Expression of Ifnlr1 on intestinal epithelial cells is critical to the antiviral effects of IFN-lambda against norovirus and reovirus

Lambda interferon (IFN-λ) has potent antiviral effects against multiple enteric viral pathogens, including norovirus and rotavirus, in both preventing and curing infection. Because the intestine includes a diverse array of cell types, however, the cell(s) upon which IFN-λ acts to exert its antiviral effects is unclear. Here, we sought to identify IFN-λ-responsive cells by generation of mice with lineage-specific deletion of the receptor for IFN-λ, Ifnlr1. We found that expression of IFNLR1 on intestinal epithelial cells (IECs) in the small intestine and colon is required for enteric IFN-λ antiviral activity. IEC Ifnlr1 expression also determines the efficacy of IFN-λ in resolving persistent murine norovirus (MNoV) infection and regulates fecal shedding and viral titers in tissue. Thus, the expression of Ifnlr1 by IECs is necessary for the response to both endogenous and exogenous IFN-λ. We further demonstrate that IEC Ifnlr1 expression is required for the sterilizing innate immune effects of IFN-λ by extending these findings in Rag1-deficient mice. Finally, we assessed whether our findings pertained to multiple viral pathogens by infecting mice specifically lacking IEC Ifnlr1 expression with reovirus. These mice phenocopied Ifnlr1-null animals, exhibiting increased intestinal tissue titers and enhanced reovirus fecal shedding. Thus, IECs are the critical cell type responding to IFN-λ to control multiple enteric viruses. This is the first genetic evidence that supports an essential role for IECs in IFN-λ-mediated control of enteric viral infection, and these findings provide insight into the mechanism of IFN-λ-mediated antiviral activity. IMPORTANCE Human noroviruses (HNoVs) are the leading cause of epidemic gastroenteritis worldwide. Type III interferons (IFN-λ) control enteric viral infections in the gut and have been shown to cure mouse norovirus, a small-animal model for HNoVs. Using a genetic approach with conditional knockout mice, we identified IECs as the dominant IFN-λ-responsive cells in control of enteric virus infection in vivo. Upon murine norovirus or reovirus infection, Ifnlr1 depletion in IECs largely recapitulated the phenotype seen in Ifnlr1(−/−) mice of higher intestinal tissue viral titers and increased viral shedding in the stool. Moreover, IFN-λ-mediated sterilizing immunity against murine norovirus requires the capacity of IECs to respond to IFN-λ. These findings clarify the mechanism of action of this cytokine and emphasize the therapeutic potential of IFN-λ for treating mucosal viral infections

Soil insect control in reduced tillage cropping systems

"Missouri row crop producers have rapidly accepted and adopted reduced, conservation, or no-tillage practices. They planted about 55 percent or 6,000,000 acres of the 1981 crop of soybeans, corn, small grains, and grain sorghum in soils receiving some degree of reduced tillage. Although reduced tillage practices offer several advantages, one disadvantage is difficult insect control. Major insect problems occur more frequently and are often more damaging with reduced than with conventionally tilled crops."--First page.George W. Thomas, Armon J. Keaster and Judy A. Grundler (Department of Entomology, College of Agriculture)New 5/83/12

THE TYPE COLLECTION OF THE W. P. FRASER HERBARIUM (SASK) OF THE UNIVERSITY OF SASKATCHEWAN

With nearly 164000 specimens, the W. P.Fraser Herbarium (SASK) ranks among thetop 15 major herbaria in Canada. SASK isinvolved in the development of botanicalcollections, floristic inventories, taxonomic,systematic and biodiversity studies inSaskatchewan and specializes primarilyin the province’s native flora. In this paperan annotated list of the type specimens,scientific names, taxonomic authorities,protologue citations and collection data isprovided. Digital images of the typespecimens are available at:http://www.usask.ca/agriculture/plantsci/herbarium/types.shtml.La colección del herbario W. P. Fraser(SASK) de la Universidad de Saskatchewanse encuentra entre los 15 principalesherbarios de Canadá. A la fecha, lacolección del herbario contieneaproximadamente 164 000 ejemplares,incluyendo líquenes, plantas no vascularesy plantas vasculares. Uno de los objetivosprincipales de esta institución estáenfocado al desarrollo de las coleccionesbotánicas, inventarios florísticos, así comoestudios de biodiversidad y taxonómicosistemáticos con énfasis en la flora nativade la provincia de Saskatchewan. En esteartículo proporcionamos una lista detalladade los ejemplares tipo con el objeto dedifundir el importante acervo botánico a lacomunidad latinoamericana. Nuestra listaincluye nombres científicos, autoridadestaxonómicas, así como las citas bibliográficas originales en las cuales sepublicaron los nombres científicos, mismosque se encuentran en la biblioteca de SASK. Las imágenes digitales de los ejemplarestipo se encuentran disponibles en elherbario y en: http://www.usask.ca/agriculture/plantsci/herbarium/types.shtml.La colección tipo de SASK incluye dosejemplares tipos de líquenes y 45 ejemplaresde tipos de plantas vasculares. Con laexcepción de cuatro ejemplares tipo, el restode la colección tipo de SASK correspondea plantas nativas de Canadá. La lista deejemplares tipo está organizada alfabéticamente por familia y género, y a su vezdividida en los principales gruposvegetales, tal como: líquenes, pteridofitas,y antofitas (gimnospermas y angiospermas).El Herbario W. P. Fraser tiene dos objetivosprimarios: 1) contribuir al conocimiento dela biodiversidad y plantas raras de laprovincia de Saskatchewan y 2) proporcionar educación pública destinada alentendimiento tanto de la flora local comoregional, patrones de rareza, extirpación y extinción de especies vegetales, así comocrear conciencia del papel primordial de lascolecciones botánicas en educación yestudios de biodiversidad. La colección delherbario SASK contiene una grandiversidad de plantas representativas deCanadá. Aunque nos especializamos enflora de Saskatchewan, nuestra coleccióncuenta también con plantas representativasde las provincias de Alberta, Manitoba yNorthwest Territories. Nuestro herbario estáen vías de enriquecer la colección a nivelmundial y está en disposición de establecerintercambio de ejemplares de herbario coninstituciones interesadas en obtenerplantas de Canadá.En los dos últimos años, el herbario SASKha tenido varias modificaciones paramodernizar la infraestructura con elobjeto de implementar una coleccióndigital, así como una base de datos paradistribuir información botánica adistancia. Esta base de datos está basadaen el programa Specify4. Asimismo, elsitio de Internet de SASK incluyeinformación valiosa con respecto a labiodiversidad vegetal de Saskatchewan.En este sitio se encuentran disponibleslistas florísticas de plantas nativas rarasa nivel provincial y nacional. Nuestro sitiocontiene además claves interactivas parala identificación de especies de lasfamilias de plantas vasculares deSaskatchewan. Asimismo, nuestro sitiode Internet cuenta con detalladas clavespara la identificación de las cactáceas dela provincia. Estas claves son muy útilespara los cursos de botánica que se imparten en nuestra institución.Finalmente, a finales de 2003, nuestro sitode Internet lanzó el Herbario Virtual, cuyo objetivo es establecer puentes educativosa distancia entre la Universidad deSaskatchewan y el público que no tienecapacidad de asistir a la Universidad. Engeneral, el Herbario Virtual hace que elmaterial esté al alcance del mundo, y seespera que la colección entera se encuentredisponible en el Internet a finales de 2005

Control of wireworms and other corn soil insects

"This guide recommends management practices and insecticides for reduction of the following corn soil insect pest problems: wireworrns, white grubs and annual grubs, billbugs, sod webworrns, seed damaging insects, bird and rodent damage to seed and seedlings and insect pest control in no-tillage sod plantings."--First page.George W Thomas, Armon J. Keaster, and Judy A Grundler (Department of Entomology College of Agriculture)Revised 1/83/7.5

Solar proton effects on austral ozone during the final months of 1989

Intense solar activity during 1989 prompted six major particle events. Four of these occurred between August and December. Energetic solar protons are a natural source of ozone depletion due to the nitric oxides they produce in the polar atmospheres. In particular, modelling (Reid et al., 1991) of an event that peaked on October 20 (with greater than 10 MeV proton flux of 73000 particles sq cm s(exp -1) ster(exp -1) yields 55 percent column density enhancements of NO over the southern polar cap. Total column ozone data from the total ozone ,mapping spectrometer (TOMS) instrument aboard the Nimbus 7 satellite used at times when solar illumination facilitates measurements by TOMS over the entire southern polar regions. The impact of odd nitrogen enhancements on the spatial extent of low total column ozone and of the total ozone mass, over a region August to December. Comparisons are made with previous years (1984 to 1988) of moderate solar activity. The effect, if any, of these events on ozone during times of heterogeneous chlorine chemistry and dynamic processes is discussed

Corn cutworm control for 1983

"This guide recommends management practices and insecticides for reduction of injury caused by the various cutworms attacking com in Missouri. It also discusses the life cycles of the more common species which feed at and below ground and those species which are primarily above ground foliage feeders."--First page.George W. Thomas, Armon J. Keasler, Richard N. Story and Judy A. Grundler (Department of Entomology, College of Agriculture)Revised 2/83/8

A perpetual switching system in pulmonary capillaries

Of the 300 billion capillaries in the human lung, a small fraction meet normal oxygen requirements at rest, with the remainder forming a large reserve. The maximum oxygen demands of the acute stress response require that the reserve capillaries are rapidly recruited. To remain primed for emergencies, the normal cardiac output must be parceled throughout the capillary bed to maintain low opening pressures. The flow-distributing system requires complex switching. Because the pulmonary microcirculation contains contractile machinery, one hypothesis posits an active switching system. The opposing hypothesis is based on passive switching that requires no regulation. Both hypotheses were tested ex vivo in canine lung lobes. The lobes were perfused first with autologous blood, and capillary switching patterns were recorded by videomicroscopy. Next, the vasculature of the lobes was saline flushed, fixed by glutaraldehyde perfusion, flushed again, and then reperfused with the original, unfixed blood. Flow patterns through the same capillaries were recorded again. The 16-min-long videos were divided into 4-s increments. Each capillary segment was recorded as being perfused if at least one red blood cell crossed the entire segment. Otherwise it was recorded as unperfused. These binary measurements were made manually for each segment during every 4 s throughout the 16-min recordings of the fresh and fixed capillaries (>60,000 measurements). Unexpectedly, the switching patterns did not change after fixation. We conclude that the pulmonary capillaries can remain primed for emergencies without requiring regulation: no detectors, no feedback loops, and no effectors-a rare system in biology. NEW & NOTEWORTHY The fluctuating flow patterns of red blood cells within the pulmonary capillary networks have been assumed to be actively controlled within the pulmonary microcirculation. Here we show that the capillary flow switching patterns in the same network are the same whether the lungs are fresh or fixed. This unexpected observation can be successfully explained by a new model of pulmonary capillary flow based on chaos theory and fractal mathematics