Accuracy between prehospital and hospital diagnosis in helicopter emergency medical services and its consequences for trauma care

PURPOSE For optimal prehospital trauma care, it is essential to adequately recognize potential life-threatening injuries in order to correctly triage patients and to initiate life-saving measures. The aim of the present study was to determine the accuracy of prehospital diagnoses suspected by helicopter emergency medical services (HEMS). METHODS This retrospective multicenter study included patients from the Swiss Trauma Registry with ISS ≥ 16 or AIS head ≥ 3 transported by Switzerland's largest HEMS and subsequently admitted to one of twelve Swiss trauma centers from 01/2020 to 12/2020. The primary outcome was the comparison of injuries suspected prehospital with the final diagnoses obtained at the hospital using the abbreviated injury scale (AIS) per body region. As secondary outcomes, prehospital interventions were compared to corresponding relevant diagnoses. RESULTS Relevant head trauma was the most commonly injured body region and was identified in 96.3% (95% CI: 92.1%; 98.6%) of the cases prehospital. Relevant injuries to the chest, abdomen, and pelvis were also common but less often identified prehospital [62.7% (95% CI: 54.2%; 70.6%), 45.5% (95% CI: 30.4%; 61.2%), and 61.5% (95% CI: 44.6%; 76.6%)]. Overall, 7 of 95 (7.4%) patients with pneumothorax received a chest decompression and in 22 of 39 (56.4%) patients with an instable pelvic fracture a pelvic binder was applied prehospital. CONCLUSION Approximately half of severe chest, abdominal, and pelvic diagnoses made in hospital went undetected in the challenging prehospital environment. This underlines the difficult circumstances faced by the rescue teams. Potentially life-saving interventions such as prehospital chest decompression and increased use of a pelvic binder were identified as potential improvements to prehospital care

Feed intake and performance of Hubbard Flex broilers with varying dietary energy and protein concentrations

Broiler breeding companies continue to analyse the recommended nutrient levels of broiler diets due to the short production cycle and continuous genetic development of broilers. Modern broilers reach marketable weights very early, often at an immature body weight and without achieving maximum genetic potential in terms of absolute quantities, for example daily growth. As broilers age, their daily feed intake increases and nutrients are deposited in body tissue, mainly as protein and fat. An imbalance of energy or protein cause for excess fat deposited in carcasses due to excessive feed intake to satisfy a nutritional requirement. The cost of feed contributes substantially to the total production expenses, with energy alone contributing approximately 70% of the total cost of poultry diets. Therefore, the focus of feed companies remain to determine the energy and protein requirements of broilers, in order to feed a balanced diet, delivering a bird with an optimal carcass composition. Two experiments of identical design were conducted in floor pens to evaluate the effect of metabolisable energy levels as well as crude protein levels on broiler performance. The first trial was an energy dose-response trial and the second trial a protein dose-response trial. Each study was conducted over a period of five weeks where five thousand seven hundred and sixty Hubbard Flex (mixed sex as hatched) broilers were housed in 60 pens. Ninety six (96) chicks were randomly allocated in a pen at a stocking density of 16 birds/m2. Each treatment was repeated once within a block, totalling to 10 replications/treatment. Water and feed were provided ad libitum. In the energy dose-response experiment two iso-protein basal feeds were formulated and manufactured, one containing a high energy (HE) level, the other a low energy (LE) level. These basal diets were further diluted into four diets containing various percentages of energy (80% LE: 20% HE; 60% LE: 40% HE; 40% LE: 60% HE and 20% LE: 80% HE). The crude protein and amino acid balance was kept constant across all treatments. Six dietary treatment combinations were implemented in a 4-phase feeding programme: Pre-starter (0 to 10 d), Starter (11 to 18 d), Grower (19 to 28 d) and Finisher (29 to 35 d of age). Body weight (BW) and average daily gain did not show any significant difference between LE and HE treatments. A weekly numerical difference was recorded for BW between LE and HE treatments; where birds fed the HE diet weighed heavier on Day 35, at 1939.97 g compared to the 1898.10 g of birds fed the LE diet. FI increased as the energy concentration increased from the LE to HE treatments; and although the differences in FI was non-significant (NS), birds fed HE diets consumed 2882.11 g/bird by Day 35 and birds fed LE diets, only consumed 2830.90 g/bird in total. No significant difference was recorded for cumulative feed conversion ratio (CFCR) among treatments by Day 35 and birds fed the LE diet ended with 1.53 points compared to 1.52 points for birds fed HE diet. Despite the dietary energy increase in energy level from the LE diet to the HE diet, there was no significant effect on daily mortalities; birds fed the LE diet showed 5.10% mortality compared to 5.41% mortality for birds fed the HE diet. In the protein dose-response trial two isocaloric basal feeds were formulated and manufactured, one containing a high protein (HP) level, the other a low protein (LP) level. These basal diets were further diluted into 4 diets containing various percentages of protein (80% LP: 20% HP, 60% LP: 40% HP, 40% LP: 60% HP and 20% LP: 80% HP). The dietary metabolisable energy (ME) was kept constant across all treatments. Birds fed the HP diet showed the greatest BW at Day 21 with 900.97 g compared to birds fed the LP diet on 858.85 g; and weighed 1937.48 g at Day 35 compared to 1869.80 g for birds fed LP diet. Cumulative feed intake (CFI) decreased as the protein content in the feed increased. Although the results from Day 28 only approached significance, birds fed the HP diet consumed significantly less feed (2840.29 g/bird) than birds fed the LP diet (2913.66 g/bird) by Day 35. CFCR for HP was 1.50 points by Day 35 compared to 1.59 points for LP. The increase in protein content from LP to the HP diet, did not cause a significant increase in mortalities; although a numerical increase can be seen of 6.24% for birds fed on the LP diet compared to 9.06% mortality in birds fed the HP diet.Dissertation (MSc)--University of Pretoria, 2015.Animal and Wildlife SciencesMScUnrestricte

Study of proliferation of Acanthamoeba castellanii upon infection by Legionella pneumophila

Acanthamoeba castellanii est une amibe libre ubiquiste de l'environnement. Elle se nourrit principalement de micro-organismes par phagocytose. Seulement, certains micro-organismes ont développé des mécanismes de résistances qui leur permettent d'échapper à la digestion et même de se multiplier à l'intérieur des amibes. C'est le cas de Legionella pneumophila, bactérie responsable de la légionellose. Legionella pneumophila, à travers son système de sécrétion Dot/Icm, injecte plusieurs effecteurs à l'intérieur de son hôte. Ces effecteurs interagissent avec les protéines de l'hôte, et induisent une modification de la physiologie de son hôte, à son avantage. Durant ma thèse, nous nous sommes intéressés aux effets de Legionella pneumophila, sur la prolifération de son hôte amibien. Nous avons montré que Legionella pneumophila arrête la prolifération d'Acanthamoeba castellanii. Ce phénotype était associé une modification de la forme, à une perte d'adhérence et à une baisse de motilité de l'amibe. Sur le plan moléculaire, Legionella pneumophila induit une baisse dans l'expression du gène cdc2b, qui présente des similarités avec le gène cdk1 (cyclin dépendant kinase), codant pour la CDK essentielle au déroulement du cycle cellulaire chez les mammifères. L'arrêt de la prolifération d'Acanthamoeba castellanii, qui passe par une réduction d'expression de cdc2b, est certainement induit par un ou plusieurs effecteur(s) de Legionella pneumophila, car le mutant ΔdotA de L. pneumophila, défectueux au niveau de l'appareil de sécrétion Dot/Icm, n'induit pas l'arrêt de la prolifération d'Acanthamoeba castellanii.Acanthamoeba castellanii is an ubiquitous free-living amoeba of the environment. This amoeba feeds mainly on micro-organisms by phagocytosis. However, some micro-organisms have acquired resistances that allow them to escape digestion and even multiply inside amoebae. This is the case of Legionella pneumophila, the bacterium responsible for legionellosis. Legionella pneumophila, through its Dot/Icm secretion system, injects several effectors into its host. These effectors interact with the proteins of the host, and induce a modification of the physiology of its host, to its advantage. During my phD, we were interested in the effects of Legionella pneumophila infection on the proliferation of its amoebic host. We showed that Legionella pneumophila prevents the proliferation of Acanthamoeba castellanii. This phenotype was associated with a modification of the shape, a loss of adhesion and a decrease in motility of the amoeba. On the molecular level, Legionella pneumophila induces a decrease in the expression of the cdc2b gene, which share similarities with the cdk1 (cyclin dependent kinase) gene, coding for the major CDK of the mammalian cells cycle. The arrest of proliferation of Acanthamoeba castellanii, which involves a reduction in expression of cdc2b, is certainly induced by one or more effector(s) of Legionella pneumophila, because the mutant ΔdotA of L. pneumophila, defective in the Dot/Icm secretion apparatus, does not induce proliferation arrest of Acanthamoeba castellanii

OPriv: Optimizing Privacy Protection for Network Traffic

Statistical traffic analysis has absolutely exposed the privacy of supposedly secure network traffic, proving that encryption is not effective anymore. In this work, we present an optimal countermeasure to prevent an adversary from inferring users’ online activities, using traffic analysis. First, we formulate analytically a constrained optimization problem to maximize network traffic obfuscation while minimizing overhead costs. Then, we provide OPriv, a practical and efficient algorithm to solve dynamically the non-linear programming (NLP) problem, using Cplex optimization. Our heuristic algorithm selects target applications to mutate to and the corresponding packet length, and subsequently decreases the security risks of statistical traffic analysis attacks. Furthermore, we develop an analytical model to measure the obfuscation system’s resilience to traffic analysis attacks. We suggest information theoretic metrics for quantitative privacy measurement, using entropy. The full privacy protection of OPriv is assessed through our new metrics, and then through extensive simulations on real-world data traces. We show that our algorithm achieves strong privacy protection in terms of traffic flow information without impacting the network performance. We are able to reduce the accuracy of a classifier from 91.1% to 1.42% with only 0.17% padding overhead

Étude de la prolifération d'Acanthamoeba castellanii suite à l'infection par Legionella pneumophila

Acanthamoeba castellanii is an ubiquitous free-living amoeba of the environment. This amoeba feeds mainly on micro-organisms by phagocytosis. However, some micro-organisms have acquired resistances that allow them to escape digestion and even multiply inside amoebae. This is the case of Legionella pneumophila, the bacterium responsible for legionellosis. Legionella pneumophila, through its Dot/Icm secretion system, injects several effectors into its host. These effectors interact with the proteins of the host, and induce a modification of the physiology of its host, to its advantage. During my phD, we were interested in the effects of Legionella pneumophila infection on the proliferation of its amoebic host. We showed that Legionella pneumophila prevents the proliferation of Acanthamoeba castellanii. This phenotype was associated with a modification of the shape, a loss of adhesion and a decrease in motility of the amoeba. On the molecular level, Legionella pneumophila induces a decrease in the expression of the cdc2b gene, which share similarities with the cdk1 (cyclin dependent kinase) gene, coding for the major CDK of the mammalian cells cycle. The arrest of proliferation of Acanthamoeba castellanii, which involves a reduction in expression of cdc2b, is certainly induced by one or more effector(s) of Legionella pneumophila, because the mutant ΔdotA of L. pneumophila, defective in the Dot/Icm secretion apparatus, does not induce proliferation arrest of Acanthamoeba castellanii.Acanthamoeba castellanii est une amibe libre ubiquiste de l'environnement. Elle se nourrit principalement de micro-organismes par phagocytose. Seulement, certains micro-organismes ont développé des mécanismes de résistances qui leur permettent d'échapper à la digestion et même de se multiplier à l'intérieur des amibes. C'est le cas de Legionella pneumophila, bactérie responsable de la légionellose. Legionella pneumophila, à travers son système de sécrétion Dot/Icm, injecte plusieurs effecteurs à l'intérieur de son hôte. Ces effecteurs interagissent avec les protéines de l'hôte, et induisent une modification de la physiologie de son hôte, à son avantage. Durant ma thèse, nous nous sommes intéressés aux effets de Legionella pneumophila, sur la prolifération de son hôte amibien. Nous avons montré que Legionella pneumophila arrête la prolifération d'Acanthamoeba castellanii. Ce phénotype était associé une modification de la forme, à une perte d'adhérence et à une baisse de motilité de l'amibe. Sur le plan moléculaire, Legionella pneumophila induit une baisse dans l'expression du gène cdc2b, qui présente des similarités avec le gène cdk1 (cyclin dépendant kinase), codant pour la CDK essentielle au déroulement du cycle cellulaire chez les mammifères. L'arrêt de la prolifération d'Acanthamoeba castellanii, qui passe par une réduction d'expression de cdc2b, est certainement induit par un ou plusieurs effecteur(s) de Legionella pneumophila, car le mutant ΔdotA de L. pneumophila, défectueux au niveau de l'appareil de sécrétion Dot/Icm, n'induit pas l'arrêt de la prolifération d'Acanthamoeba castellanii

Accuracy between prehospital and hospital diagnosis in helicopter emergency medical services and its consequences for trauma care.

PURPOSE For optimal prehospital trauma care, it is essential to adequately recognize potential life-threatening injuries in order to correctly triage patients and to initiate life-saving measures. The aim of the present study was to determine the accuracy of prehospital diagnoses suspected by helicopter emergency medical services (HEMS). METHODS This retrospective multicenter study included patients from the Swiss Trauma Registry with ISS ≥ 16 or AIS head ≥ 3 transported by Switzerland's largest HEMS and subsequently admitted to one of twelve Swiss trauma centers from 01/2020 to 12/2020. The primary outcome was the comparison of injuries suspected prehospital with the final diagnoses obtained at the hospital using the abbreviated injury scale (AIS) per body region. As secondary outcomes, prehospital interventions were compared to corresponding relevant diagnoses. RESULTS Relevant head trauma was the most commonly injured body region and was identified in 96.3% (95% CI: 92.1%; 98.6%) of the cases prehospital. Relevant injuries to the chest, abdomen, and pelvis were also common but less often identified prehospital [62.7% (95% CI: 54.2%; 70.6%), 45.5% (95% CI: 30.4%; 61.2%), and 61.5% (95% CI: 44.6%; 76.6%)]. Overall, 7 of 95 (7.4%) patients with pneumothorax received a chest decompression and in 22 of 39 (56.4%) patients with an instable pelvic fracture a pelvic binder was applied prehospital. CONCLUSION Approximately half of severe chest, abdominal, and pelvic diagnoses made in hospital went undetected in the challenging prehospital environment. This underlines the difficult circumstances faced by the rescue teams. Potentially life-saving interventions such as prehospital chest decompression and increased use of a pelvic binder were identified as potential improvements to prehospital care

Engineering Asymmetric Lipid Vesicles: Accurate and Convenient Control of the Outer Leaflet Lipid Composition

The asymmetric distribution of lipids between the two bilayer leaflets represents a typical feature of biological membranes. The loss of this asymmetry, for example the exposure of negatively charged lipids on the extracellular membrane leaflet of mammalian cells, is involved in apoptosis and occurs in tumor cells. Thus, the controlled production of asymmetric liposomes helps to better understand such crucial cellular processes. Here, we present an approach that allows us to design asymmetric model-membrane experiments on a rational basis and predict the fraction of exchanged lipid. In addition, we developed a label-free and nondestructive assay to quantify the asymmetric uptake of negatively charged lipids in terms of the zeta potential. This significantly enhances the applicability, impact, and predictive power of model membranes