Physical vapor deposited (PVD) molybdenum disulfide (nominal composition MoS2) is employed as a thin film solid lubricant for extreme environments where liquid lubricants are not viable. The tribological properties of MoS2 are highly dependent on morphological attributes such as film thickness, orientation, crystallinity, film density, and stoichiometry. These structural characteristics are controlled by tuning the PVD process parameters, yet undesirable alterations in the structure often occur due to process variations between deposition runs. Nondestructive film diagnostics can enable improved yield and serve as a means of tuning a deposition process, thus enabling quality control and materials exploration. Grazing incidence X-ray diffraction (GIXRD) for MoS2 film characterization provides valuable information about film density and grain orientation (texture). However, the determination of film stoichiometry can only be indirectly inferred via GIXRD. The combination of density and microstructure via GIXRD with chemical composition via grazing incidence X-ray fluorescence (GIXRF) enables the isolation and decoupling of film density, composition, and microstructure and their ultimate impact on film layer thickness, thereby improving coating thickness predictions via X-ray fluorescence. We have augmented an existing GIXRD instrument with an additional X-ray detector for the simultaneous measurement of energy-dispersive X-ray fluorescence spectra during the GIXRD analysis. This combined GIXRD/GIXRF analysis has proven synergetic for correlating chemical composition to the structural aspects of MoS2 films provided by GIXRD. We present the usefulness of the combined diagnostic technique via exemplar MoS2 film samples and provide a discussion regarding data extraction techniques of grazing angle series measurements.

Large language models (LLMs) offer new research possibilities for social scientists, but their potential as “synthetic data” is still largely unknown. In this paper, we investigate how accurately the popular LLM ChatGPT can recover public opinion, prompting the LLM to adopt different “personas” and then provide feeling thermometer scores for 11 sociopolitical groups. The average scores generated by ChatGPT correspond closely to the averages in our baseline survey, the 2016–2020 American National Election Study (ANES). Nevertheless, sampling by ChatGPT is not reliable for statistical inference: there is less variation in responses than in the real surveys, and regression coefficients often differ significantly from equivalent estimates obtained using ANES data. We also document how the distribution of synthetic responses varies with minor changes in prompt wording, and we show how the same prompt yields significantly different results over a 3-month period. Altogether, our findings raise serious concerns about the quality, reliability, and reproducibility of synthetic survey data generated by LLMs.

The Sheep Mountain juniper bark net, originally thought to be of Paleoindian age, was redated by Sundstrom and Walker (2021) to the Late Prehistoric period. Although the original investigators convincingly argued that the net was intended for use with mountain sheep or deer, Sundstrom and Walker suggest it was used to trap small game such as rabbits or sage grouse. Unfortunately, the authors ignore important information presented by the original investigators and misrepresent the archaeological record of the immediate area. The Sheep Mountain net is still best interpreted as designed for use to trap mountain sheep and deer.

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.

A Just-Pope model was developed to assess tillage, nitrogen, weather, and pest effects on risk for cotton grown after alternative winter cover crops. Yield risk for cotton after hairy vetch was less than for cotton with no winter cover when no nitrogen fertilizer was used to Supplement the vetch nitrogen. However, because cotton after vetch has a higher production cost, farmers growing conventionally tilled cotton may be slow to adopt because risk-return tradeoffs may be unacceptable under risk neutrality and risk aversion. For risk-averse farmers who have already adopted no tillage, cotton grown after hairy vetch is risk efficient.

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.

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.

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.

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.

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.

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.

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.

This manuscript reviews a series of experiments which support the notion that the cerebellum and more specifically the cerebellar cortex is principally involved in real time operations required for the regulation of coordinated motor activity. Experiments are reviewed which illustrate: (1) that the climbing fiber inputs to Purkinje cells can induce a short-lasting enhancement of their responses to mossy fiber-granule cell-parallel fiber inputs, (2) that the cerebellum is not essential for the acquisition and performance of the classically conditioned nictitating membrane reflex (NMR) of the rabbit, and (3) that the observations resulting from the microinjection of lidocaine and multiple single unit recordings within the brainstem support the notion that cell populations in this region may participate in establishing the modifications in neuronal interactions required for the acquisition of the conditioned NMR. In addition, preliminary data are shown comparing the capacity of a normal subject and a patient with a massive ipsilateral cerebellar stroke to learn certain tracing tasks and to redraw these learned tracing movements 90° to the orientation of the original image. The data support the notion that the cerebellum is essential, not for the initial learning of the tracing movement, but rather for performing the learned movement with the required rotation of the original image.

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.

This study identified the factors that influenced whether farmers in theSoutheastern United States perceived an improvement in environmental qualityfrom adopting precision farming technologies (PFTs). Farmers with largerfarms or higher yields were more likely to believe that they observedpositive externalities associated with PFTs. Farmers who found PFTsprofitable or who believed input reduction was important had higherprobabilities whereas those with higher incomes or who were more dependenton farm income were less likely to perceive such benefits. Interestingly,the importance of environmental quality and length of time using PFTs werenot found to affect the probability of perceiving an improvement inenvironmental quality.

The federal government has supported and continues to support or share in the support, financially and technically, of several regional pest management programs. Implicit in continued federal support is the concept that the benefits of the program to society exceed the governmental portion of the costs. As these programs are evaluated and consideration is given to discontinuing federal support, improved estimates of program benefits, or costs of discontinuing, are needed.

The objective of this study was to identify and quantify the expected effects in terms of agricultural output, insecticide use, and production costs of discontinuing a regional boll weevil suppression program on the Texas High Plains. Results of this study are useful to governmental decision makers, local producers, environmentalists and economists.

Quantities of insecticides used per acre by cotton producers in the Lower Rio Grande Valley of Texas are among the nation's highest. This is due to the presence of many different insect pests and especially to their increasing tolerance to insecticides. As insects become resistant to insecticides, farmers tend to increase the number of insecticide applications, further compounding the problem. Even using large amounts of insecticides, control of damaging insects has been unsatisfactory.

Typically, a long-season cotton variety, requiring a 160 to 180 day season, is grown. Because the probability of rainfall is much greater in August than in July [4], most harvesting can be expected in August.

If adoption of herbicide-resistant seed and adoption of conservation-tillage practices are determined simultaneously, adoption of herbicide-resistant seed could indirectly reduce soil erosion and adoption of conservation-tillage practices could indirectly reduce residual herbicide use and increase farm profits. Our objective was to evaluate the relationship between these two technologies for Tennessee cotton production. Evidence from Bayes' theorem and a two-equation logit model suggested a simultaneous relationship. Mean elasticities for acres in herbicide-resistant seed with respect to the probability of adopting conservation-tillage practices and acres in conservation-tillage practices with respect to the probability of adopting herbicide-resistant seed were 1.74 and 0.24, respectively.