• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 2
  • 1
  • Tagged with
  • 11
  • 11
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Neuroendocrine responses to psychological workload of military flying

Leino, T. (Tuomo) 17 November 1999 (has links)
Abstract The psychological workload a pilot is exposed to during military flying is considered to be high, and good stress tolerance is needed. During military flying a huge amount of environmental information is transformed to neural signals which finally lead to motor and behavioral changes, and also to chemial secretion of neuroendocrine hormones. This study deals with neuroendocrine measurements performed in four procedures: psychomotor test during military pilot selection, instrument flying (IFR) with piston-engine primary trainer, real and simulated jet trainer flight, and simulated combat fighter flight. Neuroendocrine hormones, hypothalamic CRH, pituitary ACTH, beta-endorphin, prolactin and vasopressin, the adrenal hormones cortisol, adrenaline and noradrenaline and a cardiac hormone, ANP, were assayed from plasma by using immunoassay and HPLC techniques. In the psychomotor test (procedure 1) plasma prolactin, ACTH and cortisol responses were associated with a high number of delayed responses, which was used as an indicator of information overload. Anticipatory type ACTH response, i.e. high ACTH level before the test, predicted poor overall result in the psychomotor test. In response to IFR flying (procedure II) the student pilots showed increased plasma prolactin, ACTH, cortisol, adrenaline and noradrenaline levels. Postflight adrenaline response correlated significantly with poor flight performance as well as a poor psychomotor test result. Low emotional control and high performance motivation measured by an aviation psychologist correlated significantly with neuroendocrine responses after the instrument flight. Flight with jet trainer (procedure III) led to increased plasma prolactin levels, evidently due to psychological workload, but no statistically significant plasma prolactin increase was found in the simulator. This suggests that psychological workload in the flight simulator is lower compared to real jet trainer. A significant ANP response to jet trainer flight was apparently associated with increased heart rate due to psychological workload of the flight mission. Simulated combat fighter flight (procedure IV) resulted in an anticipatory type stress reaction as judged from the elevated preflight plasma ACTH, and a direct type reaction was observed in cortisol. In one pilot the neuroendocrine activation was extreme and global, suggesting low stress tolerance under high information load. Increased neuroendocrine activation is associated with psychological workload of military flying. Neuroendocrine measurements can be used in a follow-up system of military pilots.
2

Simulation of a functionally distributed computing facility

Nikravan, Nasrin January 2010 (has links)
Photocopy of typescript. / Digitized by Kansas Correctional Industries
3

Antagomir Treatment for Deep-Space Simulated Changes in the Liver of Mice

Hayslip, Natalie P 01 January 2024 (has links) (PDF)
With the start of NASA’s Artemis program, astronauts will soon leave the protection of Earth’s magnetosphere. Previous studies have established a theme of liver dysregulation associated with the harmful radiation and microgravity experienced in deep space. MicroRNAs (miRNAs) are key regulators of many of the pathologies observed during and after spaceflight, including hepatic fibrosis, making them strong potential biomarkers and therapeutic targets. Therefore, in the present study we investigated the effects of simulated microgravity, galactic cosmic radiation (GCR), and solar particle events (SPE) on miRNAs and mRNAs involved in the TGF-β signaling pathway, a key regulator of fibrosis, senescence, and inflammation in the liver. We also analyzed the ability of an antagomir treatment which targets miR-16-5p, miR-125b-5p, and let-7a-5p to modulate these spaceflight-associated changes in liver health. Our results indicate that the observed miRNA profile widely varied depending on whether GCR or SPE irradiation were administered. Likewise, while the antagomir treatment was successful at downregulating expression of its target mRNAs, the type of radiation received greatly influenced whether the miRNA shifts observed correlated with changes in downstream gene expression; the GCR group was the most effected and the SPE the least in terms of both miRNA and mRNA expression. Overall, the current study highlights the profound effects of cosmic radiation on the hepatic miRNA profile and confirms the potential of antagomir treatment as a therapeutic for spaceflight induced changes in expression.
4

The Effect of Study Skills Training Intervention on United States Air Force Aeromedical Apprentices

Griffith, John Clark 08 1900 (has links)
The study examined the effects of a study skills training intervention course on U.S. Air Force Aeromedical Apprentices with five main purposes. The first was to examine the relationship between study skills training and the number of times students required academic interventions outside of normal class time. The second purpose was to examine the relationship between study skills training and end of course averages. The third was to determine the relationship between study skills training and the amount of additional instruction, measured in time, students required. The fourth purpose examined the relationship between study skills training and graduation rates. The final purpose was to recommend areas for further research.
5

Inteligibilidade de fala de usuários de implante coclear na situação de pilotos de helicóptero / Speech recognition of cochlear implant users at the situation of helicopter pilots

Caldeira, Juliana Maria Araujo 25 September 2017 (has links)
Introdução: Apesar do usuário de implante coclear (IC) apresentar limiares tonais audiométricos compatíveis com os critérios exigidos para pilotos à obtenção do certificado médico aeronáutico (CMA), a inteligibilidade da fala via rádio no ambiente de ruído da aeronave pode não ser suficiente para uma boa comunicação. As regras de aptidão para o CMA de pilotos de 1ª classe constam no manual da Organização Internacional da Aviação Civil (ICAO): devem escutar em cada um dos ouvidos separadamente, até 35 dB NA nas frequências de 500, 1 000 e 2 000 Hz, e até 50 dB NA em 3 000 Hz. Pilotos também podem ser aprovados em teste de inteligibilidade no ruído com exigência mínima de acerto de 80% das palavras foneticamente equilibradas. Objetivos: (1) avaliar se implantados, que atingem limiares tonais exigidos pela ICAO, tem inteligibilidade da fala suficiente para comunicação via rádio, na situação de ruído da cabine do helicóptero; (2) avaliar se recursos de atenuação de ruído otimizam a inteligibilidade da fala de usuários de IC; (3) avaliar se a comunicação pelo rádio prejudica a inteligibilidade de usuários de IC. Métodos: Foi avaliada a performance em testes de inteligibilidade de 12 usuários de IC com surdez pós-lingual, que preencheram os critérios audiométricos da ICAO, e de 3 pilotos normo-ouvintes (controles). Realizamos testes com sentenças, números e dissílabos em diferentes situações: no silêncio da cabine audiométrica, no helicóptero desligado (testes via rádio), no helicóptero ligado sem e com ativação do sistema antirruído do fone e no helicóptero ligado através da conexão direta do processador de fala do IC ao sistema de rádio da aeronave. Resultados: Observamos diferenças significativas para todos os testes realizados quando comparamos as respostas no silêncio e na situação de ruído com o helicóptero ligado. Ao reduzirmos a exposição de ruído, ativando o sistema antirruído do fone, observamos melhora significativa apenas para as frases. Já quando reduzimos ao máximo a exposição ao ruído pela conexão direta via cabo entre o implante e o sistema de rádio da aeronave, houve melhora significativa nos resultados para números e dissílabos. Houve piora significativa nos testes com dissílabos na situação do helicóptero desligado (rádio) em relação à cabine audiométrica. Conclusões: Os usuários de IC não alcançaram níveis de inteligibilidade de fala compatíveis com os requisitos auditivos para pilotos da aviação civil nos testes realizados no helicóptero. Os recursos de atenuação de ruído propostos auxiliaram na inteligibilidade de fala dos usuários de IC. A comunicação pelo rádio interferiu de forma significativa na inteligibilidade dos usuários de IC / Introduction: Although the cochlear implant (CI) user meets audiometric thresholds for the criteria required for pilots, the speech recognition through the radio in the aircraft noise condition may not be sufficient for good communication. Rules for 1st class pilots are given in the International Civil Aviation Organization (ICAO) manual: they must hear in each ear separately, up to 35 dB NA at 500, 1 000 and 2 000 Hz, and up to 50 dB NA at 3 000 Hz. Pilots can also be fit if they understand at least 80% of the phonetically balanced words against a background noise. Objectives: (1) to assess if CI users, who reach thresholds required by the ICAO also achieve speech recognition levels good for radio communication in the noise situation of the helicopter cockpit; (2) to evaluate if noise attenuation features optimize the speech recognition of CI users; (3) evaluate whether radio communication affects the speech recognition of CI users. Methods: We evaluated the performance of 12 CI users with post-lingual deafness, who met ICAO audiometric criteria, and three normal hearing (control) pilots in intelligibility tests. We performed tests with sentences, numbers and disyllables in different situations: in the quiet (sound proof booth), in the helicopter with the engine off (radio tests), in the helicopter with the engine running, without and with activation of the anti-noise system of the headphones and in the helicopter (engine turned on) through the direct connection of the speech processor of the CI to the aircraft\'s radio system. Results: We observed significant differences for all tests performed when we compared scores in quiet and in the noisy environment of the helicopter with engine turned on. When the noise exposure was reduced by activating the headphones anti-noise system, we observed significant improvement only for the sentences. We found a significant improvement in the results for numbers and disyllables when we reduced the exposure to noise by the direct cable connection between the CI and the aircraft radio system. We also observed a significant worsening in the disyllabic speech perception in the helicopter even with the engine off (quiet).Conclusions: In the helicopter environment, CI subjects did not achieve levels of speech recognition requirements for civil aviation pilots. The proposed noise attenuation features offered improvement for speech recognition of CI users. Radio communication significantly interfered with speech recognition in CI users
6

Inteligibilidade de fala de usuários de implante coclear na situação de pilotos de helicóptero / Speech recognition of cochlear implant users at the situation of helicopter pilots

Juliana Maria Araujo Caldeira 25 September 2017 (has links)
Introdução: Apesar do usuário de implante coclear (IC) apresentar limiares tonais audiométricos compatíveis com os critérios exigidos para pilotos à obtenção do certificado médico aeronáutico (CMA), a inteligibilidade da fala via rádio no ambiente de ruído da aeronave pode não ser suficiente para uma boa comunicação. As regras de aptidão para o CMA de pilotos de 1ª classe constam no manual da Organização Internacional da Aviação Civil (ICAO): devem escutar em cada um dos ouvidos separadamente, até 35 dB NA nas frequências de 500, 1 000 e 2 000 Hz, e até 50 dB NA em 3 000 Hz. Pilotos também podem ser aprovados em teste de inteligibilidade no ruído com exigência mínima de acerto de 80% das palavras foneticamente equilibradas. Objetivos: (1) avaliar se implantados, que atingem limiares tonais exigidos pela ICAO, tem inteligibilidade da fala suficiente para comunicação via rádio, na situação de ruído da cabine do helicóptero; (2) avaliar se recursos de atenuação de ruído otimizam a inteligibilidade da fala de usuários de IC; (3) avaliar se a comunicação pelo rádio prejudica a inteligibilidade de usuários de IC. Métodos: Foi avaliada a performance em testes de inteligibilidade de 12 usuários de IC com surdez pós-lingual, que preencheram os critérios audiométricos da ICAO, e de 3 pilotos normo-ouvintes (controles). Realizamos testes com sentenças, números e dissílabos em diferentes situações: no silêncio da cabine audiométrica, no helicóptero desligado (testes via rádio), no helicóptero ligado sem e com ativação do sistema antirruído do fone e no helicóptero ligado através da conexão direta do processador de fala do IC ao sistema de rádio da aeronave. Resultados: Observamos diferenças significativas para todos os testes realizados quando comparamos as respostas no silêncio e na situação de ruído com o helicóptero ligado. Ao reduzirmos a exposição de ruído, ativando o sistema antirruído do fone, observamos melhora significativa apenas para as frases. Já quando reduzimos ao máximo a exposição ao ruído pela conexão direta via cabo entre o implante e o sistema de rádio da aeronave, houve melhora significativa nos resultados para números e dissílabos. Houve piora significativa nos testes com dissílabos na situação do helicóptero desligado (rádio) em relação à cabine audiométrica. Conclusões: Os usuários de IC não alcançaram níveis de inteligibilidade de fala compatíveis com os requisitos auditivos para pilotos da aviação civil nos testes realizados no helicóptero. Os recursos de atenuação de ruído propostos auxiliaram na inteligibilidade de fala dos usuários de IC. A comunicação pelo rádio interferiu de forma significativa na inteligibilidade dos usuários de IC / Introduction: Although the cochlear implant (CI) user meets audiometric thresholds for the criteria required for pilots, the speech recognition through the radio in the aircraft noise condition may not be sufficient for good communication. Rules for 1st class pilots are given in the International Civil Aviation Organization (ICAO) manual: they must hear in each ear separately, up to 35 dB NA at 500, 1 000 and 2 000 Hz, and up to 50 dB NA at 3 000 Hz. Pilots can also be fit if they understand at least 80% of the phonetically balanced words against a background noise. Objectives: (1) to assess if CI users, who reach thresholds required by the ICAO also achieve speech recognition levels good for radio communication in the noise situation of the helicopter cockpit; (2) to evaluate if noise attenuation features optimize the speech recognition of CI users; (3) evaluate whether radio communication affects the speech recognition of CI users. Methods: We evaluated the performance of 12 CI users with post-lingual deafness, who met ICAO audiometric criteria, and three normal hearing (control) pilots in intelligibility tests. We performed tests with sentences, numbers and disyllables in different situations: in the quiet (sound proof booth), in the helicopter with the engine off (radio tests), in the helicopter with the engine running, without and with activation of the anti-noise system of the headphones and in the helicopter (engine turned on) through the direct connection of the speech processor of the CI to the aircraft\'s radio system. Results: We observed significant differences for all tests performed when we compared scores in quiet and in the noisy environment of the helicopter with engine turned on. When the noise exposure was reduced by activating the headphones anti-noise system, we observed significant improvement only for the sentences. We found a significant improvement in the results for numbers and disyllables when we reduced the exposure to noise by the direct cable connection between the CI and the aircraft radio system. We also observed a significant worsening in the disyllabic speech perception in the helicopter even with the engine off (quiet).Conclusions: In the helicopter environment, CI subjects did not achieve levels of speech recognition requirements for civil aviation pilots. The proposed noise attenuation features offered improvement for speech recognition of CI users. Radio communication significantly interfered with speech recognition in CI users
7

Neck pain in air force pilots : on risk factors, neck motor function and an exercise intervention /

Äng, Björn, January 2007 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.
8

An analysis of parameters of the U.S. pilot population from 1983-2005 from a scientific information system point of view : a foundation for computational epidemiological studies /

Rogers, Paul B. January 2007 (has links) (PDF)
Thesis--University of Oklahoma. / Bibliography: leaves 131-132.
9

Radio speech communication and workload in military aviation:a human factors perspective

Lahtinen, T. (Taija) 29 November 2016 (has links)
Abstract Military aviation is characterised by challenging working environments. Even though flying is a heavily visual task, much of the most important information is expressed aurally, via radio. The purpose of this study is to investigate the characteristics of radio communication in military aviation environments, the effect of workload on radio communication, as well as the functionality of a new hearing protection system. Flight simulator (F/A-18 Hornet simulator) and heart rate analysis were used to analyse the effect of an increased workload on radio communication. In addition to this, two survey studies were conducted, the first to investigate the prevalence and nature of radio communication problems in military aviation environments, and the second for evaluating the functionality of a new hearing protection solution (moulded communication ear plugs, m-CEPs) for military pilots. In the flight simulator, pilots’ heart rate reflected the level of mental workload. Changes in radio communication were observed during a high workload: The total amount of communication, as well as informing and requesting messages increased. A decrease in acknowledgements was observed. This reflects a change in the team communication tactics during information-loaded flight phases. In survey studies, radio speech communication problems occurred during 14% of the flight time. The most prevalent problems included multiple speakers and overlapping speech on the radio frequency band, missing acknowledgments, and high background noise, especially during helicopter operations. During their career, 18% of the respondents had encountered a potentially dangerous event caused by radio communication problems. The pilots reported a high motivation to use enhanced hearing protection systems. m-CEPs were shown to be a promising tool for improving hearing protection and radio communication: they were considered to be better than the previous hearing protectors, and the pilots reported that they improve the experienced speech intelligibility. However, discomfort and technical problems remain a problem. In the challenging hearing conditions of military aviation, the high quality of radio communication and hearing protection remain important. In the future, radio communication training should be improved and focused on team communication training. The technical development of hearing protection devices should be continued to assure the best possible comfort and technical reliability. / Tiivistelmä Sotilaslentäjä työskentelee fyysisesti, psyykkisesti ja kognitiivisesti hyvin haastavassa monitehtäväympäristössä. Radiopuheviestinnän onnistuminen on lentoturvallisuuden ja tehtävätehokkuuden kannalta olennaista, sillä merkittävä osa turvallisuuden kannalta kriittisestä informaatiosta välitetään puheella radioteitse. Tämän väitöstutkimuksen tavoitteena on selvittää radiopuheviestinnän ongelmien esiintymistä ja luonnetta, kuormituksen vaikutusta radiopuheviestintään sekä uuden kuulonsuojausjärjestelmän toimivuutta sotilaslentäjän työssä. Tutkimus toteutettiin lentosimulaattorissa sekä kahdella kyselytutkimuksella. F/A-18 Hornet -simulaattorissa tutkittiin sykeanalyysin avulla lentotehtävän psyykkisen kuormituksen vaikutusta radiopuheviestintään. Kyselytutkimuksilla selvitettiin radiopuheviestintäongelmien yleisyyttä ja luonnetta sekä uuteen kuulonsuojausjärjestelmään (yksilöllisesti valettu kommunikaatiokuulosuojain) liittyviä tekijöitä. Sykeanalyysi osoittautui käyttökelpoiseksi psyykkisen kuormituksen arviontiin simulaattorissa. Radiopuheviestintä muuttui kuormittavassa lentovaiheessa: viestinnän määrä lisääntyi; informoivat ja kysyvät viestit lisääntyivät; ja kuittaukset vähenivät. Kyselytutkimuksissa lennon aikaisia radiopuheviestinnän ongelmia raportoitiin esiintyvän 14 % lentoajasta. Suuri puhujien määrä ja päällekkäinen puhe radiojaksolla, kuittausten puuttuminen sekä taustamelu varsinkin helikopteritoiminnassa olivat merkittävimpiä ongelmia. Vastaajista 18 % kertoi kohdanneensa urallaan läheltä piti- tai vaaratilanteen, johon radiopuheviestinnän ongelma oli myötävaikuttanut. Lentäjät olivat hyvin motivoituneita käyttämään uusia kuulonsuojausjärjestelmiä. Yksilöllisesti valetut kommunikaatiokuulosuojaimet vaikuttavat lupaavalta ratkaisulta kuulonsuojauksen ja viestinnän parantamiseen. Lentäjät pitivät niitä parempina kuin aiemmat kuulonsuojausjärjestelmät, ja niiden raportoitiin parantavan puheen ymmärrettävyyttä sotilasilmailun haastavissa kuunteluolosuhteissa. Mukavuusongelmia ja teknisiä ongelmia esiintyi kuitenkin edelleen runsaasti. Sotilasilmailun haastavissa kuunteluolosuhteissa laadukas radioviestintä ja toimiva kuulonsuojaus ovat tärkeitä. Radiopuheviestinnän harjoittelussa tulisi panostaa tehtäviä suorittavien ryhmien keskinäisen viestinnän (team communication) parantamiseen. Kuulonsuojausjärjestelmiä tulee edelleen kehittää.
10

On neck load among helicopter pilots : effects of head-worn equipment, whole-body vibration and neck position /

Thuresson, Marcus, January 2005 (has links) (PDF)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.

Page generated in 0.0903 seconds