6,433 research outputs found
Life cycle assessment of drinking water: comparing conventional water treatment, reverse osmosis and mineral water in glass and plastic bottles
This study evaluated the environmental impacts caused by drinking water consumption in Barcelona (Spain) using the Life Cycle Assessment (LCA) methodology. Five different scenarios were compared: 1) tap water from conventional drinking water treatment; 2) tap water from conventional drinking water treatment with reverse osmosis at the water treatment plant; 3) tap water from conventional drinking water treatment with domestic reverse osmosis; 4) mineral water in plastic bottles, and 5) mineral water in glass bottles. The functional unit was 1 m3 of water. The water treatment plant considered in scenarios 1, 2 and 3, treats around 5 m3 s-1 of surface water. The water bottling plants considered in scenarios 4 and 5 have a production capacity of 200 m3 of bottled water per day. The LCA was performed with the software SimaPro®, using the CML 2 baseline method. The results showed how tap water consumption was the most favourable alternative, while bottled water presented the worst results due to the higher raw materials and energy inputs required for bottles manufacturing, especially in the case of glass bottles. The impacts generated by domestic reverse osmosis were between 10 and 24% higher than tap water alternative depending on the impact category. It was due to the higher electricity consumption. Reverse osmosis at the water treatment plant showed impacts nearly twice as high as domestic reverse osmosis systems scenario, mainly because of the higher energy inputs. Water treated by domestic reverse osmosis equipment was the most environmentally friendly solution for the improvement of tap water organoleptic characteristics. An economic analysis showed that this solution was between 8 and 19 times cheaper than bottled water.Peer ReviewedPostprint (author's final draft
Use of Eye Tracking as an Innovative Instructional Method in Surgical Human Anatomy
Tobii glasses can record corneal infrared light
reflection to track pupil position and to map gaze focusing
in the video recording. Eye tracking has been proposed for
use in training and coaching as a visually guided control
interface. The aim of our study was to test the potential use
of these glasses in various situations: explanations of
anatomical structures on tablet-type electronic devices,
explanations of anatomical models and dissected cadavers,
and during the prosection thereof. An additional aim of the
study was to test the use of the glasses during laparoscopies
performed on Thiel-embalmed cadavers (that allows pneu-
moinsufflation and exact reproduction of the laparoscopic
surgical technique). The device was also tried out in actual
surgery (both laparoscopy and open surgery)
Magnetic Field Effect in the Fine-Structure Constant and Electron Dynamical Mass
We investigate the effect of an applied constant and uniform magnetic field
in the fine-structure constant of massive and massless QED. In massive QED, it
is shown that a strong magnetic field removes the so called Landau pole and
that the fine-structure constant becomes anisotropic having different values
along and transverse to the field direction. Contrary to other results in the
literature, we find that the anisotropic fine-structure constant always
decreases with the field. We also study the effect of the running of the
coupling constant with the magnetic field on the electron mass. We find that in
both cases of massive and massless QED, the electron dynamical mass always
decreases with the magnetic field, what can be interpreted as an inverse
magnetic catalysis effect.Comment: To appear in Phys. Rev.
The hematopoietic stem-cell niche in health and leukemia
Research in the last decade has shown that hematopoietic stem cells (HSCs) interact with and are modulated by a complex multicellular microenvironment in the bone marrow, which includes both the HSC progeny and multiple non-hematopoietic cell types. Intense work is gradually throwing light on the composition of the HSC niche and the molecular cues exchanged between its components, which has implications for HSC production, maintenance and expansion. In addition, it has become apparent that bidirectional interactions between leukemic cells and their niche play a previously unrecognized role in the initiation and development of hematological malignancies. Consequently, targeting of the malignant niche holds considerable promise for more specific antileukemic therapies. Here we summarize the latest insights into HSC niche biology and recent work showing multiple connections between hematological malignancy and alterations in the bone marrow microenvironment.We thank members of the SM-F group for helpful discussions. This work was supported by core support grants from the Wellcome Trust and MRC to the Cambridge Stem Cell Institute, the Spanish Ministry of Economy and Competitiveness (SAF-2011-30308), Pro-CNIC Foundation, Severo Ochoa Center of Excellence award SEV-2015-0505 to CNIC, TerCel (Spanish Cell Therapy Network), Ramon y Cajal Program grants RYC-2011-09726 to AS-A and RYC-2009-04703 to SM-F), Marie Curie Career Integration Program grants (FP7-PEOPLE-2011-RG-294262/294096) to AS-A and SM-F; and a ConSEPOC-Comunidad de Madrid grant (S2010/BMD-2542) and Horizon2020 (ERC-2014-CoG-64765 grant to SM-F. This research was partly funded by a European Hematology Association Research Fellowship awarded to AS-A and an International Early Career Scientist Grant from the Howard Hughes Medical Institute to SM-F.S
Monitoring cell monolayers during electroporation: Electrical impedance spectroscopy measurements
Peer Reviewe
Shifting cultivation and hunting across the savanna-forest mosaic in the Gran Sabana, Venezuela: Facing changes
Background. Human encroachment and overexploitation of natural resources in the Neotropics is constantly increasing. Indigenous communities all across the Amazon, are trapped between a population rise and a hot debate about the sustainability of hunting rates. The Garden Hunting hypothesis states that shifting cultivation schemes (conucos) used by Amazon indigenous communities may generate favorable conditions, increasing abundance of small and medium wildlife species close to the `gardens' providing game for indigenous hunters. Methods. Here, we combined camera trap surveys and spatially explicit interview dataset on Pemón indigenous hunting scope and occurrence in a mosaic of savanna and forest in the Gran Sabana, Venezuela to evaluate to what extent the wildlife resource use corresponds to Garden Hunting hypothesis. We applied the Royle_Nichols model and binomial regression in order to: (1) assess whether abundance of small and medium wildlife species is higher close to conucos and (2) evaluate whether hunters select hunting localities based on accessibility to wildlife resources (closeness to conuco) more than wildlife abundance. Results. We find mixed evidence supporting the Garden Hunting hypothesis predictions. Abundance of small and medium species was high close to conucos but the pattern was not statistically significant for most of them. Pemón seem to hunt in locations dominated by forest, where species abundance was predicted to be higher, than in close vicinity to conucos. Hunting scope was focused on the most abundant species located close to the conuco (Cuniculus paca), but also in less abundant and unavailable species (Crax alector, Tapirus terrestris and Odocoileus virginianus). Conclusions. Our research provided the first attempt of a systematic sampling survey in the Gran Sabana, generating a quantitative dataset that not only describes the current pattern of wildlife abundance, but sets the base-line to monitor temporal and spatial change in this region of highland Amazon. We discuss the applicability of the estimates generated as a baseline as well as, environmental challenges imposed by economic, social and cultural changes such as mining encroachment for wildlife management. Subjects Anthropology, Biodiversity, Conservation Biology, Ecology, Natural Resource Management
Respuesta productiva en primer alevinaje de trucha cabeza de acero (Oncorhynchus mykiss) de ovas premium con dos alimentos extruidos
Universidad Nacional Agraria La Molina. Facultad de Zootecnia. Departamento Académico de NutriciónEl objetivo fue evaluar la respuesta productiva de dos alimentos balanceados extruidos en la primera etapa de alevines de trucha cabeza de acero (Oncorhynchus mykiss). El experimento se realizó en los estanques de la ecloseria Vinchos, situado en el distrito de Canchayllo provincia de Jauja región Junin, perteneciente a la SAIS “Túpac Amaru” Ltda. N°1. Los alimentos balanceados utilizados en el experimento fueron: El alimento extruido la Molina (T1) que se realiza en la Planta de Alimentos Balanceados de la Universidad Nacional Agraria La Molina, y el alimento extruido Nicovita (T2) de la empresa Vitapro. La evaluación se realizó durante 64 días, para lo cual se utilizaron 85836 alevines de trucha cabeza de acero con peso promedio de 142 gr. Estos peces experimentales fueron distribuidos en dos tratamientos con tres repeticiones de 14306 peces cada uno. Los parámetros de evaluación fueron ganancia de biomasa, consumo de alimento, conversión alimentaria, sobrevivencia, tasa de crecimiento y costo por kilogramo ganado. El modelo estadístico empleado fue el Diseño Completamente al Azar (D.C.A.), se realizó el análisis de varianza y la prueba de Tukey para evaluar las diferencias entre los promedios de los tratamientos y para el parámetro sobrevivencia se utilizó chi-cuadrado. Los resultados obtenidos para los parámetros evaluados consumo de alimento, conversión alimenticia, sobrevivencia y costo de alimentación mostraron diferencias significativas (α<0.05); sin embargo, en los parámetros, ganancia de peso y tasa de crecimiento, solo se observa un mayor rendimiento numérico al tratamiento 2 (T2). En conclusión, los resultados obtenidos indican que se obtuvo una mejor respuesta productiva con el tratamiento 1 (T1) por obtener un mayor porcentaje de sobrevivencia y menor costo por kilogramo ganado en la primera etapa de alevines de trucha cabeza de acero.The objective was to evaluate the productive response of two extruded balanced feeds in the first stage of steelhead trout fries (Oncorhynchus mykiss). The experiment was carried out in the ponds of the Vinchos hatchery, located in the district of Canchayllo, province of Jauja, region Junín, belonging to the SAIS “Túpac Amaru” Ltda. N°1. The balanced foods used in the experiment were: La Molina extruded food (T1) that is made in the Balanced Food Plant of the La Molina National Agrarian University, and Nicovita extruded food (T2) from the Vitapro S.A company. The evaluation was carried out during 64 days, for which 85,836 steelhead trout fingerlings with an average weight of 142 g were used. These experimental fish were distributed in two treatments with three repetitions of 14,306 fish each. The evaluation parameters were biomass gain, feed intake, feed conversion, survival, growth rate and cost per kilogram gained. The statistical model used was the Completely Random Design (D.C.A.), the analysis of variance and the Tukey test were performed to evaluate the differences between the means of the treatments and for the survival parameter, the chisquare was used. The results obtained for the evaluated parameters feed intake, feed conversion, survival and cost per kilogram gained showed significant differences (α<0.05); however, in the parameters, weight gain and growth rate, only a higher numerical performance is observed for treatment 2 (T2). In conclusion, the results obtained indicate that a better productive response was obtained with treatment 1 (T1) by obtaining a higher percentage of survival and lower cost per kilogram gained in the first stage of steelhead trout fries
- …