72 research outputs found
The Ursinus Weekly, October 17, 1974
N.A.B. named • Freshmen elect officers: Larry Dalaker president • Alumna corner: Color Day • Editorial • Bears are back • Letters to the editor: R.S.W. cut down; Wismer cut down; M.J.H. cut down; And again; Finally, thank you • Salinger myth dissolvedhttps://digitalcommons.ursinus.edu/weekly/1022/thumbnail.jp
Nutrient Supply and Mercury Dynamics in Marine Ecosystems: A Conceptual Model
There is increasing interest and concern over the impacts of mercury (Hg) inputs to marine 32 ecosystems. One of the challenges in assessing these effects is that the cycling and trophic 33 transfer of Hg are strongly linked to other contaminants and disturbances. In addition to Hg, a 34 major problem facing coastal waters is the impacts of elevated nutrient, particularly nitrogen 35 (N), inputs. Increases in nutrient loading alter coastal ecosystems in ways that should change 36 the transport, transformations and fate of Hg, including increases in fixation of organic carbon 37 and deposition to sediments, decreases in the redox status of sediments and changes in fish 38 habitat. In this paper we present a conceptual model which suggests that increases in loading 39 of reactive N to marine ecosystems might alter Hg dynamics, decreasing bioavailabilty and 40 trophic transfer. This conceptual model is most applicable to coastal waters, but may also be 41 relevant to the pelagic ocean. We present information from case studies that both support and 42 challenge this conceptual model, including marine observations across a nutrient gradient; 43 results of a nutrient‐trophic transfer Hg model for pelagic and coastal ecosystems; observations 44 of Hg species, and nutrients from coastal sediments in the northeastern U.S.; and an analysis of 45 fish Hg concentrations in estuaries under different nutrient loadings. These case studies suggest 46 that changes in nutrient loading can impact Hg dynamics in coastal and open ocean ecosystems. 47 Unfortunately none of the case studies is comprehensive; each only addresses a portion of the 48 conceptual model and has limitations. Nevertheless, our conceptual model has important 49 management implications. Many estuaries near developed areas are impaired due to elevated 50 nutrient inputs. Widespread efforts are underway to control N loading and restore coastal 51 ecosystem function. An unintended consequence of nutrient control measures could be to 3 exacerbate 52 problems associated with Hg contamination. Additional focused research and 53 monitoring are needed to critically examine the link between nutrient supply and Hg 54 contamination of marine waters
The Ursinus Weekly, November 21, 1974
Unenthusiastic review received for ProTheatre\u27s Antigone cast • CMP: Last year; 5 new courses added • NEPSA names Dr. E. H. Miller new president • Forest Green is coming • Letter to the editor • Culture on culture • Catharsis, Pepto-Bismol and the college weekend • Dr. Bludan Bones tells of weird Trappe tale • Advice to the lovelorn • The College Union has done it again • Kicks • Hockey team to England • Commitment?https://digitalcommons.ursinus.edu/weekly/1026/thumbnail.jp
MEASURING SULFIDE ACCUMULATION IN DIFFUSIVE GRADIENTS IN THIN FILMS BY MEANS OF PURGE AND TRAP FOLLOWED BY ION-SELECTIVE ELECTRODE
Abstract—A procedure for measuring in situ sulfide concentrations by coupling diffusive gradients in thin films (DGT) to solid-state ion-selective electrodes (ISE) is described and evaluated. Laboratory tests were performed to evaluate the coupling of these techniques, and these results were compared to the previously used methods of computer imaging densitometry (CID) and methylene blue. An average elution efficiency of 89%, as detected by ISE, was determined for a series of solutions containing amounts of sulfide ranging from 0.009 to 2.50 mmol. The validity of the standard mass-transfer equation for sulfide accumulation by DGT probes and subsequent detection by ISE was tested by measuring the mass of sulfide collected over time and with respect to varying diffusive gel thicknesses. Regressions of the sulfide mass accumulation versus the independent variables of time and inverse diffusive thickness proved to be linear. The use of DGT coupled to ISE provides a preconcentration method for sulfide that improves the detection limit (DL) over other techniques. This alternative method provides quantitative measurements of DGT-captured sulfide from solutions with a detection limit of at least 0.1 mmol/L for a 24-h deployment. The DGT technique also provides potential advantages in understanding sulfide speciation over existing methods. Keywords—Sulfide In situ Diffusive gradients Thin films Ion-selective electrod
The Ursinus Weekly, October 24, 1974
Profs to lecture on Pa. Dutch arts • Dr. Lodge joins U.C. Psych Dept. • Campus Chest plans for funds and fun • Forum features flute and guitar • Is there a ghost in U.C.\u27s haunted hall? • Letters to the editor: Students demand a good education • The origin of The Lantern • Alumni corner • An autumn walk • Mr. Richter goes to school • What\u27s playing at the movies? • Spectrum blues: Joe Cocker • Spanish Club plans outing • Campus Gold activities • Introducing campus leaders • Money given away • Ursinus Homecoming 1974: Fraternity candidates to wear the queen\u27s crown • Homecoming from Ursinus past • Union ripped-off • A football commentary • X-country: three in a rowhttps://digitalcommons.ursinus.edu/weekly/1023/thumbnail.jp
Brief motivational enhancement intervention to prevent or reduce postpartum alcohol use: a single-blinded, randomized controlled effectiveness trial
AIMS: The aim of this study is to assess the effect of brief motivational enhancement intervention postpartum alcohol use. DESIGN: This study is a single-blinded, randomized controlled effectiveness trial in which pregnant women were assigned to receive usual care or up to 5 face-to-face brief motivational enhancement sessions lasting 10-30 minutes each and occurring at study enrollment, 4 and 8 weeks after enrollment, 32 weeks of gestation, and 6 weeks postpartum. SETTING: The setting is in a large, urban, obstetrics clinic. PARTICIPANTS: Participants were women who were \u3e/= 18 years old,gestation, and consumed alcohol during pregnancy. Of 3438 women screened, 330 eligible women were assigned to usual care (n = 165) or intervention (n=165). Due to missing data, we analyzed 125 in the intervention group and 126 in the usual care group. MEASUREMENTS: The measurements were the proportion of women with any alcohol use and the number of drinks per day, reported via follow-up telephone interviews at 4 and 8 weeks after enrollment, 32 weeks of gestation, and 6 weeks, 6 months, and 12 months postpartum. FINDINGS: In random effects models adjusted for confounders, the intervention group was less likely to use any alcohol (odds ratio 0.50; 95% confidence interval [CI], 0.23-1.09; P=0.08) and consumed fewer drinks per day (coefficient -0.11; 95% CI -0.23-0.01; P=0.07) than, the usual care group in the postpartum period but these differences were non-significant. Missing data during the prenatal period prevented us from modeling prenatal alcohol use. CONCLUSIONS: Brief motivational enhancement intervention delivered in an obstetrical outpatient setting did not conclusively decrease alcohol use during the postpartum period
The Ursinus Weekly, November 7, 1974
The Great Pumpkin comes to U.C. • Course Directory Catalogue Committee formed by U.S.G.A. • Antigone is ProTheatre\u27s production • Union does it again • Criminal law featured as Forum topic • Letters to the editor: Epitaph on an Ursinus transfer • Pages from Ursinus past: A legend • Perusing Pfahler\u27s pigeons • New Economics head • Equus reviewed • Concerts: Bizarre and sublime • Record review • Nate DuPree: Can a black man find happiness at Ursinus? • Martha Franklin: A half century of service to our students and campus • Readin\u27, ritin\u27 and new math • Introducing campus leaders • Football wrapup: Swarthmore; Widener • Hockey teams win the big games! • Harriers 6-4 on seasonhttps://digitalcommons.ursinus.edu/weekly/1024/thumbnail.jp
Nutrient Supply and Mercury Dynamics in Marine Ecosystems: A Conceptual Model
There is increasing interest and concern over the impacts of mercury (Hg) inputs to marine ecosystems. One of the challenges in assessing these effects is that the cycling and trophic transfer of Hg are strongly linked to other contaminants and disturbances. In addition to Hg, a major problem facing coastal waters is the impacts of elevated nutrient, particularly nitrogen (N), inputs. Increases in nutrient loading alter coastal ecosystems in ways that should change the transport, transformations and fate of Hg, including increases in fixation of organic carbon and deposition to sediments, decreases in the redox status of sediments and changes in fish habitat. In this paper we present a conceptual model which suggests that increases in loading of reactive N to marine ecosystems might alter Hg dynamics, decreasing bioavailabilty and trophic transfer. This conceptual model is most applicable to coastal waters, but may also be relevant to the pelagic ocean. We present information from case studies that both support and challenge this conceptual model, including marine observations across a nutrient gradient; results of a nutrient‐trophic transfer Hg model for pelagic and coastal ecosystems; observations of Hg species, and nutrients from coastal sediments in the northeastern U.S.; and an analysis of fish Hg concentrations in estuaries under different nutrient loadings. These case studies suggest that changes in nutrient loading can impact Hg dynamics in coastal and open ocean ecosystems. Unfortunately none of the case studies is comprehensive; each only addresses a portion of the conceptual model and has limitations. Nevertheless, our conceptual model has important management implications. Many estuaries near developed areas are impaired due to elevated nutrient inputs. Widespread efforts are underway to control N loading and restore coastal ecosystem function. An unintended consequence of nutrient control measures could be to exacerbate problems associated with Hg contamination. Additional focused research and monitoring are needed to critically examine the link between nutrient supply and Hg contamination of marine waters
A consensus protocol for the recovery of mercury methylation genes from metagenomes
Mercury (Hg) methylation genes (hgcAB) mediate the formation of the toxic methylmercury and have been identified from diverse environments, including freshwater and marine ecosystems, Arctic permafrost, forest and paddy soils, coal-ash amended sediments, chlor-alkali plants discharges and geothermal springs. Here we present the first attempt at a standardized protocol for the detection, identification and quantification of hgc genes from metagenomes. Our Hg-cycling microorganisms in aquatic and terrestrial ecosystems (Hg-MATE) database, a catalogue of hgc genes, provides the most accurate information to date on the taxonomic identity and functional/metabolic attributes of microorganisms responsible for Hg methylation in the environment. Furthermore, we introduce "marky-coco", a ready-to-use bioinformatic pipeline based on de novo single-metagenome assembly, for easy and accurate characterization of hgc genes from environmental samples. We compared the recovery of hgc genes from environmental metagenomes using the marky-coco pipeline with an approach based on coassembly of multiple metagenomes. Our data show similar efficiency in both approaches for most environments except those with high diversity (i.e., paddy soils) for which a coassembly approach was preferred. Finally, we discuss the definition of true hgc genes and methods to normalize hgc gene counts from metagenomes
A Phase 1 Human Immunodeficiency Virus Vaccine Trial for Cross-Profiling the Kinetics of Serum and Mucosal Antibody Responses to CN54gp140 Modulated by Two Homologous Prime-Boost Vaccine Regimens
A key aspect to finding an efficacious human immunodeficiency virus (HIV) vaccine is the optimization of vaccine schedules that can mediate the efficient maturation of protective immune responses. In the present study, we investigated the effect of alternate booster regimens on the immune responses to a candidate HIV-1 clade C CN54gp140 envelope protein, which was coadministered with the TLR4-agonist glucopyranosyl lipid A-aqueous formulation. Twelve study participants received a common three-dose intramuscular priming series followed by a final booster at either 6 or 12 months. The two homologous prime-boost regimens were well tolerated and induced CN54gp140-specific responses that were observed in both the systemic and mucosal compartments. Levels of vaccine-induced IgG-subclass antibodies correlated significantly with Fc gamma R engagement, and both vaccine regimens were associated with strikingly similar patterns in antibody titer and Fc gamma R-binding profiles. In both groups, identical changes in the antigen (Ag)-specific IgG-subclass fingerprint, leading to a decrease in IgG1 and an increase in IgG4 levels, were modulated by booster injections. Here, the dissection of immune profiles further supports the notion that prime-boost strategies are essential for the induction of diverse Ag-specific HIV-1 responses. The results reported here clearly demonstrate that identical responses were effectively and safely induced by both vaccine regimens, indicating that an accelerated 6-month regimen could be employed for the rapid induction of immune responses against CN54gp140 with no apparent impact on the overall quality of the induced immune response. (This study has been registered at http://ClinicalTrials.gov under registration no.NCT01966900.
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