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Knowledge creation is a social enterprise, especially in political science. Sharing new findings widely and quickly is essential for progress. Scholars can now use Twitter to rapidly disseminate ideas, and many do. What are the implications of this new tool? Who uses it, how do they use it, and what are the implications for exacerbating or ameliorating existing inequalities in terms of research dissemination and attention? We construct a novel dataset of all 1,236 political science professors at PhD-granting institutions in the United States who have a Twitter account to answer these questions. We find that female scholars and those on the tenure track are more likely to use Twitter, especially for the dissemination of research. However, we consistently find that research by men shared on Twitter is more likely to be passed along further by men than research by women.
A sizeable proportion of households is forced to share single long-lasting insecticide treated net (LLIN). However, the relationship between increasing numbers of people sharing a net and the risk for Plasmodium infection is unclear. This study revealed whether risk for Plasmodium falciparum infection is associated with the number of people sharing a LLIN in a holoendemic area of Kenya. Children ⩽5 years of age were tested for P. falciparum infection using polymerase chain reaction. Of 558 children surveyed, 293 (52.5%) tested positive for parasitaemia. Four hundred and fifty-eight (82.1%) reported sleeping under a LLIN. Of those, the number of people sharing a net with the sampled child ranged from 1 to 5 (median = 2). Children using a net alone or with one other person were at lower risk than non-users (OR = 0.29, 95% CI 0.10–0.82 and OR = 0.47, 95% CI 0.22–0.97, respectively). On the other hand, there was no significant difference between non-users and children sharing a net with two (OR = 0.88, 95% CI 0.44–1.77) or more other persons (OR = 0.75, 95% CI 0.32–1.72). LLINs are effective in protecting against Plasmodium infection in children when used alone or with one other person compared with not using them. Public health professionals should inform caretakers of the risks of too many people sharing a net.
To answer questions about the origins and outcomes of collective action, political scientists increasingly turn to datasets with social network information culled from online sources. However, a fundamental question of external validity remains untested: are the relationships measured between a person and her online peers informative of the kind of offline, “real-world” relationships to which network theories typically speak? This article offers the first direct comparison of the nature and consequences of online and offline social ties, using data collected via a novel network elicitation technique in an experimental setting. We document strong, robust similarity between online and offline relationships. This parity is not driven by shared identity of online and offline ties, but a shared nature of relationships in both domains. Our results affirm that online social tie data offer great promise for testing long-standing theories in the social sciences about the role of social networks.
Little research exists on the optimal temporal frequency between soil tests, given empirical data on potassium (K) carryover and its interaction with cotton yield. We evaluate how decreasing the temporal frequency between obtaining K soil test information affects the net present value (NPV) of cotton production. Monte Carlo simulation was used to determine NPV for cotton production using five soil test schedules ranging from soil testing annually to every fifth year. NPV of returns to K was maximized at $7,580/ac. when producers updated soil testing information every 2 years, which was $2/ac. per year greater than annual soil testing.
We determined the profitability and risk for spring- and fall-calving beef cows in Tennessee. Simulation models were developed using 19 years of data and considered the seasonality of cattle prices and feed prices for least-cost feed rations to find a distribution of net returns for spring- and fall-calving seasons for two weaning months. Fall calving was more profitable than the spring calving for all feed rations and weaning months. Fall calving was also risk preferred over spring calving for all levels of risk aversion. Higher calf prices at weaning were the primary factor influencing the risk efficiency of fall calving.
The objective of this research was to describe proportional differences across time and region in management practices among southern cotton farmers who experienced glyphosate-resistant (GR) weeds on their farms earlier than those who experienced them later and among farmers who were closest to one of four historical outbreak epicenters: Lauderdale County, TN; Macon County, GA; Edgecombe County, NC; and Terry County, TX. A mail survey was conducted with cotton farmers in 2012 from 13 southern, cotton-producing states. Survey responses on practices used by farmers were classified into three broad categories of labor, mechanical/tillage/chemical (MTC), and cultural. Proportions of respondents using practices from each category were identified by time and region; across which, proportional-difference tests were conducted. Results indicated respondents encountering GR weeds earlier were more likely than farmers who experienced them later to use the three broad-category practices (labor, 98 vs. 92%; MTC, 95 vs. 89%; and cultural, 86 vs. 76%) and specific practices, including hooded sprayers (76 vs. 58%), in-season herbicide change (83 vs. 60%), and field-border management (60 vs. 35%). Also, respondents closest to Lauderdale County were more likely than farmers closest to Edgecombe County to use broad-labor practices (99 vs. 91%) and specific practices, including hand hoeing (96 vs. 84%), hand spraying (49 vs. 31%), spot spraying (76 vs. 59%), wick applicator (13 vs. 11%), and field-border management (58 vs. 39%). Education programs on weed management can be developed and tailored according to the time and regional differences to provide effective information and communication channels to farmers.
Children who sleep on the floor are less likely to use long-lasting insecticidal nets (LLINs); however, the relationship between sleeping location and Plasmodium falciparum infection has not been investigated sufficiently. This study revealed whether sleeping location (bed vs floor) is associated with P. falciparum infection among children 7–59 months old. More than 60% of children slept on the floor. Younger children were significantly more likely to sleep in beds [odds ratio, OR 2·31 (95% confidence interval (CI) 2·02–2·67)]. Nearly 70% of children slept under LLINs the previous night. LLIN use among children who slept on the floor was significantly less than ones sleeping in beds [OR 0·49 (95% CI 0·35–0·68)]. The polymerase chain reaction (PCR) based P. falciparum infection rate and slide based infection rate were 65·2 and 29·7%, respectively. Both infections were significantly higher among children slept on the floor [OR1·51 (95% CI 1·08–2·10) for PCR base, OR 1·62 (95% CI 1·14–2·30) for slide base] while net availability was not significant. Sleeping location was also significant for slide based infection with fever (⩾37·5 °C) [2·03 (95% CI 1·14–3·84)] and high parasitemia cases (parasite ⩾2500 µL−1) [2·07 (95% CI 1·03–4·50)]. The results suggest that sleeping location has a direct bearing on the effectiveness of LLINs.
A triple hurdle model estimates cattle farmer willingness to adopt or expand prescribed grazing on pasture in the United States in response to a hypothetical incentive program. Interest in adoption/expansion is estimated first, then willingness to participate in the program, followed by intensity of participation measured as additional acres enrolled. The supply elasticity of enrolled acres with respect to the incentive is 0.13. Nonpecuniary factors inter alia farmer sentiment about stewardship, current farm management practices, farm location, and education are associated with farmer willingness to participate and with participation intensity.
Little is known about the impact of corn and energy prices on the profitability of irrigating corn in Tennessee. We evaluated the probability of a positive net present value (NPV) for center-pivot irrigation in Tennessee corn production. Three corn price series were employed to evaluate the effects of the shift in corn prices on the feasibility of irrigation. The recent rise in corn prices increased the probability of NPV being positive for irrigation investment. Future corn prices will need to remain high for investment in center-pivot irrigation to remain profitable under Tennessee growing conditions.
A multiobjective optimization model integrating with high-resolution geographical data was applied to examine the optimal switchgrass supply system in Tennessee that considers both feedstock cost and greenhouse gas (GHG) emissions in the system. Results suggest that the type of land converted into switchgrass production is crucial to both plant gate cost and GHG emissions of feedstock. In addition, a tradeoff relationship between cost and GHG emissions for the switchgrass supply is primarily driven by the type of land converted. The imputed cost of lowering GHG emissions in the feedstock supply system was also calculated based on the derived tradeoff curve.
Biofuel production from lignocellulosic biomass (LCB) is being advocated as an alternative to fossil-based transportation fuels in the United States. LCB-based biofuel production has the potential to mitigate greenhouse gas (GHG) emissions from the transportation sector and to enhance rural economic activity through more intense use of agricultural lands (English et al., 2006). The Renewable Fuel Standard (RFS) established in 2005 and revised in the Energy Independence and Security Act 2007 mandates 21 billion gallons of advanced biofuel (other than ethanol derived from corn starch) available for transportation use by 2022 with 16 billion gallons to be produced from LCB feedstock (U.S. Congress, 2007). Based on the recently revised One Billion Ton Update study (U. S. Department of Energy, 2011), considerable LCB feedstock, including dedicated energy crops, will be required to fulfill this goal. Notwithstanding the potential availability of LCB feedstock to meet the mandate, the cost of LCB feedstock will be an important factor influencing the sustainability of an LCB-based biofuel industrial sector.
By way of framing Manan Ahmed Asif's intriguing personal (and poetic) reflection entitled “Idol in the Archive” in this current issue of the Journal of Asian Studies, it must always be remembered that in August 1947, the old British Raj gave birth to not one but two independent nation-states, namely India and Pakistan. India became a “Sovereign Democratic Republic” when its Constitution came into effect on January 26, 1950, following adoption of its draft Constitution by its Constituent Assembly on November 26, 1949. Pakistan took a bit longer, becoming the “Islamic Republic of Pakistan” when its first Constitution came into effect on March 23, 1956. Furthermore, of course, Pakistan underwent secession of its Eastern Province with the founding of the “People's Republic of Bangladesh” in 1971. It is hardly an exaggeration to suggest that partition is the defining event of modern independent India and Pakistan, and, more than that, continues to be the defining event of India and Pakistan even after more than fifty years of independence.
Deterministic and stochastic yield response plateau functions were estimated to determine the expected profit-maximizing nitrogen rates, yields, and net returns for corn grown after corn, cotton, and soybeans. The stochastic response functions were more appropriate than their deterministic counterparts, and the linear response stochastic plateau described the data the best. The profit-maximizing nitrogen rates were similar for corn after corn, cotton, and soybeans, but relative to corn after corn, the expected corn yield plateaus increased by 12% and 16% after cotton and soybeans, respectively. Expected net returns increased for corn after cotton and soybeans relative to corn after corn.
This article investigates how information from cotton yield monitors influences the perceptions of within-field yield variability of cotton producers. Using yield distribution modeling techniques and survey data from cotton producers in 11 southeastern states, we find that cotton farmers who responded to the survey tend to underestimate within-field yield variability (by approximately 5-18%) when not using site-specific yield monitor information. Results further indicate that surveyed cotton farmers who responded to a specific question about yield monitors place a value of approximately $20/acre/year (on average) on the additional information about within-field yield variability that the yield monitor technology provides.
An influenza pandemic can overwhelm the capacities of hospitals, clinics, nursing facilities, and emergency services. The likelihood is that most of the individuals who are stricken will be cared for at home, and there is strong evidence that in-home caregivers bear a disproportionate risk of becoming infected. We reviewed the scientific literature after 2000 to identify steps that in-home caregivers can take to reduce the chances that they and other household members will become infected in the home. Personal hygiene, common masks, and technologies including air filters and UV light each offer incremental benefits, and in combination are expected to reduce a portion of the risk that household members face when caring for a member who has become infected. In pandemics and even seasonal epidemics, seemingly small steps can literally mean the difference between life and death, especially for in-home caregivers.
(Disaster Med Public Health Preparedness. 2011;5:266–271)
Precision farming information demanded by cotton producers is provided by various suppliers, including consultants, farm input dealerships, University Extension systems, and media sources. Factors associated with the decisions to select among information sources to search for precision farming information are analyzed using a multivariate probit regression accounting for correlation among the different selection decisions. Factors influencing these decisions are age, education, and income. These findings should be valuable to precision farming information providers who may be able to better meet their target clientele needs.
Many studies on the adoption of precision technologies have generally used logit models to explain the adoption behavior of individuals. This study investigates factors affecting the intensity of precision agriculture technologies adopted by cotton farmers. Particular attention is given to the role of spatial yield variability on the number of precision farming technologies adopted, using a count data estimation procedure and farm-level data. Results indicate that farmers with more within-field yield variability adopted a higher number of precision agriculture technologies. Younger and better educated producers and the number of precision agriculture technologies used were significantly correlated. Finally, farmers using computers for management decisions also adopted a higher number of precision agriculture technologies.
Personal digital assistants (PDA) and handheld global positioning systems (GPS) have become increasingly important in cotton production but little is known about their use. This research analyzed the adoption of PDA/handheld GPS devices in cotton production. A younger farmer who used a computer in farm management and had a positive perception of Extension had a greater likelihood of adopting the devices. In addition, farmers who used complementary remote sensing, plant mapping, and grid soil sampling information were more likely to use PDA/handheld GPS devices. Finally, the COTMAN in-field decision support program from Extension also positively impacted adoption.