340 research outputs found
Meteorological-Based Predictions of Wheat Head Blight Epidemic in the Southern Argentinean Pampas Region
In Argentina, head blight is a highly risky disease (caused by Fusarium graminearum), although its occurrence is sporadic depending on prevalent environmental variables. These traits stimulated the development of predictive models of head blight occurrence which would help growers in the selection of control strategies. Empirical equations for predicting head blight incidence were developed at Pergamino (33° 56′ S, 60° 30′ W) associating temperature and moisture variables with mean disease data. Recently a new fundamental-empirical approach for estimating Fusarium index (incidence% x severity%/100) was developed using data of Pergamino and Marcos Juarez (32° 41′ S, 62°07′ W). In this study our objective was to validate both approaches at three more southern locations: La Dulce (38° 10′ S, 58° 00′ W), Miramar (38° 00′ S, 57° 33′ W) and Balcarce (37° 45′ S, 58° 18W), for the 2001 crop season. Examining partial and mean deviation values between observed and predicted incidence data, an underestimation especially at La Dulce was assessed. A clear improvement of incidence goodness of fit estimations was obtained decreasing the heat accumulation defining the length of the wheat critical period for infection. Employing this last critical period length for the fundamental-empirical approach led to satisfactory Fusarium index predictions. This study showed that both approaches developed at northern locations of the Pampas region can be portable and useful for predicting disease intensity at more southern locations, making only a few changes.Centro de Investigaciones en FitopatologÃ
Knockout of proton-neutron pairs from O with electromagnetic probes
After recent improvements to the Pavia model of two-nucleon knockout from
O with electromagnetic probes the calculated cross sections are compared
to experimental data from such reactions. Comparison with data from a
measurement of the O(e,epn) reaction show much better agreement
between experiment and theory than was previously observed. In a comparison
with recent data from a measurement of the O(,pn) reaction the
model over-predicts the measured cross section at low missing momentum.Comment: 6 pages, 5 figure
Muestras de granos de maÃz: análisis de micotoxinas
El mundo demanda granos sanos e inocuos, las regulaciones de los paÃses compradores impactan en los paÃses productores quienes desean satisfacer las crecientes demandas impuestas para asegurar la protección de la salud y los derechos de los consumidores. La presencia de micotoxinas ocasiona pérdidas, porque la contaminación comienza a campo, se presenta en cosecha y continua en el almacenamiento especialmente, cuando las buenas prácticas están ausentes.La importancia consiste en impulsar la vigilancia a nivel nacional y la implementación de monitoreos para determinar la incidencia de las diferentes micotoxinas en las partidas de maÃz. Es por ello, que se requiere de muestras, y determinar el tamaño de muestra, es una decisión importante en cualquier investigación. Se presenta el diseño del muestreo1 (determinación de tamaño de muestra y plan de muestreo) realizado en el monitoreo de las partidas comerciales de granos de maÃz para exportación. Las muestras de granos de maÃz fueron obtenidas al momento de arribo en las terminales portuarias de los camiones provenientes de zonas de la región pampeana Argentina. La presencia de Fumonisina B total (FBt: B1, B2 y B3) fue predominante en dichas muestras. Sin embargo, según el programa conjunto FAO/OMS y las normas alimentarias Comité del Codex (2014), los niveles máximos en granos de maÃz entero y sin elaborar establecidos para un lote indicaron que se considera aceptable, si este contiene menos de 5000 μg/g. Según los resultados de los niveles de concentración de FBt obtenidos en las muestras2, en general, estuvieron por debajo de estos lÃmites, excepto en zonas de Córdoba donde solo 4 muestras presentaron valores superiores al contenido máximo fijado por UE (CE Nº1126/7 y 1881/6). El muestreo presentado podrÃa servir de guÃa a futuros trabajos de investigación, asà como la influencia de otros factores tales como, las variables meteorológicas y sus interacciones
The Role of Percentage of Prostate-specific Antigen Reduction After Focal Therapy Using High-intensity Focused Ultrasound for Primary Localised Prostate Cancer. Results from a Large Multi-institutional Series
Focal therapy (FT) for prostate cancer (PCa) is emerging as a novel therapeutic approach for patients with low- to intermediate-risk disease, in order to provide acceptable oncological control, whilst avoiding the side effects of radical treatment. Evidence regarding the ideal follow-up strategy and the significance of prostate-specific antigen (PSA) kinetics after treatment is needed. In this study, we aimed to assess the value of the percentage of PSA reduction (%PSA reduction) after FT in predicting the likelihood of any additional treatment or any radical treatment. We retrospectively analysed a multicentre cohort of 703 men receiving FT for low- and intermediate-risk PCa. Overall, the rates of any additional treatment and any radical treatment were 30% and 13%, respectively. The median follow-up period was 41 mo. The median %PSA reduction after FT was 73%. At Cox multivariable analysis, %PSA reduction was an independent predictor of any additional treatment (hazard ratio [HR]: 0.96; p 90%, the probability of any additional treatment within 5 yr was 20%. Conversely, for %PSA reduction of <10%, the probability of receiving any additional treatment within 5 yr was roughly 70%. This study is the first to assess the role of %PSA reduction in the largest multicentre cohort of men receiving FT for PCa. Given the lack of standardised follow-up strategies in the FT field, the use of the %PSA reduction should be considered
Low-risk Prostate Cancer: Identification, Management, and Outcomes.
ContextThe incidence of low-risk prostate cancer (PCa) has increased as a consequence of prostate-specific antigen testing.ObjectiveIn this collaborative review article, we examine recent literature regarding low-risk PCa and the available prognostic and therapeutic options.Evidence acquisitionWe performed a literature review of the Medline, Embase, and Web of Science databases. The search strategy included the terms: prostate cancer, low risk, active surveillance, focal therapy, radical prostatectomy, watchful waiting, biomarker, magnetic resonance imaging, alone or in combination.Evidence synthesisProspective randomized trials have failed to show an impact of radical treatments on cancer-specific survival in low-risk PCa patients. Several series have reported the risk of adverse pathologic outcomes at radical prostatectomy. However, it is not clear if these patients are at higher risk of death from PCa. Long-term follow-up indicates the feasibility of active surveillance in low-risk PCa patients, although approximately 30% of men starting active surveillance undergo treatment within 5 yr. Considering focal therapies, robust data investigating its impact on long-term survival outcomes are still required and therefore should be considered experimental. Magnetic resonance imaging and tissue biomarkers may help to predict clinically significant PCa in men initially diagnosed with low-risk disease.ConclusionsThe incidence of low-risk PCa has increased in recent years. Only a small proportion of men with low-risk PCa progress to clinical symptoms, metastases, or death and prospective trials have not shown a benefit for immediate radical treatments. Tissue biomarkers, magnetic resonance imaging, and ongoing surveillance may help to identify those men with low-risk PCa who harbor more clinically significant disease.Patient summaryLow-risk prostate cancer is very common. Active surveillance has excellent long-term results, while randomized trials have failed to show a beneficial impact of immediate radical treatments on survival. Biomarkers and magnetic resonance imaging may help to identify which men may benefit from early treatment
Modelado computacional de datos epidemiológicos para predecir enfermedades de cultivos con base meteorológica
Para predecir el comportamiento de enfermedades de las plantas, mediante la construcción de modelos predictivos, se evaluó la severidad de manchas foliares, ocasionada por el hongo Altenaria tenuissima, en plantaciones de arándano alto (cultivar O’Neal) en tres localidades: San Pedro (S 33º 43' - W 059º 41'), Concordia (S 31º 24' - W 058º 02') y Gualeguaychú (S 33º 01' - W 058º 31'), durante los ciclos epidémicos primavero-estivo-otoñales de 2008/09 y 2009/10. Los mejores modelos simples de regresión logÃstica de respuesta binaria integraron a Snc y a DTxnP (dÃas con temperaturas entre 16 y 36°C), con precisiones de predicción de 93,8% y 78,5% respectivamente. El mejor modelo de respuesta ordinal integró a la interacción FPr*DTxnP (dÃas con precipitación*dÃas con temperaturas entre 16 y 36°C) y a Snc, con una precisión de predicción de 86,2%. La explicación biológica que subyace a los resultados obtenidos, refiere a un lento progreso epidémico primaveral, observado y simulado, contrastando con las altas tasas de incremento epidémico estivales, concordantes con hojas de senescencia creciente y alta frecuencia de dÃas con registros térmicos entre 16 y 36ºC. Un adecuado ajuste y validación de los modelos predictivos obtenidos en esta investigación, permitirá el desarrollo de verdaderos sistemas de pronóstico, para la correcta gestión de la enfermedad, tanto desde el punto de vista técnico, como económico y ambiental.Sociedad Argentina de Informática e Investigación Operativ
First measurements of the ^16O(e,e'pn)^14N reaction
This paper reports on the first measurement of the ^16O(e,e'pn)^14N reaction.
Data were measured in kinematics centred on a super-parallel geometry at energy
and momentum transfers of 215 MeV and 316 MeV/c. The experimental resolution
was sufficient to distinguish groups of states in the residual nucleus but not
good enough to separate individual states. The data show a strong dependence on
missing momentum and this dependence appears to be different for two groups of
states in the residual nucleus. Theoretical calculations of the reaction using
the Pavia code do not reproduce the shape or the magnitude of the data.Comment: 10 pages, 11 figures, 2 tables, Accepted for publication in EPJ
Project of an advanced ISOL facility for exotic beams at LNL
Abstract In the framework of the European program to define a second generation Radioactive Ion Beam facility, LNL are proposing the construction in the next five–seven years of a specialized national facility for RIB originated by fission fragments produced by secondary neutrons. It consists on a two-accelerator ISOL-type facility to provide intense neutron-rich radioactive ion beams of highest quality, in the range of masses between 80 and 160. The conceptual design is based on a high intensity 50 MeV (100 kW) proton linac as driver and on the availability of the heavy-ion accelerator ALPI as post accelerator. The estimated neutron yield is 2×1014 n/s at 0°, high enough to satisfy the demand for an advanced RIB facility. An intense R&D program on different items is actually in progress in collaboration with other Laboratories and University groups and is moving in a European context
Estimativa da biomassa da parte aérea em pastagem de Urochloa decumbens com o uso de um sensor proximal de refletância do dossel.
As gramÃneas forrageiras tropicais, como a Urochloa (syn. Brachiaria) decumbens, são as mais utilizadas na bovinocultura extensiva e intensiva do Brasil. A U. decumbens é altamente aclimatada, principalmente em área de Cerrado, sendo considerada boa alternativa para a cria, recria e engorda de bovinos
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