947 resultados para whether time may be extended after order filed


Relevância:

100.00% 100.00%

Publicador:

Resumo:

For over two decades the issue of East Timor's right to self-determination has been a ‘prickly’ issue in Australian foreign policy. The invasion by Indonesian forces in 1975 was expected, as Australian policy-makers had been well informed of the events leading up to the punitive action being taken. Indeed, prior discussions involving the future of the territory were held between the Australian Prime Minister and the Indonesian President in 1974. In response to the events unfolding in the territory the Australian Labor Government at the time was presented with two policy options for dealing with the issue. The Department of Defence recommended the recognition of an independent East Timor; whereas the Department of Foreign Affairs proposed that Australia disengage itself as far as possible from the issue. The decision had ramifications for future policy considerations especially with changes in government. With the Department of Foreign Affairs option being the prevailing policy what were the essential ingredients that give explanation for the government's choice? It is important to note the existence of the continuity and cyclical nature of attitudes by Labor governments toward Indonesia before and after the invasion. To do so requires an analysis of the influence ‘Doc’ Evatt had in shaping any possible Labor tradition in foreign policy articulation. The support given by Evatt for the decolonisation of the Netherlands East Indies (Indonesia) gave rise to the development of a special relationship-so defined. Evidence of the effect Evatt had on future Labor governments may be found in the opinions of Gough Whitlam. In 1975 when he was Prime Minister, Whitlam felt the East Timor issue was merely the finalisation of Indonesia's decolonisation honouring Evatt's long held anti-colonialist tradition existing in the Australian Labor Party. The early predisposition toward Indonesia's cohesiveness surfaced again in the Hawke and Keating Labor governments of later years. It did not vary a great deal with changes in government The on-going commitment to preserving and strengthening the bilateral relationship meant Indonesia's territorial integrity became the focus of the Australian political elites’ regional foreign policy determinations. The actions taken by policy-makers served to promote the desire for a stable region ahead of independence claims of the East Timorese. From a realist perspective, the security dilemma for Australian policy-makers was how to best promote regional order and stability in the South East Asian region. The desire for regional cohesiveness and stability continues to drive Australian political elites to promote policies that gives a priority to the territorial integrity of regional states. Indonesia, in spite of its diversity, was only ever thought of as a cohesive unitary state and changes to its construct have rarely been countenanced. Australia's political elite justifications for this stance vacillate between strategic and economic considerations, ideological (anti-colonialism) to one of being a pragmatic response to international politics. The political elite argues the projection of power into the region is in Australia’s national interest. The policies from one government to the next necessarily see the national interest as being an apparent fixed feature of foreign policy. The persistent fear of invasion from the north traditionally motivated Australia's political elite to adopt a strategic realist policy that sought to ‘shore up’ the stability, strength and unity of Indonesia. The national interest was deemed to be at risk if support for East Timorese independence was given. The national interest though can involve more than just the security issue, and the political elite when dealing with East Timor assumed that they were acting in the common good. Questions that need to be addressed include determining what is the national interest in this context? What is the effect of a government invoking the national interest in debates over issues in foreign policy? And, who should participate in the debate? In an effort to answer these questions an analysis of how the ex-foreign affairs mandarin Richard Woolcott defines the national interest becomes crucial. Clearly, conflict in East Timor did have implications for the national interest. The invasion of East Timor by Indonesia had the potential to damage the relationship, but equally communist successes in 1975 in Indo-China raised Australia's regional security concerns. During the Cold War, the linking of communism to nationalism was driving the decision-making processes of the Australian policy-makers striving to come to grips with the strategic realities of a changing region. Because of this, did the constraints of world politics dominated by Cold War realities combined with domestic political disruption have anything to do with Australia's response? Certainly, Australia itself was experiencing a constitutional crisis in late 1975. The Senate had blocked supply and the Labor Government did not have the funds to govern. The Governor-General by dismissing the Labor Government finally resolved the impasse. What were the reactions of the two men charged with the responsibility of forming the caretaker government toward Indonesia's military action? And, could the crisis have prevented the Australian government from making a different response to the invasion? Importantly, and in terms of economic security, did the knowledge of oil and gas deposits thought to exist in the Timor Sea influence Australia's foreign policy? The search for oil and gas requires a stable political environment in which to operate. Therefore for exploration to continue in the Timor Sea Australia must have had a preferred political option and thoughts of with whom they preferred to negotiate. What was the extent of each government's cooperation and intervention in the oil and gas industry and could any involvement have influenced the Australian political elites’ attitude toward the prospect of an independent East Timor? Australia's subsequent de jure recognition that East Timor was part of Indonesia paved the way for the Timor Gap (Zone of Cooperation) Treaty signing in 1989. The signing underpinned Australia's acceptance of Indonesian sovereignty over East Timor. The outcome of the analysis of the issues that shaped Australia's foreign policy toward East Timor showed that the political elite became locked into an integration model, which was defended by successive governments. Moreover, they formed an almost reflexive defence of Indonesia both at the domestic and international level.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: Television viewing time is associated with obesity risk independent of leisure-time physical activity (LTPA). However,
it is unknown whether the relationship of TV viewing time with body mass index (BMI) is moderated by other domains of physical activity. Methods: A mail survey collected height;weight; TV viewing time; physical activity for transportation (habitual transport behavior; past week walking and bicycling), for recreation (LTPA), and in workplace; and sociodemographic variables in Adelaide, Australia. General linear models examined whether physical activity domains moderate the association between BMI and TV viewing time. Results: Analysis of the sample (N = 1408) found that TV time, habitual transport, and LTPA were independently associated with participant’s BMI. The interaction between TV time and habitual transport with BMI was significant, while that between TV time and LTPA was not. Subgroup analyses found that adjusted mean BMI was significantly higher for the high TV viewing category, compared with the low category,
among participants who were inactive and occasionally active in transport, but not among those who were regularly active. Conclusions: Habitual active transport appeared to moderate the relationship between TV viewing time and BMI. Obesity risk associated with prolonged TV viewing may be mitigated by regular active transport.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

OBJECTIVE We aimed to investigate whether the proportion of breastfeeding mothers in first-time parent groups influenced the likelihood of ceasing breastfeeding and whether this was independent of socioeconomic position.
METHODS Data were from 501 mothers (from 62 first-time parent groups initiated ~6 weeks after birth) who provided data at the baseline and mid-intervention assessments of the Melbourne Infant Feeding, Activity, and Nutrition Trial. Parent groups were divided into those in which ≤25% of mothers had ceased breastfeeding by 6 weeks (low-cessation groups) and those in which >25% had ceased by 6 weeks (high-cessation groups).
RESULTS With the exclusion of mothers who had already ceased breastfeeding by 6 weeks, the proportion of mothers who ceased breastfeeding between the time of parent group initiation (6 weeks) and 6 months was higher in high-cessation groups than in low-cessation groups (37.4% vs 21.7%; P = .001). After adjustment for maternal age, BMI, employment, and education and area-level socioeconomic position, membership in a group in which a large proportion of mothers had ceased breastfeeding by 6 weeks was strongly related to cessation of breastfeeding before 6 months (odds ratio: 2.1 [95% confidence interval: 1.3–3.3]).
CONCLUSIONS Attendance at parent groups where peers are breastfeeding infants of a similar age may have an important influence on the continuation of breastfeeding to 6 months. First-time parent groups or other similar groups may be an important setting in which to promote the continuation of breastfeeding.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Purpose: An ongoing concern with the evaluation of auditory processing disorders is the extent that assessment instruments are influenced by higher order cognitive functions. This study examined the relationship between verbal working memory and performance on the Test for Auditory Processing Disorders in Children--Revised (SCAN-C; Keith, 2000b) in children with specific language impairment (SLI) and typically developing (TD) children.

Method: Sixteen children with SLI and 16 TD children ages 8/4 to 11 years participated in the study. The children were presented with the SCAN-C and tests measuring verbal working memory.

Results:
Initial comparisons revealed that the SLI group obtained significantly lower scores than the TD group on the SCAN-C. However, after controlling for verbal working memory, significant differences between the 2 groups were no longer observed. Correlational analyses revealed that the composite score from the SCAN-C was related to all tests assessing verbal working memory.

Conclusions:
Performance on the SCAN-C may be related to working memory functioning. As a consequence, it is unclear whether difficulty on this task should be viewed as a problem with auditory processing or a problem with verbal working memory.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

It is known that the constant modulus (CM) property of the source signal can be exploited to blindly equalize time-invariant single-inputmultiple-output (SIMO) and finite-impulse-response (FIR) channels. However, the time-invariance assumption about the channel cannot be satisfied in several practical applications, e.g., mobile communication. In this paper, we show that, under some mild conditions, the CM criterion can be extended to the blind equalization of a time-varying channel that is described by the complex exponential basis expansion model (CE-BEM). Although several existing blind equalization methods that are based on the CE-BEM have to employ higher order statistics to estimate all nonzero channel pulsations, the CM-based method only needs to estimate one pulsation using second-order statistics, which yields better estimation results. It also relaxes the restriction on the source signal and is applicable to some classes of signals with which the existing methods cannot deal.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mammary explants can be hormonally stimulated to mimic the biochemical changes that occur during lactogenesis. Previous studies using mammary explants concluded that the addition of exogenous macromolecules were required for mammary epithelial cells to remain viable in culture. The present study examines the survival of mammary explants from the dairy cow using milk protein gene expression as a functional marker of lactation and cell viability. Mammary explants cultured from late pregnant cows mimicked lactogenesis and showed significantly elevated milk protein gene expression after 3 days of culture with lactogenic hormones. The subsequent removal of exogenous hormones from the media for 10 days resulted in the down-regulation of milk protein genes. During this time, the mammary explants remained hormone responsive, the alveolar architecture was maintained and the expression of milk protein genes was re-induced after a second challenge with lactogenic hormones. We report that a population of bovine mammary epithelial cells have an intrinsic capacity to remain viable and hormone responsive for extended periods in chemically defined media without any exogenous macromolecules. In addition, we found mammary explant viability was dependent on de novo protein and RNA synthesis. Global functional microarray analysis showed that differential expression of genes involved in energy production, immune responses, oxidative stress and apoptosis signalling might contribute to cell survival. As the decline in milk production in dairy cattle after peak lactation results in considerable economic loss, the identification of novel survival genes may be used as genetic markers for breeding programmes to improve lactational persistency in dairy cows.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background
Accelerometers have been used to determine the amount of time that children spend sedentary. However, as time spent sitting may be detrimental to health, research is needed to examine whether accelerometer sedentary cut-points reflect the amount of time children spend sitting. The aim of this study was to: a) examine agreement between ActiGraph (AG) cut-points for sedentary time and objectively-assessed periods of free-living sitting and sitting plus standing time using the activPAL (aP); and b) identify cut-points to determine time spent sitting and sitting plus standing.

Methods
Forty-eight children (54% boys) aged 8–12 years wore a waist-mounted AG and thigh-mounted aP for two consecutive school days (9–3:30 pm). AG data were analyzed using 17 cut-points between 50–850 counts·min−1 in 50 counts·min−1 increments to determine sedentary time during class-time, break time and school hours. Sitting and sitting plus standing time were obtained from the aP for these periods. Limits of agreement were computed to evaluate bias between AG50 to AG850 sedentary time and sitting and sitting plus standing time. Receiver Operator Characteristic (ROC) analyses identified AG cutpoints that maximized sensitivity and specificity for sitting and sitting plus standing time.

Results
The smallest mean bias between aP sitting time and AG sedentary time was AG150 for class time (3.8 minutes), AG50 for break time (−0.8 minutes), and AG100 for school hours (−5.2 minutes). For sitting plus standing time, the smallest bias was observed for AG850. ROC analyses revealed an optimal cut-point of 96 counts·min−1 (AUC = 0.75) for sitting time, which had acceptable sensitivity (71.7%) and specificity (67.8%). No optimal cut-point was obtained for sitting plus standing (AUC = 0.51).

Conclusions
Estimates of free-living sitting time in children during school hours can be obtained using an AG cut-point of 100 counts·min−1. Higher sedentary cut-points may capture both sitting and standing time.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background : There is an increased incidence of major depressive disorder (MDD) in individuals after myocardial infarction (MI), but the pathophysiological processes mediating this association are unclear. Our previous study demonstrated an increase in pro-apoptotic pathways in the myocardium and hippocampus in MDD, which was reversed by venlafaxine. This study aimed to attempt to confirm the effects of apoptosis vulnerability markers on the myocardium in a model of depression after myocardial infarction.

Methods :
Rats were divided into four groups: sham (N = 8), depression (N = 8, chronic mild unpredictable stress and separation were used in the depression group), MI (N = 13) and post-MI depression (N = 7). The rats in all four groups underwent the same open field and sucrose preference behavioral tests. Evan Blue staining was used to determine the area at risk of myocardial infarction in the left ventricle, and 2,3,5-triphenyl tetrazolium chloride (1.5% TTC) dye was used to detect the size of the myocardial infarction. The expression of bax and bcl-2 protein in the myocardium was investigated by immunohistochemistry, and the mRNA expression of bax, bcl-2 and caspase-3 in the myocardium was investigated by real time RT-PCR. Apoptosis was estimated in the myocardium by measuring the Bax:Bcl-2 ratio.

Results :
In the depression and post-MI depression rats, there were significantly decreased movements and total sucrose consumption, modeling behavioral deficits and an anhedonic-like state. In terms of myocardial infarction size, no difference was seen between the MI and post-MI depression groups. There was an up-regulated Bax:Bcl-2 ratio in the depression, MI and post-MI depression groups. Furthermore, in the latter group, there was a greater up-regulated Bax:Bcl-2 ratio. However, caspase-3 did not differ among the four groups.

Conclusions :
These results of this animal model suggest that active pro-apoptotic pathways may be involved in the nexus between myocardial infarction and depression. This mechanism may be germane to understanding this relationship in humans.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction: The motor and non-motor symptoms associated with idiopathic Parkinson’s disease (PD) may compromise the health-related quality of life (HRQOL) of some individuals living with this debilitating condition. Although growing evidence suggests that PD may be more prevalent in rural communities, there is little information about the life quality of these individuals. This study examines whether HRQOL ratings vary in relation to rural and metropolitan life settings.
Methods: An analytic cross-sectional study was conducted to compare the HRQOL of two separate samples of people with PD living in metropolitan Melbourne and rural Victoria. The metropolitan sample consisted of 210 individuals who had participated in the baseline assessment for an existing clinical trial. The rural sample comprised 24 participants who attended community-based rehabilitation programs and support groups in rural Victoria. Health-related quality of life was quantified using the Parkinson’s Disease Questionnaire-39 (PDQ-39).
Results:
The HRQOL of participants in rural Australia differed from individuals living in a large metropolitan city (p=0.025). Participants in rural Australia reported worse overall HRQOL, after controlling for differences in disease duration. Their overall HRQOL was lower than for city dwellers. Rural living was also found to be a significant negative predictor of HRQOL (β=0.14; 95% CI -1.27 to -0.08; p=0.027).
Conclusion:
The findings of this study suggest that some people with PD living in rural Victoria perceive their HRQOL to be relatively poor. In order to minimise the debilitating consequences of this disease, further studies examining the factors that may contribute to the HRQOL of individuals living in rural and remote areas are required.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The movements of 8 green turtles Chelonia mydas in Brazilian coastal waters were tracked using transmitters linked to the Argos system for periods of between 1 and 197 d. These were the first tracking data gathered on juveniles of this species in this important foraging ground. Information was integrated with that collected over a decade using traditional flipper-tagging methods at the same site. Both satellite telemetry and flipper tagging suggested that turtles undertook 1 of 3 general patterns of behaviour: pronounced long range movements (>100 km), moderate range movements (<100 km) or extended residence very close to the capture/release site. There seemed to be a general tendency for the turtles recaptured/tracked further afield to have been among the larger turtles captured. Satellite tracking of 5 turtles which moved from the release site showed that they moved through coastal waters; a factor which is likely to predispose migrating turtles to incidental capture as a result of the prevailing fishing methods in the region. The movements of the 3 turtles who travelled less than 100 km from the release site challenge previous ideas relating to home range in green turtles feeding in sea grass pastures. We hypothesise that there may be a fundamental difference in the pattern of habitat utilisation by larger green turtles depending on whether they are feeding on seagrass or macroalgae. Extended tracking of 2 small turtles which stayed near the release point showed that small juvenile turtles, whilst in residence in a particular feeding ground, can also exhibit high levels of site-fidelity with home ranges of the order of several square kilometers.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objective
The aim of this study was to examine whether frequency of park visitation was associated with time spent in various domains of physical activity among adults living in a disadvantaged neighbourhood of Victoria, Australia.

Methods
In 2009, participants (n = 319) self-reported park visitation and physical activity including: walking and cycling for transport, leisure-time walking, leisure-time moderate- to vigorous-intensity physical activity, and total physical activity.

Results
The mean number of park visits per week was 3.3 (SD = 3.8). Park visitation was associated with greater odds of engaging in high (as compared to low) amounts of transportation physical activity, leisure-time walking, leisure-time moderate- to vigorous-intensity physical activity (MVPA) and total physical activity. Each additional park visit per week was associated with 23% greater odds of being in the high category for transportation physical activity, 26% greater odds of engaging in high amounts of leisure-time walking, 11% greater odds of engaging in MVPA, and 40% greater odds of high total physical activity.

Conclusions
Acknowledging the cross-sectional study design, the findings suggest that park visitation may be an important predictor and/or destination for transportation and leisure-time walking and physical activity. Findings highlight the potentially important role of parks for physical activity.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background There are ongoing questions about whether unemployment has causal effects on suicide as this relationship may be confounded by past experiences of mental illness. The present review quantified the effects of adjustment for mental health on the relationship between unemployment and suicide. Findings were used to develop and interpret likely causal models of unemployment, mental health and suicide. Method A random-effects meta-analysis was conducted on five population-based cohort studies where temporal relationships could be clearly ascertained. Results Results of the meta-analysis showed that unemployment was associated with a significantly higher relative risk (RR) of suicide before adjustment for prior mental health [RR 1.58, 95% confidence interval (CI) 1.33–1.83]. After controlling for mental health, the RR of suicide following unemployment was reduced by approximately 37% (RR 1.15, 95% CI 1.00–1.30). Greater exposure to unemployment was associated with higher RR of suicide, and the pooled RR was higher for males than for females. Conclusions Plausible interpretations of likely pathways between unemployment and suicide are complex and difficult to validate given the poor delineation of associations over time and analytic rationale for confounder adjustment evident in the revised literature. Future research would be strengthened by explicit articulation of temporal relationships and causal assumptions. This would be complemented by longitudinal study designs suitable to assess potential confounders, mediators and effect modifiers influencing the relationship between unemployment and suicide.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The resurrection grass Sporobolus stapfianus Gandoger can rapidly recover from extended periods of time in the desiccated state (water potential equilibrated to 2% relative humidity) (Gaff and Ellis, Bothalia 11:305–308 1974; Gaff and Loveys, Transactions of the Malaysian Society of Plant Physiology 3:286–287 1993). Physiological studies have been conducted in S. stapfianus to investigate the responses utilised by these desiccation-tolerant plants to cope with severe water-deficit. In a number of instances, more recent gene expression analyses in S. stapfianus have shed light on the molecular and cellular mechanisms mediating these responses. S. stapfianus is a versatile research tool for investigating desiccation-tolerance in vegetative grass tissue, with several useful characteristics for differentiating desiccation-tolerance adaptive genes from the many dehydration-responsive genes present in plants. A number of genes orthologous to those isolated from dehydrating S. stapfianus have been successfully used to enhance drought and salt tolerance in model plants as well as important crop species. In addition to the ability to desiccate and rehydrate successfully, the survival of resurrection plants in regions experiencing short sporadic rainfall events may depend substantially on the ability to tightly down-regulate cell division and cell wall loosening activities with decreasing water availability and then grow rapidly after rainfall while water is plentiful. Hence, an analysis of gene transcripts present in the desiccated tissue of resurrection plants may reveal important growth-related genes. Recent findings support the proposition that, as well as being a versatile model for devising strategies for protecting plants from water-loss, resurrection plants may be a very useful tool for pinpointing genes to target for enhancing growth rate and biomass production.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

RICA commissioned Deakin University to “establish whether response rates are in decline in the Australian market research industry and to identify, as far as possible, the reasons for these declines if they exist. This is likely to involve a review of previous research, a literature review and collection of data on response rates provided on a confidential basis and with the assistance of AMSRO to facilitate data provision.”

Attempts were made to contact all listed market research companies in Australia, including all major internet panel companies. While industry co-operation was not high with the study, sufficient data was provided to depict current response rates and to show how they had declined over time. Because of the low contactability issues, this Report proposes the use of better methods to compute the reliability of survey estimates by taking account of past survey results.

The literature review revealed a wealth of recent studies, with the main emphasis being on studies of telephone and internet surveys. This review of the research produced 34 evidence-based guidelines for social researchers. While some of these reflect current practice, the emergence of the internet as the main survey method raises a number of disclosure and sampling issues. Esomar (2012) has produced 28 issues to be raised with providers, which sets the basis for good industry practice. This suggests an opportunity for the industry to adopt these standards as its own and to conduct training courses for major clients and suppliers. There are many panel providers, some of whom are not AMSRO members. AMSRO may need to examine what role it can play in mandating or encouraging adherence to these standards as a way of promoting the industry.

Talks with key industry people, as well as the literature, have revealed the importance of blended surveys, where multiple contact and response mechanisms are used. Particularly where an internet panel is used as one source, this poses representativeness and weighting issues which are difficult to resolve. The Report recommends that where blended survey methods are used, measures be taken to measure contactability in the other contact media, along with more sophisticated weighting schemes. The industry should examine its training courses to ensure that industry expertise keeps pace with these developments.
Summary of Results

The results focus on two main collection methods – the telephone and the internet. As far as the telephone is concerned response rates have been in a gradual decline the last decade. This outcome is hard to detect because the data show considerable fluctuations from one survey wave to the next. Among cold-calling surveys, telephone response rates are typically below 10%, for a range of topics and survey types. Co-operation rates, (the ratio of obtained interviews to refusals) are typically below 0.2 (that is below one interview to five refusals). Telephone interviews with clients have a higher response rate – typically above 20% with co-operation rates above 1.0. It would appear that some topics, such as financial services, may induce a lower level of co-operation. Government sponsored surveys have higher response rates, at times over 50%, but even here a sharp decline in response rates over time for one long running monitor was observed. Co-operation rates were also higher in government sponsored surveys.

One long data series from a telephone omnibus suggested that the “Do Not Call Register” which began in May, 2007 had some positive effects for the industry. Initially there was a spike in both response rates and co-operation. Although this was relatively short-lived, response rates thereafter declined more slowly and co-operation rates were somewhat higher and remained stable. These conclusions should be regarded as tentative as more data series would really be necessary to see if similar trends occurred elsewhere.

As far as the internet is concerned, panel response rates are around the 20% mark and appear to be relatively stable over the last few years. In this case, the gross response rate is the number of interviews divided by the number of invitations sent. As the number of invitations may be a function of the need to fill a survey quickly, it should be considered a gross indicator of response. In order to capture this phenomenon, a further measure has been devised, termed the “attempt rate” which measures the percentage of people who attempt to participate once sent the invitation. The available data suggests that it is relatively stable. However, it is also somewhat susceptible to the time the survey was left open. Finally, a co-operation rate was also calculated. It measures the ratio of completed to terminated interviews, typically at least five interviews to each termination, but often much higher. This measure is not directly comparable with the co-operation rate in telephone surveys because it cannot take account of the number of eligible people on the panel who open the invitation, see the company doing the survey or its length and decide not to take the survey. For internet client studies, response rates were typically somewhat higher than shown for the panels, but there was marked variability.

There was only one study provided of intercept interviews. It showed response rates of over 60% and co-operation rates of nearly 2 interviews per refusal. A strength and a weakness of intercept interviewing is the ability to be selective in who is asked to participate. As for mail, one government sponsored mail survey from 2010 is reported, with a response rate over 50%. The previous review contains more data, as mail appears to be infrequently used within the industry for commercial surveys.

While surveys remain a major and highly effective tool for the industry and its clients, issues with contactability and co-operation mean that even closer attention is needed to survey design, sampling, weighting and analysis than was previously the case.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: Although the pressure flow theory is widely accepted for the transport of photoassimilates in phloem sieve elements, it still requires strong experimental validation. One reason for that is the lack of a precise method for measuring the real-time phloem turgor pressure from the sink tissues, especially in tree trunks. Results: Taking the merits of Hevea brasiliensis, a novel phloem turgor pressure probe based on the state of the art cell pressure probe was developed. Our field measurements showed that the phloem turgor pressure probe can sensitively measure the real-time variation of phloem turgor pressure in H. brasiliensis but the calculation of phloem turgor pressure with xylem tension, xylem sap osmotic potential and phloem sap osmotic potential will under-estimate it. The measured phloem turgor pressure gradient in H. brasiliensis is contrary to the Münch theory. The phloem turgor pressure of H. brasiliensis varied from 8-12 bar as a consequence of water withdrawal from transpiration. Tapping could result in a sharp decrease of phloem turgor pressure followed by a recovery from 8-45 min after the tapping. The recovery of phloem turgor pressure after tapping and its change with xylem sap flow suggest the importance of phloem water relationship in the phloem turgor pressure regulation. Conclusion: The phloem turgor pressure probe is a reliable technique for measuring the real-time variation of phloem turgor pressures in H. brasiliensis. The technique could probably be extended to the accurate measurement of phloem turgor pressure in other woody plants which is essential to test the Münch theory and to investigate the phloem water relationship and turgor pressure regulation. © 2014 An et al.