1,798 research outputs found
DECEPTIVE SIGNALS: THE ANIMAL KINGDOM AND COUNTERDECEPTION
Knowledge of signals—particularly deception and counterdeception—is a crucial component of both diplomacy and war. The use and evaluation of costly signals are both central to everyday politics and war as they are pervasive in the natural world. As such, this thesis explores the underlying strategic logic of animal signaling and how this benefits us in daily foreign policy challenges. The detection of incongruous cues can index the need for further evaluation of signals while costly signals that take up significant resources are unlikely to have been sent casually. Future studies should further identify other ideas not explored in a foreign policy context and make further use of solutions to problems that predate human beings.Major, United States ArmyApproved for public release. Distribution is unlimited
The current state of per oral endoscopic myotomy for achalasia.
Achalasia is an acquired neuromuscular disorder that has been treated using a variety of modalities throughout medical history. Recently, the technique of per oral endoscopic myotomy (POEM) was introduced to treat the disease using a truly minimally invasive, natural orifice technique that is rapidly being adopted across the world. This review outlines the development of POEM, the technique itself, and gives a comparison to other procedures, specifically laparoscopic Heller myotomy (LHM)
Impact of traumatic upper-extremity amputation on the outcome of injury caused by an antipersonnel improvised explosive device
Background: We have previously reported a higher than expected rate of upper-extremity amputation (UEA) in victims of an antipersonnel improvised explosive device (AP-IED) compared with a similar cohort injured by antipersonnel mines (APM). The goal of this study was to describe the rate, severity and impact of UAE caused by an AP-IED. Methods: We analyzed a prospective database of 100 consecutive dismounted AP-IED victims with pattern 1 injuries to compare the outcomes of the cohort with UEA to that without. Results: We found that UEA (8 above elbow, 19 below elbow, 1 through elbow, 3 hand, 15 digit(s)) was much more prevalent with AP-IED than with APM (40% v. 6%, p \u3c 0.001). In addition, UEA was associated with a higher rate of multiple amputations (39 [98%] v. 32 [53%], p \u3c 0.001), bilateral lower-extremity amputation (LEA; 33 [82.5%] v. 30 [53.3%], p = 0.003) and facial injury (8 [20%] v. 4 [6.4%], p = 0.044), but not with pelvic disruption (10 [25%]), genitoperineal mutilation (19 [48%]), eye injury (6 [15%]), or skull fracture (6 [15%]). The fatality rate was higher in patients with UEA than in those without (12 [30%] v. 7 [12%], p = 0.022). Conclusion: Upper-extremity amputation is more prevalent with AP-IED than APM. Presence of UEA is associated with more severe injury and increased risk of death in AP-IED victims. Upper-limb injury has significant consequences for rehabilitation from LEA, which universally accompanies UEA in AP-IED victims. Upper-extremity injury should be amenable to prevention by innovative personal protective equipment designed to protect the flexed elbow
Gastric hibernoma: a novel location and presentation of a rare tumor.
We present a case of gastric hibernoma, an unusual tumor with a location novel to the literature. A 39-year-old female presented with one year of upper gastrointestinal bleeding and dysphagia. Gastroenterology performed an esophagogastroduodenoscopy with ultrasound and identified a 6 cm mass within the muscularis propria of the antrum. Computed tomography demonstrated a 9.7 × 7.8 × 4.8 c
Outcomes of Fusions From the Cervical Spine to the Pelvis.
Study designRetrospective cohort study.ObjectiveDetermine the indications, complications, and clinical outcomes in patients requiring fusions from the cervical spine to the pelvis. Several investigators have examined fusions from the thoracic spine to the sacrum, but no similar study has been performed for cervical-to-pelvis fusions.MethodsPatients from 2003 to 2014 with an upper instrumented vertebrae (UIV) in the cervical spine (any level) and a lower instrumented vertebrae (LIV) in the sacrum or pelvis were included in the study. Those with infectious or acute trauma-related deformities were excluded. Patient demographics, medical history, diagnosis, operative procedure, and health-related quality of life measures were analyzed. Student's t test, Kruskal-Wallis test, and χ2 test were used as appropriate; significance was set at P < .05 for all tests.ResultsFifty-five patients met inclusion criteria for the study. Average follow-up was 2.8 years. Proximal junctional kyphosis was the most common indication for cervical-to-pelvis fusions (36%). The most common UIV was C2 (29%) followed by C7 (24%). There was an average 31° correction in maximum kyphosis and a 3.3 cm improvement in sagittal vertical axis. In adults, the rate of complication was 71.4%, with a major complication rate of 39.3% and reoperation rate of 53.6%. There was significant improvement in the Scoliosis Research Society (SRS-22r) score (3.0 to 3.5; P < .01).ConclusionProximal junctional kyphosis is the most common indication for patients requiring fusion to the cervical spine. Adult patients incur a significant risk of major complications and reoperations. However, significant improvement in SRS-22r outcomes are noted in these patients
Three-Point Correlation Functions of SDSS Galaxies: Luminosity and Color Dependence in Redshift and Projected Space
The three-point correlation function (3PCF) provides an important view into
the clustering of galaxies that is not available to its lower order cousin, the
two-point correlation function (2PCF). Higher order statistics, such as the
3PCF, are necessary to probe the non-Gaussian structure and shape information
expected in these distributions. We measure the clustering of spectroscopic
galaxies in the Main Galaxy Sample of the Sloan Digital Sky Survey (SDSS),
focusing on the shape or configuration dependence of the reduced 3PCF in both
redshift and projected space. This work constitutes the largest number of
galaxies ever used to investigate the reduced 3PCF, using over 220,000 galaxies
in three volume-limited samples. We find significant configuration dependence
of the reduced 3PCF at 3-27 Mpc/h, in agreement with LCDM predictions and in
disagreement with the hierarchical ansatz. Below 6 Mpc/h, the redshift space
reduced 3PCF shows a smaller amplitude and weak configuration dependence in
comparison with projected measurements suggesting that redshift distortions,
and not galaxy bias, can make the reduced 3PCF appear consistent with the
hierarchical ansatz. The reduced 3PCF shows a weaker dependence on luminosity
than the 2PCF, with no significant dependence on scales above 9 Mpc/h. On
scales less than 9 Mpc/h, the reduced 3PCF appears more affected by galaxy
color than luminosty. We demonstrate the extreme sensitivity of the 3PCF to
systematic effects such as sky completeness and binning scheme, along with the
difficulty of resolving the errors. Some comparable analyses make assumptions
that do not consistently account for these effects.Comment: 27 pages, 21 figures. Updated to match accepted version. Published in
Ap
Reduced Coupling of Oxidative Phosphorylation In Vivo Precedes Electron Transport Chain Defects Due to Mild Oxidative Stress in Mice
Oxidative stress and mitochondrial function are at the core of many degenerative conditions. However, the interaction between oxidative stress and in vivo mitochondrial function is unclear. We used both pharmacological (2 week paraquat (PQ) treatment of wild type mice) and transgenic (mice lacking Cu, Zn-superoxide dismutase (SOD1−/−)) models to test the effect of oxidative stress on in vivo mitochondrial function in skeletal muscle. Magnetic resonance and optical spectroscopy were used to measure mitochondrial ATP and oxygen fluxes and cell energetic state. In both models of oxidative stress, coupling of oxidative phosphorylation was significantly lower (lower P/O) at rest in vivo in skeletal muscle and was dose-dependent in the PQ model. Despite this reduction in efficiency, in vivo mitochondrial phosphorylation capacity (ATPmax) was maintained in both models, and ex vivo mitochondrial respiration in permeabilized muscle fibers was unchanged following PQ treatment. In association with the reduced P/O, PQ treatment led to a dose-dependent reduction in PCr/ATP ratio and increased phosphorylation of AMPK. These results indicate that oxidative stress uncouples oxidative phosphorylation in vivo and results in energetic stress in the absence of defects in the mitochondrial electron transport chain
The Role of Entrepreneur-Venture Fit in Online Home-based Entrepreneurship: A Systematic Literature Review
Home-based businesses and their founders represent an important, but under-researched facet of entrepreneurship. Far from being small, hobby-businesses with little economic impact, home-based business make significant contribution to national economies in terms of both turnover and employment. Online home-based businesses have been recognised as an important and distinct sector of the home-based business domain, offering unique opportunity for innovation and business diversity. The paper presents a systematic literature review of extant research on online home-based entrepreneurs and their businesses. The findings of the review are structured and discussed using the theoretical lens of entrepreneur-venture fit. Use of this lens allows the study to bring coherence to previously fragmented extant studies, providing a basis for future research in this domain. The study also develops a novel model of entrepreneur-venture fit in the specific case of online home-based businesses. This allows us to suggest five positive interactions between entrepreneurial and venture characteristics. It also allows us to suggest a number of previously unidentified negative interactions, which may result in entrepreneurs becoming ‘locked-in’ and suffering multiple sources of stress
Raptor wing morphing with flight speed
In gliding flight, birds morph their wings and tails to control their flight trajectory and speed. Using high-resolution videogrammetry, we reconstructed accurate and detailed three-dimensional geometries of gliding flights for three raptors (barn owl, Tyto alba; tawny owl, Strix aluco, and goshawk, Accipiter gentilis). Wing shapes were highly repeatable and shoulder actuation was a key component of reconfiguring the overall planform and controlling angle of attack. The three birds shared common spanwise patterns of wing twist, an inverse relationship between twist and peak camber, and held their wings depressed below their shoulder in an anhedral configuration. With increased speed, all three birds tended to reduce camber throughout the wing, and their wings bent in a saddle-shape pattern. A number of morphing features suggest that the coordinated movements of the wing and tail support efficient flight, and that the tail may act to modulate wing camber through indirect aeroelastic control
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