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Full-Text Articles in Biology

The Effects Of Stress On The Blood Calcium Level In The Male White Rat (Rattus Norvegicus), Howard Perry Cobb Aug 1985

The Effects Of Stress On The Blood Calcium Level In The Male White Rat (Rattus Norvegicus), Howard Perry Cobb

Master's Theses

THE EFFECTS OF STRESS ON THE BLOOD CALCIUM LEVEL IN THE MALE WHITE RAT (Rattus norvegicus) by Howard Perry Cobb I I I was writ ten as part of the requirements for a Master of Science degree in Biology at the University of Richmond (May, 1985). The present experiment was designed to determine whether parathyroid hormone (PTH) can be considered a "stress" hormone. Parathyroidectomized (PX) male rats (160-200 g) were injected with 10, 20, or 30 USP units of PTH per 100 g body weight and subjected to confinement/UHF stress for a 1.5-h period. Serum calcium levels of these PX …


Atp Defendent Na+ Transport And The Characterization Of Na+ / Nh4+ Exchange In Basolateral Vesicles Of The Blue Crab, Callinectes Sapidus, Gill, Linda Ann Fuhrman Aug 1985

Atp Defendent Na+ Transport And The Characterization Of Na+ / Nh4+ Exchange In Basolateral Vesicles Of The Blue Crab, Callinectes Sapidus, Gill, Linda Ann Fuhrman

Master's Theses

ATP dependent Na+ transport was denonstrated in purified ba.solateral vesicles of the blue crab (Callinectes sapidus) gill. Active Na+ uptake was dependent upon the intravesicular presence of either K+ or NH; as a counterion. Final membrane preparations consist of inside-out basolateral vesicles, evidenced by intravesicular ouabain (1 rrM) and extravesicular vanadate (1 rnM) 22Na + uptake inhibition. Na+/NH4+exchange rates were investigated by detennining the NH; concentration in the recovered extravesicular nedium and by using the kinetic capabilities of a DU7 spectrophotareter. These purified basolateral membranes, rich in Na+,K+ …


Anatomy And Systematics Of Penthorum L., Melanie Lynn Haskins Aug 1985

Anatomy And Systematics Of Penthorum L., Melanie Lynn Haskins

Master's Theses

The genus Penthorum L. consists of two species of perennial herbs, P. sedoides of eastern North America and P. chinense of eastern Asia. Penthorum has long be.en considered intermediate between crassulaceae and Saxifragaceae. An anatomical study of both species was undertaken to contribute to a better understanding of the relationships of these plants. Prominent anatomical features of Penthorum include: an aerenchymatous cortex and closely-spaced collateral vascular bundles of stems; one-trace unilacunar nodes; brochidodromous venation, rosoid teeth bearing hydathodes, and anomocytic stomata of leaves; angular vessel elements with many-barred scalariform perforation plates and alternate to scattered intervascular pits; thin-walled non-septate fiber-tracheids; …


An Electrophoretic Analysis Of The Genetic Relationship Between Etheostoma Nigrum And Etheostoma Olmstedi (Percidae: Etheostomatini) In The James River Drainage Of Virginia, John Stuart Prince Jr. Aug 1985

An Electrophoretic Analysis Of The Genetic Relationship Between Etheostoma Nigrum And Etheostoma Olmstedi (Percidae: Etheostomatini) In The James River Drainage Of Virginia, John Stuart Prince Jr.

Master's Theses

Etheostoma nigrum Rafinesque 1820, the Johnny darter ranges from Alabama to the Hudson Bay and from Colorado east to the Atlantic slope in the James, Roanoke, Tar and Neuse Rivers. Etheostoma olmstedi Storer 1842, the tesselated darter, is restricted to the east coast in the Atlantic and Lake Ontario drainage. In the James and Roanoke River systems in Virginia E. nigrum occupies the piedmont and montane regions whereas E. olmstedi primarily inhabits the coastal plain. The relationship between the morphologically similar species of darters (subgenus Boleosoma) is controversial and has been investigated by several authors. Stone (1947), using multiple character …


Gametogenesis En Chthonerpeton Indistinctum (Gymnophiona: Typhlonectidae), Rafael O. De Sá, Nibia Berois Jan 1985

Gametogenesis En Chthonerpeton Indistinctum (Gymnophiona: Typhlonectidae), Rafael O. De Sá, Nibia Berois

Biology Faculty Publications

RESUMEN:

Histológicamente, las gónadas de Chthonerpeton indistinctum son similares a las ya descritas para otras especies del orden Gymnophiona. Los lóbulos testiculares se hallan compartimentados en unidades estructurales denominadas lóculos. La espermatogénesis ocurre en cistos sincrónicos de células germinales. Durante la espermiogénesis se identifican cuatro estados consecutivos de desarrollo: 1) cistos de espermátidas redondeadas; 2) cistos de espermátidas arrifionadas; 3) cistos de espermátidas bastoniformes y 4) espermátidas en ramillete.

El análisis histológico de los ovarios mostró la presencia de tres estados en la maduración de los folículos ováricos. Estas etapas pueden ser identificadas de acuerdo a: 1) ubicación del folículo …


Estructura Del Ovario De Chthonerpeton Indistinctum (Reinhardt Y Lutken, 1862) (Amphibia: Gymnophiona) Durante La Gestación, Rafael O. De Sá, Nibia Berois Jan 1985

Estructura Del Ovario De Chthonerpeton Indistinctum (Reinhardt Y Lutken, 1862) (Amphibia: Gymnophiona) Durante La Gestación, Rafael O. De Sá, Nibia Berois

Biology Faculty Publications

La morfología e histología del ovario para varias especies del orden Gymnophiona ha sido reportada por Wake (1968, J. Morphol. 126, 291) y para C. indistinctum por los autores (1984, XXIV Reunión de Comunicaciones, Soc. Zool. Uruguay).

Continuando con los estudios sobre el aparato genital de esta especie vivípara, se presenta ahora la estructura del ovario durante la gestación.

Se procesaron con fines histológicos, ovarios de dos hembras grávidas colectadas en las costas de los Dep. Montevideo y San José en abril, 1983. El número de ejemplares trabajados es muy reducido dado lo difícil que resulta su colecta …


Morfología Y Funciones Del Conducto De Müller De Chthonerpeton Indistinctum (Reinhardt Y Lutken, 1862) (Amphibia: Gymnophiona) En Relación Con Los Mecanismos Reproductivos De La Especie, Nibia Berois, Rafael O. De Sá Jan 1985

Morfología Y Funciones Del Conducto De Müller De Chthonerpeton Indistinctum (Reinhardt Y Lutken, 1862) (Amphibia: Gymnophiona) En Relación Con Los Mecanismos Reproductivos De La Especie, Nibia Berois, Rafael O. De Sá

Biology Faculty Publications

El orden Gymnophiona comprende anfibios ápodos, ciegos, de hábitos cavícolas y acuáticos. Como consecuencia de estos hábitos resulta muy difícil su colecta, lo cual redunda en un escaso conocimiento de la biología del orden y sobre las relaciones filogenéticas del mismo.

Una de las características más particulares del grupo se refiere a la modalidad reproductora, ya que aproximadamente el 50% de las especies presentan viviparidad y la totalidad de ellas tienen fecundación interna. Es por esta razón que el estudio del aparato reproductor ha sido encarado por diversos autores, en especial por Wake (1968, J. Morphol. 126: 291) con una …


Description Of The Form Of Wing-Flashing Behavior In Northern Mockingbirds (Mimus Polyglottos), Lyn M. Harper, Kathryn J. Schneider Jan 1985

Description Of The Form Of Wing-Flashing Behavior In Northern Mockingbirds (Mimus Polyglottos), Lyn M. Harper, Kathryn J. Schneider

Honors Theses

The purpose of this study was to describe the form and location of wing-flashing behavior in mockingbirds and to identify differences in flashing between young and adult birds through film analysis techniques and observation. Subjects consisted of 50 mockingbirds from the University of Richmond campus. Analyses of the data suggested that there were three types of wing-flashes based on degree of wing extension. Flashes were most likely to occur in direct sunlight and in grass. No significant differences in the form of flashes between adult and juvenile mockingbirds were found. It is hoped that this study will provide insight into …


The Effect Of Bilateral Adrenalectomy On The Electrocardiogram Of Meriones Unguiculatus, Jeff A. Brown Jan 1985

The Effect Of Bilateral Adrenalectomy On The Electrocardiogram Of Meriones Unguiculatus, Jeff A. Brown

Honors Theses

The effects of adrenalectomy on the heart rate and electrical potentials of the heart of the Mongolian gerbil were studied (using an EKG) in an attempt to determine in hyperkalemia is the cause of its short survival time following adrenal ablation.


The Distribution Of The Ctenophore, Mnemiopsis Leidyi (A. Agassiz), In A Vertical Thermal Gradient, James J. Leder Iii Jan 1985

The Distribution Of The Ctenophore, Mnemiopsis Leidyi (A. Agassiz), In A Vertical Thermal Gradient, James J. Leder Iii

Honors Theses

The distribution of organisms in an estuary is affected by a plethora of environmental factors. The ctenophore, Mnemiopsis leidyi, is found to exists over a wide range of these factors, temperature and salinity in particular, allowing it to occupy the estuary year round and make use of low salinity areas unavailable to most marine organisms.