Food systems

Contributing institution: University of California at DavisPreviously hosted as part of Mann Library's Locale collection

The relevance of Regional Political Ecology for agriculture and food systems

The region as a concept continues to hold promise as a way of breaking through the many binaries that often divide political ecology. Operationalizing a regional political ecology approach allows the researcher to generate a large number of insights and conclusions that a more narrow disciplinary (disciplined) focus and non-scalar approach would miss; this is because important biophysical and social processes intersect with each another and work together to produce and/or mediate important outcomes for human and environmental well-being. The article draws on a number of cases to examine what comparison of political ecological research between regions could look like. I argue for a reinvigorated relationship between regional political ecology as an approach and agrifood systems as the object of study, and pose questions that can help shape this endeavor. Keywords: regional political ecology, regional comparisons, network political ecology, agriculture, food systems, agroecolog

"It just goes to kill Ticos": national market regulation and the political ecology of farmers' pesticide use in Costa Rica

This paper addresses pesticide residues on vegetables in developing countries through the specific case of Costa Rica.  Pesticide residues are often very high on vegetables in developing countries, generally considerably higher than in industrialized countries.  Using a political ecology approach, I combine qualitative and quantitative primary data with secondary data to answer two questions.  Why do farmers use pesticides in a manner that results in high levels of residues on vegetables?  And, how do markets with unequal regulatory strength affect farmers' pesticides use, and, by inference, the resulting exposure of different populations fed by different market segments?  While usually attributed to farmer ignorance, I argue that the pesticide residue problem arises from a triad of causes: higher efficacy of more residual and toxic pesticides, combined with many vegetables' biological trait of consecutive harvests, and a volatile vegetable market upon which farm household reproduction depends.  With high input costs and low farm gate prices, farmers in markets with minimal regulation will use more residual and toxic pesticides.  Using the idea of a double standard, I show that lax regulation in the open national market means that farmers are less cautious about residues on national market produce than export produce, and that some export farmers use the open national market as an outlet for their produce when they use highly residual pesticides.  Uneven regulations between North and South are manifested in farmer's management decisions, and lead to the injustice of higher residues in developing country vegetables. Keywords: pesticide residues; pesticide use; uneven regulation; Costa Rica; developing countries; national market vegetables; export vegetables; environmental injustic

Changes in students’ mental models from computational modeling of gene regulatory networks

Background: Computational modeling is an increasingly common practice for disciplinary experts and therefore necessitates integration into science curricula. Computational models afford an opportunity for students to investigate the dynamics of biological systems, but there is significant gap in our knowledge of how these activities impact student knowledge of the structures, relationships, and dynamics of the system. We investigated how a computational modeling activity affected introductory biology students’ mental models of a prokaryotic gene regulatory system (lac operon) by analyzing conceptual models created before and after the activity. Results: Students’ pre-lesson conceptual models consisted of provided, system-general structures (e.g., activator, repressor) connected with predominantly incorrect relationships, representing an incomplete mental model of gene regulation. Students’ post-lesson conceptual models included more context-specific structures (e.g., cAMP, lac repressor) and increased in total number of structures and relationships. Student conceptual models also included higher quality relationships among structures, indicating they learned about these context-specific structures through integration with their expanding mental model rather than in isolation. Conclusions: Student mental models meshed structures in a manner indicative of knowledge accretion while they were productively re-constructing their understanding of gene regulation. Conceptual models can inform instructors about how students are relating system structures and whether students are developing more sophisticated models of system-general and system-specific dynamics

Challenging Endocrinology Students with a Critical Thinking Workbook

This is the accepted manuscript of an article published in Advances in Physiology Education. The version of record can be found here: https://doi.org/10.1152/advan.00101.2019A central goal of science education is to help students develop higher order thinking skills to enable them to face the challenges of life. Accordingly, science instructors are now urged to craft their classrooms such that they serve not only as spaces for disseminating information, but also an arena through which students are encouraged to think scientifically and develop critical thinking skills. This project aimed to develop a workbook that helps postsecondary students learn endocrinology and engages them in critical thinking. Each of the five chapters focus on a different topic rooted within core biological concepts relevant to endocrinology. Such topics were identified upon cross referencing seminal reports on science education. Tenants of Numrich’s Sequence of Critical Thinking Tasks were used to guide the development of chapter sections with the intent of engaging students in critical thinking over time by way of practice and scaffolded guidance. Chapter sections include modeling, event sequencing, clinical application, research and communication, and simulation, each of which target a different repertoire of skills presented in Numrich’s framework. Students’ learning, experiences, and behaviors were used to evaluate the workbook and inform the revision of the workbook into the publicly-available second edition

Detection of OH absorption against PSR B1849+00

We have searched for OH absorption against seven pulsars using the Arecibo telescope. In both OH mainlines (at 1665 and 1667 MHz), deep and narrow absorption features were detected toward PSR B1849+00. In addition, we have detected several absorption and emission features against B33.6+0.1, a nearby supernova remnant (SNR). The most interesting result of this study is that a pencil-sharp absorption sample against the PSR differs greatly from the large-angle absorption sample observed against the SNR. If both the PSR and the SNR probe the same molecular cloud then this finding has important implications for absorption studies of the molecular medium, as it shows that the statistics of absorbing OH depends on the size of the background source. We also show that the OH absorption against the PSR most likely originates from a small (<30 arcsec) and dense (>10^5 cm^-3) molecular clump.Comment: 12 pages, 8 figures. Accepted for publication in Ap

Community Supported Agriculture is thriving in the Central Valley

Community Supported Agriculture operations (CSAs) have grown rapidly in recent years. The original model, in which members support a farming operation by paying for produce in advance and receive a share of the farm's produce in return, has been adapted, with much innovation. Since little research existed on CSAs in the Central Valley, we surveyed and carried out in-depth interviews with 54 CSA farmers and two CSA organizers in the Central Valley and surrounding foothills. Here we focus on four aspects of these CSA operations: type, economic viability, farmer characteristics and farm attributes. We found two main CSA models, box and membership/share. Fifty-four percent of the CSAs reported being profitable, and the average gross sales per acre were $9,084. CSA farmers are diverse in political orientation, yet are generally younger, better educated and more likely to be women than the general farming population. CSA farms are relatively small, with a median size of 20 acres; have a median membership of 60 (585 average); use agroecological methods; cultivate agrobiodiversity; and utilize growing practices that generally meet or exceed National Organic Program standards

Modern Electronic Techniques Applied to Physics and Engineering

Contains reports on seven research projects.Office of Scientific Research and Development (OSRD) OEMsr-26

The ENCODE Project at UC Santa Cruz

The goal of the Encyclopedia Of DNA Elements (ENCODE) Project is to identify all functional elements in the human genome. The pilot phase is for comparison of existing methods and for the development of new methods to rigorously analyze a defined 1% of the human genome sequence. Experimental datasets are focused on the origin of replication, DNase I hypersensitivity, chromatin immunoprecipitation, promoter function, gene structure, pseudogenes, non-protein-coding RNAs, transcribed RNAs, multiple sequence alignment and evolutionarily constrained elements. The ENCODE project at UCSC website () is the primary portal for the sequence-based data produced as part of the ENCODE project. In the pilot phase of the project, over 30 labs provided experimental results for a total of 56 browser tracks supported by 385 database tables. The site provides researchers with a number of tools that allow them to visualize and analyze the data as well as download data for local analyses. This paper describes the portal to the data, highlights the data that has been made available, and presents the tools that have been developed within the ENCODE project. Access to the data and types of interactive analysis that are possible are illustrated through supplemental examples