Comparison and Contrast of Perceptions of Current and Ideal Levels of Involvement with Tasks Performed by School Library Media Supervisors

Comparison and contrast of perceptions of current and ideal levels of Involvement with 50 tasks by 45 district level school library media supervisors in Texas public schools was accomplished using a survey instrument eliciting information in three areas: Curriculum and Instruction, Public Relations and Communication, Actainistration and Budget. Using tasks based on a Texas Education Agency publication, i, tests for correlated means were used to determine statistically significant differences between means for current and ideal levels of involvement for supervisors grouped by age, degree and certification as well as for the group as a whole. Findings showed that most demographic groupings perceived a need for greater involvement with various curriculum planning and design activities, evaluation of noncertlficated library media personnel and with various public relations activities

Warming Reduces Tall Fescue Abundance but Stimulates Toxic Alkaloid Concentrations in Transition Zone Pastures of the U.S.

Tall fescue pastures cover extensive acreage in the eastern half of the United States and contribute to important ecosystem services, including the provisioning of forage for grazing livestock. Yet little is known concerning how these pastures will respond to climate change. Tall fescue\u27s ability to persist and provide forage under a warmer and wetter environment, as is predicted for much of this region as a result of climate change, will likely depend on a symbiotic relationship the plant can form with the fungal endophyte, Epichloë coenophiala. While this symbiosis can confer environmental stress tolerance to the plant, the endophyte also produces alkaloids toxic to insects (e.g., lolines) and mammals (ergots; which can cause fescue toxicosis in grazing animals). The negative animal health and economic consequences of fescue toxicosis make understanding the response of the tall fescue symbiosis to climate change critical for the region. We experimentally increased temperature (+3°C) and growing season precipitation (+30% of the long-term mean) from 2009-2013 in a mixed species pasture, that included a tall fescue population that was 40% endophyte-infected. Warming reduced the relative abundance of tall fescue within the plant community, and additional precipitation did not ameliorate this effect. Warming did not alter the incidence of endophyte infection within the tall fescue population; however, warming significantly increased concentrations of ergot alkaloids (by 30-40%) in fall-harvested endophyte-infected individuals. Warming alone did not affect loline alkaloid concentrations, but when combined with additional precipitation, levels increased in fall-harvested material. Although future warming may reduce the dominance of tall fescue in eastern U.S. pastures and have limited effect on the incidence of endophyte infection, persisting endophyte-infected tall fescue will have higher concentrations of toxic alkaloids which may exacerbate fescue toxicosis

Alkaloid quantities in endophyte-infected tall fescue are affected by the plant-fungus combination and environment

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YUKON MOOSE: I. SEASONAL RESOURCE SELECTION BY MALES AND FEMALES IN A MULTI-PREDATOR BOREAL ECOSYSTEM

Moose (Alces alces) in Yukon experience an extreme range of thermal conditions, highly variable snow depths, natural and anthropogenic disturbances, predation by wolves and grizzly bears, and hunting pressure. Our objective was to identify variables that best explained habitat-selection patterns of moose in south-central Yukon for use in land-use planning and impact assessment. We evaluated selection of land-cover class, elevation, aspect, predation risk, and harvest vulnerability using resource selection functions. We created pooled models for males and females by averaging models for individuals by sex and season. Selection of shrub-dominated land cover highlighted the importance of forage accessibility throughout the year. Selection for elevation, aspect, and cover changed throughout the year, as influenced by climatic conditions. By selecting mixed cover types during calving and summer, female moose presumably balanced needs for both cover and forage. Males minimized harvest vulnerability during rut. Moose, in general, demonstrated highly variable habitat selection; however, consistent individual responses between sexes supported trends identified by pooled selection coefficients, as well as detected trends among males and females. The greatest amount of individual variation occurred during the growing season and the least amount during late winter, suggesting that climatic factors limited the options available to moose at a critical time of the year

YUKON MOOSE: II. RANGE SIZES, MOVEMENT RATES, AND USE OF ELEVATION AND LAND COVER BY MALES AND FEMALES

Moose (Alces alces), as a focal species in many northern communities, are increasingly subjected to anthropogenic activities. We studied range use by moose (males and females with and without calves) to enable more effective land-use planning in south-central Yukon. We detected seasonal differences in range sizes, movement rates, and use of elevation and land cover by global positioning system (GPS)-collared individuals, reflecting the responses of individuals to changing resource availability that is characteristic of boreal landscapes. During winter, moose in the South Canol area generally used smaller ranges at lower elevations and moved at lower rates within them, presumably limited by snow depths. They moved up in elevation throughout summer, reaching maximum elevations during rut and early winter. Moose used conifer stands, which were prevalent on the landscape, more than any other land-cover class throughout the year. Their use of upland and lowland shrub classes varied with season, with highest combined use of shrub-dominated land cover in early and late winter, likely reflecting the importance of shrubs as winter forage. We were unable to identify significant differences between the sexes or relative to reproductive status (i.e., calf presence). Differences between these groups in meeting requirements for forage and cover may be more discrete at the finer scale of microsite characteristics

The effect of polar lipids on tear film dynamics

In this paper we present a mathematical model describing the effect of polar lipids on the evolution of a precorneal tear film, with the aim of explaining the interesting experimentally observed phenomenon that the tear film continues to move upwards even after the upper eyelid has become stationary. The polar lipid is an insoluble surface species that locally alters the surface tension of the tear film. In the lubrication limit, the model reduces to two coupled nonlinear partial differential equations for the film thickness and the concentration of lipid. We solve the system numerically and observe that the presence of the lipid causes an increase in flow of liquid up the eye. We further exploit the size of the parameters in the problem to explain the initial evolution of the system

Advances in ophthalmic drug delivery

Various strategies for ocular drug delivery are considered; from basic formulation techniques for improving availability of drugs; viscosity enhancers and mucoadhesives aid drug retention and penetration enhancers promote drug transport into the eye. The use of drug loaded contact lenses and ocular inserts allows drugs to be better placed where they are needed for more direct delivery. Developments in ocular implants gives a means to overcome the physical barriers that traditionally prevented effective treatment. Implant technologies are under development allowing long term drug delivery from a single procedure, these devices allow posterior chamber diseases to be effectively treated. Future developments could bring artificial corneas to eliminate the need for donor tissue and one-off implantable drug depots lasting the patient’s lifetime

Herbivory and eutrophication mediate grassland plant nutrient responses across a global climatic gradient

Plant stoichiometry, the relative concentration of elements, is a key regulator of ecosystem functioning and is also being altered by human activities. In this paper we sought to understand the global drivers of plant stoichiometry and compare the relative contribution of climatic vs. anthropogenic effects. We addressed this goal by measuring plant elemental (C, N, P and K) responses to eutrophication and vertebrate herbivore exclusion at eighteen sites on six continents. Across sites, climate and atmospheric N deposition emerged as strong predictors of plot‐level tissue nutrients, mediated by biomass and plant chemistry. Within sites, fertilization increased total plant nutrient pools, but results were contingent on soil fertility and the proportion of grass biomass relative to other functional types. Total plant nutrient pools diverged strongly in response to herbivore exclusion when fertilized; responses were largest in ungrazed plots at low rainfall, whereas herbivore grazing dampened the plant community nutrient responses to fertilization. Our study highlights (1) the importance of climate in determining plant nutrient concentrations mediated through effects on plant biomass, (2) that eutrophication affects grassland nutrient pools via both soil and atmospheric pathways and (3) that interactions among soils, herbivores and eutrophication drive plant nutrient responses at small scales, especially at water‐limited sites