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1.
Physiother Can ; 76(1): 46-54, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38465311

RESUMO

Purpose: This qualitative descriptive study researched educators' perspectives of type 2 diabetes (T2D) Teaching and learning, in physiotherapy (PT) programmes across Canada. Methods: Faculty members and clinical instructors from the 15 PT programmes in Canada were contacted. Online surveys collected data on the educators' professional background and perspectives on T2D in the PT curriculum. One-on-one telephone interviews were conducted and thematic analysis was used to generate themes and codes from the interview transcripts. Results: Ten educators from 10 universities completed the survey. Seven of the 10 educators also participated in a telephone interview. Survey responses revealed that T2D content is taught predominantly through case studies and lectures. Of the 10 respondents, six reported that the curriculum does not devote adequate time to T2D content, and nine reported they "strongly agree" or "agree" that T2D is an essential component of the PT curriculum. The interviews revealed that T2D content varies across PT programmes. The educators agreed that T2D is a common condition seen in practice, there is a role for PT intervention, and T2D content is limited by classroom time. Conclusions: Educators noted challenges integrating more T2D content in the curriculum and said that PT clinical contributions for people living with T2D are underutilized. Additional evidence-informed rationale is needed to explore optimal integration of T2D content in PT programmes.


Objectif: étude descriptive qualitative sur le point de vue des éducateurs à l'égard de l'enseignement et de l'apprentissage sur le diabète de type 2 (DT2) dans les programmes de physiothérapie du Canada. Méthodologie: prise de contact avec les professeurs et éducateurs cliniques de 15 programmes de physiothérapie au Canada. Au moyen de sondages en ligne, les chercheurs ont recueilli des données sur l'expérience professionnelle des éducateurs et leurs points de vue au sujet du DT2 dans le programme de physiothérapie. Ils ont réalisé des entrevues individuelles et procédé à une analyse thématique pour dégager des thèmes et des codes à partir des transcriptions d'entrevue. Résultats: dix éducateurs de dix universités ont rempli le sondage. Sept d'entre eux ont également participé à une entrevue téléphonique. Les réponses au sondage ont révélé que la matière sur le DT2 est surtout enseignée dans le cadre d'études de cas et d'exposés.Six des dix répondants ont déclaré que le programme ne prévoit pas assez de temps sur la matière liée au DT2 et neuf ont affirmé qu'ils étaient « fortement d'accord ¼ ou « d'accord ¼ avec le fait que le DT2 est un élément essentiel du programme de physiothérapie. Les entrevues ont révélé que la matière sur le DT2 varie selon les programmes. Les éducateurs ont convenu que le DT2 est une affection courante en pratique, qu'il y a un rôle pour une intervention en physiothérapie et que la matière sur le DT2 est limitée par le temps en classe. Conclusions: les éducateurs ont souligné les difficultés à intégrer plus de matière sur le DT2 au programme et ont affirmé que l'apport clinique est sous-utilisé en physiothérapie auprès des personnes qui vivent avec le DT2. Il faudra obtenir plus d'explications fondées sur des données probantes pour explorer la manière optimale d'intégrer de la matière sur le DT2 aux programmes de physiothérapie.

2.
Pharm Stat ; 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38351464

RESUMO

Immunoassays play an important role in drug development of products targeting the immune system. Consistent quality of the results from an immunoassay is essential to make unbiased and accurate claims about the drug product during preclinical and clinical development stages. Assay qualification and validation shed light on the performance of the assay. It is the first evaluation and the verification, respectively, of the assay's performance. This tutorial explains and illustrates the calculation methodology for important assay qualification parameters including precision, relative accuracy, linearity, the lower limit of quantification (LLOQ), the upper limit of quantification (ULOQ), the assay range and dilutability. This tutorial focuses on assays used for (pre-) clinical purposes, characterized by a lognormal distribution of the measurements on its original untransformed scale and by the lack of well characterized reference material. Statistical calculations are illustrated with qualification data from an enzyme-linked immunosorbent assay (ELISA) vaccine immunoassay.

3.
NPJ Vaccines ; 9(1): 8, 2024 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-38184641

RESUMO

The quantitation of antibody responses is a critical requirement for the successful development of vaccines and therapeutics that often relies on the use of standardized reference materials to determine relative quantities within biological samples. The validity of comparing responses across assays using arbitrarily defined reference values is therefore limited. We developed a generalizable method known as MASCALE (Mass Spectrometry Enabled Conversion to Absolute Levels of ELISA Antibodies) for absolute quantitation of antibodies by calibrating ELISA reference sera using mass spectrometry. Levels of proteotypic peptides served as a proxy for human IgG, allowing the conversion of responses from arbitrary values to absolute amounts. Applications include comparison of binding assays at two separate laboratories and evaluation of cross-clade magnitude-breadth responses induced by an investigational HIV-1 vaccine regimen. MASCALE addresses current challenges in the interpretation of immune responses in clinical trials and expands current options available to make suitable comparisons across different settings.

5.
ACS Earth Space Chem ; 7(12): 2382-2392, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38148993

RESUMO

Isotope fractionation related to photochemical reactions and planktonic uptake at the base of the food web is a major uncertainty in the biological application of mercury (Hg) stable isotopes. In freshwater systems, it is unclear how competitive interactions among methylmercury (MeHg), dissolved organic matter (DOM), and phytoplankton govern the magnitude of mass-dependent and mass-independent fractionation. This study investigated how DOM alters rates of planktonic MeHg uptake and photodegradation and corresponding Hg isotope fractionation in the presence of freshwater phytoplankton species, Raphidocelis subcapitata. Outdoor sunlight exposure experiments utilizing R. subcapitata were performed in the presence of different DOM samples using environmentally relevant ratios of MeHg-DOM thiol groups. The extent of Δ199Hg in phytoplankton incubations (2.99‰ St. Louis River HPOA, 1.88‰ Lake Erie HPOA) was lower compared to paired abiotic control experiments (4.29 and 2.86‰, respectively) after ∼30 h of irradiation, resulting from cell shading or other limiting factors reducing the extent of photodemethylation. Although the Δ199Hg/Δ201Hg ratio was uniform across experiments (∼1.4), Δ199Hg/δ202Hg slopes varied dramatically (from -0.96 to 15.4) across incubations with R. subcapitata and DOM. In addition, no evidence of Hg isotope fractionation was observed within R. subcapitata cells. This study provides a refined examination of Hg isotope fractionation markers for key processes occurring in the lower food web prior to bioaccumulation, critical for accurately accounting for the photochemical processing of Hg isotopes across a wide spectrum of freshwater systems.

6.
Nurse Educ Pract ; 73: 103833, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37952474

RESUMO

AIM: The aim of this scoping review is to summarize and critically evaluate research focused on nursing bridging education programs internationally. Specifically, this review addresses bridging from a: (1) Personal Support Worker (or similar) to a Registered Practical Nurse (or similar); and (2) Registered Practical Nurse (or similar) to a Registered Nurse. BACKGROUND: Nursing bridging education programs support learners to move from one level of educational preparation or practice to another. These programs can therefore increase nursing workforce capacity. Global healthcare systems have faced nursing shortages for decades. Moreover, the presently insufficient nursing workforce is confronting an ever-increasing volume of needed healthcare that is rising with the global ageing demographic shift. DESIGN: The Joanna Briggs Institute methods for scoping reviews, combined with Arksey and O'Malley's (2005) guidelines, were used with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR). METHODS: MEDLINE (Ovid), CINAHL, EMBASE and SCOPUS databases were searched. Articles published in English that included Personal Support Workers, Registered Practical Nurses, Registered Nurses and/or nurses in similar categories who were studied through the process of a nursing bridging education program were included in the review. The study search was limited to papers published after 2005 (i.e., the beginning of nurse workload "overload" according to the Canadian Nurses Association). Braun and Clarke's (2006) thematic analysis was used in a content analysis of the included studies. RESULTS: A total of 15 articles published between 2005 and 2022 were included. Four themes were generated: (1) participating in bridging education programs fuels both professional and personal development; (2) nursing bridging education programs enhance diversity in the nursing workforce; (3) student nurses do not anticipate the challenges associated with participating in a bridging program; and (4) mentor-mentee connection promotes academic learning and successful completion of nursing bridging education programs. CONCLUSIONS: Despite experiencing challenges, participation in/completion of nursing bridging education programs leads to successful role transitioning and self-reported fulfillment of personal and professional aspirations. This review revealed the need for bridging programs to accommodate the unique needs of student nurses. Incorporation of support services, mentorship and faculty familiarity with varying nursing educational backgrounds facilitates role transitions by reducing the perceived challenges of bridging and promoting connection to foster learning. Nursing bridging education programs allow greater numbers of nurses to be trained to build workforce capacity and enable care for the world's rapidly ageing population.


Assuntos
Educação em Enfermagem , Recursos Humanos de Enfermagem , Humanos , Canadá , Aprendizagem , Atenção à Saúde
7.
Environ Sci Technol Lett ; 10(10): 891-896, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37840816

RESUMO

The transfer of aquatic contaminants, including mercury (Hg), to terrestrial food webs is an often-overlooked exposure pathway to terrestrial animals. While research has implemented the use of shoreline spiders to assess aquatic to terrestrial Hg transfer, it is unclear whether Hg sources, estimated from isotope ratios, can be successfully resolved to inform site assessments and remedy effectiveness. To examine aquatic to terrestrial Hg transfer, we collected shoreline spiders (Tetragnatha spp.) and aquatic insect larvae (suborder Anisoptera) across a mosaic of aquatic and shoreline habitats in the St. Louis River and Bad River, tributaries to Lake Superior. The fraction of industrial Hg in sediments was reflected in the δ202Hg values of aquatic dragonfly larvae and predatory fish, connecting benthic Hg sources to the aquatic food web. Shoreline spiders mirrored these aquatic Hg source signatures with highly positive correlations in δ202Hg between tetragnathids and dragonfly larvae (r2 = 0.90). Further assessment of different spider taxa (i.e., araneids and pisaurids) revealed that differences in prey consumption and foraging strategies resulted in isotope differences, highlighting the importance of spider taxa selection for Hg monitoring efforts.

8.
Environ Pollut ; 336: 122447, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37648055

RESUMO

In Suriname, mercury (Hg) use has recently increased because of gold mining, which has put fish-reliant communities (e.g., Indigenous and Tribal) at risk of enhanced Hg exposure through the riverine fish these communities consume. To quantify how the magnitude of these risks change according to location and time, we measured total mercury (HgT) in fish at sites downstream and upstream of an artisanal and small-scale gold mining (ASGM) operation in 2004-2005 and in 2017-2018. We tested whether fish HgT burdens over dynamic ranges were increased. Surprisingly, our findings did not support broadly increased fish Hg burden over time or that proximity to ASGM was diagnostic to fish HgT-burden. Subsequently, we elected to test the HgT stable isotope ratios on a set of freshly collected 2020 fish to determine whether differences in Hg source and delivery pathways might cofound results. We found that remote unmined sites were more susceptible to gaseous elemental Hg deposition pathways, leading to enhanced risk of contamination, whereas ASGM proximate sites were not. These results highlight that elemental mercury releases from ASGM practices may have significant impact on fish-reliant communities that are far removed from ASGM point source contamination.


Assuntos
Mercúrio , Animais , Mercúrio/análise , Exposição Ambiental/análise , Suriname , América do Sul , Ouro , Peixes/metabolismo , Monitoramento Ambiental
9.
J Geophys Res Atmos ; 128(8): 1-15, 2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37593527

RESUMO

With the 2011 promulgation of the Mercury and Air Toxics Standards by the U.S. Environmental Protection Agency, and the successful negotiation by the United Nations Environment Program of the Minamata Convention, emissions of mercury (Hg) have declined in the United States. While the declines in atmospheric Hg concentrations in North America are encouraging, linking the declines to changing domestic and global source portfolios remains challenging. To address these research gaps, the U.S. Geological Survey initiated the first national-scale effort to establish a baseline of total gaseous mercury stable isotope values at 31 sites distributed across the United States. Results indicated that unique Hg sources, such as Hg evasion from an elemental Hg contaminated site or free tropospheric intrusions in high altitude sites, were distinguishable from background atmospheric values. Minor gradients were observed across the nation, with regions of heavy industrial activity demonstrating lower δ202Hg, but no consistent changes in other isotopes such as Δ199Hg and Δ200Hg were observed. Furthermore, δ202Hg was impacted by foliar uptake and senescence but trends varied between forested regions in the northeastern and midwestern United States. These data demonstrate regional emission sources and other environmental variables can impact total gaseous Hg (TGM) isotope values, highlighting the need to characterize atmospheric Hg isotopes over larger geographical areas to evaluate changes related to national and international Hg regulations.

10.
Front Environ Chem ; 4: 1096199, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37323923

RESUMO

Ecosystems downstream of mercury (Hg) contaminated sites can be impacted by both localized releases as well as Hg deposited to the watershed from atmospheric transport. Identifying the source of Hg in water, sediment, and fish downstream of contaminated sites is important for determining the effectiveness of source-control remediation actions. This study uses measurements of Hg stable isotopes in soil, sediment, water, and fish to differentiate between Hg from an abandoned Hg mine from non-mine-related sources. The study site is located within the Willamette River watershed (Oregon, United States), which includes free-flowing river segments and a reservoir downstream of the mine. The concentrations of total-Hg (THg) in the reservoir fish were 4-fold higher than those further downstream (>90 km) from the mine site in free-flowing sections of the river. Mercury stable isotope fractionation analysis showed that the mine tailings (δ202Hg: -0.36‰ ± 0.03‰) had a distinctive isotopic composition compared to background soils (δ202Hg: -2.30‰ ± 0.25‰). Similar differences in isotopic composition were observed between stream water that flowed through the tailings (particulate bound δ202Hg: -0.58‰; dissolved: -0.91‰) versus a background stream (particle-bound δ202Hg: -2.36‰; dissolved: -2.09‰). Within the reservoir sediment, the Hg isotopic composition indicated that the proportion of the Hg related to mine-release increased with THg concentrations. However, in the fish samples the opposite trend was observed-the degree of mine-related Hg was lower in fish with the higher THg concentrations. While sediment concentrations clearly show the influence of the mine, the relationship in fish is more complicated due to differences in methylmercury (MeHg) formation and the foraging behavior of different fish species. The fish tissue δ13C and Δ199Hg values indicate that there is a higher influence of mine-sourced Hg in fish feeding in a more sediment-based food web and less so in planktonic and littoral-based food webs. Identifying the relative proportion of Hg from local contaminated site can help inform remediation decisions, especially when the relationship between total Hg concentrations and sources do not show similar covariation between abiotic and biotic media.

11.
Graefes Arch Clin Exp Ophthalmol ; 261(7): 1987-1994, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36802230

RESUMO

PURPOSE: To evaluate the safety and efficacy of 360° circumferential trabeculotomy (TO) for steroid induced glaucoma (SIG) of short duration. METHODS: Retrospective analysis of surgical results of 46 eyes of 35 patients undergoing microcatheter-assisted TO. All eyes had high intraocular pressure for at most about 3 years due to steroid use. Follow-up was between 2.63 and 47.9 months (mean 23.9, median 25.6). RESULTS: Intraocular pressure (IOP) before surgery was 30.8 ± 8.3 mm Hg, with 3.8 ± 1.0 pressure-lowering medications. After 1 to 2 years, mean IOP was 11.2 ± 2.6 mm Hg (n = 28); mean number of IOP-lowering medications was 0.9 ± 1.3. At their last follow-up, 45 eyes had an IOP < 21 mm Hg, and 39 eyes had an IOP < 18 mm Hg with or without medication. After 2 years, the estimated probability of having an IOP below 18 mm Hg (with or without medication) was 85 ± 6%, and the estimated probability of not using medication was 56 ± 7%. Steroid response was no longer present in all eyes receiving steroids after surgery. Minor complications consisted of hyphema, transient hypotony, or hypertony. One eye proceeded to receiving a glaucoma drainage implant. CONCLUSION: TO is particularly effective in SIG with relative short duration. This concurs with the pathophysiology of the outflow system. This procedure seems particularly suited for eyes for which target pressures in the mid-teens are acceptable, particularly when chronic use of steroids is necessary .


Assuntos
Glaucoma , Trabeculectomia , Adolescente , Humanos , Adulto , Trabeculectomia/métodos , Estudos Retrospectivos , Malha Trabecular/cirurgia , Resultado do Tratamento , Glaucoma/induzido quimicamente , Glaucoma/cirurgia , Pressão Intraocular , Seguimentos
12.
Physiother Theory Pract ; 39(12): 2662-2675, 2023 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-35794692

RESUMO

BACKGROUND: Exercise programs for adults with type 2 diabetes (T2D) improve glycemic control and physical function. However, diabetes complications, disability, and motivation pose challenges for exercise participation. OBJECTIVE: The purpose of the study was to: 1) measure change in fasting blood glucose, blood pressure, anthropometrics (i.e. BMI and waist circumference), and physical function (i.e. endurance, agility and balance, upper and lower-body strength and flexibility) after completing an eight-week education and exercise program for adults with T2D; and 2) explore the experience of exercise continuation in people living with T2D at one-year follow-up. METHODS: A mixed methods case series design was conducted. Participants were ≥ 18 years and had a clinical diagnosis of T2D (glycated hemoglobin (A1C) ≥ 6.5%). Participants completed two one-hour exercise sessions and one one-hour education session per week for eight weeks. Blood glucose, blood pressure, body mass index (BMI), waist circumference, and physical function were measured at baseline and after completing the program. Follow-up telephone interviews were conducted at one, six, and 12-months and thematic analysis was employed to analyze interviews. RESULTS: Twelve participants completed the program. Clinically significant improvements were observed for waist circumference, systolic blood pressure, six-minute walk test (6MWT), timed up-and-go test (TUG), 30-second chair stand test (CST) and arm curls. Three themes emerged from the interviews that described participant reflections and experiences with a supervised education and exercise program for management of their T2D: 1) medical management; 2) lifestyle management; and 3) finding what works. Conclusion: Supervised programming improves physical function and may mitigate disability. Physiotherapists are qualified to assess and treat physical function through education and exercise.


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Adulto , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/terapia , Glicemia , Motivação , Exercício Físico/fisiologia , Terapia por Exercício/métodos
14.
Environ Sci Technol Lett ; 10(2): 165-171, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38357329

RESUMO

To evaluate the utility of preserved fishes for reconstructing historical and spatial patterns of mercury (Hg) exposure, we experimentally tested the stability of Hg concentrations and Hg stable isotope ratios under standard museum practices of specimen preservation. We found that loss of unidentified constituents during preservation increased Hg concentrations in fish muscle. Low-Hg fish reared in the laboratory were susceptible to exogenous contamination with inorganic mercury (iHg) when preservative fluids were intentionally spiked or iHg leached passively from contaminated wild fishes in the same container. This contamination impacted Hg isotope values of total Hg, but the conservative nature of methylmercury allows us to quantitatively correct for iHg contamination. Our findings validate the potential to use fishes from the world's museums to generate spatiotemporal baselines for the Minamata Convention on Mercury, but we recommend a set of precautions to maximize inference strength. Selecting the largest specimens of a target species helps dilute any iHg contamination. Specimens should be drawn from lots that were not comingled with fishes from other collections to minimize risk of iHg transfer among fish with different contamination histories. Finally, focusing on low-lipid species will enhance the comparability of Hg concentrations between historical and contemporary collections.

15.
Environ Sci Process Impacts ; 24(10): 1805-1820, 2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36065894

RESUMO

Mercury (Hg) deposition was reconstructed in sediment cores from lakes in two coastal U.S. National Parks: Acadia National Park (ANP) and Cape Cod National Seashore (CCNS), to fill an important spatial gap in Hg deposition records and to explore changing sources of Hg and processes affecting Hg accumulation in these coastal sites. Recent Hg deposition chronology was assessed using (1) a newly developed lead-210 (210Pb) based sediment age model which employs 7Be to constrain deposition and sediment mixing of 210Pb-excess, (2) coinciding Pb flux and isotope ratios (206Pb/207Pb), and (3) Hg isotope ratios and their response to changes in Hg flux. At both sites, Hg flux increased substantially from pre-1850 levels, with accumulation in ANP peaking in the 1970s, whereas in CCNS, Hg levels were highest in recent sediments. Negative values of δ202Hg and Δ199Hg indicated terrestrially-derived Hg was a major constituent of Hg flux to Sargent Mountain Pond, ANP, although recent decreases in Hg flux were in agreement with precipitation Hg records, indicating a rapid watershed response. By contrast, δ202Hg and Δ199Hg profiles in Long Pond, CNNS reflect direct Hg deposition, but disturbances in the sedimentary record were indicated by bomb fallout radionuclide inventories and by peaks in both Pb and Hg isotope depth profiles. These cores provided poor reconstructions of atmospheric deposition and reveal responses that are decoupled from emissions reduction due to complex post-depositional redistribution of atmospheric metals including Hg. The application of multiple tracers of Hg deposition provide insight into the sources and pathways governing Hg accumulation in these lakes.


Assuntos
Mercúrio , Poluentes Químicos da Água , Monitoramento Ambiental , Sedimentos Geológicos , Lagos , Chumbo , Mercúrio/análise , Poluentes Químicos da Água/análise
16.
Environ Toxicol Chem ; 41(11): 2732-2744, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35975428

RESUMO

We examined how dietary factors recorded by C and N influence Hg uptake in 347 individuals of yellowfin tuna (Thunnus albacares), an important subsistence resource from the Galápagos Marine Reserve (Ecuador) and the Ecuadorian mainland coast in 2015-2016. We found no differences in total Hg (THg) measured in red muscle between the two regions and no seasonal differences, likely due to the age of the fish and slow elimination rates of Hg. Our THg concentrations are comparable to those of other studies in the Pacific (0.20-9.60 mg/kg wet wt), but a subset of individuals exhibited the highest Hg concentrations yet reported in yellowfin tuna. Mercury isotope values differed between Δ199 Hg and δ202Hg in both regions (Δ199 Hg = 2.86 ± 0.04‰ vs. Δ199 Hg = 2.33 ± 0.07‰), likely related to shifting food webs and differing photochemical processing of Hg prior to entry into the food web. There were significantly lower values of both δ15 N and δ13 C in tuna from Galápagos Marine Reserve (δ15 N: 8.5-14.2‰, δ13 C: -18.5 to -16.1‰) compared with those from the Ecuadorian mainland coast (δ15 N: 8.3-14.4‰, δ13 C: -19.4 to -11.9‰), of which δ13 C values suggest spatially constrained movements of tuna. Results from the pooled analysis, without considering region, indicated that variations in δ13 C and δ15 N values tracked changes of Hg stable isotopes. Our data indicate that the individual tuna we used were resident fish of each region and were heavily influenced by upwellings related to the eastern Pacific oxygen minimum zone and the Humboldt Current System. The isotopes C, N, and Hg reflect foraging behavior mainly on epipelagic prey in shallow waters and that food web shifts drive Hg variations between these populations of tuna. Environ Toxicol Chem 2022;41:2732-2744. © 2022 SETAC.


Assuntos
Mercúrio , Animais , Mercúrio/análise , Atum , Equador , Isótopos de Mercúrio/análise , Isótopos/análise , Oxigênio/análise
17.
Environ Sci Technol Lett ; 9(4): 312-319, 2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35685226

RESUMO

Lake trout (Salvelinus namaycush), collected from 13 remote lakes located in southwestern Alaska, were analyzed for carbon, nitrogen, and mercury (Hg) stable isotope values to assess the importance of migrating oceanic salmon, volcanic activity, and atmospheric deposition to fish Hg burden. Methylmercury (MeHg) bioaccumulation in phytoplankton (5.0 - 6.9 kg L-1) was also measured to quantify the basal uptake of MeHg to these aquatic food webs. Hg isotope values in lake trout revealed that while the extent of precipitation-delivered Hg was similar across the entire study area, volcanic Hg is likely an important additional source to lake trout in proximate lakes. In contrast, migratory salmon (Oncorhynchus nerka) deliver little MeHg to lake trout directly, although indirect delivery processes via decay could exist. A high level of variability in carbon, nitrogen, and Hg isotope values indicate niche partitioning in lake trout populations within each lake and that a complex suite of ecological interactions is occurring, complicating the conceptually linear assessment of contaminant source to receiving organism. Without connecting energy and contaminant isotope axes, we would not have understood why lake trout from these pristine lakes have highly variable Hg burdens despite consistently low water Hg and comparable age-length dynamics.

18.
Sci Total Environ ; 838(Pt 1): 156031, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35595135

RESUMO

Mercury (Hg) contamination has been a persistent concern in the Florida Everglades for over three decades due to elevated atmospheric deposition and the system's propensity for methylation and rapid bioaccumulation. Given declines in atmospheric Hg concentrations in the conterminous United States and efforts to mitigate nutrient release to the greater Everglades ecosystem, it was vital to assess how Hg dynamics responded on temporal and spatial scales. This study used a multimedia approach (water and biota) to examine Hg and methylmercury (MeHg) dynamics across a 76-site network within the southernmost portion of the region, Everglades National Park (ENP), from 2008 to 2018. Hg concentrations across matrices showed that air, water, and biota from the system were inextricably linked. Temporal patterns across matrices were driven primarily by hydrologic and climatic changes in the park and no evidence of a decline in atmospheric Hg deposition from 2008 to 2018 was observed, unlike other regions of the United States. In the Shark River Slough (SRS), excess dissolved organic carbon and sulfate were also consistently delivered from upgradient canals and showed no evidence of decline over the study period. Within the SRS a strong positive correlation was observed between MeHg concentrations in surface water and resident fish. Within distinct geographic regions of ENP (SRS, Marsh, Coastal), the geochemical controls on MeHg dynamics differed and highlighted regions susceptible to higher MeHg bioaccumulation, particularly in the SRS and Coastal regions. This study demonstrates the strong influence that dissolved organic carbon and sulfate loads have on spatial and temporal distributions of MeHg across ENP. Importantly, improved water quality and flow rates are two key restoration targets of the nearly 30-year Everglades restoration program, which if achieved, this study suggests would lead to reduced MeHg production and exposure.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Poluentes Químicos da Água , Animais , Bioacumulação , Ecossistema , Monitoramento Ambiental , Mercúrio/análise , Parques Recreativos , Sulfatos , Poluentes Químicos da Água/análise
19.
Orthop J Sports Med ; 10(3): 23259671221085272, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35356312

RESUMO

Background: An iatrogenic injury to the infrapatellar branch of the saphenous nerve (IPBSN) is a common precipitant of postoperative knee pain and hypoesthesia. Purpose: To locate potential safe zones for incision by observing the patterns and pathway of the IPBSN while examining the relationship of its location to sex, laterality, and leg length. Study Design: Descriptive laboratory study. Methods: A total of 107 extended knees from 55 formalin-embalmed cadaveric specimens were dissected. The nerve was measured from palpable landmarks: the patella at the medial (point A) and lateral (point B) borders of the patellar ligament, the medial border of the patellar ligament at the patellar apex (point C) and tibial plateau (point D), the medial epicondyle (point E), and the anterior border of the medial collateral ligament at the tibial plateau (point F). The safe zone was defined as 2 SDs from the mean. Results: Findings indicated significant correlations between leg length and height (r P = 0.832; P < .001) as well as between leg length and vertical measurements (≥45°) from points A and B to the IPBSN (r P range, 0.193-0.285; P range, .004-.049). Male specimens had a more inferior maximum distance from point A to the intersection of the IPBSN and the medial border of the patellar ligament compared with female specimens (6.17 vs 5.28 cm, respectively; P = .049). Right knees had a more posterior IPBSN from point F compared with left knees (-0.98 vs-0.02 cm, respectively; P = .048). The majority of knees (62.6%; n = 67) had a nerve emerging that penetrated the sartorius muscle. Additionally, 32.7% (n = 35) had redundant innervation, and 25.2% (n = 27) had contribution from the intermediate femoral cutaneous nerve (IFCN). Conclusion: We identified no safe zone. Significant innervation redundancy with a substantial contribution to the infrapatellar area from the IFCN was noted and contributed to the expansion of the danger zone. Clinical Relevance: The location of incision and placement of arthroscopic ports might not be as crucial in postoperative pain management as an appreciation of the variance in infrapatellar innervation. The IFCN is a common contributor. Its damage could explain pain refractory to SN blocks and therefore influence anesthetic and analgesic decisions.

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