Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 25 of 25

Full-Text Articles in Life Sciences

Heat-Shock Protein 70 (Hsp70) As A Biochemical Stress Indicator: An Experimental Field Test In Two Congeneric Intertidal Gastropods (Genus: Tegula), Lars Tomanek, Eric Sanford Dec 2003

Heat-Shock Protein 70 (Hsp70) As A Biochemical Stress Indicator: An Experimental Field Test In Two Congeneric Intertidal Gastropods (Genus: Tegula), Lars Tomanek, Eric Sanford

Biological Sciences

Although previous studies have demonstrated that heat-shock protein 70 (Hsp70) can be induced by environmental stress, little is known about natural variation in this response over short time scales. We examined how Hsp70 levels varied over days to weeks in two intertidal snail species of the genus Tegula. Sampling was conducted both under naturally changing environmental conditions and in different vertical zones on a rocky shore. The subtidal to low-intertidal T. brunnea was transplanted into shaded and unshaded mid-intertidal cages to assess temporal variation in Hsps under conditions of increased stress. For comparison, the low to mid-intertidal ,T. funebralis was ...


Continuous Hyperspectral Absorption Measurements Of Colored Dissolved Organic Material In Aquatic Systems, Gary J. Kirkpatrick, Cristina Orrico, Mark A. Moline, Matthew Oliver, Oscar M. Schofield Nov 2003

Continuous Hyperspectral Absorption Measurements Of Colored Dissolved Organic Material In Aquatic Systems, Gary J. Kirkpatrick, Cristina Orrico, Mark A. Moline, Matthew Oliver, Oscar M. Schofield

Biological Sciences

The majority of organic carbon in the oceans is present as dissolved organic matter (DOM); therefore understanding the distribution and dynamics of DOM is central to understanding global carbon cycles. Describing the time-space variability in colored dissolved organic matter (CDOM) has been difficult, as standard spectrophotometric methods for CDOM determination are laborious and susceptible to methodological biases. Previously, measurements of CDOM absorption in discrete water samples by use of a liquid-waveguide capillary cell (LWCC) compared favorably with measurements made with a benchtop spectrophotometer. Given this, we focused on automating the LWCC technique to improve our spatial and temporal sampling capabilities ...


Analysis Of Platelet Activating Factor In The Gravid Reproductive Tracts Of Swine, William E. Plummer Nov 2003

Analysis Of Platelet Activating Factor In The Gravid Reproductive Tracts Of Swine, William E. Plummer

Animal Science

Depressed hog prices in 1998 and 1999 were due to not enough shackle space (kill capacity) and not to a glut of slaughter swine. However, many swine producers were put out of business in California. In 2000, market prices rebounded due to increased shackle space and reduced numbers of slaughter swine available as a result of the sellouts of the previous two years. The economic roller coaster ride emphasized the need for maximizing profit while streamlining operations. Increasing numbers of pigs per litter, and thereby reducing the cost per pig produced, is one aspect of streamlining. A significant step in ...


Complex Co-Substrate Addition Increases Initial Petroleum Degradation Rates During Land Treatment By Altering Bacterial Community Physiology, Christopher W, Kaplan, Brian G. Clement, Alice Hamrick, Robert W. Pease, Carl Flint, Raul J. Cano, Christopher L. Kits Oct 2003

Complex Co-Substrate Addition Increases Initial Petroleum Degradation Rates During Land Treatment By Altering Bacterial Community Physiology, Christopher W, Kaplan, Brian G. Clement, Alice Hamrick, Robert W. Pease, Carl Flint, Raul J. Cano, Christopher L. Kits

Biological Sciences

A pilot-scale land treatment unit (LTU) was constructed at the former Guadalupe oil production field with the purpose of investigating the effect of co-substrate addition on the bacterial community and the resulting rate and extent of total petroleum hydrocarbon (TPH) degradation. The TPH was a weathered mid-cut distillate (C10-C32) excavated from the subsurface and stockpiled before treatment. A control cell (Cell 1) in the LTU was amended with nitrogen and phosphorus while the experimental cell (Cell 2) was amended with additional complex co-substrate—corn steep liquor. During the pilot LTU operation, measurements were taken of TPH, nutrients, moisture, aerobic heterotrophic ...


Chromosome-Wide Control Of Meiotic Crossing Over In C. Elegans, Kenneth J. Hillers, Anne M. Villeneuve Sep 2003

Chromosome-Wide Control Of Meiotic Crossing Over In C. Elegans, Kenneth J. Hillers, Anne M. Villeneuve

Biological Sciences

A central event in sexual reproduction is the reduction in chromosome number that occurs at the meiosis I division. Most eukaryotes rely on crossing over between homologs, and the resulting chiasmata, to direct meiosis I chromosome segregation, yet make very few crossovers per chromosome pair [1] and [2]. This indicates that meiotic recombination must be tightly regulated to ensure that each chromosome pair enjoys the crossover necessary to ensure correct segregation. Here, we investigate control of meiotic crossing over in Caenorhabditis elegans, which averages only one crossover per chromosome pair per meiosis [3] and [4], by constructing genetic maps of ...


Characterization Of Six Polymorphic Microsatellites For The Polychaete Tubeworm Hydroides Elegans And Cross-Species Amplification In The Congener Hydroides Hexagonus, J. B. Pettengill, M. G. Hadfield, M. D. Schug, D. E. Wendt Sep 2003

Characterization Of Six Polymorphic Microsatellites For The Polychaete Tubeworm Hydroides Elegans And Cross-Species Amplification In The Congener Hydroides Hexagonus, J. B. Pettengill, M. G. Hadfield, M. D. Schug, D. E. Wendt

Biological Sciences

We isolated and characterized six polymorphic microsatellite loci for the polychaete tubeworm, Hydroides elegans. Two additional loci were not reliably scorable and estimates of heterozygosity were obtained for the other six. In addition, cross-species amplification was successful for two loci using the congener H. hexagonus. Given that few microsatellite loci are available for polychaetes, these markers will be useful in assessing dispersal and gene flow in H. elegans and probably also other polychaetes.


Phenotype Management: A New Approach To Habitat Restoration, Jason V. Watters, Sean C. Lema, Gabrielle A. Nevitt Aug 2003

Phenotype Management: A New Approach To Habitat Restoration, Jason V. Watters, Sean C. Lema, Gabrielle A. Nevitt

Biological Sciences

The goal of habitat restoration is to provide environmental conditions that promote the maintenance and growth of target populations. But rarely is it considered how the allocation of resources influences the diversity of phenotypes in these populations. Here we present a framework for considering how habitat restoration can shape the development and expression of phenotypes. We call this approach phenotype management as it entails restoring the resources in a habitat to manage phenotypic diversity. Phenotype management is achieved by manipulating the spatial and temporal distribution of resources to alter the degree of competition among individuals. Differences in competition, in turn ...


Functional And Comparative Genomic Analyses Of An Operon Involved In Fructooligosaccharide Utilization By Lactobacillus Acidophilus, Rodolphe Barrangou, Eric Altermann, Robert Hutkins, Raul J. Cano, Todd Klaenhammer Jul 2003

Functional And Comparative Genomic Analyses Of An Operon Involved In Fructooligosaccharide Utilization By Lactobacillus Acidophilus, Rodolphe Barrangou, Eric Altermann, Robert Hutkins, Raul J. Cano, Todd Klaenhammer

Biological Sciences

Lactobacillus acidophilus is a probiotic organism that displays the ability to use prebiotic compounds such as fructooligosaccharides (FOS), which stimulate the growth of beneficial commensals in the gastrointestinal tract. However, little is known about the mechanisms and genes involved in FOS utilization by Lactobacillus species. Analysis of the L. acidophilus NCFM genome revealed an msm locus composed of a transcriptional regulator of the LacI family, a four-component ATP-binding cassette (ABC) transport system, a fructosidase, and a sucrose phosphorylase. Transcriptional analysis of this operon demonstrated that gene expression was induced by sucrose and FOS but not by glucose or fructose ...


Variation Between Observed And True Terminal Restriction Fragment Length Is Dependent On True Trf Length And Purine Content, Christopher W. Kaplan, Christopher L. Kitts Jul 2003

Variation Between Observed And True Terminal Restriction Fragment Length Is Dependent On True Trf Length And Purine Content, Christopher W. Kaplan, Christopher L. Kitts

Biological Sciences

Terminal Restriction Fragment (TRF) pattern analysis has become a widely used and informative tool for studying microbial communities. Variation between sequence-determined or true TRF length and observed TRF length (TRF drift) has been previously reported and can significantly affect identification of bacterial species using TRF lengths predicted from sequence databases. In this study TRF drift was determined for 21 bacterial species using an ABI 310 Genetic Analyzer. TRF drift was positively correlated with true TRF length and negatively correlated with TRF purine content. This implies that subtle differences in molecular weight, whether from purine content or dye label, can significantly ...


Spider And Leafhopper (Erythroneura Spp.) Response To Vineyard Ground Cover, Michael J. Costello, Kent M. Daane Jul 2003

Spider And Leafhopper (Erythroneura Spp.) Response To Vineyard Ground Cover, Michael J. Costello, Kent M. Daane

Horticulture and Crop Science

Ground cover is used in some vineyards to improve soil structure and help manage insect pests; previous studies have shown lower leafhopper (Erythroneura spp.) densities on vines grown with ground cover. We undertook a 2-yr study to determine why ground cover is associated with reduced leafhopper densities. Ground cover consisted of a fall-planted cover crop of purple vetch (Vicia benghalensis) and barley (Hordeum vulgare), which senesced in May and was replaced by a complex of resident vegetation comprised primarily of the grasses Echinochloa spp., Digitaria sanguinalis, and Setaria spp., as well as common knotweed (Polygonum aviculare). We compared three treatments ...


Determination Of The Sensory Attributes Of Dried Milk Powders And Dairy Ingredients, M. A. Drake, Y. Karagul-Yuceer, K. R. Cadwallader, G. V. Civille, P. S. Tong Jul 2003

Determination Of The Sensory Attributes Of Dried Milk Powders And Dairy Ingredients, M. A. Drake, Y. Karagul-Yuceer, K. R. Cadwallader, G. V. Civille, P. S. Tong

Dairy Science

A standardized descriptive language for skim milk powder and dried dairy ingredients was developed. The lexicon was initially identified from a large sample set of dried dairy ingredients (138). A highly trained descriptive panel (n = 14) refined terms and identified references. Dried dairy ingredients (36) were then evaluated using the developed language. Twenty-one descriptors were identified for dried dairy ingredients. Seventeen flavors and tastes were identified in skim milk powders (27) with nine flavors/tastes observed in all skim milk powders. Dried dairy ingredients were differentiated using the language (P


A Pcr Assay For Specific Detection Of The Pandemic Vibrio Parahaemolyticus O3:K6 Clone From Shellfish, P.S. Marie Yeung, A. Depaola, C. A. Kaysner, K. J. Boor May 2003

A Pcr Assay For Specific Detection Of The Pandemic Vibrio Parahaemolyticus O3:K6 Clone From Shellfish, P.S. Marie Yeung, A. Depaola, C. A. Kaysner, K. J. Boor

Biological Sciences

The current standard method for identifying Vibrio parahaemolyticus serotype O3:K6, an emerging pathogen with apparent enhanced virulence characteristics, typically takes 4 to 6 d to complete and requires serotyping. To provide a more rapid strategy, we optimized a polymerase chain reaction (PCR)-based assay for specific detection of V. parahaemolyticus O3:K6. Of 78 V. parahaemolyticus isolates and other related species; only strains classified into the V. parahaemolyticus O3:K6 clonal group (n = 39) showed positive results in the PCR assay. The assay detected 2.3 cells/PCR reaction and 310 cells/g using bacterial cultures and inoculated oyster ...


Preparation Of 2s,3s-N-Isobutyl-N-(2-Hydroxy-3-Amino-4-Phenylbutyl)-P-Nitrobenzenesulfonylamide Hydrochloride And Other Derivatives Of 2-Hydroxy-1,3-Diamines, Aslam A. Malik, Hasan Palandoken, Joy A. Stringer, Roland P. Carlson, John Leach, Thomas G. Archibald, Robert G. Miotke Apr 2003

Preparation Of 2s,3s-N-Isobutyl-N-(2-Hydroxy-3-Amino-4-Phenylbutyl)-P-Nitrobenzenesulfonylamide Hydrochloride And Other Derivatives Of 2-Hydroxy-1,3-Diamines, Aslam A. Malik, Hasan Palandoken, Joy A. Stringer, Roland P. Carlson, John Leach, Thomas G. Archibald, Robert G. Miotke

Chemistry and Biochemistry

The present invention provides a new process for the preparation of 2S,3S-N-isobutyl-N-(2-hydroxy-3-amino-4phenylbutyl)- p-nitrobenzenesulfonylamide hydrochloride, wherein this compound is prepared directly from the chloromethylalcohol. Importantly, the process of the present invention results in higher yields of 2S,3S-N-isobutyl-N-(2hydroxy -3 -amino -4-phenylbutyl) -pnitrobenzenesulfonylamide hydrochloride without sacrificing its purity. The processes of the present inventin can be used to prepare not only the 2S,3S-derivative, but also the 2R,3S-, 2S,2R- and the 2R,3R-derivatives.


Clean, High-Yield Preparation Of S,S- And R,S- Amino Acid Isosteres, Aslam A. Malik, Todd E. Clement, Hasan Palandoken, James Robinson Iii, Joy A. Stringer Apr 2003

Clean, High-Yield Preparation Of S,S- And R,S- Amino Acid Isosteres, Aslam A. Malik, Todd E. Clement, Hasan Palandoken, James Robinson Iii, Joy A. Stringer

Chemistry and Biochemistry

The present invention provides compounds and methods that can be used to convert the intermediate halomethyl ketones (HMKs), e.g., chloromethyl ketones, to the corresponding S,S- and R,S-diastereomers. More particularly, the present invention provides: (1) reduction methods; (2) inversion methods; and (3) methods involving the epoxidation of alkenes. Using the various methods of the present invention, the R,S-epoxide and the intermediary compounds can be prepared reliably, in high yields and in high purity.


Structure-Property Relationships Of Silicone Biofouling-Release Coatings: Effect Of Silicone Network Architecture On Pseudobarnacle Attachment Strengths, Judith Stein, Kathryn Truby, Christina Darkangelo Wood, Michael Takemori, Michael Vallance, Geoffrey Swain, Christopher Kavanagh, Brett Kovach, Michael Schultz, Deborah Wiebe, Eric Holm, Jean Montemarano, Dean Wendt, Celia Smith, Anne Meyer Apr 2003

Structure-Property Relationships Of Silicone Biofouling-Release Coatings: Effect Of Silicone Network Architecture On Pseudobarnacle Attachment Strengths, Judith Stein, Kathryn Truby, Christina Darkangelo Wood, Michael Takemori, Michael Vallance, Geoffrey Swain, Christopher Kavanagh, Brett Kovach, Michael Schultz, Deborah Wiebe, Eric Holm, Jean Montemarano, Dean Wendt, Celia Smith, Anne Meyer

Biological Sciences

Model silicone foul-release coatings with controlled molecular architecture were evaluated to determine the effect of compositional variables such as filler loading and crosslink density on pseudobarnacle attachment strength. Pseudobarnacle adhesion values correlated with filler loadings in both condensation and hydrosilylation-cured silicones. Variation of crosslink density of hydrosilylation-cured silicones had an insignificant effect on attachment strength. X-ray photoelectron spectroscopy (XPS) indicated that the mode of failure upon detachment of the pseudobarnacle was dependent upon the crosslink density; samples with high crosslink density failed cohesively within the silicone.


Removal Of Pcr Inhibitors From Soil Dna By Chemical Flocculation, Michael D. Braid, Laura M. Daniels, Christopher L. Kitts Mar 2003

Removal Of Pcr Inhibitors From Soil Dna By Chemical Flocculation, Michael D. Braid, Laura M. Daniels, Christopher L. Kitts

Biological Sciences

Extracting high-purity DNA directly from soil has become essential for the study of microorganisms in environmental samples. However, many soils contain compounds that inhibit enzymes involved in manipulating DNA. In this study, chemical flocculation using multivalent cations was investigated as a potential method for eliminating soil-based inhibitors during the extraction process. The addition of AlNH4(SO4)2 during extraction significantly reduced the co-purification of PCR inhibitors with minimal loss of DNA yield.


Nutrition Treatment For Hiv Wasting: A Prescription For Food As Medicine, Ann Y. Mcdermott, Abby Shevitz, Aviva Must, Susan Harris, Ronenn Roubenoff, Sherwood Gorbach Feb 2003

Nutrition Treatment For Hiv Wasting: A Prescription For Food As Medicine, Ann Y. Mcdermott, Abby Shevitz, Aviva Must, Susan Harris, Ronenn Roubenoff, Sherwood Gorbach

Kinesiology

The optimal nutrition approach for the promotion of weight gain in HIV-infected adults with wasting remains unclear. Previous dietary interventions report minimal success and provide inadequate information regarding the counseling approach, contact time, session format, and issues addressed with the subject. The methods we report were incorporated in a 12-week intervention trial for the reversal of HIV-wasting. Methods: All subjects involved in the intervention trial for the reversal of HIV-wasting received weekly, customized, one-on-one counseling and an oral nutrition supplement (480 kcal/d with 30 g protein). The nutrition aims were to (1) increase caloric intake to surpass daily energy ...


Aerobic Endospore Distribution In A Process To Produce High Phospholipid Ingredients From Commercial Reconstituted Buttermilk, L. Lassonde, Rafael Jiménez-Flores Jan 2003

Aerobic Endospore Distribution In A Process To Produce High Phospholipid Ingredients From Commercial Reconstituted Buttermilk, L. Lassonde, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2003 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.


When Does A Reproducing Female Viper (Vipera Aspis) ‘Decide’ On Her Litter Size?, Olivier Lourdais, Xavier Bonnet, Richard Shine, Emily N. Taylor Jan 2003

When Does A Reproducing Female Viper (Vipera Aspis) ‘Decide’ On Her Litter Size?, Olivier Lourdais, Xavier Bonnet, Richard Shine, Emily N. Taylor

Biological Sciences

Some organisms rely on stored energy to fuel reproductive expenditure (capital breeders) whereas others use energy gained during the reproductive bout itself (income breeders). Most species occupy intermediate positions on this continuum, but few experimental data are available on the timescale over which food intake can affect fecundity. Mark–recapture studies of free-ranging female aspic vipers Vipera aspis have suggested that reproductive output relies not only on the energy in fat bodies accumulated in previous years, but also on food intake immediately before ovulation. A simple experiment was conducted to test this hypothesis, maintaining female snakes in captivity throughout the ...


Evolution And Plasticity Of Photosynthetic Thermal Tolerance, Specific Leaf Area And Leaf Size: Congeneric Species From Desert And Coastal Environments, Charles A. Knight, David D. Ackerly Jan 2003

Evolution And Plasticity Of Photosynthetic Thermal Tolerance, Specific Leaf Area And Leaf Size: Congeneric Species From Desert And Coastal Environments, Charles A. Knight, David D. Ackerly

Biological Sciences

• We examined whether increased high temperature photosynthetic thermal tolerance (PT), reduced specific leaf area (SLA) and reduced leaf size represent correlated and convergent adaptations for recently diverged Encelia, Salvia, Atriplex and Eriogonumcongeneric species pairs from contrasting thermal and water environments (the Mojave Desert and coastal California). We also studied whether variation in PT is associated with inducible small heat shock protein expression (sHsp).

• Traits were measured in a common environment (CE) and in the field to partition effects of phenotypic plasticity and genetic divergence.

• We found little evidence for convergent adaptation of PT (CE measurements). Field measurements revealed significant ...


Small Heat Shock Protein Responses Of A Closely Related Pair Of Desert And Coastal Encelia, Charles A. Knight, David D. Ackerly Jan 2003

Small Heat Shock Protein Responses Of A Closely Related Pair Of Desert And Coastal Encelia, Charles A. Knight, David D. Ackerly

Biological Sciences

Evolutionary variation for accumulation of small heat shock protein (sHsp) may contribute to thermal niche differentiation between species. Here we examine temperature and time-course-dependent variation for sHsp accumulation in a recently diverged pair of Encelia raised in a common environment: Encelia farinosa, common in the Mojave desert, and Encelia californica, which is found along the cool coastal bluffs of southern North America. Both species exhibit peak sHsp accumulation at 42oC. Encelia californica accumulated greater levels of sHsp at temperatures below 42oC, while E. farinosa had greater levels above 42oC. Encelia farinosa accumulates sHsp at ...


Monitoring Spores And Spore-Forming Bacteria Populations In Commercial Skim Milk Powder Production Plants Using Conventional And Molecular Methods, C. Murillo, Chris Kitts, Rafael Jiménez-Flores Jan 2003

Monitoring Spores And Spore-Forming Bacteria Populations In Commercial Skim Milk Powder Production Plants Using Conventional And Molecular Methods, C. Murillo, Chris Kitts, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2003 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.


Cheeses From Different Countries Of Latino America, V. Alvarez, Rafael Jiménez-Flores Jan 2003

Cheeses From Different Countries Of Latino America, V. Alvarez, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2003 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.


Development Of Endospore-Specific Primers For The Analysis Of Microbial Populations In Milk Powder, M. M. Arendts, Chris Kitts, Rafael Jiménez-Flores Jan 2003

Development Of Endospore-Specific Primers For The Analysis Of Microbial Populations In Milk Powder, M. M. Arendts, Chris Kitts, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2003 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.


Effect Of Pore Size And Temperature On The Factionation Of Buttermilk Using Microfiltration, Pierre Morin, Rafael Jiménez-Flores, Yves Pouliot Jan 2003

Effect Of Pore Size And Temperature On The Factionation Of Buttermilk Using Microfiltration, Pierre Morin, Rafael Jiménez-Flores, Yves Pouliot

Dairy Science

Abstract of paper presented at the 2003 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.