Ammonia emissions from livestock production in Chile: an inventory and uncertainty analysis

Indexación: Web of Science; Scielo.The objective of this work was to quantify the country's NH3 emissions from livestock production. This calculation was based on the mass flow of total ammoniacal nitrogen (TAN). The analysis was performed for all 15 geographical regions in Chile. The definition of livestock subcategories was based on data from the Chilean Agriculture and Forestry Census as well as technical reports published by the Chilean National Statistics Institute. Significant differences were observed among the sources of livestock emissions in Chile's regions, and there was high variability depending on the degree of livestock confinement. In 2013, the total calculated emissions were 69.1 kt NH3/year (± 31.1). The O’Higgins Region had the highest NH3 emissions in Chile, representing 45% of the total. In terms of livestock production, 45% of the emissions were generated by pigs, 22% by poultry, 16% by cattle, 11% by equines and 4% by sheep. Emissions from the TAN that was available during manure and slurry management and the degree of animal confinement were the primary sources of uncertainty. This uncertainty could be greatly reduced by developing regional emission factors and by including the degree of animal confinement in Chile's national statistics such as the Agriculture, Livestock and Forestry Census.http://www.scielo.cl/scielo.php?pid=S0718-95162016005000005&script=sci_abstrac

First proof of concept of remote attendance for future observation strategies between Wettzell (Germany) and Concepción (Chile)

Current VLBI observations are controlled and attended locally at the radio telescopes on the basis of pre-scheduled session files. Operations have to deal with system specific station commands and individual setup procedures. Neither the scheduler nor the correlator nor the data-analyst gets real-time feedback about system parameters during a session. Changes in schedules after the start of a session by remote are impossible or at least quite difficult. For future scientific approaches, a more flexible mechanism would optimize the usage of resources at the sites. Therefore shared-observation control between world-wide telescope s, remote attendance/control as well as completely unattended-observations could be useful, in addition to the classic way to run VLBI observations. To reach these goals, the Geodetic Observatory Wettzell in cooperation with the Max-Planck-Institute for Radio Astronomy (Bonn) have developed a software extension to the existing NASA Field System for remote control. It uses the principle of a remotely accessible, autonomous process cell as server extension to the Field System on the basis of Remote Procedure Calls (RPC). Based on this technology the first completely remote attended and controlled geodetic VLBI session between Wettzell, Germany and Concepción, Chile was successfully performed over 24 hours. This first test was extremely valuable for gathering information about the differences between VLBI systems and measuring the performance of internet connections and automatic connection re-establishments. During the 24h-session, the network load, the number of sent/received packages and the transfer speed were monitor ed and captured. It was a first reliable test for the future wishes to control several telescopes with one graphical user interface on different data transfer rates over large distances in an efficient way. In addition, future developments for an authentication and user role management will be realized within the upcoming NEXPReS project

Root morphology of mandibular molars: a cone-beam computed tomography study

Background: The aim of the study was to assess the number and anatomical classification of roots and root canals of first and second mandibular molars using cone-beam computed tomography (CBCT) in a Chilean population. Materials and methods: This study evaluated the CBCT scans of 289 patients aged between 14 and 86 years, obtaining a sample of 1022 mandibular first and second molars. The number of roots and root canals was evaluated according to the anatomical classification proposed by Ahmed in 2016. Data were analysed using Pearson’s chi-squared test and ANOVA. Results: Nine hundred fifty-one (93.05%) molars had two roots, while the remaining 71 (6.95%) molars had one root. The most frequent root and root canal morphologies found were: 2MM M2 D1 (29.65%),  2MM M2-1 D1 (22.3%) and 2MM M1 D1 (13.4%) (M — mesial, D — distal), with a total of 32 different anatomical distributions. C-shaped canals were present in 56 molars and were more frequently found in women than in men (7.1% vs. 3.88%; p = 0.024). Conclusions: The analysis of internal anatomy using CBCT revealed a highly variable distribution of root canals. The most frequent morphology found in mandibular molars in a Chilean population was two roots and three canals

The effect of solar energy on the environmental profile of electricity generation in Chile: a midterm scenario

The Atacama Desert in Northern Chile features the highest solar radiation on continental soil worldwide, ranging within 2,500–3,400 kWh/m2/year, with UV-B radiation levels 65% above average European. This desert covers an extension over 105,000 km2 receiving more than 4,000 hours of sunshine yearly, and hosts large reserves of copper, lithium, molybdenum and other metallic and non-metallic minerals. Thus, the Chilean mining industry accounts for more than 30% of the total electricity consumption in the country. During the last 3 years major investments on solar photovoltaic (PV) plants have taken place at the Atacama Desert, driven by the drastic drop in the cost of PV technology, and incentives provided by the new Energy 2050 Roadmap set by the Chilean government, with view to fostering the introduction of renewable energy sources in the electricity market. The Chilean electricity system is composed of two connected grids, namely the Greater Northern Network (SING) and the Central Network (SIC), with a total installed capacity of nearly 21 GW. The SING network is mostly composed of thermoelectric power plants, whereas the SIC network features a significant share of hydroelectric plants, leading to different carbon footprint, namely 0.9 and 0.3 ton CO2eq/MWh, at SING and SIC, respectively. At the end of 2017, those grids were connected to meet the current 80 TWh/year national demand. Massive introduction of PV electricity generation plants at the Atacama Desert is foreseen in the near future, to reach a projected share around 25% by 2050. Within this framework, this paper presents novel results on the effect of solar energy on the environmental profile of electricity in Chile in a midterm scenario, using a life cycle assessment approach, under conditions of drastic reductions in water availability due to climate change. Results show that PV systems make a significant contribution to environmental impacts associated to electricity generation in the national mix by 2050, mainly in ozone layer depletion, abiotic depletion, global warming, acidification, and photochemical oxidation potentials impact categories, mainly from upstream transport and cell manufacturing. The extent of those impacts could increase significantly if the PV lifespan decreases due to cells degradation as a result of harsh environmental conditions, highlighting the need for reliable data on this key parameter

Implicancias ambientales de la deslignificación de pulpas kraft de eucalipto utilizando perácidos

Because of great environmental pressures, the cellulose industry has studied the potential of use of new bleaching agents among which peroxymonosulfuric acid and peracetic acid stand out. This survey summarizes the results of various laboratory investigations using peracids to delignify eucalyptus kraft pulps. The effect of a step using peroxymonosulfuric acid followed by a D-Eo-D sequence [free of elemental chlorine] was studied and compared with the use of peracetic acid and mixtures of these two acids. It was shown that a mixture of peroxymonosulfuric acid and peracetic acid reduced more lignin (measured as kappa index) than the individual peracids, and reduced more hexenuronic acid than peracetic acid with less degradation of the cellulose than with peroxymonosulfuric acid. This was explained on the basis of the electrophilic and nucleophilic properties of these acids that improved the delignification of eucalyptus kraft pulp. The effluents generated in these steps involving the peracids had greater color, chemical oxygen demand (COD), and total phenols correlating with the amount of lignin removed and the analyses of bioassays did not show acute toxicity from effluents coming from a peroxymonosulfuric acid step. The delignification with peracids may possibly reduce the use of chlorine dioxide in a sequence involving bleaching with elemental free chlorine (ECF), in this way reducing the concentration of organic chlorides (AOX) in the bleaching effluent

Tratamento de infecção corneana causado pelo Fonsecaea pedrosoi: relato de caso

To report an unusual case of fungus keratitis due to Fonsecaea pedrosoi that developed after corneal trauma. Case report: A 18-year-old male presented with a corneal ulcer in the right eye, 28 days after a trauma with glass fragments. Corneal scrapings were collected for smears and culture. Dematiaceous hyphae were seen on wet mounts of the scrapings and dark pigmented colonies grew repetitively on the culture media; all colonies were identical, and were subsequently identified as Fonsecaea pedrosoi. Treatment was initiated with topical natamycin at one hour intervals, 200 mg oral ketoconazole per day and later changed to a combination of 200 mg ketoconazole and amphotericin B. In humid tropical regions Fonsecaea pedrosoi is one of the primary causes of human chronic cutaneous mycosis, chromoblastomycosis. Combination of systemic and topical antifungal medications may provide the best option for cure in corneal chromoblastomycosis.Relato de um caso atípico de infecção fúngica da córnea causada pelo microrganismo Fonsecaea pedrosoi após trauma ocular. Paciente, masculino, estudante de 18 anos, apresentou-se ao Setor de Doenças Externas Oculares do Departamento de Oftalmologia da UNIFESP com úlcera de córnea paracentral de 3,5 x 3,5 mm e aspecto branco-acinzentado com bordas infiltradas, 28 dias após trauma em ocular por vidro. Foi realizado raspado da córnea e o material enviado para análise microbiológica. Foi observado crescimento de colônias em meio de cultura e posteriormente colocadas em solução de lactofenol-azul de algodão. Verificou-se a presença de hifas dermáceas de pigmento escuro, identificado como Fonsecaea pedrosoi. Tratamento foi iniciado com natamicina 5% tópica a cada hora e cetoconazol 200 mg por dia. Subseqüentemente foi substituído pela combinação cetoconazol e anfotericina B. Fonsecaea pedrosoi é uma das principais causas em humanos de micose crônica cutânea, cromoblastomicose, em regiões úmidas tropicais. A combinação de antimicóticos sistêmicos e tópicos pode ser a melhor opção para pacientes no tratamento de cromoblastomicose da córnea.Universidade Federal de São Paulo (UNIFESP) Departamento de OftalmologiaUniversitat Rovira I Virgili Facultat de Medicina I Ciencies de la SalutUNIFESP Departamento de OftalmologiaUNIFESP Departamento de Microbiologia e ParasitologiaUniversity Austral de Chile Microbiology Unitat ClinicUNIFESP, Depto. de OftalmologiaUNIFESP, Depto. de OftalmologiaUNIFESP, Depto. de Microbiologia e ParasitologiaSciEL