bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative histopathological analysis between tenosynovitis and joint synovitis in rheumatoid arthritis
Authors: Kaibara N , Yamada H , Shuto T , Nakashima Y , Okazaki K , Miyahara H , Esaki Y , Hirata G , Iwamoto Y 
Published: May 2008

Aims:  To clarify the histological and biological features of tenosynovitis accompanying rheumatoid arthritis (RA).Methods and results:  Synovial tissue was obtained from the wrist joint and extensor tendon of the digits of six RA patients and the sections were examined by haematoxylin and eosin staining and immunohistochemical analysis. RA tenosynovitis exhibited the typical histological features of RA joint synovitis, including hyperplasia of the synovial lining and infiltration of leucocytes, largely CD4+ T cells and CD68+ macrophages. Notably, there was a significant correlation in the number of CD4+ T cells and CD68+ macrophages between the tenosynovium and joint synovium in each individual. Real‐time reverse transcriptase‐polymerase chain reaction analysis revealed similar mRNA expression patterns of various inflammatory mediators in tenosynovitis and joint synovitis. It was also observed that synovial fibroblasts isolated from the tenosynovium behaved in a manner similar to those isolated from the joint synovium with regard to proliferation and the production of inflammatory mediators.Conclusions:  The histopathological features of RA tenosynovitis were indistinguishable from those of joint synovitis. Therefore, it is suggested that the ongoing inflammation is driven by similar mechanisms in the tenosynovium and joint synovium and that RA is probably a tissue‐specific disease which targets systemic synovial tissues.
Detection of spirochaetal microorganisms by focus floating microscopy in necrobiosis lipoidica in patients from central Europe
Authors: Eisendle K , Baltaci M , Kutzner H , Zelger B 
Published: May 2008

Aims:  Necrobiosis lipoidica (NL) is a chronic inflammatory skin disease with unknown aetiology. The aim was to determine the presence of spirochaetal microorganisms in NL.Methods and results:  Focus‐floating microscopy (FFM) is a modified immunohistochemical technique that was developed to detect borrelial spirochaetes within tissue sections. It has proven to be more sensitive for the detection of spirochaetes than polymerase chain reaction (PCR). Fifty‐six cases of NL as well as 44 negative and 33 positive controls were investigated for the presence of Borrelia within tissue specimens. Using FFM, Borrelia could be detected in 42 cases (75.0%) and were seen significantly more often in histologically active inflammatory‐rich (38/41, 92.7%) than in inflammatory‐poor (4/15, 26.7%) cases of NL (P < 0.001). Seven cases investigated with a Borrelia‐specific PCR (23s‐RNA) remained negative. In contrast, FFM was positive in 30 of 33 (90.9%) positive controls of acrodermatitis chronica atrophicans and 15 of the positive controls (45.5%) were also positive with PCR, whereas no negative controls revealed any microorganisms.Conclusions:  Detection of spirochaetes in NL points to a specific involvement of B. burgdorferi or other similar strains in the development of or trigger for this disease.
Altered editing in cyclic nucleotide phosphodiesterase 8A1 gene transcripts of systemic lupus erythematosus T lymphocytes
Authors: Orlowski Robert J. , O’Rourke Kenneth S. , Olorenshaw Irene , Hawkins Gregory A. , Maas Stefan , Laxminarayana Dama 
Published: May 2008

SummaryThe aetiopathogenesis of the abnormal immune response in systemic lupus erythematosus (SLE) remains incompletely understood. We and other investigators demonstrated altered expression of adenosine deaminase that act on RNA (ADAR) genes in SLE patients. Based on this information, we hypothesize that the altered expression and function of ADAR enzymes is a mechanism for the immunopathogenesis of SLE. ADARs edit gene transcripts through site‐specific conversion of adenosine to inosine by hydrolytic deamination at C6 of the adenosine. Thirteen SLE subjects and eight healthy controls were studied. We assessed the role of ADAR enzymes in editing of PDE8A1 gene transcripts of normal and SLE T cells. These studies demonstrated the occurrence of ADAR‐catalysed altered and site‐selective editing profile of specific sites in the PDE8A1 gene transcripts of normal and SLE T cells. Two hot spots for A to I editing were observed in the PDE8A1 transcripts of normal and SLE T cells. A fundamental finding of this study is A to I hypo‐editing followed by up‐regulation of PDE8A1 transcripts in SLE T cells. These results are confirmed by analysing PDE8A1 transcripts of normal T cells activated with type I interferon‐α. It is proposed that, the altered expression of ADAR enzymes tilt the balance of editing machinery and alter editing in SLE transcriptome. Such altered editing may contribute to the modulation of gene regulation and ultimately, immune functions in SLE and play an important role in the initiation and propagation of SLE pathogenesis.
ORIGINAL ARTICLE: Human impact on an island ecosystem: pollen data from Sandoy, Faroe Islands
Authors: Lawson Ian T. , Edwards Kevin J. , Church Mike J. , Newton Anthony J. , Cook Gordon T. , Gathorne‐Hardy Freddy J. , Dugmore Andrew J. 
Published: May 2008

AbstractAim To investigate the form and dynamics of ecosystems on an isolated island in the North Atlantic before human settlement in the first millenniumad, and the effects of human activities thereafter.Location The island of Sandoy, Faroes (61°50′ N, 6°45′ W).Methods Two sequences of lake sediments and one of peat were studied using pollen analysis and sedimentological techniques. Age models were constructed on the basis of radiocarbon dating and, in one case, tephrochronology. The data were analysed statistically and compared with existing data from the region.Results The pollen data indicate that early Holocene vegetation consisted of fell‐field communities probably growing on raw, skeletal soils. These communities gave way to grass‐ and sedge‐dominated communities, which in turn were largely replaced by dwarf shrub‐dominated blanket mire communities well before the first arrival of humans. There is evidence for episodic soil erosion, particularly in the uplands. Changes in the records attributable to human impact are minor in comparison with many other situations in the North Atlantic margins, and with certain published sequences from elsewhere in the Faroes. They include: (1) the appearance of cereal pollen and charcoal, (2) an expansion of ruderal taxa, (3) a decline in certain taxa, notablyJuniperus communisandFilipendula ulmaria, and (4) a renewed increase in rates of upland soil erosion. The reliability of palaeoecological inferences drawn from these sites, and more generally from sites in similar unforested situations, is discussed.Main conclusions The subdued amplitude of palynological and sedimentological responses to settlement at these sites can be explained partly in terms of their location and partly in terms of the sensitivity of different parts of the ecosystem to human activities. This study is important in establishing that the imposition of people on the pristine environment of Sandoy, while far from negligible, especially in the immediate vicinity of early farms and at high altitudes, had relatively little ecological impact in many parts of the landscape.
ORIGINAL ARTICLE: Extinction of the autochthonous small mammals of Mallorca (Gymnesic Islands, Western Mediterranean) and its ecological consequences
Authors: Bover Pere , Alcover Josep Antoni 
Published: May 2008

AbstractAim  To investigate the chronology, causes and consequences of the extinction of the autochthonous Pleistocene small mammals of Mallorca.Location  Mallorca (Gymnesic Islands, Balearics, Western Mediterranean).Methods  We have obtained the first direct 14C ages from the bone collagen of selected samples of two extinct endemic small mammals from Mallorca: the Balearic dormouse, Eliomys morpheus (Rodentia: Myoxidae) and the Balearic shrew, Asoriculus hidalgoi (Soricomorpha: Soricidae). We also present evidence for the absence of both endemics from the earliest Mallorcan archaeological sites and for the introduction of the garden dormouse, Eliomys quercinus, and the wood mouse, Apodemus sylvaticus. Combined information from direct dating of bone collagen of E. quercinus and A. sylvaticus and from cultural associations provides an adequate framework to establish the chronology of the faunal change and to compare it with the chronological information available on climatic change and the first arrival of humans on the islands.Results  The chronological record includes the latest evidence available for the survival of endemic species and the earliest introduction of small mammals into Mallorca. We present ‘uncertainty periods for extinction’ (UPEs) of both endemic mammals based on the chronology of their last occurrence and on the inferred timing of their extinction (restricted UPEs).Main conclusions  Possible causes for the extinction of autochthonous small mammals on Mallorca are discussed. Once we have discarded climatic causes, predation by invasive species, competition with newcomers and habitat deterioration, the introduction of diseases emerges as the most reasonable explanation for these extinctions. Based on the identification of changes in keystone species in Mallorcan ecosystems, we propose a tentative schedule of key ecological changes that have taken place over the past 5 millennia.
ORIGINAL ARTICLE: Turnover of plants on small islets of the eastern Aegean Sea within two decades
Authors: Panitsa Maria , Tzanoudakis Dimitrios , Sfenthourakis Spyros 
Published: May 2008

AbstractAim  To estimate species turnover of plants on 32 small islands within a 20‐year period and to assess possible changes in community composition and properties, such as species richness and factors affecting it, nestedness, species co‐occurrence and overall community similarity. Additionally, to assess the possible effects of grazing, gull colonies and fire on turnover values.Location  Thirty‐two islets in the eastern Aegean Sea (Greece).Methods  Complete sampling of plants was performed in 1974 and in 1990–94 (mostly in 1994, which was used as the reference year). Species turnover rates were estimated using both per island and per species approaches. Multiple regression was used to evaluate factors affecting species richness. Chi‐square tests were applied to compare community composition among sampling periods. The effects of various factors on turnover rates and species richness were examined using one‐way anova and ancova. Mann–Whitney tests were applied in order to check for differences between frequencies of occurrence of extinct, immigrant and persisting species. Community nestedness was calculated using bitmatnest and the C‐score index for co‐occurrence was estimated using EcoSim7. Species similarities among islands in each of the 1974 and 1994 data sets were assessed using Jaccard’s index and the two similarity matrices were compared using a Mantel test.Results  Of 391 species recorded on the islets, 334 were present in 1974, 301 in 1994 and 244 were common to both these periods. Species richness in the 1974 and 1994 data sets was significantly correlated with elevation and area, but not with distance from the nearest large island. Richness was positively affected by grazing, but not by fire or gull colonies. The slopes of species–area and species–elevation regressions were almost identical in 1974 and 1994. Mean relative turnover was 2.06 (species per islet) and 3.26 (islets per species). Turnover was not correlated with area, elevation or distance from the nearest large island. Nestedness and co‐occurrence levels were very similar. Tables of islet by islet floral similarity (Jaccard’s index) did not differ between the 1974 and 1994 data sets.Main conclusions  The turnover rates found are among the highest recorded for plants; at the same time the islet communities exhibit notable stability in overall properties. Our results provide evidence for rapid shifts in species number that may nonetheless be considered as equilibrial dynamics, as these islets are able to respond rapidly to environmental change and disturbance. Human activities, notably the application of grazing, have a significant complicating effect on community dynamics, enhancing observed turnover rates.
ORIGINAL ARTICLE: Mass extinctions in the Azores during the last glaciation: fact or myth?
Authors: Ávila Sérgio P. , Madeira Patrícia , Mendes Nuno , Rebelo Ana , Medeiros André , Gomes Cidalina , García‐Talavera Francisco , Da Silva Carlos Marques , Cachão Mário , Hillaire‐Marcel Claude , De Frias Martins António M. 
Published: May 2008

AbstractAim  The influence of the last glaciation on the shallow‐water marine malacofauna of the Azores Islands is reviewed. We test, for this fauna, the ‘Pleistocene temperature theory’ of J.C. Briggs, which hypothesizes that a (supposed) lack of endemics in the older (Azorean endemic) fauna resulted from extinctions caused by a severe drop in sea surface temperatures during the Pleistocene.Location  Santa Maria Island, Azores, Portugal.Methods  We compare the fossil mollusc fauna of Prainha, Praia do Calhau and Lagoinhas Pleistocene outcrops with the recent mollusc fauna of the Azores Islands. We dated the fossil fauna, using shells of Patella aspera Röding, 1798, by standard U/Th methodology at the GEOTOP laboratory (Université du Québec à Montreal, Canada).Results  Dating of the shells of P. aspera indicates that the deposition of the lower unit of the Prainha outcrop corresponded to Marine Oxygen Isotope Substage 5e (MISS 5e). Not a single endemic Azorean species of mollusc that is present in the Pleistocene fossil record has since become extinct, and we found no signs of ‘mass extinctions’ in the littoral marine molluscs of the Azores. The only species that were extirpated from these islands were thermophilic molluscs and littoral bivalves living in fine sand.Main conclusions  Our results do not support Briggs’‘Pleistocene temperature theory’. Nor did we find evidence supporting the hypothesis that most of the marine organisms now present in the Azores recolonized the islands after the last glacial maximum.
Translocation of nitrogen and carbon integrates biotic crust and grass production in desert grassland
Authors: Green Laura E. , Porras‐Alfaro Andrea , Sinsabaugh Robert L. 
Published: May 2008

Summary

Arid ecosystems are a patch mosaic of plants and biological soil crusts that have been described as islands and mantles of fertility, respectively. To determine whether these patches are metabolically linked by a fungal network of dark septate and arbuscular mycorrhizal fungi (AMF), we measured translocation of nitrogen (N) and carbon (C) in a desert grassland using 15N‐NO3 and 13C5, 15N‐glutamic acid as substrates.
Substrates were applied as point sources to either small patches of biotic crust or to a subset of leaves within a bunch grass tussock.
Both substrates were translocated over approximately 1 m2 areas (approximately 20 patches) at rates up to 100 cm day−1 during a 4‐day period following a natural rainfall event. Foliar uptake of 15N from glutamate was initially more rapid than 15N uptake from nitrate, and translocation from foliage was initially more rapid than translocation from soil crust. Rates of 15N translocation between patches were similar to rates of atmospheric N deposition and denitrification.
13C from 13C5, 15N‐glutamic acid applied to leaves was translocated to crust suggesting that plant C may provide metabolic support to biological soil crusts during periods of active growth. 13C from 13C5, 15N‐glutamic acid applied to soil crusts did not enter plants, in contrast to the 15N from this substrate, indicating that glutamate was not translocated intact.
The dominant fungi of roots, rhizosphere soil and biological soil crusts are dark septate ascomycetes, most classified as Pleosporales, and AMF are rare. Phylogenetic analyses indicate substantial overlap in fungal community composition between roots and crusts, which may facilitate nutrient transfers.
Synthesis. This study supports the hypothesis that the spatial structure of semi‐arid ecosystems, a patch mosaic of grasses and biological soil crust described, respectively, by the island of fertility and mantle of fertility paradigms, is functionally integrated by exchanges of C and N through a symbiotic fungal network dominated by dark‐septate fungi.
Tree species identity alters forest litter decomposition through long‐term plant and soil interactions in Patagonia, Argentina
Authors: Vivanco Lucía , Austin Amy T. 
Published: May 2008

SummaryA major challenge in predicting biodiversity effects on ecosystem functioning is to understand the linkages between above‐ground and below‐ground components in natural communities. However, incongruities in spatial and temporal scale between plant and soil processes, and confounding ecological factors, have impeded our understanding of biodiversity effects on below‐ground processes, particularly in natural ecosystems with long‐lived species such as forests.We designed an approach to isolate plant species composition effects from other ecosystem factors, in order to evaluate the effects of individual tree species and tree species mixtures on litter decomposition in a mixed old‐growth forest in temperate South America. We identified ‘tree triangles’ where the intersection of plant canopies directly controlled micro‐environmental and biogeochemical conditions on the forest floor. The monospecific treatment included triangles composed of three trees of a single species ofNothofagus dombeyi,N. obliqua or N. nervosa, while the mixed‐species triangles consisted in the intersections of the three differentNothofagusspecies.We placed litterbags withN. dombeyi,N. obliqua or N. nervosalitter and mixed litter of the three species within all these triangles and estimated the decomposition constant (k) after 1 year of incubation. We also used a standard litter type in all triangles to independently evaluate the tree triangle effects on decomposition.We found that plant species affected decomposition through both direct and indirect effects. Direct effects were mediated through leaf litter quality, while indirect effects were related to unique conditions that the plant species created in the surrounding environment. Despite litter decomposition variation among triangles, standard soil biogeochemical conditions such as soil C : N ratios, microbial biomass and pH were similar among microsites.Most interestingly, we explicitly demonstrated that long‐term effects of plant species created specific conditions that enhanced decomposition of their own litter, establishing affinity effects between single‐species litter and their own microenvironment.Synthesis.Our results highlight that plant species identity and long‐term plant–soil feedbacks are important in affecting litter decomposition in this temperate Patagonian forest. Thus, changes or losses in temperate forest above‐ground biodiversity can directly impact litter decomposition both through changes in litter quality inputs and, additionally, through the loss of specific plant–soil interactions that affect below‐ground processes.
Functional identity is more important than diversity in influencing ecosystem processes in a temperate native grassland
Authors: Mokany Karel , Ash Julian , Roxburgh Stephen 
Published: May 2008

Summary

Experimental studies have provided significant knowledge of how biodiversity can influence ecosystem processes. However, there is a growing need to relate these findings to natural communities.
Here we identify two major hypotheses for how communities may influence ecosystem processes: the ‘diversity hypothesis’ (the diversity of organisms in a community influences ecosystem processes through mechanisms such as complementary resource use), and the ‘mass ratio hypothesis’ (ecosystem processes are determined overwhelmingly by the functional traits of the dominant species). We then test which of these two hypotheses best explain variation in ecosystem properties and processes (biomass pools and fluxes, water use, light interception) in a temperate native grassland. We do this by applying various measures of diversity, functional diversity, and functional identity, whose significant relations with ecosystem processes would support either of the competing hypotheses.
Mean trait values best explained variation in five of the eight ecosystem processes examined, supporting Grime's mass ratio hypothesis, which proposes that the functional identities of the dominant species largely determine ecosystem processes.
Multi‐trait functional diversity indices also explained large amounts of variation in ecosystem processes, while only weak relationships were observed between species richness and ecosystem processes.
To explore the mechanistic interactions between variables, we developed structural equation models (SEMs), which indicated that many of the community diversity and trait properties significantly influenced ecosystem processes, even after accounting for co‐varying biotic/abiotic factors.
Synthesis. Our study is one of the first explicit comparisons of the ‘diversity’ and ‘mass ratio’ hypotheses, and our results most strongly support the mass ratio hypothesis, that is, the traits of the dominant species most influenced the ecosystem properties and processes examined. Our results suggest that the management of communities for the maintenance of ecosystem processes should focus on species dominance hierarchies.
Coevolutionary relationship between helminth diversity and MHC class II polymorphism in rodents
Authors: GOÜY DE BELLOCQ J. , CHARBONNEL N. , MORAND S. 
Published: May 2008

AbstractParasite‐mediated selection on major histocompatibility complex (MHC) genes has mainly been explored at the intraspecific level, although many molecular studies have revealed trans‐species polymorphism. Interspecific patterns of MHC diversity might reveal factors responsible for the long‐term evolution of MHC polymorphism. We hypothesize that host taxa harbouring high parasite diversity should exhibit high levels of MHC genetic diversity. We test this assumption using data on rodent species and their helminth parasites compiled from the literature. Controlling for similarity due to common descent, we present evidence indicating that high helminth species richness in rodent species is associated with increased MHC class II polymorphism. Our results are consistent with the idea that parasites sharing a long‐term coevolutionary history with their hosts are the agents of selection explaining MHC polymorphism.
Experimental evolution of field populations of Daphnia magna in response to parasite treatment
Authors: ZBINDEN M. , HAAG C. R. , EBERT D. 
Published: May 2008

AbstractAlthough there is little doubt that hosts evolve to reduce parasite damage, little is known about the evolutionary time scale on which host populations may adapt under natural conditions. Here we study the effects of selection by the microsporidian parasite Octosporea bayeri on populations of Daphnia magna. In a field study, we infected replicated populations of D. magna with the parasite, leaving control populations uninfected. After two summer seasons of experimental evolution (about 15 generations), the genetic composition of infected host populations differed significantly from the control populations. Experiments revealed that hosts from the populations that had evolved with the parasite had lower mortality on exposure to parasite spores and a higher competitive ability than hosts that had evolved without the parasite. In contrast, the susceptibility of the two treatment groups to another parasite, the bacterium Pasteuria ramosa, which was not present during experimental evolution of the populations, did not differ. Fitness assays in the absence of parasites revealed a higher fitness for the control populations, but only under low population density with high resource availability. Overall, our results show that, under natural conditions, Daphnia populations are able to adapt rapidly to the prevailing conditions and that this evolutionary change is specific to the environment.