Impact of pesticides on indicator and pathogenic microorganism persistence under laboratory and field conditions

On s’intéresse aux impacts des pesticides sur la microflore des plantes surtout dans le contexte des légumes contaminés par des agents pathogènes. Le but de cette étude est d'évaluer l'impact de certains pesticides sur la persistance de micro-organismes indicateurs et pathogènes. En laboratoire, la persistance d’E. coli et de Salmonella en présence de quatre pesticides (Ripcord 400EC, Copper 53W, Bioprotec CAF, Serenade MAX) a été étudiée. Les plaques de Pétrifilm et le milieu sélectif XLD sont utilisés pour énumérer les populations d’E. coli et de Salmonella. Il a été démontré que le Serenade MAX favorisait la croissance microbienne, le Bioprotec CAF et le Ripcord 400EC soutenaient la survie microbienne et le Copper 53W inhibait la croissance, à la fois d’E. coli et de Salmonella. En conditions terrain, Ripcord 400EC, Copper 53W, Bioprotec CAF ont été étudiés sur une culture de brocoli irriguée avec de l'eau expérimentalement contaminée par E. coli. Dans tous les traitements, un impact de l’irrigation a été observé sur les populations de levures et de moisissures (diminution) et les bactéries aérobies totales (augmentation). Une prévalence supérieure d’E. coli a été observée dans les parcelles traitées avec le Bioprotec CAF comparativement aux traitements au Copper 53W, ce qui est en accord avec les résultats observés lors de l'essai en laboratoire. Cependant, l'analyse statistique n'a montré aucune différence significative entre les traitements appliqués. Les effets directs des pesticides sur les micro-organismes sont confirmés dans des conditions de laboratoire mais demeurent méconnus dans les conditions expérimentales au champ.

Effects of manure quality and application forms on soil C and N turnover of a subtropical oasis soil under laboratory conditions

Our knowledge of the agricultural sustainability of the millennia-old mountain oases in northern Oman is restricted in particular with respect to C and N turnover. A laboratory study was conducted (1) to analyse the effects of rewetting and drying on soil microorganisms after adding different manures, (2) to investigate the effects of mulching or incorporating of these manures, and (3) to evaluate the relationships between C and N mineralisation rates and manure quality indices. During the first 9-day rewetting and drying cycle, i.e. the “mulch” period, the content of extractable organic C decreased by approximately 40% in all four treatments. During the second 9-day rewetting and drying cycle, i.e. the “incorporation” period, this fraction decreased insignificantly in almost all treatments. The control and mature manure treatments form the first pair with a low percentage of total organic C evolved as CO2 (0.3% in 18 days) and a considerable percentage of total N mineralised as NH4 and NO3 (1% in 18 days), the fresh and immature manure treatments form the second pair with a higher amount of total organic C evolved as CO2 (0.5% in 18 days) and no net N mineralisation. During the first 9-day rewetting and drying cycle, the contents of microbial biomass C and biomass N increased by approximately 150% in all four treatments. During the second 9-day rewetting and drying cycle, no further increase was observed in the control and immature manure treatments and a roughly 30% increase in the other two treatments.

Determination of yield and quality parameters of energy crops applying laboratory and field spectroscopy

A real-time analysis of renewable energy sources, such as arable crops, is of great importance with regard to an optimised process management, since aspects of ecology and biodiversity are considered in crop production in order to provide a sustainable energy supply by biomass. This study was undertaken to explore the potential of spectroscopic measurement procedures for the prediction of potassium (K), chloride (Cl), and phosphate (P), of dry matter (DM) yield, metabolisable energy (ME), ash and crude fibre contents (ash, CF), crude lipid (EE), nitrate free extracts (NfE) as well as of crude protein (CP) and nitrogen (N), respectively in pretreated samples and undisturbed crops. Three experiments were conducted, one in a laboratory using near infrared reflectance spectroscopy (NIRS) and two field spectroscopic experiments. Laboratory NIRS measurements were conducted to evaluate to what extent a prediction of quality parameters is possible examining press cakes characterised by a wide heterogeneity of their parent material. 210 samples were analysed subsequent to a mechanical dehydration using a screw press. Press cakes serve as solid fuel for thermal conversion. Field spectroscopic measurements were carried out with regard to further technical development using different field grown crops. A one year lasting experiment over a binary mixture of grass and red clover examined the impact of different degrees of sky cover on prediction accuracies of distinct plant parameters. Furthermore, an artificial light source was used in order to evaluate to what extent such a light source is able to minimise cloud effects on prediction accuracies. A three years lasting experiment with maize was conducted in order to evaluate the potential of off-nadir measurements inside a canopy to predict different quality parameters in total biomass and DM yield using one sensor for a potential on-the-go application. This approach implements a measurement of the plants in 50 cm segments, since a sensor adjusted sideways is not able to record the entire plant height. Calibration results obtained by nadir top-of-canopy reflectance measurements were compared to calibration results obtained by off-nadir measurements. Results of all experiments approve the applicability of spectroscopic measurements for the prediction of distinct biophysical and biochemical parameters in the laboratory and under field conditions, respectively. The estimation of parameters could be conducted to a great extent with high accuracy. An enhanced basis of calibration for the laboratory study and the first field experiment (grass/clover-mixture) yields in improved robustness of calibration models and allows for an extended application of spectroscopic measurement techniques, even under varying conditions. Furthermore, off-nadir measurements inside a canopy yield in higher prediction accuracies, particularly for crops characterised by distinct height increment as observed for maize.

Evaluation of major feed resources in crop-livestock mixed farming systems, southern Ethiopia: Indigenous knowledge versus laboratory analysis results

Evaluation of major feed resources was conducted in four crop-livestock mixed farming systems of central southern Ethiopia, with 90 farmers, selected using multi-stage purposive and random sampling methods. Discussions were held with focused groups and key informants for vernacular name identification of feed, followed by feed sampling to analyse chemical composition (CP, ADF and NDF), in-vitro dry matter digestibility (IVDMD), and correlate with indigenous technical knowledge (ITK). Native pastures, crop residues (CR) and multi-purpose trees (MPT) are the major feed resources, demonstrated great variations in seasonality, chemical composition and IVDMD. The average CP, NDF and IVDMD values for grasses were 83.8 (ranged: 62.9–190), 619 (ranged: 357–877) and 572 (ranged: 317–743) g kg^(−1) DM, respectively. Likewise, the average CP, NDF and IVDMD for CR were 58 (ranged: 20–90), 760 (ranged: 340–931) and 461 (ranged: 285–637)g kg^(−1) DM, respectively. Generally, the MPT and non-conventional feeds (NCF, Ensete ventricosum and Ipomoea batatas) possessed higher CP (ranged: 155–164 g kg^(−1) DM) and IVDMD values (611–657 g kg^(−1) DM) while lower NDF (331–387 g kg^(−1) DM) and ADF (321–344 g kg^(−1) DM) values. The MPT and NCF were ranked as the best nutritious feeds by ITK while crop residues were the least. This study indicates that there are remarkable variations within and among forage resources in terms of chemical composition. There were also complementarities between ITK and feed laboratory results, and thus the ITK need to be taken into consideration in evaluation of local feed resources.

A Self-Scoring Exercise On APA Style, Research Language, and Referencing for Undergraduate Students

Based on examples provided by 27 graduate psychology faculty, this self-test incorporates many of the more common errors in style, language, and referencing found in student papers. Taking this self-test helps students to recognize common errors and encourages them to refer the APA Publication Manual on a regular basis. In addition, students begin to think about how to use correctly the language of psychological research. This self-test should take about 30 minutes to complete and score. It is composed of three parts: a) a mock Discussion section, where students are asked to act as editors and find the errors, p. 2 (10 minutes). b) a corrected Discussion section, where students find the errors they missed, p. 3 (5 minutes) and, c) a full description of each error with illustrations of correct usage, pp. 4-7 (15 minutes). This exercise assumes some knowledge of APA style. Thus, it is best-suited for advanced undergraduates who need to write research reports and all levels of graduate students. It may be taken at home or in class. Although the self-test is designed to be fully self-directed, instructors may wish to use it at the beginning or end of a classroom discussion on APA style. It could also be used in a pre-test-post-test fashion to evaluate students learning over the course of a term.

Laboratory on Matlab

Considers various basic features of Matlab

Laboratory on Matlab

Considers function handles, matrix manipulation, 3D plots and programming

Educating an iPod generation: undergraduate attitudes, experiences and understanding of vodcast and podcast use

ognyline) There is an increasing pressure on university staff to provide ever more information and resources to students. This study investigated student opinions on (audio) podcasts and (video) vodcasts and how well they met requirements and aided learning processes. Two experiments within the Aston University looked at student opinion on, and usage of, podcasts and vodcasts for a selection of their psychology lectures.

Evaluación del nivel de seguridad ocupacional en laboratorios universitarios de ingeniería en Bogotá

Antecedentes: Los laboratorios estudiantiles ofrecen riesgos para los estudiantes, la normatividad específica vigente no es de carácter obligatorio y en Bogotá aproximadamente hay 387 laboratorios. Objetivo: Evaluar el nivel de seguridad referente a salud, higiene y seguridad industrial en las prácticas que se desarrollan en los laboratorios de pregrado de Ingeniería en universidades de Bogotá. Métodos: Estudio descriptivo con un muestreo estratificado por conglomerado en ocho (8) universidades de la ciudad de Bogotá, con una confiabilidad del 95% y una precisión absoluta del 6% para una proporción máxima esperada; para evaluar los laboratorios se utilizó el Cuestionario de seguridad para laboratorios de secundaria (NTP 921) del Instituto Nacional de Seguridad e Higiene del Trabajo de España Resultados: Se evaluaron 166 laboratorios de 8 universidades de Bogotá, 65 de los laboratorios evaluados presentaron un riesgo bajo de los aspectos evaluados. Los aspectos con un porcentaje mayor o igual al 80% de cumplimiento de condiciones fueron aspectos generales del laboratorio, trabajo de los alumnos, manipulación de material, manipulación del producto, protección contra Incendios, eliminación de residuos, seguridad eléctrica y formación. Los ítems con un porcentaje menor del 60% de cumplimiento son los siguientes: sistemas de alarma contra incendios o emergencias; mantenimiento preventivo de la red eléctrica del laboratorio, capacitaciones anuales sobre seguridad en los laboratorios. aspectos generales del laboratorio, trabajo de los alumnos, manipulación de material, manipulación del producto, protección contra Incendios, eliminación de residuos, seguridad eléctrica y formación. Se realizó una prueba de asociación entre el tipo de laboratorio y cada ítem de las condiciones de seguridad del laboratorio. Los laboratorios que cumplen con un mayor número de condiciones de seguridad fueron los laboratorios químicos, el aspecto que obtuvo un porcentaje bajo de cumplimiento fue protección personal (40%); los aspectos que se cumplieron son aspectos generales del laboratorio, trabajo de los alumnos, manipulación de material, manipulación del producto, protección contra Incendios, eliminación de residuos, seguridad eléctrica y formación.

Bibliography profiling of undergraduate theses in a professional psychology program

The bibliographic profile of 125 undergraduate (licentiate) theses was analyzed, describing absolute quantities of several bibliometric variables, as well as within-document indexes and average lags of the references. The results show a consistent pattern across the years in the 6 cohorts included in the sample (2001-2007), with variations, which fall within the robust confi dence intervals for the global central tendency. The median number of references per document was 52 (99% CI 47-55); the median  percentage of journal articles cited was 55%, with a median age for journal references of 9 years. Other highlights of the bibliographic profile were the use of foreign language references (median 61%), and low reliance on open web documents (median 2%). A cluster analysis of the bibliometric indexes resulted  in a typology of 2 main profiles, almost evenly distributed, one of them with the makeup of a natural science bibliographic profile and the second within the style of the humanities. In general, the number of references, proportion of papers, and age of the references are close to PhD dissertations and Master theses, setting a rather high standard for undergraduate theses.

Evaluation of the Toxic Effect from Eupatorium Microphyllum L.F. (Asteraceae) Extracts on Aedes Aegypti Larvae (Diptera: Culicidae) in Laboratory Conditions

In the present work the toxic activity of extracts of Eupatorium microphyllum L.F. was evaluated on 4th instar larvae of the mosquito Aedes aegypti (Linneaus), under laboratory conditions. Aqueous extracts were utilized in concentrations of 500 mg L-1, 1,500 mg L-1 and 2,500 mg L-1 and acetone in concentrations of 10 mg L-1, 20 mg L-1, 30 mg L-1, 40 mg L-1and 50 mg L-1. The bioassays were carried out for triplicate each one with 20 larvae, exposed for 24 hours to 150 mL of solution. In all the bioassays were employed control groups. In the evaluation of the acetone extracts, a negative control was employed to avoid that the mortality of the larvae to occur on account of the solvent. The Aqueous extracts showed low moderate action in the mortality of larvae, less than 20%. On the contrary, the action of the acetone extracts was observed to 10 and 20 mg L-1with 15% of mortality, while to 30 and 40 mg L-1 were registered 22 to 38% of mortality. However, to 50 mg L-1 the mortality was of 95.4% with highly significant statistical results. The concentrations of the acetone extracts showed to be the most efficient for the control of the mosquitoes selected. Both types of extracts showed toxic effect in larvae of A. aegypti, nevertheless, greater effect in the acetone extracts was observed relating to the aqueous extracts of E. microphyllum, which constitutes a viable alternative in the search of new larvicides from composed natural.

Análisis de las variables que inciden en la eficiencia de la gestión clínica en el área de consulta externa

La eficiencia en la gestión clínica de los médicos generales es un pilar fundamental en el control de los recursos en salud y puede generar un impacto positivo en la reducción de gastos innecesarios en el sistema. Se realiza un estudio analítico en donde se diseña una encuesta transversal para identificar las principales variables que puedan influir en la toma de decisiones de los médicos generales en una IPS de Bogotá, y se aplicó a 20 médicos. Los resultados encontrados fueron contrastados con la literatura actual. Se agruparon los resultados con variables como: relación profesional de la salud, organización y costo médico; pertinencia en la remisión a especialistas y formulación de medicamentos y paraclínicos, formación en pregrado de administración en salud, número de trabajos, cansancio físico, y finalmente, se analiza la influencia de la edad con otras variables descritas. Los resultados evidenciaron falta de conciencia por parte de los médicos con relación al control de los recursos que se relacionan con la mala derivación de los pacientes a los especialistas y la formulación de exámenes paraclínicos sin pertinencia adecuada. Sobre los factores descritos influyen características como la edad del médico, la adherencia a las guías de manejo, el cansancio físico y las características del paciente. Por otro lado hay una clara división con relación a la dirección y los médicos, no hay seguimiento a su desempeño, tampoco incentivos que promuevan la prestación del servicio con calidad, capacitación permanente, ni una remuneración adecuada. Finalmente, identificados dichos factores se plantean estrategias de intervención, y con esto generar un impacto adecuado en la optimización del recurso y mejoría de las condiciones laborales.

The effects of orthographic neighborhood in reading and laboratory word identification tasks : a review. 'Los efectos de vecindad ortográfica en lectura y en tareas de reconocimiento de palabras : una revisión'.

Resumen tomado de la revista

A means of assessing the wastage of efficiency in undergraduate education. 'Un método para evaluar las pérdidas de eficiencia en la educación de pregrado'.

Resumen tomado de la publicación