908 resultados para Perry, Lowell
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Agricultural systems models worldwide are increasingly being used to explore options and solutions for the food security, climate change adaptation and mitigation and carbon trading problem domains. APSIM (Agricultural Production Systems sIMulator) is one such model that continues to be applied and adapted to this challenging research agenda. From its inception twenty years ago, APSIM has evolved into a framework containing many of the key models required to explore changes in agricultural landscapes with capability ranging from simulation of gene expression through to multi-field farms and beyond. Keating et al. (2003) described many of the fundamental attributes of APSIM in detail. Much has changed in the last decade, and the APSIM community has been exploring novel scientific domains and utilising software developments in social media, web and mobile applications to provide simulation tools adapted to new demands. This paper updates the earlier work by Keating et al. (2003) and chronicles the changing external challenges and opportunities being placed on APSIM during the last decade. It also explores and discusses how APSIM has been evolving to a “next generation” framework with improved features and capabilities that allow its use in many diverse topics.
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Breaches of biosecurity, leading to incursions by invasive species, have the potential to cause substantial economic, social and environmental losses, including drastic reduction in biodiversity. It is argued that improving biosecurity reduces risk to biodiversity, while maintaining stable ecosystems through biodiversity can be a safeguard against biosecurity breaches. The global costs of invasive alien species (IAS) have been estimated at around US$350 billion, while alien invertebrate and vertebrate pests and weeds are estimated to cost Australia at least $7 billion a year. A striking, current, example is the incursion by Myrtle Rust (Puccinia psidii) an organism which can infect all members of the Myrtaceae, the most important family in the Australian flora. Myrtle rust was first detected on a property on the central coast of New South Wales in late April 2010. Two years later the disease has been detected in numerous locations in Queensland and New South Wales ranging from commercial plant nurseries and public amenities to large areas of bushland. This particular breach of biosecurity will, inevitably, diminish biodiversity of flora and fauna over large areas of the continent. Integrated pest management (IPM), an enrichment of diversity in managing invasive and other pest species, offers the best opportunity to address problems such as these. Australia's response to increasing biosecurity risk is comprehensive and includes national networking of scientists engaged in a complex program of biosecurity research and development, including studies of IPM. This network is being enhanced by the development of international linkages.
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- Objective To evaluate dietary intake impact outcomes up to 3.5 years after the NOURISH early feeding intervention (concealed allocation, assessor masked RCT). - Methods 698 first-time mothers with healthy term infants were allocated to receive anticipatory guidance on protective feeding practices or usual care. Outcomes were assessed at 2, 3.7 and 5 years (3.5 years post-intervention). Dietary intake was assessed by 24-hour recall and Child Dietary Questionnaire. Mothers completed a food preference questionnaire and Children’s Eating Behaviour Questionnaire. Linear mixed models assessed group, time and time x group effects. - Results There were no group or time x group effects for fruit, vegetables, discretionary food and non-milk sweetened beverages intake. Intervention children showed a higher preference for fruits (74.6% vs 69.0% liked, P<.001), higher Child Dietary Questionnaire score for fruit and vegetables (15.3 vs 14.5, target>18, P=0.03), lower food responsiveness (2.3 vs 2.4, of maximum 5, P=.04) and higher satiety responsiveness (3.1 vs 3.0, of maximum 5, P=.04). - Conclusions Compared to usual care, an early feeding intervention providing anticipatory guidance regarding positive feeding practices led to small improvements in child dietary score, food preferences and eating behaviours up to 5 years of age, but not in dietary intake measured by 24-hour recall.
Role of silicon in resisting subsurface plastic deformation in tribology of aluminium-silicon alloys
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Silicon particles standing proud on aluminium-silicon alloy surfaces provide protection in tribology. Permanent sinking of such particles into the matrix under load can be deleterious. The mechanical response of the alloy to nano-indentation of single silicon particles embedded in the matrix is explored. A nominal critical pressure required to plastically deform the matrix to permanently embed the particle is determined experimentally. Within a framework suggested by two-dimensional models of plastic response to indentation, a probable correlation is established between the normal mean pressure required to cause permanent sinking of silicon particles and a factor which relates the relevant particle dimensions.
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Homozygosity has long been associated with rare, often devastating, Mendelian disorders1, and Darwin was one of the first to recognize that inbreeding reduces evolutionary fitness2. However, the effect of the more distant parental relatedness that is common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power3, 4. Here we use runs of homozygosity to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts, and find statistically significant associations between summed runs of homozygosity and four complex traits: height, forced expiratory lung volume in one second, general cognitive ability and educational attainment (P < 1 × 10−300, 2.1 × 10−6, 2.5 × 10−10 and 1.8 × 10−10, respectively). In each case, increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months’ less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing evidence that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples5, 6, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection7, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been.
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Wear of etched near-eutectic aluminium silicon alloy slid against a steel ball under ambient is explored. The sliding velocity is kept low (0.01 m/s) and the nominal contact pressure is varied in a 15-40 MPa range. Four stages of wear are identified; ultra mild wear, mild wear, severe wear and post severe oxidative wear. The first transition is controlled by the protrusions of silicon particles, projecting out of the aluminium alloy matrix. Once these protrusions disappear under pressure and sliding, oxidation and bulk energy dissipation mechanisms take over to institute transitions to other stages of wear. The phenomenological characteristics of wear stages are explored using a variety of techniques including nanoindentation, focused ion beam milling, electron microscopy, X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and optical interferometry. (c) 2010 Elsevier B.V. All rights reserved.
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3,6-Bis (2 pyridyl) pyridazine has been synthesized and characterized by NMR, XRD and elemental analyses. The vibrational studies were carried out by using FTIR and Raman spectroscopy and the modes of vibrations were analysed and compared with the theoretically calculated values. The nonlinear optical property of the title compound was examined by Kurtz-Perry method and Hyper Raleigh scattering with the fundamental wavelength of 1064nm. This compound possesses less SHG efficiency but large first hyperpolarizability. (C) 2013 Elsevier GmbH. All rights reserved.
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ZnS quantum dots (QDs) of different sizes are synthesized by a simple chemical co-precipitation method at room temperature, by varying pH value of the reaction mixture. Samples are characterized by an X-ray diffractometer, transmission electron microscope, energy-dispersive X-ray analysis, etc. Linear optical properties, including UV-visible absorption and photoluminescence emission characteristics, of as-prepared QDs are measured. Size dependent nonlinear optical property, such as second harmonic generation (SHG) of 1064 nm Nd:YAG laser fundamental radiation in the synthesized ZnS QDs, is reported for the first time, to the best of our knowledge, by using the standard Kurtz-Perry powder method. In not to study the possibility of the synthesized ZnS QDs in different device applications ZnS/PMMA (polymethylmethacrylate) nanocomposites are also synthesized. The presence of weak chemical interaction between the polymer matrix and ZnS QDs is confirmed by Fourier transform infrared spectroscopy. Thermal properties of the nanocomposites are studied by differential scanning calorimetry and thermo-gravimetric analysis techniques, which show that the composites are stable up to similar to 300 degrees C temperature. (C) 2013 Elsevier B.V. All rights reserved.
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A novel thiophene derivative 7,9-di(thiophen-2-yl)-8H-cyclopentaa]acenaphthylen-8-one (DTCPA) is shown to exhibit high electrical conductivity (1.97 x 10(-2) +/- 0.0018 S/cm at RT) in the crystalline state. The material shows two orders of increase in conductivity from normal solid to single crystalline state. The crystal structure has S center dot center dot center dot S chalcogen bonding, C-H center dot center dot center dot O hydrogen bonding, and pi center dot center dot center dot pi stacking as the major intermolecular interactions. The nature and strength of the S center dot center dot center dot S interactions in this structure have been evaluated by theoretical charge density analysis, and its contribution to the crystal packing quantified by Hirshfeld surface analysis. Further, thermal and morphological characterizations have been carried out, and the second harmonic generation (SHG) efficiency has been measured using the Kurtz-Perry method.
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Global change is impacting forests worldwide, threatening biodiversity and ecosystem services including climate regulation. Understanding how forests respond is critical to forest conservation and climate protection. This review describes an international network of 59 long-term forest dynamics research sites (CTFS-ForestGEO) useful for characterizing forest responses to global change. Within very large plots (median size 25ha), all stems 1cm diameter are identified to species, mapped, and regularly recensused according to standardized protocols. CTFS-ForestGEO spans 25 degrees S-61 degrees N latitude, is generally representative of the range of bioclimatic, edaphic, and topographic conditions experienced by forests worldwide, and is the only forest monitoring network that applies a standardized protocol to each of the world's major forest biomes. Supplementary standardized measurements at subsets of the sites provide additional information on plants, animals, and ecosystem and environmental variables. CTFS-ForestGEO sites are experiencing multifaceted anthropogenic global change pressures including warming (average 0.61 degrees C), changes in precipitation (up to +/- 30% change), atmospheric deposition of nitrogen and sulfur compounds (up to 3.8g Nm(-2)yr(-1) and 3.1g Sm(-2)yr(-1)), and forest fragmentation in the surrounding landscape (up to 88% reduced tree cover within 5km). The broad suite of measurements made at CTFS-ForestGEO sites makes it possible to investigate the complex ways in which global change is impacting forest dynamics. Ongoing research across the CTFS-ForestGEO network is yielding insights into how and why the forests are changing, and continued monitoring will provide vital contributions to understanding worldwide forest diversity and dynamics in an era of global change.
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It is paramount that any child or adolescent with a suspected disorder of sex development (DSD) is assessed by an experienced clinician with adequate knowledge about the range of conditions associated with DSD. If there is any doubt, the case should be discussed with the regional team. In most cases, particularly in the case of the newborn, the paediatric endocrinologist within the regional DSD team acts as the first point of contact. The underlying pathophysiology of DSD and the strengths and weaknesses of the tests that can be performed should be discussed with the parents and affected young person and tests undertaken in a timely fashion. This clinician should be part of a multidisciplinary team experienced in management of DSD and should ensure that the affected person and parents are as fully informed as possible and have access to specialist psychological support. Finally, in the field of rare conditions, it is imperative that the clinician shares the experience with others through national and international clinical and research collaboration. © 2011 Blackwell Publishing Ltd.
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This is a report to the California Department of Parks and Recreation. It describes water quality and aquatic invertebrate monitoring after the construction of the Carmel River Lagoon Enhancement Project. Included are data that have been collected for two years and preliminary assessment of the enhanced ecosystem. This report marks the completion of 3-years of monitoring water quality and aquatic habitat. The report adopts the same format and certain background text from previous years’ reporting by the same research group (e.g. Larson et al., 2005). (Document contains 100 pages)
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Introduction [pdf, 0.17 MB] Warren S. Wooster [pdf, 0.12 MB] PICES - the first decade, and beyond Paul H. LeBlond [pdf, 0.03 MB] The Physical Oceanography and Climate Committee: The first decade D.E. Harrison and Neville Smith [pdf, 0.04 MB] Ocean observing systems and prediction - the next ten years Tsutomu Ikeda and Patricia A. Wheeler [pdf, 0.85 MB] Ocean impacts from the bottom of the food web to the top: Biological Oceanography Committee (BIO) retrospective Timothy R. Parsons [pdf, 0.2 MB] Future needs for biological oceanographic studies in the Pacific Ocean Douglas E. Hay, Richard J. Beamish, George W. Boehlert, Vladimir I. Radchenko, Qi-Sheng Tang, Tokio Wada, Daniel W. Ware and Chang-Ik Zhang [pdf, 0.2 MB] Ten years FIS in PICES: An introspective, retrospective, critical and constructive review of fishery science in PICES Richard F. Addison, John E. Stein and Alexander V. Tkalin [pdf, 0.12 MB] Marine Environmental Committee in review Robie W. Macdonald, Brian Morton, Richard F. Addison and Sophia C. Johannessen [pdf, 1.89 MB] Marine environmental contaminant issues in the North Pacific: What are the dangers and how do we identify them? R. Ian Perry, Anne B. Hollowed and Takashige Sugimoto [pdf, 0.36 MB] The PICES Climate Change and Carrying Capacity Program: Why, how, and what next? List of acronyms [pdf, 0.07 MB] (Document contains 108 pages)
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A workshop was convened by the MODEL Task Team and held June 23-28, 1996, in Nemuro, Japan, to develop the modeling requirements of the PICES Climate Change and Carrying Capacity (CCCC) Program. It was attended by over 40 scientists from all member nations of PICES. The principal objectives of the workshop were to • review the roles and limitations of modeling for the CCCC program; • propose the level of modeling required; and • provide a plan for how to promote these modeling activities. Secondary activities at the workshop included organisational meetings of the Regional comparisons (REX) and Basin-scale experiment (BASS) Task Teams, and a symposium by Japan-GLOBEC on “Development and application of new technologies for measurement and modeling in marine ecosystems.” This report serves as a record of the proceedings of this workshop. (PDF contains 89 pages)