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

Life Sciences Commons™

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

1999

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 511 - 540 of 2285

Full-Text Articles in Life Sciences

Mechanisms Of Thermal Stability During Flight In The Honeybee Apis Mellifera, Stephen P. Roberts, Jon F. Harrison Jun 1999

Mechanisms Of Thermal Stability During Flight In The Honeybee Apis Mellifera, Stephen P. Roberts, Jon F. Harrison

Biological Sciences Faculty Research & Creative Works

Thermoregulation of the Thorax Allows Honeybees (Apis Mellifera) to Maintain the Flight Muscle Temperatures Necessary to Meet the Power Requirements for Flight and to Remain Active Outside the Hive Across a Wide Range of Air Temperatures (T(A)). to Determine the Heat-Exchange Pathways through Which Flying Honeybees Achieve Thermal Stability, We Measured Body Temperatures and Rates of Carbon Dioxide Production and Water Vapor Loss between T(A) Values of 21 and 45°C for Honeybees Flying in a Respirometry Chamber. Body Temperatures Were Not Significantly Affected by Continuous Flight Duration in the Respirometer, indicating that Flying Bees Were at Thermal Equilibrium. Thorax Temperatures …


Nou Fall Field Days Count, 1998; May Namc Count, 1999 Jun 1999

Nou Fall Field Days Count, 1998; May Namc Count, 1999

Nebraska Bird Review

The NOU count during Fall Field Days, October 16 through 18, focused on areas in and around the Nebraska National Forest and includes reports from 5 counties: Forest, Blaine, Brown, Cherry, and Thomas. This year's species count, owing in part to inclement weather, registered only 92, far behind the previous year's NOU Fall Field Days record of 122 species.

The North American Migration Count (NAMC) for Pierce County is also included in this report. A total of twelve people in five parties took part in this year's count. The count registered one hour walked and 380 miles covered in 43.5 …


Pararhinebothroides Hobergi N. Gen. N. Sp. (Eucestoda: Tetraphyllidea) In Urobatis Tumbesensis (Chondrichthyes: Myliobatiformes) From Coastal Ecuador, David Zamparo, Daniel R. Brooks, Ramiro Barriga Jun 1999

Pararhinebothroides Hobergi N. Gen. N. Sp. (Eucestoda: Tetraphyllidea) In Urobatis Tumbesensis (Chondrichthyes: Myliobatiformes) From Coastal Ecuador, David Zamparo, Daniel R. Brooks, Ramiro Barriga

Harold W. Manter Laboratory of Parasitology: Faculty Publications

A new species of tetraphyllidean eucestode inhabiting Urobatis tumbesensis from inshore waters of southeastern Ecuador shares 3 synapomorphies with Rhinebothroides spp.: apical bothridial suckers poorly differentiated from the marginal loculi, internal seminal vesicles, and insertion of the vas deferens dorsally closer to the poral than the aporal end of the cirrus sac. The new species differs from Rhinebothroides spp. by lacking medial bothridial septa and loculi and having symmetrical ovarian arms, and possesses an apparent autapomorphic trait by having the vas deferens tapering to a narrow tube before entering the cirrus sac, extending posteriorly to the posterior end of the …


Macroevolutionary Patterns Of Male Reproductive Investment In A Clade Of Parasitic Hermaphrodites, David Zamparo, Deborah A. Mclennan, Daniel R. Brooks Jun 1999

Macroevolutionary Patterns Of Male Reproductive Investment In A Clade Of Parasitic Hermaphrodites, David Zamparo, Deborah A. Mclennan, Daniel R. Brooks

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The Eucestoda is particularly relevant for questions concerning reproductive investment in male gametes because no other parasitic group displays such diversity in testis size and number within and among species. This diversity has long been used as a valuable taxonomic character, but few researchers have ever investigated its evolutionary significance. In this paper we investigate the evolution of testis number and size within Rhinebothroides (Platyhelminthes: Eucestoda). Our comparative, phylogenetic analysis revealed that overall allocation to male functions, as measured by relative testicular area, does not change within the clade, even though the packaging of that investment in numerous testes is …


Species: Turning A Conundrum Into A Research Program, Daniel R. Brooks, Deborah A. Mclennan, E. C. Bernard Jun 1999

Species: Turning A Conundrum Into A Research Program, Daniel R. Brooks, Deborah A. Mclennan, E. C. Bernard

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The most appropriate ontological basis for understanding the role of species in evolutionary biology is the Evolutionary Species Concept. The ESC is not an operational concept, but one version of the Phylogenetic Species Concept is. Linking the ontology of species with the epistemological basis of actual biological studies requires that we specify both a discovery mode for identifying collections of organisms that we believe are evolutionary species, and a series of evaluation criteria for assessing those entities we have discovered. Simply naming a collection of specimens, no matter how strong one’s evolutionary beliefs, is not sufficient for declaring that evolutionary …


An Economic Analysis Of The Threat Of An Exotic Disease On Agriculture: The Case Of Sheep Pox In Western Australia, Nhu Che, Tom Kompas Jun 1999

An Economic Analysis Of The Threat Of An Exotic Disease On Agriculture: The Case Of Sheep Pox In Western Australia, Nhu Che, Tom Kompas

Biosecurity published reports

Sheep pox is an acute disease that causes heavy losses due to high sheep mortality, costly eradication programs and ongoing problems with trade restrictions for many countries around the world. Australia until now has been unaffected, and although the risk of disease entry may be very slight, one case of sheep pox outbreak could cost the Western Australian economy as much as $50 million in damages, mostly from the trade disruption losses ( over the 21-month period of trading bans). The introduction of a Serology Test Program may reduce that amount by $35 million due to a shortening of the …


Characterization Of Nih-3t3 Mouse Fibroblast Cells Transfected With The Somatostatin Receptor Subtype 2 And The Protein Tyrosine Phosphatase Shp-1, Scott Bradford Cross Jun 1999

Characterization Of Nih-3t3 Mouse Fibroblast Cells Transfected With The Somatostatin Receptor Subtype 2 And The Protein Tyrosine Phosphatase Shp-1, Scott Bradford Cross

Masters Theses

The hormone Somatostatin (SMS) and its analogs have been shown to mediate a variety of cellular actions including inhibition of cellular growth and differentiation of endocrine tumors such as insulinomas and glucagonomas. The mechanisms by which SMS exerts its antitumorigenic effects are poorly understood but are thought to include one of the five Somatostatin receptors (SSTR1-5), and the protein tyrosine phosphatase SHP-1. To determine if the antiproliferative effects of SMS were due to the presence of the SSTR2 receptor or the stimulation of SHP-1, we introduced cDNA's of the SMS receptor SSTR2, SHP-1, and a dominant negative mutant of SHP-1 …


Cereal Rust Diseases And Their Management, 1999, Rob Dickie, Rob Loughman, Jat Bhathal Jun 1999

Cereal Rust Diseases And Their Management, 1999, Rob Dickie, Rob Loughman, Jat Bhathal

Technical Bulletins

• Wheat leaf rust (Puccinia recondita f.sp. tritici) is specific to wheat and triticale. A single pathotype (designated 104-1,2,3,(6),(7),11) has dominated in W.A. since 1990. Wheat leaf rust regularly survives the non-cropping summer in varying quantities, usually sufficient to occur at least to a limited extent (particularly in southern regions) each year. The disease develops rapidly between 15 and 22°C when moisture (including dew) is non-limiting. The highest yield increase attributed directly to control of leaf rust in W.A. is 37 per cent. However the disease is synergistically damaging in combination with septoria leaf blotches. In Esperance in …


Acute Effects Of Whole-Body Proton Irradiation On The Immune System Of The C57bl/6 Mouse, Eric H. Kajioka Jun 1999

Acute Effects Of Whole-Body Proton Irradiation On The Immune System Of The C57bl/6 Mouse, Eric H. Kajioka

Loma Linda University Electronic Theses, Dissertations & Projects

The acute effects of proton whole-body irradiation (WBI) on leukocytes, lymphocytes, and hematological parameters in the spleen and blood of C57BI/6 mice were examined and compared to the effects of photon (gamma) WBI derived from a 60cobalt (60Co) source. Adult, female C57BL/6 mice were exposed to a single dose (3 Gy, 0.4 Gy/min dose rate) of either proton WBI at the Bragg peak, proton WBI at the entry plateau, or Co WBI, and sacrifice intervals were at 1,4, 7, and 10 days post- WBI. Flow cytometry analysis of the spleen and peripheral blood showed depression in cell counts for all …


Maternal Modulation Of Neonatal Immunity, Omar R. Fagoaga Jun 1999

Maternal Modulation Of Neonatal Immunity, Omar R. Fagoaga

Loma Linda University Electronic Theses, Dissertations & Projects

Although the neonatal immune system is functionally immature, immune response capabilities are not the same in all newborns. The objective of this thesis was to determine development of immunocompetence and test the hypothesis that activation of maternal inflammatory immunity during pregnancy influences maturation of the neonatal immune system.

Lymphocytes in blood and spleen were immunophenotyped by flow cytometric analysis to determine differentiation characteristics, and splenocytes were assessed for cytokine production capabilities. In normal Th2-prone outbred (CD-1) mice, an adult repertoire of naïve lymphocytes has developed by day 10 and memory cells by day 20, in blood and spleen. However, in …


The Immunology Of Parturition, Ari Mayer Mackler Jun 1999

The Immunology Of Parturition, Ari Mayer Mackler

Loma Linda University Electronic Theses, Dissertations & Projects

Macrophage-derived factors have been implicated in the etiology of preterm labor but little is known about trafficking of this immune cell into the uterus or its regulation of uterine contractility in mice. Enhanced number and activation of macrophages was hypothesized to precede parturition. Studies characterized contractile activity and the distribution of macrophages in the uterus of C3/HeN mice before and after term (=day 19). Contractile activity by uterine strips on days 15 and 18 of pregnancy, the day of delivery, and 1 day postpartum indicate that an endogenous oscillator sustains high frequency contractions. Modest acceleration of the pacemaker occurred before …


The Molecular Systematics Of The Side-Blotched Lizards (Iguania: Phrynosomatidae: Uta), Bradford Damion Hollingsworth Jun 1999

The Molecular Systematics Of The Side-Blotched Lizards (Iguania: Phrynosomatidae: Uta), Bradford Damion Hollingsworth

Loma Linda University Electronic Theses, Dissertations & Projects

The lizard genus Uta comprises nine currently recognized species with the center of diversity occurring on islands in the Gulf of California and Pacific Ocean. The molecular evolution of the side-blotched lizards is analyzed using 1132 base pairs of mitochondrial DNA sequence from the cytochrome b and cytochrome oxidase III genes. Samples come from 98 'individuals from 50 islands in the Gulf of California and Pacific Ocean and 48 adjacent populations from Baja California Sur, Baja California, California, New Mexico, and Sonora. All currently recognized species are represented. Both maximum parsimony and maximum likelihood were used to reconstruct phylogenetic relationships. …


Use Of Bioinformatics In The Analysis Of Chemotaxis Proteins, Sean Andrew Bulloch Jun 1999

Use Of Bioinformatics In The Analysis Of Chemotaxis Proteins, Sean Andrew Bulloch

Loma Linda University Electronic Theses, Dissertations & Projects

Bacterial chemotaxis is one of the best-known signal transduction systems. Levels of attractants and repellents are sensed in the surrounding environment by various chemoreceptors. The signal is passed to the excitation pathway via the transfer of a phosphoryl group from the receptor-associated histidine kinase CheA to the response regulator CheY. Phospho-CheY binds to the flagellar motor switching the direction of rotation of the flagella and thus allowing the cell to move towards or away from the attractant or repellent. The phosphatase CheZ removes the phosphoryl group from phospho-CheY restoring default flagellar rotation. Adaptation to stimuli occurs via addition of methyl …


Engineering Secreted Proteins For Gene Transfer And Dna Vaccination, Jingxue Liu Jun 1999

Engineering Secreted Proteins For Gene Transfer And Dna Vaccination, Jingxue Liu

Loma Linda University Electronic Theses, Dissertations & Projects

In recent years gene therapy has become a promising way of alleviating incurable human ailments, its concept emerging as the ultimate therapy for many infectious and genetic diseases. Two important aspects of the development of successful gene therapy protocols are the ability to monitor gene transfer readily, and the establishment of new protocols for treating specific diseases. In this work, Renilla luciferase and human glutamic acid decarboxylase (GAD) 65 were engineered for secretion to address some aspects of these issues.

Secreted reporter proteins are promising tools to study gene transfer and expression in a non-destructive manner, and bioluminescent proteins are …


Dna-Dna Checkerboard Hybridization To Identify Bacteria In Human Plaque Samples, Jasan Lee Zimmerman Jun 1999

Dna-Dna Checkerboard Hybridization To Identify Bacteria In Human Plaque Samples, Jasan Lee Zimmerman

Loma Linda University Electronic Theses, Dissertations & Projects

Previous research has shown that using DNA probes to identify the presence of specific bacteria in human plaque samples is superior to the commonly used anaerobic cultural procedures. Some periodontal pathogens are either uncultivable or very difficult to grow, such as Prevotella intermedia, P. nigrescens, and Eubacterium brachy. Digoxygenin probes were prepared for 15 oral bacteria. These probes were used with a checkerboard DNA-DNA hybridization scheme to analyze whether human plaque samples contained any of the 15 bacterial species. Our results have shown that this method is successful in identifying bacterial DNA present in the subgingival patient plaque …


Functional Analysis Of Human Igfbp-6 In Human Osteoblasts, Tao Yan Jun 1999

Functional Analysis Of Human Igfbp-6 In Human Osteoblasts, Tao Yan

Loma Linda University Electronic Theses, Dissertations & Projects

Insulin-like growth factor binding proteins (IGFBPs) are a family of six secreted proteins that bind to and modulate the functions of insulin-like growth factors (IGF-I and IGF-II). As a relatively new member of the IGF system, IGFBP-6 was found to be produced by human osteoblasts and exert significant biological effects on human osteoblasts.

Our previous studies indicated that all-trans retinoic acid (ATRA) caused more than a10 fold increase in IGFBP-6 production and a50-60% reduction of ALP activity in human osteoblasts. Based on these findings, we proposed the hypothesis that ATRA induced human osteoblast differentiation was mediated at least in part …


Cropwatch No. 99-11, May 28, 1999, Lisa Brown Jasa May 1999

Cropwatch No. 99-11, May 28, 1999, Lisa Brown Jasa

Crop Watch (1994–2005)

Inside

Field updates ………………..96

Two new specialists ………………..98

Post rain weed control ………………..99

Crop update………………..99

Post corn herbicides………………..100

Bean leaf beetle control………………..101

Purple loosestrife invader………………..102

Precipitation maps………………..103

Common stalk borer………………..103

Destructive pine wilt………………..104

Herbicide damage ………………..104


Novel Application Of Phastsystem Polyacrylamide Gel Electrophoresis Using Restriction Fragment Length Polymorphism ± Internal Transcribed Spacer Patterns Of Individuals For Molecular Identification Of Entomopathogenic Nematodes, Horolma Pamjav, Dimitra Triga, Zsuzsanna Buzµs, Tibor Vellai, Attila Lucskai, Byron Adams, Alexander P. Reid, Ann Burnell, Christine Griffin, Itamar Glazer, Michael G. Klein, Andras Fodor May 1999

Novel Application Of Phastsystem Polyacrylamide Gel Electrophoresis Using Restriction Fragment Length Polymorphism ± Internal Transcribed Spacer Patterns Of Individuals For Molecular Identification Of Entomopathogenic Nematodes, Horolma Pamjav, Dimitra Triga, Zsuzsanna Buzµs, Tibor Vellai, Attila Lucskai, Byron Adams, Alexander P. Reid, Ann Burnell, Christine Griffin, Itamar Glazer, Michael G. Klein, Andras Fodor

Department of Plant Pathology: Faculty Publications

A relatively rapid and economic way of identifying and assigning nematodes to taxons, which had already been determined either by comparative sequence analysis of nuclear rDNA internal transcribed spacer (ITS) region or by other methods of molecular or conventional taxonomy, is provided. Molecular identification of entomopathogenic nematodes (EPN) can be upgraded by basing it on PhastSystem polyacrylamide gel electrophoresis (PAGE) analysis of restriction fragment length polymorphism (RFLP) patterns of polymerase chain reaction (PCR)-amplified DNA derived from single nematodes of Steinernema or Heterorhabditis spp. Although analysis from single worms has previously been made on agarose gel, the resolution on PhastSystem PAGE …


Field And Laboratory Evaluation Of Soil Quality Changes Resulting From Injection Of Liquid Sewage Sludge, S. Stamatiadis, John W. Doran, Timothy A. Kettler May 1999

Field And Laboratory Evaluation Of Soil Quality Changes Resulting From Injection Of Liquid Sewage Sludge, S. Stamatiadis, John W. Doran, Timothy A. Kettler

Department of Agronomy and Horticulture: Faculty Publications

Soil quality changes resulting from repeated or single injection of liquid municipal sewage sludge were evaluated in terraced cropland in eastern Nebraska, USA. Differences in soil properties among sampling locations were explained primarily by two factors, landscape position and sludge injection. Selected chemical properties (pH, EC, NO 3-N) did not generally differ between landscape positions, but soil organic matter (organic C and N) and microbial activity indices (soil respiration, biomass N, available N, mineralization and nitrification rates) were more sensitive indicators of change. Values of these indicators generally increased down-slope from the upper terrace to the grassed waterway on …


Ecological Intensification Of Cereal Production Systems: Yield Potential, Soil Quality, And Precision Agriculture, Kenneth G. Cassman May 1999

Ecological Intensification Of Cereal Production Systems: Yield Potential, Soil Quality, And Precision Agriculture, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Wheat (Triticum aestivum L.), rice (Oryza sativa L.), and maize (Zea mays L.) provide about two-thirds of all energy in human diets, and four major cropping systems in which these cereals are grown represent the foundation of human food supply. Yield per unit time and land has increased markedly during the past 30 years in these systems, a result of intensified crop management involving improved germplasm, greater inputs of fertilizer, production of two or more crops per year on the same piece of land, and irrigation. Meeting future food demand while minimizing expansion of cultivated area primarily …


Genetic Variation In Geographical Populations Of Western And Mexican Corn Rootworm, A. L. Szalanski, R. L. Roehrdanz, D. B. Taylor, L. Chandler May 1999

Genetic Variation In Geographical Populations Of Western And Mexican Corn Rootworm, A. L. Szalanski, R. L. Roehrdanz, D. B. Taylor, L. Chandler

Department of Plant Pathology: Faculty Publications

Genetic variation in the nuclear rDNA ITS1 region of western corn rootworm, Diabrotica virgifera virgifera (WCR), and Mexican corn rootworm, D. v. zeae (MCR) was studied. Two sites were detected which differentiated WCR and MCR in the 642-base sequence. Polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) analysis of the first internal transcribed spacer region (ITS1) sequence revealed no variation within or among the twelve WCR and two MCR populations. PCR-RFLP of 75% of the mitochondrial DNA genome detected one significant polymorphic site out of the approximately 190 restriction sizes observed in WCR. The polymorphism did not differentiate geographical populations of …


1998 Oregon Winery Report, Oregon Agricultural Statistics Service, Homer K. Rowley, Ronald F. Kriesel, Douglas C. Marousek May 1999

1998 Oregon Winery Report, Oregon Agricultural Statistics Service, Homer K. Rowley, Ronald F. Kriesel, Douglas C. Marousek

Oregon Wine Board Documents

This statewide survey report on Oregon wineries covers crush, equivalent wine production, inventory and equivalent inventory, and sales. The report also contains some comparisons of data for 1997 and 1998. According to the report, wineries crushed 29% fewer grapes than the previous year, and wine inventory surpassed one million cases for the first time.


Cropwatch No. 99-10, May 21, 1999, Lisa Brown Jasa May 1999

Cropwatch No. 99-10, May 21, 1999, Lisa Brown Jasa

Crop Watch (1994–2005)

Inside

Field updates ………………….86

Wheat diseases few………………….86

Aphids in alfalfa………………….89

Canada thistle control………………….90

Timing wheat control………………….91

Scouting for stalk borers………………….92

Precipitation record………………….93

Crop report………………….93

Kansas wheat………………….93

Hard white wheat………………….94

Alfalfa weevil GDDs………………….94


Comparison Of Models To Estimate Genetic Effects For Weaning Weight Of Angus Cattle, J. Dodenhoff, L. Dale Van Vleck, D. E. Wilson May 1999

Comparison Of Models To Estimate Genetic Effects For Weaning Weight Of Angus Cattle, J. Dodenhoff, L. Dale Van Vleck, D. E. Wilson

Department of Animal Science: Faculty Publications

Weaning weights from nine sets of Angus field data from three regions of the United States were analyzed. Six animal models were used to compare two approaches to account for an environmental dam-offspring covariance and to investigate the effects of sire × herd-year interaction on the genetic parameters. Model 1 included random direct and maternal genetic, maternal permanent environmental, and residual effects. Age at weaning was a covariate. Other fixed effects were age of dam and a herd-year-management-sex combination. Possible influence of a dam’s phenotype on her daughter’s maternal ability was modeled by including a regression on maternal phenotype (f …


Myrica Californica Cham., Gordon C. Tucker May 1999

Myrica Californica Cham., Gordon C. Tucker

Specimens by Name

No abstract provided.


Viola Sororia Willd., Bob Edgin May 1999

Viola Sororia Willd., Bob Edgin

Specimens by Name

No abstract provided.


Acer X Freemanii E. Murray [Rubrum × Saccharinum], Bob Edgin May 1999

Acer X Freemanii E. Murray [Rubrum × Saccharinum], Bob Edgin

Specimens by Name

No abstract provided.


Acer Saccharinum L., Bob Edgin May 1999

Acer Saccharinum L., Bob Edgin

Specimens by Name

No abstract provided.


Parthenocissus Quinquefolia (L.) Planch., Bob Edgin May 1999

Parthenocissus Quinquefolia (L.) Planch., Bob Edgin

Specimens by Name

No abstract provided.


Claytonia Virginica L., Bob Edgin May 1999

Claytonia Virginica L., Bob Edgin

Specimens by Name

No abstract provided.