15 research outputs found

    Biomphalaria glabrata transcriptome: cDNA microarray profiling identifies resistant- and susceptible-specific gene expression in haemocytes from snail strains exposed to Schistosoma mansoni

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    BACKGROUND: Biomphalaria glabrata is an intermediate snail host for Schistosoma mansoni, one of the important schistosomes infecting man. B. glabrata/S. mansoni provides a useful model system for investigating the intimate interactions between host and parasite. Examining differential gene expression between S. mansoni-exposed schistosome-resistant and susceptible snail lines will identify genes and pathways that may be involved in snail defences. RESULTS: We have developed a 2053 element cDNA microarray for B. glabrata containing clones from ORESTES (Open Reading frame ESTs) libraries, suppression subtractive hybridization (SSH) libraries and clones identified in previous expression studies. Snail haemocyte RNA, extracted from parasite-challenged resistant and susceptible snails, 2 to 24 h post-exposure to S. mansoni, was hybridized to the custom made cDNA microarray and 98 differentially expressed genes or gene clusters were identified, 94 resistant-associated and 4 susceptible-associated. Quantitative PCR analysis verified the cDNA microarray results for representative transcripts. Differentially expressed genes were annotated and clustered using gene ontology (GO) terminology and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis. 61% of the identified differentially expressed genes have no known function including the 4 susceptible strain-specific transcripts. Resistant strain-specific expression of genes implicated in innate immunity of invertebrates was identified, including hydrolytic enzymes such as cathepsin L, a cysteine proteinase involved in lysis of phagocytosed particles; metabolic enzymes such as ornithine decarboxylase, the rate-limiting enzyme in the production of polyamines, important in inflammation and infection processes, as well as scavenging damaging free radicals produced during production of reactive oxygen species; stress response genes such as HSP70; proteins involved in signalling, such as importin 7 and copine 1, cytoplasmic intermediate filament (IF) protein and transcription enzymes such as elongation factor 1α and EF-2. CONCLUSION: Production of the first cDNA microarray for profiling gene expression in B. glabrata provides a foundation for expanding our understanding of pathways and genes involved in the snail internal defence system (IDS). We demonstrate resistant strain-specific expression of genes potentially associated with the snail IDS, ranging from signalling and inflammation responses through to lysis of proteinacous products (encapsulated sporocysts or phagocytosed parasite components) and processing/degradation of these targeted products by ubiquitination

    Can incontinence be cured? A systematic review of cure rates

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    Background Incontinence constitutes a major health problem affecting millions of people worldwide. The present study aims to assess cure rates from treating urinary (UI) or fecal incontinence (FI) and the number of people who may remain dependent on containment strategies. Methods Medline, Embase, PsycINFO, Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, and PEDro were searched from January 2005 to June 2015. Supplementary searches included conference abstracts and trials registers (2013–2015). Included studies had patients ≥ 18 years with UI or FI, reported treatment cure or success rates, had ≥ 50 patients treated with any intervention recognized in international guideline algorithms, a follow-up ≥ 3 months, and were published from 2005 onwards. Title and abstract screening, full paper screening, data extraction and risk-of-bias assessment were performed independently by two reviewers. Disagreements were resolved through discussion or referral to a third reviewer where necessary. A narrative summary of included studies is presented. Results Most evidence was found for UI: Surgical interventions for stress UI showed a median cure rate of 82.3% (interquartile range (IQR), 72–89.5%); people with urgency UI were mostly treated using medications (median cure rate for antimuscarinics = 49%; IQR, 35.6–58%). Pelvic floor muscle training and bulking agents showed lower cure rates for UI. Sacral neuromodulation for FI had a median cure rate of 38.6% (IQR, 35.6–40.6%). Conclusions Many individuals were not cured and hence may continue to rely on containment. No studies were found assessing success of containment strategies. There was a lack of data in the disabled and in those with neurological diseases, in the elderly and those with cognitive impairment. Surgical interventions were effective for stress UI. Other interventions for UI and FI showed lower cure rates. Many individuals are likely to be reliant on containment strategies

    Rift architecture and Caldera volcanism in the Taupo Volcanic Zone, New Zealand

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    The Taupo Volcanic Zone (TVZ) is investigated to determine the interaction of regional structure and volcanism. A three-tiered approach is employed involving (i) analysis of rift geometry and segmentation in Modem TVZ(<300 ka) from remote sensing and digital topographic data; (ii) fault kinematic data collected along the length of TVZ; and (iii) combining new and existing volcanological data for TVZ. Modem TVZ is a NNE-SSW trending intra-arc rift zone, subject to dextral transtension, and characterised by a segmented axial rift zone with a number of offset and variably oriented rift segments. These segments are subject to varying degrees of extension, and a general correlation exists between the amount of extension and the volume and style of volcanism in each segment. Segments with the highest degrees of extension correspond to the Okataina and Taupo Caldera Complexes in the central rhyolitic zone of Modem TVZ, while segments with a higher degree of dextral transtension correspond to the volumetrically-subordinate andesitic extremities. The influence of the structural framework on the shape and formation of calderas in Modem TVZ has been inferred from remote sensing and ground-based structural analysis. Detailed analysis of caldera structure and geometry in Modem TVZ indicates that caldera evolution is largely a function of caldera location relative to the axial rift zone. Calderas peripheral to the rift are simple, single-event structures, while those located within the axial rift zone are multiple-event caldera complexes with geometries dictated by their coincidence with rift faulting. These results show that in Modem TVZ the type, volume, and spatial distribution of magmatic activity is strongly influenced by rift structure and kinematics. The inter-relationship between rift geometry and caldera-complex development is particularly clear at the intra-rift Okataina Caldera Complex (OCC). OCC is located at a step-over in the rift where local rotation of the extension direction accompanies the development of a major transfer zone. Three main collapse events are spatially concentrated in a zone of orthogonal extension within the transfer zone. The 28 x 22 km OCC is elongate parallel to the extension direction, with a complicated topographic margin largely controlled by regional faulting. Major embayments occur on each side of OCC where it is intersected by adjacent rift segments. These are contiguous with two intra-caldera dome complexes forming two overlapping linear vent zones, which transect the caldera complex. The development of volcanism at OCC records the progressive interaction between offset rift segments and the propagation of overlapping rift segment axes. As rift propagation proceeded, a diffuse zone of volcanism progressively concentrated in the centre of the transfer zone then divided into two spatially restricted eruptive centres as through-going faults became established. Field investigations at OCC reveal a major revision to the eruptive stratigraphy that has implications for the development of the caldera and for hazard assessment in northern TVZ. Kawerau Ignimbrite is a partially welded pumice-rich ignimbrite that fills Puhipuhi Basin on the eastern side of the caldera complex and forms a thick terrace in and around the Kawerau township area. Within Puhipuhi Basin it is ~100 m thick, exposed on clear-felled knolls and locally forms jointed bluffs in thickest sections where it is valley ponded. Originally mapped as Kaingaroa Ignimbrite, it was subsequently considered distinct and renamed Kawerau Ignimbrite by Beresford & Cole (2000) with an accepted age of 240 ka. In Puhipuhi basin the Kawerau Ignimbrite overlies both the ~280 ka Matahina and ~65 ka Rotoiti ignimbrites and also the older tephras of the 43-31 ka Mangaone Subgroup. Whole-rock and glass geochemistry tie the ignimbrite specifically to the 33 ka Unit I eruptive phase of the subgroup, vastly increasing the eruptive volume of that unit and implying caldera collapse in this recent phase of OCC activity. Two pumice compositions are identified, reflecting eruption of two distinct magma bodies. Vertical variation in the ignimbrite records rapid depletion of a subordinate dacitic magma such that pumices of this composition are rare beyond proximal exposures. Lithic and pumice size distribution data indicate a source within OCC to the west of Puhipuhi basin. The residual volume of the ignimbrite is <15 km3, but estimates of the original volume approach 50 km3 when intra-caldera volumes are considered. Kawerau Ignimbrite thus represents the largest eruption from OCC in the last 65 ka since the Rotoiti event, and is the youngest partially-welded ignimbrite in TVZ

    Ionic electroactive polymer artificial muscles in space applications

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    A large-scale effort was carried out to test the performance of seven types of ionic electroactive polymer (IEAP) actuators in space-hazardous environmental factors in laboratory conditions. The results substantiate that the IEAP materials are tolerant to long-term freezing and vacuum environments as well as ionizing Gamma-, X-ray, and UV radiation at the levels corresponding to low Earth orbit (LEO) conditions. The main aim of this material behaviour investigation is to understand and predict device service time for prolonged exposure to space environment

    A continental phenology model for monitoring vegetation responses to interannual climatic variability

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    Regional phenology is important in ecosystem simulation models and coupled biosphere/atmosphere models. In the continental United States, the timing of the onset of greenness in the spring (leaf expansion, grass green-up) and offset of greenness in the fall (leaf abscission, cessation of height growth, grass brown-oft) are strongly influenced by meteorological and climatological conditions. We developed predictive phenology models based on traditional phenology research using commonly available meteorological and climatological data. Predictions were compared with satellite phenology observations at numerous 20 km x 20 km contiguous landcover sites. Onset mean absolute error was 7.2 days in the deciduous broadleaf forest (DBF) biome and 6.1 days in the grassland biome. Offset mean absolute error was 5.3 days in the DBF biome and 6.3 days in the grassland biome. Maximum expected errors at a 95 % probability level ranged from 10 to 14 days. Onset was strongly associated with temperature summations in both grassland and DBF biomes; DBF offset was best predicted with a photoperiod function, while grassland offset required a combination of precipitation and temperature controls. A long-term regional test of the DBF onset model captured field-measured interannual variability trends in lila
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