2,270 research outputs found
Recommended from our members
Trace metal concentrations in the signal crayfish, Pacifastacus leniusculus (Decapoda: Astacidae), and the stonefly Pteronarcys californica (Plecoptera: Pteronarcyidae) along a downstream gradient of the Umatilla River
Metals are a persistent form of freshwater pollution and have been shown to bioaccumulate in aquatic macroinvertebrates through direct contact with contaminated water, sediments, and through consumption of contaminated organisms. This research explored the longitudinal bioaccumulation patterns of 5 common trace metals (Cr, Cu, Zn, Cd, and Pb) in the signal crayfish, Pacifastacus leniusculus, and stonefly Pteronarcys californica along the mainstem Umatilla River. The Umatilla River drains a largely agricultural basin in northeastern Oregon and spans 140 kilometers from its headwaters in the Blue Mountains to its confluence with the Columbia River near Hermiston.
Crayfish concentrations of Zn and Pb, and to a lesser degree Cr, were significantly correlated with river distance, but contrary to expectations, concentrations decreased in the downstream direction. Cu and Zn were unrelated to river distance. Concentrations of Cr, Pb, and to a lesser degree Cd, were also significantly, negatively associated with crayfish carapace length, which was used as a proxy for age. Larger, older crayfish had lower concentrations, suggesting growth dilution. ANCOVA was used to test for effects of gender and mesohabitat on crayfish metal concentration after accounting for river distance and carapace length as covariates. Male crayfish had significantly higher Zn, Cd, Pb, and Cr concentrations than females, but absolute differences were fairly small. A significant difference in crayfish Pb concentrations between mesohabitats was found, with slightly higher concentrations in runs than riffles. Crayfish Cu concentrations were not correlated with any of the morphological, physicochemical, or spatial variables measured in this study. Due to their small size, metal concentrations in stoneflies were only measured in a single composite sample at each site, and stoneflies were only found at 7 of the upstream river sample sites. As a result, this small dataset was suggestive, but not conclusive, of relationships between stonefly metal concentrations and other variables. For both crayfish and stoneflies, none of the sampled metals appeared to clearly correlate with suspected point source or potential diffuse metal inputs.
This study also examined habitat associations of P. leniusculus by life history stage. Microhabitat scale differences in collection methods were found, with nonrandom methods (kick sampling and boulder flipping) resulting in a significantly higher number of crayfish captured than the random method (kick sampling). Using PCA, an exploration of microhabitat scale characteristics associated with P. leniusculus by size group found that crayfish with carapace length >20 mm were significantly associated with deeper water, higher percentages of organic matter and riparian cover, and higher water velocity. Distinct differences in habitat association also existed among three juvenile size groups. The smallest, youngest juvenile size group (carapace length <10 mm) showed a low association with velocity, percent organic matter, and percent riparian cover; the middle juvenile size group (carapace length 10-15 mm) was negatively associated with water depth; the largest juvenile size group (carapace length 15-20 mm) was comparatively less negative in its association with water depth, and more positively associated with velocity, percent organic matter, and percent riparian cover
Recommended from our members
Ground‐nesting Yellowjackets, Vespula Spp. (Hymeoptera: Vespidae), in Oregon School Environments
Early Quadriceps Strength Loss After Total Knee Arthroplasty : The Contributions of Muscle Atrophy and Failure of Voluntary Muscle Activation
While total knee arthroplasty reduces pain and provides a functional range of motion of the knee, quadriceps weakness and reduced functional capacity typically are still present one year after surgery. The purpose of the present investigation was to determine the role of failure of voluntary muscle activation and muscle atrophy in theearly loss of quadriceps strength after surgery
Report on the May-June 2002 Englebright Lake deep coring campaign
This report describes the May-June 2002 Englebright Lake coring project. Englebright Lake is a 14-km-long reservoir on the Yuba River of northern California, impounded by Englebright Dam, which was completed in 1940. The sediments were cored to assess the current conditions in the reservoir as part of the California Bay-Delta Authority’s Upper Yuba River Studies Program. Sediment was collected using both hydraulic-piston and rotational coring equipment mounted on a floating drilling platform. Thirty boreholes were attempted at 7 sites spaced along the longitudinal axis of the reservoir. Complete sedimentary sections were recovered from 20 boreholes at 6 sites. In total, 335 m of sediment was cored, with 86% average recovery. The core sections (each up to 1.5 m long) were processed using a standard set of laboratory techniques, including geophysical logging of physical properties, splitting, visual descriptions, digital photography, and initial subsampling. This report presents the results of these analyses in a series of stratigraphic columns. Using the observed stratigraphy as a guide, several series of subsamples were collected for various sedimentologic, geochemical, and geochronological analyses. The results of laboratory analyses of most of these subsamples will be presented in future reports and articles
Early quadriceps strength loss after total knee arthroplasty
Background: While total knee arthroplasty reduces pain and provides a functional range of motion of the knee,
quadriceps weakness and reduced functional capacity typically are still present one year after surgery. The purpose of
the present investigation was to determine the role of failure of voluntary muscle activation and muscle atrophy in the
early loss of quadriceps strength after surgery.
Methods: Twenty patients with unilateral knee osteoarthritis were tested an average of ten days before and twentyseven
days after primary total knee arthroplasty. Quadriceps strength and voluntary muscle activation were measured
with use of a burst-superimposition technique in which a supramaximal burst of electrical stimulation is superimposed
on a maximum voluntary isometric contraction. Maximal quadriceps cross-sectional area was assessed with
use of magnetic resonance imaging.
Results: Postoperatively, quadriceps strength was decreased by 62%, voluntary activation was decreased by 17%,
and maximal cross-sectional area was decreased by 10% in comparison with the preoperative values; these differences
were significant (p < 0.01). Collectively, failure of voluntary muscle activation and atrophy explained 85% of the
loss of quadriceps strength (p < 0.001). Multiple linear regression analysis revealed that failure of voluntary activation
contributed nearly twice as much as atrophy did to the loss of quadriceps strength. The severity of knee pain with
muscle contraction did not change significantly compared with the preoperative level (p = 0.31). Changes in knee
pain during strength-testing did not account for a significant amount of the change in voluntary activation (p = 0.14).
Conclusions: Patients who are managed with total knee arthroplasty have profound impairment of quadriceps
strength one month after surgery. This impairment is predominantly due to failure of voluntary muscle activation, and
it is also influenced, to a lesser degree, by muscle atrophy. Knee pain with muscle contraction played a surprisingly
small role in the reduction of muscle activation
A Comprehensive Ex Vivo Functional Analysis of Human NKT Cells Reveals Production of MIP1-α and MIP1-β, a Lack of IL-17, and a Th1-Bias in Males
NKT cells contribute to the modulation of immune responses and are believed to be important in the pathogenesis of autoimmune and infectious diseases, as well as cancer. Variations in the composite NKT cytokine response may determine individual disease susceptibility or severity. Due to low frequencies in peripheral blood, knowledge of the breadth of ex vivo human NKT cell functions has been limited. To bridge this gap, we studied highly purified NKT cells from PBMC of healthy donors and assessed the production of 27 effector functions using sensitive Elispot and multiplex bead assays. We found the ex vivo human NKT cell response is predominantly comprised of the chemokines MIP1-α, and MIP1-β as well as the Th1 cytokines IFN-γ and TNF-α. Although lower in magnitude, there was also significant production of IL-2, IL-4, and perforin after mitogen stimulation. Surprisingly, little/no IL-5, IL-6, IL-10, or IL-13 was detected, and no subjects' NKT cells produced IL-17. Comparison of the NKT functional profiles between age-matched male and female subjects revealed similar IL-4 responses, but higher frequencies of cells producing IFN-γ and MIP1-α, from males. There were no gender differences in the circulating NKT subset distribution. These findings implicate chemokines as a major mechanism by which NKT cells control responses in humans. In addition, the panoply of Th2 and Th17 cytokine secretion by NKT cells from healthy donors may not be as pronounced as previously believed. NKT cells may therefore contribute to the gender bias found in many diseases
Fellowships in Community Pharmacy Research: Experiences of Five Schools and Colleges of Pharmacy
Objective To describe common facilitators, challenges, and lessons learned in 5 schools and colleges of pharmacy in establishing community pharmacy research fellowships.
Setting: Five schools and colleges of pharmacy in the United States.
Practice description: Schools and colleges of pharmacy with existing community partnerships identified a need and ability to develop opportunities for pharmacists to engage in advanced research training.
Practice innovation: Community pharmacy fellowships, each structured as 2 years long and in combination with graduate coursework, have been established at the University of Pittsburgh, Purdue University, East Tennessee State University, University of North Carolina at Chapel Hill, and The Ohio State University.
Evaluation: Program directors from each of the 5 community pharmacy research fellowships identified common themes pertaining to program structure, outcomes, and lessons learned to assist others planning similar programs.
Results: Common characteristics across the programs include length of training, prerequisites, graduate coursework, mentoring structure, and immersion into a pharmacist patient care practice. Common facilitators have been the existence of strong community pharmacy partnerships, creating a fellowship advisory team, and networking. A common challenge has been recruitment, with many programs experiencing at least one year without filling the fellowship position. All program graduates (n = 4) have been successful in securing pharmacy faculty positions.
Conclusion: Five schools and colleges of pharmacy share similar experiences in implementing community pharmacy research fellowships. Early outcomes show promise for this training pathway in growing future pharmacist-scientists focused on community pharmacy practice
Recommended from our members
Retinal mid-peripheral capillary free zones are enlarged in cognitively unimpaired older adults at high risk for Alzheimer’s disease
BackgroundCompared to standard neuro-diagnostic techniques, retinal biomarkers provide a probable low-cost and non-invasive alternative for early Alzheimer's disease (AD) risk screening. We have previously quantified the periarteriole and perivenule capillary free zones (mid-peripheral CFZs) in cognitively unimpaired (CU) young and older adults as novel metrics of retinal tissue oxygenation. There is a breakdown of the inner retinal blood barrier, pericyte loss, and capillary non-perfusion or dropout in AD leading to potential enlargement of the mid-peripheral CFZs. We hypothesized the mid-peripheral CFZs will be enlarged in CU older adults at high risk for AD compared to low-risk individuals.Methods20 × 20° optical coherence tomography angiography images consisting of 512 b-scans, 512 A-scans per b-scan, 12-µm spacing between b-scans, and 5 frames averaged per each b-scan location of the central fovea and of paired major arterioles and venules with their surrounding capillaries inferior to the fovea of 57 eyes of 37 CU low-risk (mean age: 66 years) and 50 eyes of 38 CU high-risk older adults (mean age: 64 years; p = 0.24) were involved in this study. High-risk participants were defined as having at least one APOE e4 allele and a positive first-degree family history of AD while low-risk participants had neither of the two criteria. All participants had Montreal Cognitive Assessment scores ≥ 26. The mid-peripheral CFZs were computed in MATLAB and compared between the two groups.ResultsThe periarteriole CFZ of the high-risk group (75.8 ± 9.19 µm) was significantly larger than that of the low-risk group (71.3 ± 7.07 µm), p = 0.005, Cohen's d = 0.55. The perivenule CFZ of the high-risk group (60.4 ± 8.55 µm) was also significantly larger than that of the low-risk group (57.3 ± 6.40 µm), p = 0.034, Cohen's d = 0.42. There were no significant differences in foveal avascular zone (FAZ) size, FAZ effective diameter, and vessel density between the two groups, all p > 0.05.ConclusionsOur results show larger mid-peripheral CFZs in CU older adults at high risk for AD, with the potential for the periarteriole CFZ to serve as a novel retinal vascular biomarker for early AD risk detection
Recommended from our members
Consistency of parent-report SLC6A1 data in Simons Searchlight with Provider-Based Publications
Background
SLC6A1-related disorder is a recently identified, rare, genetic neurodevelopmental disorder that is associated with loss-of-function variants in SLC6A1. This gene encodes GABA transporter type I that is responsible for re-uptake of GABA from the synapse into the pre-synaptic terminal or circulating neuroglia. Based upon retrospective review of published cases and available research databases including Epi25 collective and SLC6A1 Connect patient database, the phenotypic spectrum is broad and includes developmental delay, epilepsy, and autism or autistic traits. SLC6A1 is one of the genes included in the Simons Searchlight registry, which includes standardized data collection across genetically identified neurodevelopmental conditions.
Methods
In this study, we compare parent-report measures of phenotypic features in the Simons Searchlight registry to previously published, provider-reported cases to assess if parent-report measures are consistent with what has been reported in the literature.
Results
There were 116 participants in the provider-reported dataset compared to 43 individuals in the caregiver-reported dataset. Carriers in Searchlight had 83 unique pathogenic or likely pathogenic variants in SLC6A1, which were predominantly missense or nonsense variants. There was no significant difference between groups for the prevalence of developmental delay, ASD, or ADHD. Caregivers more often reported hypotonia, while epilepsy was slightly more frequently reported by providers.
Conclusions
We propose that standardized parent-report data collection methods are consistent with provider reports on many core features of SLC6A1-related disorder. The availability of patient registries and standardized natural history studies may fill an important need in clinical trial readiness programs, with larger sample sizes than smaller published case series
- …