3,431 research outputs found
Arthroscopic transosseous rotator cuff repair: A prospective study on cost savings, surgical time, and outcomes
Objectives: Health expenditures in the United States are outpacing national income, and affordability has become a major policy issue. Over 500,000 rotator cuff repairs (RCR) are performed annually in the United States making RCR a potential source of cost savings. Arthroscopic trans-osseous equivalent (TOE) repair using a double row of anchors has shown superior biomechanical strength compared to other techniques, but at a higher cost. The arthroscopic transosseous (TO) repair is a novel technique allowing arthroscopic rotator cuff repair to be performed without suture anchors. Arthroscopic TO repair may be a means to provide similarly excellent patient outcomes while lowering the cost of care. The primary purpose is to compare the price differential and time of surgery for an arthroscopic rotator cuff repair using anchorless TO repair verses an anchor trans-osseous equivalent (TOE) repair. A secondary purpose of the study was to evaluate outcomes at 6 months postoperatively. Methods: A prospective, case-controlled study evaluating arthroscopic rotator cuff repair using two techniques was performed. The study group consisting of 21 patients undergoing TO repair was compared to a control group consisting of 22 patients undergoing TOE repair. The groups were controlled for size of tear, biceps treatment, acromioplasty, distal clavicle excision, and labral pathology. The primary outcome measures were surgical time as well as total cost of implants and equipment for each surgery, determined by an independent third party, Atlanticare Hospital. Secondary outcomes were changes in the SST, VAS, and SANE scores. Results: Mean total surgical implant/equipment cost per procedure for TOE repair was 1204.97 (SD 330.69; p\u3c0.0001). Mean cut to close time for TOE repair was 85 minutes (95% CI is 77-90) verses 74 (95% CI = 71-98) for TO repair. A log rank test revealed no difference in time (p =0.95). A linear regression model was developed to evaluate the change in SST, VAS, and SANE scores from pre-op to 6 months follow-up. Our study was underpowered but no difference in outcome was observed. Conclusion: Arthroscopic TO rotator cuff repair is a cost savings and time neutral technique compared to TOE repair. A mean of $1100 can be saved in surgical cost per case. In a country that performs over 500,000 RCRs annually, utilizing a TO repair technique can provide substantial cost savings to the healthcare system. © The Author(s) 2015
Conditionality Contaminates Conservation: Structural Adjustment and Land Protection in Less-Developed Nations
The destruction that human beings cause the natural environment is so catastrophic that the current era has now been labeled the “Sixth Extinction.” Conservation and the preservation of species and ecosystems is a leading strategy in preventing biodiversity loss and preserving natural ecosystems. As threats to biodiversity mount, it is imperative that social scientists explore the macro-level processes that influence conservation areas, especially in poorer nations where the majority of biodiverse zones are located. This study explores the impact of structural adjustment policies on the ability of less-developed nations to designate land for conservation. We use ordinary least squares (OLS) regression to examine the influence of IMF conditionality on levels of terrestrial protected areas for 86 less-developed nations. The results confirm our hypothesis that nations undergoing IMF structural adjustment have a smaller percentage of land devoted to terrestrial protected areas than nations not undergoing structural adjustment. Neoliberal approaches that encourage privatization and deregulation ultimately impair less-developed nations’ abilities to make conservation a priority
Perceptual adjustment queries and an inverted measurement paradigm for low-rank metric learning
We introduce a new type of query mechanism for collecting human feedback,
called the perceptual adjustment query ( PAQ). Being both informative and
cognitively lightweight, the PAQ adopts an inverted measurement scheme, and
combines advantages from both cardinal and ordinal queries. We showcase the PAQ
in the metric learning problem, where we collect PAQ measurements to learn an
unknown Mahalanobis distance. This gives rise to a high-dimensional, low-rank
matrix estimation problem to which standard matrix estimators cannot be
applied. Consequently, we develop a two-stage estimator for metric learning
from PAQs, and provide sample complexity guarantees for this estimator. We
present numerical simulations demonstrating the performance of the estimator
and its notable properties.Comment: 42 pages, 6 figure
Associations of Metabolic Variables with Electrocardiographic Measures of Sympathovagal Balance in Healthy Young Adults
Conservation systematics of the shield-backed trapdoor spiders of the nigrum-group (Mygalomorphae, idiopidae, idiosoma): Integrative taxonomy reveals a diverse and threatened fauna from south-western Australia [dataset]
Supplementary material from: Rix MG, Huey JA, Cooper SJB, Austin AD, Harvey MS (2018) Conservation systematics of the shield-backed trapdoor spiders of the nigrum-group (Mygalomorphae, Idiopidae, Idiosoma): integrative taxonomy reveals a diverse and threatened fauna from south-western Australia. ZooKeys 756: 1-121. https://doi.org/10.3897/zookeys.756.24397
Supplementary material 1: Atlas of morphology : Explanation note: Atlas of morphology for shield-backed trapdoor spiders of the Idiosoma nigrum-group, illustrating a representative selection of male specimens for each species, in five standard views.
Supplementary material 2: GenBank data : Explanation note: Spreadsheet of specimens sequenced for the molecular analyses, with associated collection data and GenBank accession numbers.
Supplementary material 3: COI dataset : Explanation note: Nexus file of the aligned COI dataset for 82 taxa.
Supplementary material 4: FULL dataset : Explanation note: Nexus file of the aligned FULL dataset for 82 taxa.
Supplementary material 5: COI p-distances : Explanation note: Spreadsheet with matrix of COI p-distances for 61 sequenced specimens of Idiosoma in the nigrum-group, along with a summary of mean inter- and intra-specific p-distances
Metabolic Energy Correlates of Heart Rate Variability Spectral Power Associated with a 900-Calorie Challenge
We studied healthy males challenged with a 900 Cal test beverage and correlated EE with the raw (ms2) and normalized units (nu) of total power (TP), low frequency/high frequency (LF/HF) and VLF spectral power of heart rate variability (HRV). The correlations were evaluated during 20 min of normal breathing (NB, control) and 20 min of paced breathing (PB) at 12 breaths·min−1 (0.2 Hz). EE was not significantly correlated with any of the HRV variables before the metabolic challenge. After the challenge, EE was positively correlated with LF/HF and with VLF; VLF was also positively correlated with LF/HF during both NB and PB. These findings suggest that EE may be a correlate of LF/HF and of VLF spectral power of HRV in healthy adolescent/young adult males. The association of lower resting energy expenditure with lower amounts of VLF spectral power may occur in individuals with predilections for obese phenotypes
Abnormal Trafficking of Endogenously Expressed BMPR2 Mutant Allelic Products in Patients with Heritable Pulmonary Arterial Hypertension
More than 200 heterozygous mutations in the type 2 BMP receptor gene, BMPR2, have been identified in patients with Heritable Pulmonary Arterial Hypertension (HPAH). More severe clinical outcomes occur in patients with BMPR2 mutations by-passing nonsense-mediated mRNA decay (NMD negative mutations). These comprise 40% of HPAH mutations and are predicted to express BMPR2 mutant products. However expression of endogenous NMD negative BMPR2 mutant products and their effect on protein trafficking and signaling function have never been described. Here, we characterize the expression and trafficking of an HPAH-associated NMD negative BMPR2 mutation that results in an in-frame deletion of BMPR2 EXON2 (BMPR2ΔEx2) in HPAH patient-derived lymphocytes and in pulmonary endothelial cells (PECs) from mice carrying the same in-frame deletion of Exon 2 (Bmpr2 (ΔEx2/+) mice). The endogenous BMPR2ΔEx2 mutant product does not reach the cell surface and is retained in the endoplasmic reticulum. Moreover, chemical chaperones 4-PBA and TUDCA partially restore cell surface expression of Bmpr2ΔEx2 in PECs, suggesting that the mutant product is mis-folded. We also show that PECs from Bmpr2 (ΔEx2/+) mice have defects in the BMP-induced Smad1/5/8 and Id1 signaling axis, and that addition of chemical chaperones restores expression of the Smad1/5/8 target Id1. These data indicate that the endogenous NMD negative BMPRΔEx2 mutant product is expressed but has a folding defect resulting in ER retention. Partial correction of this folding defect and restoration of defective BMP signaling using chemical chaperones suggests that protein-folding agents could be used therapeutically in patients with these NMD negative BMPR2 mutations
Numerical simulations of string networks in the Abelian-Higgs model
We present the results of a field theory simulation of networks of strings in
the Abelian Higgs model. Starting from a random initial configuration we show
that the resulting vortex tangle approaches a self-similar regime in which the
length density of lines of zeros of reduces as . We demonstrate
that the network loses energy directly into scalar and gauge radiation. These
results support a recent claim that particle production, and not gravitational
radiation, is the dominant energy loss mechanism for cosmic strings. This means
that cosmic strings in Grand Unified Theories are severely constrained by high
energy cosmic ray fluxes: either they are ruled out, or an implausibly small
fraction of their energy ends up in quarks and leptons.Comment: 4pp RevTeX, 3 eps figures, clarifications and new results included,
to be published in Phys. Rev. Let
Real-world performance of catalytic converters
This paper investigates experimentally the performance of a three-way catalytic (TWC) converter for real-world passenger car driving in the United Kingdom. A systematic approach is followed for the analysis using a Euro-IV vehicle coupled with a TWC converter. The analysis shows that the real-world performance of TWC converters is significantly different from the performance established on legislative test cycles. It is identified that a light-duty passenger vehicle certified for Euro-IV emissions reaches the gross polluting threshold limits during real-world driving conditions. This result is shown to have implications for overall emission levels and the use of remote emissions sensing and on-board diagnostics (OBD) systems
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