76 research outputs found

    Marketing and value-added opportunities with alternative swine systems

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    Cindy Madsen is a member of Audubon County Family Farms, a group of producers who believe in healthy farms raising healthy families. They work together to market their products directly to the consumer. Four producers use hooped structures in their hog production, two\u27sell chickens and eggs, one has antibiotic-free beef, as well as other products. All have very diverse, sustainable farming systems. It helps to have a state-inspected small processor available 20 miles from Audubon. Gary Malenke of Sioux-Preme Packing shared insights from the packer\u27s perspective. His company\u27s primary business had used mostly frozen carcasses until they began working with Farmland Foods and started to custom cut their own hogs in early 1997. In a constantly changing business, he said Sioux-Preme had trouble establishing an identity in a very competitive primal cuts market. One strategy has been to focus on lighter weight pigs, which work well for food service. To differentiate themselves, they went to customers not being served by the mainstream packers

    How Genre-Trained Tutors Affect Student Writing and Perceptions of the Writing Center

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    Writing center scholars have long debated whether writers are best served by “generalist” tutors trained in writing center pedagogy or “specialist” tutors with insider knowledge about a course’s content or discipline-specific discourse conventions. A potential compromise that has emerged is training tutors in the purposes and features of specific genres. The writing center literature showcases many different approaches to genre training. However, little empirical research, if any, has explored how tutors’ genre knowledge affects session outcomes. The present study used a mixed-methods approach to compare session outcomes for students who worked with generalist and genre-trained tutors. We analyzed pre-consultation and revised literature review drafts to determine whether students who worked with tutors trained in the genre of literature reviews improved their drafts more or revised their drafts differently than students who worked with generalist tutors. Additionally, we performed a qualitative analysis of student reflections about their writing processes to explore how tutor training impacts students’ impressions of their consultations. Findings indicated that students who worked with genre-trained tutors revised their drafts more substantively than did students who worked with generalist tutors. Moreover, students who worked with genre-trained tutors left with notably better and richer impressions of their consultations

    Cytochrome P450 2B diversity and dietary novelty in the herbivorous, desert woodrat (Neotoma lepida)

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    pre-printDetoxification enzymes play a key role in plant-herbivore interactions, contributing to the on-going evolution of ecosystem functional diversity. Mammalian detoxification systems have been well studied by the medical and pharmacological industries to understand human drug metabolism; however, little is known of the mechanisms employed by wild herbivores to metabolize toxic plant secondary compounds. Using a wild rodent herbivore, the desert woodrat (Neotoma lepida), we investigated genomic structural variation, sequence variability, and expression patterns in a multigene subfamily involved in xenobiotic metabolism, cytochrome P450 2B (CYP2B). We hypothesized that differences in CYP2B expression and sequence diversity could explain differential abilities of woodrat populations to consume native plant toxins. Woodrats from two distinct populations were fed diets supplemented with either juniper (Juniperus osteosperma) or creosote bush (Larrea tridentata), plants consumed by woodrats in their respective desert habitats. We used Southern blot and quantitative PCR to determine that the genomic copy number of CYP2B in both populations was equivalent, and similar in number to known rodent copy number. We compared CYP2B expression patterns and sequence diversity using cloned hepatic CYP2B cDNA. The resulting sequences were very diverse, and clustered into four major clades by amino acid similarity. Sequences from the experimental treatments were distributed non-randomly across a CYP2B tree, indicating unique expression patterns from woodrats on different diets and from different habitats. Furthermore, within each major CYP2B clade, sequences shared a unique combination of amino acid residues at 13 sites throughout the protein known to be important for CYP2B enzyme function, implying differences in the function of each major CYP2B variant. This work is the most comprehensive investigation of the genetic diversity of a detoxification enzyme subfamily in a wild mammalian herbivore, and contributes an initial genetic framework to our understanding of how a wild herbivore responds to critical changes in its diet

    Myosin Vc Interacts with Rab32 and Rab38 Proteins and Works in the Biogenesis and Secretion of Melanosomes

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    Class V myosins are actin-based motors with conserved functions in vesicle and organelle trafficking. Herein we report the discovery of a function for Myosin Vc in melanosome biogenesis as an effector of melanosome-associated Rab GTPases. We isolated Myosin Vc in a yeast two-hybrid screening for proteins that interact with Rab38, a Rab protein involved in the biogenesis of melanosomes and other lysosome-related organelles. Rab38 and its close homolog Rab32 bind to Myosin Vc but not to Myosin Va or Myosin Vb. Binding depends on residues in the switch II region of Rab32 and Rab38 and regions of the Myosin Vc coiled-coil tail domain. Myosin Vc also interacts with Rab7a and Rab8a but not with Rab11, Rab17, and Rab27. Although Myosin Vc is not particularly abundant on pigmented melanosomes, its knockdown in MNT-1 melanocytes caused defects in the trafficking of integral membrane proteins to melanosomes with substantially increased surface expression of Tyrp1, nearly complete loss of Tyrp2, and significant Vamp7 mislocalization. Knockdown of Myosin Vc in MNT-1 cells more than doubled the abundance of pigmented melanosomes but did not change the number of unpigmented melanosomes. Together the data demonstrate a novel role for Myosin Vc in melanosome biogenesis and secretion

    Louse flies in Azorean and mainland populations of four Passeriformes species_a new perspective to parasite Island syndromes

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    Environmental Sciences & Ecology ; ParasitologyHippoboscid flies, also known as louse flies, are obligate blood-feeders ectoparasites of birds and mammals. By studying louse fly parasites of four Passeriformes species, Eurasian blackbird (Turdus merula), Eurasian blackcap (Sylvia atricapilla), common chaffinch (Fringilla coelebs) and European robin (Erithacus rubecula), with dissimilar time of colonization of Azores islands, we tested whether: (i) island host populations have lower parasite richness than the mainland one; (ii) island host populations undergo higher parasite prevalence, mean intensities and mean abundance than the mainland one; (iii) island parasite diversity are composed exclusively by specific parasites and (iv) parasite richness is positively correlated with the island area and proximity to the continent. For these purposes, 775 birds were sampled for presence of louse flies, by modified fumigation chamber method, from Azores Islands (S˜ao Miguel, Terceira and Flores) and Portugal mainland. Insular and mainland parasite assemblages were statistically compared. We record for the first time to Azores, Ornithomya fringillina and Icosta minor from Portugal mainland. Louse flies had highest prevalence and abundance from Azores Islands compared to those observed in mainland birds, especially blackbirds. The insular parasite diversity of Azores blackbirds, blackcaps and chaffinches was richer than the one observed in mainland population. None of the hippoboscid flies observed on the islands and mainland were host-specific. Thus, our findings provide an upgrade of parasite island syndromes knowledge, in the context of the ectoparasites, namely to the ippoboscid flies case.info:eu-repo/semantics/publishedVersio

    Persistence of single species of symbionts across multiple closelyrelated host species

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    Some symbiont species are highly host-specific, inhabiting only one or a very few host species, and typically have limited dispersal abilities. When they do occur on multiple host species, populations of such symbionts are expected to become genetically structured across these different host species, and this may eventually lead to new symbiont species over evolutionary timescales. However, a low number of dispersal events of symbionts between host species across time might be enough to prevent population structure and species divergence. Overall, processes of evolutionary divergence and the species status of most putative multi-host symbiont systems are yet to be investigated. Here, we used DNA metabarcoding data of 6,023 feather mites (a total of 2,225 OTU representative sequences) from 147 infracommunities (i.e., the assemblage consisting of all mites of different species collected from the same bird host individual) to investigate patterns of population genetic structure and species status of three different putative multi-host feather mite species Proctophyllodes macedo Vitzthum, 1922, Proctophyllodes motacillae Gaud, 1953, and Trouessartia jedliczkai (Zimmerman, 1894), each of which inhabits a variable number of different closely related wagtail host species (genus Motacilla). We show that mite populations from different host species represent a single species. This pattern was found in all the mite species, suggesting that each of these species is a multi-host species in which dispersal of mites among host species prevents species divergence. Also, we found evidence of limited evolutionary divergence manifested by a low but significant level of population genetic structure among symbiont populations inhabiting different host species. Our study agrees with previous studies showing a higher than expected colonization opportunities in host-specific symbionts. Indeed, our results support that these dispersal events would allow the persistence of multi-host species even in symbionts with limited dispersal capabilities, though additional factors such as the geographical structure of some bird populations may also play a role.This work was supported by the MINECO CGL2011-24466 to RJ and CGL2015-69650-P to RJ and DS

    Niche construction and the transition to herbivory: Phenotype switching and the organization of new nutritional modes

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    Gut microbiota have played important roles in the evolutionary transition from carnivory to herbivory. In the evolution of ruminants, three modes of macrobe-microbe symbiosis have facilitated the phenotypic switch into a new nutritional mode. Mutualistic microbes acquired during birth enable the building of the rumen (developmental symbiosis), the digestion of plant fiber (nutritional symbiosis), and the detoxification of plant toxins (protective symbiosis). These symbioses created a new plant dietary niche through two types of niche construction: “perturbational niche construction,” a phenotypic process whereby gut microbes initiate the building of a mature rumen from the non-functional anlagen of this stomach region; and “mediational niche construction,” whereby microbe-induced changes alter how the animal experiences environmental resources without actual modification of the environment. Thanks to microbes, plants are now edible. We argue that the reciprocal niche construction of the host and its associated microbial organisms (i.e. the “holobiont”) scaffold each other’s developmental and phenotypic processes as well as organize a new selective environment of the holobiont as a whole

    Der praktische Brenner /

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    Zusammensetzung von Vor- und Nachlauffraktionen von Zwetschgenwasser

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    Data from: Transcriptome sequencing and microarray development for the woodrat (Neotoma spp.): custom genetic tools for exploring herbivore ecology

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    Massively parallel sequencing has enabled the creation of novel, in-depth genetic tools for nonmodel, ecologically important organisms. We present the de novo transcriptome sequencing, analysis and microarray development for a vertebrate herbivore, the woodrat (Neotoma spp.). This genus is of ecological and evolutionary interest, especially with respect to ingestion and hepatic metabolism of potentially toxic plant secondary compounds. We generated a liver transcriptome of the desert woodrat (Neotoma lepida) using the Roche 454 platform. The assembled contigs were well annotated using rodent references (99.7% annotation), and biotransformation function was reflected in the gene ontology. The transcriptome was used to develop a custom microarray (eArray, Agilent). We tested the microarray with three experiments: one across species with similar habitat (thus, dietary) niches, one across species with different habitat niches and one across populations within a species. The resulting one-colour arrays had high technical and biological quality. Probes designed from the woodrat transcriptome performed significantly better than functionally similar probes from the Norway rat (Rattus norvegicus). There were a multitude of expression differences across the woodrat treatments, many of which related to biotransformation processes and activities. The pattern and function of the differences indicate shared ecological pressures, and not merely phylogenetic distance, play an important role in shaping gene expression profiles of woodrat species and populations. The quality and functionality of the woodrat transcriptome and custom microarray suggest these tools will be valuable for expanding the scope of herbivore biology, as well as the exploration of conceptual topics in ecology
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