Days Of Recovery Period Research Articles

A Two-Phase Anaerobic Digestion Process (UASB-UASB): Induced Failure and System Recovery Using a Step Loading Reduction Approach and Modified Recycle Ratio (RR)

This research demonstrated the feasibility of recovery of a UASB-UASB system treating simulated sewage sludge, after operating in a deliberate failure mode. The approach employed an application of step-loading reduction and a modification of the internal recycle ratio (RR). The system recovered exponentially (r2 = 0.99) and logarithmically (r2 = 0.81), with an increase in HRT (loading reduction), in so far as COD (sol) removal efficiency (92%) and CH4 gas production (100%), were concerned. The system appeared to return to its initial stage of operation, after 43 days of recovery period, by the application of a two-step increase in the HRTM-UASB at 1.5 and 5.5 times that of the failure HRTM-UASB (0.63 days); coincidentally, a dimensional time of 5.5 and 10 times the minimum HRT was employed for the overall system and the M-UASB, respectively.

Lateral parabrachial nucleus and angiotensin II-induced hypertension.

The objective of this study was to determine if ablation of the lateral parabrachial nucleus (LPBN) would prevent angiotensin II-induced hypertension in rats. Thirteen male Sprague-Dawley rats were studied. Bilateral electrolytic lesions in the LPBN were produced in six rats; the remaining seven rats were subjected to sham lesion surgery only. All rats were instrumented with vascular catheters and housed in metabolism cages. Daily measurements during the 16-day protocol included arterial pressure, heart rate, water intake, urine output, and urinary sodium excretion. Periodically throughout the protocol depressor responses to ganglion blockade and to blockade of V1-type vasopressin receptors also were measured. The protocol was divided into three control-period days, 10 days of continuous (24 hr/day) angiotensin II infusion (10 ng/min i.v.), and three recovery-period days. There were no significant differences between the two groups of rats for any variable during the control period. During angiotensin II infusion, sham-lesion rats exhibited a progressive increase in arterial pressure and the depressor response to ganglion blockade and a decrease in urinary sodium excretion. No other variable was significantly changed. In rats with LPBN lesions, arterial pressure was significantly increased only on days 1 and 3 of angiotensin II infusion. No other variable was affected. It was concluded that ablation of the LPBN in rats prevented sustained hypertension during intravenous infusion of angiotensin II by interfering with neurogenic pressor mechanisms normally activated by the peptide.

Biological aspects of suicide: circadian disorganization.

Disturbances in the circadian rhythmicity of biological functions have been reported in various mental disorders. Four lines of research--hormonal, electroencephalographic, cerebral spinal fluid, and circadian rhythmicity--suggest possible changes in suicidal individuals. During a study investigating the effect of a photoperiod shift on circadian rhythms, 15 male, healthy, normal subjects were used. Following a 5-day baseline period a 12-hour photoperiod shift took place and was followed by 10 days of recovery period. Multiple parameters were monitored. Two weeks following completion of the study one subject suicided. The data were examined to determine whether the suicided subject differed, rhythmically, from other subjects. Summation dials describing phase changes and vector difference dials describing dynamic phase relationships of rhythm pairs showed that the rhythms of this subject were poorly synchronized internally during baseline. Total urinary output of all parameters was lower than all other subjects during baseline and more of his urinary parameters rephased incompletely during recovery. The results suggest that circadian asynchrony and an inability to respond effectively to a phase shift may characterize a presuicidal state. These results are discussed in terms of the four lines of research involving biological aspects of suicide and suggest some intriguing interactions.