96 research outputs found

    Geomorphic patterns, internal architecture and reef growth in a macrotidal, high-turbidity setting of coral reefs from the Kimberley bioregion

    Get PDF
    The coral reefs of the Kimberley bioregion are situated in an area that is considered a significant ‘biodiversity hotspot’ and are poorly known and of recognised international significance. This paper is a review of ongoing research as part of one of the first geoscientific reef studies of the Kimberley Biozone. Remote sensing, sub-bottom profiling and associated sedimentological work have been employed to produce a regional geodatabase of coral reefs and determine the Holocene internal architecture and growth history of the coral reefs. Satellite image analysis has revealed that fringing reefs in the Kimberley bioregion grow very well and differ geomorphologically from planar reefs both inshore and offshore. The acoustic profiles have depicted multiple reef build-ups, demonstrating the reefs’ long-term resilience. This research has provided a better understanding of the Kimberley reefs and demonstrated their capacity to succeed in challenging environments and generate habitats characterised by high complexity and species diversity

    Loss and re-adaptation of lumbar intervertebral disc water signal intensity after prolonged bedrest

    Full text link
    © 2015, International Society of Musculoskeletal and Neuronal Interactions. All right reserved. The adaptation and re-adaptation process of the intervertebral disc (IVD) to prolonged bedrest is important for understanding IVD physiology and IVD herniations in astronauts. Little information is available on changes in IVD composition. In this study, 24 male subjects underwent 60-day bedrest and In/Out Phase magnetic resonance imaging sequences were performed to evaluate IVD shape and water signal intensity. Scanning was performed before bedrest (baseline), twice during bedrest, and three, six and twenty-four months after bedrest. Area, signal intensity, average height, and anteroposterior diameter of the lumbar L3/4 and L4/5 IVDs were measured. At the end of bedrest, disc height and area were significantly increased with no change in water signal intensity. After bedrest, we observed reduced IVD signal intensity three months (p=0.004 versus baseline), six months (p=0.003 versus baseline), but not twenty-four months (p=0.25 versus baseline) post-bedrest. At these same time points post-bedrest, IVD height and area remained increased. The reduced lumbar IVD water signal intensity in the first months after bedrest implies a reduction of glycosaminoglycans and/or free water in the IVD. Subsequently, at two years after bedrest, IVD hydration status returned towards pre-bedrest levels, suggesting a gradual, but slow, re-adaptation process of the IVD after prolonged bedrest

    A single gene defect causing claustrophobia

    Get PDF
    Claustrophobia, the well-known fear of being trapped in narrow/closed spaces, is often considered a conditioned response to traumatic experience. Surprisingly, we found that mutations affecting a single gene, encoding a stress-regulated neuronal protein, can cause claustrophobia. Gpm6a-deficient mice develop normally and lack obvious behavioral abnormalities. However, when mildly stressed by single-housing, these mice develop a striking claustrophobia-like phenotype, which is not inducible in wild-type controls, even by severe stress. The human GPM6A gene is located on chromosome 4q32-q34, a region linked to panic disorder. Sequence analysis of 115 claustrophobic and non-claustrophobic subjects identified nine variants in the noncoding region of the gene that are more frequent in affected individuals (P=0.028). One variant in the 3′untranslated region was linked to claustrophobia in two small pedigrees. This mutant mRNA is functional but cannot be silenced by neuronal miR124 derived itself from a stress-regulated transcript. We suggest that loosing dynamic regulation of neuronal GPM6A expression poses a genetic risk for claustrophobia

    Recurrent flares in active region NOAA 11283

    Get PDF
    Context. Flares and coronal mass ejections (CMEs) are solar phenomena that are not yet fully understood. Several investigations have been performed to single out their related physical parameters that can be used as indices of the magnetic complexity leading to their occurrence. Aims. In order to shed light on the occurrence of recurrent flares and subsequent associated CMEs, we studied the active region NOAA 11283 where recurrent M and X GOES-class flares and CMEs occurred. Methods. We use vector magnetograms taken by HMI/SDO to calculate the horizontal velocity fields of the photospheric magnetic structures, the shear and the dip angles of the magnetic field, the magnetic helicity flux distribution, and the Poynting fluxes across the photosphere due to the emergence and the shearing of the magnetic field. Results. Although we do not observe consistent emerging magnetic flux through the photosphere during the observation time interval, we detected a monotonic increase of the magnetic helicity accumulated in the corona. We found that both the shear and the dip angles have high values along the main polarity inversion line (PIL) before and after all the events. We also note that before the main flare of X2.1 GOES class, the shearing motions seem to inject a more significant energy than the energy injected by the emergence of the magnetic field. Conclusions. We conclude that the very long duration (about 4 days) of the horizontal displacement of the main photospheric magnetic structures along the PIL has a primary role in the energy release during the recurrent flares. This peculiar horizontal velocity field also contributes to the monotonic injection of magnetic helicity into the corona. This process, coupled with the high shear and dip angles along the main PIL, appears to be responsible for the consecutive events of loss of equilibrium leading to the recurrent flares and CMEs

    Utilization and responsiveness of the asthma control test (ACT) at the initiation of therapy for patients with asthma: a randomized controlled trial

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to assess the responsiveness of the asthma control test (ACT) to detect changes at the initiation of therapy and its utilization in the initiation of asthma treatment.</p> <p>Methods</p> <p>This study was designed as a randomized clinical trial conducted in a primary care setting. The subjects were asthma patients who had not received controller therapy for at least two months. The patients were randomized into two groups: The Saudi Initiative for Asthma (SINA) group and the Global Initiative for Asthma (GINA) group. Treatment in the SINA group was initiated at step1 when the ACT scores ≥ 20, step 2 when the score between16-19, and step 3 when the score < 16 began at step 3. The GINA group patients were started on step 2 when they had persistent asthma symptoms or step 3 when they had severely uncontrolled disease.</p> <p>Results</p> <p>Forty-five patients were analyzed in each group. The improvement in ACT score after treatment initiation was significantly higher when the SINA approach was used (2.9 in the SINA group compared to 1.7 in the GINA group (<it>p </it>= 0.04)). The improvement in FEV<sub>1 </sub>was 5.8% in the SINA group compared to 3.4% in the GINA group (<it>p </it>= 0.46). The number of patients who achieved asthma control at the follow-up visit and required no treatment adjustment was 33 (73.3%) in the SINA group and 27 (60%) in the GINA group (<it>p </it>= 0.0125).</p> <p>Conclusion</p> <p>The ACT was responsive to change at the initiation of asthma treatment and was useful for the initiation of asthma treatment.</p> <p>Trial Registration number</p> <p><a href="http://www.controlled-trials.com/ISRCTN31998214">ISRCTN31998214</a></p

    Mimicry and well known genetic friends: molecular diagnosis in an Iranian cohort of suspected Bartter syndrome and proposition of an algorithm for clinical differential diagnosis.

    Get PDF
    BACKGROUND: Bartter Syndrome is a rare, genetically heterogeneous, mainly autosomal recessively inherited condition characterized by hypochloremic hypokalemic metabolic alkalosis. Mutations in several genes encoding for ion channels localizing to the renal tubules including SLC12A1, KCNJ1, BSND, CLCNKA, CLCNKB, MAGED2 and CASR have been identified as underlying molecular cause. No genetically defined cases have been described in the Iranian population to date. Like for other rare genetic disorders, implementation of Next Generation Sequencing (NGS) technologies has greatly facilitated genetic diagnostics and counseling over the last years. In this study, we describe the clinical, biochemical and genetic characteristics of patients from 15 Iranian families with a clinical diagnosis of Bartter Syndrome. RESULTS: Age range of patients included in this study was 3 months to 6 years and all patients showed hypokalemic metabolic alkalosis. 3 patients additionally displayed hypercalciuria, with evidence of nephrocalcinosis in one case. Screening by Whole Exome Sequencing (WES) and long range PCR revealed that 12/17 patients (70%) had a deletion of the entire CLCNKB gene that was previously identified as the most common cause of Bartter Syndrome in other populations. 4/17 individuals (approximately 25% of cases) were found to suffer in fact from pseudo-Bartter syndrome resulting from congenital chloride diarrhea due to a novel homozygous mutation in the SLC26A3 gene, Pendred syndrome due to a known homozygous mutation in SLC26A4, Cystic Fibrosis (CF) due to a novel mutation in CFTR and apparent mineralocorticoid excess syndrome due to a novel homozygous loss of function mutation in HSD11B2 gene. 1 case (5%) remained unsolved. CONCLUSIONS: Our findings demonstrate deletion of CLCNKB is the most common cause of Bartter syndrome in Iranian patients and we show that age of onset of clinical symptoms as well as clinical features amongst those patients are variable. Further, using WES we were able to prove that nearly 1/4 patients in fact suffered from Pseudo-Bartter Syndrome, reversing the initial clinical diagnosis with important impact on the subsequent treatment and clinical follow up pathway. Finally, we propose an algorithm for clinical differential diagnosis of Bartter Syndrome

    The effect of resistance training interventions on weight status in youth:a meta-analysis

    Get PDF
    Abstract Background There has been a rise in research into obesity prevention and treatment programmes in youth, including the effectiveness of resistance-based exercise. The purpose of this meta-analysis was to examine the effect of resistance training interventions on weight status in youth. Methods Meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered on PROSPERO (registration number CRD42016038365). Eligible studies were from English language peer-reviewed published articles. Searches were conducted in seven databases between May 2016 and June 2017. Studies were included that examined the effect of resistance training on weight status in youth, with participants of school age (5–18 years). Results There were 24 complete sets of data from 18 controlled trials (CTs) which explored 8 outcomes related to weight status. Significant, small effect sizes were identified for body fat% (Hedges’ g = 0.215, 95% CI 0.059 to 0.371, P = 0.007) and skinfolds (Hedges’ g = 0.274, 95% CI 0.066 to 0.483, P = 0.01). Effect sizes were not significant for: body mass (Hedges’ g = 0.043, 95% CI − 0.103 to 0.189, P = 0.564), body mass index (Hedges’ g = 0.024, 95% CI − 0.205 to 0.253, P = 0.838), fat-free mass (Hedges’ g = 0.073, 95% CI − 0.169 to 0.316, P = 0.554), fat mass (Hedges’ g = 0.180, 95% CI − 0.090 to 0.451, P = 0.192), lean mass (Hedges’ g = 0.089, 95% CI − 0.122 to 0.301, P = 0.408) or waist circumference (Hedges’ g = 0.209, 95% CI − 0.075 to 0.494, P = 0.149). Conclusions The results of this meta-analysis suggest that an isolated resistance training intervention may have an effect on weight status in youth. Overall, more quality research should be undertaken to investigate the impact of resistance training in youth as it could have a role to play in the treatment and prevention of obesity

    Role of DNA methylation in head and neck cancer

    Get PDF
    Head and neck cancer (HNC) is a heterogenous and complex entity including diverse anatomical sites and a variety of tumor types displaying unique characteristics and different etilogies. Both environmental and genetic factors play a role in the development of the disease, but the underlying mechanism is still far from clear. Previous studies suggest that alterations in the genes acting in cellular signal pathways may contribute to head and neck carcinogenesis. In cancer, DNA methylation patterns display specific aberrations even in the early and precancerous stages and may confer susceptibility to further genetic or epigenetic changes. Silencing of the genes by hypermethylation or induction of oncogenes by promoter hypomethylation are frequent mechanisms in different types of cancer and achieve increasing diagnostic and therapeutic importance since the changes are reversible. Therefore, methylation analysis may provide promising clinical applications, including the development of new biomarkers and prediction of the therapeutic response or prognosis. In this review, we aimed to analyze the available information indicating a role for the epigenetic changes in HNC

    Physiological and anthropometric determinants of critical power, W ′ and the reconstitution of W ′ in trained and untrained male cyclists

    Get PDF
    From Springer Nature via Jisc Publications RouterHistory: received 2020-01-17, accepted 2020-07-31, registration 2020-08-01, pub-electronic 2020-08-09, online 2020-08-09, pub-print 2020-11Publication status: PublishedAbstract: Purpose: This study examined the relationship of physiological and anthropometric characteristics with parameters of the critical power (CP) model, and in particular the reconstitution of W′ following successive bouts of maximal exercise, amongst trained and untrained cyclists. Methods: Twenty male adults (trained nine; untrained 11; age 39 ± 15 year; mass 74.7 ± 8.7 kg; V̇O2max 58.0 ± 8.7 mL kg−1 min−1) completed three incremental ramps (20 W min−1) to exhaustion interspersed with 2-min recoveries. Pearson’s correlation coefficients were used to assess relationships for W′ reconstitution after the first recovery (W′rec1), the delta in W′ reconstituted between recoveries (∆W′rec), CP and W′. Results: CP was strongly related to V̇O2max for both trained (r = 0.82) and untrained participants (r = 0.71), whereas W′ was related to V̇O2max when both groups were considered together (r = 0.54). W′rec1 was strongly related to V̇O2max for the trained (r = 0.81) but not untrained (r = 0.18); similarly, ∆W′rec was strongly related to V̇O2max (r = − 0.85) and CP (r = − 0.71) in the trained group only. Conclusions: Notable physiological relationships between parameters of aerobic fitness and the measurements of W′ reconstitution were observed, which differed among groups. The amount of W′ reconstitution and the maintenance of W′ reconstitution that occurred with repeated bouts of maximal exercise were found to be related to key measures of aerobic fitness such as CP and V̇O2max. This data demonstrates that trained cyclists wishing to improve their rate of W′ reconstitution following repeated efforts should focus training on improving key aspects of aerobic fitness such as V̇O2max and CP

    Astrophysics in 2005

    Get PDF
    We bring you, as usual, the Sun and Moon and stars, plus some galaxies and a new section on astrobiology. Some highlights are short (the newly identified class of gamma-ray bursts, and the Deep Impact on Comet 9P/ Tempel 1), some long (the age of the universe, which will be found to have the Earth at its center), and a few metonymic, for instance the term "down-sizing" to describe the evolution of star formation rates with redshift
    corecore