bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multi‐scale analysis of responses of stream macrobenthos to forestry activities and environmental context
Authors: MARTEL NICOLAS , RODRÍGUEZ MARCO A. , BÉRUBÉ PIERRE 
Published: November 2006

Summary1. Forestry activities can greatly modify the structure and function of invertebrate communities in streams, but the ability to detect effects of forestry may depend on the spatial scale considered, the choice of response metric and the environmental context. In this study, a multi‐scale, multi‐metric approach was used to compare the usefulness of proximate and larger‐scale measurements of forestry activity for understanding the impacts of forestry on stream macrobenthos.2. Site‐specific responses of macrobenthic communities to forestry activities measured at four spatial scales (sub‐basin and 8‐, 2‐ and 0.5‐km radii upstream of study sites) were examined for 90 riffle sites distributed among 22 tributary streams (Strahler order 1–5) of the Cascapedia River basin, Quebec, Canada.3. Multiple regression models and canonical correspondence analysis were used to relate six biological metrics (taxonomic richness, numerical density, biomass density, normalised biomass spectrum, individual body mass and community structure) to variables quantifying logging 1–19 years prior to the study and road density. Environmental predictors (variables quantifying local habitat or landscape features) were included in all analyses to statistically account for environmental context and increase the likelihood of detecting potentially subtle forestry impacts.4. Forestry activities measured at the larger (sub‐basin and 8 km) scales were linked to decline in taxonomic richness, increase in numerical and biomass densities and shift in size structure of benthic macroinvertebrates, indicating that analyses encompassing larger areas, up to the full basin, may allow for more sensitive detection of effects than those of more limited span.5. These responses primarily reflected marked increases in the abundance of chironomids and decline in the number of trichopteran taxa with increasing areal coverage of recent (≤2–4 years) cuts, suggesting that larger, longer‐lived and possibly more specialised taxa were more vulnerable to forestry impacts than smaller, multivoltine, generalist invertebrates. After partialling out the influence of other variables, rapid decline in richness occurred even when <1% of the basin had been clear cut in the year prior to the study.6. Effects of forestry were detected after statistically accounting for natural environmental variability, which may have otherwise concealed those effects. The combined use of multiple biological metrics, partialling out of environmental effects and measurement of impacts at multiple spatial scales may be a broadly applicable approach for enhancing sensitivity and facilitating interpretation in studies of anthropogenic effects on macroinvertebrate communities.
The response of macroinvertebrate production to a pollution gradient in a headwater stream
Authors: WOODCOCK THOMAS S. , HURYN ALEXANDER D. 
Published: November 2006

Summary1. This study quantified patterns of macroinvertebrate secondary production and stored benthic organic matter along a gradient of pollution and habitat channelisation over a 3‐km reach of Goosefare Brook, a first‐order stream in southern Maine (U.S.A.).2. Whole‐community invertebrate production decreased from 26.4 g ash‐free dry mass (AFDM) m−2 year−1 at the reference station to 1.1 g AFDM m−2 year−1 at stations with the greatest levels of pollution. Production decreased along the pollution gradient for most taxa, although decreases were partly offset by production increases in tolerant taxa. Biomass turnover rates (P/B) were less affected by the stresses than was production.3. Differences in functional characteristics of the community were evident at stations with channelised habitat, but overall production declined in a linear pattern that mirrored the pollution gradient. Stored organic matter showed a decline along the gradient, but was also lower at channelised stations. Populations of taxa with documented pollution tolerance were more likely to maintain or increase production and P/B.4. Decreasing biomass because of decreasing stored organic matter and lethal effects of pollutants resulted in shifts in the pathways of energy flow observed at stations exposed to moderate physical or chemical stress, to the loss of most taxa and an extreme (96%) decrease in production at the stations receiving the highest levels of metal pollution.5. The shifting prominence of different taxa along a continuum of stress in Goosefare Brook shows that describing the nature of an impairment in a functional context requires consideration of chemical stressors, habitat alterations and food resources.
The effect of host Chlorella NC64A carbon : phosphorus ratio on the production of Paramecium bursaria Chlorella Virus‐1
Authors: CLASEN JESSICA L. , ELSER JAMES J. 
Published: November 2006

Summary1. We used the freshwater alga Chlorella NC64A (Division Chlorophyta) and its virus Paramecium bursaria Chlorella virus‐1 (PBCV‐1) as a model system to test for potential stoichiometric constraints on a virus–host interaction.2. Media phosphorus concentrations were manipulated to create Chlorella NC64A host cells with low (91 ± 23) or high (453 ± 246) C : P ratio. In contrast, the C : P ratio of PBCV‐1, calculated from its biochemical composition, was 17 : 1.3. Stoichiometric theory predicts that infection success and postinfection viral production should be depressed in high C : P cultures due to insufficient intracellular P for production of P‐rich viral particles.4. Consistent with this hypothesis, viral production was strongly affected by host C : P ratio. While host C : P ratio did not affect viral attachment or the percentage of new viral particles that were infectious, in the low C : P Chlorella NC64A treatment, nine times more viruses were produced per infected cell than in the high C : P treatment (158 ± 138 versus 18 ± 18), indicating that the low C : P cells were higher quality for PBCV‐1 proliferation.5. This result implies that the stoichiometric quality of algal cells can have a major effect on host–virus population dynamics.
Brown trout and food web interactions in a Minnesota stream
Authors: ZIMMERMAN JULIE K. H. , VONDRACEK BRUCE 
Published: November 2006

Summary1. We examined indirect, community‐level interactions in a stream that contained non‐native brown trout (Salmo trutta Linnaeus), native brook trout (Salvelinus fontinalis Mitchill) and native slimy sculpin (Cottus cognatus Richardson). Our objectives were to examine benthic invertebrate composition and prey selection of fishes (measured by total invertebrate dry mass, dry mass of individual invertebrate taxa and relative proportion of invertebrate taxa in the benthos and diet) among treatments (no fish, juvenile brook trout alone, juvenile brown trout alone, sculpin with brook trout and sculpin with brown trout).2. We assigned treatments to 1 m2 enclosures/exclosures placed in riffles in Valley Creek, Minnesota, and conducted six experimental trials. We used three designs of fish densities (addition of trout to a constant number of sculpin with unequal numbers of trout and sculpin; addition of trout to a constant number of sculpin with equal numbers of trout and sculpin; and replacement of half the sculpin with an equal number of trout) to investigate the relative strength of interspecific versus intraspecific interactions.3. Presence of fish (all three species, alone or in combined‐species treatments) was not associated with changes in total dry mass of benthic invertebrates or shifts in relative abundance of benthic invertebrate taxa, regardless of fish density design.4. Brook trout and sculpin diets did not change when each species was alone compared with treatments of both species together. Likewise, we did not find evidence for shifts in brown trout or sculpin diets when each species was alone or together.5. We suggest that native brook trout and non‐native brown trout fill similar niches in Valley Creek. We did not find evidence that either species had an effect on stream communities, potentially due to high invertebrate productivity in Valley Creek.
The influence of biotope availability on macroinvertebrate assemblages in South African rivers: implications for aquatic bioassessment
Authors: DALLAS HELEN F. 
Published: November 2006

Summary1. Macroinvertebrate biotope preferences and the influence of differences in the availability of biotopes on individual taxa, macroinvertebrate assemblages and a biotic index, the South African Scoring System (SASS), were investigated in two regions of South Africa.2. Among biotope differences in individual taxa and macroinvertebrate assemblages resulted in differences in SASS scores, with differences in assemblages being greater among biotopes than between sites.3. All three metrics studied (SASS score, number of taxa and average score per taxon, ASPT), differed significantly among biotopes, with highest scores consistently recorded in the stones biotope, while lowest SASS scores and fewest taxa were recorded in the sand biotope.4. SASS score and number of taxa were positively, while ASPT was negatively correlated with number of biotopes sampled.5. The observed biotope differences highlight the importance of sampling and comparing data from sites separately for each biotope.
Challenges to estimating carbon emissions from tropical deforestation
Authors: RAMANKUTTY NAVIN , GIBBS HOLLY K. , ACHARD FRÉDÉRIC , DEFRIES RUTH , FOLEY JONATHAN A. , HOUGHTON R. A. 
Published: November 2006

AbstractAn accurate estimate of carbon fluxes associated with tropical deforestation from the last two decades is needed to balance the global carbon budget. Several studies have already estimated carbon emissions from tropical deforestation, but the estimates vary greatly and are difficult to compare due to differences in data sources, assumptions, and methodologies. In this paper, we review the different estimates and datasets, and the various challenges associated with comparing them and with accurately estimating carbon emissions from deforestation. We performed a simulation study over legal Amazonia to illustrate some of these major issues. Our analysis demonstrates the importance of considering land‐cover dynamics following deforestation, including the fluxes from reclearing of secondary vegetation, the decay of product and slash pools, and the fluxes from regrowing forest. It also suggests that accurate carbon‐flux estimates will need to consider historical land‐cover changes for at least the previous 20 years. However, this result is highly sensitive to estimates of the partitioning of cleared carbon into instantaneous burning vs. long‐timescale slash pools. We also show that carbon flux estimates based on ‘committed flux’ calculations, as used by a few studies, are not comparable with the ‘annual balance’ calculation method used by other studies.
Functional characterization of a T‐cell receptor BV6+ T‐cell clone derived from a leprosy lesion
Authors: Sabet Shereen , Ochoa Maria‐Teresa , Sieling Peter A. , Rea Thomas H. , Modlin Robert L. 
Published: November 2006

SummaryHuman infection with Mycobacterium leprae, an intracellular bacterium, presents as a clinical and immunological spectrum; thus leprosy provides an opportunity to investigate mechanisms of T‐cell responsiveness to a microbial pathogen. Analysis of the T‐cell receptor (TCR) repertoire in leprosy lesions revealed that TCR BV6+ T cells containing a conserved CDR3 motif are over‐represented in lesions from patients with the localized form of the disease. Here, we derived a T‐cell clone from a leprosy lesion that expressed TCR BV6 and the conserved CDR3 sequence L‐S‐G. This T‐cell clone produced a T helper type 1 cytokine pattern, directly lysed M. leprae‐pulsed antigen‐presenting cells by the granule exocytosis pathway, and expressed the antimicrobial protein granulysin. BV6+ T cells may therefore functionally contribute to the cell‐mediated immune response against M. leprae.
Degradation of trans‐polyisoprene over time following the analysis of root fillings removed during conventional retreatment
Authors: Maniglia‐Ferreira C. , Silva J. B. A. , De Paula R. C. M. , Feitosa J. P. A. , Zaia A. A. , Ferraz C. C. R. , Gomes B. P. F. A. , Souza‐Filho F. J. 
Published: November 2006

AbstractAim  To evaluate in vivo degradation of root filling materials over time.Methodology  Thirty‐six root filled teeth with or without periapical lesions were selected. Teeth with poor coronal restoration were not included. The teeth had been root filled 3–30 years previous and were scheduled for conventional retreatment. The association of root canal treatment, age, periapical lesion and root filling degradation was investigated. The filling material was removed from the root canal using files and no solvent. Trans‐1,4‐polyisoprene was isolated through solubilization of root filling remnants in chloroform followed by filtration and centrifugation. Gel permeation chromatography (GPC) and infrared spectroscopy (FT‐IR) were utilized to study the occurrence and degree of degradation. The GPC and FT‐IR data were collected for each sample and analysed statistically using the Kruskal–Wallis test.Results  Degradation of trans‐1,4‐polyisoprene was a slow process. The process was identified as an oxidation reaction through the production of carboxyl and hydroxyl groups. Compared with the control group, significant molar mass decrease was noted after 15 years (P = 0.0146) in teeth with no periapical lesions. However, in teeth associated with periapical lesions the number of years for significant degradation was reduced to 5 (P = 0.0009).Conclusion  Polyisoprene degrades inside root canals as an oxidative process. The presence of periapical lesions was associated with a more rapid onset of degradation.
Antibacterial efficacy of calcium hydroxide intracanal dressing: a systematic review and meta‐analysis
Authors: Sathorn C. , Parashos P. , Messer H. 
Published: November 2006

AbstractAim  To determine to what extent does calcium hydroxide intracanal medication eliminate bacteria from human root canals, compared with the same canals before medication, as measured by the number of positive cultures, in patients undergoing root canal treatment for apical periodontitis (teeth with an infected root canal system).Methodology  CENTRAL, MEDLINE and EMBASE databases were searched. Reference lists from identified articles were scanned. A forward search was undertaken on the authors of the identified articles. Papers that had cited these articles were also identified through the Science Citation Index to identify potentially relevant subsequent primary research.Review methods  The included studies were pre‐/post‐test clinical trials comparing the number of positive bacterial cultures from treated canals. Data in those studies were independently extracted. Risk differences of included studies were combined using the generic inverse variance and random effect method.Results  Eight studies were identified and included in the review, covering 257 cases. Sample size varied from 18 to 60 cases; six studies demonstrated a statistically significant difference between pre‐ and post‐medicated canals, whilst two did not. There was considerable heterogeneity among studies. Pooled risk difference was −21%; 95% CI: −47% to 6%. The difference between pre‐ and post‐medication was not statistically significant (P = 0.12).Conclusions  Calcium hydroxide has limited effectiveness in eliminating bacteria from human root canal when assessed by culture techniques.
Evaluation of immunological parameters in farmed gilthead sea bream, Sparus aurata L., before and during outbreaks of ‘winter syndrome’
Authors: Contessi B , Volpatti D , Gusmani L , Galeotti M 
Published: November 2006

AbstractIn recent years, ‘winter syndrome’ has caused severe economic losses in many marine farms in southern Europe. This study compared the activity of the immune system in healthy, asymptomatic and diseased gilthead sea bream. Serum protein and immunoglobulin content were evaluated as well as serum complement activity from these groups of fish. Differential leucocyte counts were also determined. Immunological assays were performed to determine intra‐ and extracellular ‘respiratory burst’ activity as non‐specific immune response parameters. Diseased fish showed a significant reduction in haemolytic activity (90%), and in serum proteins and immunoglobulins in comparison with the other groups. A significant increase in the lymphocyte percentage (50%) and a decrease in the granulocyte percentage (over 70%) was found in asymptomatic fish. Respiratory burst activity was reduced in both the clinical and preclinical stages of the disease, compared with the controls. These observations confirm a severe immunodeficiency in diseased fish but also the presence of a cellular immune dysfunction in fish without clinical signs, before the onset of the disease.
Priming by airborne signals boosts direct and indirect resistance in maize
Authors: Ton Jurriaan , D'Alessandro Marco , Jourdie Violaine , Jakab Gabor , Karlen Danielle , Held Matthias , Mauch‐Mani Brigitte , Turlings Ted C.J. 
Published: November 2006

SummaryPlants counteract attack by herbivorous insects using a variety of inducible defence mechanisms. The production of toxic proteins and metabolites that instantly affect the herbivore's development are examples of direct induced defence. In addition, plants may release mixtures of volatile organic compounds (VOCs) that indirectly protect the plant by attracting natural enemies of the herbivore. Recent studies suggest that these VOCs can also prime nearby plants for enhanced induction of defence upon future insect attack. However, evidence that this defence priming causes reduced vulnerability to insects is sparse. Here we present molecular, chemical and behavioural evidence that VOC‐induced priming leads to improved direct and indirect resistance in maize. A differential hybridization screen for inducible genes upon attack by Spodoptera littoralis caterpillars identified 10 defence‐related genes that are responsive to wounding, jasmonic acid (JA), or caterpillar regurgitant. Exposure to VOCs from caterpillar‐infested plants did not activate these genes directly, but primed a subset of them for earlier and/or stronger induction upon subsequent defence elicitation. This priming for defence‐related gene expression correlated with reduced caterpillar feeding and development. Furthermore, exposure to caterpillar‐induced VOCs primed for enhanced emissions of aromatic and terpenoid compounds. At the peak of this VOC emission, primed plants were significantly more attractive to parasitic Cotesia marginiventris waSPS. This study shows that VOC‐induced priming targets a specific subset of JA‐inducible genes, and links these responses at the molecular level to enhanced levels of direct and indirect resistance against insect attack.
Childhood asthma and human leukocyte antigen type
Authors: Juhn Y. J. , Kita H. , Lee L. A. , Smith R. W. , Bagniewski S. M. , Weaver A. L. , Pankratz V. S. , Jacobson R. M. , Poland G. A. 
Published: November 2006

AbstractLittle is known about the relationship between human leukocyte antigen (HLA) class II genes and family history of asthma or atopy in relation to the incidence of childhood asthma. The objective of the study was to determine whether specific HLA class II genes (e.g., DRB1*03) are associated with asthma and whether such association explains the influences of family history of asthma or atopy on asthma incidence. A stratified random sample of 340 children who had HLA data available from the Rochester Family Measles Study cohort (n= 876) and a convenience sample of healthy children aged 5–12 years were the participants. We conducted comprehensive medical record reviews to determine asthma status of these children. The associations between the presence of specific HLA alleles and development of asthma and the role of family history of asthma or atopy in the association were evaluated by fitting Cox models. The cumulative incidence of asthma by 12 years of age among children who carry HLA DRB1*03 was 33%, compared to 24.2% among those who did not carry this allele. Adjusting for family history of asthma or atopy, gender, low birth weight, season of birth, HLA DRB1*04, and HLA DQB1*0302, the hazards ratio for HLA DRB1*03 carriers was 1.8 (95% confidence interval: 1.1–2.9, P= 0.020). We concluded that the HLA DRB1*03 allele is associated with asthma. However, the HLA class II gene does not explain the influences of family history of asthma or atopy on development of asthma. The mechanism underlying the association between asthma and HLA genes needs to be elucidated.
Bos indicus type of growth hormone receptor gene is retained in Japanese Black cattle
Authors: Ohkubo T. , Yano H. , Takahashi S. , Takahashi K. , Kimura N. , Tanaka M. 
Published: November 2006

SummaryThe growth hormone receptor (GHR) gene is responsible for growth and carcass traits, and polymorphisms associated with the variation of meat production are thought to occur in the liver‐specific promoter of the GHR gene in cattle. The aim of this study was to analyse the structure of the liver‐specific promoter of GHR in Japanese Black cattle, as the relationship between GHR polymorphism and meat production is poorly understood in this breed. Typically in European cattle, the LINE‐1 element, a family of retrotransposons, is inserted in the liver‐specific promoter. However, a short GHR promoter without the LINE‐1 sequence was found in the Japanese Black breed as in Bos indicus cattle. The frequency of the short allele was approximately 60%. In addition, 24 of 29 Holstein/Japanese Black crosses carried the short allele from their sire. The present result suggests that the short allele for GHR may be a candidate marker for improving meat production of Japanese Black cattle.
Species distribution and antifungal susceptibilities of dermatophytes during a one year period at a university hospital in Turkey
Authors: Ozkutuk Aydan , Ergon Cem , Yulug Nuran 
Published: November 2006

SummaryDermatophyte infections have been considered to be a major public health problem in many parts of the world. The aim of this study was to determine the causative agents of dermatophytoses and their antifungal susceptibilities in a Turkish University Hospital, west of Turkey. A total of 926 patients suspected to have dermatophytic lesions were examined over a period of 1 year (2001–2002). Samples collected from skin, hair and nails were submitted to direct microscopical examination using KOH and Calcofluor white stain, cultured on Sabouraud dextrose agar and Mycosel agar. The prevalence of dermatophytoses was 7.34% (68/926). Trichophyton rubrum was the most frequent dermatophyte isolated (56%) followed by T. mentagrophytes (38%), T. violaceum (1.5%), T. verrucosum (1.5%), Microsporum canis (1.5%) and Epidermophyton floccosum (1.5%). Tinea pedis (47%) was the most common type of infection, followed by tinea unguium (29%), tinea inguinalis (15%), tinea corporis (7.4%) and tinea capitis (1.6%). Secondary, we have tested 68 strains of dermatophytes against four antifungal agents following mainly the National Committee for Clinical Laboratory Standards M38‐P standard for filamentous fungi. In general, all antifungals were shown to be highly effective and itraconazole and naftifine appeared more active than ketoconazole and oxiconazole.