15,775 research outputs found
Ultradian, circadian and seasonal rhythms in cortisol secretion and adrenal responsiveness to ACTH and yarding in unrestrained red deer (Cervus elaphus) stags
Seasonal changes in the activity and responsiveness of the adrenal gland in red deer (Cervus elaphus) stags were quantified by measuring 24 h endogenous cortisol secretory profiles and plasma cortisol responses to either administration of exogenous ACTH or a standardised stressor during November (period of velvet growth), February (pre-rut), April (mid-rut) and July (post-rut) (southern hemisphere) using a remote blood sampling device (DracPac). Ultradian rhythms in the concentration of plasma cortisol were observed resulting from the episodic secretion of cortisol from the adrenal cortex at a mean rate of 0.8 pulses/h. Circadian rhythms in plasma cortisol concentrations were also found in 11 out of the 20 complete 24 h profiles (mean amplitude, 3.8+/-1.4 ng/ml). Seasonal rhythms in mean 24 h plasma cortisol concentrations and cortisol pulse parameters were also observed. Mean 24 h plasma cortisol concentrations were higher in November (12.5+/-1.0 ng/ml) than in February (6.3+/-1.0 ng/ml), April (4.0+/-1.0 ng/ml) or July (4.2+/-1. 0 ng/ml). Cortisol pulse height, nadir and amplitude were all significantly higher in November than at other times of the year (P<0.01). Peak cortisol concentrations following infusion of ACTH(1-24) (0.04 IU kg(-1)) were higher (P<0.05) in November (55.8+/-2.7 ng/ml) and lower (P<0.001) in April (33.7+/-1.8 ng/ml) than those in February and July (48.7+/-2.0 ng/ml and 45.4+/-2.0 ng/ml respectively). The area under the cortisol response curve was significantly smaller (P<0.05) in April (266.6+/-15.3 ng/ml/190 min) than at other times of the year (February, 366.1+/-15.3 ng/ml/190 min; July, 340.7+/-15.3 ng/ml/190 min and November, 387.8+/-21.2 ng/ml/190 min). These data demonstrate that the adrenal gland of the red deer stag exhibits ultradian, circadian and seasonal rhythms in activity, and that its responsiveness to ACTH varies with season. November, a period of reproductive quiescence in the southern hemisphere, with new antler growth and rapid weight gain, is associated with higher mean plasma cortisol concentrations and a greater responsiveness to exogenous ACTH. In contrast, the breeding season is associated with lower adrenal activity and responsiveness
Rapid, solid-phase based automated analysis of chromatin structure and transcription factor occupancy in living eukaryotic cells
Transcription factors, chromatin components and chromatin modification activities are involved in many diseases including cancer. However, the means by which alterations in these factors influence the epigenotype of specific cell types is poorly understood. One problem that limits progress is that regulatory regions of eukaryotic genes sometimes extend over large regions of DNA. To improve chromatin structure–function analysis over such large regions, we have developed an automated, relatively simple procedure that uses magnetic beads and a capillary sequencer for ligation-mediated-PCR (LM-PCR). We show that the procedure can be used for the rapid examination of chromatin fine-structure, nucleosome positioning as well as changes in transcription factor binding-site occupancy during cellular differentiation
Bald Eagles at the Savanna Army Depot
Eagle Valley Environmentalists Technical Report #SADE-81, Research Report conducted
December 1980 - March 1981, under a contract with the United States Arm
Weight changes following lower limb arthroplasty : a prospective observational study
The aim of this study was to assess patterns of weight loss/gain following total hip or knee joint replacement. Four hundred and fifty primary lower limb arthroplasty patients, where the current surgery was the last limiting factor to improved mobility, were selected. Over a one year period 212 gained weight (mean 5.03kg), 92 remained static, and 146 lost weight. The median change was a weight gain of 0.50Kg (p=0.002). All patients had a significant improvement in Oxford outcome scores. Hip arthroplasty patients were statistically more likely to gain weight than knee arthroplasty patients. A successful arthroplasty, restoring a patient's mobility, does not necessarily lead to subsequent weight loss. The majority of patients put on weight with an overall net weight gain. No adverse effect on functional outcome was noted
A Clash of Fundamental Rights: Conflicts Between the Fifth and Sixth Amendments in Criminal Trials
The United States Constitution\u27s Fifth and Sixth Amendments protect the rights of criminal defendants and witnesses. The Fifth Amendment\u27s privilege against self-incrimination protects witnesses from forced self-incrimination, and the Sixth Amendment provides criminal defendants with the right to cross-examine prosecution witnesses and to have compulsory process for obtaining witnesses. These fundamental rights conflict when a prosecution witness invokes the Fifth Amendment privilege on cross-examination or when a defense witness invokes the privilege on direct-examination. A grant of either use or transactional immunity would remove the potential for self-incrimination, but courts are split on whether they possess the authority to grant such immunity to defense witnesses. This Note examines the judicial approaches to resolving the conflicts between the Fifth and Sixth Amendment, and it analyzes the factors that favor and those that oppose a grant of immunity to defense witnesses. This Note concludes that defense witnesses should be granted use immunity whenever their testimony might be exculpatory
Internal wave observations off Isle Verte
A comparison is made between series of high frequency internal waves observed in the St. Lawrence estuary from an aircraft and in a field program at a later date. Wave generation is associated with the propagation of a warm surface front during each ebb flow. The number of waves, as evidenced by surface slicks, is thought to vary as does the stability of the upper layer of the water column
DESIGN: A CRITICAL NEED IN PEST-DAMAGE CONTROL EXPERIMENTS
The manner in which an experiment is conducted determines the inferences that can be made from the results of the analysis of the experiment. This paper emphasizes the critical need in pest-damage control (PDC) experiments for a detailed planning process (i.e., the design of experiments) by exampling improper designs that prohibit a researcher from making valid inferences about his hypotheses of interest. Emphasis is placed on identification of experimental units, determination of restrictions on the randomization procedure, and specification of treatment forms of pest control materials. A list of some specific actions to strengthen PDC experiments is given
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