Tortuosity in movement paths is related to cognitive impairment. Wireless fractal estimation in assisted living facility residents.

BACKGROUND: Using traditional assessment procedures, prior research demonstrated that deficiencies in gait and balance occur in the later stages of dementia. OBJECTIVE: We tested the hypothesis that an automated system capable of detecting path tortuosity (irregular movement) in elders would show that greater tortuosity was associated with greater cognitive impairment, potentially allowing early detection of dementia over time as tortuosity levels slowly increased. METHODS: An ultra-wideband sensor network using wireless transponders measured daytime locomotion to an accuracy of 20 cm in 14 elderly residents in an assisted living facility (ALF) as they traversed a shared living area while performing daily activities such as going to a dining area, conversing and watching television. Transponder location was updated at 0.4 sec intervals while in motion and revealed large individual differences in activity patterns. RESULTS: Fractal dimension (Fractal D), a measure of movement path tortuosity (directed vs. irregular or apparently aimless locomotion) was significantly and negatively correlated with cognitive status as measured by the Mini Mental State Examination administered to each participant at the study's end. CONCLUSIONS: Previous studies of locomotion in laboratory settings that have demonstrated gait variability increases with poor cognitive status have necessarily controlled various components of gait. The present results demonstrate that directional changes and other locomotion components can be studied by monitoring free movements in normal living settings over time. Implications for assessment and management of dementia-related wandering are discussed.

Treatment of substance-abusing jail inmates. Examination of gender differences.

Females incarcerated for drug-related offenses represent one of the fastest growing populations within jails and prisons. The few studies of female offenders with substance abuse disorders depict a population with multiple psychosocial problems and treatment needs, and one that is characterized by frequent exposure to sexual abuse and other violence. The current study examined intake assessment results from a sample of 1,655 substance-involved jail inmates referred to a jail treatment program in Tampa, Florida, including 26% female and 74% male inmates. The study was designed to identify gender differences in psychosocial characteristics and substance abuse treatment needs among jail inmates. Results indicate that female inmates more frequently experienced employment problems, had lower incomes, more frequently reported cocaine as the primary drug of choice, and were more likely to report depression, anxiety, suicidal behavior, and a history of physical and sexual abuse. Implications for developing specialized treatment approaches for female offenders are discussed, including use of integrated treatment strategies.

Extinction instead of incubation following classical aversive conditioning in dogs.

Two dogs received a single paired classical conditioning trial, with tone CS and 12 mA shock US. Both dogs then showed a conditioned blood pressure increase in response to the nonreinforced CS, which extinguished with additional nonreinforced presentations. The CR showed spontaneous recovery four days later, but reextinguished with additional nonreinforced presentations. The results were interpreted as not supporting Eysenck's theory of "incubation" following one-trial aversive conditioning.

Drug abuse history and treatment needs of jail inmates.

The current study evaluates the extent of prior drug use and psychosocial dysfunction related to drug use among 499 jail inmates referred to the Hillsborough County Sheriff's Office Substance Abuse Treatment Program. Results indicate that inmates were involved with drugs for an average of more than 7 years, and with cocaine for almost 5 years. The majority of inmates reported extremely heavy use of drugs in the month prior to the last arrest, including 83% that had used cocaine. Many drug-dependent inmates reported a shift over time from intranasal to freebase cocaine use. Half of all referrals indicated a pattern of regular use within a year of involvement with drugs. The need for lengthy, heavily structured, and intensive treatment approaches for drug-dependent jail inmates is underscored by a history of chronic cocaine and polydrug abuse, a compulsive pattern of drug use, few successful periods of voluntary abstinence, and severe disruption in vocational, social, and psychological functioning. Their history of infrequent and unsuccessful involvement in rehabilitation programs reflects a significant need for compulsory treatment following release from jail, community supervision to ensure compliance with treatment, and development of linkages between jail drug treatment programs, courts, and community treatment providers.

Potassium infusion attenuates avoidance-saline hypertension in dogs.

Previous studies have shown that a combination of avoidance conditioning schedules and increased intake of salt and water results in progressive hypertension in dogs within 14 days. The present experiments investigated the effects of increasing potassium intake upon blood pressure and heart rate of dogs made hypertensive by avoidance conditioning and salt-water loading. Two daily 30-minute sessions of free-operant avoidance conditioning were presented for 36 days during which isotonic saline was continuously infused into the arterial circulation (1.2 liters/day; 185 mEq Na+). Daily mean levels of systolic (22 +/- 5 mm Hg) and diastolic (12 +/- 4 mm Hg) pressure increased progressively in each dog during Days 1-14. Infusion of potassium chloride (100 mEq/day) from Days 15-28 resulted in progressive decreases in daily mean levels of systolic (-11 +/- 2 mm Hg) and diastolic (-8 +/- 1 mm Hg) pressure in each dog over this period. From Day 29-36, systolic (8 +/- 1 mm Hg) and diastolic (5 +/- 1 mm Hg) pressure increased. Normotensive dogs not on the avoidance schedule showed no change in arterial pressure in response to 14 days of potassium chloride infusion. These experiments show that the level of potassium, as well as sodium, intake significantly determines blood pressure levels in this form of experimental hypertension.

Progressive hypertension in dogs by avoidance conditioning and saline infusion.

A group of dogs was trained on a free-operant avoidance-conditioning task that evoked acute increases in arterial pressure and heart rate during each of three daily 30-minute sessions. After 15 days of exposure to this procedure under conditions of normal sodium intake, 24-hour mean levels of arterial pressure remained unchanged. Another group of dogs received continuous intrarterial infusion of isotonic saline at a constant rate of 185 mEq/24 hrs for 15 days, but no avoidance sessions. Again, 24-hour mean levels of arterial pressure did not change significantly. However, 24-hour mean levels of systolic (19.5 +/- 6.2 mm Hg) and diastolic (13.7 +/- 2.9 mm Hg) pressure rose progressively over a 15-day period in a third group of dogs exposed concurrently to the avoidance schedule and saline infusion procedure. The progressive hypertension was accompanied by no consistent changes in heart rate. These experiments indicate that behavioral stress can potentiate sodium hypertension and provide a new method for the study of physiological and behavioral factors in long-term blood pressure control.