76 resultados para 070301 Agro-ecosystem Function and Prediction

em Deakin Research Online - Australia


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Progression of disease caused by the plant pathogen Phytophthora cinnamomi was correlated to rainfall events and resulted in a loss of plant species diversity in heathland vegetation at Anglesea, Victoria. Lower captures of small mammals were recorded in diseased areas. Management of disease using the chemical phosphite was also evaluated.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Exotic flora, particularly weeds, are renowned for out-competing and displacing native flora, consequently affecting native fauna and pollinator relationships. Nonetheless, it stands to reason that weeds must provide some compensatory ecological value. This study assessed whether weeds are friend or foe to ecosystem function by considering the quality and quantity of pollen offered by widespread weeds in Australian ecosystems. Using the Honeybee Apis mellifera as a case study, and information derived from highly experienced commercial apiarists, we determined that 32 exotic plants are important pollen sources. Most species offered high to very high quality pollen. Pollen quality varied temporally, spatially and infraspecifically. Fifteen species were considered more beneficial to A. mellifera than others; only seven species were considered less beneficial. Thus, exotic flora contribute pollen resources that are valuable to maintain ecosystem function, particularly at times when flowering native species are few.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

By emphasizing Australian carnivores as exemplars of flesh-eaters in other parts of the world, this book will be an important reference for researchers, wildlife managers and students worldwide.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Prediction of more than four ears in a cup drawing process can be successfully achieved by considering r-value and stress directionalities. Yld2004-18p based on associated flow rule and Yld2000-2D based on non-associated flow rule are the examples. The former, however, is more costly in terms of computational efficiency than the latter. In this work, an anisotropic constitutive model based on non-associated flow rule which combines two different functions, Hill (1948) and Yld2000-2d, is implemented to a user defined material model. The accuracy of the anisotropic directionalities (yield stresses and plastic strain ratios) is evaluated. Simulation of a mini-die cup drawing with a body stock alloy predicted eight ears, in good agreement with the experimental results. The use of Hill (1948) model for the yield function and Yld2000-2d for plastic potential under the framework of non-associated flow rule led to accurate prediction of up to eight ears at the lower computational cost.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Artificial Neural Networks (ANN) performance depends on network topology, activation function, behaviors of data, suitable synapse's values and learning algorithms. Many existing works used different learning algorithms to train ANN for getting high performance. Artificial Bee Colony (ABC) algorithm is one of the latest successfully Swarm Intelligence based technique for training Multilayer Perceptron (MLP). Normally Gbest Guided Artificial Bee Colony (GGABC) algorithm has strong exploitation process for solving mathematical problems, however the poor exploration creates problems like slow convergence and trapping in local minima. In this paper, the Improved Gbest Guided Artificial Bee Colony (IGGABC) algorithm is proposed for finding global optima. The proposed IGGABC algorithm has strong exploitation and exploration processes. The experimental results show that IGGABC algorithm performs better than that standard GGABC, BP and ABC algorithms for Boolean data classification and time-series prediction tasks.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Summary: The composition of species pools can vary in space and time. While many studies are focused on understanding which factors influence the make-up of species pools, the question to which degree biogeographic variation in species composition propagates to biogeographic variation in ecological function is rarely examined. If different local species assemblages operate in ways that maintain specific ecological processes across continents, they can be regarded as functionally equivalent. Alternatively, variation in species assemblages might result in the loss of ecological function if different species fulfil different functions, and thereby fail to maintain the ecological process. Here, we test whether ecological function is affected by differences in the composition of species pools across a continental scale, comparing a tropical with a temperate pool. The model systems are assemblages of vertebrates foraging on ocean beaches, and the ecological function of interest is the consumption of wave-cast carrion, a pivotal process in sandy shore ecosystems. We placed fish carcasses (n = 179) at the beach-dune interface, monitored by motion-triggered cameras to record scavengers and quantify the detection and removal of carrion. Scavenging function was measured on sandy beaches in two distinct biogeographic regions of Australia: tropical north Queensland and temperate Victoria. The composition of scavenging assemblages on sandy beaches varied significantly across the study domain. Raptors dominated in the tropics, while invasive red foxes were prominent in temperate assemblages. Notwithstanding the significant biogeographic change in species composition, ecological function - as indexed by carcass detection and removal - was maintained, suggesting strong functional replacement at the continental scale. Species pools of vertebrate scavengers that are assembled from taxonomically distinct groups (birds vs. mammals) and located in distinct climatic regions (temperate vs. tropical) can maintain an ecological process via replacement of species with comparable functional traits.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aim of this study was to investigate age, menopausal status, and the male partner's sexual function on the sexual function of the menopausal woman. Sexual functioning of 304 women (120 premenopausal, 76 perimenopausal, 108 postmenopausal) aged between 35 and 65 years from a community sample was investigated. Multiple regression analyses found that sexual satisfaction within the relationship was better predicted by age group than by menopausal status. Younger women were more likely to be satisfied with their sexual relationship than older women. Age group was also a better predictor than menopausal status of current frequency of intercourse, with younger women being likely to have more frequent intercourse than older women. Whether a female respondent had experienced a sexual dysfunction was better predicted by menopausal status than by age. Women who were menopausal were more likely to report a sexual problem such as lack of sexual interest, poor lubrication, and failure to have an orgasm. However, age group appeared to be a better predictor of whether the male partner had experienced a sexual dysfunction. Older men were more likely to have experienced failure to have an erection, for example. The findings of this study indicate that age and the sexual function of the partner are important factors to take into consideration when investigating the sexual function of the menopausal woman.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Wilson disease is an autosomal recessive copper transport disorder resulting from defective biliary excretion of copper and subsequent hepatic copper accumulation and liver failure if not treated. The disease is caused by mutations in the ATP7B (WND) gene, which is expressed predominantly in the liver and encodes a copper-transporting P-type ATPase that is structurally and functionally similar to the Menkes protein (MNK), which is defective in the X-linked copper transport disorder Menkes disease. The toxic milk (tx) mouse has a clinical phenotype similar to Wilson disease patients and, recently, the tx mutation within the murine WND homologue (Wnd) of this mouse was identified, establishing it as an animal model for Wilson disease. In this study, cDNA constructs encoding the wild-type (Wnd-wt) and mutant (Wnd-tx) Wilson proteins (Wnd) were generated and expressed in Chinese hamster ovary (CHO) cells. The tx mutation disrupted the copper-induced relocalization of Wnd in CHO cells and abrogated Wnd-mediated copper resistance of transfected CHO cells. In addition, co-localization experiments demonstrated that while Wnd and MNK are located in the trans-Golgi network in basal copper conditions, with elevated copper, these proteins are sorted to different destinations within the same cell. Ultrastructural studies showed that with elevated copper levels, Wnd accumulated in large multi-vesicular structures resembling late endosomes that may represent a novel compartment for copper transport. The data presented provide further support for a relationship between copper transport activity and the copper-induced relocalization response of mammalian copper ATPases, and an explanation at a molecular level for the observed phenotype of tx mice

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Consumption of some dietary fibres may benefit bowel health; however, the effect of Australian sweet lupin (Lupinus angustifolius) kernel fibre (LKFibre) is unknown. The present study examined the effect of a high-fibre diet containing LKFibre on bowel function and faecal putative risk factors for colon cancer compared to a control diet without LKFibre. Thirty-eight free-living, healthy men consumed an LKFibre and a control diet for 1 month each in a single-blind, randomized, crossover study. Depending on subject energy intake, the LKFibre diet was designed to provide 17–30 g/d fibre (in experimental foods) above that of the control diet. Bowel function self-perception, frequency of defecation, transit time, faecal output, pH and moisture, faecal levels of SCFA and ammonia, and faecal bacterial [ß]-glucuronidase activity were assessed. In comparison to the control diet, the LKFibre diet increased frequency of defecation by 0·13 events/d (P = 0·047), increased faecal output by 21 % (P = 0·020) and increased faecal moisture content by 1·6 % units (P = 0·027), whilst decreasing transit time by 17 % (P = 0·012) and decreasing faecal pH by 0·26 units (P < 0·001). Faecal butyrate concentration was increased by 16 % (P = 0·006), butyrate output was increased by 40 % (P = 0·002) and [ß]-glucuronidase activity was lowered by 1·4 µmol/h per g wet faeces compared to the control diet (P < 0·001). Addition of LKFibre to the diet incorporated into food products improved some markers of healthy bowel function and colon cancer risk in men.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ecosystem services are necessary, yet not sufficient for human well-being (however defined). Insufficient access to the ecosystem provisioning service of food is a particularly important factor in the loss of human well-being, but all ecosystem services contribute in some way to well-being. Although perhaps long obvious to ecologists, the links between ecosystems and aspects of human well-being, including health, have been less well understood among the social science community. This situation may now be starting to change, thanks in part to the Millennium Ecosystem Assessment (MA). Causality between ecosystem services and well-being is bidirectional; it is increasingly clear that functioning societies can protect or enhance ecosystem services, and accordingly, that societies with impaired well-being (best documented in the case of chronic diseases such as malaria and HIV/AIDS) can also experience a related decline in ecosystem services.

The future state of human well-being and of ecosystem services is more than the co-evolution of these two fundamental elements. Human well-being also depends, critically, upon the human institutions that govern relationships between human individuals and groups, and also between humans and ecosystem services.

The scenarios working group of the MA found that human well-being is highest in the Global Orchestration scenario, which assumes the fastest evolution of beneficial institutions, and is lowest in the Order from Strength scenario. Human well-being was found to be intermediate in the other two scenarios (Adapting Mosaic and Techno-Garden) even though these scenarios share a much greater recognition of the importance of ecosystem services to human well-being.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Since the observations in the 1960s that granulocyte-colony stimulating factor (G-CSF) stimulated the proliferation of granulocytic cells in semisolid cultures of bone marrow cells, G-CSF has established itself as a useful clinical agent for increasing levels of neutrophilic granulocytes. However, these early findings did not firmly establish whether G-CSF is a genuine regulator of granulocyte formation under normal physiological conditions or rather acts as an emergency regulator, playing an important role only under stress conditions. The advent of <gene-knockout technology> has allowed us to evaluate these questions in a physiological setting through analysis of mice with a targeted mutation of G-CSF or its receptor, while the development of relevant cell models has enabled us to dissect the molecular basis of G-CSF action. This review discusses our current state of knowledge regarding the role of G-CSF in granulopoiesis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

To highlight the salient psychological and interpersonal issues contributing to sexual health and dysfunction; to offer a four-tiered paradigm for understanding the evolution and maintenance of sexual symptoms; and to offer recommendations for clinical management and research.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction. No previous population-based studies have used validated instruments to measure female sexual dysfunction (FSD) in Australian women across a broad age range.
Aim. To estimate prevalence and explore factors associated with the  components of FSD.
Main Outcome Measures. Sexual Function Questionnaire measured low sexual function. Female Sexual Distress Scale measured sexual distress.
Methods. Multivariate analysis of postal survey data from a random sample of 356 women aged 20–70 years.
Results. Low desire was more likely to occur in women in relationships for 20–29 years (odds ratio 3.7, 95% confidence intervals 1.1–12.8) and less likely in women reporting greater satisfaction with their partner as a lover (0.3, 0.1–0.9) or who placed greater importance on sex (0.1, 0.03–0.3). Low genital arousal was more likely among women who were perimenopausal (4.4, 1.2–15.7), postmenopausal (5.3, 1.6–17.7), or depressed (2.5, 1.1–5.3), and was less likely in women taking hormone therapy (0.2, 0.04–0.7), more educated (0.5, 0.3–0.96), in their 30s (0.2, 0.1–0.7) or 40s (0.2, 0.1–0.7), or placed greater importance on sex (0.2, 0.05–0.5). Low orgasmic function was less likely in women who were in their 30s (0.3, 0.1–0.8) or who placed greater importance on sex (0.3, 0.1–0.7). Sexual distress was positively associated with depression (3.1, 1.2–7.8) and was inversely associated with better communication of sexual needs (0.2, 0.05–0.5). Results were adjusted for other covariates including age, psychological, socioeconomic, physiological, and relationship factors.
Conclusions. Relationship factors were more important to low desire than age or menopause, whereas physiological and psychological factors were more important to low genital arousal and low orgasmic function than relationship factors. Sexual distress was associated with both psychological and relationship factors.