28 research outputs found

    Reconciliation of the carbon budget in the ocean’s twilight zone

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    Photosynthesis in the surface ocean produces approximately 100 gigatonnes of organic carbon per year, of which 5 to 15 per cent is exported to the deep ocean1, 2. The rate at which the sinking carbon is converted into carbon dioxide by heterotrophic organisms at depth is important in controlling oceanic carbon storage3. It remains uncertain, however, to what extent surface ocean carbon supply meets the demand of water-column biota; the discrepancy between known carbon sources and sinks is as much as two orders of magnitude4, 5, 6, 7, 8. Here we present field measurements, respiration rate estimates and a steady-state model that allow us to balance carbon sources and sinks to within observational uncertainties at the Porcupine Abyssal Plain site in the eastern North Atlantic Ocean. We find that prokaryotes are responsible for 70 to 92 per cent of the estimated remineralization in the twilight zone (depths of 50 to 1,000 metres) despite the fact that much of the organic carbon is exported in the form of large, fast-sinking particles accessible to larger zooplankton. We suggest that this occurs because zooplankton fragment and ingest half of the fast-sinking particles, of which more than 30 per cent may be released as suspended and slowly sinking matter, stimulating the deep-ocean microbial loop. The synergy between microbes and zooplankton in the twilight zone is important to our understanding of the processes controlling the oceanic carbon sink

    Motor-Cortical Interaction in Gilles de la Tourette Syndrome

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    BACKGROUND: In Gilles de la Tourette syndrome (GTS) increased activation of the primary motor cortex (M1) before and during movement execution followed by increased inhibition after movement termination was reported. The present study aimed at investigating, whether this activation pattern is due to altered functional interaction between motor cortical areas. METHODOLOGY/PRINCIPAL FINDINGS: 10 GTS-patients and 10 control subjects performed a self-paced finger movement task while neuromagnetic brain activity was recorded using Magnetoencephalography (MEG). Cerebro-cerebral coherence as a measure of functional interaction was calculated. During movement preparation and execution coherence between contralateral M1 and supplementary motor area (SMA) was significantly increased at beta-frequency in GTS-patients. After movement termination no significant differences between groups were evident. CONCLUSIONS/SIGNIFICANCE: The present data suggest that increased M1 activation in GTS-patients might be due to increased functional interaction between SMA and M1 most likely reflecting a pathophysiological marker of GTS. The data extend previous findings of motor-cortical alterations in GTS by showing that local activation changes are associated with alterations of functional networks between premotor and primary motor areas. Interestingly enough, alterations were evident during preparation and execution of voluntary movements, which implies a general theme of increased motor-cortical interaction in GTS

    A Retrospective Look at the U.S. Productivity Growth Resurgence

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    It is now widely recognized that information technology (IT) was critical to the dramatic acceleration of U.S. labor productivity growth in the mid-1990s. This paper traces the evolution of productivity estimates to document how and when this perception emerged. Early studies concluded that IT was relatively unimportant. It was only after the massive IT investment boom of the late 1990s that this investment and underlying productivity increases in the IT-producing sectors were identified as important sources of growth. Although IT has diminished in significance since the dot-com crash of 2000, we project that private sector productivity growth will average around 2.5 percent per year for the next decade, a pace that is only moderately below the average for the 1995-2005 period

    Prevalence and Associations, by Age Group, of IPV Among AGYW in Rural South Africa

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    The prevalence of intimate partner violence (IPV) is alarmingly high among South African adolescent girls and young women (AGYW). Limited data exist exploring how IPV prevalence and its risk factors differ by age. Study data were from the baseline visit of HPTN 068, a randomized controlled trial (RCT) conducted from 2011 to 2015 in Mpumalanga, South Africa. A cohort of 2,533 AGYW, aged 13 years to 20 years, answered survey questions on demographics and behaviors, including their experiences of physical and sexual violence ever and in the past 12 months. We calculated the prevalence of IPV and related risk factors, as well as prevalence ratios with 95% confidence intervals, stratified by age. Nearly one quarter (19.5%, 95% CI = [18.0, 21.2]) of AGYW experienced any IPV ever (physical or sexual) by a partner. The prevalence of any IPV ever among AGYW aged 13 years to 14 years, 15 years to 16 years, and 17 years to 20 years was 10.8%, 17.7%, and 32.1%, respectively. Key variables significantly associated with any IPV ever across all age groups included borrowing money from someone outside the home in the past 12 months, ever having had vaginal sex, ever having had anal sex, and consuming any alcohol. Few statistically significant associations were unique to specific age groups. The history of IPV among the youngest AGYW is a critical finding and should be a focus of prevention efforts

    Women’s and girls’ experiences of reproductive coercion and opportunities for intervention in family planning clinics in Nairobi, Kenya: A qualitative study

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    Background: Reproductive coercion (RC), which includes contraceptive sabotage and pregnancy coercion, may help explain known associations between intimate partner violence (IPV) and poor reproductive health outcomes, such as unintended pregnancy. In Kenya, where 40% of ever-married women report IPV and 35% of ever-pregnant women report unintended pregnancy, these experiences are pervasive and co-occurring, yet little research exists on RC experiences among women and adolescent girls. This study seeks to qualitatively describe women’s and girls’ experiences of RC in Nairobi, Kenya and opportunities for clinical intervention. Methods: Qualitative data were collected as part of the formative research for the adaptation of an evidence-based intervention to address reproductive coercion and IPV in clinical family planning counselling and provision in Nairobi, Kenya in April 2017. Focus group discussions (n = 4, 30 total participants) and in-depth interviews (n = 10) with family planning clients (ages 15–49) were conducted to identify specific forms of reproductive coercion, other partner-specific barriers to successful contraception use, and perceived opportunities for family planning providers to address RC among women and girls seeking family planning services. Additionally, data were collected via semi-structured interviews with family planning providers (n = 8) and clinic managers (n = 3) from family planning clinics. Data were coded according to structural and emergent themes, summarized, and illustrative quotes were identified to demonstrate sub-themes. Kenyan family planning providers and administrators informed interpretation. Results: The results of this study identified specific forms of pregnancy coercion and contraceptive sabotage to be common, and often severe, impeding the use of contraceptives among female family planning clients. This study offers important examples of women’s strategies for preventing pregnancy despite experiencing reproductive coercion, as well as opportunities for family planning providers to support clients experiencing reproductive coercion in clinical settings. Conclusions: Reproductive coercion is a critical barrier to modern contraceptive use in Kenya. Results from this study highlight opportunities for family planning providers to play a critical role in supporting women and girls in their use of contraception when reproductive coercion is present

    Risk Factors for Sporadic Cryptosporidiosis among Immunocompetent Persons in the United States from 1999 to 2001

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    Many studies have evaluated the role of Cryptosporidium spp. in outbreaks of enteric illness, but few studies have evaluated sporadic cryptosporidiosis in the United States. To assess the risk factors for sporadic cryptosporidiosis among immunocompetent persons, a matched case-control study was conducted in seven sites of the Foodborne Diseases Active Surveillance Network (FoodNet) involving 282 persons with laboratory-identified cryptosporidiosis and 490 age-matched and geographically matched controls. Risk factors included international travel (odds ratio [OR] = 7.7; 95% confidence interval [95% CI] = 2.7 to 22.0), contact with cattle (OR = 3.5; 95% CI = 1.8 to 6.8), contact with persons >2 to 11 years of age with diarrhea (OR = 3.0; 95% CI = 1.5 to 6.2), and freshwater swimming (OR = 1.9; 95% CI = 1.049 to 3.5). Eating raw vegetables was protective (OR = 0.5; 95% CI = 0.3 to 0.7). This study underscores the need for ongoing public health education to prevent cryptosporidiosis, particularly among travelers, animal handlers, child caregivers, and swimmers, and the need for further assessment of the role of raw vegetables in cryptosporidiosis

    Married very young adolescent girls in Niger at greatest risk of lifetime male partner reproductive coercion and sexual violence.

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    OBJECTIVE:The purpose of this analysis was to compare and contrast reproductive health (RH), gender equity attitudes, and intimate partner violence (IPV) among married very young adolescent (VYA) girls with married older adolescent girls and young women (AGYW) in rural Niger given limited literature on the topic. METHODS:We conducted an exploratory analysis of baseline data from the Reaching Married Adolescents Trial in Dosso region, Niger. We report counts and percents, by age group (13-14 years (VYA), 15-16 years, 17-19 years), of AGYW's self-efficacy to use family planning (FP), accurate knowledge of FP, current use of modern FP, and unintended last pregnancy (UIP); lifetime reproductive coercion (RC), physical IPV, and sexual IPV; and gender equity attitudes. We also assess whether percents differ between VYA and older groups using Pearson's Chi-Square and Fisher's exact p-values. Results are stratified by parity. Finally, we use logistic regression to consider associations. RESULTS:There were 49 VYA, 248 girls aged 15-16, and 775 AGYW aged 17-19 in our sample (n = 1072). Accurate knowledge of FP, self-efficacy to use FP, current use of modern FP, and UIP increased with age; all percents between VYA and AGYW 17-19 were marginally or statistically significantly different. We also saw VYA report higher lifetime RC and sexual IPV versus older groups, with sexual IPV statistically different between VYA and girls 17-19. Parous VYA reported a significantly higher percent of lifetime RC versus older AGYW. Among 17-19 year-olds, odds of current use of FP were higher among AGYW who reported physical IPV, and odds of UIP were higher among those reporting more gender equitable attitudes, both adjusted for parity. CONCLUSIONS:We observed differences in RH, RC, and sexual IPV among married VYA and older AGYW in rural Niger. VYA should be prioritized in research to confirm and further understand their RH needs
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