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California Polytechnic State University, San Luis Obispo

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Articles 1801 - 1830 of 2152

Full-Text Articles in Life Sciences

An Ecological Basis For Managing Giant Sequoia Ecosystems, Douglas D. Piirto, Robert R. Rogers Jul 2002

An Ecological Basis For Managing Giant Sequoia Ecosystems, Douglas D. Piirto, Robert R. Rogers

Natural Resources Management and Environmental Sciences

A strategy for management of giant sequoia groves is formulated using a conceptual framework for ecosystem management recently developed by Region Five of the USDA Forest Service. The framework includes physical, biological, and social dimensions. Environmental indicators and reference variability for key ecosystem elements are discussed in this paper. The selected ecosystem elements include: 1) attitudes, beliefs, and values; 2) economics and subsistence; 3) stream channel morphology; 4) sediment; 5) water; 6) fire; 7) organic debris; and 8) vegetation mosaic. Recommendations are made for the attributes of environmental indicators that characterize these elements. These elements and associated indicators will define …

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Effects Of Temperature, Epinephrine And Ca2+ On The Hearts Of Yellowfin Tuna (Thunnus Albacares), Jason M. Blank, Jeffery M. Morrissette, Peter S. Davie, Barbara A. Block Jul 2002

Effects Of Temperature, Epinephrine And Ca2+ On The Hearts Of Yellowfin Tuna (Thunnus Albacares), Jason M. Blank, Jeffery M. Morrissette, Peter S. Davie, Barbara A. Block

Biological Sciences

Tuna are endothermic fish with high metabolic rates, cardiac outputs and aerobic capacities. While tuna warm their skeletal muscle, viscera, brain and eyes, their hearts remain near ambient temperature, raising the possibility that cardiac performance may limit their thermal niches. We used an in situ perfused heart preparation to investigate the effects of acute temperature change and the effects of epinephrine and extracellular Ca2+ on cardiac function in yellowfin tuna (Thunnus albacares). Heart rate showed a strong temperature-dependence, ranging from 20 beats min-1 at 10 °C to 109 beats min-1 at 25 °C. Maximal stroke …

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Litr, A New Transcriptional Activator In Vibrio Fischeri, Regulates Luminescence And Symbiotic Light Organ Colonization, Pat Fidopiastis, Carol M. Miyamoto, Michael G. Jobling, Edward A. Meighen, Edward G. Ruby Jul 2002

Litr, A New Transcriptional Activator In Vibrio Fischeri, Regulates Luminescence And Symbiotic Light Organ Colonization, Pat Fidopiastis, Carol M. Miyamoto, Michael G. Jobling, Edward A. Meighen, Edward G. Ruby

Biological Sciences

Vibrio fischeri is the bacterial symbiont within the light-emitting organ of the sepiolid squid Euprymna scolopes . Upon colonizing juvenile squids, bacterial symbionts grow on host-supplied nutrients, while providing a bioluminescence that the host uses during its nocturnal activities. Mutant bacterial strains that are unable to emit light have been shown to be defective in normal colonization. A 606 bp open reading frame was cloned from V. fischeri that encoded a protein, which we named LitR, that had about 60% identity to four related regulator proteins: Vibrio cholerae HapR, Vibrio harveyi LuxR, Vibrio parahaemolyticus OpaR and Vibrio vulnificus SmcR. When …

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Predicting Plant Invasion With Modeling, Scott J. Steinmaus Jul 2002

Predicting Plant Invasion With Modeling, Scott J. Steinmaus

Biological Sciences

No abstract provided.

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Chaperones As Buffering Agents?, Thomas Mitchell-Olds, Charles A. Knight Jun 2002

Chaperones As Buffering Agents?, Thomas Mitchell-Olds, Charles A. Knight

Biological Sciences

No abstract provided.

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Comparative Phenotypic, Molecular, And Virulence Characterization Of Vibrio Parahaemolyticus O3:K6 Isolates, P.S. Marie Yeung, Micaela C. Hayes, Angelo Depaola, Charles A. Kaysner, Laura Kornstein Jun 2002

Comparative Phenotypic, Molecular, And Virulence Characterization Of Vibrio Parahaemolyticus O3:K6 Isolates, P.S. Marie Yeung, Micaela C. Hayes, Angelo Depaola, Charles A. Kaysner, Laura Kornstein

Biological Sciences

Historically, Vibrio parahaemolyticus infections have been characterizedby sporadic cases caused by multiple, diverse serotypes. However,since 1996, V. parahaemolyticus serotype O3:K6 strains havebeen associated with several large-scale outbreaks of illness,suggesting the emergence of a "new" group of organisms withenhanced virulence. We have applied three different molecularsubtyping techniques to identify an appropriate method for differentiatingO3:K6 isolates from other serotypes. Pulsed-field gel electrophoresis(PFGE) following NotI digestion differentiated seven closelyrelated subtypes among O3:K6 and related strains, which weredistinct from PFGE patterns for non-O3:K6 isolates. Ribotypingand tdh sequencing were less discriminatory than PFGE, but furtherconfirmed close genetic relationships among recent O3:K6 isolates.In vitro adherence …

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Review Of Entomology & Pest Management, By Larry P. Pedigo, 4th Edition, Mark D. Shelton Jun 2002

Review Of Entomology & Pest Management, By Larry P. Pedigo, 4th Edition, Mark D. Shelton

Office of the Dean (CAFES) Scholarship

Review of Entomology & Pest Management by Larry P. Pedigo, 4th edition, Prentice Hall, 2002, 742 pp., Hardbound. $78.75.

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The Production Of Communication Signals At The Air–Water And Water–Substrate Boundaries, Sean C. Lema, John T. Kelly Jun 2002

The Production Of Communication Signals At The Air–Water And Water–Substrate Boundaries, Sean C. Lema, John T. Kelly

Biological Sciences

The 2 interfaces of the aquatic environment, the boundary between air–water and water–substrate, have distinctive physical characteristics that facilitate the production of communication signals. Recent evidence suggests that animals living on or near these boundaries use the interface to generate signals in 2 ways: (a) by producing a signal that propagates along the interface or (b) by producing a signal at the interface that is transmitted and detected within 1 of the component media. By examining the diversity of behaviors used to produce signals at these boundaries, the authors illustrate how human perception of these environments may cause researchers to …

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Dietary Patterns And Prostate Cancer Risk In The Nhefs Cohort, Marilyn Tseng Jun 2002

Dietary Patterns And Prostate Cancer Risk In The Nhefs Cohort, Marilyn Tseng

Kinesiology and Public Health

We examined the association between dietary patterns and prostate cancer risk using data from the first National Health and Nutrition Examination Epidemiologic Follow-up Study. The study population included 3,779 men followed 1982-4 to 1992, with 136 prostate cancer cases identified during the follow-up. Principal components analysis on responses to a lOS-item diet questionnaire in 1982-84 was used to identify dietary patterns, and scores representing level of intake of each pattern were categorized into tertiles. Three distinct patterns were identified: a vegetable-fruit pattern, a red meat-starch pattern characterized by intake of beef, pork, potatoes, and sweets, and a southern pattern characterized …

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Combining Behavioral And Pharmacological Treatments For Obesity, Suzanne Phelan, Thomas A. Wadden Jun 2002

Combining Behavioral And Pharmacological Treatments For Obesity, Suzanne Phelan, Thomas A. Wadden

Kinesiology and Public Health

Weight-loss medications are currently recommended for use only as an adjunct to diet, exercise, and behavior modification. Little, however, is known about the benefits of combining behavioral and pharmacological therapies or about the mechanisms that would make these combined approaches more effective than either used alone. This article reviews the effects of adding pharmacotherapy (i.e., principally sibutramine and orlistat) to a modest program of lifestyle modification. Studies revealed that the addition of medication typically improved short- and long-term weight loss compared with lifestyle modification alone. The best results, however, were obtained when medications were combined with an intensive, group program …

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Species-Specific Identification Of Commercial Probiotic Strains, Marie Yeung, M. E. Sanders, Christopher L. Kitts, Raul Cano, Phillip S. Tong May 2002

Species-Specific Identification Of Commercial Probiotic Strains, Marie Yeung, M. E. Sanders, Christopher L. Kitts, Raul Cano, Phillip S. Tong

Biological Sciences

Products containing probiotic bacteria are gaining popularity, increasing the importance of their accurate speciation. Unfortunately, studies have suggested that improper labeling of probiotic species is common in commercial products. Species identification of a bank of commercial probiotic strains was attempted using partial 16S rDNA sequencing, carbohydrate fermentation analysis, and cellular fatty acid methyl ester analysis. Results from partial 16S rDNA sequencing indicated discrepancies between species designations for 26 out of 58 strains tested, including two ATCC Lactobacillus strains. When considering only the commercial strains obtained directly from the manufacturers, 14 of 29 strains carried species designations different from those obtained …

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The Long-Term Ecosystem Observatory: An Integrated Coastal Observatory, Oscar Schofield, Trisha Bergmann, Paul Bissett, J. Frederick Grassle, Dale B. Haidvogel, Josh Kohut, Mark A. Moline, Scott M. Glenn Apr 2002

The Long-Term Ecosystem Observatory: An Integrated Coastal Observatory, Oscar Schofield, Trisha Bergmann, Paul Bissett, J. Frederick Grassle, Dale B. Haidvogel, Josh Kohut, Mark A. Moline, Scott M. Glenn

Biological Sciences

An integrated ocean observatory has been developed and operated in the coastal waters off the central coast of New Jersey, USA. One major goal for the Long-term Ecosystem Observatory (LEO) is to develop a real-time capability for rapid environmental assessment and physical/biological forecasting in coastal waters. To this end, observational data are collected from satellites, aircrafts, ships, fixed/relocatable moorings and autonomous underwater vehicles. The majority of the data are available in real-time allowing for adaptive sampling of episodic events and are assimilated into ocean forecast models. In this observationally rich environment, model forecast errors are dominated by uncertainties in the …

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A New Auv Platform For Studying Near Shore Bioluminescence Structure, Mark A. Moline, S. Blackwell, J. Case, S. Glenn, J. Kohut, O. Schofield, M. Purcell, C. Vonalt Apr 2002

A New Auv Platform For Studying Near Shore Bioluminescence Structure, Mark A. Moline, S. Blackwell, J. Case, S. Glenn, J. Kohut, O. Schofield, M. Purcell, C. Vonalt

Biological Sciences

Peaks in bioluminescence are often associated with small spatial features including frontal boundaries, vertical thin-layers, and convergence/divergence zones.1,2 Due to the highly variable nature of these features in the near shore environment, accurate assessment of bioluminescence potential is dependent upon the application of appropriate platforms and the use of these platforms at relevant time and space scales. Both traditional shipboard profiling techniques and moored vertical profiling instrumentation fail to adequately provide the appropriate spatial resolution to explain the dynamics of near shore bioluminescence. In an effort to resolve the mechanisms underlying the temporal and spatial variation in near shore …

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Interspecific- And Acclimation-Induced Variation In Levels Of Heat-Shock Proteins 70 (Hsp70) And 90 (Hsp90) And Heat-Shock Transcription Factor-1 (Hsf1) In Congeneric Marine Snails (Genus Tegula): Implications For Regulation Of Hsp Gene Expression, Lars Tomanek, George N. Somero Mar 2002

Interspecific- And Acclimation-Induced Variation In Levels Of Heat-Shock Proteins 70 (Hsp70) And 90 (Hsp90) And Heat-Shock Transcription Factor-1 (Hsf1) In Congeneric Marine Snails (Genus Tegula): Implications For Regulation Of Hsp Gene Expression, Lars Tomanek, George N. Somero

Biological Sciences

In our previous studies of heat-shock protein (hsp) expression in congeneric marine gastropods of the genus Tegula, we observed interspecific and acclimation-induced variation in the temperatures at which heat-shock gene expression is induced (Ton). To investigate the factors responsible for these inter- and intraspecific differences in Ton, we tested the predictions of the ‘cellular thermometer’ model for the transcriptional regulation of hsp expression. According to this model, hsps not active in chaperoning unfolded proteins bind to a transcription factor, heat-shock factor-1 (HSF1), thereby reducing the levels of free HSF1 that are available to bind …

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Occam's Razor & The Nature Of Scientific Theories, William D. Stansfield Feb 2002

Occam's Razor & The Nature Of Scientific Theories, William D. Stansfield

Biological Sciences

No abstract provided.

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An Ecological And Evolutionary Analysis Of Photosynthetic Thermotolerance Using The Temperature-Dependent Increase In Fluorescence, Charles A. Knight, David D. Ackerly Feb 2002

An Ecological And Evolutionary Analysis Of Photosynthetic Thermotolerance Using The Temperature-Dependent Increase In Fluorescence, Charles A. Knight, David D. Ackerly

Biological Sciences

The hypothesis that species inhabiting warmer regions have greater photosynthetic tolerance of high temperatures was tested using the temperature-dependent increase in fluorescence (T-Fo). Congeneric species pairs of Atriplex, Salvia, Encelia, and Eriogonum with desert versus coastal distributions were studied in a common environment and in the field. In addition, 21 species with contrasting microclimate distributions were studied at a field site in a northern California chaparral community. The average July maximum temperature within the current distributions of species was quantified using a geographic information system. Four parameters (Tcrit, TS20, …

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Leaf Size, Specific Leaf Area And Microhabitat Distribution Of Chaparral Woody Plants: Contrasting Patterns In Species Level And Community Level Analyses, D. D. Ackerly, Charles A. Knight, S. B. Weiss, K. Barton, K. P. Starmer Feb 2002

Leaf Size, Specific Leaf Area And Microhabitat Distribution Of Chaparral Woody Plants: Contrasting Patterns In Species Level And Community Level Analyses, D. D. Ackerly, Charles A. Knight, S. B. Weiss, K. Barton, K. P. Starmer

Biological Sciences

We examined variation in leaf size and specific leaf area (SLA) in relation to the distribution of 22 chaparral shrub species on small-scale gradients of aspect and elevation. Potential incident solar radiation (insolation) was estimated from a geographic information system to quantify microclimate affinities of these species across north- and south-facing slopes. At the community level, leaf size and SLA both declined with increasing insolation, based on average trait values for the species found in plots along the gradient. However, leaf size and SLA were not significantly correlated across species, suggesting that these two traits are decoupled and associated with …

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Factors Influencing Cell Count Of A Probiotic Lactobacillus Crispatus Strain, Kevin Bourzac, Ann Bernard, M. E. Sanders, Rafael Jiménez-Flores Jan 2002

Factors Influencing Cell Count Of A Probiotic Lactobacillus Crispatus Strain, Kevin Bourzac, Ann Bernard, M. E. Sanders, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.

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Effects Of Seasonal And Regional Variations In Milk Components On The Buffering Capacity Of Milk In California, A. Harris, Phillip Tong, Sean Vink, Jesus Izco, Rafael Jiménez-Flores Jan 2002

Effects Of Seasonal And Regional Variations In Milk Components On The Buffering Capacity Of Milk In California, A. Harris, Phillip Tong, Sean Vink, Jesus Izco, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.

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Disulfide Bonding Patterns Between Β-Lactoglobulin And Κ-Casein In A Heated And Spray-Dried Milk-Model, Annie Bienvenue, C. S. Norris, Michael J. Boland, Lawrence K. Creamer, Rafael Jiménez-Flores Jan 2002

Disulfide Bonding Patterns Between Β-Lactoglobulin And Κ-Casein In A Heated And Spray-Dried Milk-Model, Annie Bienvenue, C. S. Norris, Michael J. Boland, Lawrence K. Creamer, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.

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Heat-Induced Reactions Involving Β-Lactoglobulin And Other Milk Proteins In Milk, Whey, And Model Systems, Lawrence K. Creamer, G. A. Manderson, Y. H. Hong, P. Havea, Y. H. Cho, H. Singh, Annie Bienvenue, Rafael Jiménez-Flores Jan 2002

Heat-Induced Reactions Involving Β-Lactoglobulin And Other Milk Proteins In Milk, Whey, And Model Systems, Lawrence K. Creamer, G. A. Manderson, Y. H. Hong, P. Havea, Y. H. Cho, H. Singh, Annie Bienvenue, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.

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Utilization Of Dot Blots To Screen Probiotic Lactobacilli For Mucin Binding, J. Newman, Rafael Jiménez-Flores Jan 2002

Utilization Of Dot Blots To Screen Probiotic Lactobacilli For Mucin Binding, J. Newman, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.

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Variation In Nuclear Dna Content Across Environmental Gradients: A Quantile Regression Analysis, Charles A. Knight, David D. Ackerly Jan 2002

Variation In Nuclear Dna Content Across Environmental Gradients: A Quantile Regression Analysis, Charles A. Knight, David D. Ackerly

Biological Sciences

The nuclear DNA content of angiosperms varies by several orders of magnitude. Previous studies suggest that variation in 2C DNA content (i.e. the amount of DNA in G1 phase nuclei, also referred to as the 2C-value) is correlated with environmental factors, but there are conflicting reports in the literature concerning the nature of these relationships. We examined variation in 2C DNA content for 401 species in the ecologically diverse California flora in relation to the mean July maximum temperature, January minimum temperature, and annual precipitation within the geographical ranges of these species. Species with small 2C-values predominate in all environments. …

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Calorimetric Study Of Block-Copolymers Of Poly(N-Butyl Acrylate) And Gradient Poly(N-Butyl Acrylate-Co-Methyl Methacrylate), A I. Buzin, M Pyda, P Costanzo, K Matyjaszewski, B Wunderlich Jan 2002

Calorimetric Study Of Block-Copolymers Of Poly(N-Butyl Acrylate) And Gradient Poly(N-Butyl Acrylate-Co-Methyl Methacrylate), A I. Buzin, M Pyda, P Costanzo, K Matyjaszewski, B Wunderlich

Chemistry and Biochemistry

The nanophase separation in diblock and triblock copolymers consisting of immiscible poly(n-butyl acrylate) (block A) and gradient copolymers of methyl methacrylate (MMA) and n-butyl acrylate (n BA) (block M/A) were investigated by means of their heat capacity, Cp, as a function of the composition of the blocks M/A and temperature. In all copolymers studied, both blocks are represented by their Cp and glass transition temperature, Tg, as well as the broadening of the transition-temperature range. The low-temperature transition of the blocks A is always close to that of the …

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The Detection Of Bacillus Endospores During Low Heat Skim Milk Powder Processing Using Nucleic Acid Technology, Amy J. Rife, Rafael Jiménez-Flores, Chris Kitts, Mark Kubinski Jan 2002

The Detection Of Bacillus Endospores During Low Heat Skim Milk Powder Processing Using Nucleic Acid Technology, Amy J. Rife, Rafael Jiménez-Flores, Chris Kitts, Mark Kubinski

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.

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Extraction Of Lipids From Buttermilk Using Supercritical Carbon Dioxide, Harit K. Vyas, Johanna C. Astaire, Rafael Jiménez-Flores Jan 2002

Extraction Of Lipids From Buttermilk Using Supercritical Carbon Dioxide, Harit K. Vyas, Johanna C. Astaire, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.

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Monitoring Endospores And Endospore-Forming Bacteria Populations In Commercial Skim Milk Powder Production Plants, C. Murillo, Rafael Jiménez-Flores Jan 2002

Monitoring Endospores And Endospore-Forming Bacteria Populations In Commercial Skim Milk Powder Production Plants, C. Murillo, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.

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Sensory And Instrumental Measurements Of The Sensory Properties Of Powdered Buttermilk, M. Spill, Jean-Xavier Guinard, Rafael Jiménez-Flores Jan 2002

Sensory And Instrumental Measurements Of The Sensory Properties Of Powdered Buttermilk, M. Spill, Jean-Xavier Guinard, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.

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Validation Of Capillary Electrophoresis For The Ultra-Rapid Determination Of Inorganic Phosphate And Citrate In Milk, Jesus M. Izco, Monica Tormo, Phillip Tong, Rafael Jiménez-Flores Jan 2002

Validation Of Capillary Electrophoresis For The Ultra-Rapid Determination Of Inorganic Phosphate And Citrate In Milk, Jesus M. Izco, Monica Tormo, Phillip Tong, Rafael Jiménez-Flores

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.

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Two New Species Of Pectis (Asteraceae: Tageteae) From South America, David J. Keil Jan 2002

Two New Species Of Pectis (Asteraceae: Tageteae) From South America, David J. Keil

Biological Sciences

Pectis hassleri and P. pumila are new species, the former from the Gran Chaco area of Paraguay and the latter from southwester Encuador and northwestern Peru. Pectis hassleri differs from P. odorata by leaves that are glandular-punctaoten the adaxial as well as the abaxial surfaces, by longer and wider ligules of the ray florets, and by ray pappi of awns and shorter bristles. Pectis pumila differs from the closely related P. arida by its wider leaves and by its sessile or subsessile capitula with campanulatein volucresa nd obovatep hyllaries.A hexaploid chromosome count of 2n = 361 is newly reported for …

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