718 resultados para life resistance
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Rice ragged stunt virus (RRSV) is an important pathogen of rice affecting its cultivation in South and South East Asia. An approach based on pathogen derived resistance (PDR) was used to produce RRSV resistant rice cultivars. Sequences from the coding region of RRSV genome segments 7 and 10 (non-structural genes), and 5, 8 and 9 (structural genes) were placed in sense or antisense orientation behind the plant expression promoters CaMV35S, RolC, Ubil, Actl and RBTV. Rice cultivars Taipei 309 and Chinsurah Boro II were transformed by biolistic and/or Agrobacterium-mediated delivery of one or more of these PDR gene constructs. A large number of transgenic lines were produced from calli derived from mature or immature embryos, co-bombarded with the marker gene hph encoding hygromycin resistance and RRSV PDR genes or co-cultivated with strains having the binary vector containing these two genes. Both Mendelian and non-Mendelian segregations were observed in transgenic progeny, especially with transgenic lines produced by biolistics. Preliminary tests conducted in China on selected transgenic lines indicate that plants with RRSV segment 5 antisense PDR gene confer RRSV resistance.
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The Yd2 gene for “resistance” to barley yellow dwarf virus (BYDV) has been widely used in barley (Hordeum vulgare). We have tested Australian isolates of BYDV of varying severity against barley genotypes with and without the Yd2 gene and report here a positive relationship between symptoms and virus levels determined by ELISA. Cultivar Shannon is the result of backcrossing the resistant line CI 3208 to cultivar Proctor, a susceptible line. It appears to be intermediate in reaction to BYDV between Proctor and CI 3208, although it carries the major gene, Yd2. Unlike the whole plant studies, no significant differences were observed with regard to the ability of protoplasts derived from these various genotypes to support BYDV replication. It is therefore demonstrated for the first time that the Yd2 gene is not among the small number of resistance genes which are effective against virus replication in isolated protoplasts.
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Efficient transformation of barley cv. Schooner was achieved using Agrobacterium delivery, hygromycin or bialaphos selection and embryogenic callus. Using this system, transgenic plants were generated that contained either the green fluorescent protein gene, or transgenes derived from barley yellow dwarf (BYDV) and cereal yellow dwarf (CYDV) viruses. Many of these plants contained 1-3 transgene copies that were inherited in a simple Mendelian manner. Some plants containing BYDV and/or CYDV derived transgenes showed reduced virus symptoms and rates of viral replication when challenged with the appropriate virus. The ability to transform Schooner is a significant advance for the Australian barley industry, as this elite malting variety is, and has for the last 15 years been, the most widely grown barley variety in eastern Australia.
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On occasion, virus-derived transgenes in plants can be poorly expressed and yet provide excellent virus resistance, and transgene constructs designed to supplement the expression of endogenous genes can have the effect of co-suppressing themselves and the endogenous genes. These two phenomena appear to result from the same post-transcriptional silencing mechanism, which operates by targeted-RNA degradation. Recent research into RNA-mediated virus resistance and co-suppression has provided insights into the interactions between plant viruses and their hosts, and spawned several models to explain the phenomenon.
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A very simple leaf assay is described that rapidly and reliably identifies transgenic plants expressing the hygromycin resistance gene, hph or the phosphinothricin resistance gene, bar. Leaf tips were cut from plants propagated either in the glasshouse or in tissue culture and the cut surface embedded in solid medium containing the appropriate selective agent. Non-transgenic barley or rice leaf tips had noticeable symptoms of either bleaching or necrosis after three days on the medium and were completely bleached or necrotic after one week. Transgenic leaf tips remained green and healthy over this period. This gave unambiguous discrimination between transgenic and non-transgenic plants. The leaf assay was also effective for dicot plants tested (tobacco and peas).
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BACKGROUND: Despite advancements in our understanding of the importance of stress reduction in achieving good health, we still only have limited insight into the impact of stress on cellular function. Recent studies have suggested that exposure to prolonged psychological stress may alter an individual's physiological responses, and contribute to morbidity and mortality. This paper presents an overview of the study protocol we are using to examine the impact of life stressors on lifestyle factors, health-related quality of life and novel and established biomarkers of stress in midlife and older Australian women.The primary aim of this study is to explore the links between chronic psychological stress on both subjective and objective health markers in midlife and older Australian women. The study examines the extent to which exposure frightening, upsetting or stressful events such as natural disasters, illness or death of a relative, miscarriage and relationship conflict is correlated with a variety of objective and subjective health markers.Methods/design: This study is embedded within the longitudinal Healthy Aging of Women's study which has collected data from midlife and older Australian women at 5 yearly intervals since 2001, and uses the Allostastic model of women's health by Groer and colleagues in 2010. The current study expands the focus of the HOW study and will assess the impact of life stressors on quality of life and clinical biomarkers in midlife and older Australian women to explain the impact of chronic psychological stress in women. DISCUSSION: The proposed study hypothesizes that women are at increased risk of exposure to multiple or repeated stressors, some being unique to women, and the frequency and chronicity of stressors increases women's risk of adverse health outcomes. This study aims to further our understanding of the relationships between stressful life experiences, perceived quality of life, stress biomarkers, chronic illness, and health status in women.
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Editorial paper
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Background Physiotherapists are a professional group with a high rate of attrition and at high risk of musculoskeletal disorders. The purpose of this investigation was to examine the physical activity levels and health-related quality of life of physiotherapists working in metropolitan clinical settings in an Australian hospital and health service. It was hypothesized that practicing physiotherapists would report excellent health-related quality of life and would already be physically active. Such a finding would add weight to a claim that general physical activity conditioning strategies may not be useful for preventing musculoskeletal disorders among active healthy physiotherapists, but rather, future investigations should focus on the development and evaluation of role specific conditioning strategies. Methods A questionnaire was completed by 44 physiotherapists from three inpatient units and three ambulatory clinics (63.7% response rate). Physical activity levels were reported using the Active Australia Survey. Health-related quality of life was examined using the EQ-5D instrument. Physical activity and EQ-5D data were examined using conventional descriptive statistics; with domain responses for the EQ-5D presented in a frequency histogram. Results The majority of physiotherapists in this sample were younger than 30 years of age (n = 25, 56.8%) consistent with the presence of a high attrition rate. Almost all respondents exceeded minimum recommended physical activity guidelines (n = 40, 90.9%). Overall the respondents engaged in more vigorous physical activity (median = 180 minutes) and walking (median = 135 minutes) than moderate exercise (median = 35 minutes) each week. Thirty-seven (84.1%) participants reported no pain or discomfort impacting their health-related quality of life, with most (n = 35,79.5%) being in full health. Conclusions Physical-conditioning based interventions for the prevention of musculoskeletal disorders among practicing physiotherapists may be better targeted to role or task specific conditioning rather than general physical conditioning among this physically active population. It is plausible that an inherent attrition of physiotherapists may occur among those not as active or healthy as therapists who cope with the physical demands of clinical practice. Extrapolation of findings from this study may be limited due to the sample characteristics. However, this investigation addressed the study objectives and has provided a foundation for larger scale longitudinal investigations in this field.
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In particle-strengthened metallic alloys, fatigue damage incubates at inclusion particles near the surface or at the change of geometries. Micromechanical simulation of inclusions such that the fatigue damage incubation mechanisms can be categorized. As micro-plasticity gradient field around different inclusions is different, a novel concept for nonlocal evaluation of micro-plasticity intensity is introduced. The effects of void aspects ration and spatial distributions are quantified for fatigue incubation life in the high-cycle fatigue regime. At last, these effects are integrated based on the statistical facts of inclusions to predict the fatigue life of structural components.
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In many interventions that are based on an exercise program intended to induce weight loss, the mean weight loss observed is modest and sometimes far less than what the individual expected. The individual responses are also widely variable, with some individuals losing a substantial amount of weight, others maintaining weight, and a few actually gaining weight. The media have focused on the subpopulation that loses little weight, contributing to a public perception that exercise has limited utility to cause weight loss. The purpose of the symposium was to present recent, novel data that help explain how compensatory behaviors contribute to a wide discrepancy in exercise-induced weight loss. The presentations provide evidence that some individuals adopt compensatory behaviors, that is, increased energy intake and/or reduced activity, that offset the exercise energy expenditure and limit weight loss. The challenge for both scientists and clinicians is to develop effective tools to identify which individuals are susceptible to such behaviors and to develop strategies to minimize their effect.
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The aim of this qualitative study was to explore key positive and negative factors that impact on grief resolution and health outcomes of caregivers who were caring, or had cared, for a family member with dementia who had died. The study was a scoping study and involved face-to-face interviews with these family caregivers (N ¼ 13). Results indicated a complex interaction of issues (many unique to dementia caregiving) which in different combinations acted as protective or risk factors for caregiver outcomes. Interaction of individual characteristics, role appraisal, value of intrinsic and extrinsic resources, and experiences with health professionals during the caregiving period and around the death of their relative were shown to have the most influence on caregiver outcomes. Psychological resilience and satisfaction with caregiving were protective against negative outcomes while unresolved grief was a risk factor. These findings highlight the potential benefits of multicomponent, holistic dementia caregiver interventions.
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The reliable operation of distribution systems is critically dependent on detailed understanding of load impacts on distribution transformer insulation systems. This paper estimates the impact of rooftop photovoltaic (PV) generation on a typical 200-kVA, 22/0.415-kV distribution transformer life under different operating conditions. This transformer supplies a suburban area with a high penetration of roof top photovoltaic systems. The transformer loads and the phase distribution of the PV systems are significantly unbalanced. Oil and hot-spot temperature and remnant life of distribution transformer under different PV and balance scenarios are calculated. It is shown that PV can significantly extend the transformer life.
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Australia’s mining boom Global demand for minerals and energy products has fuelled Australia’s recent resources boom and has led to the rapid expansion of mining projects not only in remote locations but increasingly in settled traditionally agricultural rural areas. A fundamental shift has also occurred in the provisioning of skilled and semi-skilled workers. The huge acceleration in industry demand for labour has been accompanied by the entrenchment of workforce arrangements largely dependent on fly-in, fly-out (FIFO) and drive–in, drive–out (DIDO) non-resident workers (NRWs). While NRWs are working away from their homes, they are usually accommodated in work camps or ‘villages’ for the duration of their work cycle which are normally comprised of many consecutive days of 12-hour day- and night-shifts. The health effects of this form of employment and the accompanying lifestyle is increasingly becoming contentious. Impacts on personal wellness, wellbeing and quality of life essentially remain under-researched and thus misunderstood. Sodexo in Australia Sodexo began operations in Australia in 1982, and has since become a leader in providing Quality of Life (QOL) services to businesses across the country. The 6,000 Australian employees are part of a global Sodexo team of 413,000 people. Sodexo in Australia designs, delivers and manages on-site their QOL services at 320 diverse site locations, including remote sites. Sodexo operates in a range of sectors, including the mining industry. Service plans are tailored to suit the individual needs of organisations. Sodexo Remote Sites has previously conducted unpublished research among mining workers in Australia. The results highlighted needs and expectations of Australian mining workers. Main insights about workers’ requirements were directed towards: • contacts with closest; • warm rest time around proper and varied meals; • additional services to help them better enjoy their life onsite and/or make the most of it; • organise their transportation; • promote community living; and • finding balance between professional and personal life. The brief for this current research is aimed at building upon this knowledge. Research brief Expectations for quality of life and wellness and wellbeing services are increasing dramatically. It's getting costlier and more difficult to retain valuable employees. This is particularly the case in the Australian mining sector. Given the level of interest in ensuring healthy workplaces in Australia, Sodexo has commissioned QUT to conduct a literature review. The objectives as specified by Sodexo are: Objective 1: To define the concepts of wellness and wellbeing and quality of life in Australia Objective 2: To examine how wellness and wellbeing are developed within organisations in Australia and how they impact on employee and organizational performance. More specifically, to review the literature that could be sourced about: • challenges of the mining environment; • the mining lifestyle – implications for health, wellness and daily life; • personal health and wellness of Australian mining workers; • factors affecting health in mines and perceived support for health and wellness; and • the impact of employer investment in health on perceptions and behaviour of employees. Objective 3: To determine what impact employee wellness and well-being has on the performance of mining workers. More specifically, to review the literature that could be sourced about: • impact of obesity, alcohol, tobacco use on companies; and • links between employee engagement and satisfaction and company productivity. Accordingly this review has attempted to ascertain what factors an organisation should focus on in order to reduce absenteeism and turnover and increase commitment, satisfaction, safety and productivity, with specific reference to the mining industry in Australia. The structure of the report aligns with the stated objectives in that each of the first three parts address an objective. Part IV summarises prominent issues that have arisen and offers some concluding observations and comments.