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2000

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Articles 2311 - 2340 of 2418

Full-Text Articles in Life Sciences

A Record Large Wolf, Canis Lupus, Pack In Minnesota, L. David Mech Jan 2000

A Record Large Wolf, Canis Lupus, Pack In Minnesota, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

This report documents a pack of 22-23 Wolves (Canis lupus) in central Minnesota. This is larger than the largest pack previously observed on the mainland in the midwestern U.s. during 650 wolf pack-years. Because this record-large pack preyed on White-tailed Deer (Odocoileus virginianus), one of the Wolfs smaller prey, it is evidence that pack size and prey size are not tightly related. It also indicates the size that Wolf packs can attain in the area if fully protected from human persecution.


Lack Of Reproduction In Muskoxen And Arctic Hares Caused By Early Winter?, L. David Mech Jan 2000

Lack Of Reproduction In Muskoxen And Arctic Hares Caused By Early Winter?, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

A lack of young muskoxen (Ovibos moschatus) and arctic hares (Lepus arcticus) in the Eureka area of Ellesmere Island, Northwest Territories (now Nunavut), Canada, was observed during summer 1998, in contrast to most other years since 1986. Evidence of malnourished muskoxen was also found. Early winter weather and a consequent 50% reduction of the 1997 summer replenishment period appeared to be the most likely cause, giving rise to a new hypothesis about conditions that might cause adverse demographic effects in arctic herbivores.

Durant l’été 1998, et ce, à la différence de la plupart des années depuis …


Accuracy And Precision Of Estimating Age Of Gray Wolves By Tooth Wear, Philip S. Gipson, Warren B. Ballard, Ronald M. Nowak, L. David Mech Jan 2000

Accuracy And Precision Of Estimating Age Of Gray Wolves By Tooth Wear, Philip S. Gipson, Warren B. Ballard, Ronald M. Nowak, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

We evaluated the accuracy and precision of tooth wear for aging gray wolves (Canis lupus) from Alaska, Minnesota, and Ontario based on 47 known-age or known-minimum-age skuIIs. Estimates of age using tooth wear and a commercial cementum annuli-aging service were useful for wolves up to 14 years old. The precision of estimates from cementum annuli was greater than estimates from tooth wear, but tooth wear estimates are more applicable in the field. We tended to overestimate age by 1-2 years and occasionaIIy by 3 or 4 years. The commercial service aged young wolves with cementum annuli to within …


Agroforestry In The United States: Research And Technology Transfer Needs For The Next Millennium Jan 2000

Agroforestry In The United States: Research And Technology Transfer Needs For The Next Millennium

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

If society's needs and aspirations for forestderived goods, services, and amenities truely are to be met, we must find ways of augmenting traditional forestry by gleaning some portion of these benefits from agricultural lands. For example: windbreaks, riparian forest buffers, hybrid poplar trees, farm woodlots, and grazing/timber systems.


Viability Of Piping Plover Charadrius Melodus Metapopulations, Jonathan H. Plissner, Susan M. Haig Jan 2000

Viability Of Piping Plover Charadrius Melodus Metapopulations, Jonathan H. Plissner, Susan M. Haig

United States Geological Survey: Staff Publications

The meta-population viability analysis package, vortex, was used to examine viability and recovery objectives for piping plovers Charadrius melodus, an endangered shorebird that breeds in three distinct regions of North America. Baseline models indicate that while Atlantic Coast populations, under current management practices, are at little risk of near-term extinction, Great Plains and Great Lakes populations require 36% higher mean fecundity for a significant probability of persisting for the next 100 years. Meta-population structure (i.e. the delineation of populations within the meta-population) and inter-population dispersal rates had varying effects on model results; however, spatially-structured meta-populations exhibited lower viability than …


Direct And Indirect Parametrization Of A Localized Model For The Mountain Pine Beetle — Lodgepole Pine System, Zy Biesinger, James Powell, Barbara Bentz, Jesse Logan Jan 2000

Direct And Indirect Parametrization Of A Localized Model For The Mountain Pine Beetle — Lodgepole Pine System, Zy Biesinger, James Powell, Barbara Bentz, Jesse Logan

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

The dynamic interaction between mountain pine beetles (MPB) and one of its hosts is reviewed briefly. The ‘local’ projection of a partial differential equation model describing this interaction is employed in model parameter estimation. Methods and assumptions for estimating non-fitted parameter values are given. Assigning values to non-fitted parameters, direct and indirect parametrization techniques are employed to estimate remaining parameter values. The indirect method is quickly and easily applied to many data sets but requires some assumptions and model simplifications. The direct method requires fewer assumptions but is computationally intensive. The results of these two techniques are compared and evaluated.


Aquatic Dissipation Of The Herbicide Triclopyr In Lake Minnetonka, Minnesota, Kurt D. Getsinger, David G. Petty, John D. Madsen, John G. Skogerboe, Bruce A. Houtman, William T. Haller, Alison M. Fox Jan 2000

Aquatic Dissipation Of The Herbicide Triclopyr In Lake Minnetonka, Minnesota, Kurt D. Getsinger, David G. Petty, John D. Madsen, John G. Skogerboe, Bruce A. Houtman, William T. Haller, Alison M. Fox

United States Army Corps of Engineers, Omaha District

A study of the aquatic fate of the triethylamine salt of triclopyr (3,5,6-trichloro-2- pyridinyloxyacetic acid) was conducted in three bays of Lake Minnetonka, Minnesota. Triclopyr is under review by the US Environmental Protection Agency as a selective aquatic herbicide. The primary purpose of this study was to determine dissipation rates of the parent active ingredient, triclopyr, and its major metabolites, 3,5,6-trichloropyridinol (TCP) and 3,5,6-trichloro-2-methoxypyridine (TMP) in selected matrices including water, sediment, plants, finfish and shellfish. Two 6.5- ha plots dominated by the weedy species Eurasian watermilfoil (Myriophyllum spicatum L) were treated with triclopyr-triethylammonum at a rate of 2.5mg AE liter …


The Systematics Of The Genus Trichinella With A Key To Species, K. D. Murrell, J. Ralph Lichtenfels, Dante S. Zarlenga, E. Pozio Jan 2000

The Systematics Of The Genus Trichinella With A Key To Species, K. D. Murrell, J. Ralph Lichtenfels, Dante S. Zarlenga, E. Pozio

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The authors review the major biological, biochemical, and molecular characters that are used to distinguish the seven Trichinella species (T. spiralis, T. nativa, T. britovi, T. pseudospiralis, T. murrelli, T. nelsoni, T. papuae) and three genotypes whose taxonomic status is yet uncertain (T-6, T-8, T-9). A comparison of host specificity, morphology, reproductive abilities, nurse cell development and freeze resistance is presented, along with useful biochemical and molecular markers. Finally, this information is used to construct a diagnostic key for the species. A phylogenetic classification of the species is needed.


Meningeal Worm In Deer From Western Nebraska, David W. Oates, Mauritz C. Sterner, Ed Boyd Jan 2000

Meningeal Worm In Deer From Western Nebraska, David W. Oates, Mauritz C. Sterner, Ed Boyd

Harold W. Manter Laboratory of Parasitology: Faculty Publications

One hundred seventy-eight whitetailed deer (Odocoileus virginianus) and 275 mule deer (Odocoileus hemionus) collected from locker plants in the western 2/3 of Nebraska (USA) in November 1997 were examined for the meningeal worm (Parelaphostrongylus tenuis). Parelaphostrongylus tenuis was identified in 17 (10%) of 168 white-tailed deer and in one (<1%) of 273 mule deer. This is the first naturally occurring infection of P. tenuis recorded in a mule deer.


Coccidia (Apicomplexa: Eimeriidae) Of The Mammalian Order Insectivora, Donald W. Duszynski, Steve J. Upton Jan 2000

Coccidia (Apicomplexa: Eimeriidae) Of The Mammalian Order Insectivora, Donald W. Duszynski, Steve J. Upton

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The coccidia (protistan phylum Apicomplexa Levine, 1970) comprise a large group of obligate intracellular parasites commonly found in all classes of vertebrate hosts and in some invertebrates. This review focuses on those species within the Eimeriidae because they are among the most prevalent and speciose of all parasite groups, and there is no taxonomic summation currently available for those species that infect insectivores. All published species descriptions in the genera Cyclospora, Eimeria and Isospora that infect insectivores are reviewed and evaluated. Some of the named species are invalid, either because rules concerning the naming of new species (International …


Phylogeny Of The Ascaridoidea (Nematoda: Ascaridida) Based On Three Genes And Morphology: Hypotheses Of Structural And Sequence Evolution, Steven A. Nadler, Deborah S. S. Hudspeth Jan 2000

Phylogeny Of The Ascaridoidea (Nematoda: Ascaridida) Based On Three Genes And Morphology: Hypotheses Of Structural And Sequence Evolution, Steven A. Nadler, Deborah S. S. Hudspeth

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Ascaridoid nematodes parasitize the gastrointestinal tract of vertebrate definitive hosts and are represented by more than 50 described genera. We used 582 nucleotides (83% of the coding sequence) of the mitochondrial gene cytochrome oxidase subunit 2, in combination with published small- and large-subunit nuclear rDNA sequences (2,557 characters) and morphological data (20 characters), to produce a phylogenetic hypothesis for representatives of this superfamily. This combined evidence phylogeny strongly supported clades that, with 1 exception, were consistent with Fagerholm’s 1991 classification. Parsimony mapping of character states on the combined evidence tree was used to develop hypotheses for the evolution of morphological, …


Phylogenetic Relationships Among Species Of Contracaecum Railliet & Henry, 1912 And Phocascaris Høst, 1932 (Nematoda: Ascaridoidea) Based On Nuclear Rdna Sequence Data, Steven A. Nadler, S. D'Amelio, H. P. Fagerholm, B. Berland, L. Paggi Jan 2000

Phylogenetic Relationships Among Species Of Contracaecum Railliet & Henry, 1912 And Phocascaris Høst, 1932 (Nematoda: Ascaridoidea) Based On Nuclear Rdna Sequence Data, Steven A. Nadler, S. D'Amelio, H. P. Fagerholm, B. Berland, L. Paggi

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Nuclear-encoded large-subunit ribosomal DNA sequences were used to infer a phylogenetic hypothesis for 17 taxa (16 nominal species) of the genera Contracaecum and Phocascaris. Phylogenetic trees based on these data have been used to assess the validity of the taxonomic distinction between these genera, which was based on the presence or absence of certain structural features, rather than on explicit hypotheses of evolutionary history. Phylogenetic hypotheses based on parsimony, likelihood, and neighbor-joining analyses of these sequence data strongly support the hypothesis that species of Phocascaris are nested within the clade of Contracaecum species hosted by phocid seals, and are …


A Cox2 Molecular Phylogeny Of The Peronosporomycetes, Deborah S.S. Hudspeth, Steven A. Nadler, Michael E.S. Hudspeth Jan 2000

A Cox2 Molecular Phylogeny Of The Peronosporomycetes, Deborah S.S. Hudspeth, Steven A. Nadler, Michael E.S. Hudspeth

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The evolutionary history of the mitochondrial COX2 locus has been used to infer the phylogenetic relationships among 15 peronosporomycete and a hyphochytriomycete species. This molecular phylogenetic analysis at both the ordinal and generic levels provides strong evidence for the recognition of the Saprolegniomycetidae and the Peronosporomycetidae as natural groups, and for the monophyly of the Saprolegniales, Leptomitales and Pythiales. A three amino acid insertion/deletion event (indel) has been identified as a putative synapomorphy for the Saprolegniales. Parsimony mapping of 12 morphological and biochemical characters on the COX2 molecular phylogeny yields an hypothesis for peronosporomycete ancestral states and shared-derived features.


Relationships Of Nematodirus Species And Nematodirus Battus Isolates (Nematoda: Trichostrongyloidea) Based On Nuclear Ribosomal Dna Sequences, Steven A. Nadler, Eric P. Hoberg, Deborah S.S. Hudspeth, Lora G. Rickard Jan 2000

Relationships Of Nematodirus Species And Nematodirus Battus Isolates (Nematoda: Trichostrongyloidea) Based On Nuclear Ribosomal Dna Sequences, Steven A. Nadler, Eric P. Hoberg, Deborah S.S. Hudspeth, Lora G. Rickard

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Nuclear ribosomal sequence data from the internal transcribed spacers (ITS-1 and ITS-2), 5.8S subunit, and regions of the 18S and 28S genes were used to investigate sequence diversity among geographic samples of Nematodirus battus, and to infer phylogenetic relationships among Nematodirus species. Phylogenetic analysis of these data yielded strong support for relationships among species, depicting Nematodirus helvetianus and Nematodirus spathiger as sister-taxa and a clade of these two species and Nematodirus filicollis. This tree is consistent with caprine bovids as ancestral hosts, with a subsequent host shift to Bovinae in N. helvetianus. Eleven of fourteen N. battus sequences …


Archaeoparasitology, Karl Reinhard Jan 2000

Archaeoparasitology, Karl Reinhard

Karl Reinhard Publications

The field devoted to the identification of parasite remains in the archaeological record and the reconstruction of past human-parasite interactions. Parasitic disease has always been a major problem. Recent summaries of the prevalence of parasitic diseases in the world today show that there are 4.5 billion infections with all species of parasitic worm, 1 billion infections with giant intestinal roundworm (Ascaris lumbricoides), 750,000,000 infections with whipworms (Trichuris trichiura), 900,000,000 infections with hookworm (Ancylostoma duodenale and Necator americanus), 657,000,000 infections with filarial worms, 200,000,000 with blood flukes (schistosome species), and 489,000,000 infections with malaria. These infections cause between 1,590,000 to 3,130,000 …


Coprolite Analysis: The Analysis Of Ancient Human Feces For Dietary Data, Karl Reinhard Jan 2000

Coprolite Analysis: The Analysis Of Ancient Human Feces For Dietary Data, Karl Reinhard

Karl Reinhard Publications

Although archaeological fieldwork is hot and dirty, the most “earthy” side of the discipline is the laboratory analysis of coprolites. Each coprolite contains the remains of one to several actual meals eaten in prehistory, and analysis of many coprolites provides a picture of ancient diet that is unique in accuracy.

The term coprolite originally referred to fossilized feces in paleontological context. In archaeology, the term broadened to refer to any formed fecal mass, including mineralized, desiccated, or frozen feces and even the intestinal contents of mummies. Coprolites contain the remains of animals (parasites) that lived in the humans, the foods …


Life Cycle Of Calyptospora Funduli (Apicomplexa: Calyptosporidae), John W. Fournie, Wolfgang K. Vogelbein, Robin M. Overstreet, William E. Hawkins Jan 2000

Life Cycle Of Calyptospora Funduli (Apicomplexa: Calyptosporidae), John W. Fournie, Wolfgang K. Vogelbein, Robin M. Overstreet, William E. Hawkins

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The taxonomic status of the extraintestinal piscine coccidium Calyptospora funduli is based in part on its requirement of an intermediate host (the daggerblade grass shrimp Palaemonetes pugio). In the present study, grass shrimp fed livers of Gulf killifish (Fundulus grandis) infected with sporulated oocysts of C. funduli exhibited numerous sporozoites suspended in the intestinal contents when fresh squash preparations were examined by light microscopy. Using this method, sporozoites were not seen in intestinal epithelial cells of the grass shrimp or in any other cell types. Ultrastructural examination, however, revealed sporozoites in the cytoplasm of the gut basal …


Reproductive Biology Of Cobia, Rachycentron Canadum, From Coastal Waters Of The Southern United States, Nancy J. Brown-Peterson, Robin M. Overstreet, Jeffrey M. Lotz, James S. Franks, Karen M. Burns Jan 2000

Reproductive Biology Of Cobia, Rachycentron Canadum, From Coastal Waters Of The Southern United States, Nancy J. Brown-Peterson, Robin M. Overstreet, Jeffrey M. Lotz, James S. Franks, Karen M. Burns

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Reproductive biology of the cobia, Rachycentron canadum, is described from four coastal areas in the southern United States. Samples were obtained from recreational fishermen between December 1995 and November 1997 from the southeastern United States (Morehead City, NC, to Cape Canaveral, FL), the eastern Gulf of Mexico (Ft. Myers to Crystal River, FL), the north-central Gulf of Mexico (Destin, FL, to Chandeleur Islands, LA) and the western Gulf of Mexico (Port Aransas, TX). Histological evidence of spawning occurred from April through September in all areas. Some female cobia (17-32%) throughout the Gulf of Mexico had spent or regressed ovaries …


Hydrolase And Oxido-Reductase Activities In Diuraphis Noxia And Rhopalosiphum Padi (Hemiptera: Aphididae), Xinzhi Ni, Sharron S. Quisenberry, Saowaluck Pornkulwat, James Lester Figarola, Steven R. Skoda, John E. Foster Jan 2000

Hydrolase And Oxido-Reductase Activities In Diuraphis Noxia And Rhopalosiphum Padi (Hemiptera: Aphididae), Xinzhi Ni, Sharron S. Quisenberry, Saowaluck Pornkulwat, James Lester Figarola, Steven R. Skoda, John E. Foster

Department of Entomology: Faculty Publications

Four hydrolases and five oxido-reductases were examined using native stacking polyacrylamide gel electrophoresis. Homogenate of Russian wheat aphid, Diuraphis noxia (Mordvilko), bird cherry-oat aphid, Rhopalosiphum padi (L.), "Arapahoe" (aphid-susceptible) and "Halt" (aphid-resistant) wheat, Triticum aestivum L., and powdery mildew-infected Erysiphe graminis DC. ex Merat f. sp. tritici Em. Marchal, Arapahoe wheat leaves were assayed for enzyme activities. Pectinesterase, polygalacturonase (or pectinase), cellulase, and amylase activities were examined in the hydrolase group. Catalase, peroxidase, catechol oxidase, superoxide dismutase, and ascorbate oxidase activities were examined in the group of oxido-reductases. The two aphid species had the same hydrolases but different oxido-reductases. Although …


Salinity And Shade Preferences Result In Ovipositional Differences Between Sympatric Tiger Beetle Species, W. Wyatt Hoback, Douglas A. Golick, Tina Marie Svatos, Stephen M. Spomer, Leon G. Higley Jan 2000

Salinity And Shade Preferences Result In Ovipositional Differences Between Sympatric Tiger Beetle Species, W. Wyatt Hoback, Douglas A. Golick, Tina Marie Svatos, Stephen M. Spomer, Leon G. Higley

Department of Entomology: Faculty Publications

1. Adult tiger beetles of the genus Cicindela often co-occur within a habitat but larvae do not. Larvae are sedentary and form usually permanent burrows at the site of oviposition where they require 1-3 years for development.

2. To test niche partitioning based on ovipositional preference, the behavior of two sympatric salt marsh tiger beetles, Cicindela circumpicta and C. togata (Coleoptera: Cicindelidae), were examined.

3. In laboratory studies, female C. circumpicta and C. togata distinguished between experimental salinities, with the former preferring 4 parts per thousand (ppt) and the latter preferring 12 ppt. In the field, C. circumpicta larvae were …


Assessing Nuclear And Mitochondrial Dna Sequence Variation Within Steinernema (Rhabditida: Steinernematidae), Allen L. Szalanski, David B. Taylor, Peter G. Mullin Jan 2000

Assessing Nuclear And Mitochondrial Dna Sequence Variation Within Steinernema (Rhabditida: Steinernematidae), Allen L. Szalanski, David B. Taylor, Peter G. Mullin

Department of Entomology: Faculty Publications

DNA sequence analysis was used to characterize the nuclear ribosomal DNA ITS1 region and a portion of the COII and 16S rDNA genes of the mitochondrial genome from Steinernema entomopathogenic nematodes. Nuclear ITS1 nucleotide divergence among seven Steinernema spp. ranged from 6 to 22%, and mtDNA divergence among five species ranged from 12 to 20%. No intraspecific variation was observed among three S. feltiae strains. Phylogenetic analysis of both nuclear and mitochondrial DNA sequences confirms the existing morphological relationships of several Steinernema species. Both the rDNA ITS1 and mtDNA sequences were useful for resolving relationships among Steinernema taxa.


Biology And Ecology Of Rivulus Marmoratus: New Insights And A Review, D. Scott Taylor Jan 2000

Biology And Ecology Of Rivulus Marmoratus: New Insights And A Review, D. Scott Taylor

Ocean Engineering and Marine Sciences Faculty Publications

Rivulus marmoratus (Pisces: Aplocheilidae) is a small cyprinodontid indigenous to mangroves of the western tropical Atlantic. This species is well known as the only selffertilizing, hermaphroditic vertebrate, and populations normally consist of genetically diverse groups of homozygous clones. However, male fish are known from a few populations, and outcrossing and heterozygosity have been documented from two areas in Central America. Rivulus marmoratus also exhibits a number of behaviors and environmental tolerances unusual in fishes, and since the species is secretive, rare in some habitats and difficult to collect, knowledge of its natural history has been limited until recently. Within the …


Effect Of Spaceflight On The Isotonic Contractile Properties Of Single Skeletal Muscle Fibers In The Rhesus Monkey, Robert H. Fitts, Janell R. Romatowski, Cynthia A. Blaser, Lourdes J. De La Cruz, Gwen J. Gettelman, Jeffrey J. Widrick Jan 2000

Effect Of Spaceflight On The Isotonic Contractile Properties Of Single Skeletal Muscle Fibers In The Rhesus Monkey, Robert H. Fitts, Janell R. Romatowski, Cynthia A. Blaser, Lourdes J. De La Cruz, Gwen J. Gettelman, Jeffrey J. Widrick

Biological Sciences Faculty Research and Publications

No abstract provided.


Field Notes On The Biology Of The Long-Wattled Umbrellabird Cephalopterus Penduliger In West Ecuador., Karl S. Berg Jan 2000

Field Notes On The Biology Of The Long-Wattled Umbrellabird Cephalopterus Penduliger In West Ecuador., Karl S. Berg

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

La biología del Pajaro Paraguas Longipendulo Cephalopterus penduliger es quizas lo menos conocido del genero. A pesar de eso, lo consideraron una de las especies más amenzadas en el continente Sudamericano debido a la deforestación, caza y a un grado menor, la comercialización de las aves como mascotas. Entre febrero y octubre de 1998 yo observe C. penduliger a lo largo del período y 1.600 horas de observación en la Estación Biológica Jatun Sacha Bilsa, Provincia de Esmeraldas, Ecuador. Documente varios aspectos de las observaciones incluyendo un sonogramo de dos vocalizaciones, descripciones de comportamiento, forrageo y las primeras fotos de …


First Nesting Record Of Blue Jay (Cyanocitta Cristata) In Hidalgo County, Texas, Timothy Brush Jan 2000

First Nesting Record Of Blue Jay (Cyanocitta Cristata) In Hidalgo County, Texas, Timothy Brush

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

No abstract provided.


Ovipositional Behavior Of The 12-Spotted Lady Beetle, Coleomegilla Maculata: Choices Among Plant Species And Potential Factors Influencing Those Choices, Marisa Lynn Griffin Jan 2000

Ovipositional Behavior Of The 12-Spotted Lady Beetle, Coleomegilla Maculata: Choices Among Plant Species And Potential Factors Influencing Those Choices, Marisa Lynn Griffin

University of Kentucky Master's Theses

Coleomegilla maculata is a beneficial coccinellid commonly found in sweet cornfields in Kentucky. Previous work on C. maculata has shown an ovipositional preferencefor the weed Acalypha ostryaefolia, compared to three selected weed species and corn. Also, predation of C. maculata egg clusters on A. ostryaefolia was less compared toclusters on corn and the presence of A. ostryaefolia led to higher densities of C. maculata larvae on corn.

I determined C. maculata ovipositional preference among weed species in fieldtests using nine common weeds. I also examined ovipositional preference using just A.ostryaefolia and Abutilon theophrasti. I assessed the roles of …


Genomic Imprinting: A Specialized Form Of Generegulation, Fatma Fi̇li̇z Çoşkun Ari Jan 2000

Genomic Imprinting: A Specialized Form Of Generegulation, Fatma Fi̇li̇z Çoşkun Ari

Turkish Journal of Biology

Genomic imprinting is a process resulting in the preferential expression of certain genes depending on whether the genetic material has been inherited from the mother or the father. Many imprinted genes have been identified as having important roles in mammalian development, and the loss of imprints as well as non-imprinted alleles causes a variety of developmental abnormalities and pathological conditions in both mice and humans. In this article, the phenomenon of genomic imprinting, the developmental implications of imprinting and the molecular mechanisms proposed for this process are reviewed.


An Investigation On The Pollen Production Capacities And Germination Rates Of Some Strawberry Cultivars, Fatma Koyuncu, Hüdai̇ Yilmaz, M. Ati̇lla Aşkin Jan 2000

An Investigation On The Pollen Production Capacities And Germination Rates Of Some Strawberry Cultivars, Fatma Koyuncu, Hüdai̇ Yilmaz, M. Ati̇lla Aşkin

Turkish Journal of Agriculture and Forestry

This investigation was conducted to determine the pollen germination rates and the pollen production capacities of some strawberry cultivars grown in Van ecological conditions. The experiments were carried out at the Department of Horticulture, Faculty of Agriculture, University of Yüzüncü Yıl in 1997-1998. The examinations of pollen germinations were done in vitro by the 'agar in plate' method (0, 10, 15, and 20 % sucrose solutions with 1 % agar). The pollen production capacities were determined by the hemacytometric method. Seven strawberry cultivars (Cruz, Tufts, Brio, Tioga, Vista, Aliso and 216), which were tested in germination experiments, gave the best …


Isosteric Sorption Heat Determination For Some Starchy Grains, Serdar Özteki̇n, Yurtsever Soysal Jan 2000

Isosteric Sorption Heat Determination For Some Starchy Grains, Serdar Özteki̇n, Yurtsever Soysal

Turkish Journal of Agriculture and Forestry

InIn this study, isosteric sorption heat for 8 different starchy grains was determined by the application of the Clausius- Clapeyron equation to sorption isotherms. The latent heat of vaporisation of free water was not significantly different from the isosteric sorption heats of barley, durum wheat, oats, sorghum (31) and sorghum above 14% d.b. moisture content. There was no significant difference among the latent heat of vaporisation of free water and isosteric sorption heats of soft wheat, hard wheat and wheat (Waldron) above the 17% moisture content. Isosteric sorption heat of soft wheat was calculated to be 3341.5 kJ kg -1 …


Determining The Efficiency Of Forward-Sloped Bench Terraces On Soil Conservation: The Case Of The Aydın-Bozdoğan-Alamut Terracing Area, Alaetti̇n Taysun, Hali̇l Baki̇ Ünal, Altan Şahi̇n, Hasan Zafer Vurgun Jan 2000

Determining The Efficiency Of Forward-Sloped Bench Terraces On Soil Conservation: The Case Of The Aydın-Bozdoğan-Alamut Terracing Area, Alaetti̇n Taysun, Hali̇l Baki̇ Ünal, Altan Şahi̇n, Hasan Zafer Vurgun

Turkish Journal of Agriculture and Forestry

The study was carried out to determine the efficiency of forward-sloped bench terraces on soil conservation in the Aydın- Bozdoğan-Alamut terracing area. For this purpose, the shape specifications, and physical and chemical properties of the soil that belong to the sample terraces in the project area were determined and the factors of K and LS that are needed for calculating soil losses were are found through the Universal Soil Losses Equation. According to the evaluation, especially the determined factors of K and LS were higher for the sample terraces interfered with by farmers and this result shows that the probable …