A Methodology to Improve the Proactive Mitigation of Helicopter Accidents Related to Loss of Tail Rotor Effectiveness

Loss of tail rotor effectiveness (LTE) has been recognized to be a major contributing factor in several helicopter accidents where pilots lost directional control. However, it has been noticed that different definitions of this phenomenon exist in the rotorcraft community. Further, the somewhat imprecise representation of LTE in some flight training simulators has led to its low awareness, placing pilots at a much higher risk for potential accidents. One significant method to specifically address those gaps and support rotorcraft safety involves the proactive mitigation of LTE via the analysis of flight data within the Helicopter Flight Data Monitoring (HFDM) program. Through this program, the pilots receive constant flight evaluation reports to promote improved LTE risk evaluations. The main method used for flight data analysis is the detection of safety metrics, i.e., predefined hazardous flight conditions. Nevertheless, a sufficiently reliable LTE safety metric still does not exist, leading to false or missed detections that degrade the quality of the overall safety analysis. The objective of this thesis is to formulate a methodology to enhance the detection capability of the proximity to LTE within the HFDM program. This promotes the awareness of LTE within the rotorcraft community while supporting the proactive mitigation of helicopter accidents related to this critical helicopter safety threat. An alternative approach is used to develop a more reliable LTE safety metric, using a combination of physics-based simulations and machine learning techniques. First, a physics-based investigation is performed to enhance the understanding of the nature of the LTE. A more comprehensive LTE definition is proposed and analyzed, including three different aspects that can lead to LTE behavior, i.e., loss of weathercock stability, running out of pedal (tail rotor collective) for trim, and tail rotor vortex ring state. The modeling of the flight dynamics of each phenomenon is individually analyzed to ensure an accurate physics-based representation of LTE. Further, the parameters that support the detection of LTE are investigated to enable the recognition and classification of each LTE phenomenon in simulation results. Ultimately, a physics-based investigation of the aircraft flight envelope is combined with the application of supervised learning techniques to develop the predictive models of the different LTE phenomena. This provides the operator with a physics-based LTE safety metric designed to detect the proximity to LTE without the need for a simulation model. The methodology is implemented using a generic nonlinear helicopter simulation model. To verify the enhanced capabilities of the final methodology, the physics-based LTE safety metric is compared against the LTE metric currently used within the HFDM program. The results confirm the improved detection of the proximity to LTE, validating the overarching hypothesis of this research and satisfying the research objective.Ph.D

Pyruvate kinase deficiency

Over the past few years the inherited disorders of erythrocyte metabolism have been the object of intensive research which has resulted in a better understanding of their molecular basis. However, curative therapy for red blood cell (RBC) enzyme defects still remains undeveloped. Among glycolyti

A thorough analysis of the occurrence, removal and environmental risks of organic micropollutants in a full-scale hybrid membrane bioreactor fed by hospital wastewater

The recent draft of the Urban Wastewater Treatment Directive pays attention to contaminants of emerging concern including organic micropollutants (OMPs) and requires the removal of some of them at large urban wastewater treatment plants (WWTPs) calling for their upgrading. Many investigations to date have reported the occurrence of a vast group of OMPs in the raw influent and many technologies have been tested for their removal at a lab- or pilot-scale. Moreover, hospital wastewater (HWW) may contain specific OMPs at a high concentration and therefore its treatment deserves attention. In this study, a 1-year investigation was carried out at a full-scale membrane bioreactor (MBR) treating mainly HWW. To promote the removal of OMPs, powdered activated carbon (PAC) was added to the bioreactor at 0.1 g/L and 0.2 g/L which resulted in the MBR operating as a hybrid MBR. Its performance was tested for 232 target and 90 non-target OMPs, analysed by UHPLC-QTOF-MS using a direct injection method. The wastewater arriving at the WWTP was characterized and the performance of both the MBR and hybrid MBR was assessed for: key OMPs selected on the basis of their frequency, occurrence, persistence to removal, bioaccumulation and toxicity; OMP classes; and the whole list of OMPs. Finally, an environmental risk assessment of the OMP residues was conducted by means of the risk quotient approach. The results indicate that PAC addition increased the removal of most of the key OMPs (e.g., sulfamethoxazole, diclofenac, lidocaine) and OMP classes (e.g., antibiotics, psychiatric drugs and stimulants) with the highest loads in the WWTP influent. The hybrid MBR also reduced the risk in the receiving water as the PAC dosage increased mainly for spiramycin, lorazepam, oleandomycin. Finally, uncertainties and issues related to the investigation being carried out at full-scale under real conditions are discussed in depth

The impact of antiretroviral therapy on iron homeostasis and inflammation markers in HIV-infected patients with mild anemia

BACKGROUND: Anemia is frequent during HIV infection and is predictive of mortality. Although cART has demonstrated to reduce its prevalence, several patients still experience unresolved anemia. We aimed to characterize iron homeostasis and inflammation in HIV-infected individuals with mild anemia in relation to cART. METHODS: In this retrospective cohort study, HIV-infected patients with mild anemia, CD4+ cells > 200/mm3 at baseline, maintaining virological response for 12 months after cART starting were selected within the Standardized Management of Antiretroviral Therapy Cohort (MASTER) cohort. Several inflammation and immune activation markers and iron homeostasis indexes were measured in stored samples, obtained at cART initiation (T0) and 12 months later (T1). Patients were grouped on the basis of hemoglobin values at T1: group A (> 13 g/dl) and B (< 13 g/dl). Wilcoxon rank sum test was used to compare biomarker values. Pearson correlation coefficients were calculated for all variables. RESULTS: cART improved CD4+ and CD8+ cell counts and their ratio, but this effect was significant only in group A. Only these patients had mild iron deficiency at T0 and showed higher transferrin and lower percentage of transferrin saturation than patients of group B, but differences disappeared with cART. cART decreased inflammation in all patients, but group B had higher levels of all markers than group A, reaching statistical significance only for IL-8 values at T1 (16 vs 2.9 pg/ml; p = 0.017). Hepcidin and IL-6 levels did not show significant differences between groups. Hemoglobin levels both at T0 and T1 did not correlate with any marker. CONCLUSIONS: Baseline mild anemia in HIV-infected patients cannot always be resolved with durable efficient cART, possibly due to residual inflammation or immune activation rather than unbalanced iron homeostasis. Further research is needed on cytokine profiling to understand the mechanisms that induce anemia in HIV with suppressive cART

Structure and Function of Human Erythrocyte Pyruvate Kinase MOLECULAR BASIS OF NONSPHEROCYTIC HEMOLYTIC ANEMIA

Deficiency of human erythrocyte isozyme (RPK) is, together with glucose-6-phosphate dehydrogenase deficiency, the most common cause of the nonspherocytic hemolytic anemia. To provide a molecular framework to the disease, we have solved the 2.7 A resolution crystal structure of human RPK in complex with fructose 1,6-bisphosphate, the allosteric activator, and phosphoglycolate, a substrate analogue, and we have functionally and structurally characterized eight mutants (G332S, G364D, T384M, D390N, R479H, R486W, R504L, and R532W) found in RPK-deficient patients. The mutations target distinct regions of RPK structure, including domain interfaces and catalytic and allosteric sites. The mutations affect to a different extent thermostability, catalytic efficiency, and regulatory properties. These studies are the first to correlate the clinical symptoms with the molecular properties of the mutant enzymes. Mutations greatly impairing thermostability and/or activity are associated with severe anemia. Some mutant proteins exhibit moderate changes in the kinetic parameters, which are sufficient to cause mild to severe anemia, underlining the crucial role of RPK for erythrocyte metabolism. Prediction of the effects of mutations is difficult because there is no relation between the nature and location of the replaced amino acid and the type of molecular perturbation. Characterization of mutant proteins may serve as a valuable tool to assist with diagnosis and genetic counseling

Soil, humipedon, forest life and management

In recent years, three sections (Humipedon, Copedon and Lithopedon) were recognized in the soil profile. It was then possible to link the first and most biologically active section to the characteristics of the environment and soil genesis. In particular, it is now possible to distinguish organic horizons, mainly produced by arthropods and enchytraeids in cold and acidic or dry and arid environments, from organo-mineral horizons produced by earthworms in more temperate and mesotrophic environments. Each set of horizons can be associated with a humus system or form, with important implications for forestry. Anecic/endogeic earthworms and Mull or Amphi systems are more abundant in the early and late stages of sylvogenesis; by completely recycling litter, earthworms accelerate the availability of organic and inorganic soil nutrients to roots and pedofauna. On the other hand, arthropods and Moder or Tangel systems characterize the intermediate stages of sylvogenesis, where thickening in the organic horizons and the parallel impoverishment/reduction in the underlying organo-mineral horizons are observed. Recognizing the humus system at the right spatial and temporal scale is crucial for the biological management of a forest. This article includes a data review, new data from a doctoral thesis, and recent comparisons of Italian and French investigation

West Nile virus transmission. results from the integrated surveillance system in Italy, 2008 to 2015

IIn Italy a national Plan for the surveillance of imported and autochthonous human vector-borne diseases (chikungunya, dengue, Zika virus disease and West Nile virus (WNV) disease) that integrates human and veterinary (animals and vectors) surveillance, is issued and revised annually according with the observed epidemiological changes. Here we describe results of the WNV integrated veterinary and human surveillance systems in Italy from 2008 to 2015. A real time data exchange protocol is in place between the surveillance systems to rapidly identify occurrence of human and animal cases and to define and update the map of affected areas i.e. provinces during the vector activity period from June to October. WNV continues to cause severe illnesses in Italy during every transmission season, albeit cases are sporadic and the epidemiology varies by virus lineage and geographic area. The integration of surveillance activities and a multidisciplinary approach made it possible and have been fundamental in supporting implementation of and/or strengthening preventive measures aimed at reducing the risk of transmission of WNV trough blood, tissues and organ donation and to implementing further measures for vector control

Relações de gênero no trabalho em saúde em um estabelecimento prisional feminino

O objetivo do artigo é discutir sobre as relações de gênero na perspectiva de profissionais de uma Equipe de Atenção Básica Prisional (EABp) de uma penitenciária feminina. Os dados foram produzidos a partir da fala de profissionais da saúde em cinco encontros de apoio matricial e o gênero foi utilizado como categoria de análise. Como resultados, foi possível organizar três subtemas como desdobramentos do tema principal: gestação e permanência dos bebês na prisão; normas corporais e saúde; e, nome social de pessoas trans. A discussão segue referenciais dos estudos de diversidade sexual e de gênero e saúde coletiva e aborda a necessidade do direito à saúde integral da população encarcerada e, especificamente, de mulheres e população LGBTI. A centralidade do cuidado relativo à gestação e o papel da educação permanente para a redução do preconceito e qualificação no atendimento, também aparecem como campos de trabalho a ser explorados