1,243 research outputs found

    Immediate replacement of fishing with dairying by the earliest farmers of the NE Atlantic archipelagos

    Get PDF
    The appearance of farming, from its inception in the Near East around 12 000 years ago, finally reached the northwestern extremes of Europe by the fourth millennium BC or shortly thereafter. Various models have been invoked to explain the Neolithization of northern Europe; however, resolving these different scenarios has proved problematic due to poor faunal preservation and the lack of specificity achievable for commonly applied proxies. Here, we present new multi-proxy evidence, which qualitatively and quantitatively maps subsistence change in the northeast Atlantic archipelagos from the Late Mesolithic into the Neolithic and beyond. A model involving significant retention of hunter–gatherer–fisher influences was tested against one of the dominant adoptions of farming using a novel suite of lipid biomarkers, including dihydroxy fatty acids, ω-(o-alkylphenyl)alkanoic acids and stable carbon isotope signatures of individual fatty acids preserved in cooking vessels. These new findings, together with archaeozoological and human skeletal collagen bulk stable carbon isotope proxies, unequivocally confirm rejection of marine resources by early farmers coinciding with the adoption of intensive dairy farming. This pattern of Neolithization contrasts markedly to that occurring contemporaneously in the Baltic, suggesting that geographically distinct ecological and cultural influences dictated the evolution of subsistence practices at this critical phase of European prehistory

    Blast Furnace Slag Usage and Guidance for Indiana

    Get PDF
    The project goal was to better understand the extent of air-cooled blast furnace slag (ACBFS) usage for completed INDOT projects, factors that can influence slag leaching, review remediation strategies, and identify applications where future usage restrictions or sitting criteria are needed. A literature review of government documents, peer-review, and trade industry literature was conducted. The project team also conducted a site visit to an ACBFS storage facility and steel mill that generated the ACBFS and reviewed handling and testing procedures. The project team also contacted other state transportation agencies (IL, MD, MI, NY, OH) to determine the degree they incorporated ACBFS into their projects and if product performance tests were required. Results show that changes to Indiana test methods and acceptance criteria are warranted. Indiana Test Method 212 should be revised to extend the test duration, pH acceptance criterion, and add additional material acceptance criteria. Unbound ACBFS should be avoided for construction applications (1) where ground water could contact the material, (2) near environmentally sensitive and populated areas, (3) where a drainage system is not present. Additional work to improve the ability of INDOT to detect ACBFS that would cause short- or long-term chemical leaching problems could include (1) evaluating and optimizing stockpile sampling practices for representative sampling, (2) modifying ITM 212 to better predict worst-case leaching conditions and leachate quality, (3) conduct a head-to-head comparison of bench-scale and field-scale leaching results

    Short-term Organic Carbon Release and Chlorine Disinfectant Decay for Cross-linked Polyethylene (PEX) Plumbing Pipes

    Get PDF
    The use of cross-linked polyethylene (PEX) plumbing pipes has grown in popularity for residential applications. However, PEX pipes can leach organic materials into water that can enable biofilm growth, cause off-tastes and -odors, and may react with disinfectants to form disinfection by-products (DBP). Varied manufacturing processes that are applied to create PEX pipes add to the complexity of understanding organic materials released. In this study, organic carbon release from three PEX pipe brands was monitored for up to five days using a series of stagnation periods. Seven stagnation periods of 1, 2, 4, 8, 24, 72, and 120 hours were conducted at 50 degrees Celsius with varying initial chlorine concentrations for a type A (PEX-a), type B (PEX-b), and type C (PEX-c) brand. Pipes were exposed to chlorinated tap water synthesized in the lab. Water exposed to these pipes was analyzed to determine total organic carbon (TOC), assimilable organic carbon (AOC), total chlorine, and free chlorine concentrations. Results show that all pipe brands had different chlorine decay rates and TOC concentrations. Chlorine residual decayed the slowest and fastest for PEX-A pipes and PEX-C pipes, respectively. Chlorine completely decayed in most pipes by 24 hours when the initial chlorine concentration was 2.0 mg/L. PEX-B leached the most amount of contaminants, with a TOC concentration that far exceeded 2.0 mg/L within 24 hours. AOC concentrations tended to increase over time for all pipes. Future work should include additional brands, aged PEX pipes, different flow conditions, temperatures, and longer stagnation periods

    Indoor Premise Plumbing: The Relationship Between Water Stagnation, Chlorine Decay, and Total Organic Carbon Levels

    Get PDF
    Drinking water safety is critical to the health of populations worldwide, and modern plumbing infrastructure can influence drinking water chemical characteristics. Inside residential and commercial buildings however, water use and contact with different plumbing components can vary. For example, water can endure lengthy stagnation periods and residual disinfectant agents like chlorine can decay, leaving the water vulnerable to microbial growth. Plastic cross-linked polyethylene (PEX) pipes have become popular and have shown to influence water quality. While several studies have been carried out on chemical leaching from PEX piping, none were found that examined the role of pipe diameter in relation to chlorine disinfectant decay. The study goal was to better understand chlorine decay in PEX piping associated with stagnation and pipe diameter. Different diameters (3/4”, ½”) of the same brand of PEX pipe were first obtained and cleaned. PEX pipe were filled with a laboratory prepared synthetic water with about 2 mg/L as Cl2 at pH 7.3 and stagnated up to 3 days at 50°C temperature. Chlorine disinfectant level, pH, and total organic carbon concentration were characterized periodically. Results will be compared against water samples that were not exposed to PEX pipe for the same time period

    Risk of End-stage Renal Disease Associated with Alcohol Consumption

    Get PDF
    Alcohol consumption has been linked to kidney disorders in selected patient groups, but whether it contributes to the burden of end-stage renal disease (ESRD) in the general population is unknown. The authors conducted population-based case-control study to asess the realation between alcohol consumption and risk of ESRD. The study took place in Maryland, Virginia, West Virginia, and Washington, DC, in 1991. Participants were 716 patients who had started treatment for ESRD and 361 control subjects of similar age (20-64 years) selected by random digit dialing. The main risk factor of interest was self-reported consumption of alcoholic beverages (frequency of drinking days and number of drinks consumed per drinking day). In univariate analysis, consumption of alcohol exhibited a J-shaped association with risk of ESRD. The J shape disappeared after exclusion of persons who had ever consumed home-distilled whiskey ("moonshine”) and adjustment for age, race, sex, income, history of hypertension, history of diabetes mellitus, use of acetaminophen, use of opiates, and cigarette smoking; however, the odds ratio for ESRD remained significantly increased (odds ratio = 4.0; 95% confidence interval: 1.2, 13.0) among persons who consumed an average of >2 alcoholic drinks per day. The corresponding population attributable risk was 9 percent. Thus, consumption of more than two alcoholic drinks per day, on average, was associated with an increased risk of kidney failure In the general population. A lower intake of alcohol did not appear to be harmful. Because these results are based on self-reports in a case-control study, they should be seen as preliminary. Am J Epidemiol 1999; 150:1275-8

    Lower Sodium Intake and Risk of Headaches: Results From the Trial of Nonpharmacologic Interventions in the Elderly.

    Get PDF
    ObjectivesTo determine the effect of sodium (Na) reduction on occurrence of headaches.MethodsIn the Trial of Nonpharmacologic Interventions in the Elderly, 975 men and woman (aged 60-80 years) with hypertension were randomized to a Na-reduction intervention or control group and were followed for up to 36 months. The study was conducted between 1992 and 1995 at 4 clinical centers (Johns Hopkins University, Wake Forest University School of Medicine, Robert Wood Johnson Medical School, and the University of Tennessee).ResultsMean difference in Na excretion between the Na-reduction intervention and control group was significant at each follow-up visit (P < .001) with an average difference of 38.8 millimoles per 24 hours. The occurrence of headaches was significantly lower in the Na-reduction intervention group (10.5%) compared with control (14.3%) with a hazard ratio of 0.59 (95% confidence interval = 0.40, 0.88; P = .009). The risk of headaches was significantly associated with average level of Na excretion during follow-up, independent of most recent blood pressure. The relationship appeared to be nonlinear with a spline relationship and a knot at 150 millimoles per 24 hours.ConclusionsReduced sodium intake, currently recommended for blood pressure control, may also reduce the occurrence of headaches in older persons with hypertension

    Navigating the Academic Job Search for Environmental Engineers: Guidance for Job Seekers and Mentors

    Get PDF
    Students and postdoctoral associates interested in tenure-track environmental engineering positions have limited resources to aid them. The Student Services Committee (SSC) of the Association of Environmental Engineering and Science Professors (AEESP) organized a workshop to fill some of the need. Newly hired faculty and experienced search committee and department chairs shared information on how to create competitive applications. Students and postdoctoral associates were also provided with individualized feedback on their faculty application packages. Survey data were collected for all participants, and these data are presented in this paper along with tips shared during the workshop and information collected from the literature. The objective of this paper is to share that information (1) to inform applicants (students and postdoctoral associates) about the academic job search process, and (2) to inform mentors about how to mentor applicants. Survey responses revealed that participants felt they learned valuable information about the job search process. They found the personalized feedback on application packages to be the most helpful activity; other mentors are encouraged to provide similar personalized feedback. A wiki website component included in the workshop was effective at engaging the participants and helped broaden the impact beyond the workshop attendees. Key lessons learned by comparing workshop results with literature were the importance of fit, the unique diversity of environmental engineering, mentoring and networking, Ph.D. planning sessions, being informed, and becoming a more skilled candidate. The recommendations presented in this paper can be used by students, postdoctoral associates, and their mentors to facilitate the candidate’s path toward academia
    corecore