1,711 research outputs found

    Great Bay Nitrogen Non-Point Source Study

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    The Great Bay Estuary is 21 square miles of tidal waters located in southeastern New Hampshire. It is one of 28 “estuaries of national significance” established under the Environmental Protection Agency’s National Estuary Program. The estuary is experiencing the signs of eutrophication, specifically, low dissolved oxygen, macroalgae blooms, and declining eelgrass habitat (DES, 2012). Sixty-eight percent of the nitrogen that ends up in the Great Bay Estuary originates from sources spread across the watershed; the remainder derives from direct discharges of municipal wastewater treatment facilities (DES, 2010; PREP, 2013). In this report, these sources of nitrogen are called non-point sources and consist of atmospheric deposition, fertilizers, human waste disposed into septic systems, and animal waste. The purpose of this study is to determine how much nitrogen each non-point source type contributes to the estuary. The nitrogen loads from municipal wastewater treatment facilities have been reported elsewhere (DES, 2010; PREP, 2012; PREP, 2013) and, therefore, are not included in this study except to provide context. The intended use of this study is for planning purposes, and is not meant for regulatory allocations or specific reduction requirements. The results of the model may be useful for towns or watershed groups for prioritizing nitrogen reduction efforts or as a starting point for more detailed studies of non-point sources. However, more detailed inventories of non-point sources will be needed to track the effects of nitrogen reduction efforts in smaller areas. In addition, the model makes no conclusions about the benefits of nitrogen reductions to receiving waters or overall estuarine health

    Bubble thy neighbour: Portfolio effects and externalities from capital controls

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    We use changes in Brazil's tax on capital inflows from 2006 to 2013 to test for direct portfolio effects and externalities from capital controls on investor portfolios. We find that an increase in Brazil's tax on foreign investment in bonds causes fund managers to significantly decrease their portfolio allocations to Brazil in both bonds and equities. Fund managers simultaneously increase allocations to other countries that have substantial exposure to China and decrease allocations to countries viewed as more likely to adjust their capital controls. Much of the effect of capital controls on portfolio allocation appears to occur through signalling — i.e., changes in investor expectations about future policies — rather than the direct cost of the controls. This evidence of significant externalities from capital controls suggests that any assessment of controls should consider their effects on portfolio flows to other countries. Keywords: Capital controls; Externalities; Spillovers; Signalling; Mutual funds; Brazi

    Is Stent Placement Effective for Palliation of Right Ventricle to Pulmonary Artery Conduit Stenosis?

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    ObjectivesThis study was designed to evaluate the outcome of stent placement (SP) for conduit discrete stenosis using predefined criteria.BackgroundRight ventricle (RV) to pulmonary artery (PA) conduits are often associated with complications, such as stenosis, requiring multiple surgical replacements.MethodsPatients who underwent primary or repeat SP were included. Indications for SP were clinical symptoms and/or RV to systolic blood pressure (SBP) ratio (RV:SBP) >0.65 by echocardiography. Our definition of success was a decrease in RV:SBP by >20%, a final RV:SBP ratio of <0.65, or resolution of symptoms.ResultsStents were placed successfully in 28 of 31 patients (90%), including 3 patients who underwent the procedure solely for symptoms. The RV:SBP ratio decreased (0.75 ± 0.17 vs. 0.52 ± 0.12, p < 0.001), and the conduit diameter increased (postero-anterior 9.1 ± 2.9 vs. 12.0 ± 2.8 mm, lateral 8.3 ± 2.2 vs. 11.6 ± 2.4 mm, p < 0.001). In the 28 patients with successful SP, 8 (29%) remained free from second intervention. In the remaining patients, the median time to re-intervention was 16 months (range 6 to 44 months). Second transcatheter interventions (4 SP, 4 balloon dilation) were successful in 8 of 13 patients. Complications included balloon rupture (n = 4), stent fracture (n = 2), and pseudoaneurysm formation (n = 1).ConclusionsInitial SP has excellent intermediate outcomes, successfully postponing surgical intervention for the majority of patients. Conduit restenosis may be successfully treated with a second transcatheter intervention. On the basis of these data, SP is likely the procedure of choice for patients with a discrete stenosis of the RV to PA conduit

    Bioelectrical Impedance Analysis (BIA)-derived Phase Angle (PA) is a practical aid to nutritional assessment in hospital in-patients

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    Background: Nutritional status can be difficult to assess. Bioelectrical impedance analysis (BIA)-derived phase angle (PA), and the plasma markers citrulline and transthyretin (pre-albumin) have the potential to assist, but the protocol of fasting and resting for BIA renders the investigation impractical for routine use, especially so in populations at high risk of malnutrition.  Aims: 1- To clarify whether starving and resting are necessary for reliable measurement of PA. 2- To identify whether PA, citrulline and transthyretin correlate with nutritional status.  Methods: Eighty consenting adult in-patients were recruited. Nutritional status was determined by subjective global assessment (SGA) used as gold standard. The Malnutrition Universal Screening Tool (MUST) was used and anthropometric measurements were performed. Serum was analysed for citrulline and transthyretin. PA was measured using Bodystat 4000. The PA was considered to define malnutrition when lower than reference ranges for sex and age, and severe malnutrition if more than 2 integers below the lower limit. Anthropometric measurements were categorised according to WHO reference centiles. Ordinal logistic regression estimated the strength of association of PA, citrulline and transthyretin with SGA. PA values in the different metabolic states were compared using paired t tests.  Results: All 80 subjects completed the BIA and the nutritional assessments in the 3 different states; 14 declined to provide blood samples for the biochemical assays. Malnutrition was identified in 32 cases, severe malnutrition in 14 cases, the remaining 34 cases were deemed not to be malnourished. PA was strongly inversely associated with SGA (Odds Ratio [OR] per unit increase = 0.21, CI 0.12-0.37, p < 0.001). PA was not influenced by exercise (p=0.134) or food intake (p=0.184). Transthyretin was inversely associated with malnourished/severely malnourished states (OR = 0.98, 95% CI 0.97 – 0.99, p = 0.001), but had poorer predictive values than PA. There was no significant association between citrulline concentration and SGA (OR = 1.01, 95% CI 0.99-1.04, p = 0.348).  Conclusions: The BIA-derived PA reliably identifies malnutrition. It is strongly associated with SGA but requires less skill and experience, and out-performs circulating transthyretin, rendering it a promising and less operator-dependent tool for assessing nutritional status in hospital patients. Our novel demonstration that fasting and bed-rest are unnecessary consolidates that position

    Dynamical Evolution of Globular Clusters in Hierarchical Cosmology

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    We probe the evolution of globular clusters that could form in giant molecular clouds within high-redshift galaxies. Numerical simulations demonstrate that the large and dense enough gas clouds assemble naturally in current hierarchical models of galaxy formation. These clouds are enriched with heavy elements from earlier stars and could produce star clusters in a similar way to nearby molecular clouds. The masses and sizes of the model clusters are in excellent agreement with the observations of young massive clusters. Do these model clusters evolve into globular clusters that we see in our and external galaxies? In order to study their dynamical evolution, we calculate the orbits of model clusters using the outputs of the cosmological simulation of a Milky Way-sized galaxy. We find that at present the orbits are isotropic in the inner 50 kpc of the Galaxy and preferentially radial at larger distances. All clusters located outside 10 kpc from the center formed in the now-disrupted satellite galaxies. The spatial distribution of model clusters is spheroidal, with a power-law density profile consistent with observations. The combination of two-body scattering, tidal shocks, and stellar evolution results in the evolution of the cluster mass function from an initial power law to the observed log-normal distribution.Comment: 5 pages, proceedings of IAU 246 "Dynamical Evolution of Dense Stellar Systems", eds. Vesperini, Giersz, Sill

    The SLUGGS Survey: Calcium Triplet-based Spectroscopic Metallicities for Over 900 Globular Clusters

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    Although the colour distribution of globular clusters in massive galaxies is well known to be bimodal, the spectroscopic metallicity distribution has been measured in only a few galaxies. After redefining the calcium triplet index-metallicity relation, we use our relation to derive the metallicity of 903 globular clusters in 11 early-type galaxies. This is the largest sample of spectroscopic globular cluster metallicities yet assembled. We compare these metallicities with those derived from Lick indices finding good agreement. In 6 of the 8 galaxies with sufficient numbers of high quality spectra we find bimodality in the spectroscopic metallicity distribution. Our results imply that most massive early-type galaxies have bimodal metallicity, as well as colour, distributions. This bimodality suggests that most massive galaxies early-type galaxies experienced two periods of star formation.Comment: 23 pages, 13 figures. Accepted for publication in MNRAS. For more information about the SLUGGS Survey please see http://sluggs.swin.edu.a

    Effectiveness of herpes zoster vaccination in an older United Kingdom population.

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    BACKGROUND: Vaccination against herpes zoster was introduced in the United Kingdom in 2013 for individuals aged 70 years, with a phased catch-up campaign for 71-79 year olds. Vaccine introduction has resulted in a marked fall in incident herpes zoster and in post-herpetic neuralgia (PHN), but formal evaluation of vaccine effectiveness is needed. METHODS: In a population-based cohort study of older individuals born between 1933 and 1946, we used linked UK anonymised primary care health records for the first three years of the vaccination programme (01/09/2013-31/08/2016) and multivariable Poisson regression to obtain incidence rates and vaccine effectiveness (VE) against zoster and PHN. RESULTS: Among 516,547 individuals, 21% were vaccinated. Incidence of zoster was 3.15/1000 person-years in vaccinees and 8.80/1000 person-years in unvaccinated individuals. After adjustment, VE was 64% (95%CI = 60-68%) against incident zoster and 81% (95%CI = 61-91%) against PHN, with very similar VE estimates in the routine and catch-up cohorts. VE against zoster was lower in those with a previous history of zoster: 47% (95%CI = 31-58%) versus 64% (95%CI = 60-68%) in those without previous zoster. There was evidence of waning VE over time, from 69% (95%CI = 65-74%) in the first year after vaccination to 45% (95%CI = 29-57%) by the third year. CONCLUSION: This first formal assessment of VE in the UK zoster vaccination programme demonstrates good effectiveness of zoster vaccine, and very good protection against PHN. The findings provide evidence that VE is similar across the age groups targeted for vaccination in the UK, and on duration of protection of the vaccine in public health use. The study provides key information for decision-makers about the future direction of UK zoster vaccination programme, indicating that the live zoster vaccine may be more cost-effective than estimated previously. It also supports efforts to communicate the benefits of zoster vaccination to address the declining coverage observed across the UK
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