205 research outputs found
Benefits to Qualitative Data Quality with Multiple Coders: Two Case Studies in Multi-coder Data Analysis
Qualitative research methods contend with debates surrounding subjectivity and bias. Researchers use a variety of techniques to help ensure data trustworthiness. One such technique is to involve multiple coders in data analysis. The deliberative nature of codebook development among multiple coders produces rich data analysis that may not otherwise be achieved with a single (or even two) researcher(s). In this manuscript, we make a plea for researchers and journals to include data analysis procedures and descriptions in published literature. In addition, we illustrate minimal reporting of qualitative data analysis processes through a synthesis of 21 years of agricultural best management practice adoption literature. We present two rural agricultural case studies on multi-coder team codebook development and intercoder reliability processes specific to interviews, focus groups, and content analysis. Overall, we argue that multi-coder teams can improve data quality, and reporting data analysis procedures can mitigate implications of subjectivity in qualitative methods
Synthesizing Conservation Motivations and Barriers: What Have We Learned from Qualitative Studies of Farmers’ Behaviors in the United States?
Since 2011, qualitative studies examining adoption of conservation practices and programs (CPPs) have burgeoned. This article presents a systematic review of all U.S.-based qualitative investigations into CPP adoption since 1996. We found three themes are discussed primarily as motivating adoption: farmer characteristics, environmental awareness, and trust in information sources. Four themes are discussed primarily as barriers to adoption: farm management, negative perceptions of a conservation practice, perceptions that adoption is a risk, and land tenure. Four themes were discussed as both motivations and barriers: economic factors, social norms, perceptions of government programs, and farm characteristics. Overall, we found farmers’ economic and management needs and their perceived and actual limitations to conservation behavior influenced adoption. Implications of our findings for policymakers and practitioners include promoting systems-based conservation strategies and stressing the benefits of conservation practices
Do advisors perceive climate change as an agricultural risk? An in-depth examination of Midwestern U.S. Ag advisors’ views on drought, climate change, and risk management
Through the lens of the Health Belief Model and Protection Motivation Theory, we analyzed interviews of 36 agricultural advisors in Indiana and Nebraska to understand their appraisals of climate change risk, related decision making processes and subsequent risk management advice to producers. Most advisors interviewed accept that weather events are a risk for US Midwestern agriculture; however, they are more concerned about tangible threats such as crop prices. There is not much concern about climate change among agricultural advisors. Management practices that could help producers adapt to climate change were more likely to be recommended by conservation and Extension advisors, while financial and crop advisors focused more upon season-to-season decision making (e.g., hybrid seeds and crop insurance). We contend that the agricultural community should integrate long-term thinking as part of farm decision making processes and that agricultural advisors are in a prime position to influence producers. In the face of increasing extreme weather events, climatologists and advisors should work more closely to reach a shared understanding of the risks posed to agriculture by climate change
Cross-correlating Carbon Monoxide Line-intensity Maps with Spectroscopic and Photometric Galaxy Surveys
Line-intensity mapping (LIM or IM) is an emerging field of observational
work, with strong potential to fit into a larger effort to probe large-scale
structure and small-scale astrophysical phenomena using multiple complementary
tracers. Taking full advantage of such complementarity means, in part,
undertaking line-intensity surveys with galaxy surveys in mind. We consider the
potential for detection of a cross-correlation signal between COMAP and blind
surveys based on photometric redshifts (as in COSMOS) or based on spectroscopic
data (as with the HETDEX survey of Lyman- emitters). We find that
obtaining accuracy in redshifts and
sources per Mpc with spectroscopic redshift determination
should enable a CO-galaxy cross spectrum detection significance at least twice
that of the CO auto spectrum. Either a future targeted spectroscopic survey or
a blind survey like HETDEX may be able to meet both of these requirements.Comment: 19 pages + appendix (31 pages total), 16 figures, 6 tables; accepted
for publication in Ap
Cryogenic 160-GHz MMIC Heterodyne Receiver Module
A cryogenic 160-GHz MMIC heterodyne receiver module has demonstrated a system noise temperature of 100 K or less at 166 GHz. This module builds upon work previously described in Development of a 150-GHz MMIC Module Prototype for Large-Scale CMB Radiation (NPO-47664), NASA Tech Briefs, Vol. 35, No. 8 (August 2011), p. 27. In the original module, the local oscillator signal was saturating the MMIC low-noise amplifiers (LNAs) with power. In order to suppress the local oscillator signal from reaching the MMIC LNAs, the W-band (75 110 GHz) signal had to be filtered out before reaching 140 170 GHz. A bandpass filter was developed to cover 120 170 GHz, using microstrip parallel-coupled lines to achieve the desired filter bandwidth, and ensure that the unwanted W-band local oscillator signal would be sufficiently suppressed. With the new bandpass filter, the entire receiver can work over the 140 180-GHz band, with a minimum system noise temperature of 460 K at 166 GHz. The module was tested cryogenically at 20 K ambient temperature, and it was found that the receiver had a noise temperature of 100 K over an 8-GHz bandwidth. The receiver module now includes a microstrip bandpass filter, which was designed to have a 3-dB bandwidth of approximately 120-170 GHz. The filter was fabricated on a 3-mil-thick alumina substrate. The filter design was based on a W-band filter design made at JPL and used in the QUIET (Q/U Imaging ExperimenT) radiometer modules. The W-band filter was scaled for a new center frequency of 150 GHz, and the microstrip segments were changed accordingly. Also, to decrease the bandwidth of the resulting scaled design, the center gaps between the microstrip lines were increased (by four micrometers in length) compared to the gaps near the edges. The use of the 150-GHz bandpass filter has enabled the receiver module to function well at room temperature. The system noise temperature was measured to be less than 600 K (at room temperature) from 154 to 168 GHz. Additionally, the use of a W-band isolator between the receiver module and the local oscillator source also improved the noise temperature substantially. This may be because the mixer was presented with a better impedance match with the use of the isolator. Cryogenic testing indicates a system noise temperature of 100 K or less at 166 GHz. Prior tests of the MMIC amplifiers alone have resulted in a system noise temperature of 65.70 K in the same frequency range (.160 GHz) when cooled to an ambient temperature of 20 K. While other detector systems may be slightly more sensitive (such as SIS mixers), they require more cooling (to 4 K ambient) and are not as easily scalable to build a large array, due to the need for large magnets and other equipment. When cooled to 20 K, this receiver module achieves approximately 100 K system noise temperature, which is slightly higher than single-amplifier module results obtained at JPL (65.70 K when an amplifier is corrected for back-end noise contributions). If this performance can be realized in practice, and a scalable array can be produced, the impact on cosmic microwave background experiments, astronomical and Earth spectroscopy, interferometry, and radio astronomy in general will be dramatic
Compact, Miniature MMIC Receiver Modules for an MMIC Array Spectrograph
A single-pixel prototype of a W-band detector module with a digital back-end was developed to serve as a building block for large focal-plane arrays of monolithic millimeter-wave integrated circuit (MMIC) detectors. The module uses low-noise amplifiers, diode-based mixers, and a WR10 waveguide input with a coaxial local oscillator. State-of-the-art InP HEMT (high electron mobility transistor) MMIC amplifiers at the front end provide approximately 40 dB of gain. The measured noise temperature of the module, at an ambient temperature of 300 K, was found to be as low as 450 K at 95 GHz. The modules will be used to develop multiple instruments for astrophysics radio telescopes, both on the ground and in space. The prototype is being used by Stanford University to characterize noise performance at cryogenic temperatures. The goal is to achieve a 30-50 K noise temperature around 90 GHz when cooled to a 20 K ambient temperature. Further developments include characterization of the IF in-phase (I) and quadrature (Q) signals as a function of frequency to check amplitude and phase; replacing the InP low-noise amplifiers with state-of-the-art 35-nm-gate-length NGC low-noise amplifiers; interfacing the front-end module with a digital back-end spectrometer; and developing a scheme for local oscillator and IF distribution in a future array. While this MMIC is being developed for use in radio astronomy, it has the potential for use in other industries. Applications include automotive radar (both transmitters and receivers), communication links, radar systems for collision avoidance, production monitors, ground-penetrating sensors, and wireless personal networks
“Safer to plant corn and beans”? Navigating the challenges and opportunities of agricultural diversification in the U.S. Corn Belt
Agricultural diversification in the Midwestern Corn Belt has the potential to improve socioeconomic and environmental outcomes by buffering farmers from environmental and economic shocks and improving soil, water, and air quality. However, complex barriers related to agricultural markets, individual behavior, social norms, and government policy constrain diversification in this region. This study examines farmer perspectives regarding the challenges and opportunities for both corn and soybean production and agricultural diversification strategies. We analyze data from 20 focus groups with 100 participants conducted in Indiana, Illinois, and Iowa through a combined inductive and deductive approach, drawing upon interpretive grounded theory. Our results suggest that when identifying challenges and opportunities, participants center economics and market considerations, particularly income, productivity, and market access. These themes are emphasized both as benefits of the current corn-soybean system, as well as challenges for diversification. Additionally, logistical, resource and behavioral hurdles– including the comparative difficulty and time required to diversify, and constraints in accessing land, labor, and technical support– are emphasized by participants as key barriers to diversification. Agricultural policies shape these challenges, enhancing the comparative advantage and decreasing the risk of producing corn and soybeans as compared to diversified products. Meanwhile, alternative marketing arrangements, farmer networks, family relationships, and improved soil health are highlighted as important opportunities for diversification. We contextualize our findings within the theories of reasoned action and diffusion of innovation, and explore their implications for farmer engagement, markets, and agricultural policy, and the development of additional resources for business and technical support.This article is published as Traldi, R., Asprooth, L., M. Usher, E. et al. “Safer to plant corn and beans”? Navigating the challenges and opportunities of agricultural diversification in the U.S. Corn Belt. Agric Hum Values (2024). https://doi.org/10.1007/s10460-024-10570-7. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted
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