COST OF FRESH MARKET CELERY PRODUCTION IN SOUTHWESTERN MICHIGAN

This bulletin represents a tool that can help producers, consultants, educators, and agribusinesses working with producers estimate costs of production and expected profit based on "typical" celery management strategies found in southwestern Michigan. The budget included in this bulletin will allow users to revise inputs based on their management strategies and calculate their expected cost and profit. This flexibility provides a decision aid to search for systems that generate higher net returns to the farm's resource base.Crop Production/Industries,

COST OF CABBAGE PRODUCTION IN MONROE COUNTY, MICHIGAN

This bulletin represents a tool that can help producers, consultants, educators, and agribusinesses working with producers estimate costs of production and expected profit based on "typical" cabbage management strategies found in Monroe County, Michigan. The budget included in this bulletin will allow users to revise inputs based on their management strategies and calculate their expected cost and profit. This flexibility provides a decision aid to search for systems that generate higher net returns to the farm's resource base.Crop Production/Industries,

Efficient multiple time scale molecular dynamics: using colored noise thermostats to stabilize resonances

Multiple time scale molecular dynamics enhances computational efficiency by updating slow motions less frequently than fast motions. However, in practice the largest outer time step possible is limited not by the physical forces but by resonances between the fast and slow modes. In this paper we show that this problem can be alleviated by using a simple colored noise thermostatting scheme which selectively targets the high frequency modes in the system. For two sample problems, flexible water and solvated alanine dipeptide, we demonstrate that this allows the use of large outer time steps while still obtaining accurate sampling and minimizing the perturbation of the dynamics. Furthermore, this approach is shown to be comparable to constraining fast motions, thus providing an alternative to molecular dynamics with constraints.Comment: accepted for publication by the Journal of Chemical Physic

Tunneling and delocalization in hydrogen bonded systems: a study in position and momentum space

Novel experimental and computational studies have uncovered the proton momentum distribution in hydrogen bonded systems. In this work, we utilize recently developed open path integral Car-Parrinello molecular dynamics methodology in order to study the momentum distribution in phases of high pressure ice. Some of these phases exhibit symmetric hydrogen bonds and quantum tunneling. We find that the symmetric hydrogen bonded phase possesses a narrowed momentum distribution as compared with a covalently bonded phase, in agreement with recent experimental findings. The signatures of tunneling that we observe are a narrowed distribution in the low-to-intermediate momentum region, with a tail that extends to match the result of the covalently bonded state. The transition to tunneling behavior shows similarity to features observed in recent experiments performed on confined water. We corroborate our ice simulations with a study of a particle in a model one-dimensional double well potential that mimics some of the effects observed in bulk simulations. The temperature dependence of the momentum distribution in the one-dimensional model allows for the differentiation between ground state and mixed state tunneling effects.Comment: 14 pages, 13 figure

How Does Financial Globalization Affect Government Size?

More open economies have larger governments because the public sector functions as a compensatory mechanism against risks associated with trade and financial globalization.York's Knowledge Mobilization Unit provides services and funding for faculty, graduate students, and community organizations seeking to maximize the impact of academic research and expertise on public policy, social programming, and professional practice. It is supported by SSHRC and CIHR grants, and by the Office of the Vice-President Research & Innovation. [email protected] www.researchimpact.c

MEXICAN BIOGEOGRAPHIC PROVINCES: PRELIMINARY SCHEME, GENERAL CHARACTERIZATIONS, AND SYNONYMIES

Although the biogeographic schemes proposed for Mexico are based on different criteria (geographic, paleontological, faunistic or floristic), their authors implicitly acknowledge that the units recognized actually represent historical entities. The development of panbiogeography and cladistic biogeography has challenged traditional classifications, by showing that some of these biogeographic units did not represent natural units. Furthermore, there have been attempts to construct ecogeographic systems, based on the assumption that biotic and abiotic factors constraint species distributions within definite areas. By synthesizing both biogeographic and ecological systems, we propose a new scheme for Mexico, where we recognize the following 14 provinces: California (northern portion of the Baja California peninsula, from Sierras of San Pedro Mártir and Juárez, extending northward along the Sierra Nevada into southwestern USA), Baja California (Baja California peninsula), Sonora (coastal areas in northwestern Mexico, from the northeastern portion of the Baja California peninsula to the Piaxtla river basin in southern Sinaloa), Mexican Plateau (central Mexico, in the states of Zacatecas, San Luis Potosí, Guanajuato, Chihuahua, Coahuila, Durango, and Nuevo Mexico, as well as small parts of Nuevo León, and Sonora, below 4,000 m altitude), Tamaulipas (coastal areas in the northern part of the Mexican Gulf, north of the Pánuco river basin), Sierra Madre Occidental (western Mexico, in the states of Chihuahua, Durango, Zacatecas, Sonora, Sinaloa, Nayarit, and Jalisco, above 1,000 m altitude), Sierra Madre Oriental (eastern Mexico, in the states of San Luis Potosí, Tamaulipas, Coahuila, Hidalgo, Nuevo León, Veracruz, Puebla, and Querétaro, above 1,500 m altitude), Transmexican Volcanic Belt (central Mexico, in the states of Guanajuato, Mexico, Distrito Federal, Jalisco, Michoacán, Puebla, Oaxaca, Tlaxcala, and Veracruz), Balsas Basin (central Mexico, in the states of Guerrero, Mexico, Jalisco, Michoacán, Morelos, Oaxaca, and Puebla, below 2,000 m altitude), Sierra Madre del Sur (south central Mexico, from southern Michoacán to Guerrero and Oaxaca, and part of Puebla, above 1,000 m altitude), Mexican Gulf (coast of the Mexican Gulf, in eastern Mexico, Belize, and northern Guatemala), Mexican Pacific Coast (western Mexico, in the Pacific coast of the states of Sinaloa, Nayarit, Colima, Jalisco, Michoacán, Guerrero, Oaxaca, and Chiapas), Yucatán Peninsula (Yucatán peninsula, in the states of Campeche, Yucatán, and Quintana Roo, below 200 m altitude), and Chiapas (southern Mexico, Guatemala, and Nicaragua, basically corresponding to the Sierra Madre de Chiapas, from 500 to 2,000 m altitude).A pesar de que los esquemas biogeográficos propuestos para México se basan en diferentes criterios (geográficos, paleontológicos, faunísticos o florísticos), sus autores implícitamente asumen que las unidades reconocidas representan entidades históricas. El desarrollo de la panbiogeografía y la biogeografía cladística ha cuestionado estas clasificaciones tradicionales, al mostrar que algunas de estas unidades biogeográficas no representaban unidades naturales. Más aún, ha habido intentos para construir sistemas ecogeográficos, basados en el supuesto que los factores bióticos y abióticos constriñen las distribuciones de las especies dentro de áreas definidas. Aquí proponemos un nuevo esquema para México, al sintetizar ambos sistemas biogeográfico y ecológico, de acuerdo con el cual reconocemos las siguientes 14 provincias: California (porción norte de la península de Baja California, desde las Sierras de San Pedro Mártir y Juárez, extendiéndose hacia el norte a lo largo de la Sierra Nevada en el sudoeste de los Estados Unidos), Baja California (península de Baja California), Sonora(áreas costeras del noroeste de México, desde la porción noreste de la península de Baja California hasta la cuenca del río Piaxtla en el sur de Sinaloa), Altiplano Mexicano (centro de México, en los estados de Zacatecas, San Luis Potosí, Guanajuato, Chihuahua, Coahuila, Durango y Nuevo Mexico, así como pequeñas partes de Nuevo León y Sonora, debajo de los 4,000 m de altitud), Tamaulipas (áreas costeras en la parte norte del Golfo de México, al norte de la cuenca del río Pánuco), Sierra Madre Occidental (oeste de México, en los estados de Chihuahua, Durango, Zacatecas, Sonora, Sinaloa, Nayarit y Jalisco, por encima de los 1,000 m de altitud), Sierra Madre Oriental (este de México, en los estados de San Luis Potosí, Tamaulipas, Coahuila, Hidalgo, Nuevo León, Veracruz, Puebla y Querétaro, por encima de los 1,500 m de altitud), Eje Volcánico Transmexicano (centro de México, en los estados de Guanajuato, México, Distrito Federal, Jalisco, Michoacán, Puebla, Oaxaca, Tlaxcala y Veracruz), Depresión del Balsas (centro de México, en los estados de Guerrero, México, Jalisco, Michoacán, Morelos, Oaxaca y Puebla, por debajo de los 2,000 m de altitud), Sierra Madre del Sur (sur centro de México, desde el sur de Michoacán hasta Guerrero y Oaxaca, y parte de Puebla, por encima de los 1,000 m de altitud), Golfo de México (costa del Golfo de México, en el este de México, Belice y norte de Guatemala), Costa Pacífica Mexicana (oeste de México, en la costa Pacífica de los estados de Sinaloa, Nayarit, Colima, Jalisco, Michoacán, Guerrero, Oaxaca y Chiapas), Península de Yucatán (península de Yucatán, en los estados de Campeche, Yucatán y Quintana Roo, por debajo de los 200 m de altitud) y Chiapas (sur de México, Guatemala y Nicaragua, básicamente corresponde a la Sierra Madre de Chiapas, desde los 500 a los 2,000 m de altitud)

Spatiotemporal profile of peri-saccadic contrast sensitivity

Sensitivity to luminance contrast is reduced just before and during saccades (saccadic suppression), whereas sensitivity to color contrast is unimpaired peri-saccadically and enhanced post-saccadically. The exact spatiotemporal map of these perceptual effects is as yet unknown. Here, we measured detection thresholds for briefly flashed Gaussian blobs modulated in either luminance or chromatic contrast, displayed at a range of eccentricities. Sensitivity to luminance contrast was reduced peri-saccadically by a scaling factor, which was almost constant across retinal space. Saccadic suppression followed a similar time course across all tested eccentricities and was maximal shortly after the saccade onset. Sensitivity to chromatic contrast was enhanced post-saccadically at all tested locations. The enhancement was not specifically linked to the execution of saccades, as it was also observed following a displacement of retinal images comparable to that caused by a saccade. We conclude that luminance and chromatic contrast sensitivities are subject to distinct modulations at the time of saccades, resulting from independent neural processes