed progressive enrichment as pools became disconnected from AW and subsequently evaporated. Parallel factor analysis of DOM fluorescence revealed that DOM in pools was generally dominated by humic‐like components, with lesser contributions from tryptophan‐like and tyrosine‐like components.

DOC concentrations were higher in more evaporated pools. Humic‐like and tryptophan‐like DOM were also highest in pools isolated from AW, suggesting that inputs of AW had a dilution effect while also moderating evaporative concentration of solutes. In contrast, tyrosine‐like DOM was only weakly correlated with the hydrological status of pools.

The proportion that each component contributed to total DOM fluorescence remained mostly consistent across both AW‐connected and evaporating pools. However, some pools with AW throughflow had higher contributions from tyrosine‐like fluorescence and lower contributions from humic‐like fluorescence.

Disconnection from AW and subsequent evaporative concentration of solutes is an important control on DOM fluorescence characteristics in these intermittent streams. However, production and removal of DOM were only rarely influenced by AW connectivity, likely reflecting the high hydrological variability of intermittent rivers, even following cessation of surface flow.
The general dynamic model: towards a unified theory of island biogeography?
Authors: Borregaard Michael K. , Matthews Thomas J. , Whittaker Robert J. 
Published: August 2015

AbstractAimIsland biogeography focuses on understanding the processes that underlie a set of well‐described patterns on islands, but it lacks a unified theoretical framework for integrating these processes. The recently proposed general dynamic model (GDM) of oceanic island biogeography offers a step towards this goal. Here, we present an analysis of causality within the GDM and investigate its potential for the further development of island biogeographical theory. Further, we extend the GDM to include subduction‐based island arcs and continental fragment islands.LocationA conceptual analysis and a simulation of oceanic islands.MethodsWe describe the causal relationships between evolutionary and ecological processes implied by the GDM, implement them as a computer simulation and use this to simulate two alternative geological scenarios.ResultsThe dynamics of species richness and rates of evolutionary processes in simulations derived from the mechanistic assumptions of the GDM corresponded broadly to those initially suggested, with the exception of trends in extinction rates. Expanding the model to incorporate different scenarios of island ontogeny and isolation revealed a sensitivity of evolutionary dynamics to attributes of island geology.Main conclusionsWe argue that the GDM of oceanic island biogeography has the potential to provide a unified framework for island biogeography, integrating geological, ecological and evolutionary processes. Our simulations highlight how the geological dynamics of distinct island types are predicted to lead to markedly different evolutionary dynamics. This sets the stage for a more predictive theory incorporating the processes governing temporal dynamics of species diversity on islands.
Outcome of intravenous recombinant tissue plasminogen activator for acute ischemic stroke in patients aged over 80 years
Authors: Mione Gioia , Ducrocq Xavier , Thilly Nathalie , Lacour Jean‐Christophe , Vespignani Hervé , Richard Sébastien 
Published: August 2015

AimPractitioners are faced with a substantial challenge when considering recombinant tissue plasminogen activator (rt‐PA) therapy for older patients with ischemic stroke. Patients aged over 80 years suffer from the most severe cerebral infarcts. The benefit of rt‐PA treatment compared with single standard care only in stroke units remains to be clearly assessed.MethodsWe collected data from 321 patients aged over 80 years admitted for acute cerebral infarction to the stroke unit of Nancy University Hospital in France between 1 January 2009 and 31 December 2012. Patients were stratified into two groups: treated or not with rt‐PA. Baseline characteristics and outcome were collected and compared between both groups. Good outcome at 3 months was defined as modified Rankin Scale score ≤2.ResultsThe 55 patients treated with rt‐PA had a higher National Institute of Health Stroke Scale score on admission than those without (15 vs 5; P < 0.001). They were more likely to have intracranial haemorrhage (20 vs 5%; P < 0.001) without an increased mortality rate (28 vs 27%; P = 0.95). Multivariate analysis showed a more favorable outcome (odds ratio 7, 95% confidence interval 3–16.5; P < 0.001). Slightly higher percentages of patients with modified Rankin Scale ≤2 were found after intention‐to‐treat analysis (49 vs 45%) and after exclusion of patients with baseline modified Rankin Scale >2 (57 vs 54 %), but without reaching significance (P > 0.05).ConclusionsRt‐PA therapy would appear to improve prognosis in the elderly with ischemic stroke. This suggests that age alone should no longer be a barrier to rt‐PA therapy. Geriatr Gerontol Int 2016; 16: 843–849.
Sarcopenia prevalence and factors associated with sarcopenia in older people living in a nursing home in Ankara Turkey
Authors: Yalcin Ahmet , Aras Sevgi , Atmis Volkan , Cengiz Ozlem Karaarslan , Varli Murat , Cinar Esat , Atli Teslime 
Published: August 2015

AimSarcopenia is prevalent in older people, and is related to survival and disability. There are no data on sarcopenia evaluated according to European Working Group on Sarcopenia in Older People criteria for nursing home residents in Turkey. We aimed to evaluate the prevalence of sarcopenia according to European Working Group on Sarcopenia in Older People criteria and associated factors with sarcopenia among nursing home residents in Turkey.MethodsThe study cohort consisted of individuals aged over 65 years and living in the Seyranbağları Nursing Home and Rehabilitation Center in Ankara, Turkey. Besides demographic and medical data, Mini‐Mental State Examination, activities of daily living, Mini‐Nutritional Assessment, body mass index, calf circumference, gait speed and handgrip strength were also investigated. Muscle mass was evaluated by bioelectrical impedance analysis. Sarcopenia was diagnosed according to European Working Group on Sarcopenia in Older People criteria.ResultsA total of 141 older individuals were evaluated. Sarcopenia was found in 29% (n = 41) of the participants. Participants with sarcopenia were older and had low scores for activities of daily living, low body mass index, greater cognitive dysfunction, high malnutrition risk and low calf circumference. Body mass index and calf circumference were found to be associated with sarcopenia in multivariate logistic regression analysis.ConclusionsAlmost one‐third of older nursing home residents were diagnosed with sarcopenia according to European Working Group on Sarcopenia in Older People criteria in this study in Turkey. Calf circumference and body mass index were associated with increased risk of sarcopenia among nursing home residents. This is the first study evaluating sarcopenia using European Working Group on Sarcopenia in Older People criteria in Turkey. Geriatr Gerontol Int 2016; 16: 903–910.
Influence of comorbidities on the efficacy of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease
Authors: Higashimoto Yuji , Yamagata Toshiyuki , Maeda Kazushige , Honda Noritsugu , Sano Akiko , Nishiyama Osamu , Sano Hiroyuki , Iwanaga Takashi , Chiba Yasutaka , Fukuda Kanji , Tohda Yuji 
Published: August 2015

AimTo evaluate the influence of comorbidities and aging on pulmonary rehabilitation (PR) efficacy in patients with chronic obstructive pulmonary disease (COPD).MethodsThis was a retrospective cohort study of patients with COPD attending an outpatient PR program. Comorbidity information was collected with the Charlson Index, BODE index and COPD‐specific comorbidity test, and also included other common conditions not included in these indexes. The efficacy of PR was defined as a 54‐m increase in 6‐min walk distance or a four‐point decrease in St. George's Respiratory Questionnaire score. Patients were divided into two age groups according to the median age of 72 years.ResultsA total of 21 of 52 patients (40%) showed a clinically significant benefit by the 6‐min walk distance, and 29 patients (55.8%) by the St. George's Respiratory Questionnaire score. PR efficacy was not different between the elderly group and the younger group by either parameter. A total of 98% of the patients had at least one chronic comorbidity. Hypertension was the most frequently reported comorbidity (28.5%). Higher body mass index, Hospital Anxiety and Depression Scale anxiety score and St. George's Respiratory Questionnaire total score were associated with a good response to PR by the 6‐min walk distance. None of the individual comorbidities or indexes were correlated with the efficacy of PR. Multiple logistic regression analysis showed that body mass index was independently associated with the response to PR.ConclusionsPR is equally effective in elderly and younger patients with COPD, with efficacy influenced by body mass index and anxiety. Geriatr Gerontol Int 2016; 16: 934–941.
High prevalence of subclinical hypothyroidism and nodular thyroid disease in patients on hemodialysis
Authors: Da Costa Ana Beatriz B.A. , Pellizzari Caio , Carvalho Gisah A. , Sant'Anna Beatriz C. , Montenegro Rafaela L. , Zammar Filho Roberto G. , Mesa Junior Cleo O. , Hauck Prante Patrícia R. , Olandoski Marcia , Carvalho Mauricio 
Published: August 2015

AbstractChronic kidney disease has been known to affect thyroid hormone metabolism. Low serum levels of T3 and T4 are the most remarkable laboratorial findings. A high incidence of goiter and nodules on thyroid ultrasonography has been reported in patients with end‐stage renal disease (ESRD). Our objective is to evaluate the prevalence of laboratorial and morphologic alterations in the thyroid gland in a cohort of patients with ESRD on hemodialysis (HD). Sixty‐one patients with ESRD on HD were selected and compared with 43 healthy subjects matched by age, gender, and weight. Patients were submitted to thyroid ultrasonography. T3, free T4 (FT4), thyroid‐stimulating hormone, antithyroglobulin, and antithyroperoxidase antibodies were measured. The mean age of patients with ESRD was 47.4 ± 12.3 and 61% were women. ESRD was mainly caused by hypertensive nephrosclerosis and diabetic nephropathy. Mean thyroid volume, as determined by ultrasonography, was similar in both groups. Patients with ESRD had more hypoechoic nodules when compared with the control group (24.1% vs. 7.9%, P = 0.056). Mean serum FT4 and T3 levels were significantly lower in patients with ESRD, and subclinical hypothyroidism was more prevalent in patients with ESRD (21.82% vs. 7.14% control group, P = 0.04). Titers of antithyroid antibodies were similar in both groups. ESRD was associated with a higher prevalence of subclinical hypothyroidism and lower levels of T3 and FT4. Almost a quarter of patients showed thyroid nodules >10 mm. Periodic ultrasound evaluation and assessment of thyroid function are recommended in patients with ESRD on HD.
Malva verticillata seed extracts upregulate the Wnt pathway in human dermal papilla cells
Authors: Lee E. Y. , Choi E.‐J. , Kim J. A. , Hwang Y. L. , Kim C.‐D. , Lee M. H. , Roh S. S. , Kim Y. H. , Han I. , Kang S. 
Published: August 2015

SynopsisObjectiveMesenchymal–epithelial interactions are important in controlling hair growth and the hair cycle. The β‐catenin pathway of dermal papilla cells (DPCs) plays a pivotal role in morphogenesis and normal regeneration of hair follicles. Deletion of β‐catenin in the dermal papilla reduces proliferation of the hair follicle progenitor cells that generate the hair shaft and induces an early onset of the catagen phase. In this study, a modulator of the Wnt/β‐catenin activity was studied in oriental herb extracts on cultured human DPCs.MethodsThe effect of Malva verticillata (M. verticillata) seeds on human DPCs was investigated by a Wnt/β‐catenin reporter activity assay system (β‐catenin–TCF/LEF reporter gene) and cell proliferation analysis. The synthesis of the factors related to hair growth and cycling was measured at both the mRNA and the protein level by semi‐quantitative PCR and Western blot analysis, respectively.ResultsAn extract from M. verticillata seeds increased Wnt reporter activity in a concentration‐dependent manner and also led to increased β‐catenin levels in cultured human DPCs. Myristoleic acid, identified as an effective compound of M. verticillata seeds, stimulated the proliferation of DPCs in a dose‐dependent manner and increased transcription levels of the downstream targets: IGF‐1, KGF, VEGF and HGF. Myristoleic acid also enhanced the phosphorylation of MAPKs (Akt and p38).ConclusionOverall, the data suggest that this extract of M. verticillata seeds could be a good candidate for treating hair loss by modulating the Wnt/β‐catenin pathway in DPCs.
Optimum aqueous extraction conditions for preparation of a phenolic‐enriched Davidson's plum (Davidsonia pruriensF. Muell) extract
Authors: Chuen Tiffany L.K. , Vuong Quan V. , Hirun Sathira , Bowyer Michael C. , Goldsmith Chloe D. , Scarlett Christopher J. 
Published: August 2015

SummaryThis study aimed to optimise aqueous extraction conditions for total phenolic compounds (TPC) from Davidson's plum (Davidsonia pruriens F. Muell) and to assess the physicochemical and antioxidant properties of the phenolic‐enriched extract. The results showed that temperature, time and ratio significantly affected the extraction of TPC. Optimization of extraction conditions was performed using response surface methodology (RSM) utilising a Box–Behnken design. Optimal extraction conditions were determined to be temperature: 90 °C, extraction time: 30 min and solvent to mass ratio: 20:1 mL g−1. The extracted solid obtained under these conditions had low‐moisture content, high water solubility and contained 45 mg GAE g−1 of TPC, 22 mg RUE g−1 of flavonoids, 3.2 mg CAE g−1 of proanthocyanidins, 2 mg CGE g−1 of anthocyanidins and 56 mg ACE g−1 vitamin C. The extract possessed potent antioxidant capacity, but was comparatively lower than those of vitamin E and BHT. Thus, Davidson's plum should be further investigated for its potential health promoting benefits and utilisation in the nutraceutical and food industries.
Association between abdominal fat distribution, adipocytokines and metabolic alterations in obese low‐birth‐weight children
Authors: Domínguez Hernández C. , Klünder Klünder M. , Huang F. , Flores Armas E. M. , Velázquez‐López L. , Medina‐Bravo P. 
Published: August 2015

SummaryBackgroundIn addition to obesity, low birth weight (LBW) has been proposed as another independent risk factor associated with cardiovascular disease and type 2 diabetes mellitus.ObjectiveThis study aimed to evaluate the influence of birth weight on abdominal fat distribution, adipocytokine levels and associated metabolic alterations in obese children.MethodsA cross‐sectional study was conducted in 92 children. Children were divided into three groups according to their body mass index and birth weight. Glucose and insulin (0 and 120 min), lipid profile and adipocytokines were measured. Abdominal fat distribution was assessed by magnetic resonance imaging.ResultsObese LBW children had higher fasting glucose (P = 0.054) and insulin (P < 0.001), and 120 min glucose (P < 0.001) and insulin levels (P < 0.001), such as increased HOMA‐IR (homeostasis model assessment of insulin resistance index) (P < 0.001). Obesity and LBW were associated with lower concentrations of high molecular weight (HMW) adiponectin (−2.38 [IC 95% −4.27; −0.42, P = 0.018]) and higher subcutaneous adipose tissue (SAT) (28.05 [IC 95% 0.40; 55.7, P = 0.047]) compared with NBW obese children, independent of age or sex.ConclusionsLBW in obese children is associated with lower HMW adiponectin, increased insulin resistance and greater SAT.