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,

The Fish Kill Mechanism of the Harmful Raphidophyte Chattonella Subsalsa

Harmful algae blooms (HABs) and toxins associated with HAB species are a significant threat to the health of marine species and coastal environments. In the South Carolina coastal zone, HABs have proliferated with intensified anthropogenic eutrophication in coastal waters. The raphidophyte species Chattonella subsalsa is a prominent cause of algal blooms resulting in fish kills in South Carolina. Though C. subsalsa is a known ichthyotoxic alga, the fish kill mechanism of this species remains unidentified. C. subsalsa is likely to elicit fish mortality via one of two mechanisms: (1) gill damage induced by cell contact irritation or (2) the production of a bioactive compound or toxin. We hypothesized physical damage and subsequent mortality was caused by direct contact with C. subsalsa cells and that the lethality of C. subsalsa is related to the algal growth phase, with the maximum harmful effect occurring during the exponential growth phase. Larvae of Fundulus heteroclitus were exposed to cultures of C. subsalsa at various phases of growth both directly and indirectly (through a 0.2 μm mesh) for 48 hours. Fish mortality and gill tissue damage were used to measure the effects of C. subsalsa exposures. The greatest mortalities and gill damage were observed via indirect exposure to C. subsalsa cultures in the exponential growth phase. These results suggest C. subsalsa produces a bioactive compound that induces gill damage and subsequent mortalities without the necessity of contact with algal cells and that C. subsalsa is most lethal during the exponential growth phase

Parents\u27 Choice of Pre-Kindergarten: A Transactional Ecological Approach

Empirical research on parents’ decision making process and parents’ actual criteria when considering preschool is critical when considering its relationship to early educational experiences and subsequent outcomes for children. Research has consistently demonstrated that the type and quality of preschool program children attend has implications for future academic success. A review of past research suggests parents often have difficulty assessing quality and include a wide range of considerations that include both practical and educational features of care. The current study utilized a transactional ecological framework to examine parent considerations and related family, child and cultural factors. A series of focus groups and interviews were conducted with parents to identify parent considerations and inform creation of a survey measure designed to assess these considerations. Surveys were then completed by 203 parents from varying socioeconomic and ethnic backgrounds who had a child that qualified for state-funded preschool the following year. Parents were recruited from 20 centers including Head Start programs, private-for profit programs, religiously affiliated programs and one YMCA center. Exploratory factor analysis identified two highly correlated categories of considerations: 1) characteristics that designate several types of quality indicators and 2) characteristics that designate a program’s practical features. A series of hierarchical regressions indicated a combination of cultural, family and child factors are important when assessing parents’ considerations for pre-kindergarten. In particular, socioeconomic status, parents’ beliefs about childrearing and involvement and children’s prosocial skills and family structure were uniquely related to parental endorsement of quality and practical considerations. These findings have important implications for policymakers and practitioners

New records of biting and predaceous midges from Florida, including species new to the fauna of the United States (Diptera: Ceratopogonidae)

We provide new records of biting and predaceous midges (Diptera: Ceratopogonidae) from Florida, including the first documented United States records of Atrichopogon (Atrichopogon) caribbeanus Ewen, Dasyhelea griseola Wirth, D. scissurae Macfie, and Brachypogon (Brachypogon) woodruffi Spinelli and Grogan. Atrichopogon (Meloehelea) downesi Wirth, Forcipomyia (Thyridomyia) monilicornis (Coquillett), F. (T.) nodosa Saunders, Ceratoculicoides blantoni Wirth and Ratanaworabhan, Mallochohelea albibasis (Malloch), Bezzia (Bezzia) imbifida Dow and Turner and B. (B.) mallochi Wirth are recorded for the first time from Florida. Forcipomyia (Thyridomyia) johannseni Thomsen, Bezzia (Bezzia) expolita (Coquillett), and B. (B.) pulverea (Coquillett) are deleted from the ceratopogonid fauna of Florida. Dasyhelea koenigi Delécolle and Rieb is a junior objective synonym of Dasyhelea scissurae Macfie (NEW SYNONYM). The total number of Ceratopogonidae recorded from Florida is now 249 species contained within 27 genera

The use and re-use of unsustainable groundwater for irrigation: A global budget

Depletion of groundwater aquifers across the globe has become a significant concern, as groundwater is an important and often unsustainable source of irrigation water. Simultaneously, the field of water resource management has seen a lively debate over the concepts and metrics used to assess the downstream re-use of agricultural runoff, with most studies focusing on surface water balances. Here, we bring these two lines of research together, recognizing that depletion of aquifers leads to large amounts of groundwater entering surface water storages and flows by way of agricultural runoff. While it is clear that groundwater users will be impacted by reductions in groundwater availability, there is a major gap in our understanding of potential impacts downstream of groundwater pumping locations. We find that the volume of unsustainable groundwater that is re-used for irrigation following runoff from agricultural systems is nearly as large as the volume initially extracted from reservoirs for irrigation. Basins in which the volume of irrigation water re-used is equal to or greater than the volume of water initially used (which is possible due to multiple re-use of the same water) contain 33 million hectares of irrigated land and are home to 1.3 billion people. Some studies have called for increasing irrigation efficiency as a solution to water shortages. We find that with 100% irrigation efficiency, global demand for unsustainable groundwater is reduced by 52%, but not eliminated. In many basins, increased irrigation efficiency leads to significantly decreased river low flows; increasing irrigation efficiency to 70% globally decreases total surface water supplies by backsim600 km3 yr−1. These findings illustrate that estimates of aquifer depletion alone underestimate the importance of unsustainable groundwater to sustaining surface water systems and irrigated agriculture

A qualitative exploration of whether lesbian and bisexual women are 'protected' from sociocultural pressure to be thin

Heterosexual women in Western cultures are known to experience body image concerns, dieting and disordered eating as a result of intense social pressures to be thin. However, it is theorised that lesbian and bisexual women belong to a subculture that is ‘protective’ of such demands. Fifteen non-heterosexual women were interviewed about their experiences of social pressure. Thematic analysis of their accounts suggests that such theorising may be inaccurate, because these lesbian and bisexual women did not feel ‘protected’ from social pressures and experienced body dissatisfaction. While they might attempt to resist thin idealisation, resistance is not centred around their sexuality

Adaptability of Irrigation to a Changing Monsoon in India: How far can we go?

Agriculture and the monsoon are inextricably linked in India. A large part of the steady rise in agricultural production since the onset of the Green Revolution in the 1960’s has been attributed to irrigation. Irrigation is used to supplement and buffer crops against precipitation shocks, but water availability for such use is itself sensitive to the erratic, seasonal and spatially heterogeneous nature of the monsoon. Most attention in the literature is given to crop yields (Guiteras, 2009; Fishman, 2012; Auffhammer et al, 2011) and their ability to withstand precipitation shocks, in the presence of irrigation (Fishman, 2012). However, there remains limited evidence about how natural weather variability and realized irrigation outcomes are related. We provide new evidence on the relationship between monsoon changes, irrigation variability and water availability by linking a process based hydrology model with an econometric model for one of the world’s most water stressed countries. India uses more groundwater for irrigation than any other country, and there is substantial evidence that this has led to depletion of groundwater aquifers. First, we build an econometric model of historical irrigation decisions using detailed crop-wise agriculture and weather data spanning 35 years from 1970-2004 for 311 districts across 19 major agricultural states in India. The source of agricultural data comes from the Village Dynamics in South Asia database at the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT). Weather data is sourced from the only long term continental scale daily observationally gridded precipitation and temperature dataset called APHRODITE (Asian Precipitation- Highly Resolved Observational Data Integration Towards Evaluation of the Water Resources), that captures the spatial extent of the monsoon across the Himalayas, South and South-East Asia, and the Middle East in great detail. We use panel data approaches to control for unobserved and omitted variables that can confound the true impacts of weather variability on irrigation. Exploiting the exogenous inter-annual variability in the monsoon, our multivariate regression models reveal that for crops grown in the wet season, irrigation is sensitive to distribution and total monsoon rainfall but not to ground or surface water availability. For crops grown in the dry season, total monsoon rainfall matters most, and its effect is sensitive to groundwater availability but differentially so for shallow dug wells and deep tube wells. The historical estimates from the econometric model are used to calculate future irrigated areas using three different bias-corrected climate model projections of monsoon climate for the years 2010 – 2050 under the strongest warming scenario ( business as usual scenario) RCP-8.5 from the CMIP5 (Coupled Model Intercomparison Project) models. These projections are then used as input to a physical hydrology model, such as the Water Balance Model, that tracks water use and exchange between the ground, atmosphere, runoff and stream networks. This enables us to quantify supply of water required to meet irrigation needs from sustainable sources such as rechargeable shallow groundwater, rivers and reservoirs, as well as unsustainable sources such as non- rechargeable groundwater. Preliminary results show that the significant variation in monsoon projections lead to very different results. Crops grown in the dry season show particularly divergent trends between model projections, leading to very different groundwater resource requirements. By combining the strengths of the economic and hydrology components, this work highlights potential sustainable or unsustainable water use trajectories that different regions within India will face

Abnormal infant islet morphology precedes insulin resistance in PCOS-like monkeys.

Polycystic ovary syndrome (PCOS) is prevalent in reproductive-aged women and confounded by metabolic morbidities, including insulin resistance and type 2 diabetes. Although the etiology of PCOS is undefined, contribution of prenatal androgen (PA) exposure has been proposed in a rhesus monkey model as premenopausal PA female adults have PCOS-like phenotypes in addition to insulin resistance and decreased glucose tolerance. PA female infants exhibit relative hyperinsulinemia, suggesting prenatal sequelae of androgen excess on glucose metabolism and an antecedent to future metabolic disease. We assessed consequences of PA exposure on pancreatic islet morphology to identify evidence of programming on islet development. Islet counts and size were quantified and correlated with data from intravenous glucose tolerance tests (ivGTT) obtained from dams and their offspring. Average islet size was decreased in PA female infants along with corresponding increases in islet number, while islet fractional area was preserved. Infants also demonstrated an increase in both the proliferation marker Ki67 within islets and the beta to alpha cell ratio suggestive of enhanced beta cell expansion. PA adult females have reduced proportion of small islets without changes in proliferative or apoptotic markers, or in beta to alpha cell ratios. Together, these data suggest in utero androgen excess combined with mild maternal glucose intolerance alter infant and adult islet morphology, implicating deviant islet development. Marked infant, but subtle adult, morphological differences provide evidence of islet post-natal plasticity in adapting to changing physiologic demands: from insulin sensitivity and relative hypersecretion to insulin resistance and diminished insulin response to glucose in the mature PCOS-like phenotype

Assessing Criterion Validity of Using Internet Searches as a Measure of Public Attention

We examine the criterion validity of using internet searches as a measure of public attention to United States Supreme Court (USSC) cases. First, we construct a measure of public attention to three cases by comparing relevant search terms in Google Trends to one top search terms of the year, then sum the measure week by week during the period of the research design. To test the measure’s criterion validity, we replicate Scott and Saunders’ (2006) models using their dataset (created by conducting phone interviews of a national sample using random digit dialing) that was designed to assess awareness of USSC decisions. We fnd that public attention as measured by Google Trends data is predictive of public awareness of USSC decisions for two of their three models. We conclude that using free, publicly available big data to measure public attention to USSC cases has criterion validity, and is a valuable tool for researchers studying public policy and process. Our fndings contribute to the body of research by demonstrating the validity of internet searches as a measure of public attention beyond its validity in elections and public policy, as Swearingen and Ripberger (2014) and Ripberger (2011) have done

Student Engagement in After-School Programs, Academic Skills, and Social Competence among Elementary School Students

Research on the relationship between after-school program participation and student outcomes has been mixed, and beneficial effects have been small. Most recent studies suggest that participation is best characterized as a multidimensional concept that includes enrollment, attendance, and engagement, which help explain differences in student outcomes. The present study uses data from a longitudinal study of after-school programs in elementary schools to examine staff ratings of student engagement and school outcomes. The factor structure of the staff-rated measure of student engagement was examined by exploratory factor analysis. Multiple regression analyses found that student engagement in academic, youth development, and arts after-school program activities was significantly related to changes in teacher ratings of academic skills and social competence over the course of the school year and that students with the greatest increase in academic skills both were highly engaged in activities and attended the after-school program regularly. The results of this study provide additional evidence regarding the benefits of after-school programs and the importance of student engagement when assessing student outcomes