Commercial Citrus or a Really Big Backyard: Small Citrus Growers and their Effects on Citrus Pest Populations

Crop Production/Industries,

Socioeconomic Factors and Water Quality in California

We investigate the relationships between water quality and socioeconomic factors in California at the county level for the years 1993 to 2006 using 24 water quality indicators coming from seven different types of water bodies. We estimate these relationships using three classes of models: the traditional per capita income-pollution level - Environmental Kuznets Curve (EKC) - specifications, a more inclusive model containing main socioeconomic variables such as agricultural intensity, land use, ethnic composition, population density and educational attainment, and a model that includes the socioeconomic variables while accounting for spatial correlations too. For most water quality indicators, we do not find support for EKC specifications. For pollutants like phosphorus and total suspended solids, the level of agricultural activity is a significant determinant of water quality in California, but for other surface water pollutants commonly considered agricultural pollutants, such as ammonia and nitrate, the level of agricultural activity is not statistically significant. We find that education, ethnic composition, age structure, land use, population density, and water area are all significantly correlated with various indicators of water quality.Water Quality Indicators, Socioeconomic Variables, EKC, Agriculture, Industry

Selective vs. Broad-Spectrum Pesticides: When Do Private Decisions Differ from Socially Optimal Decisions?

This paper examines the spatial externalities of conventional and organic pest control methods to determine if, and how, the two types affect each other. These interactions make the problem more complicated than the usual analysis of a single externality. The numerical simulation model includes one organically managed and one conventionally managed field. One pest and one predator of the pest move between the two fields over five seasons. In each season, the conventional grower has the option of applying a broad-spectrum pesticide that kills the predator a selective pesticide that has no adverse effects on the predator but is either more expensive or less effective than the broad-spectrum pesticide. The organic grower can apply an organic pesticide, augment the predator population, or both. The simulation model identifies the socially optimal pest control decisions and the Nash equilibrium decisions of both growers over the five growing seasons. The relative price and efficacy of the selective pesticide, the type of predator, and the type of pest introduction all influence whether or not either or both growers make inefficient decisions. Under certain conditions, regional pest management, equivalent to coordination of pest control across growers, could increase total regional profits.spatial-dynamic games, spatial externalities, non-cooperative games, organic agriculture, biological control, agricultural policy, Agricultural and Food Policy, Crop Production/Industries, Resource /Energy Economics and Policy, C61, C72, Q18, Q52, Q57,

Family and parenting characteristics associated with marijuana use by Chilean adolescents

OBJECTIVE: Family involvement and several characteristics of parenting have been suggested to be protective factors for adolescent substance use. Some parenting behaviors may have stronger relationships with adolescent behavior while others may have associations with undesirable behavior among youth. Although it is generally acknowledged that families play an important role in the lives of Chilean adolescents, scant research exists on how different family and parenting factors may be associated with marijuana use and related problems in this population which has one of the highest rates of drug use in Latin America. METHODS: Using logistic regression and negative binomial regression, we examined whether a large number of family and parenting variables were associated with the possibility of Chilean adolescents ever using marijuana, and with marijuana-related problems. Analyses controlled for a number of demographic and peer-related variables. RESULTS: Controlling for other parenting and family variables, adolescent reports of parental marijuana use showed a significant and positive association with adolescent marijuana use. The multivariate models also revealed that harsh parenting by fathers was the only family variable associated with the number of marijuana-related problems youth experienced. CONCLUSION: Of all the family and parenting variables studied, perceptions of parental use of marijuana and harsh parenting by fathers were predictors for marijuana use, and the experience of marijuana-related problems. Prevention interventions need to continue emphasizing the critical socializing role that parental behavior plays in their children's development and potential use of marijuana.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3109755/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3109755/Accepted manuscrip

A note on the comparison of three near infrared reflectance spectroscopy calibration strategies for assessing herbage quality of ryegrass

peer-reviewedPerennial ryegrass (n = 1,836), Italian ryegrass (n = 137) and hybrid ryegrass (n = 103) herbage was taken from harvested plots from the Irish national variety evaluation scheme and analysed for in vitro dry matter digestibility, water soluble carbohydrate concentration, crude protein concentration and buffering capacity. Spectral data were obtained using near infrared reflectance spectroscopy and three calibration strategies (global, species-specific or local) were utilised to relate the reference values to the spectral data. The local strategy generally provided the poorest estimation of herbage composition, with global and species-specific calibration strategies producing similarly accurate estimates of each quality trait. The higher accuracy and easier maintenance of the global strategy make it the recommended calibration method for analysing quality of ryegrass.Department of Agriculture, Food and the Marine Research Stimulus Fund (07 526

Jimmy Carter’s Human Rights Diplomacy and the Democratization of Taiwan

President Carter began a new era of American diplomacy by attempting to refocus America\u27s foreign policy towards promoting human rights. Taiwan provides an interesting case study to see the effectiveness of Carter\u27s human rights policy and the difficulty in applying it to nations that were of critical importance during the Cold War. In particular, this thesis analyzes the relationship between arms sales to Taiwan, human rights, and the process of normalization with the People\u27s Republic of China, as well as the integration of human rights into foreign policy decision making. This paper also examines the impact of American embassy initiatives on human rights and the process of democratization in Taiwan

Comparison of herbage yield, nutritive value and ensilability traits of three ryegrass species evaluated for the Irish Recommended List

peer-reviewedThis study examined 169 of the newest varieties of three ryegrass species, perennial (Lolium perenne L.), Italian (Lolium multiflorum Lam.) and hybrid (Lolium boucheanum Kunth), from Recommended List trials in Ireland. The traits examined were yield, dry matter concentration, three nutritive value traits (in vitro dry matter digestibility, water-soluble carbohydrate on a dry matter basis and crude protein concentration) and two ensilability traits (buffering capacity and water soluble carbohydrate concentration on an aqueous phase basis). Varietal monocultures of each species underwent a six cut combined simulated grazing and silage management in each of two years following sowing. Perennial ryegrass yielded less than both other species in one-year-old swards, but less than only Italian ryegrass in two-year-old swards, but generally had the higher in vitro dry matter digestibility and crude protein values. Italian ryegrass displayed the most favourable ensilability characteristics of the three species with perennial ryegrass less favourable and hybrid ryegrass intermediate. Overall, despite the high yields and favourable nutritive value and ensilability traits recorded, the general differences between the three ryegrass species studied were in line with industry expectations. These findings justify assessing the nutritive value and ensilability of ryegrass species, in addition to yield, to allow farmers select species that match farming enterprise requirements.We acknowledge the Department of Agriculture, Food and the Marine for funding provided through the Research Stimulus Fund (07 526

The Externalities of Conventional and Organic Pest Management: When Do Gains to Cooperation Exist?

During the 1990s, demand for organic products increased on average by 20% each year. This growth in demand fueled growth in organic crop acreage. Between 1992 and 2005, organic cropland more than quadrupled, going from 403,400 acres to just over 1.7 million acres (USDA, 2008). Demand is predicted to increase annually by an additional 9 to 16% through 2010 (Dimitri and Oberholtzer, 2005). This further increase in demand will lead to an additional expansion of organic acreage, increasing the heterogeneity of agricultural regions and increasing the interaction that occurs between conventional and organic farms as they more frequently share the same regional landscape. Sharing the same landscape implies that they share pest and natural enemy populations. The movement of these organisms links farms within a region, potentially causing one grower’s pest control decisions to impact other growers. This paper examines these interactions. The analysis focuses on one organic and one conventional profit-maximizing grower. One pest and one natural enemy population connect the time periods in the model, and the movement of these populations connects the grower’s fields, creating a spatial-dynamic model. The analysis compares the privately optimal levels of pest control on the neighboring farms with the socially optimal levels of pest control. This comparison will illuminate situations when private decisions lower the region’s total profits via negative externalities created by the movement of insects. The model examines how these externalities differ under different population dynamics.Crop Production/Industries,

The association of at-risk, problem, and pathological gambling with substance use, depression, and arrest history

We examined at-risk, problem, or pathological gambling co-occurrence with frequency of past-year alcohol, tobacco, and marijuana use; depressive symptoms; and arrest history. Data included the responses of over 3,000 individuals who participated in a 2006 telephone survey designed to understand the extent of at-risk, problem, and pathological gambling; comorbidity levels with substance use; mental health; and social problems among Southwestern U.S. residents. Data were analyzed with multinomial and bivariate logistic regression. Respondents at risk for problem gambling were more likely to use alcohol, tobacco, and marijuana than those respondents not at risk. Pathological gamblers were no more or less likely to consume alcohol or tobacco than were non-gamblers or those not at risk. A dose-response relationship existed between degree of gambling problems and depressive symptoms and arrest history. Interventions for at-risk or problem gamblers need to include substance use treatment, and the phenomenon of low levels of substance use among pathological gamblers needs further exploration