bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biodiversity surrogate groups and conservation priority areas: birds of the Brazilian Cerrado
Authors: Pinto Míriam Plaza , Diniz‐Filho José Alexandre Felizola , Bini Luis Mauricio , Blamires Daniel , Rangel Thiago Fernando L. V. B. 
Published: February 2009

ABSTRACTThe choice of surrogates of biodiversity is an important aspect in conservation biology. The quantification of the coincidence in the spatial patterns of species richness and rarity between different groups and the vulnerability of groups are different approaches frequently considered to accomplish this task. However, a more appropriate approach is to verify the efficiency of priority networks selected using information from one group of organisms to capture the biodiversity of other groups. Using a deconstructive approach, the main purposes of this study were to evaluate the performance of some orders and families of birds in the Cerrado biome (a savanna‐like biome) as surrogates of other bird groups, in a pairwise analysis, and to investigate the characteristics of these groups that predict the efficiency in representation of other groups. We used biogeographical data on bird orders or families with more than 10 species that occur in the Brazilian Cerrado. The best surrogate group was the Thamnophilidae. Moreover, this group is not the most specious, favouring further survey efforts that are necessary to verify the conservation value of areas at suitable scales. The majority of the species from this family are dependent on forest habitats, one of the characteristics that most influenced representativeness level, probably due to the spatial distribution of these habitats throughout the Brazilian Cerrado. Beta diversity patterns of the different groups also affected representativeness, and our analyses showed that the networks selected by a surrogate group will be more effective in the representation of other groups of species if their patterns of beta diversity (not richness) are correlated.
Testing predictions of beetle community patterns derived empirically using remote sensing
Authors: Lassau Scott A. , Hochuli Dieter F. 
Published: February 2009

ABSTRACTPatterns generated from ecological surveys are rarely tested in similar habitats to assess the accuracy of predictions. Testing empirically derived predictions provides a strong tool for establishing the consistency of general patterns in ecology. We test the consistency of beetle community associations with habitat complexity in open canopy forests and make both community and morphospecies‐level comparisons with results from a previous study. We use Normalized Difference Vegetation Indices (NDVIs) from remote sensing as a surrogate for habitat complexity. The positive relationships between NDVIs and site‐based beetle species richness and abundance were consistent in open canopy forests both south and north of Sydney, Australia. NDVIs were also useful for predicting differences in beetle composition in open canopy forests. Taxon‐specific responses to NDVI differences in ‘southern forests’ were very similar to responses in ‘northern forests’, most likely reflecting beetle trophic roles. This study shows that NDVIs can be used as rapid biodiversity indicators, when integrated with identified faunal responses to vegetation structure, provided that the lower vegetation strata may be measured by remote sensing.
How far and how fast do bryophytes travel at the landscape scale?
Authors: Hutsemekers V. , Dopagne C. , Vanderpoorten A. 
Published: February 2009

ABSTRACTDispersal ability is a factor of prime importance to explain biotic distributions. Yet, it is extremely difficult to measure directly. In this study, we take advantage of the natural experimental design of slag heap colonization in Belgium to document the timing and range of dispersal of bryophytes at the landscape scale. On the basis of a species atlas with a 4 × 4 km grid, the minimum distance separating species found on 52 slag heaps from potential source populations was determined. Minimum dispersal rates were inferred by coupling the information on minimum distance between slag heap and source populations with time since colonization. The number of species per slag heap is significantly correlated with time since colonization and area size. The frequency distribution of the longest dispersal events is highly skewed, with 44% of the species recruited within the nearest 6 km. In the remaining 56% of the species, recruitments from source populations located within a range of at least 6–86 km occurred within a period of less than 50 years. The majority of the species that are not recruited within the nearest vicinity of the slag heaps, including rare species at the regional scale, occur on slag heaps that have been colonized for 25–50 years. Most recently colonized slag heaps are indeed characterized by ‘fugitive’, weedy species, whereas slag heaps that have been colonized for > 50 years tend to accumulate perennial species with a ‘stayer’ life strategy. These observations suggest that rare species may display the dispersal ability to travel across the landscape, but are subsequently limited by their ability to establish a viable community because of more competitive neighbours. Rare species therefore tend to accumulate at intermediate colonization stages, which represent a trade‐off between an increasing probability of colonization with time and a decreasing probability of establishment due to competition.
Solving the maximum representation problem to prioritize areas for the conservation of terrestrial mammals at risk in Oaxaca
Authors: Illoldi‐Rangel Patricia , Fuller Trevon , Linaje Miguel , Pappas Christopher , Sánchez‐Cordero Víctor , Sarkar Sahotra 
Published: February 2009

ABSTRACTOaxaca, located in south‐west México within the Mesoamerican biodiversity hotspot, holds exceptionally high biodiversity for several taxa, including mammals. It has four decreed natural protected areas (NPAs) covering 5% of its total area, but only three of these, covering only 0.2% of the area, are strictly protected as National Parks. The current study develops ecological niche models for 183 terrestrial mammals for use as biodiversity surrogates in a systematic conservation planning exercise. Forty‐five of these species were selected on the basis of their being either endangered or threatened or otherwise listed under the Mexican Red List or because they were endemic to either Oaxaca or to Mexico. The niche models were constructed with a machine‐learning algorithm (GARP, Genetic Algorithm for Rule‐Set Prediction) and refined by restricting each model to sites with suitable vegetation and habitat patches contiguous with known occurrences of the species. If the entire predicted geographical distribution of each of the 45 species listed above is put under protection, the entire state of Oaxaca gets included. Therefore, we imposed different constraints on the maximum area that can be put under protection (5–30% of the area of Oaxaca) and selected nominal conservation area networks based on different percentage representation targets for the species’ modelled distributions based on their conservation status (10–100%). The area selection utilized a rarity‐ and complementarity‐based algorithm (in the ResNet software package). The goal was to have as many as possible of the 45 species at risk meet their specified representation targets in the budgeted area. The methods developed here combine ecological niche modelling and area prioritization algorithms for integrated conservation planning in a protocol that is suitable for other highly biodiverse regions.
Extinction patterns in the avifauna of the Hawaiian islands
Authors: Boyer Alison G. 
Published: February 2009

ABSTRACTThrough the continuing accumulation of fossil evidence, it is clear that the avifauna of the Hawaiian Islands underwent a large‐scale extinction event around the time of Polynesian arrival. A second wave of extinctions since European colonization has further altered this unique avifauna. Here I present the first systematic analysis of the factors characterizing the species that went extinct in each time period and those that survived in order to provide a clearer picture of the possible causal mechanisms. These analyses were based on mean body size, dietary and ecological information and phylogenetic lineage of all known indigenous, non‐migratory land and freshwater bird species of the five largest Hawaiian Islands. Extinct species were divided into ‘prehistoric’ and ‘historic’ extinction categories based on the timing of their last occurrence. A model of fossil preservation bias was also incorporated. I used regression trees to predict probability of prehistoric and historic extinction based on ecological variables. Prehistoric extinctions showed a strong bias toward larger body sizes and flightless, ground‐nesting species, even after accounting for preservation bias. Many small, specialized species, mostly granivores and frugivores, also disappeared, implicating a wide suite of human impacts including destruction of dry forest habitat. In contrast, the highest extinction rates in the historic period were in medium‐sized nectarivorous and insectivorous species. These differences result from different causal mechanisms underlying the two waves of extinction.
Common species have lower taxonomic diversity Evidence from the urban floras of Brussels and Rome
Authors: Ricotta Carlo , Godefroid Sandrine , Celesti‐Grapow Laura 
Published: February 2009

ABSTRACTThe species pool hypothesis claims that the large‐scale regional species pool is the chief parameter in determining small‐scale species richness through filtering of species that can persist within a community on the basis of their tolerance of the abiotic environment. Accordingly, different environmental conditions give rise to different species assemblages. From a taxonomic perspective, under the assumption of trait conservatism, co‐occurring species that experience similar environmental conditions are likely to be more taxonomically similar than ecologically distant species. The next step consists in understanding how commonness and rarity of individual species produce the observed taxonomic diversity. In this paper, the importance of environmental filtering in regulating the taxonomic structure of rare and common plant species in the urban floras of Brussels (Belgium) and Rome (Italy) is tested. First, we computed the taxonomic diversity of the rare and common species of Brussels and Rome based on the branching topology of the Linnaean taxonomic trees. Next, using a randomization procedure, we determined whether the taxonomic diversity of the rare species was significantly higher than the diversity of the common species. Results show that, for both urban floras, common species that shape the community matrix and experience similar environmental conditions have a taxonomic diversity that is significantly lower than that of the rare species that represent a relatively incidental set of species of more ‘disperse’ origin. Finally, from a conservation/management perspective our results imply that, given their high taxonomic heterogeneity, the protection of rare species is a central issue for preserving high levels of diversity in urban areas.
Overstorey tree species regulate colonization by native and exotic plants: a source of positive relationships between understorey diversity and invasibility
Authors: Knight Kathleen S. , Oleksyn Jacek , Jagodzinski Andrzej M. , Reich Peter B. , Kasprowicz Marek 
Published: February 2009

ABSTRACTThe North American woody species, Prunus serotina Ehrh., is an aggressive invader of forest understories in Europe. To better understand the plant invasion process, we assessed understorey plants and Prunus serotina seedlings that have colonized a 35‐year‐old replicated common‐garden experiment of 14 tree species in south‐western Poland. The density and size of established (> 1 year old) P. serotina seedlings varied among overstorey species and were related to variation in light availability and attributes of the understorey layer. In a multiple regression analysis, the density of established P. serotina seedlings was positively correlated with light availability and understorey species richness and negatively correlated with understorey species cover. These results suggest that woody invader success is adversely affected by overstorey shading and understorey competition for resources. Simultaneously, however, invader success may generally be positively associated with understorey species richness because both native and invasive plant colonization respond similarly to environmental conditions, including those influenced by overstorey tree species. Identification of characteristics of forests that increase their susceptibility to invasion may allow managers to target efforts to detect invasives and to restore forests to states that may be less invasible.
Marine biogeographical disjunction in temperate Australia: historical landbridge, contemporary currents, or both?
Authors: Waters Jonathan M. 
Published: February 2009

ABSTRACTMarine biogeographers have long recognized broad east–west differentiation of marine communities across southern Australia, but few studies have explicitly assessed the site of disjunction or the factors potentially underlying this biodiversity. A recent, detailed phylogeographical and distributional study of the dispersive gastropod genus Nerita revealed an abrupt shift in species abundance across mainland Australia, apparently correlated with the site of an historical vicariant barrier: the Bassian Isthmus. In the current study I provide an independent assessment of this vicariant hypothesis by morphologically analysing over 3000 intertidal Nerita specimens from eight coastal sites around Tasmania. Consistent with the Bassian Isthmus hypothesis, the study reveals a dramatic east–west disjunction across north‐east Tasmania. A survey of marine biogeographical literature reveals several additional examples supporting the east–west species turnover detected in Nerita. I discuss the role of contemporary oceanographic factors in preserving the biogeographical signature of marine vicariance, even in highly dispersive taxa. Based on recent marine connectivity data, the east–west disjunction in Nerita taxa can be interpreted as an historic vicariant pattern perpetuated by contemporary oceanographic conditions. The results of this study emphasize the potential importance of considering relative abundance data – rather than just species range data – in marine biogeographical analyses. As the observed disjunction is likely to have broad implications for Australia's marine biodiversity, it is imperative that conservation biologists incorporate such data in the design of marine protected areas.
Serum creatinine and bilirubin predict renal failure and mortality in patients with spontaneous bacterial peritonitis: a retrospective study
Authors: Terg Rubén , Gadano Adrian , Cartier Mariano , Casciato Paola , Lucero Romina , Muñoz Alberto , Romero Gustavo , Levi Diana , Terg Gonzalo , Miguez Carlos , Abecasis Raquel 
Published: February 2009

AbstractBackground: Patients with spontaneous bacterial peritonitis (SBP) are at a high risk for renal failure and death despite successful treatment of infection. Intravenous (IV) albumin administration combined with antibiotic treatment has been shown to significantly decrease these risks. Clinical evidence is lacking on which patients are appropriate candidates for albumin treatment.Aim: To retrospectively analyse the usefulness of serum creatinine and bilirubin levels in predicting renal failure and mortality of patients hospitalized for SBP.Methods: Between March 1995 and September 1998, 127 cirrhotic patients with SBP who had not received plasma expansion were evaluated. Eighty‐one patients (64%) were classified as having a high risk for renal failure and mortality (serum bilirubin >4 mg/dl or serum creatinine >1 mg/dl) and 46 (36%) as having a low risk.Results: At admission, 36.3% of all patients presented renal failure. Mortality during their hospitalization was 23% among those with a high risk and 6.5% among those with a low risk (P=0.01). Renal failure occurred in 23% of the high‐risk patients, compared with 2.6% of the low‐risk patients (P=0.006). The presence of hyponatraemia was significantly associated with higher mortality and renal failure in the high‐risk group.Conclusions: Our retrospective review of patients with SBP suggests that serum bilirubin levels >4 mg and serum creatinine levels >1 mg/dl at the time of diagnosis represent significant risk factors for the clinical outcomes of patients with SBP. Patients without these risk factors may have a very low likelihood of death or renal failure.
CHUKCHIA PEDICELLATA GEN. ET SP. NOV. AND C. ENDOPHYTICA NOV. COMB., ARCTIC ENDEMIC BROWN ALGAE (PHAEOPHYCEAE)1
Authors: Wilce Robert T. , Pedersen P. M. , Sekida S. 
Published: February 2009

Study of the north Alaskan brown algal epiphyte Chukchia pedicellata sp. nov. suggests an apparently close relationship to Phaeostroma. Phaeostroma endophyticum S. Lund from east Greenland, Bylot Island, Nunavut, Canada, shows generic identity with Chukchia and specific differences from C. pedicellata. Comparison of C. pedicellata and P. pustulosum Kuck. (the type species of Phaeostroma) shows morphological, cytological, reproductive, and distributional differences. We recognize novelty of C. pedicellata and necessity to broaden the species description of P. endophyticum, which becomes Chukchia endophytica. C. endophytica is distinguished by its dimorphic vegetative habit, its large plurilocular sporangia, and the putative ability of the sporangia to digest host tissue to accommodate development within the host. Absence of pyrenoids and novel plurilocular sporangia in both species suggests that they are not members of the Ectocarpales, sensu lato.
Forecasting Models of Emergency Department Crowding
Authors: Schweigler Lisa M. , Desmond Jeffrey S. , McCarthy Melissa L. , Bukowski Kyle J. , Ionides Edward L. , Younger John G. 
Published: February 2009

AbstractObjectives:  The authors investigated whether models using time series methods can generate accurate short‐term forecasts of emergency department (ED) bed occupancy, using traditional historical averages models as comparison.Methods:  From July 2005 through June 2006, retrospective hourly ED bed occupancy values were collected from three tertiary care hospitals. Three models of ED bed occupancy were developed for each site: 1) hourly historical average, 2) seasonal autoregressive integrated moving average (ARIMA), and 3) sinusoidal with an autoregression (AR)‐structured error term. Goodness of fits were compared using log likelihood and Akaike’s Information Criterion (AIC). The accuracies of 4‐ and 12‐hour forecasts were evaluated by comparing model forecasts to actual observed bed occupancy with root mean square (RMS) error. Sensitivity of prediction errors to model training time was evaluated, as well.Results:  The seasonal ARIMA outperformed the historical average in complexity adjusted goodness of fit (AIC). Both AR‐based models had significantly better forecast accuracy for the 4‐ and the 12‐hour forecasts of ED bed occupancy (analysis of variance [ANOVA] p < 0.01), compared to the historical average. The AR‐based models did not differ significantly from each other in their performance. Model prediction errors did not show appreciable sensitivity to model training times greater than 7 days.Conclusions:  Both a sinusoidal model with AR‐structured error term and a seasonal ARIMA model were found to robustly forecast ED bed occupancy 4 and 12 hours in advance at three different EDs, without needing data input beyond bed occupancy in the preceding hours.
Vulnerability of hippocampal GABA‐ergic interneurons to kainate‐induced excitotoxic injury during old age
Authors: Shetty Ashok K. , Hattiangady Bharathi , Rao Muddanna S. 
Published: February 2009

AbstractHippocampal inhibitory interneurons expressing glutamate decarboxylase‐67 (GAD‐67) considerably decline in number during old age. Studies in young adult animals further suggest that hippocampal GAD‐67+ interneuron population is highly vulnerable to excitotoxic injury. However, the relative susceptibility of residual GAD‐67+ interneurons in the aged hippocampus to excitotoxic injury is unknown. To elucidate this, using both adult and aged F344 rats, we performed stereological counting of GAD‐67+ interneurons in different layers of the dentate gyrus and CA1 & CA3 sub‐fields, at 3 months post‐excitotoxic hippocampal injury inflicted through an intracerebroventricular administration of kainic acid (KA). Substantial reductions of GAD‐67+ interneurons were found in all hippocampal layers and sub‐fields after KA‐induced injury in adult animals. Contrastingly, there was no significant change in GAD‐67+ interneuron population in any of the hippocampal layers and sub‐fields following similar injury in aged animals. Furthermore, the stability of GAD‐67+ interneurons in aged rats after KA was not attributable to milder injury, as the overall extent of KA‐induced hippocampal principal neuron loss was comparable between adult and aged rats. Interestingly, because of the age‐related disparity in vulnerability of interneurons to injury, the surviving GAD‐67+ interneuron population in the injured aged hippocampus remained comparable to that observed in the injured adult hippocampus despite enduring significant reductions in interneuron number with aging. Thus, unlike in the adult hippocampus, an excitotoxic injury to the aged hippocampus does not result in significantly decreased numbers of GAD‐67+ interneurons. Persistence of GAD‐67+ interneuron population in the injured aged hippocampus likely reflects an age‐related change in the response of GAD‐67+ interneurons to excitotoxic hippocampal injury. These results have implications towards understanding mechanisms underlying the evolution of initial precipitating injury into temporal lobe epilepsy in the elderly population.
PKR, a cognitive decline biomarker, can regulate translation via two consecutive molecular targets p53 and Redd1 in lymphocytes of AD patients
Authors: Damjanac Milena , Page Guylène , Ragot Stéphanie , Laborie Guillaume , Gil Roger , Hugon Jacques , Paccalin Marc 
Published: February 2009

AbstractIn Alzheimer’s disease (AD), the control of translation is dysregulated, precisely, two opposite pathways: double‐stranded RNA‐dependent protein kinase (PKR) is up‐regulated and mammalian target of rapamycin (mTOR) is down‐regulated. These biochemical alterations were found at the periphery in lymphocytes of AD patients and were significantly correlated with cognitive and memory test scores. However, the molecular crosslink between these two opposite signalling pathways remains unknown. The tumour suppressor p53 and Redd1 (regulated in development and DNA damage response) could be two downstream targets of active PKR to explain the breakdown of translation in AD patients. In this study, the protein and gene levels of p53 and Redd1 were assayed in lymphocytes of AD patients and in age‐matched controls by Western blotting and RT‐PCR. Furthermore, correlations were analysed with both the level of active PKR and the Mini Mental State Examination score (MMSE). The results show that the gene and protein levels of p53 and Redd1 were significantly increased about 1.5‐fold for both gene and Redd1 protein and 2.3‐fold for active p53 in AD lymphocytes compared to age‐matched controls. Furthermore, statistical correlations between proteins and genes suggest that active PKR could phosphorylate p53 which could induce the transcription of Redd1 gene. No correlations were found between MMSE scores and levels of p53 or Redd1, contrary to active PKR levels. PKR represents a cognitive decline biomarker able to dysregulate translation via two consecutive targets p53 and Redd1 in AD lymphocytes.