15 resultados para Difference frequency generation (DFG)

em Deakin Research Online - Australia


Relevância:

40.00% 40.00%

Publicador:

Resumo:

Internet-based interventions with therapist support have proven effective for treating a range of mental health conditions. This study examined whether frequency of therapist contact affected treatment outcomes. Fifty-seven people with panic disorder (including 32 with agoraphobia) were randomly allocated to an 8-week Internet-based cognitive behavioural treatment intervention (Panic Online) with either frequent (three e-mails per week) or infrequent (one e-mail per week) support from a psychologist. Posttreatment, intention-to-treat analyses revealed that both treatments were effective at improving panic disorder and agoraphobia severity ratings, panicrelated cognitions, negative affect, and psychological and physical quality of life domains, with no differences between conditions. High end-state functioning was achieved by 28.6% of the frequent and infrequent participants, respectively. Therapist alliance, treatment credibility, and satisfaction also did not differ between groups, despite significantly greater therapist time invested in the frequent contact condition. The results provide evidence that the effectiveness of Internet-based mental health interventions may be independent of the frequency of therapist support and may, therefore, be more cost-effective than previously reported.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Aim : In this paper, the first of 4 stages of a large study aiming to develop culturally and clinically valid clinical indicators to flag the achievement of mental health nursing standards of practice in New Zealand are described.

Methods :
A bicultural design was employed throughout the research project to ensure that nurses' views of practice and the cultural differences between New Zealand's indigenous Maori and non-Maori peoples could be identified. Accordingly, separate focus groups of Maori- and non-Maori-experienced mental health nurses were asked to develop lists of statementd reflective of the Australian and New Zealand College of Mental Health Nurses' Standards of Practice in New Zealand.

Results : The focus group participants produces 473 statements, which were synthesized into 190 clinical indicator statements. In keeping with the bicultural research design, Maori and non-Maori data were analysed separately until the data were merged to provide a single set of indicator statements. Although both Maori and non-Maori groups wrote statements relevant to clinical practice, there was a difference in the way the 2 groups addressed cultural issues. The Maori focus group wrote statements about cultural issues for 4 of the 6 Standards of Practice, whereas the non-Maori focus group participants wrote statements about cultural issues for only the Standard focusing on cultural safety.

Conclusion :
The research design of this project in mental health nursing was unique in that it sought the perspectives of both indigenous and non-indigenous nurses about quality mental health nursing practice related to the professional standards of practice. The involvement of Maori and non-Maori mental health nurses enhanced the cultural and clinical validity of the study and the obtained from it. The bicultural approach adopted for the study highlights the need for more mental health nursing research involving indigenous partners.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

We tested the hypothesis that there are sex differences in the inhibitory effect of cortisol on pulsatile LH secretion and pituitary responsiveness to GnRH in gonadectomized sheep. In experiment 1, pulsatile LH secretion was examined in gonadectomized ewes and rams infused with either saline, a low (250 µg/kg·h) or a high (500 µg/kg·h) dose of cortisol for 30 h. In experiment 2, direct pituitary actions of cortisol were assessed by monitoring LH pulse amplitude in response to exogenous GnRH in hypothalamo-pituitary disconnected ewes and rams infused with the low dose of cortisol. In experiment 1, the mean (±SEM) plasma LH concentration was (P < 0.05) reduced significantly during cortisol infusion in both sexes, but the effect was greater in rams. In ewes, LH pulse amplitude and frequency were reduced (P < 0.05) at the high, but not the low, cortisol dose, whereas total LH output (LH pulse amplitude multiplied by frequency) was reduced (P < 0.05) at both doses. In rams, LH pulse frequency and amplitude and total LH output were (P < 0.05) reduced significantly at both cortisol doses. In experiment 2, plasma LH concentration and pulse amplitude in response to exogenous GnRH were not affected by infusion of cortisol in either sex. We conclude that gonadectomized rams are more sensitive than gonadectomized ewes to the effects of cortisol to inhibit LH secretion and that sex differences exist in the specific actions of cortisol on LH pulses. The results of experiment 2 suggest that intact hypothalamic input to the pituitary is necessary for cortisol to inhibit pituitary responsiveness to GnRH.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

It is common practice for captive birds to be kept under fluorescent lighting, which typically flickers at either 100Hz (UK) or 120 Hz (USA). Such lighting was developed for human vision and it is thought that birds may be able to detect higher frequencies of flicker than humans. For humans, 100Hz fluorescent lighting has been linked to eyestrain, headaches and migraine, even though this rate of flicker is above the human perceptual flicker-fusion frequency of around 60 Hz. Keeping birds under 100 Hz lighting is therefore potentially detrimental to their welfare. We studied the preferences of wild-caught European starlings, Sturnus vulgaris, for high-frequency (HF, >30 kHz) fluorescent lighting versus conventional low-frequency (LF, 100 Hz) fluorescent lighting. The flicker frequency of the HF lighting would be undetectable to the nervous system of any animal. We also exposed starlings to either HF or LF light for 2 weeks, and investigated the degree of stress caused by each environment by monitoring their behaviour and plasma corticosterone levels. Groups of starlings showed a preference for HF lighting over LF lighting (P < 0.001), which indicates that they can detect a difference between the two lighting conditions and find the HF lighting preferable. However, there were no measurable differences in behaviour or plasma corticosterone levels when the birds were housed under either HF or LF for 2 weeks, thus providing initial evidence that housing starlings under 100Hz lighting may not be detrimental to the welfare of starlings during early captivity. (C) 2003 Elsevier B.V. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Test procedures and their accuracy in determining critical fall height (CFH) on sporting grounds are paramount to player safety. The procedure currently adopted for synthetic turf in Australian football [1] consists of four consecutive drops at various drop heights at three test locations on the sample. The quantity and packing of the infill in third-generation turf and the pooling effect of the rubber particles with consecutive drops suggests that the current standard protocol may need re-assessment. Therefore, the purpose of this pilot study was to investigate whether current methods of testing for CFH are appropriate for third-generation synthetic turf or whether an alternative or adapted method needs to be developed. CFH was measured, using a HISUN Uniaxe-II Impact Tester, on 12 combinations of synthetic turf samples (four different products with three shock pad options). Three conditions were investigated on each sample; the existing protocol; an alternative 12 single-drop protocol and four single drops from the CFH determined from the existing protocol. A significant difference was found for both absolute and percentage difference between the existing and 12 single-drop protocol, with p = 0.001 and t = 4.33 and p < 0.001 and t = 6.03, respectively. There was also a significant difference between the CFH reached with and without a shock pad for both the existing protocol and the 12 single-drop protocol. The results of this pilot study demonstrate that differences do occur with alterations to the existing protocol and highlight the need for a more detailed characterisation of testing methods on third-generation synthetic turf and the response of surfaces to them.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper investigates the location and velocity estimation problem involving multiple targets using the phase difference and frequency shift of the returned Doppler modulated signal. The minimal receiver configuration that addresses the data association and missing information problem is presented for the case of linear arrays. Non-linearly modeled Doppler radar measurements are used to obtain an accurate estimate of the target dynamics progressively in a linear framework utilizing a recently developed robust state estimation approach.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Although the link between exercise and body image is well documented, the considerable inter-individual variability in this relationship has been largely ignored. Therefore, the aim of the present study was to test the contributions of key body image and exercise-related moderators (age, body mass index (BMI), exercise frequency, trait body dissatisfaction, internalisation of appearance standards, and body surveillance tendencies) in predicting variability in the exercise-body satisfaction relationship. Thirty-seven undergraduate women completed a questionnaire containing the above trait-based measures and then carried a Personal Digital Assistant (PDA) for a 7-day period. Participants were instructed to use the PDA to self-report their state body satisfaction immediately following an exercise session and also when the PDA signalled at each of six random intervals throughout the day. Multilevel modelling revealed a bi-directional relationship between exercise and state body satisfaction. Moreover, post-exercise increases in state body satisfaction were strongest for individuals who were younger and engaged in regular exercise, and weakest for individuals with high BMI and/or the tendency to compare their appearance with others. These findings highlight potential limits on the efficacy of exercise-based therapy for body image disturbances.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Aims: Patients’ perceptions about weight-related stigma and discrimination were assessed in 2 groups of patients, obese and laparoscopic adjustable gastric banding (LAGB).

Methods: Seven focus group sessions were held including a total of 32 women, 8 obese (body mass index 35+) and 24 who had lost 50&percnt; of excess weight following bariatric surgery. During the sessions, participants were asked to consider their experiences in situations including general, family, friends, work place, medical, and educational settings.

Results: Whilst perceptions of discrimination and stigmatisation were common and affected many life situations, they were less prevalent than previous reports. It appeared that it was not the frequency or number of events which affected an individual but the intensity of the experience. Younger women reported greater discrimination than older women and felt the social consequences of obesity to a greater extent. Older women were more concerned about the consequences of being overweight on their health.

Conclusions: Women who had lost weight considered that aspects of their own behaviours when obese contributed to their experiences of discrimination and stigmatisation. Perceptions of discrimination and stigmatisation appear to be influenced by age and current weight status.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Some people who experience migraine demonstrate reduced visual contrast sensitivity that is measurable between migraines. Contrast sensitivity loss to low spatial frequency gratings has been previously attributed to possible impairment of magnocellular pathway function. This study measured contrast sensitivity using low spatial frequency targets (0.25–4 c/deg) where the adaptation aspects of the stimuli were designed to preferentially assess either magnocellular or parvocellular pathway function (steady and pulsed pedestal technique). Twelve people with migraine with measured visual field abnormalities and 17 controls participated. Subjects were tested foveally and at 10° eccentricity. Foveally, there was no significant difference in group mean contrast sensitivity. At 10°, the migraine group demonstrated reduced contrast sensitivity for both the stimuli designed to assess magnocellular and parvocellular function (P < 0.05). The functional deficits measured in this study infer that abnormalities of the low spatial frequency sensitive channels of both pathways contribute to contrast sensitivity deficits in people with migraine.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The research reported in this paper examined spoken mathematics in particular well-taught classrooms in Australia, China (both Shanghai and Hong Kong), Japan, Korea and the USA from the perspective of the distribution of responsibility for knowledge generation in order to identify similarities and differences in classroom practice and the implicit pedagogical principles that underlie those practices. The methodology of the Learner’s Perspective Study (LPS) documented the voicing of mathematical ideas in public discussion and in teacher-student conversations and the relative priority accorded by different teachers to student oral contributions to classroom activity. Significant differences were identified among the classrooms studied, challenging simplistic characterisations of ‘the Asian classroom’ as enacting a single pedagogy, and suggesting that, irrespective of cultural similarities, local pedagogies reflect very different assumptions about learning and instruction. We have employed spoken mathematical terms as a form of surrogate variable, possibly indicative of the location of the agency for knowledge generation in the various classrooms studied (but also of interest in itself). The analysis distinguished one classroom from another on the basis of “public oral interactivity” (the number of utterances in whole class and teacher-student interactions in each lesson) and “mathematical orality” (the frequency of occurrence of key mathematical terms in each lesson). Classrooms characterized by high public oral interactivity were not necessarily sites of high mathematical orality. In particular, the results suggest that one characteristic that might be identified with a national norm of practice could be the level of mathematical orality: relatively high mathematical orality characterising the mathematics classes in Shanghai with some consistency, while lessons in Seoul and Hong Kong consistently involved much less frequent spoken mathematical terms. The relative contributions of teacher and students to this spoken mathematics provided an indication of how the responsibility for knowledge generation was shared between teacher and student in those classrooms. Specific analysis of the patterns of interaction by which key mathematical terms were introduced or solicited revealed significant differences. It is suggested that the empirical investigation of mathematical orality and its likely connection to the distribution of the responsibility for knowledge generation are central to the development of any theory of mathematics instruction.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

 Questions: Do nurse plant interactions significantly influence understorey vegetation diversity in a large, semi-arid, shrub-dominated wetland? How do the modes and net effects of nurse plant interactions vary spatially along a flood frequency gradient, and temporally in response to drying? Location: Narran Lakes Ramsar site, New South Wales, Australia. Methods: Microhabitat characteristics, understorey vegetation and germinable soil seed banks were investigated in shrub and open habitats across a flood frequency gradient in a large, semi-arid wetland dominated by open shrubland under productive conditions following floodwater recession and again following 6 mo of drought. Split-plot ANOVA and multivariate analyses were used to determine the effects of shrubs on microhabitat character, understorey vegetation cover, species diversity, richness and composition and germinable soil seed banks. Results: Microhabitat characteristics, including canopy cover, litter cover and soil character, all differed between shrub and open habitats, especially in the most frequently flooded sites. Under productive conditions following flooding, lignum shrubs suppressed understorey vegetation cover but increased species richness at the site scale across the flood frequency gradient and, in the most frequently flooded sites, supported higher species density at a microhabitat scale. Under dry conditions, lignum shrubs had a positive effect on understorey vegetation cover, species richness and species density across the flood frequency gradient, but particularly in frequently flooded sites. A significant difference in soil seed bank composition between shrub and open habitats was only observed in frequently flooded sites. Conclusions: Nurse plant interactions appear to play an important role in determining understorey vegetation diversity in the lignum shrubland of the Narran Lakes wetland system. The modes and net effects of these nurse plant interactions vary in space and time in relation to flood history and drying. Positive interactions, probably involving microhabitat amelioration, appear to be particularly important to plant diversity and abundance under dry conditions. Under more favourable wetter conditions, lignum shrubs also contribute to understorey vegetation diversity by facilitating the establishment of different species than those dominating open habitats. Our findings have implications for the management of perennial shrubs and hydrological regimes in such wetlands.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper examines how young people of migrant background in Australia make meaning of cultural, ethnic and racial difference to work out belonging in times of super-diversity. It asks what functions difference still has for a generation growing up within conditions of proliferating diversity that demand and accommodate competing constructions of cultural identities. It suggests that young people's narratives about difference depend on the space of belonging, and explores how young people use difference differently depending on whether they are articulating membership in the local community, the nation or youth culture.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: Accurate dietary assessment is key to understanding nutrition-related outcomes and is essential for estimating dietary change in nutrition-based interventions. OBJECTIVE: The objective of this study was to assess the pan-European reproducibility of the Food4Me food-frequency questionnaire (FFQ) in assessing the habitual diet of adults. METHODS: Participants from the Food4Me study, a 6-mo, Internet-based, randomized controlled trial of personalized nutrition conducted in the United Kingdom, Ireland, Spain, Netherlands, Germany, Greece, and Poland, were included. Screening and baseline data (both collected before commencement of the intervention) were used in the present analyses, and participants were included only if they completed FFQs at screening and at baseline within a 1-mo timeframe before the commencement of the intervention. Sociodemographic (e.g., sex and country) and lifestyle [e.g., body mass index (BMI, in kg/m(2)) and physical activity] characteristics were collected. Linear regression, correlation coefficients, concordance (percentage) in quartile classification, and Bland-Altman plots for daily intakes were used to assess reproducibility. RESULTS: In total, 567 participants (59% female), with a mean ± SD age of 38.7 ± 13.4 y and BMI of 25.4 ± 4.8, completed both FFQs within 1 mo (mean ± SD: 19.2 ± 6.2 d). Exact plus adjacent classification of total energy intake in participants was highest in Ireland (94%) and lowest in Poland (81%). Spearman correlation coefficients (ρ) in total energy intake between FFQs ranged from 0.50 for obese participants to 0.68 and 0.60 in normal-weight and overweight participants, respectively. Bland-Altman plots showed a mean difference between FFQs of 210 kcal/d, with the agreement deteriorating as energy intakes increased. There was little variation in reproducibility of total energy intakes between sex and age groups. CONCLUSIONS: The online Food4Me FFQ was shown to be reproducible across 7 European countries when administered within a 1-mo period to a large number of participants. The results support the utility of the online Food4Me FFQ as a reproducible tool across multiple European populations. This trial was registered at clinicaltrials.gov as NCT01530139.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Afforestation of agricultural land is increasing, partly because it is an important biological method for reducing the concentration of atmospheric CO2 and potentially mitigating climate change. Rainfall patterns are changing and prolonged dry periods are predicted for many regions of the world, including southern Australia. To accurately predict land-use change potential for mitigating climate change, we need to have a better understanding of how changes in land-use (i.e. afforestation of pastures) may change the soils response to prolonged dry periods. We present results of an incubation study characterising C and N dynamics and the microbial community composition in soil collected from two tree plantings and their adjacent pastures under a baseline and reduced frequency. While the concentration of soil C was similar in pasture and tree planting soils, heterotrophic respiration was significantly lower in soil from pastures than tree plantings. Although there was little difference in the composition of the soil microbial community among any of the soils or treatments, differences in N cycling could indicate a difference in microbial activity, which may explain the differences in heterotrophic respiration between pastures and tree plantings. Soils from pastures and tree plantings responded similarly to a reduction in wetting frequency, with a decrease in microbial biomass (measured as total PLFA), and a similar reduction in heterotrophic respiration from the soil. This suggests that the responses to changes in future wetting cycles may be less dependent on land-use type than expected.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Load frequency Control (LFC) is used for many years as part of Automatic Generation Control (AGC) in power system around the world. In a mixed power system, it is usual to find an area regulated by hydro generation interconnected to another area regulated by thermal generation or in combination of both. In the following study, performance of AGC for Thermal, Hydro and Thermal turbine based power system is examined, including how frequency bias setting influences AGC responseand inadvertent interchange. Control performance analysis of three area interconnected systems is simulated and studied through Matlab Simulink software. Integral square error and Integral time absolute error has been used as performance criterion. It is shown that integral timeabsolute error (ITAE) as performance index leads to faster optimization of controller gain.