Arthropod touch reception: spider hair sensilla as rapid touch detectors.

Wandering spiders like Cupiennius salei are densely covered by tactile hairs. In darkness Cupiennius uses its front legs as tactile feelers. We selected easily identifiable hairs on the tarsus and metatarsus which are stimulated during this behavior to study tactile hair properties. Both the mechanical and electrophysiological hair properties are largely independent of the direction of hair displacement. Restoring torques measure 10(-9) to 10(-8) Nm. The torsional restoring constant S changes non-linearly with deflection angle. It is of the order of 10(-8) Nm/rad, which is about 10,000 times larger than for trichobothria. Angular thresholds for the generation of action potentials are ca.1 degrees. Electrophysiology reveals a slow and a fast sensory cell, differing in adaptation time. Both cells are movement detectors mainly responding to the dynamic phase (velocity) of a stimulus. When applying behaviorally relevant stimulus velocities (up to 11 cm s(-1)) threshold deflection for the elicitation of action potentials and maximum response frequency are reached as early as 1.2 ms after stimulus onset and followed by a rapid decline of impulse frequency. Obviously these hairs inform the spider on the mere presence of a stimulus but not on details of its time-course and spatial orientation.

Arthropod touch reception: stimulus transformation and finite element model of spider tactile hairs.

Striving towards an in depth understanding of stimulus transformation in arthropod tactile hairs, we studied the mechanical events associated with tactile stimulation. A finite element model was developed taking a tarsal tactile hair of the spider Cupiennius salei as an example. Considering hair diameter, wall thickness, and curvature, the hair is subdivided into six regions each with its specific mechanical properties. When the hair is touched from above with a flat surface oriented parallel to the tarsus the point of stimulus contact moves towards the hair base with increasing load and hair deflection. Thereby the effective lever arm is reduced protecting the hair against breaking near its base. At the same time the mechanical working range of the hair increases implying higher mechanical sensitivity for small deflections (about 5x10(-5) N/degrees) than for large deflections (about 1x10(-4) N/degrees). The major stresses within the hair shaft are axial stresses due to bending. The position of stress maxima moves along the shaft with the movement of the stimulus contact point. Remarkably, the amplitude of this maximum (about 1x10(5) N/m2) hardly changes with increasing loading force due to the way the hair shaft is deflected by the stimulus.

Resource utilization control processes as indicators of quality in managed care organizations: a proposal.

Central to the development of a competitive market for managed care products is the ability to measure the quality of care provided by individual managed care organizations (MCOs). Several types of quality measures could be considered for this purpose: patient and provider satisfaction, a listing of specific services provided to patients, or clinical outcomes of such services. Although assessing quality with measures of the process of care is commonplace, we propose developing measures of the production processes that control utilization of health care resources within an organization. Evaluation of these production or resource utilization control processes, although not a substitute for health outcomes assessment, may improve our knowledge of the delivery of services within managed care organizations. We present a paradigm for evaluation of health care resource utilization control processes within managed care organizations based on our description of internal and external controls for health care resource management. This paradigm can serve as a framework for further research into the quality of care provided by these organizations and the processes of health care resource management in MCOs.

Clinical characteristics of women with a history of childhood abuse: unhealed wounds.

OBJECTIVES: To determine the prevalence of childhood physical or sexual abuse in women seen in primary care practices; to identify physical and psychologic problems associated with that abuse; and to compare the effects of childhood physical vs sexual abuse and childhood vs adult abuse. DESIGN: Cross-sectional, self-administered, anonymous survey. SETTING: Four community-based, primary care internal medicine practices. PATIENTS: A total of 1931 women of varied age and marital, educational, and economic status examined from February through July 1993. MAIN OUTCOME MEASURES: Prevalence of physical and sexual abuse, physical symptoms, psychological symptoms (Symptom Checklist-22), alcohol abuse (CAGE questions), and street drug use. RESULTS: Of the 1931 respondents, 424 (22.0%) reported childhood or adolescent physical or sexual abuse. Compared with women who reported never having experienced abuse (n=1257), women who reported abuse as children but not adults (n=204) had more physical symptoms (mean+/-SE, 6.2+/-0.2 vs 4.0+/-0.9; P<.001) and had higher scores for depression, anxiety, somatization, and interpersonal sensitivity (low self-esteem) (P<.001); were more likely to be abusing drugs (prevalence ratio [PR], 4.7; 95% confidence interval [CI], 2.9-7.6) or to have a history of alcohol abuse (PR, 2.2; 95% CI, 1.5-3.2); were more likely to have attempted suicide (PR, 3.7; 95% CI, 2.6-5.1); and were more likely to have had a psychiatric admission (PR, 3.2; 95% CI, 2.2-4.7). Women abused only as children did not differ from women who reported current, but not childhood, abuse in number of physical symptoms, emotional distress, substance abuse, or suicide attempts. Patients who reported both childhood and adult abuse had higher levels of psychological problems and physical symptoms than those who reported childhood or adult abuse alone. CONCLUSIONS: Childhood physical or sexual abuse is associated with adult health problems including physical symptoms, psychological problems, and substance abuse; for many variables, this association is as strong as for patients experiencing current abuse.

Health systems evaluation of telemedicine: a staged approach.

Telemedicine promises greater access to health care of higher quality, potentially at lower cost. The diverse applications of telemedicine technology developed to date have not been evaluated systematically in terms of their ability to achieve these goals. Furthermore, the great variety in telemedicine applications and the far-reaching consequences of new information systems for health care delivery pose challenges to traditional methods of technology assessment. Methods appropriate for mature technologies may not be suitable for emerging ones and, indeed, may risk stifling their development with premature negative conclusions. The staged approach to technology assessment proposed here matches the analysis to the technology's stage of development. It focuses on access, quality, and cost and considers the communication pathway employed in the telemedicine application. A staged approach to technology assessment can inform and foster the development of new telemedicine technology while allowing health care delivery systems to make rational decisions about adopting telemedicine.

The "battering syndrome": prevalence and clinical characteristics of domestic violence in primary care internal medicine practices.

OBJECTIVES: To determine the prevalence of domestic violence among female patients and to identify clinical characteristics that are associated with current domestic violence. DESIGN: Cross-sectional, self-administered, anonymous survey. SETTING: 4 community-based, primary care internal medicine practices. PATIENTS: 1952 female patients of varied age and marital, educational, and economic status who were seen from February to July 1993. MEASUREMENTS: The survey instrument included previously validated questions on physical and sexual abuse, alcohol abuse, and emotional status and questions on demographic characteristics, physical symptoms, use of street drugs and prescribed medications, and medical and psychiatric history. RESULTS: 108 of the 1952 respondents (5.5%) had experienced domestic violence in the year before presentation. Four hundred eighteen (21.4%) had experienced domestic violence sometime in their adult lives, 429 (22.0%) before age 18 years, and 639 (32.7%) as either an adult or child. Compared with women who had not recently experienced domestic violence, currently abused patients were more likely to be younger than 35 years of age (prevalence ratio [PR], 4.1 [95% CI, 2.8 to 6.0]); were more likely to be single, separated, or divorced (PR, 2.5 [CI, 1.7 to 3.6]); were more likely to be receiving medical assistance or to have no insurance (PR, 4.3 [CI, 2.8 to 6.6]); had more physical symptoms (mean, 7.3 +/- 0.38 compared with 4.6 +/- 0.08; P < 0.001); had higher scores on instruments for depression, anxiety, somatization, and interpersonal sensitivity (low self-esteem) (P < 0.001); were more likely to have a partner abusing drugs or alcohol (PR, 6.3 [CI, 4.4 to 9.2]); were more likely to be abusing drugs (PR, 4.4 [CI, 1.9 to 10.4]) or alcohol (PR, 3.1 [CI, 1.5 to 6.5]); and were more likely to have attempted suicide (PR, 4.3 [CI, 2.8 to 6.5]). They visited the emergency department more frequently (PR, 1.7 [CI, 1.2 to 2.5]) but did not have more hospitalizations for psychiatric disorders. In a logistic regression model into which 9 risk factors were entered, the likelihood of current abuse increased with the number of risk factors, from 1.2% when 0 to 1 risk factors were present to 70.4% when 6 to 7 risk factors were present. CONCLUSIONS: In a large, diverse, community-based population of primary care patients, 1 of every 20 women had experienced domestic violence in the previous year; 1 of every 5 had experienced violence in their adult life; and 1 of every 3 had experienced violence as either a child or an adult. Current domestic violence is associated with single or separated status, socioeconomic status, substance abuse, specific psychological symptoms, specific physical symptoms, and the total number of physical symptoms.

PIP: This cross-sectional study determined the prevalence of domestic violence among female patients presenting to four community-based primary care internal medicine practices in Baltimore, Maryland, between February and July, 1993. Furthermore, it identified clinical characteristics associated with domestic violence. A total of 1952 female patients of diverse socioeconomic backgrounds participated in a self-administered, anonymous survey that solicited data on physical and sexual abuse, alcohol abuse, emotional status, demographic characteristics, physical symptoms, use of street drugs and prescribed medications, and medical and psychiatric history. Of the 1952 respondents, 108 (5.5%) had experienced domestic violence in the previous year, 418 (21.4%) had experienced violence sometime in their adult lives, 429 (22%) before age 18 years, and 639 (32.7%) as either an adult or a child. Current violence status is associated with single or separated status, substance abuse, specific psychological symptoms, specific physical symptoms, and the total number of physical symptoms. In a logistic regression model, the likelihood of current abuse increased with the number of risk factors. The magnitude of these associations supports the idea that domestic violence is a significant medical public health problem. Detection of domestic violence by physicians or other health care professionals might alter both the diagnostic and treatment plans for these women.

Styles of care provided to children in the United States: a comparison by physician specialty.

This study was based on findings from a national survey of physicians that was conducted from 1975 to 1977. The data concern face-to-face encounters with children in the ambulatory care setting. Over one half of the practices of pediatricians consisted of infants and preschoolers, whereas well over 50 percent of the child patients of other types of physicians were 10 to 19 years old. The proportion of visits dealing with a problem already under care was consistently greater for specialists other than primary care physicians; the proportion of visits for preventive care was much lower in the practices of these specialists than in primary care practice. These findings suggest that other specialists are functioning in ways different from primary care physicians. As compared with family physicians, pediatricians performed more diagnostic tests for all diagnoses and more immunizations and counseling about growth and development, were more likely to have seen children previously for problems other than the one dealt with in the visit under consideration, and were more likely to report that no specific therapy was required (except for well-child care). However, family physicians did more counseling about family and sex matters than pediatricians, were much more likely to have seen musculoskeletal and skin problems among 10- to 19-year-old patients, and were much more likely to have administered cauterization, cryotherapy, or suturing for skin problems. Family physicians provided more counseling of all types and did more minor surgical procedures than general practitioners. These and other findings show the existence of systematic differences across specialties in the care of children, even for apparently similar problems.

A profile of pediatric practice in the United States.

We profiled pediatric practice in the United States through a second-order analysis of data gathered in 1977 from 429 practicing pediatricians. Age, sex, board certification status, practice arrangement, and practice location of pediatricians in the United States were evaluated, as well as their patterns of practice. The number of and reasons for visits made to pediatricians by patient age and sex were tabulated. Child health supervision and diseases of the upper and lower parts of the respiratory tract accounted for 84.5% of the principal diagnoses made in 21,784 visits to the sample of pediatricians studied. These data may be useful in planning pediatric primary care residency training program curricula and in making planning decisions regarding the number and distribution of pediatricians nationally.