986 resultados para DEFENSE RESPONSES


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This study examined the effect of exercise intensity and duration during 5-day heat acclimation (HA) on cycling performance and neuromuscular responses. 20 recreationally trained males completed a ‘baseline’ trial followed by 5 consecutive days HA, and a ‘post-acclimation’ trial. Baseline and post-acclimation trials consisted of maximal voluntary contractions (MVC), a single and repeated countermovement jump protocol, 20 km cycling time trial(TT) and 5x6 s maximal sprints (SPR). Cycling trials were undertaken in 33.0 ± 0.8 °C and 60 ± 3% relative humidity.Core(Tcore), and skin temperatures (Tskin), heart rate (HR), rating of perceived exertion (RPE) and thermal sensation were recorded throughout cycling trials. Participants were assigned to either 30 min high-intensity (30HI) or 90 min low-intensity (90LI) cohorts for HA, conducted in environmental conditions of 32.0 ± 1.6 °C. Percentage change time to complete the 20 km TT for the 90LI cohort was significantly improved post-acclimation(-5.9 ± 7.0%; P=0.04) compared to the 30HI cohort (-0.18 ± 3.9%; P<0.05). The 30HI cohort showed greatest improvements in power output (PO) during post-acclimation SPR1 and 2 compared to 90LI (546 ± 128 W and 517 ± 87 W,respectively; P<0.02). No differences were evident for MVC within 30HI cohort, however, a reduced performance indicated by % change within the 90LI (P=0.04). Compared to baseline, mean Tcore was reduced post-acclimation within the 30HI cohort (P=0.05) while mean Tcore and HR were significantly reduced within the 90LI cohort (P=0.01 and 0.04, respectively). Greater physiological adaptations and performance improvements were noted within the 90LI cohort compared to the 30HI. However, 30HI did provide some benefit to anaerobic performance including sprint PO and MVC. These findings suggest specifying training duration and intensity during heat acclimation may be useful for specific post-acclimation performance.

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This thesis explores how planning policy and practice is responding to the challenge of climate change, particularly in contexts where neoliberal rationales and practices frame decision making. It documents patterns of devolving government responsibilities and experiences of market based mechanisms before reporting on institutional and professional responses to these conditions. The research centred on a qualitative case study and involved thematic content analysis of policy documents and informant interviews. The contribution of the research and thesis is to establish the outlook for climate change adaptation under neoliberal conditions, and to introduce strategies for planners operating within these conditions.

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Chronic inflammation is now recognized as a major cause of malignant disease. In concert with various mechanisms (including DNA instability), hypoxia and activation of inflammatory bioactive lipid pathways and pro-inflammatory cytokines open the doorway to malignant transformation and proliferation, angiogenesis, and metastasis in many cancers. A balance between stimulatory and inhibitory signals regulates the immune response to cancer. These include inhibitory checkpoints that modulate the extent and duration of the immune response and may be activated by tumor cells. This contributes to immune resistance, especially against tumor antigen-specific T-cells. Targeting these checkpoints is an evolving approach to cancer immunotherapy, designed to foster an immune response. The current focus of these trials is on the programmed cell death protein 1 (PD-1) receptor and its ligands (PD-L1, PD-L2) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Researchers have developed anti-PD-1 and anti-PDL-1 antibodies that interfere with the ligands and receptor and allow the tumor cell to be recognized and attacked by tumor-infiltrating T-cells. These are currently being studied in lung cancer. Likewise, CTLA-4 inhibitors, which have had success treating advanced melanoma, are being studied in lung cancer with encouraging results.

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Child sexual abuse is a major global public health concern, affecting one in eight children and causing massive costs including depression, unwanted pregnancy and HIV. The gravity of this global issue is reflected by the United Nations’ new effort to respond to sexual abuse in the 2015 Sustainable Development Goals. The fundamental policy aims are to improve prevention, identification and optimal responses to sexual abuse. However, as shown in our literature review, policymakers face difficult challenges because child sexual abuse is hidden, psychologically complex, and socially sensitive. This article contributes significant new ideas for international progress. Insights about required strategies are informed by an innovative multidisciplinary analysis of research from public health, medicine, social science, psychology, and neurology. Using an ecological model comprising individual, institutional and societal dimensions, we propose that two preconditions for progress are the enhancement of awareness of child sexual abuse, and of empathic responses towards its victims.

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Mycobacterium tuberculosis is a successful pathogen that overcomes numerous challenges presented by the immune system of the host. This bacterium usually establishes a chronic infection in the host where it may silently persist inside a granuloma until, a failure in host defenses, leads to manifestation of the disease. None of the conventional anti-tuberculosis drugs are able to target these persisting bacilli. Development of drugs against such persisting bacilli is a constant challenge since the physiology of these dormant bacteria is still not understood at the molecular level. Some evidence suggests that the in vivo environment encountered by the persisting bacteria is anoxic and nutritionally starved. Based on these assumptions, anaerobic and starved cultures are used as models to study the molecular basis of dormancy. This review outlines the problem of persistence of M. tuberculosis and the various in vitro models used to study mycobacterial latency. The basis of selecting the nutritional starvation model has been outlined here. Also, the choice of M. smegmatis as a model suitable for studying mycobacterial latency is discussed. Lastly, general issues related to oxidative stress and bacterial responses to it have been elaborated. We have also discussed general control of OxyR-mediated regulation and emphasized the processes which manifest in the absence of functional OxyR in the bacteria. Lastly, a new class of protein called Dps has been reviewed for its important role in protecting DNA under stress.

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Peruna kestää A-virusta estämällä sen leviämistä Peruna on maissin ohella maailman kolmanneksi tärkein ravintokasvi vehnän ja riisin jälkeen. Perunaa lisätään kasvullisesti mukuloita istuttamalla, jolloin virukset siirtyvät sairaiden siemenmukuloiden välityksellä kasvukaudesta toiseen. Virustauteja voi torjua ainoastaan terveen siemenperunan ja kestävien lajikkeiden avulla. Kestävyys perustuu usein siihen, että kasvi estää viruksen leviämisen tartuntakohdasta välttyäkseen virustaudilta. Tässä työssä tutkittiin kolmea perunan A-viruksen (PVA) liikkumista estävää kestävyysmekanismia perunassa. Lisäksi työn kokeelliseen osaan oleellisesti kuuluvaa virustartutusta varten kehitettiin uusi paranneltu versio geenipyssystä. Tämä itse rakennettu laite optimoitiin PVA:n tartuttamiseen mahdollisimman helposti ja pienin käyttökustannuksin. Tutkimuksen kohteena olleessa perunan risteytysjälkeläistössä oli PVA:ta kestäviä kasveja (ryhmä nnr), jotka estivät viruksen liikkumisen aiheuttamatta oireita tartutuskohdassa, sekä kasveja, joissa PVA aiheutti kuolioläikkinä näkyvän yliherkkyysvasteen (ryhmä HR). Molemmissa kestävyystyypeissä virus pystyi monistumaan ja leviämään solusta soluun paikallisesti, mutta liikkuminen muihin kasvinosiin nilan kautta estyi. Ryhmän nnr kasveissa PVA-tartunta ei aiheuttanut tilastollisesti merkitsevää muutosta useimpien geenien ilmenemiseen tartuntakohdassa. Ainoastaan geeniperhe, joka ilmentää tiettyä proteinaasi-inhibiittoria (PI), reagoi PVA:han 24 tuntia tartutuksesta. Kun tämän PVA:han reagoivan geeniperheen jäsenet hiljennettiin nnr- perunalinjoissa, ne muuttuivat alttiiksi PVA:lle ja virus levisi tartuntakohdasta muihin kasvinosiin. Tulos osoittaa, että PI on viruskestävyystekijä. Lisäksi muut tutkimuksessa saadut tulokset tukevat mahdollisuutta, että PI estää PVA:n P1-proteinaasin toimintaa. HR-linjoissa todettiin erilaisiin puolustusvasteisiin liittyvien PR-geenien aktivoitumista PVA-tartunnan seurauksena, mutta myös ilman sitä kasvien kasvettua mullassa noin neljä viikkoa. Sen sijaan solukkoviljelyssä tai vasta kaksi viikkoa mullassa kasvaneissa kasveissa vastaavaa ei vielä todettu. Tulos viittaa siihen, että HR-perunat reagoivat herkemmin ympäristöön ja/tai kasvin kehitysasteeseen laukaisten puolustusvasteita, jotka saattavat parantaa kestävyyttä taudinaiheuttajia vastaan. Kolmas tutkittu kestävyystyyppi havaittiin Pito-perunalajikkeessa. Se muistutti nnr-kestävyyttä siten, että myös siinä viruksen liikkuminen nilassa muihin kasvinosiin estyi. PVA:n todettiin pysähtyvän vasta lehtiruodin tyvelle muodostuvaan irtoamisvyöhykkeeseen, mitä havainnollistettiin käyttämällä muunnettua PVA-rotua, joka tuotti UV-valossa fluoresoivaa vihreää valoa. Tulos viittaa siihen, että virus ei pääse kulkemaan vyöhykkeeseen kuuluvan suojaavan kerroksen läpi, jollei sillä ole pääsyä nilaan. Tällainen kestävyys on tarpeen, jotta virus ei voi korvata nilakuljetusta solusta soluun leviämisellä. Tulokset tuovat uusia näkökulmia kasvien viruskestävyyteen ja auttavat selittämään viruksen nilakuljetuksen estymistä sekä solusta soluun leviämisen pysähtymistä kestävissä kasveissa.

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Aim: So far, most of the cognitive neuroscience studies investigating the development of brain activity in childhood have made comparisons between different age groups and ignored the individual stage of cognitive development. Given the wide variation in the rate of cognitive development, this study argues that chronological age alone cannot explain the developmental changes in brain activity. This study demonstrates how Piaget s theory and information on child s individual stage of development can complement the age-related evaluations of brain oscillatory activity. In addition, the relationship between cognitive development and working memory is investigated. Method: A total of 33 children (17 11-year-olds, 16 14-year-olds) participated in this study. The study consisted of behavioural tests and an EEG experiment. Behavioral tests included two Piagetian tasks (the Volume and Density task, the Pendulum task) and Raven s Standard Progressive Matrices task. During EEG experiment, subjects performed a modified version of the Sternberg s memory search paradigm which consisted of an auditorily presented memory set of 4 words and a probe word following these. The EEG data was analyzed using the event-related desynchronization / synchronization (ERD/ERS) method. The Pendulum task was used to assess the cognitive developmental stage of each subject and to form four groups based on age (11- or 14-year-olds) and cognitive developmental stage (concrete or formal operational stage). Group comparisons between these four groups were performed for the EEG data. Results and conclusions: Both age- and cognitive stage-related differences in brain oscillatory activity were found between the four groups. Importantly, age-related changes similar to those reported by previous studies were found also in this study, but these changes were modified by developmental stage. In addition, the results support a strong link between working memory and cognitive development by demonstrating differences in memory task related brain activity and cognitive developmental stages. Based on these findings it is suggested that in the future, comparisons of development of brain activity should not be based only on age but also on the individual cognitive developmental stage.