Identification of a novel amide peptide, GLTPNMNSLFF-NH2, involved in the control of vas deferens motility in lymnaea stagnalis

Peptide messengers are crucial for the execution of male copulatory processes in the snail Lymnaea stagnalis. In this study, we report the purification of a novel peptide from the penis complex of L. stagnalis. This peptide enhances the contraction frequency and contraction amplitude of the vas deferens. Amino acid sequencing and mass spectrometry indicate that the primary structure is GLTPNMNSLFF-NH2. We propose that this amide peptide modulates the transfer rate of semen in the vas deferens.     

A criterion for joint optimization of identification and robustcontrol

A criterion for system identification is developed that is consistent with the intended use of the fitted model for modern robust control synthesis. Specifically, a joint optimization problem is posed which simultaneously solves the plant model estimate and control design, so as to optimize robust performance over the set of plants consistent with a specified experimental data set     

STZ-induced diabetes in mice and heme pathway enzymes. Effect of allylisopropylacetamide and alpha-tocopherol

We compared the systemic and regional hemodynamic effects of nifedipine and lisinopril in 26 elderly hypertensive patients with the use of the pulsed Doppler ultrasound technique. Nifedipine is a dihydropyridine calcium antagonist, and lisinopril is an angiotensin-converting enzyme inhibitor. The study had a single-blind crossover design: nifedipine and lisinopril were given for 8 weeks each after washout periods of 4 weeks. Both nifedipine and lisinopril significantly reduced mean arterial pressure to the same extent (P < .01); cardiac output remained unchanged in both nifedipine- and lisinopril-treated groups. Lisinopril increased renal flow significantly (P < .01), but nifedipine did not. Common carotid, vertebral, celiac, and superior mesenteric arterial and diaphragmatic and terminal aortic flows did not show a significant change with either nifedipine or lisinopril. The specific action of lisinopril on the thoracic aorta was a marked improvement of aortic compliance compared with nifedipine, which might be partly responsible for an increase in renal flow. Lisinopril may provide more desirable regional hemodynamic effects and additional benefits for elderly hypertensive patients.     

Estimating in situ exposure in the presence of acoustic nonlinearity

Evidence is presented for excess attenuation of pulsed ultrasound due to finite amplitude effects in water. Measurements on a modern scanner are used to demonstrate that linear derating can underestimate many exposure quantities, including all safety indices apart from the cranial thermal index. More appropriate methods for estimating in situ exposure are reviewed. A preferred procedure that requires exposure measurements to be made in water under "small signal" conditions is selected. A spectral index is defined that is proposed as an indicator of finite amplitude effects, where spectral index = 0.1 defines the threshold between nonlinear and quasi-linear conditions.     

Prevention of murine collagen-induced arthritis in the knee and ipsilateral paw by local expression of human interleukin-1 receptor antagonist protein in the knee

OBJECTIVE: To determine the efficacy of local human interleukin-1 receptor antagonist (HuIL-1Ra) gene therapy in murine collagen-induced arthritis (CIA). METHODS: DBA/1 mice were immunized against bovine type II collagen. Before the onset of arthritis, NIH/3T3 fibroblasts transfected with pMFG-IRAP were transplanted into the knee cavity. Normal NIH/3T3 cells served as controls. Paws were evaluated macroscopically for redness, swelling, and deformities during the course of arthritis. Swelling of the knee joints was measured by external gamma counting of 99mtechnetium accumulation in the joint. Paws and knee joints were dissected and processed for histologic studies to evaluate inflammation and cartilage destruction. RESULTS: The NIH/3T3 fibroblasts survived in the joint cavity of DBA mice for at least 7 days. The transduced cells expressed immunoreactive and bioactive HuIL-1Ra in the knee joint, and produced sufficient amounts to block the effect of 1 ng of recombinant murine IL-1alpha on chondrocyte proteoglycan synthesis. The onset of CIA was almost completely prevented in knee joints containing HuIL-1Ra-producing cells, whereas joints containing normal cells showed severe inflammation and destruction of cartilage. Moreover, onset of CIA in the draining joints (ipsilateral paws) of the HuIL-1Ra gene-bearing knees was also prevented. CONCLUSION: Local production of HuIL-1Ra in the knee was able to ameliorate the effects of IL-1 on cartilage and could prevent the onset of CIA not only in that knee, but also in the "draining" paw. This indicates the feasibility of gene transfer as a therapeutic approach to modulating arthritis.     

Effects of time-of-day and photoperiod phase shifts on voluntary ethanol consumption in rats

Two experiments were conducted to examine the circadian fluctuations in voluntary ethanol (ETOH) consumption in male Sprague-Dawley rats conditioned to consume ETOH in their homecage and exposed to photoperiod phase shifts equivalent to those experienced by humans. Using a maintenance concentration of 20% w/v ETOH, changes in homecage drinking in 42 rats were assessed after photoperiod phase shifts similar to those inducing "jet lag" in humans and after experimenter-induced "hangover." A single 8-hr photoperiod phase advance significantly increased ETOH intake for three consecutive days, and a single photoperiod phase-delay increased intake only on the day of the phase shift. Acute ETOH withdrawal significantly reduced the voluntary consumption of ETOH for two consecutive days. In a second group of 30 rats maintained to consume a lower concentration of 10% w/v ETOH, the long-term effects of "shift lag" initiated by repeated photoperiod phase shifting similar to those experienced by humans working under a rotating work schedule were examined. Significant increases in intake occurred over the 2-month testing period. The significant alterations in voluntary intake initiated by the shift work schedule was related to the significant changes in blood alcohol concentrations.     

Control system design and evaluation for robust autonomous rotorcraft guidance

This paper describes the design and performance analysis of a control system for rotorcraft with an emphasis on the requirements called for by autonomous guidance. To be able to track trajectories, such as those generated by a guidance system, a path following controller is used in combination with a velocity control augmentation. The path following system is motivated by nonlinear stability analysis. The velocity control augmentation follows a loop-shaping design for the inner-loop attitude control and a dynamic inversion velocity control design for the outer-loop. The identified model of the dynamics along with the uncertainties is used to determine the robustness and performance of the velocity control system. Finally, the paper presents a novel method to evaluate the overall performance of the control system in terms of the tracking error statistics. These results are then used to determine a tracking error model, which can be used to predict the tracking error for a given reference.