Available nitrogen and phosphorus and the biochemical cycle in the Atlantic off New England

The importance of ammonia as a sourc:e of available nitrogen for phytoplanktonic populations off New England has been evaluated for August and January 1962. During August, when only trace amounts of nitrate persist in the photic layer, ammonia appears to be the major source of available nitrogen. Therefore, meaningful estimates of the relative amounts of nitrogen and phosphorus being assimilated at such times require consideration of the nitrogen occurring as ammonia...

The annual cycle of phosphorus and nitrogen in New England coastal waters

Distributions of phosphorus and nitrogen in New England coastal waters at various times of year are described. In surface waters the nitrate-nitrogen content is sometimes completely exhausted, even though small concentrations (0.2-0.5µg-at/l) of phosphorus are always available. The ratio of concentrations by atoms, N:P, varies in surface waters from maximum values of about 10: 1 to values approaching zero as the nitrate is exhausted...

Copper complexation during spring phytoplankton blooms in coastal waters

Cupric ion bioassays were conducted throughout the spring phytoplankton bloom season at two stations-one estuarine, dominated by dinoflagellates, the other coastal, dominated by diatoms. Copper-complexing ligands were detected at both locations throughout this period. Ligand concentrations varied between 0.1 and 0.75 μM, with the estuarine concentrations typically 2–4 times higher than coastal values. Ligands from both locations were destroyed by UV-oxidation and had similar conditional stability constants (range 108.3 to 109.2) that were significantly correlated with pH, suggesting that the complexing materials are organic chelators with weak acid functional groups. All measured or calculated parameters (DOC, ligand concentration, total copper concentration, salinity, and pH) remained relatively constant at the coastal station through time. The estuarine station was more dynamic, with DOC, total copper, and ligand concentrations varying 2–4 fold during the study. Although ligand concentrations were significantly different between the two locations, concomitant fluctuations in total dissolved copper and conditional stability constants resulted in a relatively constant estimate of the maximum free cupric ion activity at both stations (near 10–11 M). This suggests that copper toxicity alone was not responsible for the distinctly different estuarine and nearshore phytoplankton assemblages, although sensitive species might have been inhibited at both locations. Major phytoplankton blooms at both sites were not accompanied by changes in DOC or complexation capacity. A significant inverse correlation between ligand concentration and salinity suggests a terrestrial or sedimentary origin for the copper-complexing compounds

A clinical prediction model for long-term functional outcome after traumatic spinal cord injury based on acute clinical and imaging factors.

To improve clinicians\u27 ability to predict outcome after spinal cord injury (SCI) and to help classify patients within clinical trials, we have created a novel prediction model relating acute clinical and imaging information to functional outcome at 1 year. Data were obtained from two large prospective SCI datasets. Functional independence measure (FIM) motor score at 1 year follow-up was the primary outcome, and functional independence (score ≥ 6 for each FIM motor item) was the secondary outcome. A linear regression model was created with the primary outcome modeled relative to clinical and imaging predictors obtained within 3 days of injury. A logistic model was then created using the dichotomized secondary outcome and the same predictor variables. Model validation was performed using a bootstrap resampling procedure. Of 729 patients, 376 met the inclusion criteria. The mean FIM motor score at 1 year was 62.9 (±28.6). Better functional status was predicted by less severe initial American Spinal Injury Association (ASIA) Impairment Scale grade, and by an ASIA motor score \u3e50 at admission. In contrast, older age and magnetic resonance imaging (MRI) signal characteristics consistent with spinal cord edema or hemorrhage predicted worse functional outcome. The linear model predicting FIM motor score demonstrated an R-square of 0.52 in the original dataset, and 0.52 (95% CI 0.52,0.53) across the 200 bootstraps. Functional independence was achieved by 148 patients (39.4%). For the logistic model, the area under the curve was 0.93 in the original dataset, and 0.92 (95% CI 0.92,0.93) across the bootstraps, indicating excellent predictive discrimination. These models will have important clinical impact to guide decision making and to counsel patients and families

Circulating microRNAs in sera correlate with soluble biomarkers of immune activation but do not predict mortality in ART treated individuals with HIV-1 infection: A case control study

Introduction: The use of anti-retroviral therapy (ART) has dramatically reduced HIV-1 associated morbidity and mortality. However, HIV-1 infected individuals have increased rates of morbidity and mortality compared to the non-HIV-1 infected population and this appears to be related to end-organ diseases collectively referred to as Serious Non-AIDS Events (SNAEs). Circulating miRNAs are reported as promising biomarkers for a number of human disease conditions including those that constitute SNAEs. Our study sought to investigate the potential of selected miRNAs in predicting mortality in HIV-1 infected ART treated individuals. Materials and Methods: A set of miRNAs was chosen based on published associations with human disease conditions that constitute SNAEs. This case: control study compared 126 cases (individuals who died whilst on therapy), and 247 matched controls (individuals who remained alive). Cases and controls were ART treated participants of two pivotal HIV-1 trials. The relative abundance of each miRNA in serum was measured, by RTqPCR. Associations with mortality (all-cause, cardiovascular and malignancy) were assessed by logistic regression analysis. Correlations between miRNAs and CD4+ T cell count, hs-CRP, IL-6 and D-dimer were also assessed. Results: None of the selected miRNAs was associated with all-cause, cardiovascular or malignancy mortality. The levels of three miRNAs (miRs -21, -122 and -200a) correlated with IL-6 while miR-21 also correlated with D-dimer. Additionally, the abundance of miRs -31, -150 and -223, correlated with baseline CD4+ T cell count while the same three miRNAs plus miR- 145 correlated with nadir CD4+ T cell count. Discussion: No associations with mortality were found with any circulating miRNA studied. These results cast doubt onto the effectiveness of circulating miRNA as early predictors of mortality or the major underlying diseases that contribute to mortality in participants treated for HIV-1 infection

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

Report on a survey of the chemistry and hydrography of Great South Bay and Moriches Bay : made in June, 1957 for the Town of Islip, New York

Originally issued as Reference No. 57-59, series later renamed WHOI-.At the request of the Township of Islip, a chemical and biological survey of Great South Bay and Moriches Bay was conducted by the Woods Hole Oceanographic Institution during the summer of 1957. The survey duplicated to a large extent those which have been made annually by this Institution since 1950. Due to previous commitments :of the scientists, the 1957 survey was made during June 24-25 rather than in late August, when the earlier studies were conducted. Water samples were taken for both direct and subsequent laboratory analyses from the same locations as in the earlier surveys, consisting of a line of 17 stations located approximately along the central channel from Fire Island Inlet, at the western end of Great South Bay, to Westhampton, at the eastern end of Moriches Bay. Eleven additional stations were occupied along the northern side of the embayments in the various coves, creeks and rivers which had earlier been found to contribute to the pollution of the bay waters. Station locations are shown in Figure 1. The survey was conducted from a boat provided by the New York State Department of Conservation, and the authors wish to acknowledge their generous assistance. Much credit is also due to Mssrs. G. H. Vanderborgh, Sr. and Jr., Mr. Joseph Glancy, Mr. Samuel Cross, and Mr. Kenneth Mockridge for their valuable help before and during the survey, and for making available the seasonal data on salinity, rainfall, and winds which were used in the preparation of this report