bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of fertilisation and irrigation on ‘foliar afterlife’ in alpine tundra
Authors: Soudzilovskaia Nadejda A. , Onipchenko Vladimir G. , Cornelissen Johannes H.C. , Aerts Rien 
Published: February 2009

AbstractQuestion:How do increases in soil nutrient and water availability alter the nutrient fluxes through the resorption and litter decomposition pathways and how do they affect litter nutrient pools in a low‐productive alpine tundra ecosystem?Location:An alpine lichen‐rich tundra on Mt. Malaya Khati‐para in the NW Caucasus, Russia (43°27’ N, 41°42’ E; altitude 2800 m a.s.l.).Methods:We conducted a 4‐year fertilisation (N, P, N+P, lime) and irrigation experiment, and analysed the responses of nutrient resorption from senescing leaves, leaf litter quality and decomposability of six pre‐dominant vascular plant species, total plant community litter production and litter (nutrient) accumulation.Results:Vascular plant litter [N] and [P] increased 1.5 and 10 fold in response to N and P additions, due to increased concentrations of the nutrients in fresh leaves and unchanged or reduced resorption efficiency. Litter decomposability was not affected by nutrient amendments. Fertilisation enhanced litter production (180%; N+P treatment) and litter accumulation (80%; N+P), owing to tremendously increased production and low decomposability of graminoids. Together with increased litter [N] and [P] this led to great increases in total litter nutrient pools.Conclusions:Due to increased production of graminoids, nutrients added to the alpine tundra soil were mostly immobilised in recalcitrant, nutrient‐rich litter. This suggests that changing species composition in low productive ecosystems may act as an internal buffer mechanism, which under increased soil nutrient availability prevents the community from rapidly acquiring features typical of a high productive ecosystem such as high decomposability and high nutrient availability.
Measuring beta‐diversity from taxonomic similarity
Authors: Bacaro Giovanni , Ricotta Carlo , Mazzoleni Stefano 
Published: February 2009

AbstractQuestion: The utility of beta (β‐) diversity measures that incorporate information about the degree of taxonomic (dis)similarity between species plots is becoming increasingly recognized. In this framework, the question for this study is: can we define an ecologically meaningful index of β‐diversity that, besides indicating simple species turnover, is able to account for taxonomic similarity amongst species in plots?Methods: First, the properties of existing measures of taxonomic similarity measures are briefly reviewed. Next, a new measure of plot‐to‐plot taxonomic similarity is presented that is based on the maximal common subgraph of two taxonomic trees. The proposed measure is computed from species presences and absences and include information about the degree of higher‐level taxonomic similarity between species plots. The performance of the proposed measure with respect to existing coefficients of taxonomic similarity and the coefficient of Jaccard is discussed using a small data set of heath plant communities. Finally, a method to quantify β‐diversity from taxonomic dissimilarities is discussed.Results: The proposed measure of taxonomic β‐diversity incorporates not only species richness, but also information about the degree of higher‐order taxonomic structure between species plots. In this view, it comes closer to a modern notion of biological diversity than more traditional measures of β‐di‐versity. From regression analysis between the new coefficient and existing measures of taxonomic similarity it is shown that there is an evident nonlinearity between the coefficients. This nonlinearity demonstrates that the new coefficient measures similarity in a conceptually different way from previous indices. Also, in good agreement with the findings of previous authors, the regression between the new index and the Jaccard coefficient of similarity shows that more than 80% of the variance of the former is explained by the community structure at the species level, while only the residual variance is explained by differences in the higher‐order taxonomic structure of the species plots. This means that a genuine taxonomic approach to the quantification of plot‐to‐plot similarity is only needed if we are interested in the residual system's variation that is related to the higher‐order taxonomic structure of a pair of species plots.
Post‐dispersal granivory in a tall‐tussock grassland: A positive feedback mechanism of dominance?
Authors: Murillo Natalia , Laterra Pedro , Monterubbianesi Gloria 
Published: February 2009

AbstractQuestions: Is post‐dispersal seed predation a factor contributing to a positive feedback mechanism for dominance of tall‐tussock grasslands? Do seeds dispersed into neighbouring microhabitats of contrasting dominance differ in their probabilities of being predated? Does predation rate vary among predator groups? Do seed eaters selectively forage among the available seeds?Location: The southern and flooding sub‐regions of the Argentinian Pampas.Methods: We examined seed predation by vertebrate and invertebrate predators within two microhabitats of grassland mosaics (highly dominated tall‐grass patches vs. scarcely dominated short‐grass matrix) for different seed species in semi‐natural grasslands. Proportion of seeds eaten by different predator groups was estimated through exclusion experiments and analysed using ANOVA for split‐split‐plot designs. Experiments were performed during the autumn of two consecutive years in both Pampa sub‐regions.Results: Removal of seeds after a five day trial was two to four times higher in the tall‐grass patches than in the short‐grass matrix. During the same period, vertebrate predation was six times higher than invertebrate predation in the tall‐grass phase of the Southern Pampa, but it did not differ in the short‐grass matrix. Relative predation among phases showed the same pattern in the Hooding Pampa, where preferences by seed species also varied according to phase.Conclusions: The highest predation intensity shown by vertebrates in the tall‐grass patches indicates that they are the main seed predators in these systems, possibly because this microhabitat grants them refuge against carnivorous predators. This could significantly reduce the available seeds for recruitment of subordinate species after different disturbance events (fires, trampling by large herbivores, burrowing), representing an active filter to the floristic composition of the patch and contributing with other mechanisms to the dominance of tall‐grass species.
Woody vegetation of a mosaic of protected areas adjacent to the Kruger National Park, South Africa
Authors: Peel M.J.S. , Kruger J.M. , MacFadyen S. 
Published: February 2009

AbstractQuestion: How is pattern detected and spatial scale defined in a manner that is meaningful to management?Location: Protected areas to the west of the Kruger National Park, South Africa.Methods: A Two‐Way Indicator Species Analysis (TWIN‐SPAN) based on composition and structure was applied to woody survey data. The resulting TWINSPAN classes for individual monitoring sites were used in a supervised classification of Landsat ETM+ imagery across the study area. The training sample's co‐ordinates were fed into a GIS and the resulting TWINSPAN point‐feature shape file was processed using a 1 km theme‐buffer function.Results: The supervised classification using the theme‐buffer signatures yielded a satisfactory overall accuracy (κ= 0.75; r2= 0.80; p= 0.05) using a test sample compiled by reserve wardens throughout the study area. The derived vegetation map was smoothed using a majority filter and after on‐screen digitizing a small gabbro intrusion, it was accepted as the best representation of the woody vegetation of the study area at a scale of 1:250 000. Seven plant communities were identified in the current study and satisfactorily accommodated within various topographical units of four extrapolated Landscapes of the Kruger National Park.Conclusions: Vegetation patterns are described of the areas under conservation management to the west of the KNP at a spatial scale that allows for the meaningful examination and comparison of the structure, functioning, and ultimately effective management, of these savannas. This contribution thus links to the co‐ordinated effort extending into the Trans‐Frontier National Park in Mocambique. A key objective is to better understand the functioning of these savanna systems for effective management and we discuss some of the key ecological issues within the plant communities of each landscape. The latter illustrate the usefulness of the technique in practice.
Small gap dynamics in the southern boreal forest of eastern Canada: Do canopy gaps influence stand development?
Authors: de Römer André H. , Kneeshaw Daniel D. , Bergeron Yves 
Published: February 2009

AbstractQuestion: To what extent do small‐scale disturbances in the forest canopy, created by natural disturbance agents, affect stand development? Doubts exist as to whether small canopy openings have any real effect on the understory tree recruitment, especially in boreal forests.Location: Conifer and mixed stands in the Gaspesian region in eastern Québec. The main natural disturbance agents are recurring outbreaks of Choristoneura fumiferana (eastern spruce budworm) and winds.Methods: Linear transects in 27 sites were used to describe the gap (< 0.1 ha) regime parameters, including gap fraction, gap size and change in disturbance severity through time. Three stand types were distinguished, based on a gradient of abundance of tree host species for the eastern spruce budworm. The impact of gaps was evaluated on the basis of changes in the number, the period of recruitment, and the composition of tree saplings present within gap areas. Changes were measured along the gap size gradient, and according to the pattern of recent budworm epidemics.Results: The gap fraction is highly variable (18%‐64%) and is on average relatively high (42%). Gap sizes have a positively skewed distribution. In most cases the growth rate among gap filling saplings increased sufficiently to date disturbance events. The composition and the structure of understory trees were affected by gap formation. The number of shade‐intolerant tree species did increase during or following periods of particularly severe canopy disturbances. However, the establishment or survival of shade intolerant species was not restricted to larger gaps or more intensely disturbed periods.Conclusions: In sub‐boreal forests of Eastern Canada, small scale disturbances in the tree canopy influence stand regeneration dynamics, but not to the extent that parameters such as sapling composition and recruitment patterns depend on gap regime characteristics.
Semi‐dry grasslands along a climatic gradient across Central Europe: Vegetation classification with validation
Authors: Illyés Eszter , Chytrý Milan , Botta‐Dukát Zoltán , Jandt Ute , Škodová Iveta , Janišová Monika , Willner Wolfgang , Hájek Ondřej 
Published: February 2009

AbstractQuestion: What is the variation in species composition of Central European semi‐dry grasslands? Can we apply a training‐and‐test validation approach for identifying phytosociological associations which are floristically well defined in a broad geographic comparison; can we separate them from earlier described associations with only a local validity?Location: A 1200 km long transect running along a gradient of increasing continentality from central Germany via Czech Republic, Slovakia, NE Austria, Hungary to NW Romania.Methods: Relevés with > 25% cover of Brachypodium pin‐natum and/or Bromus erectus were geographically selected from a larger database. They were randomly split into two data sets, TRAINING and TEST, each with 422 relevés. Cluster analysis was performed for each data set on scores from significant principal coordinates. Different partitions of the TRAINING data set were validated on the TEST data set, using a new method based on the comparison of % frequencies of species occurrence in clusters. Clusters were characterized by statistically defined groups of diagnostic species and values of climatic variables.Results: Species composition changed along the NW‐SE gradient and valid clusters were geographically well separated. Optimal partition level was at 11 clusters, six being valid: two clusters Germany and the Czech Republic corresponded to the Bromion erecti; two clusters from the Czech Republic and Hungary to the Cirsio‐Brachypodion, and two clusters were transitional between these two alliances.Conclusion: The training‐and‐test validation method used in this paper proved to be efficient for discriminating between robust clusters, which are appropriate candidates for inclusion in the national or regional syntaxonomic overviews, and weak clusters, which are specific to the particular classification of the given data set.
Plant dispersal strategies and the colonization of Araucaria forest patches in a grassland‐forest mosaic
Authors: Duarte Leandro da S. , Carlucci Marcos B. , Hartz Sandra M. , Pillar Valério D. 
Published: February 2009

AbstractQuestions: In a natural grassland‐forest mosaic: What is the influence of phylogeny and diaspore traits related to disperser attraction (DAT) on (1) seed size/number trade‐off (SSNT) in woody species colonizing forest patches; (2) on the frequency of the species? 3. What is the influence of forest patch area on mean seed size and number. 4. Do phylogeny and DAT expressed at the species level affect this relationship?Location: Campos grassland and Araucaria forest in São Francisco de Paula, RS, Brazil, at ca. 29°28’ S; 50° 13’ W.Methods: Forest patches of different sizes in a grassland site recovering for ten years since human disturbances were surveyed by the relative abundance of vertebrate‐dispersed woody saplings. We described colonizer species according to taxonomic phylogenetic relationships and diaspore type, size and color. We analyzed with a variation partitioning method their influence on SSNT and on species frequency in the patches. At the community level we regressed mean seed size and number on forest patch area and evaluated how these relationships were affected by phylogeny and DAT at the species level.Results: 1. Phylogeny and DAT mostly explained seed size and seed number per diaspore variation. 2. By controlling phylogeny and DAT influence the frequency of species in forest patches was positively associated with their seed number in the diaspores, and negatively associated with their seed size. 3. Mean seed size and seed number at the community level were positively associated with patch area. 4. When phylogeny and DAT influences on seed size were removed this relationship was stronger for seed size and weaker for seed number.Conclusions: 1. Energy allocation to dispersal in detriment of offspring survival increased the successful establishment of colonizer species in forest patches, despite phylogenetic relationships and DAT variation in their diaspores. 2. Although patch area exerted a selective pressure on seed size, habitat preferences of dispersers may also influence patch colonization.
Global Expression Profiling in Epileptogenesis: Does It Add to the Confusion?
Authors: Wang Yi Yuen , Smith Paul , Murphy Michael , Cook Mark 
Published: February 2009

AbstractSince the inception of global gene expression profiling platforms in the mid‐1990s, there has been a significant increase in publications of differentially expressed genes in the process of epileptogenesis. In particular for mesial temporal lobe epilepsy, the presence of a latency period between the first manifestation of seizures to chronic epilepsy provides the opportunity for therapeutic interventions at the molecular biology level. Using global expression profiling techniques, approximately 2000 genes have been published demonstrating differential expression in mesial temporal epilepsy. The majority of these changes, however, are specific to laboratory or experimental conditions with only 53 genes demonstrating changes in more than two publications. To this end, we review the current status of gene expression profiling in epileptogenesis and suggest standard guidelines to be followed for greater accuracy and reproducibility of results.
Performance evaluation of the PENTRA 60C+ automated hematology analyzer and comparison with the ADVIA 2120
Authors: GUERTI K. , VERTESSEN F. , DANIËLS L. , VAN DER PLANKEN M. 
Published: February 2009

SummaryThe PENTRA 60C+ hematology analyzer provides a complete blood cell (CBC) count, including a five‐part differential (5‐DIFF) count and two leukocyte subpopulations, i.e. large immature cells (LIC’s) and atypical lymphocytes (ALY’s). We evaluated its analytical performance and assessed agreement with the ADVIA 2120, in order to install the analyzer in a small satellite hematology laboratory. First we assessed repeatability, reproducibility and carry‐over to evaluate the analytical performance. Then we used Pearson correlation coefficients, Passing and Bablok regression analysis and a graphical approach (n = 209) to evaluate agreement with the ADVIA 2120. Repeatability and reproducibility were excellent for the majority of CBC and 5‐DIFF count parameters. Carry‐over was negligible. Our data showed very good correlation for most CBC count parameters. Lower correlation coefficients were observed for red cell distribution width, mean corpuscular volume and mean platelet volume. As compared to the ADVIA 2120, the 5‐DIFF count performed very well. Agreement was poorer for low‐level eosinophils and basophils. Furthermore, the PENTRA 60C+ was equally able to identify pathological blood samples through the determination of LIC’s and ALY’s. Therefore, the PENTRA 60C+ is an eligible blood cell counter to be operational in a satellite laboratory setting.
Quality assurance for point‐of‐care testing of oral anticoagulation: a large‐scale evaluation of the Hemochron Junior Signature Microcoagulation System
Authors: MADDOX J. M. , BOGO P. H. , McGREGOR E. , PIPPARD M. J. , KERR R. 
Published: February 2009

SummaryWe report the first large‐scale evaluation of the Hemochron Junior Signature (HJS) Microcoagulation System for community monitoring of oral anticoagulation and establishment of a programme of internal and external quality assurance. Over 1600 HJS results, with a simultaneous venous sample for central analysis, were obtained over a 19 month period. Monitoring of an initial period of HJS results (n = 135) revealed an International Normalized Ratio (INR) over estimation (mean +1.05), with only 27% of results within 0.5 of the central laboratory INR. A correction factor was introduced which reduced the INR bias to +0.07 and improved the percentage of results within 0.5 of the central laboratory INR to 76% (n = 353). A revised correction factor was later introduced to adjust for an under estimation at higher INR values. This changed the INR bias to –0.05, with 76% of results within 0.5 of the central laboratory INR (n = 1174). Local external quality assurance samples were distributed monthly with a total of 791 samples during the study period. 84% of test results were within 15% of the median value (range 73–97% per month). These results emphasize the value of a robust quality assurance programme when using point‐of‐care devices for community monitoring of oral anticoagulation.
Serum macrophage migration inhibitory factor (MIF) levels after allogeneic hematopoietic stem cell transplantation
Authors: TOUBAI T. , SHONO Y. , NISHIHIRA J. , IBATA M. , SUIGITA J. , KATO N. , OHKAWARA T. , TONE S. , LOWLER K. P. , OTA S. , TANAKA J. , ASAKA M. , REDDY P. , IMAMURA M. 
Published: February 2009

SummaryMacrophage migration inhibitory factor (MIF) may play an important role in the pathogenesis of acute graft‐versus‐host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo‐HSCT), as MIF plays an important role to regulate the production of tumor necrosis factor‐α (TNF‐α), one of the inflammatory cytokines which induces and exacerbates aGVHD. We examined the association between serum MIF levels and aGVHD vs. chronic GVHD (cGVHD) in allo‐SCT patients in this study. We found a significant increase in the peak serum MIF (14.46 ng ± 1.47 ng/ml) at onset in patients that developed aGVHD (n = 23, P = 0.009). We also found that mean serum MIF levels in patients who developed extensive type cGVHD within 6 months (12.58 ± 2.18 ng/ml, n = 13) were significantly higher than MIF levels before allo‐HSCT (7.86 ± 1.17 ng/ml, n = 19, P = 0.04). Therefore, we speculated that serum MIF levels increase during the active phase of both aGVHD and cGVHD.
Measurement of CD4+ T cells in point‐of‐care settings with the Sysmex pocH‐100i haematological analyser
Authors: BRIGGS C. , MACHIN S. , MÜLLER M. , HAASE W. , HOFMANN K. , FORSTREUTER F. , HINZMANN R. 
Published: February 2009

SummaryThe decision to provide antiretroviral therapy to HIV‐positive patients mainly depends on the CD4+ T‐cell count, with therapy indicated at a cut‐off value of <350–200 CD4+ T cells/μl blood. Monitoring patients is still a major problem in countries with limited resources where blood samples often have to be transported over long distances to regional referral centres in which the count can be performed on flow cytometers. We have evaluated a newly developed simple and inexpensive method for CD4+ T‐cell quantification. It is a variation of the Invitrogen T4 Quant kit, with manual isolation of nuclei from CD4+ T cells and subsequent counting on the small haematology analyser pocH‐100i, Sysmex. We have demonstrated that this new method is highly reproducible and gives stable and linear results over a wide range of CD4+ T‐cell concentrations. Method comparison to two different flow cytometers showed excellent correlation with concordances of about 93%. Overall, this method is rapid, easy to perform and offers a good reliable alternative to measurement by flow cytometry. The pocH‐100i has the additional benefit of providing a complete blood count with a three‐part white blood cell differential and software for patient data storage and handling.
Elevated expression of IL‐12 and IL‐23 in patients with aplastic anemia
Authors: GU Y. , ZHANG J. , PENG J. , HU X. , XU C. 
Published: February 2009

SummaryAplastic anemia (AA), which is characterized by hypocellular bone marrow (BM) and blood pancytopenia, was considered as a T‐helper1 (Th1) mediated disease. Interleukin (IL)‐12 and IL‐23 produced by antigen presenting cells are essential for inducing and sustaining Th1 effector cells via different pathways. However, less is known with regard to the levels of expression and synthesis of these two cytokines in patients with AA. This was determined in the current study in 26 patients with AA as well as in 20 healthy controls. Our results showed that IL‐12 p40, IL‐12 p35 and IL‐23 p19 gene expression can be detected in all samples both from the patients and the controls, using real‐time reverse transcription polymerase chain reaction. Furthermore, an increased expression of IL‐12 p40, IL‐12 p35 and IL‐23 p19 mRNA was observed in bone marrow mononuclear cells and peripheral blood mononuclear cells of patients with AA compared with the corresponding one in normal controls. Higher levels of IL‐12 and IL‐23 were also found in BM plasma and PB plasma in patients with AA than in normal controls. Therefore, the augmented expression of IL‐12 and IL‐23 in patients with AA may play an important role in the pathogenesis of this disease.