1,124 research outputs found
Determinants of internal medicine residents' choice in the canadian R4 Fellowship Match: A qualitative study
<p>Abstract</p> <p>Background</p> <p>There is currently a discrepancy between Internal Medicine residents' decisions in the Canadian subspecialty fellowship match (known as the R4 match) and societal need. Some studies have been published examining factors that influence career choices. However, these were either demographic factors or factors pre-determined by the authors' opinion as possibly being important to incorporate into a survey.</p> <p>Methods</p> <p>A qualitative study was undertaken to identify factors that determine the residents choice in the subspecialty (R4) fellowship match using focus group discussions involving third and fourth year internal medicine residents</p> <p>Results</p> <p>Based on content analysis of the discussion data, we identified five themes:</p> <p indent="1">1) Practice environment including acuity of practice, ability to do procedures, lifestyle, job prospects and income</p> <p indent="1">2) Exposure in rotations and to role models</p> <p indent="1">3) Interest in subspecialty's patient population and common diseases</p> <p indent="1">4) Prestige and respect of subspecialty</p> <p indent="1">5) Fellowship training environment including fellowship program resources and length of training</p> <p>Conclusions</p> <p>There are a variety of factors that contribute to Internal Medicine residents' fellowship choice in Canada, many of which have been identified in previous survey studies. However, we found additional factors such as the resources available in a fellowship program, the prestige and respect of a subspecialty/career, and the recent trend towards a two-year General Internal Medicine fellowship in our country.</p
Purple nustedge (Cyperus rotundus L.) control through climbing legumes such as Mucuna pruriens L. and Lablab purpureus L.
The adoption of Conservation Agriculture in Mozambique poses new challenges for smallholder farmers. One of these challenges is the control of perennial weeds without herbicides which is beyond the reach of this group of farmers in Cabo Delgado due to: a) High prices (low-income farmers), and
b) Cabo Delgado is a remote area where aff ordable access to herbicides and other inputs is not yet possible. Looking for sustainable solutions according to local agro-ecological and socio-economic conditions of the region was the aim of the on-farm research carried out. The present study aimed at testing the effi ciency of two cover crops, Mucuna pruriens L. and Lablab purpureus L. in the
control of purple nustedge (Cyperus rotundos L.) in Conservation Agriculture systems. The trials were conducted in the village of Nangua, in the province of Cabo Delgado during the rainy seasons of 2014/15 and 2015/16 crop years in a field that was abandoned due to purple nustedge weed
infestation. Two cover crops, mucuna and lablab, were established in 12 m² plots, in three replications.
Three counts of the quantity of purple nustedge were made in these plots: 1st count, 1 day before sowing; 2nd count, 30 days after germination, and 3rd count, 60 days after germination. Before the cover crops were sown, the purple nustedge counts were made in 1 m² area in 2 sites located in each plot, during two seasons. In the first year, there was a decrease in the number of plants of purple nustedge in the plots where both legumes were grown. Both legumes showed greater efficiency in the control of purple nustedge with increase in their duration in the field mainly between 30 days and 60 days after sowing. Results show that mucuna and lablab can replace each other in the control
of purple nustedge because the effect of the application of both cultures is indifferent. Mucuna and lablab usage as cover crop in Conservation Agriculture Systems favors dormancy of the bulbs and creates unfavorable conditions for the viability of purple nustedge seeds and thus decreases their
proliferation capacity in field crops
Overview of the Worldwide Spread of Conservation Agriculture
The global empirical evidence shows that farmer-led transformation of agricultural production systems based on Conservation Agriculture (CA) principles is already occurring and gathering momentum globally as a new paradigm for the 21st century. The data presented in this paper has been collected by the Food and Agriculture Organization of the United Nations from several sources including estimates made by ministries of agriculture, by farmer organizations, and well-informed individuals in research or development organizations; they provide an overview of CA adoption and spread by country, as well as the extent of CA adoption by continent. CA systems, comprising no or minimum mechanical soil disturbance, organic mulch soil cover, and crop species diversification, in conjunction with other good practices of crop and production management, are now (in 2013) practiced globally on about 157 M ha, corresponding to about 11% of field cropland, in all continents and most land-based agricultural ecologies, including in the various temperate environments. This change constitutes a difference of some 47% globally since 2008/09 when the spread was recorded as 106 M ha. The current total of 157 M ha represents an increase in adoption of CA by more countries but the estimate is on the conservative side as the updated database does not capture all the CA cropland. While in 1973/74 CA systems covered only 2.8 M ha worldwide, the area had grown in 1999, to 45 M ha, and by 2003 the area had grown to 72 M ha. In the last 10 years CA cropland has expanded at an average rate of more than 8.3 M ha per year and since 2008/2009 at the rate of some 10 M ha per year, showing the increased interest of farmers and national governments in this alternate production concept and method. Adoption has been intense mainly in North and South America as well as in Australia and Asia, and more recently in Europe and Africa where the awareness of and support for CA is on the increase. The paper presents an update of the adoption of CA since 2008/09.Au vu des données empiriques mondiales, la transformation des systèmes de production agricole, qui s’appuient sur les principes de l’Agriculture de Conservation (AC), conduite par les agriculteurs eux-mêmes, est déjà engagée et s’impose peu à peu comme un nouveau modèle mondial pour le 21ème siècle. Les données de cet article ont été recueillies par l'Organisation des Nations Unies pour l’Alimentation et l’Agriculture (FAO) auprès de plusieurs sources et sont notamment issues d'études réalisées par des ministères de l'agriculture, des organisations d'agriculteurs et des experts d'organismes de recherche et développement ; elles donnent un aperçu par pays et par continent du niveau d’adoption et de progression de l’AC. Les pratiques de l’AC, qui englobent la perturbation mécanique minimale, voire aucune perturbation mécanique du sol, l’utilisation des paillis organiques et la diversification des espèces cultivées, associées à d’autres bonnes pratiques de gestion des cultures et de la production, sont aujourd’hui (en 2013) mises en œuvre sur près de 157 millions d’hectares, soit près de 11 % des terres cultivées, sur tous les continents et dans la plupart des écologies agricoles, notamment dans les divers environnements tempérés. Cette évolution représente un écart de près de 47 % au niveau mondial par rapport aux années 2008/09, où l'AC était pratiquée sur 106 millions d’hectares. Le chiffre actuel de 157 millions d’hectares reflète une adoption plus large de l'AC dans un nombre croissant de pays mais il s'agit là d'une estimation prudente, la base de données actualisée ne prenant pas en compte la totalité des terres cultivées en AC. Alors que l'AC couvrait seulement 2,8 M ha dans le monde en 1973/74, elle s'est étendue à 45 M ha en 1999 et 72 M ha en 2003. Au cours des dix dernières années, la surface de terres cultivées en AC s’est développée à un rythme moyen de plus de 8,3 M ha par an et d'environ 10 M ha par an depuis 2008/2009, illustrant l’intérêt croissant des agriculteurs et des gouvernements pour ce concept et ces méthodes de production alternatifs. L'adoption de l'AC a été particulièrement soutenue en Amérique du Nord et en Amérique du Sud, ainsi qu'en Australie et en Asie, et, plus récemment, en Europe et en Afrique, où la sensibilisation aux principes de l'AC et l’encouragement de leur adoption ne cessent d'augmenter. Cet article présente un état des lieux de l'adoption de l'AC depuis 2008/09.Las pruebas empíricas a nivel mundial muestran que la transformación de los sistemas de producción agrícola guiada por los agricultores y basada en los principios de la agricultura de conservación ya se está produciendo y está cobrando impulso en todo el mundo como un nuevo paradigma para el siglo XXI. Los datos presentados en este trabajo han sido obtenidos por la Organización de las Naciones Unidas para la Agricultura y la Alimentación de varias fuentes, entre las que se incluyen las estimaciones realizadas por ministerios de agricultura, organizaciones de agricultores y otros entendidos en la materia de organizaciones de investigación o desarrollo, y proporcionan una perspectiva general de la adopción y la propagación de la agricultura de conservación por país, así como el alcance de la adopción de la agricultura de conservación en los distintos continentes. Los sistemas de agricultura de conservación, que incluyen una perturbación mecánica mínima o nula de la tierra, el uso de una capa de mantillo natural y la diversificación de las especies de cultivo, en combinación con otras prácticas positivas de gestión de cultivos y de la producción, se utilizan actualmente (en 2013) a nivel mundial en unos 157 millones de hectáreas, lo que corresponde aproximadamente al 11 % de las tierras de cultivo, en todos los continentes y la mayoría de las agroecologías basadas en el suelo, incluidos los ambientes templados. Este cambio constituye una diferencia de aproximadamente el 47 % en todo el mundo desde los años 2008-2009 cuando la propagación era de 106 millones de hectáreas. La cifra total actual de 157 millones de hectáreas representa un aumento en la adopción de la agricultura de conservación por parte de más países si bien esta estimación es conservadora ya que la base de datos actualizada no abarca todas las tierras de cultivo en las que se practica la agricultura de conservación. Mientras en los años 1973-1974 los sistemas de agricultura de conservación ocupaban solo 2,8 millones de hectáreas en el mundo, esta extensión fue creciendo hasta alcanzar los 45 millones de hectáreas en 1999 y los 72 millones de hectáreas en 2003. En los últimos 10 años las tierras de cultivo en las que se practica la agricultura de conservación se han extendido a un ritmo medio de más de 8,3 millones de hectáreas por año y desde los años 2008-2009 a un ritmo de unos 10 millones de hectáreas por año, lo que demuestra el creciente interés de los agricultores y los gobiernos nacionales en este concepto y método de producción alternativa. La adopción ha sido especialmente importante en América del Norte y del Sur, así como en Australia y Asia, y más recientemente en Europa y África, donde la concienciación y el apoyo a la agricultura de conservación son cada vez mayores. Este trabajo presenta información actualizada sobre la adopción de la agricultura de conservación desde los años 2008-2009
Assessment of apparent effectiveness of chemical egg disinfectants for improved artificial hatching in oreochromis karongae (pisces: cichlidae)
Oreochromis karongae is one of the three key Tilapia species locally known as ‘Chambo’ which is endemic to Lake Malawi. The species is favored by consumers and due to high demand its catches have significantly declined over time. Aquaculture holds the potential to supplement catches as well as produce seed for restocking purposes. However, seed production of O.karongae in artificial hatcheries has registered little success due to high egg and fry mortalities. Therefore, a study was conducted to compare the apparent effectiveness of three chemical egg disinfectants in an attempt to improve hatching success and reduce fry mortality in O. karongae in an artificial re-circulating incubation system at the National Aquaculture Center, Domasi, Malawi. Batches of 200 stage II eggs were immersed for 5 minutes in 50ml solutions of (1) 50mg/l Potassium Permanganate, (2) 500mg/l Formalin, (3) 1000mg/l Sodium Chloride, (4) 5000mg/l Sodium Chloride, while treatment (5) was a control without any chemical treatment. Each treatment was replicated three times in 1.2 L plastic incubation jars with continuous water flow rate of 0.17 l/s operated at 10% daily water replacement. There was significantly low total mortality and high hatchability in treatments (1), (2) and (3) than (4) and (5) (p<0.05). The results provided evidence that pre-incubation egg treatment using chemicals has potential to significantly reduce mortalities and increase fry production in an artificial re-circulating incubation system. It is recommended, based on the findings that lower concentrations of sodium chloride, being a safer and less toxic chemical can be used for disinfecting O.karongae eggs. Future studies should focus on undertaking a toxicity test with various levels of the chemical disinfectants to identify optimum doses. This should be coupled with microbiological assays to validate the apparent effectiveness found in this study and identify the key microbial species that are responsible for mortalities during incubation of O.karongae eggs in a re-circulating system.Key words: Egg, disinfectants, incubation, recirculation, hatchability, egg treatment, mortality, Oreochromis karonga
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Rethinking energy security and services in practice: national vulnerability and three energy pathways in Tajikistan
To help answer questions about availability, accessibility, sustainability and other dimensions of energy security, the vulnerability approach concentrates the attention of policymakers on the assessment of risks associated with natural, technical, political and economic factors. This understanding, combined with a focus on energy services (e.g. lighting, heating, telecommunications, mobility, etc.) helps to prioritize actions to achieve the goal of energy security. This paper conceptualizes energy security as low vulnerability of vital energy systems and sustained provision of modern energy services. Taking Tajikistan as a case, this paper highlights key vulnerabilities including neglect of environmental conditions, insufficient energy production capacity, unreliable and expensive energy imports, dwindling power infrastructure causing technical and economic losses, inadequate transparency in the power sector, lack of regional cooperation in energy and water resources sharing, and inadequate financial resources to address these challenges. Three major proposals presented by the World Bank, the United Nations Development Program, and the Government of Tajikistan to achieve energy security in Tajikistan are evaluated. Specifically, they lack a focus on energy services and therefore overlook people's socio-cultural context and appropriate energy needs. This paper highlights energy services as critical to people’s wellbeing and socio-economic development
Design and Implementation of Near-Field, Wideband Synthetic Aperture Beamformers
A coarray-based near-field, wideband synthetic aperture beamformer using stepped-frequency signal synthesis and post-data acquisition processing is presented. While coarray techniques offer significant reduction in the number of array elements for a given angular resolution, the hybrid subarray-stepped frequency realization of wideband systems simplifies implementations and offers flexibility in beamforming. Proof of concept is provided using real data collected in an anechoic chamber for several pulse shapes and array weightings
A Wideband, Synthetic Aperture Beamformer for Through-The-Wall Imaging
A coarray-based aperture synthesis scheme using subarrays and post-data acquisition beamforming is presented for through-the-wall wideband microwave imaging applications. Various effects of the presence of the wall, such as refraction, change in speed, and attenuation, are incorporated into the beamformer design. Simulation results verifying the proposed synthetic aperture technique for a TWI system are presented. The effects of incorrect estimates of the parameters of the wall, such as thickness and dielectric constant, on performance are investigated
A New Approach for Near-Field Wideband Synthetic Aperture Beamforming
A coarray-based synthetic aperture beamformer using stepped-frequency signal synthesis and post-data acquisition processing is presented for wideband imaging of near-field scenes. The proposed beamformer formulation and implementation finds key applications in through-the-wall microwave imaging and landmine detection problems. While coarray techniques offer significant reduction in array elements for a given angular resolution, stepped-frequency realization of wideband systems simplifies implementation and offers flexibility in beamforming. Proof of concept is provided using real data collected in an anechoic chamber
Application of the Gaussian mixture model in pulsar astronomy -- pulsar classification and candidates ranking for {\it Fermi} 2FGL catalog
Machine learning, algorithms to extract empirical knowledge from data, can be
used to classify data, which is one of the most common tasks in observational
astronomy. In this paper, we focus on Bayesian data classification algorithms
using the Gaussian mixture model and show two applications in pulsar astronomy.
After reviewing the Gaussian mixture model and the related
Expectation-Maximization algorithm, we present a data classification method
using the Neyman-Pearson test. To demonstrate the method, we apply the
algorithm to two classification problems. Firstly, it is applied to the well
known period-period derivative diagram, where we find that the pulsar
distribution can be modeled with six Gaussian clusters, with two clusters for
millisecond pulsars (recycled pulsars) and the rest for normal pulsars. From
this distribution, we derive an empirical definition for millisecond pulsars as
. The two
millisecond pulsar clusters may have different evolutionary origins, since the
companion stars to these pulsars in the two clusters show different chemical
composition. Four clusters are found for normal pulsars. Possible implications
for these clusters are also discussed. Our second example is to calculate the
likelihood of unidentified \textit{Fermi} point sources being pulsars and rank
them accordingly. In the ranked point source list, the top 5% sources contain
50% known pulsars, the top 50% contain 99% known pulsars, and no known active
galaxy (the other major population) appears in the top 6%. Such a ranked list
can be used to help the future follow-up observations for finding pulsars in
unidentified \textit{Fermi} point sources.Comment: 9 pages, 4 figures, accepted by MNRA
Proceedings of the 8th World Congress on Conservation Agriculture
Under the banner: The Future of Farming – Profitable and Sustainable Farming with
Conservation Agriculture, the 8WCCA highlighted the global contribution of Conservation Agriculture towards achieving these outcomes. It also explored how CA land use can help to address humankind’s major global challenges of climate change, environmental degradation and food security
while safeguarding the livelihoods of small and large-scale farmers. The proven benefits of CA in terms of erosion control, carbon sequestration, biodiversity regeneration, and improved water and nutrient cycling are all contributing to the achievement of the manifold objectives of the international conventions and agreements including the
Sustainable Development Goals, European
Green Deal and F2F Strategy
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