66 research outputs found

    Using S Isotopes to Identify the Source of Gypsum in Mammoth Cave

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    Many of the dry passages of the cave are lined with gypsum (CaSO4�2H2O) crystals, an evaporite mineral. However, the source of the sulfur in these gypsum deposits is poorly constrained with possible sources including pyrite, sedimentary gypsum/anhydrite, and carbonate associated sulfate (“CAS”, SO42- substituted for CO3 2- in the calcite crystal lattice). The two most abundant forms of sulfur in the bedrock above and around Mammoth Cave are pyrite (FeSs) and CAS. These phases commonly have very different isotopic signatures (δ34S)* and the δ34S values of these phases can be compared to the δ34S of the gypsum to aid in identifying the source of the sulfur. Isolation of sulfur from pyrite and CAS is currently ongoing. Results from 110 gypsum crystals, 4 rocks in strata from within the caves, and 15 rocks from strata overlying the caves reveal some distinct patterns. 1) Gypsum crystals show relatively small scatter (~5‰) for samples from a single location (e.g. a 30 m2 room). 2) A significant correlation between δ34Sgypsum and elevation suggests a variable δ34Ssource over vertical distances of a few meters. 3) Microsampling of sulfur along the growth axes of single gypsum crystals shows a constant δ34S values suggesting no change in δ34S of the S source during its growth. Because the growth period of these crystals may be on the order of thousands of years, these results suggest a constant sulfate for long intervals. The relationship to δ34S of samples in a given room and elevation suggests that the source of gypsum sulfur is local, arising from lateral, rather than vertical, fluid fl ow, an important insight into the transport pathways of water in a karstic system. Sampling of pyrite and CAS is currently ongoing. *δ34S = [(34S/32Ssample)/(34S/32Sstandard)-1(x)1,000‰ where 34S and 32S are the molar ratios of each S isotope given in “per mil” (‰), equivalent to parts per thousand

    Nova spoznanja o nastanku piroduktov Galapaškega otočja, Ekvador

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    There has been little research on the genesis and development of pyroducts (or lava tubes) originating from Gala´pagos volcanoes. Pyroducts are responsible for the lateral, post-eruptive transport of lava because they are highly effective as thermal insulators. After eruptions terminate, these conduits often become accessible as caves. In March 2014 the 16th International Symposium on Vulcanospeleology brought a large group of vulcanospeleological specialists to the Islands. During the meeting a number of pyroducts were visited and studied in context on the island of Santa Cruz and around Isabella’s Sierra Negra volcano in the western, most active, part of the Gala´pagos. The longest of the caves, Cueva del Cascajo, about 3 km in length, was partly surveyed and nine other caves were visited. Structural features such as thickness of roof, evidence of downcutting, presence of oxbows, secondary ceilings, lavafalls, collapses and pukas were particularly studied for evidence they reveal about developmental stages of pyroducts. The resulting data show that the pyroducts were formed by "inflation" with the primary roof consisting of uninterrupted paŻhoehoe sheets. No pyroducts were identified that developed by the crusting-over of channels. The studies strongly confirm inferences drawn from other hot-spot related islands, such as Hawai’i.Raziskav o nastanku in razvoju piroduktov ali lavinih cevi na galapaških vulkanih je malo. Pirodukti so pomembni za bočni transport lave po izbruhu in so toplotni ščit med tokom lave in zunanjim ozračjem. Po končanem izbruhu ti kanali ostanejo dostopni kot lavine cevi. Marca 2014 je na Galapaškem otočju potekal 16. mednarodni simpozij o vulkanospeleologiji. V okviru tega smo obiskali in proučevali številne pirodukte na otoku Santa Cruz in v okolici vulkana Isabella's Sierra Negra na zahodnem, najaktivnejšem delu Galapaškega otočja. Delno smo izmerili najdaljšo, 3 km dolgo jamo Cueva del Cascajo in obiskali še devet drugih jam. Pri tem smo bili pozorni na strukturne elemente, ki kažejo na razvojne faze piroduktov, kot so debelina stropa, vrezovanje, prisotnost obvodnih rovov (oxbow), ostankov lavinih slapov, sekundarnih stropov, odprtin na površje (puka) in vdorov. Podatki in opažanja kažejo, da so jame nastale z zaporednim napredovanjem in napihovanjem, na kar kaže tudi primarni strop iz neprekinjenih plasti pahoehoe lave.. Nobeden od piroduktov ni nastal zaradi strjevanja lave nad tokom. Podobne ugotovitve veljajo tudi jame na vulkanih drugih vročih točk, kot na primer na havajskih vulkanih

    Development and interval testing of a naturalistic driving methodology to evaluate driving behavior in clinical research [version 2; referees: 2 approved]

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    Background: The number of older adults in the United States will double by 2056. Additionally, the number of licensed drivers will increase along with extended driving-life expectancy. Motor vehicle crashes are a leading cause of injury and death in older adults. Alzheimer’s disease (AD) also negatively impacts driving ability and increases crash risk. Conventional methods to evaluate driving ability are limited in predicting decline among older adults. Innovations in GPS hardware and software can monitor driving behavior in the actual environments people drive in. Commercial off-the-shelf (COTS) devices are affordable, easy to install and capture large volumes of data in real-time. However, adapting these methodologies for research can be challenging. This study sought to adapt a COTS device and determine an interval that produced accurate data on the actual route driven for use in future studies involving older adults with and without AD.  Methods: Three subjects drove a single course in different vehicles at different intervals (30, 60 and 120 seconds), at different times of day, morning (9:00-11:59AM), afternoon (2:00-5:00PM) and night (7:00-10pm). The nine datasets were examined to determine the optimal collection interval. Results: Compared to the 120-second and 60-second intervals, the 30-second interval was optimal in capturing the actual route driven along with the lowest number of incorrect paths and affordability weighing considerations for data storage and curation. Discussion: Use of COTS devices offers minimal installation efforts, unobtrusive monitoring and discreet data extraction.  However, these devices require strict protocols and controlled testing for adoption into research paradigms.  After reliability and validity testing, these devices may provide valuable insight into daily driving behaviors and intraindividual change over time for populations of older adults with and without AD.  Data can be aggregated over time to look at changes or adverse events and ascertain if decline in performance is occurring

    Polychaetous annelids from Hawaii

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    4 p. : ill. ; 24 cm.Includes bibliographical references (p. 4)

    High-yield atmospheric water capture via bioinspired material segregation

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    Atmospheric water harvesting is urgently needed given increasing global water scarcity. Current sorbent-based devices that cycle between water capture and release have low harvesting rates. We envision a radically different multi-material architecture with segregated and simultaneous capture and release. This way, proven fast-release mechanisms that approach theoretical limits can be incorporated; however, no capture mechanism exists to supply liquid adequately for release. Inspired by tree frogs and airplants, our capture approach transports water through a hydrogel membrane ``skin'' into a liquid desiccant. We report an extraordinarily high capture rate of 5.50 kgm2d1\text{kg}\,\text{m}^{-2}\,\text{d}^{-1} at a low humidity of 35%, limited by the convection of air to the device. At higher humidities, we demonstrate up to 16.9 kgm2d1\text{kg}\,\text{m}^{-2}\,\text{d}^{-1}, exceeding theoretical limits for release. Simulated performance of a hypothetical one-square-meter device shows that water could be supplied to two to three people in dry environments. This work is a significant step toward providing new resources to water-scarce regions.Comment: 22 pages, 23 figure

    Comparing ST-segment elevation myocardial infarction care between patients residing in central and remote locations: a retrospective case series.

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    People who experience an ST-elevation myocardial infarction (STEMI) due to an occluded coronary artery require prompt treatment. Treatments to open a blocked artery are called reperfusion therapies (RTs), and can include intravenous pharmacological thrombolysis (TL) or primary percutaneous coronary intervention (pPCI) in a cardiac catheterisation laboratory (cath lab). Optimal RT (ORT) with pPCI or TL reduces morbidity and mortality. In remote areas, a number of geographical and organisational barriers may influence access to ORT. These are not well understood, and the exact proportion of patients who receive ORT - and the relationship to time of day and remoteness from the cardiac cath lab - is unknown. The aim of this retrospective study was to compare the characteristics of ORT delivery in central and remote locations in the north of Scotland, and to identify potential barriers to optimal care with a view to service redesign. The study was set in the north of Scotland. All patients who attended hospital with a STEMI between March 2014 and April 2015 were identified from national coding data. A data collection form was developed by the research team in several iterative stages. Clinical details were collected retrospectively from patients' discharge letters. Data included treatment location, date of admission, distance of patient from the cath lab, route of access to health care, left ventricular function and RT received. Distance of patients from the cath lab was described as remote if they were more than ninety minutes of driving time from the cardiac cath lab, and described as central if they were ninety minutes or less of driving time from the regional centre. For patients who made contact in a pre-hospital setting, ORT was defined as pre-hospital TL (PHT) or pPCI. For patients who self-presented to the hospital first, ORT was defined as in-hospital TL or pPCI. Data were described as mean (standard deviation) as appropriate. Chi-squared and student's t-test were used as appropriate. Each case was reviewed to determine if ORT was received; if ORT was not received, the reasons for this were recorded to identify potentially modifiable barriers. Of the 627 acute myocardial infarction patients initially identified, 131 had a STEMI, and the others were non-STEMI. From this STEMI cohort, 82 (62%) patients were classed as central and 49 (38%) were remote. In terms of initial therapy, 26 (20%) received pPCI, 19 (15%) received PHTs, 52 (40%) received in-hospital TL, while 33 (25%) received no initial RT. ORT was received by 53 (65%) central and 20 (41%) remote patients; chi-squared = 7.05, degrees of freedom = 130, p < 0.01).Several recurring barriers were identified. This study has therefore demonstrated a significant health inequality between the treatment of STEMI in remote locations compared to central locations. Potential barriers identified include staffing availability and training, public awareness and inter-hospital communication. This suggests that there remain significant opportunities to improve STEMI care for people living in the north of Scotland

    Creating a driving profile for older adults using GPS devices and naturalistic driving methodology

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    Background/Objectives: Road tests and driving simulators are most commonly used in research studies and clinical evaluations of older drivers. Our objective was to describe the process and associated challenges in adapting an existing, commercial, off-the-shelf (COTS), in-vehicle device for naturalistic, longitudinal research to better understand daily driving behavior in older drivers. Design: The Azuga G2 Tracking DeviceTM was installed in each participant’s vehicle, and we collected data over 5 months (speed, latitude/longitude) every 30-seconds when the vehicle was driven.  Setting: The Knight Alzheimer’s Disease Research Center at Washington University School of Medicine. Participants: Five individuals enrolled in a larger, longitudinal study assessing preclinical Alzheimer disease and driving performance.  Participants were aged 65+ years and had normal cognition. Measurements:  Spatial components included Primary Location(s), Driving Areas, Mean Centers and Unique Destinations.  Temporal components included number of trips taken during different times of the day.  Behavioral components included number of hard braking, speeding and sudden acceleration events. Methods:  Individual 30-second observations, each comprising one breadcrumb, and trip-level data were collected and analyzed in R and ArcGIS.  Results: Primary locations were confirmed to be 100% accurate when compared to known addresses.  Based on the locations of the breadcrumbs, we were able to successfully identify frequently visited locations and general travel patterns.  Based on the reported time from the breadcrumbs, we could assess number of trips driven in daylight vs. night.  Data on additional events while driving allowed us to compute the number of adverse driving alerts over the course of the 5-month period. Conclusions: Compared to cameras and highly instrumented vehicle in other naturalistic studies, the compact COTS device was quickly installed and transmitted high volumes of data. Driving Profiles for older adults can be created and compared month-to-month or year-to-year, allowing researchers to identify changes in driving patterns that are unavailable in controlled conditions

    Key ethical challenges in the European Medical Information Framework

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    The European Medical Information Framework (EMIF) project, funded through the IMI programme (Innovative Medicines Initiative Joint Undertaking under Grant Agreement No. 115372), has designed and implemented a federated platform to connect health data from a variety of sources across Europe, to facilitate large scale clinical and life sciences research. It enables approved users to analyse securely multiple, diverse, data via a single portal, thereby mediating research opportunities across a large quantity of research data. EMIF developed a code of practice (ECoP) to ensure the privacy protection of data subjects, protect the interests of data sharing parties, comply with legislation and various organisational policies on data protection, uphold best practices in the protection of personal privacy and information governance, and eventually promote these best practices more widely. EMIF convened an Ethics Advisory Board (EAB), to provide feedback on its approach, platform, and the EcoP. The most important challenges the ECoP team faced were: how to define, control and monitor the purposes (kinds of research) for which federated health data are used; the kinds of organisation that should be permitted to conduct permitted research; and how to monitor this. This manuscript explores those issues, offering the combined insights of the EAB and EMIF core ECoP team. For some issues, a consensus on how to approach them is proposed. For other issues, a singular approach may be premature but the challenges are summarised to help the community to debate the topic further. Arguably, the issues and their analyses have application beyond EMIF, to many research infrastructures connected to health data sources

    Exploiting bacterial effector proteins to uncover evolutionarily conserved antiviral host machinery.

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    Arboviruses are a diverse group of insect-transmitted pathogens that pose global public health challenges. Identifying evolutionarily conserved host factors that combat arbovirus replication in disparate eukaryotic hosts is important as they may tip the balance between productive and abortive viral replication, and thus determine virus host range. Here, we exploit naturally abortive arbovirus infections that we identified in lepidopteran cells and use bacterial effector proteins to uncover host factors restricting arbovirus replication. Bacterial effectors are proteins secreted by pathogenic bacteria into eukaryotic hosts cells that can inhibit antimicrobial defenses. Since bacteria and viruses can encounter common host defenses, we hypothesized that some bacterial effectors may inhibit host factors that restrict arbovirus replication in lepidopteran cells. Thus, we used bacterial effectors as molecular tools to identify host factors that restrict four distinct arboviruses in lepidopteran cells. By screening 210 effectors encoded by seven different bacterial pathogens, we identify several effectors that individually rescue the replication of all four arboviruses. We show that these effectors encode diverse enzymatic activities that are required to break arbovirus restriction. We further characterize Shigella flexneri-encoded IpaH4 as an E3 ubiquitin ligase that directly ubiquitinates two evolutionarily conserved proteins, SHOC2 and PSMC1, promoting their degradation in insect and human cells. We show that depletion of either SHOC2 or PSMC1 in insect or human cells promotes arbovirus replication, indicating that these are ancient virus restriction factors conserved across invertebrate and vertebrate hosts. Collectively, our study reveals a novel pathogen-guided approach to identify conserved antimicrobial machinery, new effector functions, and conserved roles for SHOC2 and PSMC1 in virus restriction
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