672 research outputs found

    Constitutive CD8 expression allows inefficient maturation of CD4+ helper T cells in class II major histocompatibility complex mutant mice.

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    Although mature CD4+ T cells bear T cell receptors (TCRs) that recognize class II major histocompatibility complex (MHC) and mature CD8+ T cells bear TCRs that recognize class I MHC, it is possible that the initial commitment of an immature thymocyte to a CD4 or CD8 lineage is made without regard to the specificity of the TCR. According to this model, CD4+ cells with class I TCR do not mature because the CD8 coreceptor is required for class I MHC recognition and positive selection. If this model is correct, constitutive expression of CD8 should allow CD4+ T cells with class I-specific TCRs to develop. In this report, we show that mature peripheral CD4+ cells are present in class II MHC-deficient mice that express a constitutive CD8.1 transgene. These cells share a number of properties with the major class II MHC-selected CD4 population, including the ability to express CD40 ligand upon activation. Although mature CD4 cells are also detectable in the thymus of class II MHC mutant/CD8.1 transgenic mice, they represent a small fraction of the mature CD4 cells found in mice that express class II MHC. These results indicate that some T cells choose the CD4 helper lineage independent of their antigen receptor specificity; however, the inefficiency of generating class I-specific CD4 cells leaves open the possibility that an instructive signal generated upon MHC recognition may bias lineage commitment

    Uneven progress in reducing exposure to violence at home for New Zealand adolescents 2001–2012: a nationally representative cross‐sectional survey series

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    Objective: To explore trends, and identify risk factors, that may explain changes in adolescent exposure to family violence over time.Methods: Data for this study was drawn from the Youth 2000 series of cross‐sectional surveys, carried out with New Zealand high school students in 2001, 2007 and 2012. Latent class analysis was used to understand different patterns of exposure to multiple risks for witnessing violence at home among adolescents.Results: Across all time periods, there was no change in witnessing emotional violence and a slight decline in witnessing physical violence at home. However, significant differences were noted between 2001 and 2007, and 2007 and 2012, in the proportion of adolescents who reported witnessing emotional and physical violence. Four latent classes were identified in the study sample; these were characterised by respondents' ethnicity, concerns about family relationships, food security and alcohol consumption. For two groups (characterised by food security, positive relationships and lower exposure to physical violence), there was a reduction in the proportion of respondents who witnessed physical violence but an increase in the proportion who witnessed emotional violence between 2001 and 2012. For the two groups characterised by poorer food security and higher exposure to physical violence, there were no changes in witnessing of physical violence in the home.Implications for public health: In addition to strategies directly aimed at violence, policies are needed to address key predictors of violence exposure such as social disparities, financial stress and alcohol use. These social determinants of health cannot be ignored

    A Study of Genetic Variability in Larval and Adult Populations of Dungeness Crab (Cancer Magister)

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    Spatial and temporal genetic variation was assessed using mitochondrial DNA from adult and megalopae of Dungeness crabs, Cancer magister, from Fraser Delta in British Columbia, Washington, Oregon, and California. Megalopae were continuously sampled using light traps in one location, Coos Bay, Oregon, and compared with adults sampled across the species\u27 range. While small-scale spatial and temporal variation were evident, there was no significant fit to the Isolation-by-Distance model when considering adult and larvae populations sampled over a coastal length of ~1700 km (Mantel r = 0.059, p = 0.289). Smaller bays showed higher genetic diversity than larger bays, contrary to typical expectations. MtDNA diversity measures (assessed by canonical correlation analysis) were correlated with bay size and depth, suggesting that hydrological patterns or fishing harvests in local areas (or a combination of both) influenced the observed genetic signature. The Dungeness crab ancestral population likely went through a historic population expansion associated with recent glacial relaxation, as evidenced by mismatch distributions and predominance of singleton haplotypes. In larval samples, we commonly observed numerous individuals of a haplotype, which suggests that families of larvae remain aggregated during dispersal. Sampled offspring revealed a low fraction of the adult gene pool (in accordance with the Hedgecock effect), yet high variability in recruitment over time. A realized long distance dispersal of larvae and the additive effects of recruitment from different sources over time may have prevented significant genetic differentiation within the C. magister range

    De-Identification of Work Zone Signage

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    In this session we compare methods used to alter the message displayed by construction signs either prior to or within a work zone. Various hinge techniques, sign covers, and secondary, qualifying signs are presently being used

    Environments in college home economics units as perceived by students

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    A magnetic film low frequency parametric amplifier

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    Resorts in Southern Appalachia: A Microcosm of American Resorts in the Nineteenth and Early Twentieth centuries.

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    Five resorts in East Tennessee--Montvale Springs and the Wonderland Hotel in the Smokies, Tate Spring in the Holston River Valley, Unaka Springs on the Nolichucky River, and the Cloudland Hotel at the summit of Roan Mountain--stand testament to the proposition that their region engaged fully with areas outside southern Appalachia. Their origins, clientele, and health and leisure offerings followed those of other resorts of the same time period. Moreover, the effects of national socioeconomic trends on the hotels serve as a contradiction to the stereotype of southern Appalachia as an isolated region barricaded from the outside world by mountainous topography. The East Tennessee resorts covered in this thesis indicate that the region as a whole was emblematic of national socioeconomic and cultural trends

    Characteristics and Potential Causes of Declining \u3ci\u3eDiporeia\u3c/i\u3e spp. Populations in Southern Lake Michigan and Saginaw Bay, Lake Huron

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    Populations of the amphipods Diporeia spp. are declining in all of the Great Lakes except Lake Superior. We examine characteristics and potential causes of declines in southern Lake Michigan and outer Saginaw Bay, Lake Huron. Amphipod populations began to decline within 3-4 years after zebra mussels (Dreissena polymorpha) colonized both areas. In Lake Michigan, which was better studied, the decline occurred first in shallow waters (\u3c30 m) and then progressed deeper (51-90 m). Between 1980- 1981 (pre-Dreissena) and 1998-1999 (post-Dreissena), densities at sites in these two depth intervals declined 92% and 58%, respectively. At a 45-m site in southeastern Lake Michigan, densities of Diporeia spp. declined to near zero within six months even though mussels were never collected at the site itself. At a nearby 45-m site, densities declined gradually to zero over a six-year period and correlated with increased mussel densities. Although mussels are likely outcompeting Diporeia spp. populations for food, and food limitation is probably a contributing factor to population declines, populations show no physiological signs of starvation; lipid content is at a maximum as densities approach zero. Pathogens, fish predation, contaminants, and low dissolved oxygen do not appear to be the sole causes of population declines. The decline of Diporeia spp. is likely to continue as dreissenid populations expand

    Characteristics and Potential Causes of Declining \u3ci\u3eDiporeia\u3c/i\u3e spp. Populations in Southern Lake Michigan and Saginaw Bay, Lake Huron

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    Populations of the amphipods Diporeia spp. are declining in all of the Great Lakes except Lake Superior. We examine characteristics and potential causes of declines in southern Lake Michigan and outer Saginaw Bay, Lake Huron. Amphipod populations began to decline within 3-4 years after zebra mussels (Dreissena polymorpha) colonized both areas. In Lake Michigan, which was better studied, the decline occurred first in shallow waters (\u3c30 m) and then progressed deeper (51-90 m). Between 1980- 1981 (pre-Dreissena) and 1998-1999 (post-Dreissena), densities at sites in these two depth intervals declined 92% and 58%, respectively. At a 45-m site in southeastern Lake Michigan, densities of Diporeia spp. declined to near zero within six months even though mussels were never collected at the site itself. At a nearby 45-m site, densities declined gradually to zero over a six-year period and correlated with increased mussel densities. Although mussels are likely outcompeting Diporeia spp. populations for food, and food limitation is probably a contributing factor to population declines, populations show no physiological signs of starvation; lipid content is at a maximum as densities approach zero. Pathogens, fish predation, contaminants, and low dissolved oxygen do not appear to be the sole causes of population declines. The decline of Diporeia spp. is likely to continue as dreissenid populations expand

    Campus Vol 1 N 3

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    Todd, George. The Valentine . Prose. 2. Fanslow, Ellen. Campus Canines . Prose. 3. Anonymous. Spring Glimpses on Campus . Picture. 4. Anonymous. Casual Corners . Prose. 6. Welch, Vera. Death is Not Sad . Poem. 7. Welch, Vera. I Do Not Love You . Poem. 7. Taylor, Louis. Clouds . Poem. 7. Dancy, Betty Jane. Pray Tell Me M\u27 Lord . Poem. 7. Dancy, Betty Jane. Really Our Friendship is Perfect . Poem. 7. Dancy, Betty Jane. You Say You Love Me For My Faith . Poem. 7. B.Z. The Mountain . Poem. 7. Findeisen, Robert. Do You Want to Be A Doctor? Cartoon. 8. Thomas, John C. Campus Kaleidoscope . Prose. 10. Harman, Betty. Sororities: The Way We See \u27Em . Prose. 12. Marshall, James. Dischargee . Poem. 14. Marshall, James. Suggestions to Dali . Poem. 14. Marshall, James. Sonnet Modern, In G Minor . Poem. 14. Marshall, James. The Request . Poem. 15. Dancy, Betty Jane. My Mother Always Bade Me Beware . Poem. 15. Anonymous. On the Cuff . Prose. 16
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