Spectral analysis of heart rate variability: Acquisitionalysis software development

This work develops an acquisitionalysis software application to investigate the spectral content of the heart rate variability signal derived from an electrocardiographic (EKG) waveform. The location and strength of the frequency content reveals general information concerning sympathetic and parasympathetic activity within the autonomic nervous system of the study subject. Current investigations into pediatric head trauma patients have revealed specific correlations between spectral content of the heart rate variability and overall patient recovery. The levels of serum catecholamines, specifically epinephrine and norepinephrine, are also investigated for a possible correlation with both trauma severity and spectral power of the heart rate variability signal. Two frequency regions are of particular interest in the power spectral density waveform, the low frequency band (0.01-0.15 Hz) and the high frequency band (0.15-0.50 Hz). The low frequency band is indicative of sympathetic nervous system activity (such as body temperature and arterial blood pressure regulation) as well as some parasympathetic nervous system activity. The high frequency band is indicative of parasympathetic activity (such as respiratory sinus arrhythmia) only. In fact, a prominent peak located at approximately 0.20 Hz (of a normal human adult) represents heart rate variability at the respiratory frequency. Clinical application of the acquisition and analysis techniques described herein has shown that elevated levels of low-frequency HRV power are indicative of improved chances for recovery from severe brain injury. In contrast, brain-dead pediatric head trauma patients were found to possess near-zero low-frequency power. Acute animal studies have shown that decreases in low-frequency HRV power and systemic arterial blood pressure with little change in high-frequency HRV power, may be a characteristic indicator of endotoxin-induced septic shock. The acquisitionalysis package described in this work may, therefore, prove beneficial to critical care medicine, and advance our understanding of cardiovascular neurophysiology

Models of Regulation

A Review of The Politics of Regulation edited by James Q. Wilso

Manpower Training Programs in South Dakota : Socio-economic Attributes of Participants Associated with Training Outcomes

Because of the unemployment, underemployment, poverty and occupational opportunity problems experienced in South Dakota, it is appropriate that manpower programs currently operating in the State be studied. To maximize the potential benefits of these programs it is necessary to understand their structure, their purpose, their goals and their effects. Likewise, the extent of participation in the programs should be determined along with finding out what type of trainee is benefitting the least or the most from the training experience. There has been considerable research into a wide spectrum of manpower programs and manpower needs in urban areas; however, relatively little has been researched into the ways the same programs are operating and affecting the manpower problems in rural areas. Responding to this deficiency, the Rural Sociology Department of South Dakota state University began in Fall, 1971, a research project directed to producing greater understanding of the manpower programs currently operating in South Dakota. The general aims of the research project include the following: 1. A description of the manpower programs currently operating in South Dakota. 2. An assessment of the degree of success of the various manpower programs. 3. An examination of the association between possible differential participation rates and degrees of success to selected demographic, social, and economic characteristics of the participants. Before a comprehensive determination and evaluation of success, or lack of success, was attempted, and the relationships of demographic, social, and economic variables to program success were tested, some preliminary examinations were seen as advisable. Available sources of information on selected manpower programs needed to be identified, and available sources of data on the characteristics of the participants in the progre.ms gathered. An exploratory study was needed to examine the association between the socio-economic characteristics of participants in the programs to one criterion of success, namely, completion of the training programs. This study was done in conjunction with the research project mentioned above in an effort to fulfill some of the descriptive and exploratory needs of the project

Studies of the Mexican Deltocephalinae -1, 2 Aligia and Some New Allied Genera and Species (Homoptera: Cicadellidae)

Author Institution: Entomology Research Division, Agr. Res. Serv., U. S. Department of Agriculture, Washington, D. C., Professor Emeritus, Department of Zoology and Entomology, The Ohio State University, Columbus, OhioThe Mexican species of Aligia Ball and related genera are largely unknown or undescribed. Hepner (1942) published a study of the 32 species of Aligia known to occur in the United States, and some of these will undoubtedly be found in Mexico eventually. In this paper we describe three new species of Aligia; one new species of Frequenamia DeLong; and two new genera, one with two new species and the other with a single new species. All holotypes and allotypes are in the DeLong Collection; paratypes will be deposited in the collection of the United States National Museum

Mollusc shell periostracum as an alternative to tissue in isotopic studies

Recent studies have used carbon and nitrogen stable isotope ratios of preserved soft tissues to examine historical changes in trophic patterns of aquatic ecosystems. A limitation in this application is the difficulty in finding specimens for primary consumers, which can act as a surrogate for basal food sources in determining the trophic status of higher consumers. The availability of preserved soft tissues of invertebrate primary consumers is often limited in museum and archival collections; hard parts such as mollusc shells, however, are often abundant because of their ease of storage. We used stable isotope ratios of carbon and nitrogen to determine if there was a relationship between the isotopic composition of the periostracum of the shell and soft body tissue of freshwater molluscs. We found a significant correlation between (1) periostracum and tissue of freshly collected freshwater mussels, (2) ethanol-preserved adductor muscle tissue and dry-preserved mussels from museum collections, and (3) ethanol-preserved tissue and periostracum of gastropods from museum collections. The predictability of these relationships enhances the capacity to track changes in trophic complexity over time and responses of food webs to natural and anthropogenic environmental perturbations

A Study of Factors Associated With Outdoor Recreational Participation in South Dakota

Participation by South Dakotans in selected areas of outdoor recreation was studied to determine varying extents of participation and associated selected sociodemographic, socialization and attitudinal factors. A statewide random sample of 474 heads-of-households (or their spouses) was selected and interviewed using a pretested schedule. The findings were present in three forms: a descriptive summary, a nonparametric analysis of association and a multivariate analysis. The descriptive analysis revealed fishing, hunting and lakeside camping or picnicking to be the activities participated in most frequently. Conversely, water-skiing, ice fishing and snowmobiling were participated in least. Analysis of association showed that each of the sociodemographic and socialization variables employed in the study were significantly associated with participation in at least four of the selected outdoor recreational activities. Readership of conservation or outdoor sports magazines was significantly associated with all 11 activities studied. Age was associated with all activities except game bird hunting. Using a stepwise multiple regression analysis, 13 variables were found to contribute significantly to the total proportion of variance explained. They were sex, readership of outdoor sports magazines, age, children living at home, urban-rural residence, participation in predator control, attitudes towards game management, commitment to the dove hunting issue, race, marital status, income, education and enrollment in a course in safe handling of firearms. Males, regular readers of conservation or outdoor sports magazines, younger, householders with more children living at home, urbanites, participants in predator control, persons with less favorable sentiments regarding present game management regulations, highly committed advocates or opponents of a hunting issue, nonwhites, single persons or married persons dwelling together, persons with higher incomes, persons with less formal education and persons who had taken a course in safe handling of firearms participated more in outdoor recreational activities. Conclusions from the study were: 1. Although the findings indicate hunting, fishing and lakeside camping or picnicking to be popular outdoor leisure activities among South Dakotans, there is no consistent pattern regarding the attributes of individuals most likely to participate in these or other activities studied. 2. Participation in the various outdoor recreational activities selected for study depends on the characteristics of the activities. 3. Varying participation in outdoor recreational activities in South Dakota partially supports previously posited theories and perspectives. 4. The findings indicate sociodemographic, socialization and attitudinal variables are related to participation in the outdoor activities studied; thus, providing substantial support for the theoretical framework of this study. Over 52 percent of the variance in participation in outdoor recreation was explained in the regression analysis, and it is noted that the predominance of factors explaining variance in outdoor recreational behavior were sociodemographic