7,876 research outputs found

    Evaluating Multiple Arthropod Taxa as Indicators of Invertebrate Diversity in Old Fields

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    Biodiversity, often quantified by species richness, is commonly used to evaluate and monitor the health of ecosystems and as a tool for conservation planning. The use of one or more focal taxa as surrogates or indicators of larger taxonomic diversity can greatly expedite the process of biodiversity measurement. This is especially true when studying diverse and abundant invertebrate fauna. Before indicator taxa are employed, however, research into their suitability as indicators of greater taxonomic diversity in an area is needed. We sampled invertebrate diversity in old fields in southern Michigan using pitfall trapping and morphospecies designations after identification to order or family. Correlation analysis was used to assess species richness relationships between focal arthropod taxa and general invertebrate diversity. Relationships were assessed at two fine spatial scales: within sampling patches, and locally across four sampling patches. Cumulative richness of all assessed taxa increased proportionately with cumulative invertebrate richness as sampling intensity increased within patches. At the among-patch scale, we tentatively identified Hemiptera and Coleoptera as effective indicator taxa of greater invertebrate richness. Although Hymenoptera, Araneae and Diptera exhibited high species richness, their total richness within patches was not associated with overall invertebrate richness among patches. Increased sampling throughout the active season and across a greater number of habitat patches should be conducted before adopting Hemiptera and Coleoptera as definitive indicators of general invertebrate richness in the Great Lakes region. Multiple sampling techniques, in addition to pitfall trapping, should also be added to overcome capture biases associated with each technique

    Novel mutations in the BRCA1 and BRCA2 genes in Iranian women with early-onset breast cancer

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    BACKGROUND: Breast cancer is the most common female malignancy and a major cause of death in middle-aged women. So far, germline mutations in the BRCA1 and BRCA2 genes in patients with early-onset breast and/or ovarian cancer have not been identified within the Iranian population. METHODS: With the collaboration of two main centres for cancer in Iran, we obtained clinical information, family history and peripheral blood from 83 women under the age of 45 with early-onset breast cancer for scanning of germline mutations in the BRCA1 and BRCA2 genes. We analysed BRCA1 exons 11 and BRCA2 exons 10 and 11 by the protein truncation test, and BRCA1 exons 2, 3, 5, 13 and 20 and BRCA2 exons 9, 17, 18 and 23 with the single-strand conformation polymorphism assay on genomic DNA amplified by polymerase chain reaction. RESULTS: Ten sequence variants were identified: five frameshifts (putative mutations – four novel); three missense changes of unknown significance and two polymorphisms, one seen commonly in both Iranian and British populations. CONCLUSIONS Identification of these novel mutations suggests that any given population should develop a mutation database for its programme of breast cancer screening. The pattern of mutations seen in the BRCA genes seems not to differ from other populations studied. Early-onset breast cancer (less than 45 years) and a limited family history is sufficient to justify mutation screening with a detection rate of over 25% in this group, whereas sporadic early-onset breast cancer (detection rate less than 5%) is unlikely to be cost-effective

    Regulation of vascular endothelial growth factor bioactivity in patients with acute lung injury

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    Background: Reduced bioactive vascular endothelial growth factor (VEGF) has been demonstrated in several inflammatory lung conditions including the acute respiratory distress syndrome (ARDS). sVEGFR-1, a soluble form of VEGF-1 receptor, is a potent natural inhibitor of VEGF. We hypothesised that sVEGFR-1 plays an important role in the regulation of the bioactivity of VEGF within the lung in patients with ARDS. Methods: Forty one patients with ARDS, 12 at risk of developing ARDS, and 16 normal controls were studied. Bioactive VEGF, total VEGF, and sVEGFR-1 were measured by ELISA in plasma and bronchoalveolar lavage (BAL) fluid. Reverse transcriptase polymerase chain reaction for sVEGFR-1 was performed on BAL cells. Results: sVEGFR-1 was detectable in the BAL fluid of 48% (20/41) of patients with early ARDS (1.4– 54.8 ng/ml epithelial lining fluid (ELF)) compared with 8% (1/12) at risk patients (p = 0.017) and none of the normal controls (p = 0.002). By day 4 sVEGFR-1 was detectable in only 2/18 ARDS patients (p = 0.008). Patients with detectable sVEGFR-1 had lower ELF median (IQR) levels of bioactive VEGF than those without detectable sVEGFR-1 (1415.2 (474.9–3192) pg/ml v 4761 (1349–7596.6) pg/ml, median difference 3346 pg/ml (95% CI 305.1 to 14711.9), p = 0.016), but there was no difference in total VEGF levels. BAL cells expressed mRNA for sVEGFR-1 and produced sVEGFR-1 protein which increased following incubation with tumour necrosis factor a. Conclusion: This study shows for the first time the presence of sVEGFR-1 in the BAL fluid of patients with ARDS. This may explain the presence of reduced bioactive VEGF in patients early in the course of ARDS

    Demographic characteristics of exploited tropical lutjanids: a comparative analysis

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    Demographic parameters from seven exploited coral reef lutjanid species were compared as a case study of the implications of intrafamily variation in life histories for multispecies harvest management. Modal lengths varied by 4 cm among four species (Lutjanus fulviflamma, L. vitta, L. carponotatus, L. adetii), which were at least 6 cm smaller than the modal lengths of the largest species (L. gibbus, Symphorus nematophorus, Aprion virescens). Modal ages, indicating ages of full selection to fishing gear, were 10 years or less for all species, but maximum ages ranged from 12 (L. gibbus) to 36 years (S. nematophorus). Each species had a unique growth pattern, with differences in length-at-age and mean asymptotic fork length (L∞), but smaller species generally grew fast during the first 1–2 years of life and larger species grew more slowly over a longer period. Total mortality rates varied among species; L. gibbus had the highest mortality and L. fulviflamma, the lowest mortality. The variability in life history strategies of these tropical lutjanids makes generalizations about lutjanid life histories difficult, but the fact that all seven had characteristics that would make them particularly vulnerable to fishing indicates that harvest of tropical lutjanids should be managed with caution
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