39 research outputs found
High-speed Hydrodynamic Characteristics of a Flat Plate and 20 Degrees Dead-rise Surface in Unsymmetrical Planing Conditions
Minimally Invasive Ultrasound‐Guided Carpal Tunnel Release: Preliminary Clinical Results
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146278/1/jum14618.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146278/2/jum14618_am.pd
Can Ultrasound Be Used to Improve the Palpation Skills of Physicians in Training? A Prospective Study
BackgroundAccurate diagnosis of musculoskeletal disorders relies heavily on the physical examination, including accurate palpation of musculoskeletal structures. The literature suggests that there has been a deterioration of physical examination skills among medical students and residents, in part due to increased reliance on advanced imaging. It has been shown that knowledge of musculoskeletal anatomy and physical examination skills improve with the use of ultrasound; however, the literature is limited.ObjectiveTo determine whether ultrasound can improve the ability of physicians in training (residents) to palpate the long head of the biceps tendon (LHBT) in the bicipital groove.DesignProspective study design.SettingTertiary care center.ParticipantsTen physical medicine and rehabilitation residents served as subjects. Exclusion criteria included the presence of any condition that precluded their ability to palpate. Three volunteers were used as models. Model exclusion criteria included anything that distorted normal shoulder anatomy or inhibited examiner palpation. Three investigators with experience performing diagnostic musculoskeletal ultrasound were used to confirm palpation attempts.MethodsSubjects attempted to palpate the LHBT bilaterally in the bicipital groove of each model. Investigators assessed the accuracy of the palpation attempt using real‐time ultrasonography. Subjects participated in a 30‐minute ultrasound‐assisted training session learning how to palpate the LHBT in the bicipital groove with ultrasound confirmation. After the ultrasound training session, subjects again attempted to palpate the LHBT in the bicipital groove of each model with investigator confirmation.Main Outcome MeasurementsLHBT palpation accuracy rates preintervention versus postintervention.ResultsPretraining LHBT palpation accuracy was 20% (12/60 attempts). Post‐ultrasound training session accuracy was 51.7% (31/60 attempts; P ≤ .001).ConclusionsOur findings demonstrate that palpation accuracy improves after ultrasound assisted LHBT palpation training. These data suggest that the use of ultrasound may be beneficial when teaching musculoskeletal palpation skills to health care professionals.Level of EvidenceIIPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146948/1/pmr2730.pd
Effects of warming and drought on potential N2O emissions and denitrifying bacteria abundance in grasslands with different land-use
Increased warming in spring and prolonged summer drought may alter soil microbial denitrification. We measured potential denitrification activity and denitrifier marker gene abundances (nirK, nirS, nosZ) in grasslands soils in three geographic regions characterized by site-specific land-use indices (LUI) after warming in spring, at an intermediate sampling and after summer drought. Potential denitrification was significantly increased by warming, but did not persist over the intermediate sampling. At the intermediate sampling, the relevance of grassland land-use intensity was reflected by increased potential N2O production at sites with higher LUI. Abundances of total bacteria did not respond to experimental warming or drought treatments, displaying resilience to minor and short-term effects of climate change. In contrast, nirS- and nirK-type denitrifiers were more influenced by drought in combination with LUI and pH, while the nosZ abundance responded to the summer drought manipulation. Land-use was a strong driver for potential denitrification as grasslands with higher LUI also had greater potentials for N2O emissions. We conclude that both warming and drought affected the denitrifying communities and the potential denitrification in grassland soils. However, these effects are overruled by regional and site-specific differences in soil chemical and physical properties which are also related to grassland land-use intensit
Nitrogen isotopic analysis of carbonate-bound organic matter in modern and fossil fish otoliths
The nitrogen isotopic composition (δ^(15)N) of otolith-bound organic matter (OM) is a potential source of information on dietary history of bony fishes. In contrast to the δ^(15)N of white muscle tissue, the most commonly used tissue for ecological studies, the δ^(15)N of otolith-bound OM (δ^(15)N_(oto)) provides a record of whole life history. More importantly, δ^(15)N_(oto) can be measured in contexts where tissue is not available, for example, in otolith archives and sedimentary deposits. The utility and robustness of otolith δ^(15)N analysis was heretofore limited by the low N content of otoliths, which precluded the routine measurement of individual otoliths as well as the thorough cleaning of otolith material prior to analysis. Here, we introduce a new method based on oxidation to nitrate followed by bacterial conversion to N_2O. The method requires 200-fold less N compared to traditional combustion approaches, allowing for thorough pre-cleaning and replicated analysis of individual otoliths of nearly any size. Long term precision of δ^(15)N_(oto) is 0.3‰. Using an internal standard of Atlantic cod (Gadus morhua) otoliths, we examine the parameters of the oxidative cleaning step with regard to oxidant (potassium persulfate and sodium hypochlorite), temperature, and time. We also report initial results that verify the usefulness of δ^(15)N_(oto) for ecological studies. For three salmonid species, left and right otoliths from the same fish are indistinguishable. We find that the δ^(15)N_(oto) of pink salmon (Oncorhynchus gorbuscha) is related to the size of the fish for this species. We find that intra-cohort δ^(15)N_(oto) standard deviation for wild pink salmon, farmed brown trout (Salmo trutta), and farmed rainbow trout (Oncorhynchus mykiss) are all 0.4‰ or less, suggesting that δ^(15)N_(oto) will be valuable for population-level studies. Lastly, our protocol yields reproducible data for both δ^(15)N_(oto) and otolith N content in 17th century Atlantic cod otoliths. We find that 17th century cod are approximately 2 ‰ higher than modern cod, arguably consistent with either the larger size of the otoliths (and thus inferred for the fish) or with changes in baseline (primary producer) δ^(15)N in the modern coastal ocean compared to the past. All told, the results of this study bode well for the utility of otolith-bound δ15N for investigating the environment and ecology of modern and past fish
Recommended from our members
Nitrogen isotopic analysis of carbonate-bound organic matter in modern and fossil fish otoliths
The nitrogen isotopic composition (δ^(15)N) of otolith-bound organic matter (OM) is a potential source of information on dietary history of bony fishes. In contrast to the δ^(15)N of white muscle tissue, the most commonly used tissue for ecological studies, the δ^(15)N of otolith-bound OM (δ^(15)N_(oto)) provides a record of whole life history. More importantly, δ^(15)N_(oto) can be measured in contexts where tissue is not available, for example, in otolith archives and sedimentary deposits. The utility and robustness of otolith δ^(15)N analysis was heretofore limited by the low N content of otoliths, which precluded the routine measurement of individual otoliths as well as the thorough cleaning of otolith material prior to analysis. Here, we introduce a new method based on oxidation to nitrate followed by bacterial conversion to N_2O. The method requires 200-fold less N compared to traditional combustion approaches, allowing for thorough pre-cleaning and replicated analysis of individual otoliths of nearly any size. Long term precision of δ^(15)N_(oto) is 0.3‰. Using an internal standard of Atlantic cod (Gadus morhua) otoliths, we examine the parameters of the oxidative cleaning step with regard to oxidant (potassium persulfate and sodium hypochlorite), temperature, and time. We also report initial results that verify the usefulness of δ^(15)N_(oto) for ecological studies. For three salmonid species, left and right otoliths from the same fish are indistinguishable. We find that the δ^(15)N_(oto) of pink salmon (Oncorhynchus gorbuscha) is related to the size of the fish for this species. We find that intra-cohort δ^(15)N_(oto) standard deviation for wild pink salmon, farmed brown trout (Salmo trutta), and farmed rainbow trout (Oncorhynchus mykiss) are all 0.4‰ or less, suggesting that δ^(15)N_(oto) will be valuable for population-level studies. Lastly, our protocol yields reproducible data for both δ^(15)N_(oto) and otolith N content in 17th century Atlantic cod otoliths. We find that 17th century cod are approximately 2 ‰ higher than modern cod, arguably consistent with either the larger size of the otoliths (and thus inferred for the fish) or with changes in baseline (primary producer) δ^(15)N in the modern coastal ocean compared to the past. All told, the results of this study bode well for the utility of otolith-bound δ15N for investigating the environment and ecology of modern and past fish
Multiple Measurements, Elusive Agreement, and Unstable Outcomes in the Study of Regime Change
Trust in government regarding COVID-19 and its associations with preventive health behaviour and prosocial behaviour during the pandemic: a cross-sectional and longitudinal study
Background. The effective implementation of government policies and measures for controlling the coronavirus disease 2019 (COVID-19) pandemic requires compliance from the public. This study aimed to examine cross-sectional and longitudinal associations of trust ingovernment regarding COVID-19 control with the adoption of recommended health behaviours and prosocial behaviours, and potential determinants of trust in government duringthe pandemic.Methods. This study analysed data from the PsyCorona Survey, an international project onCOVID-19 that included 23 733 participants from 23 countries (representative in age andgender distributions by country) at baseline survey and 7785 participants who also completedfollow-up surveys. Specification curve analysis was used to examine concurrent associationsbetween trust in government and self-reported behaviours. We further used structural equation model to explore potential determinants of trust in government. Multilevel linear regressions were used to examine associations between baseline trust and longitudinal behavioural changes.Results. Higher trust in government regarding COVID-19 control was significantly associatedwith higher adoption of health behaviours (handwashing, avoiding crowded space, self-quarantine) and prosocial behaviours in specification curve analyses (median standardised β =0.173 and 0.229, p < 0.001). Government perceived as well organised, disseminating clear messages and knowledge on COVID-19, and perceived fairness were positively associated withtrust in government (standardised β = 0.358, 0.230, 0.056, and 0.249, p < 0.01). Higher trustat baseline survey was significantly associated with lower rate of decline in health behavioursover time ( p for interaction = 0.001).Conclusions. These results highlighted the importance of trust in government in the control of Covid-19
Ultrasound-Guided Carpal Tunnel Release Using Dynamic Expansion of the Transverse Safe Zone in a Patient With Postpolio Syndrome: A Case Report.
The prevalence of carpal tunnel syndrome (CTS) in patients with postpolio syndrome occurs at a rate of 22%. Irrespective of those with CTS, 74% of postpolio patients weight bear through their arms for ambulation or transfers. As open carpal tunnel release is performed along the weight-bearing region of the wrist, their functional independence may be altered while recovering. This case demonstrates that ultrasound-guided carpal tunnel release was successfully performed in a patient with postpolio syndrome allowing him to immediately weight bear through his hands after the procedure so he could recover at home
Recommended from our members
NACA Technical Notes
Note presenting the results of an investigation made to obtain the wetted areas, three components of planing forces, and the three components of moments acting on a 0 degree and a 20 degree dead-rise surface in high-speed, unsymmetrical planing conditions. The collected test data are presented in summary plots which are readily applicable for use in determining the lift, drag, side force, pitching moment, rolling moment, and yawing moment