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Lucerne (alfalfa, Medicago sativa L.) is grown extensively worldwide owing to its high forage biomass production and nutritional value. Although this crop is characterised as being tolerant to drought, its production and persistence are affected by water stress. Selection of genotypes of high yield potential and persistence after a long period of drought is a major objective for lucerne-breeding programmes in Mediterranean environments. This selection could be enhanced and accelerated by the use of physiological and productivity traits and their estimation through remote-sensing methods. A set of nine cultivars of lucerne from Australia and the USA were assessed in four locations in Mediterranean central-south Chile. Several physiological and productivity traits were evaluated: forage yield (FY), stomatal conductance (gs), water potential (WP), leaf area index (LAI), nitrogen (N) content, and isotope composition (δ13C and δ18O) of the dry matter. Spectral-reflectance data were used to estimate the traits through spectral-reflectance indices (SRIs) and multivariate regression methods. For the SRI-based estimations, the R² values for each assessment were <0.65. However, traits such as LAI, WP, gs, and N content showed higher R² values when data from the different assessments were combined. Regression-based estimation showed prediction power similar to or higher than the SRI-based approaches. The highest R² value was for δ13C (0.78), but for most traits the combination of data from different assessments led to higher trait estimation, with respective R² values for LAI, FY, WP and gs of 0.67, 0.71, 0.63 and 0.85. Among regression methods, the best estimation was achieved by using support vector machine regression. The use of spectral-reflectance data collected at field level and multivariate regression models has great potential to estimate physiological and productivity traits in lucerne under water deficit and could be useful in lucerne-breeding programmes. [ABSTRACT FROM AUTHOR]

Abstract: The potential benefits of using a legumes have not been evaluated in the rainfed, cropping systems of central Chile where wheat (Triticum aestivum) is typically grown in rotation with oats (Avena sativa) using high rates of nitrogen (N) fertilizer. Two experiments were initiated to compare unfertilized legume-wheat cropping sequences to the current oat–wheat system without and with applications of N fertilizer (160 or 207kgNha−1). One experiment was located in the interior dryland of central Chile (average annual rainfall 650mm), and the other in the Andean foothills (average annual rainfall 1200mm). Treatments were established in different areas of the same two experimental sites in consecutive years (2008 and 2009) resulting in four separate trials evaluating legume effects on wheat yield (2009 or 2010). Estimates of N2 fixation determined using the 15N natural abundance technique indicated that around 21kg shoot N was fixed for every tonne (t) of shoot dry matter accumulated by either narrow-leaf lupin (Lupinus angustifolius), field peas (Pisum sativum), yellow lupin (Lupinus luteus), or white lupin (Lupinus albus) grown for grain, and by vetch (Vicia atroporpurea) grown in association with oats for green manure. When the amounts of N2 fixed were adjusted to account for N in the nodulated roots, narrow-leaf lupin was calculated to have returned the lowest average net inputs of fixed N to the system following grain harvest (26kgNha−1) and field pea the highest (192kgNha−1). By comparison vetch in the green manure treatments where all above-ground biomass were incorporated into the soil returned 67kgfixedNha−1. Depending upon location and year, growing grain legumes increased the subsequent N uptake by wheat by up to 60kgNha−1 (average 35kgNha−1) and vetch+oats green manure up to 103kgNha−1 (average 50kgNha−1). Wheat yields after grain legumes ranged from 2.4 to 3.0tha−1 in the interior dryland and 5.4–6.4tha−1 in the Andean foothills which were respectively 72–110% (90% average) and 69–83% (75% average) of the yields achieved by N fertilized wheat. Wheat yields after the vetch+oats green manure were 1.8 and 7.9tha−1 representing 60% and 102% of the yield of N fertilized wheat. In the absence of N fertilizer or legumes wheat yields after oats were around half that of the N fertilized wheat. It was concluded that grain legumes or legume-based green manures provide opportunities to greatly reduce the reliance of wheat production upon N fertilizer. [Copyright &y& Elsevier]

• Identification of people living under 14 °C susceptible to cold-related ill-health. • 90% of people invest more than 10% of the minimum wage on energy. • Discomfort time is correlated with the number of respiratory illnesses reported by the participants in the surveys. • The most vulnerable group are people who spend more than 35% of their time in discomfort. Energy poverty (EP) occurs when there are no energy services available or not at an affordable price, or when homes are not capable of maintaining minimum thermal comfort conditions. It is associated with a series of adverse consequences for the people's health and with a higher number of deaths in winter in most European countries. The objective of this research was to study whether the thermal comfort levels, the state of the dwellings, the heating systems, the energy expenses, the respiratory illnesses and the medical expenses reported by social housing inhabitants in central-south Chile, were correlated, to determine which variables or combination of variables are more related with EP situations. To define the thermal comfort limits, a recently published adaptive thermal comfort model for low income housing in Chile was used. The results show that a third of those surveyed were not capable of keeping their home comfortable for at least 80% of the time and more than a fifth were incapable of doing so 65% of the time. Only 10% of those who were capable of keeping comfort levels more than 90% of the time, spend less than US$ 40 a month, which represents 10% of the minimum Chilean wage. Reducing the time that temperatures are below the lower comfort limit to 10% can mean a reduction in the number of respiratory illnesses and medical expenses. [ABSTRACT FROM AUTHOR]

Worldwide, there is an alert due to the increase in the seroprevalence of hepatitis B virus (HBV). This can cause up to 3.5% of chronic diseases, of which 40% present secondary complications and/ or early death., Objective: To determine the seroprevalence of HBV in pregnant women at the time of delivery., Patients and Method: Observational, descriptive, cross-sectional study with cross-association between 2018 and 2019 at the Hospital Carlos Van Buren (HCVB), in Valparaiso, Chile. All pregnant women admitted for delivery care or with an immediate newborn who had HBV surface antigen study were included. Data were collected from the pregnant woman (age, nationality, education level, parity, type of delivery, and peripartum HIV-syphilis serology) and the newborn (gestational age, weight, and APGAR score). Inferential and multivariate analysis was performed using the Stata software., Results: 1,355 pregnant women were analyzed. 87.7% were Chilean, 5.5% Haitian, 4.2% Venezuelan, and 2.6% were of other nationalities. 0.3% were positive for HBV. The prevalence of HBV in Chileans was 0.08% and in Haitians 4%. Haitian nationality was at higher risk of HBV (OR = 83) vs. Chilean nationality (p = 0.0001). None presented coinfection with HIV and/or syphilis., Conclusions: HBV seroprevalence in HCVB pregnant women was 0.3%, similar to that described in the general population in Chile. There was no coinfection with other sexually transmitted diseases. The only predictor of HBV infection was Haitian nationality.

Background: Given the relevance of social support on the mental health of older adults, having an instrument to evaluate this variable is essential for research in the area. However, mainly, having instruments with suitable evidence of their psychometric properties is critical. For this reason, this study sought to evaluate the factorial and reliability structure of the Multidimensional Scale of Perceived Social Support within autonomous older adults from the Province of Concepción, Chile., Methods: We surveyed 399 older adults using quote sampling. They answered a Spanish version of the Multidimensional Scale of Perceived Social Support, plus a sociodemographic questionnaire. We performed confirmatory factor analysis using Weighted Least Squares Means and Variances adjusted estimation (WLSMV) to compare the factor models proposes by previous studies. To evaluate reliability, we calculated Cronbach's alpha and McDonald's omega., Results: The Confirmatory factor analysis found that the 3-factors models showed the best fist index between the models with CFI = 0.991, TLI = 0.989, and SRMR = 0.035, even though RMSEA were over the cutoff point. The factors presented reliabilities from α = 0.858 to α = 0.941, and from ω = 0.937 to ω = 0.972., Conclusions: The results support the existence of three factors for the Multidimensional Scale of Perceived Social Support (MSPSS), differentiating the support perceived from Family, Friends, and significant others. All factors present good or excellent reliability. This solution is theoretically consistent and coherent with the literature, and it presents evidence in favor of the use of MSPSS as a measurement to distinguish the support perceived source., (© 2021. The Author(s).)

In the Porcelana Hot Spring (Northern Patagonia), true-branching cyanobacteria are the dominant primary producers in microbial mats, and they are mainly responsible for carbon and nitrogen fixation. However, little is known about their metabolic and genomic adaptations at high temperatures. Therefore, in this study, a total of 81 Fischerella thermalis strains (also known as Mastigocladus laminosus) were isolated from mat samples in a thermal gradient between 61-46°C. The complementary use of proteomic comparisons from these strains, and comparative genomics of F. thermalis pangenomes, suggested that at least two different ecotypes were present within these populations. MALDI-TOF MS analysis separated the strains into three clusters; two with strains obtained from mats within the upper temperature range (61 and 54°C), and a third obtained from mats within the lower temperature range (51 and 46°C). Both groups possessed different but synonymous nifH alleles. The main proteomic differences were associated with the abundance of photosynthesis-related proteins. Three F. thermalis metagenome assembled genomes (MAGs) were described from 66, 58 and 48°C metagenomes. These pangenomes indicated a divergence of orthologous genes and a high abundance of exclusive genes at 66°C. These results improved the current understanding of thermal adaptation of F. thermalis and the evolution of these thermophilic cyanobacterial species., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Background: Hydatid disease or cystic echinococcosis, caused by the parasite Echinococcus granulosus, has a worldwide distribution, affecting people of working age and can cause high levels of morbidity and even death., Aim: To estimate the economic impact at the human and animal level caused by the disease in Chile., Material and Methods: We analyzed information about the disease obtained from reports and publications emanated from the Chilean Ministry of Health, United Nations Food and Agriculture Organization, the U.S. National Institute of Statistics and the National Agricultural Service. Animal derived costs were estimated evaluating the expenses for pharmacological treatment of infected dogs and animal production losses derived from confiscations and reductions in meat production., Results: The total number of patients who underwent surgery to remove a hydatid cyst in Chile during 2012, was estimated as 767 individuals. The annual costs derived only from surgical treatment, were estimated in USD 2.46 million. Summing the costs of sick leaves and loss of productivity, the costs at the human level ascended to USD 3.13 million. Considering human and animal costs, the annual economic burden of the disease was estimated in USD 14.35 million., Conclusions: The Analysis of the regional distribution of human and animal hydatidosis, suggests a significant environmental contamination with parasite eggs in high incidence regions such as Aysén, Araucanía, BioBío and Coquimbo. The efficiency of control programs for the disease would be greatly improved if the causes for these regional contaminations are elucidated.

This study was carried out from April to December 1990 in the commune of Valdivia, Chile and involved 207 physicians, nurses, midwives, and nurse-midwives. The objective was to determine the relationship between subjective attitude and personal behavior on the part of these health professionals with regard to the practice of monthly breast self-examination (BSE). The data were collected by means of an instrument designed to measure attitudes, which was prepared by Victoria Lee Champion (1984) on the basis of the health beliefs model of Becker, et al. (1974). Also included were questions aimed at ascertaining the personal and sociodemographic background of the professionals surveyed and their knowledge of several aspects of breast cancer and BSE. The information collected was subjected to the following tests of validity and reliability: Person product-moment correlation coefficient r, split half method, Spearman-Brown R coefficient, Cronbach alpha coefficient, and the Chi-square test to determine the degree of association between the variables. The results showed that although 79% of the women studied had ample knowledge of many aspects of breast cancer and 82% were aware of the benefits of BSE, only 28% practiced it on a monthly basis. It is alarming that health professionals, who are responsible for teaching prevention measures to other people, have yet to assume responsibility for protecting their own health insofar as early detection of breast cancer is concerned.