204 research outputs found

    Report on the 2013 Rapid Assessment Survey of Marine Species at New England Bays and Harbors

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    Introduced species (i.e., non-native species that have become established in a new location) have increasingly been recognized as a concern as they have become more prevalent in marine and terrestrial environments (Mooney and Cleland 2001; Simberloff et al. 2005). The ability of introduced species to alter population, community, and ecosystem structure and function, as well as cause significant economic damage is well documented (Carlton 1989, 1996b, 2000; Cohen and Carlton 1995; Cohen et al. 1995; Elton 1958; Meinesz et al. 1993; Occhipinti-Ambrogi and Sheppard 2007; Pimentel et al. 2005; Thresher 2000). The annual economic costs incurred from managing the approximately 50,000 introduced species in the United States alone are estimated to be over $120 billion (Pimentel et al. 2005). Having a monitoring network in place to track new introductions and distributional changes of introduced species is critical for effective management, as these efforts may be more successful when species are detected before they have the chance to become established. A rapid assessment survey is one such method for early detection of introduced species. With rapid assessment surveys, a team of taxonomic experts record and monitor marine species–providing a baseline inventory of native, introduced, and cryptogenic (i.e., unknown origin) species (as defined by Carlton 1996a)–and document range expansions of previously identified species. Since 2000, five rapid assessment surveys have been conducted in New England. These surveys focus on recording species at marinas, which often are in close proximity to transportation vectors (i.e., recreational boats). Species are collected from floating docks and piers because these structures are accessible regardless of the tidal cycle. Another reason for sampling floating docks and other floating structures is that marine introduced species are often found to be more prevalent on artificial surfaces than natural surfaces (Glasby and Connell 2001; Paulay et al. 2002). The primary objectives of these surveys are to: (1) identify native, introduced, and cryptogenic marine species, (2) expand on data collected in past surveys, (3) assess the introduction status and range extensions of documented introduced species, and (4) detect new introductions. This report presents the introduced, cryptogenic, and native species recorded during the 2013 survey

    Editorial Perspective: Speaking up for developmental language disorder - the top 10 priorities for research

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    Developmental language disorder (DLD) is one of the most common neurodevelopmental conditions, yet is chronically underserved, with far fewer children receiving clinical services than expected from prevalence estimates, and very little research attention relative to other neurodevelopmental conditions of similar prevalence and severity. This editorial describes a research priority-setting exercise undertaken by the Royal College of Speech and Language Therapists, which aims to redress this imbalance. From consultations with researchers, practitioners and individuals with lived experience, 10 research priorities emerge. Our goal is to share these priorities with the wider research community, to raise awareness and encourage research collaboration to improve outcomes for young people with DLD

    Report on the 2013: Rapid assessment survey of marine species at New England Bays and Harbors

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    Introduced species (i.e., non-native species that have become established in\ud a new location) have increasingly been recognized as a concern as they have\ud become more prevalent in marine and terrestrial environments (Mooney and\ud Cleland 2001; Simberloff et al. 2005). The ability of introduced species to alter\ud population, community, and ecosystem structure and function, as well as\ud cause significant economic damage is well documented (Carlton 1989, 1996b,\ud 2000; Cohen and Carlton 1995; Cohen et al. 1995; Elton 1958; Meinesz et al.\ud 1993; Occhipinti-Ambrogi and Sheppard 2007; Pimentel et al. 2005; Thresher\ud 2000). The annual economic costs incurred from managing the approximately\ud 50,000 introduced species in the United States alone are estimated to be over\ud $120 billion (Pimentel et al. 2005).\ud Having a monitoring network in place to track new introductions and\ud distributional changes of introduced species is critical for effective\ud management, as these efforts may be more successful when species are\ud detected before they have the chance to become established. A rapid\ud assessment survey is one such method for early detection of introduced\ud species. With rapid assessment surveys, a team of taxonomic experts\ud record and monitor marine species–providing a baseline inventory of\ud native, introduced, and cryptogenic (i.e., unknown origin) species (as\ud defined by Carlton 1996a)–and document range expansions of previously\ud identified species.\ud Since 2000, five rapid assessment surveys have been conducted in New\ud England. These surveys focus on recording species at marinas, which often\ud are in close proximity to transportation vectors (i.e., recreational boats).\ud Species are collected from floating docks and piers because these structures\ud are accessible regardless of the tidal cycle. Another reason for sampling floating\ud docks and other floating structures is that marine introduced species are often\ud found to be more prevalent on artificial surfaces than natural surfaces (Glasby\ud and Connell 2001; Paulay et al. 2002). The primary objectives of these surveys\ud are to: (1) identify native, introduced, and cryptogenic marine species,\ud (2) expand on data collected in past surveys, (3) assess the introduction status\ud and range extensions of documented introduced species, and (4) detect new\ud introductions. This report presents the introduced, cryptogenic, and native\ud species recorded during the 2013 survey.CZM through NOAA NA13NOS4190040MIT Sea Grant through NOAA NA10OAR4170086

    Community Code Verification Exercise for Simulating Sequences of Earthquakes and Aseismic Slip (SEAS)

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    Numerical simulations of sequences of earthquakes and aseismic slip (SEAS) have made great progress over past decades to address important questions in earthquake physics. However, significant challenges in SEAS modeling remain in resolving multiscale interactions between earthquake nucleation, dynamic rupture, and aseismic slip, and understanding physical factors controlling observables such as seismicity and ground deformation. The increasing complexity of SEAS modeling calls for extensive efforts to verify codes and advance these simulations with rigor, reproducibility, and broadened impact. In 2018, we initiated a community code‐verification exercise for SEAS simulations, supported by the Southern California Earthquake Center. Here, we report the findings from our first two benchmark problems (BP1 and BP2), designed to verify different computational methods in solving a mathematically well‐defined, basic faulting problem. We consider a 2D antiplane problem, with a 1D planar vertical strike‐slip fault obeying rate‐and‐state friction, embedded in a 2D homogeneous, linear elastic half‐space. Sequences of quasi‐dynamic earthquakes with periodic occurrences (BP1) or bimodal sizes (BP2) and their interactions with aseismic slip are simulated. The comparison of results from 11 groups using different numerical methods show excellent agreements in long‐term and coseismic fault behavior. In BP1, we found that truncated domain boundaries influence interseismic stressing, earthquake recurrence, and coseismic rupture, and that model agreement is only achieved with sufficiently large domain sizes. In BP2, we found that complexity of fault behavior depends on how well physical length scales related to spontaneous nucleation and rupture propagation are resolved. Poor numerical resolution can result in artificial complexity, impacting simulation results that are of potential interest for characterizing seismic hazard such as earthquake size distributions, moment release, and recurrence times. These results inform the development of more advanced SEAS models, contributing to our further understanding of earthquake system dynamics

    New cytochrome P450 1B1, 1C2 and 1D1 genes in the killifish Fundulus heteroclitus : Basal expression and response of five killifish CYP1s to the AHR agonist PCB126

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    Author Posting. © Elsevier B.V., 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Aquatic Toxicology 93 (2009): 234-243, doi:10.1016/j.aquatox.2009.05.008.Knowledge of the complement of cytochrome P450 (CYP) genes is essential to understanding detoxification and bioactivation mechanisms for organic contaminants.We cloned three new CYP1 genes, CYP1B1, CYP1C2 and CYP1D1, from the killifish Fundulus heteroclitus, an important model in environmental toxicology. Expression of the new CYP1s along with previously known CYP1A and CYP1C1 was measured by qPCR in eight different organs. Organ distribution was similar for the two CYP1Cs, but otherwise patterns and extent of expression differed among the genes. The AHR agonist 3,3_,4,4_,5-pentachlorobiphenyl (PCB126) (31 pmol/g fish) induced expression of CYP1A and CYP1B1 in all organs examined, while CYP1C1 was induced in all organs except testis. The largest changes in response to PCB126 were induction of CYP1A in testis (~700-fold) and induction of CYP1C1 in liver (~500-fold). CYP1B1 in liver and gut, CYP1A in brain and CYP1C1 in gill also were induced strongly by PCB126 (>100-fold). CYP1C1 expression levels were higher than CYP1C2 in almost all tissues and CYP1C2 was much less responsive to PCB126. In contrast to the other genes, CYP1D1 was not induced by PCB126 in any of the organs. The organ-specific response of CYP1s to PCB126 implies differential involvement in effects of halogenated aromatic hydrocarbons in different organs. The suite of inducible CYP1s could enhance the use of F. heteroclitus in assessing aquatic contamination by AHR agonists. Determining basal and induced levels of protein and the substrate specificity for all five CYP1s will be necessary to better understand their roles in chemical effects and physiology.This study was supported in part by NIH grants JJS (the Superfund Basic Research Program 5P42ES007381 and R01ES015912) and MJJ (K99ES017044-01)

    Light Curves and Colors of the Ejecta from Dimorphos after the DART Impact

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    On 26 September 2022 the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, a satellite of the asteroid 65803 Didymos. Because it is a binary system, it is possible to determine how much the orbit of the satellite changed, as part of a test of what is necessary to deflect an asteroid that might threaten Earth with an impact. In nominal cases, pre-impact predictions of the orbital period reduction ranged from ~8.8 - 17.2 minutes. Here we report optical observations of Dimorphos before, during and after the impact, from a network of citizen science telescopes across the world. We find a maximum brightening of 2.29 ±\pm 0.14 mag upon impact. Didymos fades back to its pre-impact brightness over the course of 23.7 ±\pm 0.7 days. We estimate lower limits on the mass contained in the ejecta, which was 0.3 - 0.5% Dimorphos' mass depending on the dust size. We also observe a reddening of the ejecta upon impact.Comment: Accepted by Natur

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be ∌24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with ÎŽ<+34.5∘\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r∌27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

    Inhibition of Bax protects neuronal cells from oligomeric AÎČ neurotoxicity

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    Although oligomeric ÎČ-amyloid (AÎČ) has been suggested to have an important role in Alzheimer disease (AD), the mechanism(s) of how AÎČ induces neuronal cell death has not been fully identified. The balance of pro- and anti-apoptotic Bcl-2 family proteins (e.g., Bcl-2 and Bcl-w versus Bad, Bim and Bax) has been known to have a role in neuronal cell death and, importantly, expression levels of these proteins are reportedly altered in the vulnerable neurons in AD. However, the roles of apoptotic proteins in oligomeric AÎČ-induced cell death remain unclear in vivo or in more physiologically relevant models. In addition, no study to date has examined whether Bax is required for the toxicity of oligomeric AÎČ. Here, we found that treatment with oligomeric AÎČ increased Bim levels but decreased Bcl-2 levels, leading to the activation of Bax and neuronal cell death in hippocampal slice culture and in vivo. Furthermore, the inhibition of Bax activity either by Bax-inhibiting peptide or bax gene knockout significantly prevented oligomeric AÎČ-induced neuronal cell death. These findings are first to demonstrate that Bax has an essential role in oligomeric AÎČ-induced neuronal cell death, and that the targeting of Bax may be a therapeutic approach for AD

    Exome sequencing identifies novel AD-associated genes

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    The genetic component of Alzheimer’s disease (AD) has been mainly assessed using Genome Wide Association Studies (GWAS), which do not capture the risk contributed by rare variants. Here, we compared the gene-based burden of rare damaging variants in exome sequencing data from 32,558 individuals —16,036 AD cases and 16,522 controls— in a two-stage analysis. Next to known genes TREM2, SORL1 and ABCA7, we observed a significant association of rare, predicted damaging variants in ATP8B4 and ABCA1 with AD risk, and a suggestive signal in ADAM10. Next to these genes, the rare variant burden in RIN3, CLU, ZCWPW1 and ACE highlighted these genes as potential driver genes in AD-GWAS loci. Rare damaging variants in these genes, and in particular loss-of-function variants, have a large effect on AD-risk, and they are enriched in early onset AD cases. The newly identified AD-associated genes provide additional evidence for a major role for APP-processing, AÎČ-aggregation, lipid metabolism and microglial function in AD
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