Effect of Process Parameters on Laser Powder Bed Fusion of Al-Sn Miscibility Gap Alloy

Al-Sn binary system is a miscibility gap alloy consisting of an Al-rich phase and a Sn-rich phase. This system is traditionally applied in bearings and more recently found application as form-stable phase change material (PCM) exploiting solid-liquid phase transition of Sn. A careful choice of production process is required to avoid macro-segregation of the two phases, which have different densities and melting temperatures. In the present study, the additive manufacturing process known as laser powder bed fusion (LPBF) was applied to an Al-Sn alloy with 20% volume of Sn, as a rapid solidification process. The effect of process parameters on microstructure and hardness was evaluated. Moreover, feasibility and stability with thermal cycles of a lattice structure of the same alloy were experimentally investigated. An Al-Sn lattice structure could be used as container for a lower melting organic PCM (e.g., a paraffin or a fatty acid), providing high thermal diffusivity thanks to the metallic network and a "safety system" reducing thermal diffusivity if the system temperature overcomes Sn melting temperature. Even if focused on Al-Sn to be applied in thermal management systems, the study offers a contribution in view of the optimization of manufacturing processes locally involving high solidification rates and reheat cycles in other miscibility gap alloys (e.g., Fe-Cu) with similar thermal or structural applications

Tailoring parameter distributions to specific germplasm : impact on crop model-based ideotyping

Crop models are increasingly used to identify promising ideotypes for given environmental and management conditions. However, uncertainty must be properly managed to maximize the in vivo realizability of ideotypes. We focused on the impact of adopting germplasm-specific distributions while exploring potential combinations of traits. A field experiment was conducted on 43 Italian rice varieties representative of the Italian rice germplasm, where the following traits were measured: light extinction coefficient, radiation use efficiency, specific leaf area at emergence and tillering. Data were used to derive germplasm-specific distributions, which were used to re-run a previous modelling experiment aimed at identifying optimal combinations of plant trait values. The analysis, performed using the rice model WARM and sensitivity analysis techniques, was conducted under current conditions and climate change scenarios. Results revealed that the adoption of germplasm-specific distributions may markedly affect ideotyping, especially for the identification of most promising traits. A re-ranking of some of the most relevant parameters was observed (radiation use efficiency shifted from 4th to 1st), without clear relationships between changes in rankings and differences in distributions for single traits. Ideotype profiles (i.e., values of the ideotype traits) were instead more consistent, although differences in trait values were found

Exploration of virtual body-representation in adolescence : the role of age and sex in avatar customization

The malleable nature of the self led researchers to investigate the meaning of virtual identity by exploring virtual self-representation through avatars and its association with users\u2019 identity. The present study aims to investigate the changes in virtual body-representation in adolescence related to age levels and sex and the association with adolescents\u2019 self-esteem and body esteem. Anthropometric features, body esteem and self-esteem were used to assess adolescents\u2019 body image and identity. The scoring code of the \u201cDrawing Me\u201d graphical test was used to evaluate the avatars. The sample is composed of 63 adolescents of different ages\u2014early, middle and late adolescence\u2014balanced by sex. Results show that the creation of a digital avatar changes with age and is partially associated with adolescents\u2019 perceptions in terms of body esteem and self-esteem. Moreover, the creation of avatars occurs differently for boys, who enrich their avatars with many sexual features, than for girls, who prefer to detail their avatars\u2019 clothing to enrich them. Critical reflections and implications for psychological interventions that may use avatars to investigate adolescents\u2019 identity in integration with other tools will be discussed

Histamine food poisonings: A systematic review and meta-analysis

ABSTRACTObjective: The aim of this study was to assess the mean of histamine concentration in food poisoning.Design: Systematic review and meta-analysis of reports published between 1959 and 2013.Study selection: Main criteria for inclusion of studies were: all report types that present outbreaks of "histamine poisoning' or "scombroid syndrome" from food, including histamine content and type of food. Health status of people involved must be nonpathological.Results: Fifty-five (55) reports were included, these studies reported 103 incidents. All pooled analyses were based on random effect model; histamine mean concentration in poisoning samples was 1107.21 mg/kg with confidence interval for the meta-mean of 422.62–2900.78 mg/kg; heterogeneity index (I2) was 100% (P < 0.0001); prediction interval was 24.12–50822.78 mg/kg. Fish involved in histamine poisoning was mainly tuna or Istiophoridae species. No clues of association between concomitant conditions (female sex, alcohol consumption, previous medication,..

Saúde na Amazônia: um modelo conceitual para a análise de paisagens e doenças

A REVIEW is made of the epidemiological profile of the human population in the Brazilian Amazon region, as related to the social and environmental dynamics of the region. A conceptual model for analysis is proposed including three major categories of landscapes: Natural, Anthropic and Built. Each of these macro landscapes is associated to a well defined set of health outcomes. Using an original concept of Disease Landscape, adapted from the classical Landscape Epidemiology, a comparative analysis of the epidemiological dynamics is made in six malaria landscapes, defined on the basis of land use strategies.NESTE TRABALHO faz-se uma revisão do perfil epidemiológico das populações amazônicas em relação com a dinâmica socioambiental da região. Propõe-se um modelo conceitual de análise que inclui três grandes categorias de paisagens na Amazônia: naturais, antropizadas e construídas. A cada uma destas macropaisagens identifica-se um conjunto bem definido de agravos à saúde. Utilizando-se um conceito próprio de paisagem de doença, modificado da epidemiologia paisagística clássica, é feita uma análise comparativa da dinâmica epidemiológica da malária em seis tipos de paisagens, definidas com base em formas de usos da terra

Prediction of the chemical composition and nutritive value of lucerne (Medicago sativa L.) by Near Infrared Spectroscopy

Lucerne is a low input energy efficient crop that improves soil fertility, and its importance is rising with the increase of public interest in sustainable agriculture. Furthermore, it occupies a significant economic position in the animal feed market (i.e. hay, dehydrated forage, pellets and silage products) and deserves a particular interest in the Parmigiano-Reggiano and Grana Padano cheese production areas of Northern Italy (Torricelli et al., 2000)

Analysis and modeling of processes involved with salt tolerance and rice

Salinity is a worldwide problem for rice (Oryza sativa L.) cultivation, and a number of breeding programs targeting increased salt tolerance are ongoing. A new trait-based mathematical model for salt stress on rice was recently proposed, characterized by a high level of detail in the description of physiological mechanisms dealing with crop response to salinity. In this study, dedicated growth chamber experiments were performed where three rice cultivars with different degrees of tolerance were grown under different salinity levels. The aim was to improve the understanding of physiological mechanisms like Na+ uptake and sequestration in structural tissues, and to validate the model using new datasets where temporal dynamics in plant response to salt stress were analyzed. Model evaluation demonstrated strong agreement between measured and simulated dry weights of plant organs (e.g., R2 = 0.88-0.97 for aboveground biomass), [Na+] in plant tissues (R2 = 0.73-0.88), and green leaf area index (R2 = 0.71-0.99). These results demonstrate the reliability of the model and support its adoption within studies aimed at analyzing or predicting the response of different cultivars to temporal dynamics of Na+ concentration in soil and water

Trait-based model development to support breeding programs : A case study for salt tolerance and rice

Eco-physiological models are increasingly used to analyze G 7 E 7 M interactions to support breeding programs via the design of ideotypes for specific contexts. However, available crop models are only partly suitable for this purpose, since they often lack clear relationships between parameters and traits breeders are working on. Taking salt stress tolerance and rice as a case study, we propose a paradigm shift towards the building of ideotyping-specific models explicitly around traits involved in breeding programs. Salt tolerance is a complex trait relying on different physiological processes that can be alternatively selected to improve the overall crop tolerance. We developed a new model explicitly accounting for these traits and we evaluated its performance using data from growth chamber experiments (e.g., R2 ranged from 0.74 to 0.94 for the biomass of different plant organs). Using the model, we were able to show how an increase in the overall tolerance can derive from completely different physiological mechanisms according to soil/water salinity dynamics. The study demonstrated that a trait-based approach can increase the usefulness of mathematical models for supporting breeding programs

Inhaled corticosteroids reduce neutrophilic bronchial inflammation in patients with chronic obstructive pulmonary disease.

Abstract BACKGROUND: Airways inflammation is a feature of chronic obstructive pulmonary disease (COPD), but the role of corticosteroids in the management of clinically stable patients has yet to be established. A randomised controlled study was carried out to investigate the effect of high dose inhaled beclomethasone dipropionate (BDP) administered for two months to patients with stable, smoking related COPD. Sputum induction was used to evaluate bronchial inflammation response. METHODS: 34 patients (20 men and 14 women) were examined on three separate occasions. At the initial clinical assessment (visit 0), spirometry and blood gas analysis were performed. On visit 1 (within one week of visit 0) sputum induction was performed and each patient was randomised to receive either BDP 500 micrograms three times daily (treated group) or nothing (control group). After two months (visit 2), all patients underwent repeat clinical assessment, spirometry, and sputum induction. RESULTS: There were no differences in sputum cell counts between the groups at baseline. After two months of treatment, induced sputum samples from patients in the treated group showed a reduction in both neutrophils (-27%) and total cells (-42%) with respect to baseline, while the control group did not (neutrophils +9%, total cells +7%). Macrophages increased in the treated group but not in the control group. The mean final value of sputum neutrophils was 52% in the treated group and 73.3% in the control group (95% confidence interval (CI) -27.2 to -15.4). The mean final value of sputum macrophages was 35.8% in treated group and 19.3% in control group (95% CI 10.3 to 22.8). The differences between the treated and control groups for neutrophils (-21.3%), macrophages (+16.5%), and total cells (-65%) were significant. Spirometry and blood gas data did not change from baseline in either patient group. CONCLUSIONS: A two month course of treatment with high dose inhaled BDP reduces significantly neutrophil cell counts in patients with clinically stable, smoking related COPD. Further studies on the effectiveness of inhaled steroids in COPD are needed to confirm the clinical importance of this observation

Histamine food poisoning : a systematic review and meta anlysis

Objective: Aim of this study was to assess the mean of histamine concentration in food poisoning. Design: Systematic review and meta-analysis of reports published between 1959-2013. Study selection: main criteria for inclusion of studies were: all report types that present outbreaks of \u201chistamine poisoning\u201d or \u201cscombroid syndrome\u201d from food, including histamine content and type of food. Health status of people involved must be non pathological. Results: Fifty-five (55) reports were included, these studies reported 103 incidents. All pooled analyses were based on random effect model; histamine mean concentration in poisoning samples was 1107.21 mg/kg with a prediction 95% interval of 422.62 - 2900.78 mg/kg; heterogeneity index (I2) was 100 % (P<0.0001); prediction interval was 24.12 \u2013 50822.78 mg/kg. Fish involved in histamine poisoning was mainly tuna or Istiophoridae species. No clues of association between concomitant conditions (female sex, alcohol consumption, previous medication and consumption of histamine releasing food) and histamine poisoning, were highlighted. Conclusions: This is the first systematic review and meta-analysis that analyzes all the available data on histamine poisoning outbreaks evaluating the histamine concentration in food involved. Histamine mean concentration in poisoning samples was fairly high. Our study suffers from some limitations, which are intrinsic of the studies included, for instance the lack of a complete anamnesis of each poisoning episode