992 resultados para PRE-BREEDING


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Materials used in the engineering always contain imperfections or defects which significantly affect their performances. Based on the large-scale molecular dynamics simulation and the Euler–Bernoulli beam theory, the influence from different pre-existing surface defects on the bending properties of Ag nanowires (NWs) is studied in this paper. It is found that the nonlinear-elastic deformation, as well as the flexural rigidity of the NW is insensitive to different surface defects for the studied defects in this paper. On the contrary, an evident decrease of the yield strength is observed due to the existence of defects. In-depth inspection of the deformation process reveals that, at the onset of plastic deformation, dislocation embryos initiate from the locations of surface defects, and the plastic deformation is dominated by the nucleation and propagation of partial dislocations under the considered temperature. Particularly, the generation of stair-rod partial dislocations and Lomer–Cottrell lock are normally observed for both perfect and defected NWs. The generation of these structures has thwarted attempts of the NW to an early yielding, which leads to the phenomenon that more defects does not necessarily mean a lower critical force.

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Crashes on motorway contribute to a significant proportion (40-50%) of non-recurrent motorway congestions. Hence reduce crashes will help address congestion issues (Meyer, 2008). Crash likelihood estimation studies commonly focus on traffic conditions in a Short time window around the time of crash while longer-term pre-crash traffic flow trends are neglected. In this paper we will show, through data mining techniques, that a relationship between pre-crash traffic flow patterns and crash occurrence on motorways exists, and that this knowledge has the potential to improve the accuracy of existing models and opens the path for new development approaches. The data for the analysis was extracted from records collected between 2007 and 2009 on the Shibuya and Shinjuku lines of the Tokyo Metropolitan Expressway in Japan. The dataset includes a total of 824 rear-end and sideswipe crashes that have been matched with traffic flow data of one hour prior to the crash using an incident detection algorithm. Traffic flow trends (traffic speed/occupancy time series) revealed that crashes could be clustered with regards of the dominant traffic flow pattern prior to the crash. Using the k-means clustering method allowed the crashes to be clustered based on their flow trends rather than their distance. Four major trends have been found in the clustering results. Based on these findings, crash likelihood estimation algorithms can be fine-tuned based on the monitored traffic flow conditions with a sliding window of 60 minutes to increase accuracy of the results and minimize false alarms.

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Crashes that occur on motorways contribute to a significant proportion (40-50%) of non-recurrent motorway congestions. Hence, reducing the frequency of crashes assists in addressing congestion issues (Meyer, 2008). Crash likelihood estimation studies commonly focus on traffic conditions in a short time window around the time of a crash while longer-term pre-crash traffic flow trends are neglected. In this paper we will show, through data mining techniques that a relationship between pre-crash traffic flow patterns and crash occurrence on motorways exists. We will compare them with normal traffic trends and show this knowledge has the potential to improve the accuracy of existing models and opens the path for new development approaches. The data for the analysis was extracted from records collected between 2007 and 2009 on the Shibuya and Shinjuku lines of the Tokyo Metropolitan Expressway in Japan. The dataset includes a total of 824 rear-end and sideswipe crashes that have been matched with crashes corresponding to traffic flow data using an incident detection algorithm. Traffic trends (traffic speed time series) revealed that crashes can be clustered with regards to the dominant traffic patterns prior to the crash. Using the K-Means clustering method with Euclidean distance function allowed the crashes to be clustered. Then, normal situation data was extracted based on the time distribution of crashes and were clustered to compare with the “high risk” clusters. Five major trends have been found in the clustering results for both high risk and normal conditions. The study discovered traffic regimes had differences in the speed trends. Based on these findings, crash likelihood estimation models can be fine-tuned based on the monitored traffic conditions with a sliding window of 30 minutes to increase accuracy of the results and minimize false alarms.

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Introduction Malnutrition is common among hospitalised patients, with poor follow-up of nutrition support post-discharge. Published studies on the efficacy of ambulatory nutrition support (ANS) for malnourished patients post-discharge are scarce. The aims of this study were to evaluate the rate of dietetics follow-up of malnourished patients post-discharge, before (2008) and after (2010) implementation of a new ANS service, and to evaluate nutritional outcomes post-implementation. Materials and Methods Consecutive samples of 261 (2008) and 163 (2010) adult inpatients referred to dietetics and assessed as malnourished using Subjective Global Assessment (SGA) were enrolled. All subjects received inpatient nutrition intervention and dietetic outpatient clinic follow-up appointments. For the 2010 cohort, ANS was initiated to provide telephone follow-up and home visits for patients who failed to attend the outpatient clinic. Subjective Global Assessment, body weight, quality of life (EQ-5D VAS) and handgrip strength were measured at baseline and five months post-discharge. Paired t-test was used to compare pre- and post-intervention results. Results In 2008, only 15% of patients returned for follow-up with a dietitian within four months post-discharge. After implementation of ANS in 2010, the follow-up rate was 100%. Mean weight improved from 44.0 ± 8.5kg to 46.3 ± 9.6kg, EQ-5D VAS from 61.2 ± 19.8 to 71.6 ± 17.4 and handgrip strength from 15.1 ± 7.1 kg force to 17.5 ± 8.5 kg force; p<0.001 for all. Seventy-four percent of patients improved in SGA score. Conclusion Ambulatory nutrition support resulted in significant improvements in follow-up rate, nutritional status and quality of life of malnourished patients post-discharge.

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Diagnostics of rolling element bearings involves a combination of different techniques of signal enhancing and analysis. The most common procedure presents a first step of order tracking and synchronous averaging, able to remove the undesired components, synchronous with the shaft harmonics, from the signal, and a final step of envelope analysis to obtain the squared envelope spectrum. This indicator has been studied thoroughly, and statistically based criteria have been obtained, in order to identify damaged bearings. The statistical thresholds are valid only if all the deterministic components in the signal have been removed. Unfortunately, in various industrial applications, characterized by heterogeneous vibration sources, the first step of synchronous averaging is not sufficient to eliminate completely the deterministic components and an additional step of pre-whitening is needed before the envelope analysis. Different techniques have been proposed in the past with this aim: The most widely spread are linear prediction filters and spectral kurtosis. Recently, a new technique for pre-whitening has been proposed, based on cepstral analysis: the so-called cepstrum pre-whitening. Owing to its low computational requirements and its simplicity, it seems a good candidate to perform the intermediate pre-whitening step in an automatic damage recognition algorithm. In this paper, the effectiveness of the new technique will be tested on the data measured on a full-scale industrial bearing test-rig, able to reproduce the harsh conditions of operation. A benchmark comparison with the traditional pre-whitening techniques will be made, as a final step for the verification of the potentiality of the cepstrum pre-whitening.

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Dermal wound healing is a biochemical and cellular process critical to life. While the majority of the population will only ever experience successful wound healing outcomes, some 1-3 % of those aged over 65 years will experience wound healing delay or perpetuation. These hard-to-heal wounds are comprised of degraded and dysfunctional extracellular matrix, yet the integrity of this structure is critical in the processes of normal wound healing. As such, extracellular matrix replacements have been devised that can replace dysfunctional extracellular matrix in hard-to-heal wounds with the aim of restoring normal wound healing processes. Here we evaluated a novel synthetic matrix protein for its ability to act as an acellular scaffold that can replace dysfunctional extracellular matrix. In this regard the synthetic protein demonstrated an ability to rapidly adsorb to the dermal surface, permit cell attachment and facilitate the cellular functions essential to wound healing. When applied to deep partial thickness wounds in a porcine animal model the matrix protein also demonstrated the ability to reduce wound duration. These data provide evidence that the synthetic matrix protein has the ability to function as an acellular scaffold for wound healing purposes.

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This paper explores the use of guided narrative reflection as a strategy used with high-achieving non-Indigenous pre-service teachers in Australia on teaching practicum. We suggest that reflections (and subsequent dialogue) can provide opportunities for non-Indigenous preservice teachers to re-think their beliefs and actions in ways that may intervene in the teaching that often causes educational disadvantage for Aboriginal and Torres Strait Islander students.

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A numerical procedure based on the plastic hinge concept for study of the structural behaviour of steel framed structures exposed to fire is described. Most previous research on fire analysis considered the structural performance due to rising temperature. When strain reversal occurs during the cooling phase, the stress–strain curve is different. The plastic deformation is incorporated into the stress–strain curve to model the strain reversal effect in which unloading under elastic behaviour is allowed. This unloading response is traced by the incremental–iterative Newton–Raphson method. The mechanical properties of the steel member in the present fire analysis follows both Eurocode 3 Part 1.2 and BS5950 Part 8, which implicitly allow for thermal creep deformation. This paper presents an efficient fire analysis procedure for predicting thermal and cooling effects on an isolated element and a multi-storey frame. Several numerical and experimental examples related to structural behaviour in cooling phase are studied and compared with results obtained by other researchers. The proposed method is effective in the fire safety design and analysis of a building in a real fire scenario. The scope of investigation is of great significance since a large number of rescuers would normally enter a fire site as soon as the fire is extinguished and during the cooling phase, so a structural collapse can be catastrophic.

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Case note Apache Energy Ltd v Alcoa of Australia Ltd (No 2) [2013] In 2011, headlines were made when Alcoa sued Apache Energy and its partners for $158 million, a loss it claimed was a consequence of Apache Energy failing to adequately inspect and maintain the gas pipelines that supplied the gas used by Alcoa in its business. As the loss was not a consequence of any property damage or injury to Alcoa, the loss is characterised as pure economic loss...

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The concept of the lifelong learner—the idea that people should be active learners throughout the lifespan—has since the 1990s gained importance in public policy. Governments in relatively wealthy countries have made the argument that the economic future of nations is tied to the ongoing participation of citizens in learning opportunities that will assist them to participate fully in society and increase their chances of employment in changing workforce conditions. More recently, policy attention has focused on the other end of the lifespan, the first years of life. With the early years now recognised as crucial for later educational success, policy attention has also focused on the importance of parenting in the early years. In the UK and Australia, for example, the effects of state interventions to facilitate ‘good parenting’ and pre-school children’s ‘readiness’ for formal schooling have been felt in a range of settings including community health services, the home and the pre-school (Gillies, 2005; Nichols & Jurvansuu, 2008; Millei & Lee, 2007; Vincent, Ball & Braun, 2010). In Australia, government policy has explicitly proposed a model of parenting as a learning process, and has urged people to cultivate their identities as learners in order to carry out their responsibilities as parents. In part the policy objectives have been to support parents to ensure that all children get a healthy and successful start to life...

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This paper discusses our experiences of integrating a Multi-User Virtual Environment (MUVE) called Quest Atlantis into a pre-service secondary science education unit. The use of educational MUVEs as teaching tools is accelerating, so it is crucial that pre-service teachers develop some expertise with these and related technologies. We outline the processes we followed in embedding Quest Atlantis into the content and assessment of the unit, the results of this initiative and its implications for integrating MUVEs and other ICTs into teacher education programs. Challenges such as limited time and expertise, demands of a busy teaching program, and the need for continuous specialist support need to be overcome for sustainable integration of MUVEs and related technologies into preservice teacher education. This is particularly important given the potential of preservice teachers as change agents in schools, and the imperatives of the ICT-related National Professional Standards for Teachers and the Australian Curriculum.

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While the role of university journalism education in the professionalization of journalists has been extensively debated, systematic and comparative studies of journalism students are still scarce. This paper reports the findings from a comparative study of journalism students in seven countries: Australia, Brazil, Chile, Mexico, Spain, Switzerland, and the United States. The data show a number of similarities, but also important differences between pre-professional cultures in journalism around the world. The findings are in line with recent conceptualizations of media systems, although some variations and particularities are observed at the country level. While students in all countries reject a loyal approach and favor a citizen-oriented role, they also do so to different extents. Brazilian and Chilean students believe in the citizen-oriented and watchdog roles, whereas their counterparts in Australia, Switzerland, and the United States favor the consumer-oriented approach to a greater extent. Mexican and Spanish students, on the other hand, while supporting the citizen-oriented role, reject the loyal role comparatively less than the rest of the countries.

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Since the 1970s, the Uppsala stages model has been one of the dominant explanations of firm internationalization. The model's focus on internationalization as a firm's gradual and incremental process of increasing international involvement has attracted much debate, with one criticism being that it is unclear in explaining how the internationalization process first originates within a firm. In this paper, the Uppsala model is extended through the incorporation of a pre-internationalization phase to explore the antecedents of firm internationalization. Adopting the Uppsala model's theoretical underpinnings, this paper develops and operationalizes a pre-internationalization phase decision heuristic in the form of an ‘export readiness index'. Four constructs are proposed that drive and inhibit export commencement decision-making during a firm's preinternationalization phase: export stimuli, attitudinal/psychological commitment, resources and lateral rigidity. Through a survey of Australian exporting and non-exporting small-medium sized enterprises (SMEs), the Export Readiness Index (ERI) is developed through factor analysis and tested using logistic regression. Results of the study and their potential implications are discussed.