1,973 research outputs found
A standardised sampling protocol for robust assessment of reach-scale fish community diversity in wadeable New Zealand streams
The New Zealand fish fauna contains species that are affected not only by river system connectivity, but also by catchment and local-scale changes in landcover, water quality and habitat quality. Consequently, native fish have potential as multi-scale bioindicators of human pressure on stream ecosystems, yet no standardised, repeatable and scientifically defensible methods currently exist for effectively quantifying their abundance or diversity in New Zealand stream reaches. Here we report on the testing of a back-pack electrofishing method, modified from that used by the United States Environmental Protection Agency, on a wide variety of wadeable stream reaches throughout New Zealand. Seventy-three first- to third-order stream reaches were fished with a single pass over 150-345 m length. Time taken to sample a reach using single-pass electrofishing ranged from 1-8 h. Species accumulation curves indicated that, irrespective of location, continuous sampling of 150 stream metres is required to accurately describe reach-scale fish species richness using this approach. Additional species detection beyond 150 m was rare (<10%) with a single additional species detected at only two out of the 17 reaches sampled beyond this distance. A positive relationship was also evident between species detection and area fished, although stream length rather than area appeared to be the better predictor. The method tested provides a standardised and repeatable approach for regional and/or national reporting on the state of New Zealand's freshwater fish communities and trends in richness and abundance over time
Islet isolation assessment in man and large animals
Recent progress in islet isolation from the pancreas of large mammals including man, accentuated the need for the development of precise and reproducible techniques to assess islet yield. In this report both quantitative and qualitative criteria for islet isolation assessment were discussed, the main topics being the determination of number, volume, purity, morphologic integrity and in vitro and in vivo function tests of the final islet preparations. It has been recommended that dithizone should be used as a specific stain for immediate detection of islet tissue making it possible to estimate both the total number of islets (dividing them into classes of 50 μ diameter range increments) and the purity of the final preparation. Appropriate morphological assessment should include confirmation of islet identification, assessment of the morphological integrity and of the purity of the islet preparation. The use of fluorometric inclusion and exclusion dyes together have been suggested as a viability assay to simultaneously quantitate the proportion of cells that are intact or damaged. Perifusion of islets with glucose provides a dynamic profile of glucose-mediated insulin release and of the ability of the cells to down regulate insulin secretion after the glycemic challenge is interrupted. Although perifusion data provides a useful guide to islet viability the quantity and kinetics of insulin release do not necessarily predict islet performance after implantation. Therefore, the ultimate test of islet viability is their function after transplantation into a diabetic recipient. For this reason, in vivo models of transplantation of an aliquot of the final islet preparation into diabetic nude (athymic) rodents have been suggested. We hope that these general guidelines will be of assistance to standardize the assessment of islet isolations, making it possible to better interpret and compare procedures from different centers. © 1990 Casa Editrice il Ponte
Psychological impact, support and information needs for women with an abnormal Pap smear: comparative results of a questionnaire in three European countries
<p>Abstract</p> <p>Background</p> <p>Extensive information on cervical cancer is currently available. Its effectiveness in reducing anxiety in women receiving abnormal Pap tests is not clear. We investigated current practices of communicating abnormal Pap results to evaluate women's reactions and determine the sources of information they use subsequently.</p> <p>Methods</p> <p>A self-administered questionnaire-based study was performed in 1475 women in France, Spain and Portugal who had received an abnormal Pap smear result in the 12 months prior to completing the questionnaire. Questions covered methods of communication of the result, emotional reactions, support received (from the physician and entourage), and information sources, using pre-specified check box options and rating scales. Data were analyzed by country.</p> <p>Results</p> <p>Pap test results were mostly communicated by phone to Spanish women (76%), while physician letters were common in France (59%) and Portugal (36%). Frequent reactions were anxiety, panic and stress, which were less common in Spanish women than their French and Portuguese counterparts. After discussing with their physician, half of the participants were worried, despite rating highly the psychological support received. Over 90% of women in each country discussed their results with family or friends. Partners provided a high level of support. Overall, the abnormal diagnosis and consequences had a low to medium impact on daily, professional and family life and their relationships with their partner. Impact was higher in Spanish women than the French or Portuguese. Information on the diagnosis and its treatment was rated average, and nearly 80% of participants wanted more information, notably French women. Preferred sources were the physician and the Internet.</p> <p>Conclusions</p> <p>Women expressed a strong wish for more information about cervical cancer and other HPV-related diseases, and that their physician play a major role in its provision and in support. There was a heavy reliance on the close entourage and the Internet for information, highlighting the need for dissemination of accurate material. Differences between countries suggest information management strategies may need to be tailored to different geographical regions.</p
Psychosocial morbidity in women with abnormal cervical cytology managed by cytological surveillance or initial colposcopy:longitudinal analysis from the TOMBOLA randomised trial
Objective To compare psychosocial outcomes (follow-up related worries, and satisfaction with follow-up related information and support) over 30 months of two alternative management policies for women with low-grade abnormal cervical cytology.Methods Women aged 20-59 years with low grade cytological abnormalities detected in the NHS Cervical Screening Programme were randomised to cytological surveillance or initial colposcopy. 3399 women who completed psychosocial questionnaires at recruitment, were invited to complete questionnaires at 12, 18, 24 and 30 months. Linear mixed models were used to investigate differences between arms in the two psychosocial outcomes. Each outcome had a maximum score of 100 and higher scores represented higher psychosocial morbidity.Results On average, over 30 months women randomised to colposcopy scored 2.5 points (95%CI -3.6 to -1.3) lower for follow-up related worries than women randomised to cytological surveillance. Women in the colposcopy arm also scored significantly lower for follow-up related satisfaction with information and support (-2.4; -3.3 to -1.4) over 30 months. For both outcomes, the average difference between arms was greatest at 12 and 18 month time-points. These differences remained when the analysis was stratified by post-school education.Conclusions Women with low-grade cytology, irrespective of their management, have substantial initial psychosocial morbidity that reduces over time. Implementation of newer screening strategies which include surveillance, such as primary HPV screening, need to consider the information and support provided to women
Essential and checkpoint functions of budding yeast ATM and ATR during meiotic prophase are facilitated by differential phosphorylation of a meiotic adaptor protein, Hop1
A hallmark of the conserved ATM/ATR signalling is its ability to mediate a wide range of functions utilizing only a limited number of adaptors and effector kinases. During meiosis, Tel1 and Mec1, the budding yeast ATM and ATR, respectively, rely on a meiotic adaptor protein Hop1, a 53BP1/Rad9 functional analog, and its associated kinase Mek1, a CHK2/Rad53-paralog, to mediate multiple functions: control of the formation and repair of programmed meiotic DNA double strand breaks, enforcement of inter-homolog bias, regulation of meiotic progression, and implementation of checkpoint responses. Here, we present evidence that the multi-functionality of the Tel1/Mec1-to-Hop1/Mek1 signalling depends on stepwise activation of Mek1 that is mediated by Tel1/Mec1 phosphorylation of two specific residues within Hop1: phosphorylation at the threonine 318 (T318) ensures the transient basal level Mek1 activation required for viable spore formation during unperturbed meiosis. Phosphorylation at the serine 298 (S298) promotes stable Hop1-Mek1 interaction on chromosomes following the initial phospho-T318 mediated Mek1 recruitment. In the absence of Dmc1, the phospho-S298 also promotes Mek1 hyper-activation necessary for implementing meiotic checkpoint arrest. Taking these observations together, we propose that the Hop1 phospho-T318 and phospho-S298 constitute key components of the Tel1/Mec1- based meiotic recombination surveillance (MRS) network and facilitate effective coupling of meiotic recombination and progression during both unperturbed and challenged meiosis
The complete mitochondrial genome of the foodborne parasitic pathogen Cyclospora cayetanensis
Cyclospora cayetanensis is a human-specific coccidian parasite responsible for several food and water-related outbreaks around the world, including the most recent ones involving over 900 persons in 2013 and 2014 outbreaks in the USA. Multicopy organellar DNA such as mitochondrion genomes have been particularly informative for detection and genetic traceback analysis in other parasites. We sequenced the C. cayetanensis genomic DNA obtained from stool samples from patients infected with Cyclospora in Nepal using the Illumina MiSeq platform. By bioinformatically filtering out the metagenomic reads of non-coccidian origin sequences and concentrating the reads by targeted alignment, we were able to obtain contigs containing Eimeria-like mitochondrial, apicoplastic and some chromosomal genomic fragments. A mitochondrial genomic sequence was assembled and confirmed by cloning and sequencing targeted PCR products amplified from Cyclospora DNA using primers based on our draft assembly sequence. The results show that the C. cayetanensis mitochondrion genome is 6274 bp in length, with 33% GC content, and likely exists in concatemeric arrays as in Eimeria mitochondrial genomes. Phylogenetic analysis of the C. cayetanensis mitochondrial genome places this organism in a tight cluster with Eimeria species. The mitochondrial genome of C. cayetanensis contains three protein coding genes, cytochrome (cytb), cytochrome C oxidase subunit 1 (cox1), and cytochrome C oxidase subunit 3 (cox3), in addition to 14 large subunit (LSU) and nine small subunit (SSU) fragmented rRNA genes
Antisense DNA parameters derived from next-nearest-neighbor analysis of experimental data
<p>Abstract</p> <p>Background</p> <p>The enumeration of tetrameric and other sequence motifs that are positively or negatively correlated with <it>in vivo </it>antisense DNA effects has been a useful addition to the arsenal of information needed to predict effective targets for antisense DNA control of gene expression. Such retrospective information derived from <it>in vivo </it>cellular experiments characterizes aspects of the sequence dependence of antisense inhibition that are not predicted by nearest-neighbor (NN) thermodynamic parameters derived from <it>in vitro </it>experiments. However, quantitation of the antisense contributions of motifs is problematic, since individual motifs are not isolated from the effects of neighboring nucleotides, and motifs may be overlapping. These problems are circumvented by a next-nearest-neighbor (NNN) analysis of antisense DNA effects in which the overlapping nature of nearest-neighbors is taken into account.</p> <p>Results</p> <p>Next-nearest-neighbor triplet combinations of nucleotides are the simplest that include overlapping sequence effects and therefore can encompass interactions beyond those of nearest neighbors. We used singular value decomposition (SVD) to fit experimental data from our laboratory in which phosphorothioate-modified antisense DNAs (S-DNAs) 20 nucleotides long were used to inhibit cellular protein expression in 112 experiments involving four gene targets and two cell lines. Data were fitted using a NNN model, neglecting end effects, to derive NNN inhibition parameters that could be combined to give parameters for a set of 49 sequences that represents the inhibitory effects of all possible overlapping triplet interactions in the cellular targets of these antisense S-DNAs. We also show that parameters to describe subsets of the data, such as the mRNAs being targeted and the cell lines used, can be included in such a derivation. While NNN triplet parameters provided an adequate model to fit our data, NN doublet parameters did not.</p> <p>Conclusions</p> <p>The methodology presented illustrates how NNN antisense inhibitory information can be derived from <it>in vivo </it>cellular experiments. Subsequent calculations of the antisense inhibitory parameters for any mRNA target sequence automatically take into account the effects of all possible overlapping combinations of nearest-neighbors in the sequence. This procedure is more robust than the tallying of tetrameric motifs that have positive or negative antisense effects. The specific parameters derived in this work are limited in their applicability by the relatively small database of experiments that was used in their derivation.</p
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