122 research outputs found

    Downscaling extremes: A comparison of extreme value distributions in point-source and gridded precipitation data

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    There is substantial empirical and climatological evidence that precipitation extremes have become more extreme during the twentieth century, and that this trend is likely to continue as global warming becomes more intense. However, understanding these issues is limited by a fundamental issue of spatial scaling: most evidence of past trends comes from rain gauge data, whereas trends into the future are produced by climate models, which rely on gridded aggregates. To study this further, we fit the Generalized Extreme Value (GEV) distribution to the right tail of the distribution of both rain gauge and gridded events. The results of this modeling exercise confirm that return values computed from rain gauge data are typically higher than those computed from gridded data; however, the size of the difference is somewhat surprising, with the rain gauge data exhibiting return values sometimes two or three times that of the gridded data. The main contribution of this paper is the development of a family of regression relationships between the two sets of return values that also take spatial variations into account. Based on these results, we now believe it is possible to project future changes in precipitation extremes at the point-location level based on results from climate models.Comment: Published in at http://dx.doi.org/10.1214/09-AOAS287 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Contemporary Approach to Narrow Angles

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    Glaucoma is the leading cause of irreversible blindness worldwide. Among all glaucoma types, primary angle closure glaucoma (PACG) affects approximately 23 million people worldwide, and is responsible for 50% of glaucoma-related blindness, highlighting the devastating consequences of this disease. The main mechanism of PACG is relative pupillary block. High-risk populations are female gender, Asian ethnicity, high hyperopia, short axial length, and a thick/anteriorly positioned lens. This review discusses the clinical diagnosis, classification, and management of patients with a narrow angle with and without intraocular pressure (IOP) elevation and glaucomatous optic nerve damage, including laser peripheral iridotomy (LPI), endocycloplasty (ECPL), lens extraction, and goniosynechialysis

    Effect of Phacoemulsification on Intraocular Pressure in Eyes with Functioning Tube Shunts

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    Purpose: To evaluate the effect of phacoemulsification on intraocular pressure (IOP) in eyes with functioning tube shunts. Methods: This was a retrospective chart review of primary open-angle glaucoma (POAG) patients with a functioning tube who underwent phacoemulsification and had ≥24 months of follow-up. The primary end point was defined as surgical failure (IOP > 21 mmHg) at month 24, progression to no light perception (NLP) vision, glaucoma reoperation, or implant removal. Surgical failure defined as IOP >18 and >15 mmHg, changes in visual acuity (VA), IOP, and number of medications were assessed. Results: Twenty-seven eyes of 27 patients with moderate or severe POAG were included. The mean age of the patients was 64.2 ± 10.8 years. The interval between the tube shunt and phacoemulsification was 28.8 ± 25.0 months. At the end of the study, four (14.8%) eyes met the failure criteria; the average time to failure was 9.3 ± 3.8 months. The causes of failure were high IOP in two (50.0%) and glaucoma reoperation in two (50.0%) eyes; however, no eyes progressed to NLP vision. Surgical failure defined as IOP >18 and >15 mmHg showed an increasing failure rate (18.5% and 48.5%, respectively). The mean IOP and medications number remained stable at month 24 compared to baseline (P = 0.131 and P = 0.302, respectively). Initially, VA showed improvement, with the greatest improvement at 6 months (P = 0.001), but at 24 months the improvement was no longer significant (P = 0.430). Conclusion: Phacoemulsification in patients with functioning tubes did not change the mean IOP in most of the patients (86.2%); the number of medications also did not increase

    Next generation sequencing of chromosomal rearrangements in patients with split-hand/split-foot malformation provides evidence for DYNC1I1 exonic enhancers of DLX5/6 expression in humans

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    This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this recordSplit-hand/foot malformation type 1 is an autosomal dominant condition with reduced penetrance and variable expression. We report three individuals from two families with split-hand/split-foot malformation (SHFM) in whom next generation sequencing was performed to investigate the cause of their phenotype.Wellcome Trus

    Effect of Phacoemulsification on Intraocular Pressure in Eyes With Functioning Tube Shunts

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    Purpose: To evaluate the effect of phacoemulsification on intraocular pressure (IOP) in eyes with functioning tube shunts. Methods: This was a retrospective chart review of primary open-angle glaucoma (POAG) patients with a functioning tube who underwent phacoemulsification and had ≥24 months of follow-up. The primary end point was defined as surgical failure (IOP \u3e 21 mmHg) at month 24, progression to no light perception (NLP) vision, glaucoma reoperation, or implant removal. Surgical failure defined as IOP \u3e18 and \u3e15 mmHg, changes in visual acuity (VA), IOP, and number of medications were assessed. Results: Twenty-seven eyes of 27 patients with moderate or severe POAG were included. The mean age of the patients was 64.2 ± 10.8 years. The interval between the tube shunt and phacoemulsification was 28.8 ± 25.0 months. At the end of the study, four (14.8%) eyes met the failure criteria; the average time to failure was 9.3 ± 3.8 months. The causes of failure were high IOP in two (50.0%) and glaucoma reoperation in two (50.0%) eyes; however, no eyes progressed to NLP vision. Surgical failure defined as IOP \u3e18 and \u3e15 mmHg showed an increasing failure rate (18.5% and 48.5%, respectively). The mean IOP and medications number remained stable at month 24 compared to baseline (P = 0.131 and P = 0.302, respectively). Initially, VA showed improvement, with the greatest improvement at 6 months (P = 0.001), but at 24 months the improvement was no longer significant (P = 0.430). Conclusion: Phacoemulsification in patients with functioning tubes did not change the mean IOP in most of the patients (86.2%); the number of medications also did not increase

    On tail trend detection: modeling relative risk

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    The climate change dispute is about changes over time of environmental characteristics (such as rainfall). Some people say that a possible change is not so much in the mean but rather in the extreme phenomena (that is, the average rainfall may not change much but heavy storms may become more or less frequent). The paper studies changes over time in the probability that some high threshold is exceeded. The model is such that the threshold does not need to be specified, the results hold for any high threshold. For simplicity a certain linear trend is studied depending on one real parameter. Estimation and testing procedures (is there a trend?) are developed. Simulation results are presented. The method is applied to trends in heavy rainfall at 18 gauging stations across Germany and The Netherlands. A tentative conclusion is that the trend seems to depend on whether or not a station is close to the sea.Comment: 38 page

    SLC4A10 mutation causes a neurological disorder associated with impaired GABAergic transmission

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    SLC4A10 is a plasma-membrane bound transporter which utilizes the Na+ gradient to drive cellular HCO3- uptake, thus mediating acid extrusion. In the mammalian brain, SLC4A10 is expressed in principal neurons and interneurons, as well as in epithelial cells of the choroid plexus, the organ regulating the production of cerebrospinal fluid. Using next generation sequencing on samples from five unrelated families encompassing ten affected individuals, we show that biallelic SLC4A10 loss-of-function variants cause a clinically recognizable neurodevelopmental disorder in humans. The cardinal clinical features of the condition include hypotonia in infancy, delayed psychomotor development across all domains and typically severe intellectual impairment. Affected individuals commonly display traits associated with autistic spectrum disorders including anxiety, hyperactivity and stereotyped movements. In two cases isolated episodes of seizures were reported in the first few years of life, and a further affected child displayed bitemporal epileptogenic discharges on EEG without overt clinical seizures. While occipitofrontal circumference was reported to be normal at birth, progressive postnatal microcephaly evolved in 7 out of 10 affected individuals. Neuroradiological features included a relative preservation of brain volume compared to occipitofrontal circumference, characteristic narrow sometimes 'slit-like' lateral ventricles and corpus callosum abnormalities. Slc4a10 -/- mice, deficient for SLC4A10, also display small lateral brain ventricles and mild behavioral abnormalities including delayed habituation and alterations in the 2-object novel object recognition task. Collapsed brain ventricles in both Slc4a10-/- mice and affected individuals suggests an important role of SLC4A10 in the production of the cerebrospinal fluid. However, it is notable that despite diverse roles of the cerebrospinal fluid in the developing and adult brain, the cortex of Slc4a10-/- mice appears grossly intact. Co-staining with synaptic markers revealed that in neurons, SLC4A10 localizes to inhibitory, but not excitatory, presynapses. These findings are supported by our functional studies which show the release of the inhibitory neurotransmitter GABA is compromised in Slc4a10-/- mice, while the release of the excitatory neurotransmitter glutamate is preserved. Manipulation of intracellular pH partially rescues GABA release. Together our studies define a novel characteristic neurodevelopmental disorder associated with biallelic pathogenic variants in SLC4A10 and highlight the importance of further analyses of the consequences of SLC4A10 loss-of-function for brain development, synaptic transmission and network properties

    ACBD5 and VAPB mediate membrane associations between peroxisomes and the ER

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    This is the final version of the article. Available from the publisher via the DOI in this record.Peroxisomes (POs) and the endoplasmic reticulum (ER) cooperate in cellular lipid metabolism and form tight structural associations, which were first observed in ultrastructural studies decades ago. PO–ER associations have been suggested to impact on a diverse number of physiological processes, including lipid metabolism, phospholipid exchange, metabolite transport, signaling, and PO biogenesis. Despite their fundamental importance to cell metabolism, the mechanisms by which regions of the ER become tethered to POs are unknown, in particular in mammalian cells. Here, we identify the PO membrane protein acyl-coenzyme A–binding domain protein 5 (ACBD5) as a binding partner for the resident ER protein vesicle-associated membrane protein-associated protein B (VAPB). We show that ACBD5–VAPB interaction regulates PO–ER associations. Moreover, we demonstrate that loss of PO–ER association perturbs PO membrane expansion and increases PO movement. Our findings reveal the first molecular mechanism for establishing PO–ER associations in mammalian cells and report a new function for ACBD5 in PO–ER tethering.This work was supported by grants from the Biotechnology and Biological Sciences Research Council (BB/K006231/1 and BB/ N01541X/1 to M. Schrader). J. Metz and M. Schrader are supported by a Wellcome Trust Institutional Strategic Support Award (WT097835MF and WT105618MA) and L.F. Godinho by a fellowship from Fundação para a Ciência e a Tecnologia, Portugal (SFRH/ BPD/90084/2012). M. Schrader and A.S. Azadi are supported by Marie Curie Initial Training Network action PerFuMe (316723). M. Islinger is supported by MEAMEDMA Anschubförderung, Medical Faculty Mannheim, University of Heidelberg

    Mitochondrial oxodicarboxylate carrier deficiency is associated with mitochondrial DNA depletion and spinal muscular atrophy-like disease.

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    PURPOSE: To understand the role of the mitochondrial oxodicarboxylate carrier (SLC25A21) in the development of spinal muscular atrophy-like disease. METHODS: We identified a novel pathogenic variant in a patient by whole-exome sequencing. The pathogenicity of the mutation was studied by transport assays, computer modeling, followed by targeted metabolic testing and in vitro studies in human fibroblasts and neurons. RESULTS: The patient carries a homozygous pathogenic variant c.695A>G; p.(Lys232Arg) in the SLC25A21 gene, encoding the mitochondrial oxodicarboxylate carrier, and developed spinal muscular atrophy and mitochondrial myopathy. Transport assays show that the mutation renders SLC25A21 dysfunctional and 2-oxoadipate cannot be imported into the mitochondrial matrix. Computer models of central metabolism predicted that impaired transport of oxodicarboxylate disrupts the pathways of lysine and tryptophan degradation, and causes accumulation of 2-oxoadipate, pipecolic acid, and quinolinic acid, which was confirmed in the patient's urine by targeted metabolomics. Exposure to 2-oxoadipate and quinolinic acid decreased the level of mitochondrial complexes in neuronal cells (SH-SY5Y) and induced apoptosis. CONCLUSION: Mitochondrial oxodicarboxylate carrier deficiency leads to mitochondrial dysfunction and the accumulation of oxoadipate and quinolinic acid, which in turn cause toxicity in spinal motor neurons leading to spinal muscular atrophy-like disease
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