1,203 research outputs found

    Functional diversity of marine ecosystems after the Late Permian mass extinction event

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    Article can be accessed from http://www.nature.com/ngeo/journal/v7/n3/full/ngeo2079.htmlThe Late Permian mass extinction event was the most severe such crisis of the past 500 million years and occurred during an episode of global warming. It is assumed to have had significant ecological impact, but its effects on marine ecosystem functioning are unknown and the patterns of marine recovery are debated. We analysed the fossil occurrences of all known Permian-Triassic benthic marine genera and assigned each to a functional group based on their inferred life habit. We show that despite the selective extinction of 62-74% of marine genera there was no significant loss of functional diversity at the global scale, and only one novel mode of life originated in the extinction aftermath. Early Triassic marine ecosystems were not as ecologically depauperate as widely assumed, which explains the absence of a Cambrian-style Triassic radiation in higher taxa. Functional diversity was, however, significantly reduced in particular regions and habitats, such as tropical reefs, and at these scales recovery varied spatially and temporally, probably driven by migration of surviving groups. Marine ecosystems did not return to their pre-extinction state, however, and radiation of previously subordinate groups such as motile, epifaunal grazers led to greater functional evenness by the Middle Triassic

    Ethanol Distribution, Dispensing, and Use: Analysis of a Portion of the Biomass-to-Biofuels Supply Chain Using System Dynamics

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    The Energy Independence and Security Act of 2007 targets use of 36 billion gallons of biofuels per year by 2022. Achieving this may require substantial changes to current transportation fuel systems for distribution, dispensing, and use in vehicles. The U.S. Department of Energy and the National Renewable Energy Laboratory designed a system dynamics approach to help focus government action by determining what supply chain changes would have the greatest potential to accelerate biofuels deployment. The National Renewable Energy Laboratory developed the Biomass Scenario Model, a system dynamics model which represents the primary system effects and dependencies in the biomass-to-biofuels supply chain. The model provides a framework for developing scenarios and conducting biofuels policy analysis. This paper focuses on the downstream portion of the supply chain–represented in the distribution logistics, dispensing station, and fuel utilization, and vehicle modules of the Biomass Scenario Model. This model initially focused on ethanol, but has since been expanded to include other biofuels. Some portions of this system are represented dynamically with major interactions and feedbacks, especially those related to a dispensing station owner’s decision whether to offer ethanol fuel and a consumer’s choice whether to purchase that fuel. Other portions of the system are modeled with little or no dynamics; the vehicle choices of consumers are represented as discrete scenarios. This paper explores conditions needed to sustain an ethanol fuel market and identifies implications of these findings for program and policy goals. A large, economically sustainable ethanol fuel market (or other biofuel market) requires low end-user fuel price relative to gasoline and sufficient producer payment, which are difficult to achieve simultaneously. Other requirements (different for ethanol vs. other biofuel markets) include the need for infrastructure for distribution and dispensing and widespread use of high ethanol blends in flexible-fuel vehicles

    Higher media multi-tasking activity is associated with smaller gray-matter density in the anterior cingulate cortex

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    Media multitasking, or the concurrent consumption of multiple media forms, is increasingly prevalent in today’s society and has been associated with negative psychosocial and cognitive impacts. Individuals who engage in heavier media-multitasking are found to perform worse on cognitive control tasks and exhibit more socio-emotional difficulties. However, the neural processes associated with media multi-tasking remain unexplored. The present study investigated relationships between media multitasking activity and brain structure. Research has demonstrated that brain structure can be altered upon prolonged exposure to novel environments and experience. Thus, we expected differential engagements in media multitasking to correlate with brain structure variability. This was confirmed via Voxel-Based Morphometry (VBM) analyses: Individuals with higher Media Multitasking Index (MMI) scores had smaller gray matter density in the anterior cingulate cortex (ACC). Functional connectivity between this ACC region and the precuneus was negatively associated with MMI. Our findings suggest a possible structural correlate for the observed decreased cognitive control performance and socio-emotional regulation in heavy media-multitaskers. While the cross-sectional nature of our study does not allow us to specify the direction of causality, our results brought to light novel associations between individual media multitasking behaviors and ACC structure differences

    The hand of Homo naledi

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    A nearly complete right hand of an adult hominin was recovered from the Rising Star cave system, South Africa. Based on associated hominin material, the bones of this hand are attributed to Homo naledi. This hand reveals a long, robust thumb and derived wrist morphology that is shared with Neandertals and modern humans, and considered adaptive for intensified manual manipulation. However, the finger bones are longer and more curved than in most australopiths, indicating frequent use of the hand during life for strong grasping during locomotor climbing and suspension. These markedly curved digits in combination with an otherwise human-like wrist and palm indicate a significant degree of climbing, despite the derived nature of many aspects of the hand and other regions of the postcranial skeleton in H. naledi

    Processing of inconsistent emotional information: an fMRI study

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    Previous studies investigating the anterior cingulate cortex (ACC) have relied on a number of tasks which involved cognitive control and attentional demands. In this fMRI study, we tested the model that ACC functions as an attentional network in the processing of language. We employed a paradigm that requires the processing of concurrent linguistic information predicting that the cognitive costs imposed by competing trials would engender the activation of ACC. Subjects were confronted with sentences where the semantic content conflicted with the prosodic intonation (CONF condition) randomly interspaced with sentences which conveyed coherent discourse components (NOCONF condition). We observed the activation of the rostral ACC and the middle frontal gyrus when the NOCONF condition was subtracted from the CONF condition. Our findings provide evidence for the involvement of the rostral ACC in the processing of complex competing linguistic stimuli, supporting theories that claim its relevance as a part of the cortical attentional circuit. The processing of emotional prosody involved a bilateral network encompassing the superior and medial temporal cortices. This evidence confirms previous research investigating the neuronal network that supports the processing of emotional information

    Factors associated with herbal use among urban multiethnic primary care patients: a cross-sectional survey

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    BACKGROUND: The use of herbal supplements in the United States has become increasingly popular. The prevalence of herbal use among primary care patients varies in previous studies; the pattern of herbal use among urban racially/ethnically diverse primary care patients has not been widely studied. The primary objectives of this study were to describe the use of herbs by ethnically diverse primary care patients in a large metropolitan area and to examine factors associated with such use. The secondary objective was to investigate perceptions about and patterns of herbal use. METHODS: Data for a cross-sectional survey were collected at primary care practices affiliated with the Southern Primary-care Urban Research Network (SPUR-Net) in Houston, Texas, from September 2002 to March 2003. To participate in the study, patients had to be at least 18 years of age and visiting one of the SPUR-Net clinics for routine, nonacute care. Survey questions were available in both English and Spanish. RESULTS: A total of 322 patients who had complete information on race/ethnicity were included in the analysis. Overall, 36% of the surveyed patients (n = 322) indicated use of herbs, with wide variability among ethnic groups: 50% of Hispanics, 50% of Asians, 41% of Whites, and 22% of African-Americans. Significant factors associated with an individual's herbal use were ethnicity other than African-American, having an immigrant family history, and reporting herbal use by other family members. About 40% of survey respondents believed that taking prescription medications and herbal medicines together was more effective than taking either alone. One-third of herbal users reported using herbs on a daily basis. More Whites (67%) disclosed their herbal use to their health-care providers than did African-Americans (45%), Hispanics (31%), or Asians (31%). CONCLUSIONS: Racial/ethnic differences in herbal use were apparent among this sample of urban multiethnic adult primary care patients. Associated factors of herbal use were non-African-American ethnicity, immigrant family history, and herbal use among family members. Whereas Hispanics and Asians reported the highest rates of herbal use, they were the least likely to disclose their use to health-care professionals. These findings are important for ensuring medication safety in primary care practices

    Screening and brief interventions for hazardous and harmful alcohol use in primary care: a cluster randomised controlled trial protocol

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    A large number of randomised controlled trials in health settings have consistently reported positive effects of brief intervention in terms of reductions in alcohol use. However,although alcohol misuse is common amongst offenders, there is limited evidence of alcohol brief interventions in the criminal justice field. This factorial pragmatic cluster randomised controlledtrial with Offender Managers (OMs) as the unit of randomisation will evaluate the effectiveness and cost-effectiveness of different models of screening to identify hazardous and harmful drinkers in probation and different intensities of brief intervention to reduce excessive drinking in probation clients. Ninety-six OMs from 9 probation areas across 3 English regions (the NorthEast Region (n = 4) and London and the South East Regions (n = 5)) will be recruited. OMs will berandomly allocated to one of three intervention conditions: a client information leaflet control condition (n = 32 OMs); 5-minute simple structured advice (n = 32 OMs) and 20-minute brieflifestyle counselling delivered by an Alcohol Health Worker (n = 32 OMs). Randomisation will be stratified by probation area. To test the relative effectiveness of different screening methods all OMs will be randomised to either the Modified Single Item Screening Questionnaire (M-SASQ) orthe Fast Alcohol Screening Test (FAST). There will be a minimum of 480 clients recruited into the trial. There will be an intention to treat analysis of study outcomes at 6 and 12 months postintervention. Analysis will include client measures (screening result, weekly alcohol consumption,alcohol-related problems, re-offending, public service use and quality of life) and implementation measures from OMs (the extent of screening and brief intervention beyond the minimum recruitment threshold will provide data on acceptability and feasibility of different models of brief intervention). We will also examine the practitioner and organisational factors associated with successful implementation.The trial will evaluate the impact of screening and brief alcohol intervention in routine probation work and therefore its findings will be highly relevant to probation teams and thus the criminal justice system in the UK

    Dio-sensimedia: a novel culture medium for rapid detection of extended spectrum β-lactamases

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    BACKGROUND: Resistance to contemporary broad-spectrum β-lactams, mediated by extended-spectrum β-lactamases (ESBL), is an increasing problem worldwide. Many of the emerging antimicrobial resistance problems of this decade have been characterized by difficulty in the recognition of resistance in the laboratory, particularly by rapid susceptibility test methods. The plasmid-encoded ESBL represent such a resistance phenomenon that is difficult to recognize. We compared Dio-Sensimedia-ES (DSM-ES; Diomed, Istanbul, Turkey) and Mueller-Hinton (MH) agar in the double-disk synergy test (DDST) as a novel rapid system for detecting ESBL directly from bacterial culture. METHODS: Sixty ESBL-producing Klebsiella pneumoniae isolates cultured from blood (30), endotracheal aspirates (20), urine (5) and pus (5), as well as 40 Escherichia coli isolates cultured from endotracheal aspirates (15), urine (10), blood (8) and pus (7) were studied. Isolates positive for ESBL by the combined disk tests were tested with the DDST using MH and DSM-ES agar to detect ESBL-mediated resistance in K. pneumoniae and E. coli. DSM-ES agar was also used to determine the susceptibility of Enterobacteriaceae and staphylococci. RESULTS: Among 60 ESBL-producing K. pneumoniae isolates, 59 (98.3%) were identified as ESBL-positive by the DDST using MH, and 58 (96.6%), using DSM-ES agar. Of 40 ESBL-producing E. coli isolates, 38 (95%) were ESBL-positive by the DDST on MH agar, and 37 (92.5%), on DSM-ES agar. The average incubation period required for ESBL detection by the DDST on DSM-ES agar was 4 hours. CONCLUSIONS: Since the DDST results were available within 4 hours when DSM-ES agar was used, the use of this media may significantly lower the length of hospital stay, the total cost for patient care and even the mortality rate by fascilitating early treatment against ESBL-producing organisms
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