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1.
Injury ; 55(8): 111597, 2024 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-38878381

RESUMEN

OBJECTIVES: The goal of this trial was to determine whether coronal plane angulation affects functional and clinical outcomes after the fixation of distal femur fractures. DESIGN: Multicenter, randomized controlled trial SETTING: 20 academic trauma centers PATIENTS/PARTICIPANTS: 156 patients with distal femur fractures were enrolled. 123 patients were followed 12 months. There was clinical outcome data available for 105 patients at 3 months, 95 patients at 6 months and 81 patients at one year. INTERVENTION: Lateral locked plating or retrograde intramedullary nailing MAIN OUTCOME MEASUREMENTS: Radiographic alignment, functional scoring including SMFA, Bother Index, and EQ-5D. Clinical scoring of walking ability, need for ambulatory support and ability to manage stairs. RESULTS: At 3 months, there was no difference between groups (varus, neutral or valgus) with respect to any of the clinical functional outcome scores measured. At 6 months, compared to those with neutral alignment, patients with varus angulation had a worse Stair Climbing score (4.33 vs. 2.91, p = 0.05). At 12 months, the average patient with neutral or valgus alignment needed less ambulatory support than the average patient in varus. Walking distance ability was no different between the groups at any time point. With respect to the validated patient-based outcome scores, we found no statistical difference in in the SMFA, Bother, or EQ-5D between patients with valgus or varus mal-alignment and those with neutral alignment at any time point (p > 0.05). Regardless of coronal angulation, the SMFA trended towards lower (improved) scores over time, while EQ-5D scores for patients with varus angulation did not improve over time. CONCLUSIONS: Valgus angulation and neutral angulation may be better tolerated in terms of clinical outcomes like stair climbing and need for ambulatory support than varus angulation, though patient reported outcome measures like the SMFA, Bother Index and EQ-5D show no statistical significance. Most patients with distal femur fractures tend to improve during the first year after injury but many remain significantly affected at 12 months post injury.

2.
Afr J Prim Health Care Fam Med ; 15(1): e1-e2, 2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37403677

RESUMEN

No abstract available.


Asunto(s)
Salud Global , Humanos , Objetivos
3.
J Glob Health ; 12: 04090, 2022 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-36462201

RESUMEN

Background: Digital health solutions are a potent and complementary intervention in health system strengthening to accelerate universal access to health services. Implementing scalable, sustainable, and integrated digital solutions in a coordinated manner is necessary to experience the benefits of digital interventions in health systems. We sought to establish the breadth and scope of available digital health interventions (DHIs) and their functions in sub-Saharan Africa. Methods: We conducted a scoping review according to the Joanne Briggs Institute's reviewers manual and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - Extension for Scoping Reviews (PRISMA-ScR) checklist and explanation. We retrieved data from the WHO Digital Health Atlas (DHA), the WHO e-Health country profiles report of 2015, and electronic databases. The protocol has been deposited in an open-source platform - the Open Science Framework at https://osf.io/5kzq7. Results: The researchers retrieved 983 digital tools used to strengthen health systems in sub-Saharan Africa over the past 10 years. We included 738 DHIs in the analysis while 245 were excluded for not meeting the inclusion criteria. We observed a disproportionate distribution of DHIs towards service delivery (81.7%, n = 603), health care providers (91.8%, n = 678), and access and use of information (84.1%, n = 621). Fifty-three percent (53.4%, n = 394) of the solutions are established and 47.5% (n = 582) were aligned to 20% (n = 5) of the system categories. Conclusions: Sub-Saharan Africa is endowed with digital health solutions in both numbers and distinct functions. It is lacking in coordination, integration, scalability, sustainability, and equitable distribution of investments in digital health. Digital health policymakers in sub-Saharan Africa need to urgently institute coordination mechanisms to terminate unending duplication and disjointed vertical implementations and manage solutions for scale. Central to this would be to build digital health leadership in countries within SSA, adopt standards and interoperability frameworks; advocate for more investments into lagging components, and promote multi-purpose solutions to halt the seeming "e-chaos" and progress to sustainable e-health solutions.


Asunto(s)
Asistencia Médica , Telemedicina , Humanos , África del Sur del Sahara , Programas de Gobierno , Personal de Salud
4.
Bull World Health Organ ; 100(1): 40-49, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-35017756

RESUMEN

OBJECTIVE: To assess the availability and gaps in data for measuring progress towards health-related sustainable development goals and other targets in selected low- and middle-income countries. METHODS: We used 14 international population surveys to evaluate the health data systems in the 47 least developed countries over the years 2015-2020. We reviewed the survey instruments to determine whether they contained tools that could be used to measure 46 health-related indicators defined by the World Health Organization. We recorded the number of countries with data available on the indicators from these surveys. FINDINGS: Twenty-seven indicators were measurable by the surveys we identified. The two health emergency indicators were not measurable by current surveys. The percentage of countries that used surveys to collect data over 2015-2020 were lowest for tuberculosis (2/47; 4.3%), hepatitis B (3/47; 6.4%), human immunodeficiency virus (11/47; 23.4%), child development status and child abuse (both 13/47; 27.7%), compared with safe drinking water (37/47; 78.7%) and births attended by skilled health personnel (36/47; 76.6%). Nineteen countries collected data on 21 or more indicators over 2015-2020 while nine collected data on no indicators; over 2018-2020 these numbers reduced to six and 20, respectively. CONCLUSION: Examining selected international surveys provided a quick summary of health data available in the 47 least developed countries. We found major gaps in health data due to long survey cycles and lack of appropriate survey instruments. Novel indicators and survey instruments would be needed to track the fast-changing situation of health emergencies.


Asunto(s)
Países en Desarrollo , Objetivos , Niño , Humanos , Renta , Desarrollo Sostenible , Organización Mundial de la Salud
5.
Ground Water ; 60(2): 295-308, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35041214

RESUMEN

Fractured rock aquifers cover much of Earth's surface and are important mountain sites for groundwater recharge but are poorly understood. To investigate groundwater systematics of a fractured-dominated aquifer in Baja California Sur, Mexico, we examined the spatial patterns of aquifer recharge and connectivity using the geochemistry of springs. We evaluate a range of geochemical data within the context of two endmember hypotheses describing spatial recharge patterns and fracture connectivity. Hypothesis 1 is that the aquifer system is segmented, and springs are fed by local recharge. Hypothesis 2 is that the aquifer system is well connected, with dominant recharge occurring in the higher elevations. The study site is a small <15 km2 catchment. Thirty-four distinct springs and two wells were identified in the study area, and 24 of these sites were sampled for geochemical analyses along an elevation gradient and canyon transect. These analyses included major ion composition, trace element and strontium isotopes, δ18 O and δ2 H isotopes, radiocarbon, and tritium. δ18 O and δ2 H isotopes suggest that the precipitation feeding the groundwater system has at least two distinct sources. Carbon isotopes showed a change along the canyon transect, suggesting that shorter flowpaths feed springs in the top of the transect, and longer flowpaths discharge near the bottom. Geochemical interpretations support a combination of the two proposed hypotheses. Understanding of the connectivity and provenance of these springs is significant as they are the primary source of water for the communities that inhabit this region and may be impacted by changes in recharge and use.


Asunto(s)
Agua Subterránea , Isótopos de Carbono/análisis , Monitoreo del Ambiente , Agua Subterránea/química , México , Pozos de Agua
7.
Tech Shoulder Elb Surg ; 19(2): 67-74, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29861663

RESUMEN

Because humeral head offset values vary widely from patient to patient, the final position of the proximal portion of a stemmed humeral prosthesis will sometimes not align well with respect to the center of rotation of the humeral head. This is especially notable when a humeral component with limited modularity is used. To address this problem, a prosthesis-specific method is presented for orienting a reverse shoulder humeral component (AltiVate Reverse, DJO Surgical, Austin, TX). With the metaphyseal-centering technique, priority is given to the positioning of the shell portion of the prosthesis over that of the stemmed portion during bone preparation. To ensure that a centralized shell position is achieved within the proximal humerus bone in patients with extreme posterior and medial offset measurement values, the stem portion of the humeral prosthesis is sometimes purposely undersized and positioned eccentrically within the humeral diaphysis. Bone autograft is used in such cases to improve the fit and fixation of the stem within the humeral canal. The metaphyseal-centering technique facilitates: (1) consistent positioning of the shell portion of the humeral prosthesis relative to the center of rotation of the humeral head, and (2) conversion from a standard to a reverse prosthesis, or vice versa, during revision surgery without the need for stem removal or alteration of the humerus bone. Preliminary outcomes of this surgical technique are encouraging, but formal studies are warranted to validate its clinical utility and longevity of results.

8.
J Shoulder Elbow Surg ; 27(6S): S50-S57, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29776472

RESUMEN

BACKGROUND: The aim of this study was to quantify the influence of prosthetic humeral head shape, as well as the number of available prosthetic head sizes, on replicating the normal humeral head anatomy during shoulder reconstructive surgery. METHODS: Computer modeling software was used to create virtual sets of both spherical and elliptical prosthetic heads, which were virtually implanted into 3-dimensional computed tomography scan-based models of 79 proximal humeri. Anatomic replication was considered successful if the measured parameters (diameters of the base of the head in the frontal and sagittal planes, radii of curvature in the frontal and sagittal planes, and humeral head height) were all reproduced within 3 mm. The Fisher exact test was used to compare the percentage of successful replications for both head types and to compare differences resulting from the use of sets with fewer or more available head sizes. Statistical significance was set at P ≤ .05. RESULTS: Regardless of the number of available head sizes per set, it was possible to replicate the normal anatomy within 3 mm in a higher percentage of specimens using elliptical (96%-100%) as opposed to spherical (41%-78%) prosthetic heads (P ≤ .0013). CONCLUSION: Compared with use of spherical prosthetic heads, use of elliptical heads resulted in improved replication of the normal humeral head shape. In light of the emerging evidence that use of anatomically shaped prosthetic humeral heads might lead to better shoulder function and possibly improved implant survivorship, the findings of this study may have important clinical and economic implications.


Asunto(s)
Artroplastía de Reemplazo de Hombro/instrumentación , Cabeza Humeral , Diseño de Prótesis , Articulación del Hombro/fisiopatología , Articulación del Hombro/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Simulación por Computador , Femenino , Humanos , Masculino , Persona de Mediana Edad , Articulación del Hombro/diagnóstico por imagen , Prótesis de Hombro , Tomografía Computarizada por Rayos X , Adulto Joven
9.
J Environ Manage ; 211: 206-217, 2018 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-29408068

RESUMEN

Septic systems (SSs) have been shown to be a significant source of nitrogen and phosphorus to nutrient-sensitive coastal surface and groundwaters. However, few published studies have quantified the effects of SSs on nutrient inputs to water supply watersheds in the Piedmont region of the USA. This region consists of rolling hills at the surface underlain by clayey soils. There are nearly 1 million SSs in this region, which accounts for approximately 50% of all SSs in North Carolina. The goal of this study was to determine if significant differences in nutrient concentrations and exports exist between Piedmont watersheds with different densities of SSs. Water quality was assessed in watersheds with SSs (n = 11) and a sewer and a forested watershed, which were designated as controls. Stream flow and environmental readings were recorded and water samples were collected from the watersheds from January 2015-December 2016. Additional samples were collected from sand filter watersheds in April 2015-March 2016 to compare to septic and control watersheds. Samples were analyzed for total dissolved nitrogen (TDN) and orthophosphate (PO4-P). Results indicated that watersheds served by a high-density (HD) of SSs (4.9 kg-N yr-1 ha-1; 0.2 kg-P yr-1 ha-1) exported more than double the median masses of TDN and PO4-P, respectively, relative to low-density (1.0 kg-N yr-1 ha-1; <0.1 kg-P yr-1 ha-1) and control watersheds (1.4 kg-N yr-1 ha-1; <0.1 kg-P yr-1 ha-1) during baseflow. Isotopic analysis indicated that wastewater was the most likely source of nitrate-N in HD watersheds. In all other watersheds, isotopic results suggested non-wastewater sources as the dominant nitrate-N provider. These findings indicated that SS density was a significant factor in the delivery of septic-derived nutrients to these nutrient-sensitive, water supply watersheds of the North Carolina Piedmont.


Asunto(s)
Nitrógeno/análisis , Contaminantes Químicos del Agua/análisis , Calidad del Agua , Monitoreo del Ambiente , North Carolina , Fósforo , Ríos , Movimientos del Agua
10.
J Shoulder Elbow Surg ; 25(9): 1532-41, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27068383

RESUMEN

BACKGROUND: The elliptical shape of the humeral head has been vaguely described, but a more detailed mathematical description is lacking. The primary goal of this study was to create formulae to describe the mathematical relationships between the various dimensions of anatomically shaped humeral heads. METHODS: Three-dimensional computer models of 79 proximal humeri derived from computed tomography scans (white subjects, 47 male and 32 female; ages, 17-87 years) were studied. Linear regression analysis of the obtained humeral measurements was performed, and Pearson correlation coefficient (R) values were calculated. To substantiate the results of the linear regression analysis, Welch t-test was used to compare various parameters of small, medium, and large humeral heads. RESULTS: Formulae for calculating humeral head height, diameters of the base of the humeral head in the frontal and sagittal planes, and radii of curvature in the frontal and sagittal planes were derived from the linear regression plots that were found to have strong (1 ≥ R ≥ 0.50) correlations. By Welch t-test, differences between the 3 head sizes were statistically significant in each case (P ≤ .022). The elliptical shape of the base of the humeral head was found to elongate with increasing humeral head size. CONCLUSIONS: Mathematical formulae relating various humeral head dimensional measurements are presented. The formulae derived in this study may be useful for the design of future prosthetic shoulder systems in which the goal is to replicate normal anatomy. This is the first study to describe that the elliptical shape of the base of the humeral head elongates as head size increases.


Asunto(s)
Simulación por Computador , Cabeza Humeral/anatomía & histología , Imagenología Tridimensional , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antropometría , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X , Adulto Joven
11.
West Indian Med J ; 63(4): 312-7, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25429467

RESUMEN

Hypertension, defined as diastolic pressure ≥ 90 mmHg and systolic pressure ≥ 140 mmHg, is a major cause of morbidity and mortality among black populations globally. Several studies have shown that prolonged consumption of cocoa or cocoa containing products leads to decreased blood pressure (BP) in hypertensives. In this study, we investigated the flavonoid content of the top selling cocoa/cocoa based products in Trinidad and Tobago and attempted to determine if consumption of cocoa had any immediate impact on blood pressure levels. The flavonoid content of three 100% cocoa powder products and four cocoa based formulas was measured using a modified Folin-Ciocalteu procedure. The brand with the highest flavonoid content, 372 gallic acid equivalents, was selected to evaluate the short-term impact of cocoa consumption on blood pressure. Thirty-six participants comprising nineteen hypertensives and seventeen persons with normal blood pressure had their blood pressure recorded on three separate days using ambulatory blood pressure monitors; the blood pressure was recorded every half hour for eight hours. On the first day, the participants received no intervention but on the second and third days, they received either the intervention (5 g cocoa in 125 ml water) or a placebo, in any order. Statistical analysis conducted using t-test statistic and a 95% confidence interval revealed that whether participants regularly took antihypertensive medication or not, a single intervention of cocoa induced decreases in both the diastolic and systolic BPs that were significant (p = 0.0001). Mean decreases of between 8 mmHg and 18 mmHg were observed.

12.
Rev Sci Instrum ; 85(8): 086109, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25173334

RESUMEN

A novel titanium reaction cell has been constructed for the study of water-rock-CO2 reactions. The reaction cell has been used within a direct-sampling rocking autoclave and offers certain advantages over traditional "flexible gold/titanium cell" approaches. The main advantage is robustness, as flexible cells are prone to rupture on depressurisation during gas-rich experiments. The reaction cell was tested in experiments during an inter-laboratory comparison study, in which mineral kinetic data were determined. The cell performed well during experiments up to 130 °C and 300 bars pressure. The data obtained were similar to those of other laboratories participating in the study, and also to previously published data.

13.
Diabet Med ; 31(6): 733-8, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24495236

RESUMEN

AIMS: To explore the impact of education and target-setting on the life stories of patients with diabetes up to 10 years after they had participated in the Dose Adjustment for Normal Eating programme (DAFNE). METHODS: Qualitative, semi-structured interviews were conducted before and after DAFNE courses to elicit narrative accounts from participants at three UK education centres. Observations of courses also took place. Data were gathered from 21 participants over 32 interviews and 146 h of observations, and analysed using a narrative approach. RESULTS: Findings suggest that patient education can create positive transformations in the lives of people with diabetes in ways that are not fully captured by simple quality-of-life scores. However, a review of evidence from other studies shows that DAFNE-recommended blood glucose results are in fact out of reach of even these most motivated and well-informed patients. This information was not shared with DAFNE attendees, who were expected to aim for near-normal HbA1c levels. After the course, participants sometimes perceived themselves as failing in their efforts, even when they had better than average blood glucose results. CONCLUSIONS: Specific and measurable low HbA1c targets may be desirable for reducing the risk of complications in diabetes, but they are not attainable or realistic even for most DAFNE graduates. It is suggested that setting goals without information about how achievable they really are could be counterproductive in terms of supporting and maintaining patient self-efficacy long-term.


Asunto(s)
Diabetes Mellitus Tipo 1/terapia , Educación del Paciente como Asunto/métodos , Autocuidado/métodos , Diabetes Mellitus Tipo 1/sangre , Hemoglobina Glucada/metabolismo , Humanos , Autoeficacia
14.
Environ Sci Pollut Res Int ; 21(1): 118-30, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23846952

RESUMEN

Generic water quality guidelines (WQGs) are developed by countries/regions as broad scale tools to assist with the protection of aquatic ecosystems from the impacts of toxicants. However, since generic WQGs cannot adequately account for the many environmental factors that may affect toxicity at a particular site, site-specific WQGs are often needed, especially for high environmental value ecosystems. The Australian and New Zealand Guidelines for Fresh and Marine Water Quality provide comprehensive guidance on methods for refining or deriving WQGs for site-specific purposes. This paper describes three such methods for deriving site-specific WQGs, namely: (1) using local reference water quality data, (2) using biological effects data from laboratory-based toxicity testing, and (3) using biological effects data from field surveys. Two case studies related to the assessment of impacts arising from mining operations in northern Australia are used to illustrate the application of these methods. Finally, the potential of several emerging methods designed to assess thresholds of ecological change from field data for deriving site-specific WQGs is discussed. Ideally, multiple lines of evidence approaches, integrating both laboratory and field data, are recommended for deriving site-specific WQGs.


Asunto(s)
Contaminantes Químicos del Agua/análisis , Calidad del Agua/normas , Australia , Ecología , Ecosistema , Ecotoxicología , Ambiente , Monitoreo del Ambiente/métodos , Monitoreo del Ambiente/normas , Política Ambiental , Guías como Asunto , Nueva Zelanda , Pruebas de Toxicidad/métodos , Pruebas de Toxicidad/normas , Contaminantes Químicos del Agua/normas , Contaminantes Químicos del Agua/toxicidad
15.
J Environ Qual ; 43(6): 1873-85, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25602204

RESUMEN

On-site wastewater treatment systems (OWTS) can contribute nitrogen (N) to coastal waters. In coastal areas with shallow groundwater, OWTS are likely affected by meteorological events. However, the meteorological influences on temporal variability of N exports from OWTS are not well documented. Hydrogeological characterization and seasonal monitoring of wastewater and groundwater quality were conducted at a residence adjacent to the Pamlico River Estuary, North Carolina, during a 2-yr field study (October 2009-2011). Rainfall was elevated during the first study year, relative to the annual mean. In the second year, drought was followed by extreme precipitation from Hurricane Irene. Recent meteorological conditions influenced N speciation and concentrations in groundwater. Groundwater total dissolved nitrogen (TDN) beneath the OWTS drainfield was dominated by nitrate during the drought; during wetter periods, ammonium and organic N were common. Effective precipitation (precipitation [P] minus evapotranspiration [ET]) affected OWTS TDN exports because of its influence on groundwater recharge and discharge. Groundwater nitrate-N concentrations beneath the drainfield were typically higher than 10 mg/L when total biweekly precipitation was less than evapotranspiration (precipitation deficit: P < ET). Overall, groundwater TDN concentrations were elevated above background concentrations at distances >15 m downgradient of the drainfield. Although OWTS nitrate inputs caused elevated groundwater nitrate concentrations between the drainfield and the estuary, the majority of nitrate was attenuated via denitrification between the OWTS and 48 m to the estuary. However, DON originating from the OWTS was mobile and contributed to elevated TDN concentrations along the groundwater flowpath to the estuary.

16.
Environ Microbiol Rep ; 5(2): 243-51, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23584968

RESUMEN

Microorganisms form symbiotic partnerships with a diverse range of marine organisms and can be critical to the health and survival of their hosts. Despite the importance of these relationships, the sensitivity of symbiotic microbes to ocean acidification (OA) is largely unknown and this needs to be redressed to adequately predict marine ecosystem resilience in a changing climate. We adopted a profiling approach to explore the sensitivity of microbes associated with coral reef biofilms and representatives of three ecologically important calcifying invertebrate phyla [corals, foraminifera and crustose coralline algae (CCA)] to OA. The experimental design for this study comprised four pHs consistent with current IPCC predictions for the next few centuries (pHNIST 8.1, 7.9, 7.7, 7.5); these pH/pCO2 conditions were produced in flow-through aquaria using CO2 bubbling. All reduced pH/increased pCO2 treatments caused clear differences in the microbial communities associated with coral, foraminifera, CCA and reef biofilms over 6 weeks, while no visible signs of host stress were detected over this period. The microbial communities of coral, foraminifera, CCA and biofilms were significantly different between pH 8.1 (pCO2 = 464 µatm) and pH 7.9 (pCO2 = 822 µatm), a concentration likely to be exceeded by the end of the present century. This trend continued at lower pHs/higher pCO2. 16S rRNA gene sequencing revealed variable and species-specific changes in the microbial communities with no microbial taxa consistently present or absent from specific pH treatments. The high sensitivity of coral, foraminifera, CCA and biofilm microbes to OA conditions projected to occur by 2100 is a concern for reef ecosystems and highlights the need for urgent research to assess the implications of microbial shifts for host health and coral reef processes.


Asunto(s)
Antozoos/microbiología , Bacterias/clasificación , Bacterias/aislamiento & purificación , Foraminíferos/microbiología , Agua de Mar/microbiología , Animales , Antozoos/fisiología , Bacterias/genética , Fenómenos Fisiológicos Bacterianos , Arrecifes de Coral , Ecosistema , Foraminíferos/fisiología , Concentración de Iones de Hidrógeno , Datos de Secuencia Molecular , Océanos y Mares , Filogenia , Agua de Mar/química , Simbiosis
17.
J Environ Health ; 76(5): 16-22, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24437045

RESUMEN

The objective of the study described in this article was to evaluate the nitrogen contributions from two onsite wastewater systems (sites 1 and 2) to groundwater and adjacent surface waters in coastal Beaufort County, North Carolina. Groundwater levels and water quality parameters including total nitrogen, nitrogen species, temperature, and pH were monitored from October 2009 to May 2010. Nitrogen was also tested in groundwater from deeper irrigation or drinking water wells from the two sites and six additional neighboring residences. Mean total nitrogen concentrations in groundwater beneath onsite wastewater systems 1 and 2 were 34.3 +/- 16.7 mg/L and 12.2 +/- 2.9 mg/L, respectively, and significantly higher than background groundwater concentrations (< 1 mg/L). Groundwater in the deeper wells appeared not to be influenced by the onsite systems. Groundwater nitrogen concentrations typically decreased with distance down-gradient from the systems, but were still elevated relative to background conditions more than 15 m from the systems and near the estuary. This was a pioneering effort to better understand the link of onsite systems, the fate of nitrogen in the environment, and public health.


Asunto(s)
Agua Subterránea/análisis , Nitrógeno/análisis , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , North Carolina
18.
Environ Toxicol Chem ; 31(11): 2606-14, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22893585

RESUMEN

The present study reanalyzed 46 existing uranium (U) chronic toxicity datasets for four freshwater species to generate consistent toxicity measures and explore relationships between U toxicity and key physicochemical variables. Dissolved organic carbon (DOC) was consistently the best predictor of U toxicity based on 10% inhibitory concentration (IC10) and median inhibitory concentration (IC50) values, with water hardness also being a significant co-predictor of IC50 concentrations for one species. The influence of DOC on acute and chronic U toxicity was further characterized using existing data for five species, and was found to vary depending on species, DOC source, and exposure duration (acute vs chronic). The slopes of the relationships between DOC and (normalized) acute and chronic U toxicity were modeled using cumulative probability distributions. From these, slopes were selected for which to correct acute or chronic U toxicity values or hazard estimates based on the aquatic DOC concentration. The fifth percentiles of these cumulative probability distributions for acute and chronic exposure data were 0.064 and 0.090, respectively, corresponding to a 6.4 and 9.0% reduction in U toxicity relative to the toxicity at the base DOC concentration for each 1 mg/L increase in DOC concentration (over the DOC range 0-30 mg/L). Algorithms were developed to enable the adjustment of U toxicity values and U hazard estimates, depending on DOC concentrations. These algorithms will significantly enhance the environmental relevance of water quality/risk assessments for U in fresh surface waters.


Asunto(s)
Organismos Acuáticos/efectos de los fármacos , Carbono/química , Uranio/toxicidad , Contaminantes Radiactivos del Agua/toxicidad , Algoritmos , Animales , Chlorella/efectos de los fármacos , Cladóceros/efectos de los fármacos , Ecotoxicología/métodos , Hydra/efectos de los fármacos , Concentración 50 Inhibidora , Modelos Lineales , Pruebas de Toxicidad Aguda , Pruebas de Toxicidad Crónica
19.
Water Sci Technol ; 63(4): 789-95, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21330729

RESUMEN

The study goal was to determine if on-site wastewater systems (OSWWS) installed in coastal areas were effective at reducing indicator bacteria densities before discharge to groundwater. Groundwater Escherichia coli (E. coli) densities and groundwater levels adjacent to 16 OSWWS in three different soil groups (sand, sandy loam, and sandy clay loam) were monitored and compared to background groundwater conditions on four occasions between March 2007 and February 2008 in coastal North Carolina. Groundwater beneath OSWWS had significantly (p≤0.05) lower densities of E. coli than septic tank effluent, but significantly higher densities of E. coli than background conditions for each soil type. Twenty three percent of all groundwater samples near OSWWS had E. coli densities that exceeded the EPA freshwater contact standards (single sample 235 cfu/100 mL) for surface waters. Groundwater E. coli densities near OSWWS were highest during shallow water table periods. The results indicate that increasing the required vertical separation distance from drainfield trenches to seasonal high water table could improve shallow groundwater quality.


Asunto(s)
Escherichia coli/metabolismo , Eliminación de Residuos Líquidos/métodos , Microbiología del Agua , Agua/química , Biodegradación Ambiental , North Carolina , Microbiología del Suelo
20.
Clin Microbiol Infect ; 17(2): 244-7, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20491826

RESUMEN

Group C rotavirus (GpC RV) causes sporadic cases and outbreaks of acute diarrhoea in humans worldwide, but has not been detected among children in South Korea. The present study aimed to detect GpC RV among children hospitalized with gastroenteritis in South Korea and to perform a molecular characterization of GpC RV strains. From November 2003 to January 2006, 434 faecal samples were collected from children <10 years of age who were hospitalized for treatment of acute diarrhoea and screened for group C and A rotaviruses by enzyme immunoassay. GpC RV strains were characterized by sequence and phylogenetic analysis.Of the 434 samples screened, two were positive for GpC RV and one had a mixed GpC and GpA RV infection. One of the strains, Icheon, shared high sequence conservation in VP4, VP6 and VP7 genes with other published GpC RV. This is the first report describing the molecular characteristics of GpC RV among children in South Korea. Additional surveillance is needed to determine the burden of GpC RV gastroenteritis.


Asunto(s)
Gastroenteritis/virología , Infecciones por Rotavirus/diagnóstico , Infecciones por Rotavirus/virología , Rotavirus/clasificación , Rotavirus/aislamiento & purificación , Niño , Preescolar , Heces/virología , Genotipo , Hospitalización , Humanos , Lactante , Datos de Secuencia Molecular , Filogenia , ARN Viral/genética , República de Corea , Rotavirus/genética , Análisis de Secuencia de ADN
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