Phenotypic flexibility in digestive system structure and function in migratory birds and its ecological significance.

Birds during migration must satisfy the high energy and nutrient demands associated with repeated, intensive flight while often experiencing unpredictable variation in food supply and food quality. Solutions to such different challenges may often be physiologically incompatible. For example, increased food intake and gut size are primarily responsible for satisfying the high energy and nutrient demands associated with migration in birds.

Analysis of Vasodepressor Responses to Nociceptin and Nociceptin Analogs in the Systemic Vascular Bed of the Anesthetized Rabbit In Vivo.

Background: The heptadecapeptide nociceptin, also known as Orphanin FQ, is a recently discovered endogenous ligand for the opioid-like G-protein-coupled receptor ORL(1). Methods and Results: In the present study, responses to nociceptin, [Tyr(1)]-nociceptin, nociceptin-(2-17), nociceptin-(1-11), and nociceptin-(1-7) were compared in the systemic vascular bed of the rabbit. Nociceptin and [Tyr(1)]-nociceptin induced dose related decreases in systemic arterial pressure (SAP) when injected in doses of 1-30 nmol/kg intravenous (IV); in terms of relative vasodepressor activity, [Tyr(1)]-nociceptin and nocicpetin were similar in potency.

Posturographic performance in patients with the potential for secondary gain.

Objectives: To determine the incidence of nonorganic sway patterns on computerized dynamic posturography (CDP) among patients with potential secondary gain compared with patients without any obvious secondary gain.

Methods: A retrospective chart review of 100 patients who underwent clinical evaluation, audiometry, electronystagmography, and CDP was undertaken. Group 1 consisted of 50 patients who were randomly selected from a group who had pending lawsuits, worker's compensation claims, or disability claims.

Risk factors for hearing loss from meningitis in children: the Children's Hospital experience.

Objectives: To identify statistically significant risk factors for hearing loss in children with meningitis, determine the overall incidence of hearing loss in a large group of children with confirmed meningitis, and quantify the percentage of children with progressive or fluctuating hearing loss after meningitis.

Design: Retrospective analysis.

Patients And Other Participants: Four hundred thirty-two children admitted to the Children's Hospital, Birmingham, Ala, from January 1, 1985, to December 31, 1995, with the diagnosis of meningitis.

Endomorphin 1 and 2, the endogenous mu-opioid agonists, produce biphasic changes in systemic arterial pressure in the cat.

The endogenous peptides endomorphin 1 and 2 are newly isolated, potent, selective mu-opioid receptor agonists. In the present study, responses to the endomorphin peptides were investigated in the systemic vascular bed of the cat. Endomorphin 1 and 2 induced dose-related biphasic changes in systemic arterial pressure when injected in doses of 1-30 nmol/kg i.

Test of a digestion optimization model: effects of costs of feeding on digestive parameters.

We tested predictions of a chemical reactor model of digestion by manipulating the short-term costs of feeding and then measuring the effect on digestive parameters. We compared residence time of digesta and extraction efficiency of glucose in cold-acclimated waxwings (Bombycilla cedrorum) feeding ad lib. and in birds whose costs of feeding were increased through the addition of intervals of time when they received no food.

Test of a digestion optimization model: effect of variable-reward feeding schedules on digestive performance of a migratory bird.

Birds on migration often alternate between feeding and nonfeeding periods, in part because food resources may be patchily distributed and in part because birds on migration may adopt a risk-prone foraging strategy characterized by selection of variable rather than constant food rewards. Optimal digestion models predict that increases in intermeal interval like those encountered by some migratory birds should result in longer retention time of digesta and higher digestive efficiency if birds are maximizing their rate of energy intake. We tested these predictions by comparing residence time of digesta and extraction efficiency of lipid for captive yellow-rumped warblers (Dendroica coronata) feeding adlibitum and when we added intervals of time when the birds received no food.

Comparison of responses to rat and human adrenomedullin in the hindlimb vascular bed of the cat.

Responses to rat (r) adrenomedullin (ADM) and human (h) ADM were compared in the hindlimb vascular bed of the cat under conditions of controlled blood flow. Intra-arterial injections of rADM and hADM in doses of 0.03-1 nmol caused dose-related decreases in hindlimb perfusion pressure.

A test for passive absorption of glucose in yellow-rumped warblers and its ecological implications.

In an earlier study, we found that yellow-rumped warblers had in vitro active uptake rates of D-glucose that were only a few percent of the glucose absorption rate achieved at the whole-animal level. Here we used a pharmacokinetic technique to test whether a substantial amount of sugar can be absorbed passively. We used yellow-rumped warblers (Dendroica coronata), known for their seasonal frugivory, freely feeding on a synthetic mash formulated with naturally occurring concentrations of D-glucose.

Ondansetron usage in HIV positive patients: a pilot study on the control of nausea and vomiting in patients on high dose co-trimoxazole for Pneumocystis carinii pneumonia.

This was an open, single centre study, to evaluate the safety and efficacy of ondansetron in the treatment of co-trimoxazole associated nausea and vomiting in AIDS patients. Sixteen patients presenting with their first episode of HIV-associated Pneumocystis carinii pneumonia (PCP) on high dose co-trimoxazole were given ondansetron 8 mg orally, every 8 h. Measurements were made from data recorded by each patient on diary cards.

Polycrystalline CVD Diamond Films with High Electrical Mobility.

Advances in the deposition process have led to dramatic improvements in the electronic properties of polycrystalline diamond films produced by chemical vapor deposition (CVD). It is now possible to produce CVD diamond with properties approaching those of IIa natural diamonds. The combined electron-hole mobility, as measured by transient photoconductivity at low carrier density, is 4000 square centimeters per volt per second at an electric field of 200 volts per centimeter and is comparable to that of the best single-crystal IIa natural diamonds.

Histological and electron microprobe studies of mineralisation in aluminium-related osteomalacia.

Aims: To determine a possible mechanism to explain the presence of aluminium lines within fully calcified bone in aluminium-related osteomalacia.

Methods: Fifty five bone cases shown by bone biopsy to be aluminium-related osteomalacia were studied. In 38 specimens aluminium lines were identified within calcified bone by means of the Aluminon stain and a characteristic form of patchy mineralisation was seen within thickened osteoid seams.

Effects of stimulation on the ultrastructure and Na, K, Cl composition of the fundus of the rat plantar sweat gland.

Initial stimulation of the rat plantar sweat gland with pilocarpine caused a variable degree of distension of the apical membrane of the secretory cell. This appeared to be a process of filtration of secretory cell cytoplasm through the apical terminal web. Further stimulation resulted in luminal dilatation, cytoplasmic depletion, and morbidity of some cells.

The effects of thermally-induced activity in vivo upon the ultrastructure and Na, K and Cl composition of the epithelial cells of sweat glands from patients with cystic fibrosis.

The secretory cells of the fundus of sweat glands from cystic fibrosis (CF) patients had higher Na and Cl contents and showed more granule depletion, cellular disruption and dilated intercellular canaliculi than normal. The cells of the coiled duct also had higher cytoplasmic levels of Na and Cl but were structurally normal. Thermal stimulation produced ultrastructural changes in the CF fundus comparable to normal, including further dilatation of the basolateral clefts, but did not induce the marked changes in the coiled duct which normally occur.

Effects of topically-applied antiperspirant on sweat gland function.

In subjects exposed to a hot environment, short-term topical pretreatment with aluminium zirconium tetrachlorhydrate delayed the onset of visible sweating although it failed to prevent the response. The delay was considered most probably to be due to the occlusive action, in the duct within the upper epidermis, of aluminium-containing conglomerates, which disappear after continuous sweating. However, microanalytical evidence indicated that ionic transport within the fundus secretory cells was also modified.

Abnormal polarity of thunderclouds grown from negatively charged air.

Experiments were carried out in New Mexico to determine whether the electrification processes that lead to the formation of lightning in clouds are influenced by the polarity of the charges in the air from which the clouds grow. The normal, positive space charge in the sub-cloud air was reversed by negative charge released from an electrified wire, suspended across a 2-kilometer-wide canyon. On more than four occasions when the clouds over the wire grew and became electrified, they were of abnormal polarity with dominant positive charges instead of the usual negative charges in the lower part of the cloud.

Preparation of cryosections with a modified Sorvall MT2B ultramicrotome and cryoattachment.

The Sorvall MT2B ultramicrotome and cryoattachment were modified to extent the duration of cutting and to overcome problems in tissue preparation. Microtome and cryochamber were encased and surrounded by an atmosphere of dry nitrogen gas at room temperature. A specially designed cold block sited within the box close to the microtome enabled tissues to be trimmed at low temperatures in the dry environment.

Issues in replicating the trauma--Stren conversion.

The Trauma--Stren (T-S) conversion procedure was examined at a large state university and the construct related to personality and cognitive process variables. Significantly more respondents reported T-S conversion than in the original studies. Conversion was not significantly correlated with personal variables.