766 research outputs found
Revisión sistemática de Mesolecanium Cockerell de la región Neotropical (Hemiptera: Coccidae), con sinonimia y combinaciones nuevas
Redescriptions and illustrations of 14 neotropical species included in Mesolecanium Cockerell are given. Eight species: Mesolecanium baccharidis (Cockerell), Mesolecanium impar (Cockerell), Mesolecanium mayteni Hempel, Mesolecanium nocturnum (Cockerell and Parrott), Mesolecanium obscurum (Hempel), Mesolecanium obvius Granara de Willink, Mesolecanium perditum (Cockerell), and Mesolecanium planum Hempel, belong to this genus; a key to separate the species is given. Five species are transferred: Mesolecanium campomanesiae Hempel and Mesolecanium pseudosemen Cockerell are moved to Magnococcus Granara de Willink becoming Magnococcus campomanesiae (Hempel) new combination, and Magnococcus pseudosemen (Cockerell) new combination. Mesolecanium jaboticabae Hempel is moved to Parthenolecanium Šulc becoming Parthenolecanium jaboticabae (Hempel) new combination, Mesolecanium batatae Cockerell to Pulvinaria Targioni Tozzetti becoming Pulvinaria batatae (Cockerell) new combination, and Mesolecanium ferum Hempel to Toumeyella Cockerell becoming Toumeyella ferum (Hempel) new combination. Mesolecanium uvicola Hempel is a new synonym of Coccus longulus Cockerell. Lectotypes for Mesolecanium impar (Cockerell) and Mesolecanium planum Hempel are designated.Se redescriben e ilustran 14 especies neotropicales incluidas en Mesolecanium Cockerell (Hemiptera: Coccidae). Ocho especies: Mesolecanium baccharidis (Cockerell), Mesolecanium impar (Cockerell), Mesolecanium mayteni (Hempel), Mesolecanium nocturnum (Cockerell y Parrott), Mesolecanium obscurum Hempel, Mesolecanium obvius Granara de Willink, Mesolecanium perditum (Cockerell), Mesolecanium planum Hempel, pertenecen a este género, las cuales se incluyen en una clave para separar las mismas. Cinco especies son transferidas: Mesolecanium campomanesiae (Hempel) y Mesolecanium pseudosemen (Cockerell), se transfieren a Magnococcus Granara de Willink como Magnococcus campomanesiae (Hempel) comb. nov. Magnococcus pseudosemen (Cockerell) comb. nov. respectivamente; Mesolecanium jaboticabae (Hempel) se transfiere a Parthenolecanium Šulc, como Parthenolecanium jaboticabae (Hempel) comb. nov.; Mesolecanium batatae (Cockerell) a Pulvinaria Targioni Tozzetti como, Pulvinaria batatae (Cockerell) comb. nov. y Mesolecanium ferum Hempel a Toumeyella Cockerell como Toumeyella ferum (Hempel) comb. nov. Se sinonimisa a Mesolecanium uvicola Hempel con Coccus longulus (Douglas). Se designan los lectotipos de Mesolecanium impar (Cockerell) y Mesolecanium planum Hempel
An extension to GUM methodology: degrees-of-freedom calculations for correlated multidimensional estimates
The Guide to the Expression of Uncertainty in Measurement advocates the use
of an 'effective number of degrees of freedom' for the calculation of an
interval of measurement uncertainty. However, it does not describe how this
number is to be calculated when (i) the measurand is a vector quantity or (ii)
when the errors in the estimates of the quantities defining the measurand (the
'input quantities') are not incurred independently. An appropriate analysis for
a vector-valued measurand has been described (Metrologia 39 (2002) 361-9), and
a method for a one-dimensional measurand with dependent errors has also been
given (Metrologia 44 (2007) 340-9). This paper builds on those analyses to
present a method for the situation where the problem is multidimensional and
involves correlated errors. The result is an explicit general procedure that
reduces to simpler procedures where appropriate. The example studied is from
the field of radio-frequency metrology, where measured quantities are often
complex-valued and can be regarded as vectors of two elements.Comment: 30 pages with 2 embedded figure
Preference and performance of Phyllocnistis citrella Stainton (Lepidoptera:Gracillariidae) on three citrus hosts: Laboratory and field assessment
The relationship between preference and performance is crucial to the ecology and evolution of plant-insect interactions. Oviposition preference and offspring performance were evaluated for a citrus pest, the leafminer Phyllocnistis citrella (Lepidoptera: Gracillariidae), on three of its host plants: lemon (Citrus limon L. Burm.), orange (Citrus sinensis L. Osbeck), and grapefruit (Citrus paradisi Macfadyen) in Tucumán province (northwest Argentina). Choice and no-choice tests were performed in open and enclosed environments, and performance parameters (development time, survival, pupal size, and sex ratio) were estimated from laboratory rearing and 3-yr field sampling data. Parasitism rates were studied in laboratory choice test and field assessments. Preference trends were inconsistent, with lemon receiving more eggs in some tests, whereas no preference was observed in others. Patterns of host use in the field did not show significant differences among species. Leafminer performance, including parasitism and predation rates, was generally homogeneous among host plants. From these results, lemon, orange, and grapefruit seem to represent intrinsically similar resources for P. citrella populations in northwest Argentina, a trend that was accompanied by a lack of consistent oviposition preferences in foraging females. Ecological conditions might be more important than physiological adaptation in shaping a probably labile host ranking in this pest species.La relación entre preferencia y rendimiento es crucial para la ecología y evolución de las interacciones insecto-planta. Se evaluó la preferencia de puesta y el rendimiento de la descendencia para una plaga de cítricos, el minador de la hoja Phyllocnistis citrella (Lepidoptera: Gracillariidae), sobre tres de sus plantas hospederas: limonero (Citrus limon [Linn.] Burm.), naranjo (Citrus sinensis [Linn.] Osbeck) y pomelo (Citrus paradisi Macfadyen) en la provincia de Tucumán (Noroeste de Argentina). Se realizaron pruebas con y sin elección en ambientes abiertos y cerrados, y se estimaron parámetros de rendimiento (tiempo de desarrollo, supervivencia, tamaño pupal y proporción de sexos) a partir de individuos criados en laboratorio y datos de tres años de muestreos de campo. Las tasas de parasitismo se estudiaron en pruebas de laboratorio con elección y evaluaciones en campo. Las tendencias de preferencia fueron inconsistentes, con limonero recibiendo más huevos en algunas pruebas, mientras que no se observó preferencia en otras. Los patrones de uso de hospedero en campo no mostraron diferencias significativas entre especies. El rendimiento del minador, incluyendo las tasas de parasitismo y depredación, fue generalmente homogéneo entre plantas hospederas. Con estos resultados, las plantas de limonero, naranjo y pomelo representarían intrínsecamente recursos similares para las poblaciones del minador de los cítricos en el NO de Argentina, tendencia que fue acompañada por la ausencia de preferencias consistentes en la puesta de huevos por parte de las hembras. Las condiciones ecológicas podrían ser más importantes que la adaptación fisiológica al moldear un rango de hospederos probablemente voluble en esta especie plaga.Fil: Goane, Lucía. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Valladares, Graciela Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Willink, Eduardo. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentin
Letter from Anton and Liek Tjeenk Willink to Sandra Eben, February 9, 1991
Letter from relatives of Sandra Eben in the Netherlands describing research related to the ancestors of the LeCocq family, of which Sandra is a descendant.https://nwcommons.nwciowa.edu/lecocqhistory/1003/thumbnail.jp
Spatio-temporal precipitation patterns: from teleconnections to improved long-term forecasts
The standardized precipitation index (SPI) is an important yet easy-to-calculate
means to describe wet or dry conditions in very different climates. In this work, a new
scheme for obtaining improved forecasts of this index is developed. The methodology
is tested over Russia and West Africa, proving that it can be successfully applied to
different forecasting models and world regions. For testing, we use two forecasting
models: the semi-implicit semi-Lagrangian vorticity-divergence (SL–AV) model of
the Hydrometeorological Centre of Russia and the Institute of Numerical Mathematics
of the Russian Academy of Sciences for Russia and the Climate Forecast System Version
2 (CFSv2) of the National Center for Environmental Prediction (NCEP) for West
Africa. Based on hindcast simulations of both models, we demonstrate relatively poor
skills in obtaining direct zero to three month lead-time SPI forecasts in the regions
of interest during summer season. In order to improve the accuracy of these forecasts,
we utilize surface temperature, mean sea level pressure and 500 hPa geopotential
height fields, obtained from the outputs of both models. The spatial patterns of crosscorrelations
between previously obtained climatological fields and our target variable
(SPI-1) are studied to identify informative co-variates, potentially affecting monthly scale precipitation variability. The cross-correlation structures between the different
fields reveal relevant interdependencies between SPI-1, sea surface temperature, mean sea level pressure and 500 hPa geopotential height in different regions. Subsequently, we employ two different regression models based on statistical post-processing of regional climate model output. In the first model, we consider all combinations of pairs of the previously identified predictors in a set of linear regression equations, which generates an ensemble of individual SPI-1 forecasts. The second model is based on a multiple linear regression approach comprising the dependency between all predictor variables and the predictand (SPI-1) in a single equation. The resulting SPI-1 forecasts obtained from both regression models are subsequently analysed in both deterministic and probabilistic ways and checked by various verification metrics. We identify that the first proposed model provides a significant improvement in the SPI forecasting, pointing to the potential for its implementation in operational monthly precipitation forecasts
Letter from Anton and Liek Tjeenk Willink to Sandra Eben, March 23, 1991
Letter from relatives in the Netherlands with additional research about the LeCocq ancestors. Includes photocopies of marriage certificate of Nicolaus LeCocq and birth certificate of his son Johannes LeCocq.https://nwcommons.nwciowa.edu/lecocqhistory/1004/thumbnail.jp
Aligning OCL with UML
OCL is widely used by UML and other languages to constrain meta-models and perform evaluations on models.
Unfortunately no OCL 2.x specification has ever been aligned with any UML 2.x specification. This lack of alignment makes some OCL compliance points such as XMI interchange unachievable. This paper describes how introduction of an OCL Pivot Meta-Model and clear exposition of the Values package may provide a solution to the alignment and a variety of other specification issues
Model Instantiation and Type Checking in UMLX
OMG's MDA initiative encourages the use of meta-model based transformations and re-usable specifications. We discuss how Graphical Transformation Notations such as UMLX reduce opportunities for errors in this programming domain
Modeling the OCL Standard Library
OCL is widely used by UML and other languages to constrain meta-models and perform evaluations on models. The OCL specification is the result of diligent but time-constrained human endeavor and so contains many inconsistencies, most of which are relatively easy to ignore as obvious typographical mistakes. However the need to ignore minor discrepancies undermines rigorous treatment of more significant issues. The minor issues can be substantially eliminated by auto-generating the specification. This paper provides early community visibility of proposed solutions to a variety of issues that arose while developing a model for the OCL Standard Library that forms the core of the OCL specification
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