139 resultados para SUPPRESSION


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This article focuses on government acts of intimidation or the "policing of knowledge". It is more concerned with the suppression of academic freedom, the contractual ambiguities of contemporary criminological research and the ways in which independent scholarship is controlled or influenced by funding bodies than with the specifics of the original crime prevention research which forms the basis of the case study.

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In the last decade or so, we have witnessed the growth of web 2.0 technology and social networking platforms, and their rapid rise in popularity as methods of social interaction and communication. Yet, platforms such as Facebook and Twitter are not just online social phenomena, but can impact on the way the law and courts operate. This article highlights the issues that legal practitioners and courts need to be aware of in engaging with this technology, and suggests possible ways forward.

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Studies of orthographic skills transfer between languages focus mostly on working memory (WM) ability in alphabetic first language (L1) speakers when learning another, often alphabetically congruent, language. We report two studies that, instead, explored the transferability of L1 orthographic processing skills in WM in logographic-L1 and alphabetic-L1 speakers. English-French bilingual and English monolingual (alphabetic-L1) speakers, and Chinese-English (logographic-L1) speakers, learned a set of artificial logographs and associated meanings (Study 1). The logographs were used in WM tasks with and without concurrent articulatory or visuo-spatial suppression. The logographic-L1 bilinguals were markedly less affected by articulatory suppression than alphabetic-L1 monolinguals (who did not differ from their bilingual peers). Bilinguals overall were less affected by spatial interference, reflecting superior phonological processing skills or, conceivably, greater executive control. A comparison of span sizes for meaningful and meaningless logographs (Study 2) replicated these findings. However, the logographic-L1 bilinguals’ spans in L1 were measurably greater than those of their alphabetic-L1 (bilingual and monolingual) peers; a finding unaccounted for by faster articulation rates or differences in general intelligence. The overall pattern of results suggests an advantage (possibly perceptual) for logographic-L1 speakers, over and above the bilingual advantage also seen elsewhere in third language (L3) acquisition.

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Dengue fever is the most important mosquito-borne viral disease of humans with more than 50 million cases estimated annually in more than 100 countries. Disturbingly, the geographic range of dengue is currently expanding and the severity of outbreaks is increasing. Control options for dengue are very limited and currently focus on reducing population abundance of the major mosquito vector, Aedes aegypti. These strategies are failing to reduce dengue incidence in tropical communities and there is an urgent need for effective alternatives. It has been proposed that endosymbiotic bacterial Wolbachia infections of insects might be used in novel strategies for dengue control. For example, the wMelPop-CLA Wolbachia strain reduces the lifespan of adult A. aegypti mosquitoes in stably transinfected lines. This life-shortening phenotype was predicted to reduce the potential for dengue transmission. The recent discovery that several Wolbachia infections, including wMelPop-CLA, can also directly influence the susceptibility of insects to infection with a range of insect and human pathogens has markedly changed the potential for Wolbachia infections to control human diseases. Here we describe the successful transinfection of A. aegypti with the avirulent wMel strain of Wolbachia, which induces the reproductive phenotype cytoplasmic incompatibility with minimal apparent fitness costs and high maternal transmission, providing optimal phenotypic effects for invasion. Under semi-field conditions, the wMel strain increased from an initial starting frequency of 0.65 to near fixation within a few generations, invading A. aegypti populations at an accelerated rate relative to trials with the wMelPop-CLA strain. We also show that wMel and wMelPop-CLA strains block transmission of dengue serotype 2 (DENV-2) in A. aegypti, forming the basis of a practical approach to dengue suppression.

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The 'open window' theory is characterised by short term suppression of the immune system following an acute bout of endurance exercise. This window of opportunity may allow for an increase in susceptibility to upper respiratory illness (URI). Many studies have indicated a decrease in immune function in response to exercise. However, many studies do not indicate changes in immune function past 2 hours after the completion of exercise, consequently failing to determine whether these immune cells numbers, or importantly their function, return to resting levels before the start of another bout of exercise. Ten male 'A' grade cyclists (age 24.2 +/- 5.3 years; body mass 73.8 +/- 6.5 kg; VO(2peak) 65.9 +/- 7.1 mL.kg(-1).min(-1)) exercised for two hours at 90% of their second ventilatory threshold. Blood samples were collected pre-, immediately post-, 2 hours, 4 hours, 6 hours, 8 hours, and 24 hours post-exercise. Immune variables examined included total leukocyte counts, neutrophil function (oxidative burst and phagocytic function), lymphocyte subset counts (CD4(+), CD8(+), and CD16(+)/56(+)), natural killer cell activity (NKCA), and NK phenotypes (CD56(dim)CD16(+), and CD56(bright)CD16(-)). There was a significant increase in total lymphocyte numbers from pre-, to immediately post-exercise (p<0.01), followed by a significant decrease at 2 hours post-exercise (p<0.001). CD4(+) T-cell counts significantly increased from pre-exercise, to 4 hours post- (p<0.05), and 6 hours post-exercise (p<0.01). However, NK (CD16(+)/56(+)) cell numbers decreased significantly from pre-exercise to 4 h post-exercise (p<0.05), to 6 h post-exercise (p<0.05), and to 8 h post-exercise (p<0.01). In contrast, CD56(bright)CD16- NK cell counts significantly increased from pre-exercise to immediately post-exercise (p<0.01). Neutrophil oxidative burst activity did not significantly change in response to exercise, while neutrophil cell counts significantly increased from pre-exercise, to immediately post-exercise (p<0.05), and 2 hours post-exercise (p<0.01), and remained significantly above pre-exercise levels to 8 hours post-exercise (p<0.01). Neutrophil phagocytic function significantly decreased from 2 hours post-exercise, to 6 hours post- (p<0.05), and 24 hours post-exercise (p<0.05). Finally, eosinophil cell counts significantly increased from 2 hours post to 6 hours post- (p<0.05), and 8 hours post-exercise (p<0.05). This is the first study to show changes in immunological variables up to 8 hours post-exercise, including significant NK cell suppression, NK cell phenotype changes, a significant increase in total lymphocyte counts, and a significant increase in eosinophil cell counts all at 8 hours post-exercise. Suppression of total lymphocyte counts, NK cell counts and neutrophil phagocytic function following exercise may be important in the increased rate of URI in response to regular intense endurance training.

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Overexpression of the receptor tyrosine kinase EphB4 is common in epithelial cancers and linked to tumor progression by promoting angiogenesis, increasing survival and facilitating invasion and migration. However, other studies have reported loss of EphB4 suggesting a tumor suppressor function in some cancers. These opposing roles may be regulated by (i) the presence of the primary ligand ephrin-B2 that regulates pathways involved in tumor suppression or (ii) the absence of ephrin-B2 that allows EphB4 signaling via ligand-independent pathways that contribute to tumor promotion. To explore this theory, EphB4 was overexpressed in the prostate cancer cell line 22Rv1 and the mammary epithelial cell line MCF-10A. Overexpressed EphB4 localized to lipid-rich regions of the plasma membrane and confirmed to be ligand-responsive as demonstrated by increased phosphorylation of ERK1/2 and internalization. EphB4 overexpressing cells demonstrated enhanced anchorage-independent growth, migration and invasion, all characteristics associated with an aggressive phenotype, and therefore supporting the hypothesis that overexpressed EphB4 facilitates tumor promotion. Importantly, these effects were reversed in the presence of ephrin-B2 which led to a reduction in EphB4 protein levels, demonstrating that ligand-dependent signaling is tumor suppressive. Furthermore, extended ligand stimulation caused a significant decrease in proliferation that correlated with a rise in caspase-3/7 and -8 activities. Together, these results demonstrate that overexpression of EphB4 confers a transformed phenotype in the case of MCF-10A cells and an increased metastatic phenotype in the case of 22Rv1 cancer cells and that both phenotypes can be restrained by stimulation with ephrin-B2, in part by reducing EphB4 levels.

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Vitamin E is composed of two structurally similar compounds: tocopherols (TPs) and tocotrienols (T3). Despite being overshadowed by TP over the past few decades, T3 is now considered to be a promising anticancer agent due to its potent effects against a wide range of cancers. A growing body of evidence suggests that in addition to its antioxidative and pro-apoptotic functions, T3 possesses a number of anticancer properties that make it superior to TP. These include the inhibition of epithelial-to-mesenchymal transitions, the suppression of vascular endothelial growth factor tumor angiogenic pathway and the induction of antitumor immunity. More recently, T3, but not TP, has been shown to have chemosensitization and anti-cancer stem cell effects, further demonstrating the potential of T3 as an effective anticancer therapeutic agent. With most of the previous clinical studies on TP producing disappointing results, research has now focused on testing T3 as the next generation vitamin E for chemoprevention and cancer treatment. This review will summarize recent developments in the understanding of the anticancer effects of T3. We will also discuss current progress in clinical trials involving T3 as an adjuvant to conventional cancer therapy.

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27. Drugs in pregnancy and labour 27.1 Introduction 27.2 Common complaints in pregnancy and labour and their treatments 27.2.1 Pre-eclampsia and eclampsia. 27.2.2 Suppression of early labour 27.2.3 Neonatal respiratory distress syndrome 27.2.4 Postpartum haemorrhage 27.2.5 Prolactin excess 27.2.6 Nausea

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Purpose: To assess the effects of pre-cooling volume on neuromuscular function and performance in free-paced intermittent-sprint exercise in the heat. Methods: Ten male, teamsport athletes completed four randomized trials involving an 85-min free-paced intermittentsprint exercise protocol in 33°C±33% relative humidity. Pre-cooling sessions included whole body (WB), head+hand (HH), head (H) and no cooling (CONT), applied for 20-min pre-exercise and 5-min mid exercise. Maximal voluntary contractions (MVC) were assessed pre- and postintervention and mid- and post-exercise. Exercise performance was assessed with sprint times, % decline and distances covered during free-paced bouts. Measures of core(Tc) and skin (Tsk) temperatures, heart rate, perceptual exertion and thermal stress were monitored throughout. Venous and capillary blood was analyzed for metabolite, muscle damage and inflammatory markers. Results: WB pre-cooling facilitated the maintenance of sprint times during the exercise protocol with reduced % decline (P=0.04). Mean and total hard running distances increased with pre cooling 12% compared to CONT (P<0.05), specifically, WB was 6-7% greater than HH (P=0.02) and H (P=0.001) respectively. No change was evident in mean voluntary or evoked force pre- to post-exercise with WB and HH cooling (P>0.05). WB and HH cooling reduced Tc by 0.1-0.3°C compared to other conditions (P<0.05). WB Tsk was suppressed for the entire session(P=0.001). HR responses following WB cooling were reduced(P=0.05; d=1.07) compared to CONT conditions during exercise. Conclusion: A relationship between pre-cooling volume and exercise performance seems apparent, as larger surface area coverage augmented subsequent free-paced exercise capacity, in conjunction with greater suppression of physiological load. Maintenance of MVC with pre-cooling, despite increased work output suggests the role of centrally-mediated mechanisms in exercise pacing regulation and subsequent performance.

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Objectives: The current study investigated the change in neuromuscular contractile properties following competitive rugby league matches and the relationship with physical match demands. Design: Eleven trained, male rugby league players participated in 2–3 amateur, competitive matches (n = 30). Methods: Prior to, immediately (within 15-min) and 2 h post-match, players performed repeated counter-movement jumps (CMJ) followed by isometric tests on the right knee extensors for maximal voluntary contraction (MVC), voluntary activation (VA) and evoked twitch contractile properties of peak twitch force (Pt), rate of torque development (RTD), contraction duration (CD) and relaxation rate (RR). During each match, players wore 1 Hz Global Positioning Satellite devices to record distance and speeds of matches. Further, matches were filmed and underwent notational analysis for number of total body collisions. Results: Total, high-intensity, very-high intensity distances covered and mean speed were 5585 ± 1078 m, 661 ± 265, 216 ± 121 m and 75 ± 14 m min−1, respectively. MVC was significantly reduced immediately and 2 h post-match by 8 ± 11 and 12 ± 13% from pre-match (p < 0.05). Moreover, twitch contractile properties indicated a suppression of Pt, RTD and RR immediately post-match (p < 0.05). However, VA was not significantly altered from pre-match (90 ± 9%), immediately-post (89 ± 9%) or 2 h post (89 ± 8%), (p > 0.05). Correlation analyses indicated that total playing time (r = −0.50) and mean speed (r = −0.40) were moderately associated to the change in post-match MVC, while mean speed (r = 0.35) was moderately associated to VA. Conclusions: The present study highlights the physical demands of competitive amateur rugby league result in interruption of peripheral contractile function, and post-match voluntary torque suppression may be associated with match playing time and mean speeds.

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Phosphorylation and activation of Akt1 is a crucial signaling event that promotes adipogenesis. However, neither the complex multistep process that leads to activation of Akt1 through phosphorylation at Thr308 and Ser473 nor the mechanism by which Akt1 stimulates adipogenesis is fully understood. We found that the BSD domain–containing signal transducer and Akt interactor (BSTA) promoted phosphorylation of Akt1 at Ser473 in various human and murine cells, and we uncovered a function for the BSD domain in BSTA-Akt1 complex formation. The mammalian target of rapamycin complex 2 (mTORC2) facilitated the phosphorylation of BSTA and its association with Akt1, and the BSTA-Akt1 interaction promoted the association of mTORC2 with Akt1 and phosphorylation of Akt1 at Ser473 in response to growth factor stimulation. Furthermore, analyses of bsta gene-trap murine embryonic stem cells revealed an essential function for BSTA and phosphorylation of Akt1 at Ser473 in promoting adipocyte differentiation, which required suppression of the expression of the gene encoding the transcription factor FoxC2. These findings indicate that BSTA is a molecular switch that promotes phosphorylation of Akt1 at Ser473 and reveal an mTORC2-BSTA-Akt1-FoxC2–mediated signaling mechanism that is critical for adipocyte differentiation.

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This study examined relationships between competitive trait anxiety and coping strategies among ballet dancers. Participants were 104 classical dancers (81 females and 23 males) ranging in age from 15 to 35 years (mean 19.4 years; SD 3.8 years) from three professional ballet companies, two private dance schools, and two university dance courses in Australia. Participants completed the Modified COPE scale and the Sport Anxiety Scale. Trait anxiety scores, in particular for somatic anxiety and worry, were significant predictors of 7 of the 12 coping strategies (wishful thinking, r2 = 42.3%; selfblame, r2 = 35.7%; suppression of competing activities, r2 = 27.1%; venting of emotions, r2 = 23.2%; denial, r2 = 17.7%; effort, r2 = 16.6%; active coping, r2 = 14.3%). Approximately 96% of dancers could be classified correctly as high or low trait-anxious from their reported coping style. No significant effects of gender or status (professional versus students) were found. Findings showed that high trait-anxious athletes tend to use more maladaptive, emotion-focused coping strategies compared with low trait-anxious athletes; a tendency that has been proposed to lead to negative performance effects. Dancers who are by nature anxious about performance may need special attention to help them to learn to cope with performance-related stress. Med Probl Perform Art 18:59–64, 2003.

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Programmed cell death is characterized by a cascade of tightly controlled events that culminate in the orchestrated death of the cell. In multicellular organisms autophagy and apoptosis are recognized as two principal means by which these genetically determined cell deaths occur. During plant-microbe interactions cell death programs can mediate both resistant and susceptible events. Via oxalic acid (OA), the necrotrophic phytopathogen Sclerotinia sclerotiorum hijacks host pathways and induces cell death in host plant tissue resulting in hallmark apoptotic features in a time and dose dependent manner. OA-deficient mutants are non-pathogenic and trigger a restricted cell death phenotype in the host that unexpectedly exhibits markers associated with the plant hypersensitive response including callose deposition and a pronounced oxidative burst, suggesting the plant can recognize and in this case respond, defensively. The details of this plant directed restrictive cell death associated with OA deficient mutants is the focus of this work. Using a combination of electron and fluorescence microscopy, chemical effectors and reverse genetics, we show that this restricted cell death is autophagic. Inhibition of autophagy rescued the non-pathogenic mutant phenotype. These findings indicate that autophagy is a defense response in this necrotrophic fungus/plant interaction and suggest a novel function associated with OA; namely, the suppression of autophagy. These data suggest that not all cell deaths are equivalent, and though programmed cell death occurs in both situations, the outcome is predicated on who is in control of the cell death machinery. Based on our data, we suggest that it is not cell death per se that dictates the outcome of certain plant-microbe interactions, but the manner by which cell death occurs that is crucial.

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Sclerotinia sclerotiorum is a necrotrophic ascomycete fungus with an extremely broad host range. This pathogen produces the non-specific phytotoxin and key pathogenicity factor, oxalic acid (OA). Our recent work indicated that this fungus and more specifically OA, can induce apoptotic-like programmed cell death (PCD) in plant hosts, this induction of PCD and disease requires generation of reactive oxygen species (ROS) in the host, a process triggered by fungal secreted OA. Conversely, during the initial stages of infection, OA also dampens the plant oxidative burst, an early host response generally associated with plant defense. This scenario presents a challenge regarding the mechanistic details of OA function; as OA both suppresses and induces host ROS during the compatible interaction. In the present study we generated transgenic plants expressing a redox-regulated GFP reporter. Results show that initially, Sclerotinia (via OA) generates a reducing environment in host cells that suppress host defense responses including the oxidative burst and callose deposition, akin to compatible biotrophic pathogens. Once infection is established however, this necrotroph induces the generation of plant ROS leading to PCD of host tissue, the result of which is of direct benefit to the pathogen. In contrast, a non-pathogenic OA-deficient mutant failed to alter host redox status. The mutant produced hypersensitive response-like features following host inoculation, including ROS induction, callose formation, restricted growth and cell death. These results indicate active recognition of the mutant and further point to suppression of defenses by the wild type necrotrophic fungus. Chemical reduction of host cells with dithiothreitol (DTT) or potassium oxalate (KOA) restored the ability of this mutant to cause disease. Thus, Sclerotinia uses a novel strategy involving regulation of host redox status to establish infection. These results address a long-standing issue involving the ability of OA to both inhibit and promote ROS to achieve pathogenic success.

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This study examined the effect of 20 weeks resistance training on a range of serum hormones and inflammatory markers at rest, and following acute bouts of exercise in prostate cancer patients undergoing androgen deprivation. Ten patients exercised twice weekly at high intensity for several upper and lower-body muscle groups. Neither testosterone nor prostate-specific antigen changed at rest or following an acute bout of exercise. However, serum growth hormone (GH), dehydroepiandrosterone (DHEA), interleukin-6, tumor necrosis factor-alpha and differential blood leukocyte counts increased (P < 0.05) following acute exercise. Resistance exercise does not appear to compromise testosterone suppression, and acute elevations in serum GH and DHEA may partly underlie improvements observed in physical function.