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Full-Text Articles in Life Sciences

Modeling The Acquisition Of Social Rank In Crayfish: Winner And Loser Effects And Self-Structuring Properties, Karlo Hock, Robert Huber Dec 2005

Modeling The Acquisition Of Social Rank In Crayfish: Winner And Loser Effects And Self-Structuring Properties, Karlo Hock, Robert Huber

Robert Huber

No abstract provided.


Climatic Unpredictability And Parasitism Of Caterpillars: Implications Of Global Warming, John O. Stireman Iii, Lee A. Dyer, D. H. Janzen, M. S. Singer, J. T. Lill, R. J. Marquis, R. E. Ricklefs, G. L. Gentry, W. Hallwachs, P. D. Coley, J. A. Barone, H. F. Greeney, H. Connahs, P. Barbosa, H. C. Morais, I. R. Diniz Nov 2005

Climatic Unpredictability And Parasitism Of Caterpillars: Implications Of Global Warming, John O. Stireman Iii, Lee A. Dyer, D. H. Janzen, M. S. Singer, J. T. Lill, R. J. Marquis, R. E. Ricklefs, G. L. Gentry, W. Hallwachs, P. D. Coley, J. A. Barone, H. F. Greeney, H. Connahs, P. Barbosa, H. C. Morais, I. R. Diniz

Robert Marquis

Insect outbreaks are expected to increase in frequency and intensity with projected changes in global climate through direct effects of climate change on insect populations and through disruption of community interactions. Although there is much concern about mean changes in global climate, the impact of climatic variability itself on species interactions has been little explored. Here, we compare caterpillar–parasitoid interactions across a broad gradient of climatic variability and find that the combined data in 15 geographically dispersed databases show a decrease in levels of parasitism as climatic variability increases. The dominant contribution to this pattern by relatively specialized parasitoid wasps …


The Three Dimensional Detection Of Microvasculatory Bed In The Brain Of White Rat Rattus Norvegicus By A Ca2+ -Atpase Method., Amaiak Chilingaryan, Amayak Chilingaryan, Gary Martin Nov 2005

The Three Dimensional Detection Of Microvasculatory Bed In The Brain Of White Rat Rattus Norvegicus By A Ca2+ -Atpase Method., Amaiak Chilingaryan, Amayak Chilingaryan, Gary Martin

Gary Martin

A procedure is described which allows for the selective and non-injectional staining of the three-dimensional microvasculatory bed (MVB) in thick sections (60–140 μm) of formalin-fixed brain tissue of white rats Rattus norvegicus. This histochemical method detects ATPase activity and takes place between pH 10.5 and 11.2. Calcium ion is used to capture inorganic phosphate, calcium phosphate is converted to lead phosphate, and subsequently converted to black or dark brown lead sulfide. All vessels are revealed due to a precipitate on the endothelium and smooth muscle cells of arterioles. In some vessels, red blood cells also stain. The background is transparent …


Expression Profiling Of Arabidopsis Stigma Tissue Identifies Stigma-Specific Genes, Rob Swanson, T Clark, D Preuss Oct 2005

Expression Profiling Of Arabidopsis Stigma Tissue Identifies Stigma-Specific Genes, Rob Swanson, T Clark, D Preuss

Rob Swanson

Plants discriminate among pollen grains that land on the stigma surface, providing compatible pollen with the nutrients and signals required to proceed in pollination, and in many species, recognizing and inhibiting foreign pollen adhesion, hydration, germination and invasion. Much of the stigma machinery involved in these processes remains unknown. It is likely that the expression of a stigma-specific gene program confers specialized structural and functional properties. Here we used microarray technology and cDNA subtraction to build a profile of candidate stigma genes that facilitate early pollination events. Of over 24,000 Arabidopsis genes probed, we identified 11,403 genes expressed in stigma …


Spiroplasma Penaei Sp. Nov., Associated With Mortalities In Penaeus Vannamei, Pacific White Shrimp, Linda M. Nunan, Donald V. Lightner, Marietta A. Oduori, Gail E. Gasparich Oct 2005

Spiroplasma Penaei Sp. Nov., Associated With Mortalities In Penaeus Vannamei, Pacific White Shrimp, Linda M. Nunan, Donald V. Lightner, Marietta A. Oduori, Gail E. Gasparich

Gail Gasparich

A new bacterial strain, designated SHRIMPT, isolated from the haemolymph of the Pacific white shrimp, Penaeus vannamei, was serologically distinct from other spiroplasmas. Cells of this strain were helical in form and variable in length. Examination by electron microscopy revealed wall-less cells delineated by a single cytoplasmic membrane. The organisms grew well in M1D media supplemented with 2 % NaCl. Strain SHRIMPT grew at temperatures of 20–37 °C, with optimum growth occurring at 28 °C. The strain catabolized glucose and hydrolysed arginine, but did not hydrolyse urea. The G+C content of the DNA was 29±1 mol%. Strain SHRIMPT (=ATCC BAA-1082T=CAIM …


Spiroplasma Leucomae Sp. Nov., Isolated In Poland From White Satin Moth (Leucoma Salicis L.) Larvae, Marietta A. Oduori, Jerzy J. Lipa, Gail E. Gasparich Oct 2005

Spiroplasma Leucomae Sp. Nov., Isolated In Poland From White Satin Moth (Leucoma Salicis L.) Larvae, Marietta A. Oduori, Jerzy J. Lipa, Gail E. Gasparich

Gail Gasparich

Spiroplasma sp. strain SMAT, isolated in Poland from white satin moth larvae, Leucoma salicis L. (Lepidoptera: Lymantriidae), was serologically distinct from other Spiroplasma species, groups or subgroups. Dark-field microscopy of the cells revealed the classical helical shape and subsequent transmission electron microscopy revealed cells surrounded by only a single cell membrane (lacking a cell wall). Growth of strain SMAT occurred in M1D medium at 30 °C. Strain SMAT catabolized both glucose and arginine, but did not hydrolyse urea. The G+C content of the DNA was 24±1 mol% as determined by melting temperature analysis. Serological analysis revealed a very weak cross-reactivity …


Callose (Β-1,3 Glucan) Is Essential For Arabidopsis Pollen Wall Patterning, But Not Tube Growth, Rob Swanson Oct 2005

Callose (Β-1,3 Glucan) Is Essential For Arabidopsis Pollen Wall Patterning, But Not Tube Growth, Rob Swanson

Rob Swanson

Background: Callose (β-1,3 glucan) separates developing pollen grains, preventing their underlying walls (exine) from fusing. The pollen tubes that transport sperm to female gametes also contain callose, both in their walls as well as in the plugs that segment growing tubes. Mutations in CalS5, one of several Arabidopsis β-1,3 glucan synthases, were previously shown to disrupt callose formation around developing microspores, causing aberrations in exine patterning, degeneration of developing microspores, and pollen sterility. Results: Here, we describe three additional cals5 alleles that similarly alter exine patterns, but instead produce fertile pollen. Moreover, one of these alleles (cals5-3) resulted in the …


Problem Solving: A Foundation For Modeling, Janet Hodder, George Middendorf, D. Ebert-May Sep 2005

Problem Solving: A Foundation For Modeling, Janet Hodder, George Middendorf, D. Ebert-May

George Middendorf

No abstract provided.


Regulatory Functions Of Phospholipase D And Phosphatidic Acid In Plant Growth, Development, And Stress Responses, Xuemin Wang Sep 2005

Regulatory Functions Of Phospholipase D And Phosphatidic Acid In Plant Growth, Development, And Stress Responses, Xuemin Wang

Xuemin (Sam) Wang

No abstract provided.


Graduate Colloquium, Borbala Mazzag Aug 2005

Graduate Colloquium, Borbala Mazzag

Borbala Mazzag

No abstract provided.


Androdioecy Inferred In The Clam Shrimp Eulimnadia Agassizii (Spinicaudata : Limnadiidae), Stephen Weeks, Ryan Posagi, Michele Cesari, Franca Scanabissi Jul 2005

Androdioecy Inferred In The Clam Shrimp Eulimnadia Agassizii (Spinicaudata : Limnadiidae), Stephen Weeks, Ryan Posagi, Michele Cesari, Franca Scanabissi

Stephen C. Weeks

Androdioecy (mixtures of males and hermaphrodites) is a rare mating system in both the plant and animal kingdoms. Androdioecy has been described in three branchiopod species, and is best known from the clam shrimp Eulimnadia texana Packard. Herein we describe sex ratio, genetic and histological evidence from the clam shrimp Eulimnadia agassizii Packard that suggest androdioecy is also found in this species. The E. agassizii population sampled had all-females, and when these females were isolated and allowed to produce eggs, those eggs yielded 100% female offspring in 15 out of 15 cases. Additionally, the originally isolated females proved to be …


Barriers And Flow As Limiting Factors In The Spread Of An Invasive Crayfish (Procambarus Clarkii) In Southern California Streams, Jacob Kerby, Seth Riley, Lee Kats, Paul Wilson Jul 2005

Barriers And Flow As Limiting Factors In The Spread Of An Invasive Crayfish (Procambarus Clarkii) In Southern California Streams, Jacob Kerby, Seth Riley, Lee Kats, Paul Wilson

Lee Kats

Invasive crayfish are a major threat to stream ecosystems, yet research has seldom identified successful ways of preventing their spread. Thirty-two stream sections were surveyed during 2000 and 2001 in the Santa Monica Mountains of southern California to determine the distribution of the invasive crayfish Procambarus clarkii. Streams with large barriers (waterfalls, culverts) often did not have crayfish present upstream of barriers. A mark-recapture study indicated that P. clarkii moved both up and downstream between pools, but that barriers significantly reduced movement between pools. Seasonal high flow velocities likely increase passive movement downstream and reduce movement upstream. Results indicate that …


The Reef Fish Assemblage Of The Outer Los Angeles Federal Breakwater, 2002–2003, John Froeschke, Larry Allen, Daniel Pondella Jul 2005

The Reef Fish Assemblage Of The Outer Los Angeles Federal Breakwater, 2002–2003, John Froeschke, Larry Allen, Daniel Pondella

Daniel Pondella

The conspicuous and cryptic fish assemblage of the Los Angeles Federal Breakwater was assessed from 2002 to 2003. Thirty-five species were observed or collected during the study period. The assemblage of cryptic fishes was composed primarily of a mix of Oregonian and San Diegan, species including snubnose sculpin (Orthonopias triacis), coralline sculpin (Artedius corallinus) and blackeye goby (Rhinogobiops nicholsii). The species composition of conspicuous fishes was approximately equal between taxa from these two provinces. Blacksmith (Chromis punctipinnis), black perch (Embiotoca jacksoni) and kelp bass (Paralabrax clathratus) dominated the assemblage of conspicuous fishes. Species composition reflects the localized cool temperature regime …


Digenic Control Of Colouration In The Two-Spot Gourami Trichogaster Trichopterus Trichopterus, Jack Frankel Jul 2005

Digenic Control Of Colouration In The Two-Spot Gourami Trichogaster Trichopterus Trichopterus, Jack Frankel

Jack Frankel

Labyrinth  fishes  of  the  families  Anabantidae,  Belontiidae,Helostomatidae,  and  Osphronemidae  comprise the  tradi-tional  anabantoids,  a  group  of  about  80  relatively  small African  and  southeast  Asian  species (Linke  1991).  Many of  the  anabantoids  are  popular  with  aquarium  hobbyists because of their interesting reproductive behaviours, with males of most species brooding eggs in their mouths or in floating bubble nests (Vevers 1980; Linke 1991; Axelrod and Vorderwinkler 1995; Mills 2000). They have also beenthe focus of several environmental, morphological, and gene-tic  investigations  (Sommer  1982;  Gosline  1985;  Waki-yama  et  al. 1997;  Frankel  1992,  2001).  The  two-spot gourami,   Trichogaster  trichopterus  trichopterus  Pallas (Osphronemidae),  is …


Quasistatic And Continuous Dynamic Characterization Of The Mechanical Properties Of Silk From The Cobweb Of The Black Widow Spider Latrodectus Hesperus, Todd A. Blackledge, John E. Swindeman, Cheryl Y. Hayashi Apr 2005

Quasistatic And Continuous Dynamic Characterization Of The Mechanical Properties Of Silk From The Cobweb Of The Black Widow Spider Latrodectus Hesperus, Todd A. Blackledge, John E. Swindeman, Cheryl Y. Hayashi

Todd A. Blackledge

Spider silks are among the strongest and toughest known materials, but investigation of these remarkable properties has been confined largely to orb-weaving spiders. We investigated the mechanical performance of silk from the cobweb-weaving spider Latrodectus hesperus. Both silk from the scaffolding region of the web and sticky gumfooted capture lines had material properties similar to the major ampullate silk that orb weavers use as the framework for their orb webs. Major ampullate fibers obtained from anaesthetized Latrodectus spiders were similar, but exhibited increased stiffness and reduced extensibility. Novel continuous dynamic analysis of the silks revealed that the loss tangent (tan …


No Relationship Between Sequence Variation In Protein Coding Regions Of The Tas1r3 Gene And Saccharin Preference In Rats., Clinton Chapman, Ke Lu, Amanda Mcdaniel, Michael Tordoff, Li Xia, Gary Beauchamp, Nancy Dess, Dennis Vanderweele, Liquan Huang, Hong Wang, Danielle Reed Feb 2005

No Relationship Between Sequence Variation In Protein Coding Regions Of The Tas1r3 Gene And Saccharin Preference In Rats., Clinton Chapman, Ke Lu, Amanda Mcdaniel, Michael Tordoff, Li Xia, Gary Beauchamp, Nancy Dess, Dennis Vanderweele, Liquan Huang, Hong Wang, Danielle Reed

Clinton D Chapman

Nearly all mammalian species like sweet-tasting foods and drinks, but there are differences in the degree of 'sweet tooth' both between species and among individuals of the same species. Some individual differences can be explained by genetic variability. Polymorphisms in a sweet taste receptor (Tas1r3) account for a large fraction of the differences in consumption of sweet solutions among inbred mouse strains. We wondered whether mice and rats share the same Tas1r3 alleles, and whether this gene might explain the large difference in saccharin preference among rats. We conducted three experiments to test this. We examined DNA sequence differences in …


What Communities Should Do Pre-Event To Support Public Health Post-Event Assessments, Surveillance And Monitoring, Thomas Lyons Carr Iii Feb 2005

What Communities Should Do Pre-Event To Support Public Health Post-Event Assessments, Surveillance And Monitoring, Thomas Lyons Carr Iii

Thomas Lyons (Thom) Carr III Appl.Sc., CEM

[Abstract written March 2008, TLC] Under worst-case planning assumptions used by some major metropolitan areas, a Neighbor-to-Neighbor self-help program model is the primary link between citizens and the professional response personnel of the responsible government agencies.

In the Neighbor-to-Neighbor self-help program model or a Community Emergency Management Plan (CEMP) calls on the citizens in neighborhoods to identify and establish cluster emergency preparedness committees, Cluster Emergency Coordination Centers (CECC) and Community Emergency Response Teams (CERT). Missing from these plans or what is not articulated is how constant Public Health Post-Event Surveillance, Monitoring and Assessments will be done. Given the worst-case planning …


Biogeography Of The Nearshore Rocky-Reef Fishes At The Southern And Baja California Islands, Daniel Pondella, Brooke Gintert, Jana Cobb, Larry Allen Jan 2005

Biogeography Of The Nearshore Rocky-Reef Fishes At The Southern And Baja California Islands, Daniel Pondella, Brooke Gintert, Jana Cobb, Larry Allen

Daniel Pondella

No abstract provided.


Plethodon Albagula (Western Slimy Salamander), Vocalization, Joseph Milanovich Dec 2004

Plethodon Albagula (Western Slimy Salamander), Vocalization, Joseph Milanovich

Joseph Milanovich

No abstract provided.


Presence And Colonization Of Placobdella On Two Species Of Freshwater Turtles (Graptemys Geographica And Sternotherus Odoratus), Travis Ryan Dec 2004

Presence And Colonization Of Placobdella On Two Species Of Freshwater Turtles (Graptemys Geographica And Sternotherus Odoratus), Travis Ryan

Travis J. Ryan

It is generally accepted that bottom-dwelling turtles have a higher ectoparasite load than turtles that bask aerially because of effects of desiccation on ectoparasites, especially with regard to leeches. We compared number of leeches (primarily Placobdella parasitica) on field-caught Common Musk Turtles (Stemotherus odoratus) and Common Map Turtles (Graptemys geographica). The bottom-dwelling species S. odoratus had more than 20 times the number of leeches than the aerial-basking species G. geographica. We then exposed cleaned (leech-free) turtles to leeches in mesocosms (cattle tanks) to measure the rate of colonization. In this experiment, S. odoratus had more than four times the number …


Diadophis Punctatus Sticktogenys (Mississippi Ringneck Snake), Diet, Joseph Milanovich Dec 2004

Diadophis Punctatus Sticktogenys (Mississippi Ringneck Snake), Diet, Joseph Milanovich

Joseph Milanovich

No abstract provided.


Sonora Semiannulata (Ground Snake), Geographic Distribution And Range Extension, Joseph Milanovich Dec 2004

Sonora Semiannulata (Ground Snake), Geographic Distribution And Range Extension, Joseph Milanovich

Joseph Milanovich

No abstract provided.


Ecological Divergence Among Five Co-Occurring Species Of Old-Field Goldenrods, Warren Abrahamson, K. Ball Dobley Dec 2004

Ecological Divergence Among Five Co-Occurring Species Of Old-Field Goldenrods, Warren Abrahamson, K. Ball Dobley

Warren G. Abrahamson, II

No abstract provided.


Water Flow In Roots: Structural And Regulatory Features, Gretchen North, C. Peterson Dec 2004

Water Flow In Roots: Structural And Regulatory Features, Gretchen North, C. Peterson

Gretchen North

No abstract provided.


Effects Of Urbanization On The Distribution And Abundance Of Amphibians And Invasive Species In Southern California Streams, Seth Riley, Gary Busteed, Lee Kats, Thomas Vandergon, Lena Lee, Rosi Dagit, Jacob Kerby, Robert Fisher, Raymond Sauvajot Dec 2004

Effects Of Urbanization On The Distribution And Abundance Of Amphibians And Invasive Species In Southern California Streams, Seth Riley, Gary Busteed, Lee Kats, Thomas Vandergon, Lena Lee, Rosi Dagit, Jacob Kerby, Robert Fisher, Raymond Sauvajot

Lee Kats

Urbanization negatively affects natural ecosystems in many ways, and aquatic systems in particular. Urbanization is also cited as one of the potential contributors to recent dramatic declines in amphibian populations. From 2000 to 2002 we determined the distribution and abundance of native amphibians and ex- otic predators and characterized stream habitat and invertebrate communities in 35 streams in an urbanized landscape north of Los Angeles (U.S.A.). We measured watershed development as the percentage of area within each watershed occupied by urban land uses. Streams in more developed watersheds often had exotic crayfish ( Procambarus clarkii) and fish, and had fewer …


Vh Gene Usage In Humans: Biased Usage Of The Vh6 Gene In Immature B Lymphoid Cells, Jeffrey Berman, Katherine Nickerson, Roberta Pollock, Jeremy Barth, Ruud Schuurman, Daniel Knowles, Leonard Chess, Frederick Alt Dec 2004

Vh Gene Usage In Humans: Biased Usage Of The Vh6 Gene In Immature B Lymphoid Cells, Jeffrey Berman, Katherine Nickerson, Roberta Pollock, Jeremy Barth, Ruud Schuurman, Daniel Knowles, Leonard Chess, Frederick Alt

Roberta Pollock

No abstract provided.


Classical Conditioning Of Red-Backed Salamanders, Plethodon Cinereus, Scott Kight Dec 2004

Classical Conditioning Of Red-Backed Salamanders, Plethodon Cinereus, Scott Kight

Scott Kight


We examined associative learning as it relates to the sensory ecology of the red-backed salamander, Plethodon cinereus, using a classical conditioning design to evaluate the response of salamanders to different kinds of stimuli.  Conditioned stimuli (CS) reflected visual, chemosensory, and mechanosensory modalities of P. cinereus, with brief exposures to (I) white light, (II) acetic acid fumes, (III) low-frequency sound, and (IV) low-frequency vibration.  In all experiments, a gentle mechanical stimulation of the tail served as the unconditioned stimulus (US), which consistently elicited movement of the head or body as the unconditioned response (UR).  For two days, the US …


Yeast Puf3 Mutants Reveal The Complexity Of Puf-Rna Binding And Identify A Loop Required For Regulation Of Mrna Decay, Wendy Olivas, S. S. Houshmandi Dec 2004

Yeast Puf3 Mutants Reveal The Complexity Of Puf-Rna Binding And Identify A Loop Required For Regulation Of Mrna Decay, Wendy Olivas, S. S. Houshmandi

Wendy Olivas

The eukaryotic Puf proteins regulate mRNA translation and degradation by binding the 3' untranslated regions of target mRNAs. Crystal structure analysis of a human Puf bound to RNA suggested a modular mode of binding, with specific amino acids within each of eight repeat domains contacting a single nucleotide of the target RNA. Here we study the mechanism by which the yeast Puf3p binds and stimulates the degradation of COX17 mRNA. Mutation of the predicted RNA-binding positions of Puf3p to those found in Puf5p demonstrated that a single amino acid change in Puf3p abolished detectable binding to COX17. Since this amino …


Profiling Condition-Specific, Genome-Wide Regulation Of Mrna Stability In Yeast, Wendy Olivas, B. C. Foat, S. S. Houshmandi, H. J. Bussemaker Dec 2004

Profiling Condition-Specific, Genome-Wide Regulation Of Mrna Stability In Yeast, Wendy Olivas, B. C. Foat, S. S. Houshmandi, H. J. Bussemaker

Wendy Olivas

The steady-state abundance of an mRNA is determined by the balance between transcription and decay. Although regulation of transcription has been well studied both experimentally and computationally, regulation of transcript stability has received little attention. We developed an algorithm, MatrixREDUCE, that discovers the position-specific affinity matrices for unknown RNA-binding factors and infers their condition-specific activities, using only genomic sequence data and steady-state mRNA expression data as input. We identified and computationally characterized the binding sites for six mRNA stability regulators in Saccharomyces cerevisiae, which include two members of the Pumilio-homology domain (Puf) family of RNA-binding proteins, Puf3p and Puf4p. We …


Plant Ontology (Po): A Controlled Vocabulary Of Plant Structures And Growth Stages, Pankaj Jaiswal, Shulamit Avraham, Katica Ilic, Elizabeth A. Kellogg, Susan Mccouch, Anuradha Pujar, Leonore Reiser, Seung Y. Rhee, Martin M. Sachs, Mary L. Schaeffer, Lincoln Stein, Peter Stevens, Leszek Vincent, Doreen Ware, Felipe Zapata Dec 2004

Plant Ontology (Po): A Controlled Vocabulary Of Plant Structures And Growth Stages, Pankaj Jaiswal, Shulamit Avraham, Katica Ilic, Elizabeth A. Kellogg, Susan Mccouch, Anuradha Pujar, Leonore Reiser, Seung Y. Rhee, Martin M. Sachs, Mary L. Schaeffer, Lincoln Stein, Peter Stevens, Leszek Vincent, Doreen Ware, Felipe Zapata

Peter Stevens

The Plant Ontology Consortium (POC) (www.plantontology.org) is a collaborative effort among several plant databases and experts in plant systematics, botany and genomics. A primary goal of the POC is to develop simple yet robust and extensible controlled vocabularies that accurately reflect the biology of plant structures and developmental stages. These provide a network of vocabularies linked by relationships (ontology) to facilitate queries that cut across datasets within a database or between multiple databases. The current version of the ontology integrates diverse vocabularies used to describe Arabidopsis, maize and rice (Oryza sp.) anatomy, morphology and growth stages. Using the ontology browser, …