898 research outputs found
Monitoring degradation mechanisms in PTB7:PC71BM photovoltaic cells by means of impedance spectroscopy
© 2016. This version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/We have used impedance spectroscopy technique to monitor degradation mechanisms in organic solar cells based on a blend of PTB7:PC71BM. We have measured the impedance of the cell on a periodical basis for almost four months, and experimental data have been modeled using three different circuits. The evolution of the circuital parameters gives information about the device dynamical mechanisms. We have observed at high voltages a low frequency feature that is more pronounced along days of measurement. This low frequency arc has been associated to charge accumulation that is related to a worsening of charge extraction through the contacts. The simultaneous increase of recombination and low frequency resistances at high voltages (around V-oc) results in a decrease of the fill factor and therefore of the efficiency.Peer ReviewedPostprint (author's final draft
Towards more circular office fit-outs: a socio-technical descriptive framework of office fit-out processes
Ethyl (S)-3-hydroxybutyrate ((S)-E3HB) is naturally found as part of kiwi fruit aroma and is an important
precursor for the production of several pharmaceuticals. (S)-E3HB can be produced in a whole cell
biotransformation process from Ethylacetoacetate (EAA) using the yeast Saccharomyces cerevisiae. One way
of improving the sustainability of such processes may be their integration into novel biorefinery concepts, which
requires research to characterize the process and the byproduct formation. In this study it could be shown that
(S)-E3HB biocatalysis with S. cerevisiae can be performed under anaerobic conditions with production rates
between 4.0 × 10-3 and 2.5 × 10-2 g(S)-E3HB gbiomass
-1 h-1 which are similar to the rates in conventional aerobic
processes. The byproduct spectrum allows for the integration of the new anaerobic biotransformation process
into a recently invented biorefinery concept in which the side product CO2 is further utilized to produce methane
Evidence on equity, governance and financing after health care reform in Mexico: lessons for Latin American countries
This article includes evidence on equity, governance and health financing outcomes of the Mexican health system. An evaluative research with a cross-sectional design was oriented towards the qualitative and quantitative analysis of financing, governance and equity indicators. Taking into account feasibility, as well as political and technical criteria, seven Mexican states were selected as study populations and an evaluative research was conducted during 2002-2010. The data collection techniques were based on in-depth interviews with key personnel (providers, users and community leaders), consensus technique and document analysis. The qualitative analysis was done with ATLAS TI and POLICY MAKER softwares. The Mexican health system reform has modified dependence at the central level; there is a new equity equation for resources allocation, community leaders and users of services reported the need to improve an effective accountability system at both municipal and state levels. Strategies for equity, governance and financing do not have adequate mechanisms to promote participation from all social actors. Improving this situation is a very important goal in the Mexican health democratization process, in the context of health care reform. Inequality on resources allocation in some regions and catastrophic expenditure for users is unequal in all states, producing more negative effects on states with high social marginalization. Special emphasis is placed on the analysis of the main strengths and weaknesses, as relevant evidences for other Latin American countries which are designing, implementing and evaluating reform strategies in order to achieve equity, good governance and a greater financial protection in health
Buenas prácticas ganaderas en hatos lecheros de Santa Rosa de Cabal, Risaralda, Colombia
The objective of the present study was to analyze the degree of compliance of these practices, by evaluation of 99 variables in 21 productive systems in Santa Rosa de Cabal, Risaralda. Only one of the farms complied with the 48 fundamental criteria required and, the degree of compliance of major and minor criteria was insufficient. Only 8 of the farms are certified as free of brucellosis and tuberculosis. The best performing areas are animal welfare (81%) and those related to the milking routine (79.1%); On the other hand, the most deficient were the control of veterinary drugs and agricultural products (5.8%), as well as the conditions of the cooling tank (32.6%). Through a Multiple Correspondence Analysis, a significant association was found between variables involved with the guarantee in the safety of the milk, regarding the operation, cleaning and disinfection of equipment that guarantee an adequate temperature. There was also an association between variables involved in the milking procedure and hygienic conditions during the milking procedure, involving both the operator and the animal. A lack of training and awareness about the importance of compliance with many of these criteria was found, this is a fundamental tool to obtain a diagnosis of the current sanitary status, and in which it may be necessary to take into account other variables, not included in the current checklist, for a later implementation and follow-up to improvement plans of the productive systems.El objetivo del presente trabajo fue analizar el grado de cumplimiento de BPG, mediante la evaluación de 99 variables en 21 sistemas productivos del municipio de Santa Rosa de Cabal, Risaralda. Solo uno de los predios cumplió con los 48 criterios fundamentales exigidos y en general, el grado de cumplimiento de criterios mayores y menores fue insuficiente. Solo 8 de los hatos están certificados como libres de brucelosis y tuberculosis. Las áreas de mejor desempeño son el bienestar animal (81%) y las relacionadas con la rutina de ordeño (79,1%); en cambio, las mas deficientes fueron el control de medicamentos veterinarios e insumos agropecuarios (5,8%), asà como las condiciones del tanque de enfriamiento (32,6%). Mediante un Análisis de Correspondencia múltiple, se encontró asociación significativa entre variables que tienen que ver con la garantÃa en la inocuidad de la leche, en lo referente a la operación, limpieza y desinfección de equipos que garanticen una temperatura adecuada. También hubo asociación entre variables que tienen que ver con el procedimiento de ordeño y condiciones de higiene durante la faena, que involucran tanto al operario, como al animal. Se evidencia falta de capacitación y concientización acerca de la importancia del cumplimiento de muchos criterios de BPG, que es una herramienta fundamental para obtener un diagnostico del estado actual del hato, y en la cual posiblemente sea necesario tener en cuenta otras variables, no incluidas en la lista de verificación actual, para una posterior implementación y seguimiento a planes de mejoramiento de los sistemas productivos
Mejoramiento del porcentaje de proteina en maiz para ensilaje con el aumento y parcializaci 3n de la fertilizacion nitrogenada
In clay soils with poor drainage two trials were carried out with the
objective of determining the effect of nitrogen application on maize
(Zea mays L.) for silage on forage yield and protein content. In Trial
1, the treatments were two corn silage hybrids of different growing
periods, SX-43 and INIA-150, sown at 90.000 plants ha-1 and four N
rates: 0, 100, 200 and 400 kg N ha-1. In Trial 2, the treatments were
two N rates: 200 and 400 kg of N ha-1, and three forms of N
application: a) 1/2 at sowing + 1/2 at 30 cm plant height; b) 1/3 at
sowing + 1/3 at 30 cm plant height + 1/3 at 60 cm plant height; and c)
1/4 at sowing + 1/4 at 30 cm plant height + 1/4 at 60 cm plant height
+1/4 at flowering. One treatment was without N. In Trial 1 N
application increased DM yield (P < 0.05), but no significant
response was observed with N rates between 100 and 400 kg N ha-1, due
to soil limitations. Forage production and protein percentage increased
significantly with N application. In Trial 2, DM production in corn
silage increased with higher N rates (P < 0.05). Forage protein
percentage was increased by higher N rates and partitioning of the
application. On increasing the partitioning of N from two to four
applications, protein percentage of forage was increased by 23 and 37%
for 200 and 400 kg of N ha-1, respectively.En suelos arcillosos de mal drenaje se realizaron dos ensayos con el
objetivo de determinar la respuesta de ma\uedz (Zea mays L.) para
ensilaje a la aplicaci\uf3n de N en el rendimiento y contenido de
prote\uedna del forraje. En el Ensayo 1 los tratamientos
correspondieron a dos h\uedbridos de ma\uedz para ensilaje de
distinta precocidad, SX-43 e INIA-150, sembrados con una poblaci\uf3n
de 90.000 plantas ha-1 y cuatro dosis de N: 0, 100, 200 y 400 kg N
ha-1. En el Ensayo 2, los tratamientos fueron dos dosis de N: 200 y 400
kg N ha-1, y tres formas de aplicaci\uf3n de nitr\uf3geno: a) 1/2 a
la siembra + 1/2 a 30 cm de altura de las plantas; b) 1/3 a la siembra
+ 1/3 a 30 cm de altura de las plantas + 1/3 a 60 cm de altura de
plantas; y c) 1/4 a la siembra + 1/4 a 30 cm de altura de las plantas +
1/4 a 60 cm de altura de plantas +1/4 en floraci\uf3n. Adem\ue1s se
incluy\uf3 un tratamiento sin aplicaci\uf3n de N. En el Ensayo 1,
la aplicaci\uf3n de N aument\uf3 el rendimiento de MS (P <
0,05), sin embargo no hubo respuesta significativa entre 100 y 400 kg
de N, debido a limitantes de suelo. La producci\uf3n y el porcentaje
de prote\uedna del forraje aument\uf3 significativamente con la
aplicaci\uf3n de N. En el Ensayo 2, la producci\uf3n de MS en el
ma\uedz aument\uf3 con la aplicaci\uf3n de N (P < 0,05). El
porcentaje de prote\uedna del forraje se increment\uf3 con mayores
dosis de N y su parcializaci\uf3n. Al aumentar la parcializaci\uf3n
del N de 2 a 4 aplicaciones se increment\uf3 el tenor proteico del
forraje en 23 y 37 % para las dosis de 200 y 400 kg N ha-1,
respectivamente
Small Unmanned Aerial Vehicles (Micro-UAVs, Drones) in Plant Ecology
Premise of the study: Low-elevation surveys with small aerial drones (micro–unmanned aerial vehicles [UAVs]) may be used for a wide variety of applications in plant ecology, including mapping vegetation over small- to medium-sized regions. We provide an overview of methods and procedures for conducting surveys and illustrate some of these applications.
Methods: Aerial images were obtained by flying a small drone along transects over the area of interest. Images were used to create a composite image (orthomosaic) and a digital surface model (DSM). Vegetation classification was conducted manually and using an automated routine. Coverage of an individual species was estimated from aerial images.
Results: We created a vegetation map for the entire region from the orthomosaic and DSM, and mapped the density of one species. Comparison of our manual and automated habitat classification confirmed that our mapping methods were accurate. A species with high contrast to the background matrix allowed adequate estimate of its coverage.
Discussion: The example surveys demonstrate that small aerial drones are capable of gathering large amounts of information on the distribution of vegetation and individual species with minimal impact to sensitive habitats. Low-elevation aerial surveys have potential for a wide range of applications in plant ecology
Mutations in LAMB2 causing a severe form of synaptic congenital myasthenic syndrome
BackgroundWe describe a severe form of congenital myasthenic syndrome (CMS) associated with congenital nephrosis and ocular malformations caused by two truncating mutations in the gene encoding the laminin beta2 subunit (LAMB2).Methods and resultsMutational analysis in the affected patient, who has a history of a serious untoward reaction to treatment with acetylcholinesterase inhibition, revealed two frame-shifting heteroallelic mutations, a maternally inherited 1478delG and a paternally inherited 4804delC. An anconeus muscle biopsy demonstrated a profound distortion of the architecture and function of the neuromuscular junction, which was strikingly similar to that seen in mice lacking laminin beta2 subunit. The findings included: pronounced reduction of the axon terminal size with encasement of the nerve endings by Schwann cells, severe widening of the primary synaptic cleft and invasion of the synaptic space by the processes of Schwann cells, and moderate simplification of postsynaptic folds and intact expression of the endplate acetylcholinesterase. The endplate potential quantal content was notably reduced, while the frequencies and amplitudes of miniature endplate potentials were only moderately diminished and the decay phases of miniature endplate potentials were normal. Western blot analysis of muscle and kidney tissue and immunohistochemistry of kidney tissue showed no laminin beta2 expression.ConclusionThis case, which represents a new type of synaptic CMS, exemplifies the wide variability of phenotypes associated with LAMB2 mutations and underscores the fundamental role that laminin beta2 plays in the development of the human neuromuscular junction
Integration issues on tritium management of the European DEMO Breeding Blanket and ancillary systems
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