De-Risking Agriculture: The Basic Economics of Crop Insurance Versus Sensor-Driven Informatics

Governments and donors frequently subsidize crop insurance to mitigate agricultural risks from weather and pests. This approach is costly, with taxpayers funding significant subsidies that often benefit financial services providers more than farmers. Efforts to reduce program costs by triggering payments on area-wide or related indexing schemes are impeded by basis risk—compensating unaffected farmers while failing to pay some farmers whose crops failed. Access to accurate weather data is crucial for addressing basis risk and properly aligning indemnity pools with actual crop failures across regions and seasons. We argue that investing in timely, locally relevant weather data collection, access, and associated informatic services offers greater potential returns than subsidizing conventional crop insurance. These investments yield both immediate and long-term benefits through enhanced informatics products that help farmers prevent or minimize crop losses as their current and future seasons unfold. Over time, these informatics also help better align research and seed system development with variable cropping environments. Moreover, unlike insurance, well-calibrated crop informatic products not only reduce risk (by potentially lowering crop yield and profit variability), they can also increase farm productivity (thereby increasing crop output or profits) and thus enhance farm families’ economic well-being over the long-term

An Experiential Report on the Thayer Method of Teaching across College-Level Chemistry, Biology, Math, and Physics Courses

The Thayer method of instruction is a little-known active learning technique that dates back to 1817 at the U.S. Military Academy. This study describes the implementation and statistical evaluation of an adaptation of the Thayer method in a variety of college science and math courses. All courses had five characteristics in common: (i) students were given a daily reading schedule and instructed to prepare before class, (ii) each class started with a question and answer session, (iii) class time minimized the use of lecture, (iv) class time maximized the use of active learning, and (v) students were frequently quizzed. A total of 51 sections across chemistry, biology, math, and physics taught by eight professors involving 542 students were used. Students were surveyed at the beginning and the end of the semester on their attitudes toward teaching methods using a 5-point Likert scale. The data were analyzed using the nonparametric Wilcoxon rank-sum test. The results show three outcomes: (i) students prefer the modified Thayer method over a traditional lecture method, (ii) students report feeling more encouraged to stay in college, and (iii) students report no difference in the amount of time that they spend on reading or working on problems. These three results are encouraging amid efforts to educate and retain STEM students. The modified Thayer method should be considered by those using or seeking to use an active learning technique

Reticulate evolution: frequent introgressive hybridization among chinese hares (genus lepus) revealed by analyses of multiple mitochondrial and nuclear DNA loci

<p>Abstract</p> <p>Background</p> <p>Interspecific hybridization may lead to the introgression of genes and genomes across species barriers and contribute to a reticulate evolutionary pattern and thus taxonomic uncertainties. Since several previous studies have demonstrated that introgressive hybridization has occurred among some species within <it>Lepus</it>, therefore it is possible that introgressive hybridization events also occur among Chinese <it>Lepus </it>species and contribute to the current taxonomic confusion.</p> <p>Results</p> <p>Data from four mtDNA genes, from 116 individuals, and one nuclear gene, from 119 individuals, provides the first evidence of frequent introgression events via historical and recent interspecific hybridizations among six Chinese <it>Lepus </it>species. Remarkably, the mtDNA of <it>L. mandshuricus </it>was completely replaced by mtDNA from <it>L. timidus </it>and <it>L. sinensis</it>. Analysis of the nuclear DNA sequence revealed a high proportion of heterozygous genotypes containing alleles from two divergent clades and that several haplotypes were shared among species, suggesting repeated and recent introgression. Furthermore, results from the present analyses suggest that Chinese hares belong to eight species.</p> <p>Conclusion</p> <p>This study provides a framework for understanding the patterns of speciation and the taxonomy of this clade. The existence of morphological intermediates and atypical mitochondrial gene genealogies resulting from frequent hybridization events likely contribute to the current taxonomic confusion of Chinese hares. The present study also demonstrated that nuclear gene sequence could offer a powerful complementary data set with mtDNA in tracing a complete evolutionary history of recently diverged species.</p

Glaciation Effects on the Phylogeographic Structure of Oligoryzomys longicaudatus (Rodentia: Sigmodontinae) in the Southern Andes

The long-tailed pygmy rice rat Oligoryzomys longicaudatus (Sigmodontinae), the major reservoir of Hantavirus in Chile and Patagonian Argentina, is widely distributed in the Mediterranean, Temperate and Patagonian Forests of Chile, as well as in adjacent areas in southern Argentina. We used molecular data to evaluate the effects of the last glacial event on the phylogeographic structure of this species. We examined if historical Pleistocene events had affected genetic variation and spatial distribution of this species along its distributional range. We sampled 223 individuals representing 47 localities along the species range, and sequenced the hypervariable domain I of the mtDNA control region. Aligned sequences were analyzed using haplotype network, Bayesian population structure and demographic analyses. Analysis of population structure and the haplotype network inferred three genetic clusters along the distribution of O. longicaudatus that mostly agreed with the three major ecogeographic regions in Chile: Mediterranean, Temperate Forests and Patagonian Forests. Bayesian Skyline Plots showed constant population sizes through time in all three clusters followed by an increase after and during the Last Glacial Maximum (LGM; between 26,000–13,000 years ago). Neutrality tests and the “g” parameter also suggest that populations of O. longicaudatus experienced demographic expansion across the species entire range. Past climate shifts have influenced population structure and lineage variation of O. longicaudatus. This species remained in refugia areas during Pleistocene times in southern Temperate Forests (and adjacent areas in Patagonia). From these refugia, O. longicaudatus experienced demographic expansions into Patagonian Forests and central Mediterranean Chile using glacial retreats