136 research outputs found

    Optimizing the Use of the United States Army OH-58D Helicopter Simulator and Aircraft for Full-Authority Digital Electronic Control Manual Throttle Training

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    Over the past decade the United States Army has used a Full-Authority Digital Electronic Control (FADEC) system to control fuel flow to the engine of the OH-58D helicopter. Currently, part of the training is primarily conducted for the scenario of a FADEC system failure in the aircraft. Because of the complexity of this task, a number of accidents have occurred resulting in minor to severe damage to the aircraft. The United States Army has recently fielded two OH-58D Operational Flight Training Simulators in an effort to increase training efficiency and effectiveness. It is anticipated that the simulators will provide a safer environment and an effected transfer of training to the aircraft. Currently the OH-58D training unit has implemented the simulator into the manual throttle stage of training. This implementation has occurred through verification and validation of the Program of Instruction (POI) currently in use. An investigation into the transfer of training from the simulator to the aircraft was conducted to further optimize the distributions of training time in the simulator versus the aircraft. The primary source of data was collected from aircraft and simulator trials and flight hours to evaluate the transfer effectiveness ratio. The secondary source of data was collected through the use of pilot surveys and questionnaires. The pilots reported a mean workload rating of 2.52 using the Bedford Workload Rating Scale in the aircraft after the simulator, which indicates a low workload. The Pilots reported mild to moderate simulator sickness symptoms after flying in the simulator. A total severity score of 20.06 was computed through the use of the Simulator Sickness Questionnaire. When compared to other helicopter simulators this score is fairly high. Overall there were low Pilot-Vehicle Interface problems in the simulator and aircraft. There was no decline in Situational Awareness from the simulator to the aircraft. The overall Transfer Effectiveness Ratios indicated a positive Transfer of Training. The current Program of Instruction and simulator hours are validated. The focus in the simulator should be placed on Method of Instructions step two “failure at a hover” and step four “running landing or approach to a hover.

    Regulation of the reproductive cycle and early pregnancy by relaxin family peptides

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    The relaxin family of peptide hormones are structurally closely related to one another sharing a heterodimeric A–B structure, like that of insulin. They may also be active as unprocessed B–C–A pro-forms. Relaxin has been shown to pay a key role within the ovary, being involved in follicle growth, and ovulation. Relaxin is produced in large amounts also by the corpus luteum where it acts as an endocrine hormone positively affecting implantation, placentation and vascularization during the all-important first trimester phase of pregnancy establishment. Relaxin exerts its functions via the receptor RXFP1. Insulin-like peptide 3 (INSL3) in contrast acts through the related receptor RXFP2, and plays an essential role in the production of androgens within growing antral follicles. INSL3 is also produced in large amounts by the male fetus shortly after sex determination, where it controls the first transabdominal phase of testicular descent. However, this fetal INSL3 is also able to influence placental and maternal physiology, indicating associations with later preeclampsia and/or fetal growth restriction. Other members of this relaxin-like family of peptides, such as INSL4, INSL5 and INSL6 are less well studied, though all suggest modulatory roles in ovarian and/or placental function

    Relevance of Stress and Female Sex Hormones for Emotion and Cognition

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    There are clear sex differences in incidence and onset of stress-related and other psychiatric disorders in humans. Yet, rodent models for psychiatric disorders are predominantly based on male animals. The strongest argument for not using female rodents is their estrous cycle and the fluctuating sex hormones per phase which multiplies the number of animals to be tested. Here, we will discuss studies focused on sex differences in emotionality and cognitive abilities in experimental conditions with and without stress. First, female sex hormones such as estrogens and progesterone affect emotions and cognition, contributing to sex differences in behavior. Second, females respond differently to stress than males which might be related to the phase of the estrous cycle. For example, female rats and mice express less anxiety than males in a novel environment. Proestrus females are less anxious than females in the other estrous phases. Third, males perform in spatial tasks superior to females. However, while stress impairs spatial memory in males, females improve their spatial abilities, depending on the task and kind of stressor. We conclude that the differences in emotion, cognition and responses to stress between males and females over the different phases of the estrous cycle should be used in animal models for stress-related psychiatric disorders

    Helminth immunomodulation in autoimmune disease

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    Helminths have evolved to become experts at subverting immune surveillance. Through potent and persistent immune tempering, helminths can remain undetected in human tissues for decades. Redirecting the immunomodulating "talents" of helminths to treat inflammatory human diseases is receiving intensive interest. Here, we review therapies using live parasitic worms, worm secretions, and worm-derived synthetic molecules to treat autoimmune disease. We review helminth therapy in both mouse models and clinical trials and discuss what is known on mechanisms of action. We also highlight current progress in characterizing promising new immunomodulatory molecules found in excretory/secretory products of helminths and their potential use as immunotherapies for acute and chronic inflammatory diseases

    Neohormones as biomarkers of reproductive health

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    Neohormone systems are defined as evolutionarily new endocrine or paracrine adaptations that supplement basic physiologic functions and define mammalian success. The relaxin family of peptide hormones are typical neohormones. Because they define the specific mammalian aspects of reproductive physiology, such as viviparity with implantation and placentation, lactation, or in the male the necessary adaptations to sperm needed for successful internal fertilization, they offer excellent biomarkers for characterizing reproductive health and disease. For example, ovarian H2-relaxin aids implantation and the establishment of the placenta, and circulating levels are significantly altered in early miscarriage. In the fetus, testicular INSL3 is responsible for the first phase of testicular descent and may be disrupted in cryptorchidism. In the adult, INSL3 is believed to be involved as an antiapoptotic factor in germ cell survival (male) and follicle selection (female) and acts as an excellent measure of Leydig cell functional capacity, particularly in the aging male. INSL5 and INSL6 appear also to be involved in the maintenance of adequate spermatogenesis. With the development of robust immunoassays for various relaxin family members, we are progressively gathering baseline information about normal biomarker levels as well as their perturbations in a wide range of reproductive pathologies

    Edible films and coatings as carriers of living microorganisms: a new strategy towards biopreservation and healthier foods

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    Edible films and coatings have been extensively studied in recent years due to their unique properties and advantages over more traditional conservation techniques. Edible films and coatings improve shelf life and food quality, by providing a protective barrier against physical and mechanical damage, and by creating a controlled atmosphere and acting as a semipermeable barrier for gases, vapor, and water. Edible films and coatings are produced using naturally derived materials, such as polysaccharides, proteins, and lipids, or a mixture of these materials. These films and coatings also offer the possibility of incorporating different functional ingredients such as nutraceuticals, antioxidants, antimicrobials, flavoring, and coloring agents. Films and coatings are also able to incorporate living microorganisms. In the last decade, several works reported the incorporation of bacteria to confer probiotic or antimicrobial properties to these films and coatings. The incorporation of probiotic bacteria in films and coatings allows them to reach the consumers gut in adequate amounts to confer health benefits to the host, thus creating an added value to the food product. Also, other microorganisms, either bacteria or yeast, can be incorporated into edible films in a biocontrol approach to extend the shelf life of food products. The incorporation of yeasts in films and coatings has been suggested primarily for the control of the postharvest disease. This work provides a comprehensive review of the use of edible films and coatings for the incorporation of living microorganisms, aiming at the biopreservation and probiotic ability of food products.Ana Guimaraes received support through grant SFRH/BD/ 103245/2014 from the Portuguese Foundation for Science and Technology (FCT). Luís Abrunhosa was supported by grant UMINHO/BPD/51/2015 from project UID/BIO/04469/2013 financed by FCT/MEC (OE). This study was supported by FCT under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), and of BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Vectors used in Figure were designed by Freepik.info:eu-repo/semantics/publishedVersio

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