199 research outputs found

    Magnitudes and sources of precipitation and dry deposition fluxes of indestrial and natural leads to the North Pacific at Enewetak

    Get PDF
    A total atmospheric Pb input flux of 7 ng Pb cm^−2 yr^−1 was measured in the North Pacific Easterlies at Enewetak. Parameters used to measure this flux were ratio of dry deposition flux to precipitation flux; Pb/^(210)Pb in precipitation and seawater; ^(210)Pb flux; washout factor; and Pb concentrations in air, rain, and dry deposition deposits. Relations among these parameters established at Enewetak were used to recompute and confirm previous estimates of lead fluxes to the oceans (ng Pb cm^−2 yr^−1) at the following locations: North Atlantic Westerlies, 170; North Pacific Westerlies, 50; and South Pacific Easterlies, 3. Prehistoric lead output fluxes to sediments (ng Pb cm^−2 yr^−1) at these locations have been previously measured and were 4 (Enewetak); 30 North Atlantic Westerlies; 3 North Pacific Westerlies; 4 South Pacific Easterlies. These data show that the rates of atmospheric inputs of lead to the oceans vary directly with variations in rates of upwind emissions of industrial lead from urban complexes on land. In the North Pacific and North Atlantic, present rates of atmospheric lead inputs are 10-fold greater than prehistoric outputs. In equatorial regions, present inputs and past outputs are more nearly equal. These observations disclose the effects of intense industrial atmospheric emissions of lead in the northern hemisphere westerlies which have overwhelmed prehistoric natural fluxes of lead to the oceans. The average concentration of lead in marine air at Enewetak is 170 pg m−3 and varies less than a factor of 2 from that mean. One to 15% of this lead comes from seaspray, while the remainder comes from sources on land. About 90% of the seaspray lead is industrial, while 80 to 99% of that originating from land sources is industrial. Concentrations of lead in rain at Enewetak range from 6 to 63 pg/g with a mean value of 28. The mean precipitation flux, corrected for recycled lead in sea salts, measured by four different methods, was 6 ng Pb cm^−2 yr^−1, while the net dry deposition flux measured on horizontal plastic plates was 0.6 ng Pb cm^−2 yr^−1. The total dry deposition flux measured was 6 ng cm^−2 yr^−1, but 90% of this lead came from recycled seaspray. Lead isotope tracers show that Japan is the major source of industrial lead at Enewetak during the dry season, while the United States is the major source during the wet season

    Abrogation of MAP4K4 protein function causes congenital anomalies in humans and zebrafish

    Get PDF
    We report 21 families displaying neurodevelopmental differences and multiple congenital anomalies while bearing a series of rare variants i

    Frequency and Circadian Timing of Eating May Influence Biomarkers of Inflammation and Insulin Resistance Associated with Breast Cancer Risk.

    Get PDF
    Emerging evidence suggests that there is interplay between the frequency and circadian timing of eating and metabolic health. We examined the associations of eating frequency and timing with metabolic and inflammatory biomarkers putatively associated with breast cancer risk in women participating in the National Health and Nutrition Examination 2009-2010 Survey. Eating frequency and timing variables were calculated from 24-hour food records and included (1) proportion of calories consumed in the evening (5 pm-midnight), (2) number of eating episodes per day, and (3) nighttime fasting duration. Linear regression models examined each eating frequency and timing exposure variable with C-reactive protein (CRP) concentrations and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). Each 10 percent increase in the proportion of calories consumed in the evening was associated with a 3 percent increase in CRP. Conversely, eating one additional meal or snack per day was associated with an 8 percent reduction in CRP. There was a significant interaction between proportion of calories consumed in the evening and fasting duration with CRP (p = 0.02). A longer nighttime fasting duration was associated with an 8 percent lower CRP only among women who ate less than 30% of their total daily calories in the evening (p = 0.01). None of the eating frequency and timing variables were significantly associated with HOMA-IR. These findings suggest that eating more frequently, reducing evening energy intake, and fasting for longer nightly intervals may lower systemic inflammation and subsequently reduce breast cancer risk. Randomized trials are needed to validate these associations

    Aspects of a biblical theology of womenhood

    Get PDF
    Philosophy, Practical and Systematic TheologyD.Th.(Systematic Theology

    The distribution of lead between sea salt dust, and lead-rich aerosols in the mid South Pacific easterlies at American Samoa

    Get PDF
    Aerosols in the South Pacific Easterlies have been sampled at American Samoa with a cascade impactor and analysed for Pb, Ba, K, Ca, Sr, and Rb by isotope dilution mass spectrometry using ultraclean procedures. Some 84% of the Pb was found in fine (≤ 0.5 μm) aerosols which were collected on the backup filter with an efficiency of only 33%. Sea salt and eroded terrestrial material (dust) containing 6% and <1% respectively, of the Pb (sea salt indexed by the metals K, Ca, Sr, and Rb and dust indexed by Ba) were collected on early stages of the impactor, although 65% of the dust, because of its larger size, was lost to surfaces of the rain shelter before reaching the impactor. The remaining 10% of the Pb was associated with plant leaf waxes of continental origin which produced Pb and Ba peaks on stage 4 (0.5 μ) of the impactor

    The Economics of Being Young and Poor: How Homeless Youth Survive in Neo-liberal Times

    Get PDF
    Based upon in-depth interviews with 34 youth in Halifax and seven service providers in St. John\u27s, Montreal, Hamilton, Toronto, Winnipeg, and Calgary, the findings of this study suggest that labor occurs within a particular street context and street culture. Formal and informal work can be inter-related, and despite the hardships they experience, young people who are homeless or who are at-risk of homelessness can respond to their circumstances with ingenuity, resilience and hope. Often street-involved and homeless young people are straddling formal and informal work economies while mediating layers of external and internal motivations and tensions. The reality is that the participants in this study cannot very easily engage in formal work. There is a dearth of meaningful formal work available, and when living homeless there are many challenges to overcome to maintain this work. In addition, there are few employers willing to risk hiring an individual who is without stable housing, previous employment experiences and, most likely, limited formal education. Therefore, street youth are left with informal work that provides them with survival money, basic needs, and a sense of citizenship, but which also invites belittlement, harassment, and mockery
    • …
    corecore