5,676 research outputs found

    Factors affecting handling qualities of a lift-fan aircraft during steep terminal area approaches

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    The XV-5B lift-fan aircraft was used to explore the factors affecting handling qualities in the terminal area. A 10 deg ILS approach task was selected to explore these problems. Interception of the glide slope at 457.2 m, glide slope tracking, deceleration along the glide slope to a spot hover were considered. Variations in airplane deck angle, deceleration schedule, and powered-lift management were studied. The overall descent performance envelope was identified on the basis of fan stall, maximum comfortable descent rate, and controllability restrictions. The collective-lift stick provided precise glide slope tracking capability. The pilot preferred a deck-parallel attitude for which he used powered lift to control glide slope and pitch attitude to keep the angle of attack near zero. Workload was reduced when the deceleration schedule was delayed until the aircraft was well established on the glide slope, since thrust vector changes induced flight path disturbances

    Post Traumatic Stress Disorder and Psychological Therapies

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    Literature Review: The current review presents a recent review of the effectiveness of psychological therapies to treat sleep difficulties (such as insomnia and nightmares) in sufferers of posttraumatic stress disorder (PTSD). The review also aimed to investigate whether there are differences in the effectiveness of specific psychological therapies to treat sleep disturbances in PTSD, such as between the different types of psychological therapies such as cognitive behavioural therapy for insomnia (CBT-I) and imagery rehearsal therapy (IRT). Eleven studies were included in the review that met the inclusion and exclusion criteria. Results are presented in tables and a descriptive account is included. The review demonstrates that psychological therapies are effective for the treatment of insomnia and other sleep difficulties such as nightmares. However, firm conclusions cannot be drawn about the effectiveness of different types of psychological therapies as studies predominantly used CBT and only one non-CBT study was included in the review. Comparisons between the effectiveness of different CBT approaches is also not possible as there was a large range of diversity in the study characteristics and also there were only a small number of studies for each intervention, which therefore limits the generalisability of results in the current review. It may be that different CBT interventions such as CBT-I or EERT and IRT may be better suited to treat insomnia and nightmares respectively, but further research needs to be conducted into which of these approaches are beneficial for different PTSD specific sleep difficulties. Empirical Paper: Initial studies demonstrate that self-compassion reduces symptoms of PTSD in Armed Forces Veterans (AFV), however the use of self-compassion approaches in AFV is under-researched. The current study utilised self-report and psychophysiological measures to investigate whether a single self-compassion experimental induction reduced hyperarousal symptoms (PTSD Cluster E symptoms) and increased feelings of social connectedness in AFV. The study hypothesised that there would be a decrease in hyperarousal symptoms and an increase in social connectedness, which would be associated with PTSD severity. Fifty-three AFV who had been deployed to a combat zone took part in the study, of which n = 15 (28.3%) currently met criteria for PTSD and n = 4 (7.5%) met criteria for Subsyndromal PTSD on the PCL-5. Participants listened to a recording of a Loving Kindness Meditation for self-compassion (LKM-S) and psychophysiological recordings were taken throughout. Participants completed state measures of hyperarousal and social connectedness before and after the LKM-S. Findings partially demonstrated that self-compassion can be elicited in an AFV population. However, changes on the self-report measures were largely not supported by psychophysiological measures, apart from skin conductance levels (SCL). The longevity of the effects observed in the study were not measured and should be investigated in future studies. Although this study has demonstrated that self-compassion can be elicited within the AFV population, further research is needed including to test a longer self-compassion intervention

    Search for L5 Earth Trojans with DECam

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    Most of the major planets in the Solar system support populations of co-orbiting bodies, known as Trojans, at their L4 and L5 Lagrange points. In contrast, Earth has only one known co-orbiting companion. This paper presents the results from a search for Earth Trojans (ETs) using the DECam instrument on the Blanco Telescope at CTIO. This search found no additional Trojans in spite of greater coverage compared to previous surveys of the L5 point. Therefore, the main result of this work is to place the most stringent constraints to date on the population of ETs. These constraints depend on assumptions regarding the underlying population properties, especially the slope of the magnitude distribution (which in turn depends on the size and albedo distributions of the objects). For standard assumptions, we calculate upper limits to a 90 per cent confidence limit on the L5 population of N_(ET) < 1 for magnitude H < 15.5, N_(ET) = 60–85 for H < 19.7, and N_(ET) = 97 for H = 20.4. This latter magnitude limit corresponds to Trojans ∼300 m in size for albedo 0.15. At H = 19.7, these upper limits are consistent with previous L4 ET constraints and significantly improve L5 constraints

    The use of an aircraft test stand for VTOL handling qualities studies

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    The VTOL flight tests stand for testing control concepts on the X-14B VSS aircraft in hover, is described. This stand permits realistic and safe piloted evaluation and checkout of various control systems and of parameter variations within each system to determine acceptability to the pilot. Pilots can use it as a practical training tool to practice procedures and flying techniques and become familiar with the aircraft characteristics. Some examples of test experience are given. The test stand allows the X14B to maneuver in hover from centered position + or - 9.7 deg in roll and + or - 9.3 deg in pitch, about + or - 6 deg in yaw, and + or - 15 cm in vertical translation. The unique vertical free flight freedom enables study of liftoffs and landings with power conditions duplicated. The response on the stand agrees well with that measured in free hovering flight, and pilot comments confirm this

    Peer Rejection and Friendships in Children with Attention-Deficit/Hyperactivity Disorder: Contributions to Long-Term Outcomes

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    Even after evidence-based treatment, Attention- Deficit/Hyperactivity Disorder (ADHD) is associated with poor long-term outcomes. These outcomes may be partly explained by difficulties in peer functioning, which are common among children with ADHD and which do not respond optimally to standard ADHD treatments. We examined whether peer rejection and lack of dyadic friendships experienced by children with ADHD after treatment contribute to long-term emotional and behavioral problems and global impairment, and whether having a reciprocal friend buffers the negative effects of peer rejection. Children with Combined type ADHD (N0300) enrolled in the Multimodal Treatment Study of Children with ADHD (MTA) were followed for 8 years. Peer rejection and dyadic friendships were measured with sociometric assessments after the active treatment period (14 or 24 months after baseline; M ages 9.7 and 10.5 years, respectively). Outcomes included delinquency, depression, anxiety, substance use, and general impairment at 6 and 8 years after baseline (Mean ages 14.9 and 16.8 years, respectively). With inclusion of key covariates, including demographics, symptoms ofADHD, ODD, and CD, and level of the outcome variable at 24 months, peer rejection predicted cigarette smoking, delinquency, anxiety, and global impairment at 6 years and global impairment at 8 years after baseline. Having a reciprocal friend was not, however, uniquely predictive of any outcomes and did not reduce the negative effects of peer rejection. Evaluating and addressing peer rejection in treatment planning may be necessary to improve long-term outcomes in children with ADHD

    Double infection with a resistant and a multidrug-resistant strain of Mycobacterium tuberculosis.

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    An immunocompetent patient was dually infected with a resistant and a multidrug-resistant strain of Mycobacterium tuberculosis (TB). The multidrug-resistant strain, which belongs to the W- strain/Beijing family, was first isolated after 3 months of therapy. Inappropriate treatment led to further drug resistance and unsuccessful therapy. Thus, additional infections with resistant M. tuberculosis strains should be considered when tuberculosis therapy fails

    CLIC4, an Intracellular Chloride Channel Protein, Is a Novel Molecular Target for Cancer Therapy

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    Chloride intracellular channel (CLIC)4 is a p53- and tumor necrosis factor α (TNFα)-regulated chloride channel protein that is localized to the mitochondria and cytoplasm of mouse and human keratinocytes. CLIC4 protein increases in differentiating keratinocytes and in keratinocytes exposed to DNA-damaging agents and metabolic inhibitors. Increasing CLIC4 levels by transduction of recombinant CLIC4 causes apoptosis. CLIC4 translocates to the nucleus under a variety of conditions of cell stress, and nuclear CLIC4 is associated with cell cycle arrest and accelerated apoptosis. Reduction of CLIC4 and several other CLIC family members by expressing a doxycycline-regulated CLIC4 antisense also causes apoptosis in squamous cancer cell lines. Expressing antisense CLIC4 in tumors derived from transplanting these cells into nude mice inhibits tumor growth, increases tumor apoptosis, and reduces tumor cell proliferation. Co-administration of TNFα intraperitoneally enhances the tumor-inhibitory influence of CLIC4 antisense expression. Together, these results suggest that CLIC4 is important for keratinocyte viability and may be a novel target for anti-cancer therapy
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