The reliability of physical examination in diagnosing arterial injury in penetrating trauma to extremities: A first look at different anatomical regions and injury mechanisms

Background. The accuracy of physical examination to exclude arterial injury in penetrating trauma to extremities has been well established. Objectives. To determine whether the accuracy of physical examination to exclude arterial injury is similar to that of a computed tomography arteriogram (CTA) for different anatomical regions and mechanisms of injury, and in patients with concomitant fractures compared with those without. Methods. A retrospective review was conducted on all patients who underwent CTA for penetrating injuries to an extremity between 1 June 2016 and 30 June 2017. The presence of arterial injuries was noted, and these were grouped into anatomical areas. Clinical notes were reviewed for the presence of hard signs of arterial injury at initial examination. Results. A total of 220 lower limb and 133 upper limb CTAs were included. The mean patient age was 28.9 years (range 11 - 68). The overall sensitivity of physical examination in detecting a CTA-confirmed arterial injury was 95.3% (95% confidence interval (CI) 88.4 - 98.7), with a specificity of 93.9% (95% CI 90.2 - 96.4). Physical examination of the thigh had the highest specificity of 96.4% (95% CI 91.8 - 98.8), followed by the lower leg at 94.4% (95% CI 81.3 - 99.3), the upper arm at 89.6% (95% CI 79.7 - 95.7) and the forearm at 77.8% (95% CI 40.0 - 97.2). For gunshot wounds the specificity was 96.1% (95% CI 92.4 - 98.3), while for stab wounds it was 86.8% (95% CI 74.7 - 94.5). Conclusions. This study agrees with current literature indicating that physical examination has high specificity in detecting arterial injury in the setting of penetrating trauma to an extremity. However, it shows that the specificity is not equal for all anatomical regions or mechanisms of injury

Time-randomized stopping problems for a family of utility functions

This paper studies stopping problems of the form $V=\inf_{0 \leq \tau \leq T} \mathbb{E}[U(\frac{\max_{0\le s \le T} Z_s }{Z_\tau})]$ for strictly concave or convex utility functions U in a family of increasing functions satisfying certain conditions, where Z is a geometric Brownian motion and T is the time of the nth jump of a Poisson process independent of Z. We obtain some properties of $V$ and offer solutions for the optimal strategies to follow. This provides us with a technique to build numerical approximations of stopping boundaries for the fixed terminal time optimal stopping problem presented in [J. Du Toit and G. Peskir, Ann. Appl. Probab., 19 (2009), pp. 983--1014]

The reliability of physical examination in diagnosing arterial injury in penetrating trauma to extremities: A first look at different anatomical regions and injury mechanisms

Background. The accuracy of physical examination to exclude arterial injury in penetrating trauma to extremities has been well established.Objectives. To determine whether the accuracy of physical examination to exclude arterial injury is similar to that of a computed tomography arteriogram (CTA) for different anatomical regions and mechanisms of injury, and in patients with concomitant fractures compared with those without.Methods. A retrospective review was conducted on all patients who underwent CTA for penetrating injuries to an extremity between 1 June 2016 and 30 June 2017. The presence of arterial injuries was noted, and these were grouped into anatomical areas. Clinical notes were reviewed for the presence of hard signs of arterial injury at initial examination.Results. A total of 220 lower limb and 133 upper limb CTAs were included. The mean patient age was 28.9 years (range 11 - 68). The overall sensitivity of physical examination in detecting a CTA-confirmed arterial injury was 95.3% (95% confidence interval (CI) 88.4 - 98.7), with a specificity of 93.9% (95% CI 90.2 - 96.4). Physical examination of the thigh had the highest specificity of 96.4% (95% CI 91.8 - 98.8), followed by the lower leg at 94.4% (95% CI 81.3 - 99.3), the upper arm at 89.6% (95% CI 79.7 - 95.7) and the forearm at 77.8% (95% CI 40.0 - 97.2). For gunshot wounds the specificity was 96.1% (95% CI 92.4 - 98.3), while for stab wounds it was 86.8% (95% CI 74.7 - 94.5).Conclusions. This study agrees with current literature indicating that physical examination has high specificity in detecting arterial injury in the setting of penetrating trauma to an extremity. However, it shows that the specificity is not equal for all anatomical regions or mechanisms of injury

The genetic relatedness of E. coli associated with post- collection drinking water contamination in rural households

Rural households are often dependent on rivers, springs, boreholes or standpipes some distance from their homes for their daily water requirements. Water for drinking and domestic use is consequently stored in containers in-house which are prone to post-collection contamination. The objective of the study was to determine the most likely origin or place of introduction of E. coli associated with post-collection contamination in rural households, by assessing the degree of genetic relatedness of E. coli present in the stored water and other environmental samples. E. coli isolates were obtained using either mFC agar with confirmation of indole production (44 isolates) or Colilert®-18 (52 isolates). Amplified fragment length polymorphism (AFLP) fingerprinting was applied to determine the genetic relatedness of E. coli isolated from in-house storage containers, drinking cups, hand-swab samples, cattle dung and from the source water (spring water). DNA fingerprints of E. coli produced a number of clusters (>85% similarity scores calculated with the cosine coefficient). Identical E. coli genetic patterns were observed at closely linked points within the domestic pathway of water handling, such as between hand-swab and drinking-cup samples, between storage container and source isolates, and between drinking cups, source water and storage containers. The results indicated that AFLP fingerprinting could be applied to determine the genetic relatedness of E. coli isolated from closely linked points within the domestic pathway of water use within a household. However, the high genetic diversity observed for E. coli bacteria isolated from the difffferent water and environmental samples tested in this study, hampered the identification of post collection points of contamination.Keywords: typing, fingerprinting, amplified fragment length polymorphism, E. coli, water quality, genetic relatedness, AFL

Is questioning consumers about their behavioural intentions useful? Answers from a study of members of an organic produce basket system

After the success of the Amap (French associations to support local small farmer) since the early 2000s in France, many different, less-binding derivatives of this short food supply model have recently appeared. These different basket systems must all grapple with the same problem, namely, the ability to foresee the number of members in the years to come. From a marketing point of view, these systems consequently all share the same concern, that of retaining their member consumers. The case on which the present research is based, Les Paniers Bio Solidaires, concerns precisely this problem of member retention. A database was created from an annual survey (from 2011 to 2016) of the PBS scheme members, to explore this question. This paper presents the results of the exploratory analyses (PCA), followed by their confirmation (by PLS Path Modeling).  We discuss these results and suggest searching for explanations in the area of commitment theories in social psychology

AgapeZ1: a Large Amplification Microlensing Event or an Odd Variable Star Towards the Inner Bulge of M31

AgapeZ1 is the brightest and the shortest duration microlensing candidate event found in the Agape data. It occured only 42" from the center of M31. Our photometry shows that the half intensity duration of the event6 is 4.8 days and at maximum brightness we measure a stellar magnitude of R=18.0 with B-R=0.80 mag color. A search on HST archives produced a single resolved star within the projected event position error box. Its magnitude is R=22.Comment: 4 pages with 5 figure

Investigating the fitness of sea turtles nesting in South Africa

The South African rookeries of the South Western Indian Ocean (SWIO) loggerhead and leatherback regional management units have been continuously monitored for more than 5 decades, representing one of the longest-running sea turtle beach protection and monitoring programmes in the world. Although such conservation has been successful in protecting adults on land when they come to nest, it might not be enough to ensure population recovery if survival is not ensured across all life stages. Sea turtles are particularly vulnerable to direct threats and changing environmental conditions because they are long-lived, slow maturing, and have low survival rates at early life stages, making them conservation-dependent. These characteristics also render them difficult to conserve as a consequence of their wide geographic distributions, spanning multiple jurisdictions and legislative systems with different conservation targets, and a complex life cycle with changes in habitats and diets at different life stages. Sea turtle populations have been severely depleted as a result of historical over-exploitation and current threats including fisheries bycatch, direct harvest, habitat loss, pollution and pathogens, and climate change. In many cases however, population declines have been reversed by a variety of effective conservation measures such as beach protection programs, and marine protected areas, enabling successful population recovery around the world. Despite protection and apparent increase in abundance, indirect pressures can still affect turtle populations. Therefore, it is fundamental to evaluate the effectiveness of conservation measures (using fitness traits such as female and hatchling sizes) and examine underlying trends. The aim of this thesis was thus to evaluate the fitness of loggerhead and leatherback sea turtles nesting in South Africa. Long-term female size trends over time were evaluated and the populations were split between first-time nesters and experienced nesters. As sea turtle reproductive output (clutch size only) is correlated with female size and evidence is showing that in some populations individual female size is decreasing, the effects of maternal body size on reproductive output and hatchling fitness were investigated for both species. Crawling and swimming speeds were used as proxies of hatchling fitness, because these two traits positively influence their survival. An oceanic model was further used in combination with a particle tracking framework to estimate, for the first time, post-hatchling dispersal of loggerhead and leatherback turtles in the SWIO. I investigated whether the trend in female size for loggerhead turtles nesting in South Africa is a result of their foraging strategy to determine if there is a foraging dichotomy (neritic and oceanic). Despite an apparent increasing population, a significant 3.7 and 3.6 cm decrease in the size of both recruit and remingrant female loggerhead turtles, but a stable mean size of leatherbacks for both age groups was observed. I hypothesise that these contradictory effects are attributable to the very distinct foraging ecologies of the two turtle species and speculate that these variations in carapace length may be driven by environmental change. The reproductive strategy of both loggerhead and leatherback turtles nesting in South Africa supports the optimal egg size theory with larger turtles producing larger clutches but not larger eggs. Egg size was thus constant irrespective of maternal length. Hatchlings with longer carapaces and flippers had higher swimming speed, suggesting that larger hatchlings are fitter (potentially higher survival) than smaller ones by spending less time in high predation risk areas (i.e. beach and nearshore). The model revealed that dispersal trajectories of both loggerhead and leatherback sea turtle hatchlings were very similar and simulations indicated that initial active swimming (frenzy) as well as variability in oceanic conditions strongly influenced dispersal of virtual hatchlings. The trends observed in this study emphasize the importance of long-term monitoring, examining not only abundance but also individual size, to understand population dynamics, support recovery planning and prioritize future conservation practices. Furthermore, the findings of this study have important implications for overall population growth if smaller hatchlings of lower fitness are produced as a result of climate change and thus have decreased dispersal abilities and lower likelihood of survival

Supersymmetry of the Schrodinger and PP Wave Solutions in Einstein-Weyl Supergravities

We obtain the Schrodinger and general pp-wave solutions with or without the massive vector in Einstein-Weyl supergravity. The vector is an auxiliary field in the off-shell supermultiplet and it acquires a kinetic term in the Weyl-squared super invariant. We study the supersymmetry of these solutions and find that turning on the massive vector has a consequence of breaking all the supersymmetry. The Schrodinger and also the pp-wave solutions with the massive vector turned off on the other hand preserve 1/4 of the supersymmetry.Comment: 13 pages, no figur