5,871 research outputs found
The Dark (or the Light) Side of The Moon? Michigan\u27s Elimination of the Local Property Tax
For some, Senate Bill 1 was a bold and courageous move that held hope not only of breaking the twenty year legislative impasse on school finance reform, but also of providing a once-in-a-lifetime opportunity to reform public education
Genome-wide association study for calving performance using high-density genotypes in dairy and beef cattle
peer-reviewedBackground
Calving difficulty and perinatal mortality are prevalent in modern-day cattle production systems. It is well-established that there is a genetic component to both traits, yet little is known about their underlying genomic architecture, particularly in beef breeds. Therefore, we performed a genome-wide association study using high-density genotypes to elucidate the genomic architecture of these traits and to identify regions of the bovine genome associated with them.
Results
Genomic regions associated with calving difficulty (direct and maternal) and perinatal mortality were detected using two statistical approaches: (1) single-SNP (single nucleotide polymorphism) regression and (2) a Bayesian approach. Data included high-density genotypes on 770 Holstein-Friesian, 927 Charolais and 963 Limousin bulls. Several novel or previously identified genomic regions were detected but associations differed by breed. For example, two genomic associations, one each on chromosomes 18 and 2 explained 2.49 % and 3.13 % of the genetic variance in direct calving difficulty in the Holstein-Friesian and Charolais populations, respectively. Imputed Holstein-Friesian sequence data was used to refine the genomic regions responsible for significant associations. Several candidate genes on chromosome 18 were identified and four highly significant missense variants were detected within three of these genes (SIGLEC12, CTU1, and ZNF615). Nevertheless, only CTU1 contained a missense variant with a putative impact on direct calving difficulty based on SIFT (0.06) and Polyphen (0.95) scores. Using imputed sequence data, we refined a genomic region on chromosome 4 associated with maternal calving difficulty in the Holstein-Friesian population and found the strongest association with an intronic variant in the PCLO gene. A meta-analysis was performed across the three breeds for each calving performance trait to identify common variants associated with these traits in the three breeds. Our results suggest that a portion of the genetic variation in calving performance is common to all three breeds.
Conclusion
The genomic architecture of calving performance is complex and mainly influenced by many polymorphisms of small effect. We identified several associations of moderate effect size but the majority were breed-specific, indicating that breed-specific alleles exist for calving performance or that the linkage phase between genotyped allele and causal mutation varies between breeds
Microbial community dynamics and coexistence in a sulfide-driven phototrophic bloom
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bhatnagar, S., Cowley, E. S., Kopf, S. H., Pérez Castro, S., Kearney, S., Dawson, S. C., Hanselmann, K., & Ruff, S. E. Microbial community dynamics and coexistence in a sulfide-driven phototrophic bloom. Environmental Microbiome, 15(1),(2020): 3, doi:10.1186/s40793-019-0348-0.Background: Lagoons are common along coastlines worldwide and are important for biogeochemical element cycling, coastal biodiversity, coastal erosion protection and blue carbon sequestration. These ecosystems are frequently disturbed by weather, tides, and human activities. Here, we investigated a shallow lagoon in New England. The brackish ecosystem releases hydrogen sulfide particularly upon physical disturbance, causing blooms of anoxygenic sulfur-oxidizing phototrophs. To study the habitat, microbial community structure, assembly and function we carried out in situ experiments investigating the bloom dynamics over time.
Results: Phototrophic microbial mats and permanently or seasonally stratified water columns commonly contain multiple phototrophic lineages that coexist based on their light, oxygen and nutrient preferences. We describe similar coexistence patterns and ecological niches in estuarine planktonic blooms of phototrophs. The water column showed steep gradients of oxygen, pH, sulfate, sulfide, and salinity. The upper part of the bloom was dominated by aerobic phototrophic Cyanobacteria, the middle and lower parts by anoxygenic purple sulfur bacteria (Chromatiales) and green sulfur bacteria (Chlorobiales), respectively. We show stable coexistence of phototrophic lineages from five bacterial phyla and present metagenome-assembled genomes (MAGs) of two uncultured Chlorobaculum and Prosthecochloris species. In addition to genes involved in sulfur oxidation and photopigment biosynthesis the MAGs contained complete operons encoding for terminal oxidases. The metagenomes also contained numerous contigs affiliating with Microviridae viruses, potentially affecting Chlorobi. Our data suggest a short sulfur cycle within the bloom in which elemental sulfur produced by sulfide-oxidizing phototrophs is most likely reduced back to sulfide by Desulfuromonas sp.
Conclusions: The release of sulfide creates a habitat selecting for anoxygenic sulfur-oxidizing phototrophs, which in turn create a niche for sulfur reducers. Strong syntrophism between these guilds apparently drives a short sulfur cycle that may explain the rapid development of the bloom. The fast growth and high biomass yield of Chlorobi-affiliated organisms implies that the studied lineages of green sulfur bacteria can thrive in hypoxic habitats. This oxygen tolerance is corroborated by oxidases found in MAGs of uncultured Chlorobi. The findings improve our understanding of the ecology and ecophysiology of anoxygenic phototrophs and their impact on the coupled biogeochemical cycles of sulfur and carbon.This work was carried out at the Microbial Diversity summer course at the Marine Biological Laboratory in Woods Hole, MA. The course was supported by grants from National Aeronautics and Space Administration, the US Department of Energy, the Simons Foundation, the Beckman Foundation, and the Agouron Institute. Additional funding for SER was provided by the Marine Biological Laboratory
Authors Alliance Partner Program (A2P2) [Product Review]
The Authors Alliance Partner Program (A2P2; https://www.authorsalliance.org/a2p2/) is a recent addition to the educational content from the Authors Alliance. This nonprofit advocacy organization aims “to advance the interests of authors who want to serve the public good by sharing their creations broadly.” And this new initiative provides prêt-à -porter instructional material with the express purpose of supporting the scaling of rights–related programming—a goal that distinguishes A2P2 from other well-established and deeply valuable copyright-focused resources (Authors Alliance, 2020). While copyright touches nearly all we do in libraries, outreach in this area can often fall to scholarly communication or copyright librarians. As Schmidt (2019) notes, “providing copyright information services in the library has become part of the standard operations of academic libraries in the U.S.” We must, consequently, train ourselves up and stay current on copyright issues, as well as instruct our peers and our communities on copyright- and author rights–related concerns (Reeves, 2015; Norris, Tierney, & Dubach, 2019; Secker, Morrison, & Nilsson, 2019). We need to build resources on topics that are nuanced, evolving, and carry risk. These efforts take time, care, and confidence. For professionals who may well have varied and competing job responsibilities, time and confidence certainly may be at a premium (Charbonneau & Priehs, 2014)
Education Reform and the Limits of Policy: Lessons from Michigan
By examining a major set of education policy reforms undertaken in Michigan and across the country over the past 20-plus years, Addonizio and Kearney are able to reveal the varying success of innovations such as finance reform, state assessment of student performance, school accountability measures, charter schools, and schools of choice.https://research.upjohn.org/up_press/1234/thumbnail.jp
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