253 research outputs found

    Spring–summer net community production, new production, particle export and related water column biogeochemical processes in the marginal sea ice zone of the Western Antarctic Peninsula 2012–2014

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    New production (New P, the rate of net primary production (NPP) supported by exogenously supplied limiting nutrients) and net community production (NCP, gross primary production not consumed by community respiration) are closely related but mechanistically distinct processes. They set the carbon balance in the upper ocean and define an upper limit for export from the system. The relationships, relative magnitudes and variability of New P (from 15NO3– uptake), O2 : argon-based NCP and sinking particle export (based on the 238U : 234Th disequilibrium) are increasingly well documented but still not clearly understood. This is especially true in remote regions such as polar marginal ice zones. Here we present a 3-year dataset of simultaneous measurements made at approximately 50 stations along the Western Antarctic Peninsula (WAP) continental shelf in midsummer (January) 2012–2014. Net seasonal-scale changes in water column inventories (0–150 m) of nitrate and iodide were also estimated at the same stations. The average daily rates based on inventory changes exceeded the shorter-term rate measurements. A major uncertainty in the relative magnitude of the inventory estimates is specifying the start of the growing season following sea-ice retreat. New P and NCP(O2) did not differ significantly. New P and NCP(O2) were significantly greater than sinking particle export from thorium-234. We suggest this is a persistent and systematic imbalance and that other processes such as vertical mixing and advection of suspended particles are important export pathways

    Methods Of Use Of An Online Economics Textbook

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    The rising cost of college textbooks over the last decade provides an opportunity for alternatives. Electronic or online textbooks are an effective substitute to the traditional paper-based textbooks, although students have been slow to transition to the new method. A custom, professor-written online textbook not only addresses the reduction in cost, but also creates a better connection to the material in the course and allows for frequent updates and error corrections. Issues related to reading an online textbook are explored and evidence of methods of student use of the text is provided

    Using Technology To Provide An Online Economics Textbook

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    College textbook costs have risen in the last decade. The development and use of encyclopedic introductory textbooks creates higher monetary cost for students. One method to lower costs is a custom, professor-written online textbook. Issues related to reading an online textbook are explored and future research discussed

    Height and risk of death among men and women: aetiological implications of associations with cardiorespiratory disease and cancer mortality

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    OBJECTIVES: Height is inversely associated with cardiovascular disease mortality risk and has shown variable associations with cancer incidence and mortality. The interpretation of findings from previous studies has been constrained by data limitations. Associations between height and specific causes of death were investigated in a large general population cohort of men and women from the West of Scotland. DESIGN: Prospective observational study. SETTING: Renfrew and Paisley, in the West of Scotland. SUBJECTS: 7052 men and 8354 women aged 45-64 were recruited into a study in Renfrew and Paisley, in the West of Scotland, between 1972 and 1976. Detailed assessments of cardiovascular disease risk factors, morbidity and socioeconomic circumstances were made at baseline. MAIN OUTCOME MEASURES: Deaths during 20 years of follow up classified into specific causes. RESULTS: Over the follow up period 3347 men and 2638 women died. Height is inversely associated with all cause, coronary heart disease, stroke, and respiratory disease mortality among men and women. Adjustment for socioeconomic position and cardiovascular risk factors had little influence on these associations. Height is strongly associated with forced expiratory volume in one second (FEV1) and adjustment for FEV1 considerably attenuated the association between height and cardiorespiratory mortality. Smoking related cancer mortality is not associated with height. The risk of deaths from cancer unrelated to smoking tended to increase with height, particularly for haematopoietic, colorectal and prostate cancers. Stomach cancer mortality was inversely associated with height. Adjustment for socioeconomic position had little influence on these associations. CONCLUSION: Height serves partly as an indicator of socioeconomic circumstances and nutritional status in childhood and this may underlie the inverse associations between height and adulthood cardiorespiratory mortality. Much of the association between height and cardiorespiratory mortality was accounted for by lung function, which is also partly determined by exposures acting in childhood. The inverse association between height and stomach cancer mortality probably reflects Helicobacter pylori infection in childhood resulting inor being associated withshorter height. The positive associations between height and several cancers unrelated to smoking could reflect the influence of calorie intake during childhood on the risk of these cancers

    Expanded Understanding of the Western Antarctic Peninsula Sea-Ice Environment Through Local and Regional Observations at Palmer Station

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    The Western Antarctic Peninsula (WAP) has been experiencing rapid regional warming since at least the 1950s, however, the impacts of this warming at the local scale are variable and nuanced. Previous studies that have linked sea-ice variability to biogeochemical cycles and food web dynamics often combine local-scale biogeochemical data with coarse-resolution regional satellite sea-ice data, which may not adequately capture local sea-ice conditions. In this study, we analyzed local-scale in situ sea-ice observations collected as part of a 28-year record (1992–2020) from the Palmer Long-Term Ecological Research site at Anvers Island, mid-WAP, in conjunction with isotopically-derived sea-ice meltwater (SIM) fractions and satellite-derived sea-ice motion and concentration, to quantify the variability and long-term trends in local sea-ice behavior. In situ sea ice observations at Palmer Station displayed higher variability than satellite observations and showed no significant declines over this time, despite region-wide declines identified in prior studies. Higher spring SIM fractions were attributed to strong northward sea-ice motion throughout the winter. Applying these local-scale sea-ice insights to similarly scaled stratification and chlorophyll-a measurements, we found that a longer-lasting, more consistent sea-ice pack led to greater water column stratification following the spring sea-ice retreat. Greater sea-ice persistence and stronger stratification led to larger peaks in chlorophyll-a, though sea-ice metrics did not explain the positive temporal trends in either stratification strength or chlorophyll-a. Through this study, we identify how local sea-ice observations and meltwater data can enhance satellite data to build an understanding of the intricate connections between ice, water column dynamics, and phytoplankton

    Linking patterns of net community production and marine microbial community structure in the western North Atlantic

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    Marine net community production (NCP) tracks uptake of carbon by plankton communities and its potential transport to depth. Relationships between marine microbial community composition and NCP currently remain unclear despite their importance for assessing how different taxa impact carbon export. We conducted 16 and 18S rRNA gene (rDNA) sequencing on samples collected across the Western North Atlantic in parallel with high-resolution O2/Ar-derived NCP measurements. Using an internal standard technique to estimate in-situ prokaryotic and eukaryotic rDNA abundances per liter, we employed statistical approaches to relate patterns of microbial diversity to NCP. Taxonomic abundances calculated using internal standards provided valuable context to traditional relative abundance metrics. A bloom in the Mid-Atlantic Bight featured high eukaryote abundances with low eukaryotic diversity and was associated with the harmful algal bloom-forming Aureococcus anophagefferens, phagotrophic algae, heterotrophic flagellates, and particle-associated bacteria. These results show that coastal Aureococcus blooms host a distinct community associated with regionally significant peaks in NCP. Meanwhile, weak relationships between taxonomy and NCP in less-productive waters suggest that productivity across much of this region is not linked to specific microplankton taxa

    Variables affecting the probability of complete fusion of the medial clavicular epiphysis

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    In this study, we have combined data on clavicle fusion from different studies and applied a binomial logistic regression analysis. As such, we aimed to assess whether or not variables such as sex, socioeconomic status, and ethnicity influence the probability of having mature, i.e., completely fused clavicles at a given age. We further explored whether the method of clavicle examination, i.e., diagnosis from either a dry bone specimen, an examination of X-rays, or an examination of computed tomography scans, affects the probability of being diagnosed with mature clavicles. It appeared that only ethnicity did not significantly affect this probability. Finally, we illustrated how the logit model may be used to predict the probability of being diagnosed with mature clavicles

    The Iowa Homemaker vol.3, no.12

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    Table of Contents A Greeting to Iowa Homemakers by Dr. Louise Stanley, page 3 A New Book on “Meal Planning and Table Service” by Florence E. Busse, page 4 A Bill of Rights for the Child by Lulu R. Lancaster, page 4 Shrubs as a Garden Background by Juanita Beard, page 5 ‘Tis Egg Time Again by Beth Bailey McLean, page 6 The New Domestic System by Claude L. Benner, page 7 A Time Budget for the Homemaker by Ruth M. Lindquist, page 8 Figures That Do Not Lie by Mae L. Kelley, page 9 The Cooking of Meats by P. Mabel Nelson, page 10 The Psychology of Clothing by Eveleth Pedersen, page 11 Iowa State Women in Rural Schools by W. H. Lancelot, page 12 A Yarn about Yarns by Irene Christian, page 13 Tea Room Accounting by George M. Fuller, page 14 Who’s There and Where by Dryden Quist, page 15 Editorial, page 16 Homemaker as Citizen, page 17 The Eternal Question, page 18 Mrs. Purchaser Chooses Upholstery by Lucile Barta, page 1

    An Energy-Saving Development Initiative Increases Birth Rate and Childhood Malnutrition in Rural Ethiopia

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    BACKGROUND: Evolutionary life history theory predicts that, in the absence of contraception, any enhancement of maternal condition can increase human fertility. Energetic trade-offs are likely to be resolved in favour of maximizing reproductive success rather than health or longevity. Here we find support for the hypothesis that development initiatives designed to improve maternal and child welfare may also incur costs associated with increased family sizes if they do not include a family planning component. METHODS AND FINDINGS: Demographic and anthropometric data were collected in a rural Ethiopian community benefiting from a recent labour-saving development technology that reduces women's energetic expenditure ( n = 1,976 households). Using logistic hazards models and general linear modelling techniques, we found that whilst infant mortality has declined, the birth rate has increased, causing greater scarcity of resources within households. CONCLUSIONS: This study is, to our knowledge, the first to demonstrate a link between a technological development intervention and an increase in both birth rate and childhood malnutrition. Women's nutritional status was not improved by the energy-saving technology, because energy was diverted into higher birth rates. We argue that the contribution of biological processes to increased birth rates in areas of the developing world without access to modern contraception has been overlooked. This highlights the continued need for development programmes to be multisectoral, including access to and promotion of contraception

    Association of Serum Albumin with Markers of Nutritional Status among HIV-Infected and Uninfected Rwandan Women

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    The objectives of this study are to address if and how albumin can be used as an indication of malnutrition in HIV infected and uninfected Africans.In 2005, 710 HIV-infected and 226 HIV-uninfected women enrolled in a cohort study. Clinical/demographic parameters, CD4 count, albumin, liver transaminases; anthropometric measurements and Bioelectrical Impedance Analysis (BIA) were performed. Malnutrition outcomes were defined as body mass index (BMI), Fat-free mass index (FFMI) and Fat mass index (FMI). Separate linear predictive models including albumin were fit to these outcomes in HIV negative and HIV positive women by CD4 strata (CD4>350,200-350 and <200 cells/µl).In unadjusted models for each outcome in HIV-negative and HIV positive women with CD4>350 cells/µl, serum albumin was not significantly associated with BMI, FFMI or FMI. Albumin was significantly associated with all three outcomes (p<0.05) in HIV+ women with CD4 200-350 cells/µl, and highly significant in HIV+ women with CD4<200 cells/µl (P<0.001). In multivariable linear regression, albumin remained associated with FFMI in women with CD4 count<200 cells/µl (p<0.01) but not in HIV+ women with CD4>200.While serum albumin is widely used to indicate nutritional status it did not consistently predict malnutrition outcomes in HIV- women or HIV+ women with higher CD4. This result suggests that albumin may measure end stage disease as well as malnutrition and should not be used as a proxy for nutritional status without further study of its association with validated measures
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