Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
Articles 1 - 9 of 9
Full-Text Articles in Life Sciences
Uv-B Screening Potential Is Higher In Two Cosmopolitan Moss Species Than In A Co-Occurring Antarctic Endemic Moss – Implications Of Continuing Ozone Depletion, J. L. Dunn, Sharon A. Robinson
Uv-B Screening Potential Is Higher In Two Cosmopolitan Moss Species Than In A Co-Occurring Antarctic Endemic Moss – Implications Of Continuing Ozone Depletion, J. L. Dunn, Sharon A. Robinson
Faculty of Science - Papers (Archive)
Concentrations of UV-B absorbing pigments and anthocyanins were measured in three moss species, over a summer growing season in Antarctica. Pigment concentrations were compared with a range of climatic variables to determine if there was evidence that pigments were induced by UV-B radiation, or other environmental parameters, and secondly if there were differences between species in their pigment responses. Significant seasonal differences in the potential UV-B screening pigments were found, with the two cosmopolitan species Bryum pseudotriquetrum and Ceratodon purpureus appearing better protected from the potentially damaging effects of ozone depletion than the Antarctic endemic Schistidium antarctici. Bryum pseudotriquetrum accumulated …
A Sex-Linked Allele, Autosomal Modifiers And Temperature-Dependence Appear To Regulate Melanism In Male Mosquitofish (Gambusia Holbrooki), Lisa Horth
Biological Sciences Faculty Publications
About 1% of male mosquitofish (Gambusia holbrooki) express melanic (mottled-black) body coloration, which differs dramatically from the wild-type, silvery-gray coloration. Here, I report on the genetic inheritance pattern of melanic coloration, which indicates Y-linkage, and at least one autosomal modifier. Phenotypic expression of melanism is also affected by temperature. Expression is constitutive ( temperature insensitive) in some populations, inducible ( temperature sensitive) in others. Constitutive and inducible expression occur among geographically proximal populations. However, males from any single population demonstrate the same constitutive or inducible expression pattern as one another. The F1 males from inter-population crosses demonstrate temperature-related …
Laboratory Environment Effects On The Reproduction And Mortality Of Adult Screwworm (Diptera: Calliphoridae), Dennis Berkebile, Agustin Sagel, Steven R. Skoda, John E. Foster
Laboratory Environment Effects On The Reproduction And Mortality Of Adult Screwworm (Diptera: Calliphoridae), Dennis Berkebile, Agustin Sagel, Steven R. Skoda, John E. Foster
Department of Entomology: Faculty Publications
The New World screwworm, Cochliomyia hominivorax Coquerel, is mass reared for screwworm eradication initiatives that use the sterile insect technique. New methods for rearing have helped to reduce the cost of the eradication program. We examined the effect and interaction of three temperatures (24.5, 29.5 and 34.5ºC), two diets (2% spray-dried blood plus 0.05% vitamins and corn syrup carrageenan) and three population densities (300, 400, and 500 flies/cage) on egg production, egg hatch, number of observable fertilized eggs, mortality (male and female) and ovarian development. The three population densities did not affect any of the parameters monitored. Using the protein …
Circadian Rhythmicity By Autocatalysis, Arun Mehra, Christian I. Hong, Mi Shi, Jennifer J. Loros, Jay C. Dunlap, Peter Ruoff
Circadian Rhythmicity By Autocatalysis, Arun Mehra, Christian I. Hong, Mi Shi, Jennifer J. Loros, Jay C. Dunlap, Peter Ruoff
Dartmouth Scholarship
The temperature compensated in vitro oscillation of cyanobacterial KaiC phosphorylation, the first example of a thermodynamically closed system showing circadian rhythmicity, only involves the three Kai proteins (KaiA, KaiB, and KaiC) and ATP. In this paper, we describe a model in which the KaiA- and KaiB-assisted autocatalytic phosphorylation and dephosphorylation of KaiC are the source for circadian rhythmicity. This model, based upon autocatalysis instead of transcription-translation negative feedback, shows temperature-compensated circadian limit-cycle oscillations with KaiC phosphorylation profiles and has period lengths and rate constant values that are consistent with experimental observations.
Microbial Decomposition Of Skeletal Muscle Tissue (Ovis Aries) In A Sandy Loam Soil At Different Temperatures, David O. Carter, Mark Tibbett
Microbial Decomposition Of Skeletal Muscle Tissue (Ovis Aries) In A Sandy Loam Soil At Different Temperatures, David O. Carter, Mark Tibbett
Department of Entomology: Faculty Publications
A laboratory experiment was conducted to determine the effect of temperature (2, 12, 22 °C) on the rate of aerobic decomposition of skeletal muscle tissue (Ovis aries) in a sandy loam soil incubated for a period of 42 days. Measurements of decomposition processes included skeletal muscle tissue mass loss, carbon dioxide (CO2) evolution, microbial biomass, soil pH, skeletal muscle tissue carbon (C) and nitrogen (N) content and the calculation of metabolic quotient (qCO2). Incubation temperature and skeletal muscle tissue quality had a significant effect on all of the measured process rates with 2 °C …
Increasing Co2 From Subambient To Elevated Concentrations Increases Grassland Respiration Per Unit Of Net Carbon Fixation, H. Wayne Polley, Patricia C. Meilnick, William A. Dugas, Hyrum B. Johnson, Joaquin Sanabria
Increasing Co2 From Subambient To Elevated Concentrations Increases Grassland Respiration Per Unit Of Net Carbon Fixation, H. Wayne Polley, Patricia C. Meilnick, William A. Dugas, Hyrum B. Johnson, Joaquin Sanabria
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Respiration (carbon efflux) by terrestrial ecosystems is a major component of the global carbon (C) cycle, but the response of C efflux to atmospheric CO2 enrichment remains uncertain. Respiration may respond directly to an increase in the availability of C substrates at high CO2, but also may be affected indirectly by a CO2-mediated alteration in the amount by which respiration changes per unit of change in temperature or C uptake (sensitivity of respiration to temperature or C uptake).
Temperature Effects On Bradyrhizobium Spp. Growth And Symbiotic Effectiveness With Pigeonpea And Cowpea, Lurline E. Marsh, Raymond Baptiste, Dyremple B. Marsh, David Trinklein, Robert J. Kremer
Temperature Effects On Bradyrhizobium Spp. Growth And Symbiotic Effectiveness With Pigeonpea And Cowpea, Lurline E. Marsh, Raymond Baptiste, Dyremple B. Marsh, David Trinklein, Robert J. Kremer
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Temperature is a limiting factor on legume-Bradyrhizobium symbiosis of subtropical plants in the temperate region. Twelve strains of Bradyrhizobium spp. that nodulate pigeonpea [Cajanus cajan (L.) Millsp], and cowpea [Vigna unguiculata (L.) Walp], were evaluated for tolerance to three temperature regimes (20 °C/10 °C, 30 °C/20 °C, and 38 °C/25 °C day/night temperature) by determining their growth following exposure to the regimes. The five most temperature-tolerant strains were further evaluated for symbiotic effectiveness with pigeonpea and cowpea under controlled temperatures. These strains were USDA 3278, USDA 3362, USDA 3364, USDA 3458, and USDA 3472. Plant heights of …
Challenges To Temperature Regulation When Working In Hot Environments, Nigel Taylor
Challenges To Temperature Regulation When Working In Hot Environments, Nigel Taylor
Faculty of Health and Behavioural Sciences - Papers (Archive)
The focus of this revuew us upon acute exposure to hot environments and the accompanying physiological changes. The target audience includes physiologists, physicians and occupational health and safety practioners. Using the principles of thermodynamics, the avenues for human heat exchange and explored, leading to an evaluation of some methods used to assess thermally-stressful environments. In particular, there is a critique of the wet-bulb globe temperature (WBGT) index, and an overview of an alternative means by which such assessments may be undertaken (the heat stress index). These principles and methods are combined to illustrate how one may evaluate the risk of …
Effects Of Substrate And Temperature On Growth Of Aspergillus Flavus In Peanuts From Georgia, Premila Achar, Andres Sachez
Effects Of Substrate And Temperature On Growth Of Aspergillus Flavus In Peanuts From Georgia, Premila Achar, Andres Sachez
Faculty Articles
We investigated the effects of different substrates (potato dextrose agar [PDA], nutrient agar [NA], and corn meal agar [CMA]) and temperatures on growth and aflatoxin production in Aspergillus flavus. Contaminated peanuts from retailers at different locations in Georgia were used throughout the experiment and 200 seeds were selected from each sample. PDA, NA, and CMA served as the substrate to express the mold from the contaminated seeds. Seeds were plated equidistantly on each of the media and incubated at 10° C, 27° C, 30° C, and 37° C, respectively. Seeds incubated on moist filter paper served as control. Neither growth …