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PubMed2003

Terrorism and weapons of mass destruction: managing the behavioral reaction in primary care.

Any terrorist attack using weapons of mass destruction will result in substantial psychological trauma and stress. Primary care and emergency clinics will likely see patients who have stress-related emotional or physical symptoms, or exacerbations of preexisting health concerns. Significant psychological and behavioral reactions to an attack with weapons of mass destruction are certain, include both group and individual reactions, and will follow a predictable course. Possible group reactions include mass panic, acute outbreaks of medically unexplained symptoms, and chronic cases of medically unexplained physical symptoms. Possible individual reactions include psychiatric disorders such as posttraumatic stress disorder, which occurs in approximately 30% of people exposed to extreme trauma. Most people have symptoms of arousal that are normal reactions to abnormal events and that resolve with rest, reassurance, support, and education. Mandatory debriefings are not recommended, and medications may be used when more conservative measures are not sufficient.

Humans↗
PubMed1999

On the theory of behavioral mechanics.

The Theory of Behavioral Mechanics is the behavioral analogue of Newton's laws of motion, with the rate of responding in operant conditioning corresponding to physical velocity. In an earlier work, the basic relation between rate of responding and sessions under two FI schedules and over a range of commonly used session values had been shown to be a power function. Using that basic relation, functions for behavioral acceleration, mass, and momentum are derived here. Data from other laboratories also support the applicability of a power function to VI schedules. A particular numerical value is introduced here to be the standard reference value for the behavioral force under the VI-60-s schedule. This reference allows numerical values to be calculated for the behavioral mass and momentum of individual animals. A comparison of the numerical values of the momenta of two animals can be used to evaluate their relative resistances to change, e.g., to extinction, which is itself viewed as a continuously changing behavioral force being imposed on the animal. This overall numerical approach allows behavioral force-values to be assigned to various experimental conditions such as the evaluation of the behavioral force of a medication dosage.

Animals↗
PubMed1999

Role of leptin in women with eating disorders.

OBJECTIVE: This study investigated the role of leptin on eating behavior and reproductive function in eating disorders. METHOD: The subjects included 80 eating-disordered women, having different fat mass, eating behavior, and endocrine abnormalities, and 26 control women. Plasma leptin, insulin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), cortisol, insulin growth factor-1 (IGF-1), free T4 levels, percent body fat, eating behavior score, and menstrual status score were evaluated for each subject. RESULTS: In eating-disordered patients, log of leptin levels were significantly correlated with body fat mass, eating behavior score, menstrual status score, and insulin, LH, and FSH levels. Stepwise regression analysis showed that fat mass and eating behavior score were significant determinants of leptin levels. Furthermore, in patients undergoing recovery, leptin levels were determined by fat mass and/or eating behavior. DISCUSSION: These results suggest that leptin may play some role in counteracting the abnormal eating behavior, reproductive function, and fat mass in these disorders.

Adipose Tissue↗
PubMed1992

Socioeconomic and behavioral correlates of body mass index in black adults: the Pitt County Study.

BACKGROUND: Obesity is more prevalent among Black women than Black men, but there is little information on the correlates of obesity in Blacks. This study describes the relations of sociodemographic factors and health behaviors to body mass index in a southern, Black population. METHODS: In 1988, a community probability sample of 1784 Black adults, aged 25 to 50, was examined in Pitt County, NC. RESULTS: More women than men were at least 20% overweight (57% vs 36%). The relation of socioeconomic status (a composite of education and occupation) to age-adjusted body mass index level was inverse in women but not in men. Body mass index did not differ with either current energy intake or energy expenditure. Smokers and drinkers had lower age-adjusted levels than non-smokers and abstainers. CONCLUSIONS: Since the excess body mass index levels associated with low socioeconomic status in women could not be explained after controlling for adverse health behaviors, further epidemiologic study of risk factors for obesity in Black women is recommended.

Adult↗
PubMed1999

Leptin in women with eating disorders.

The aim of the present study was to determine the factors controlling leptin secretion and to clarify the role of leptin in eating disorders. The subjects were 152 eating-disordered women with different fat mass, eating behavior, and endocrine abnormalities and 24 age-matched control subjects. The body fat mass, eating behavior score, and plasma leptin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), triiodothyronine (T3), free thyroxine (T4), insulin, and cortisol levels were evaluated for each subject. In patients with eating disorder, logarithmic values for leptin were significantly correlated with the body fat mass (r = .828, P < .001), eating behavior score (r = .777, P < .001), and LH (r = .465, P < .001), FSH (r = .440, P < .001), T3 (r = .572, P < .001), insulin (r = .410, P < .001), and cortisol (r = -.389, P < .001) levels. After adjusting for fat mass, the partial correlations of log leptin with LH, FSH, insulin, and cortisol were not statistically significant, but log leptin remained correlated with T3 (r = .390, P < .01). Stepwise regression analysis showed that the body fat mass and eating behavior score were significant determinants of leptin levels. These results suggest that eating behavior, as well as the body fat mass, is the control factor for leptin secretion in eating disorders.

Adipose Tissue↗
PubMed1978

Mass spectrometry and gas chromatography of trimethylsilyl derivatives of catecholamine related molecules.

The trimethylsilyl derivatives of approximately 50 compounds related in structure to biogenic catecholamines have been studied in terms of their gas chromatographic and mass spectrometric behavior. The electron impact mass spectra of the trimethylsilyl derivatives of 3,4-dihydroxyphenylethylamine, 3,4-dihydroxyphenylacetic acid and 3,4-dihydroxyphenylethylamine and deuterated isotopic variants were compared to determine fragmentation characteristics of the amines, acids, alcohols and amino acids within this class of compounds. Analysis of shifts in the masses of major diagnostic ions in the spectra of structural analogs of these compounds has shown that structural modification of the structure can be identified and localized within these molecules. The gas chromatographic characteristics of these derivatives are reported, in terms of methylene unit values.

Catecholamines↗
PubMed2002

The dilemma of the selfish herd: the search for a realistic movement rule.

The selfish herd hypothesis predicts that aggregations form because individuals move toward one another to minimize their own predation risk. The "dilemma of the selfish herd" is that movement rules that are easy for individuals to follow, fail to produce true aggregations, while rules that produce aggregations require individual behavior so complex that one may doubt most animals can follow them. If natural selection at the individual level is responsible for herding behavior, a solution to the dilemma must exist. Using computer simulations, we examined four different movement rules. Relative predation risk was different for all four movement rules (p<0.05). We defined three criteria for measuring the quality of a movement rule. A good movement rule should (a) be statistically likely to benefit an individual that follows it, (b) be something we can imagine most animals are capable of following, and (c) result in a centrally compact flock. The local crowded horizon rule, which allowed individuals to take the positions of many flock-mates into account, but decreased the influence of flock-mates with distance, best satisfied these criteria. The local crowded horizon rule was very sensitive to the animal's perceptive ability. Therefore, the animal's ability to detect its neighbors is an important factor in the dynamics of group formation.

Animals↗
PubMed2002

Kang-Redner small-mass anomaly in cluster-cluster aggregation.

The large-time small-mass asymptotic behavior of the average mass distribution P(m,t) is studied in a d-dimensional system of diffusing aggregating particles for 1< or =d< or =2. By means of both a renormalization group computation as well as a direct resummation of leading terms in the small-reaction-rate expansion of the average mass distribution, it is shown that P(m,t) approximately (1/t(d))(m(1/d)/sqrt[t])(e(KR)) for m<<t(d/2), where e(KR)=epsilon+O(epsilon(2)) and epsilon=2-d. In two dimensions, it is shown that P(m,t) approximately ln(m)ln(t)/t(2) for m<<t/ln(t). Numerical simulations in two dimensions supporting the analytical results are also presented.

Journal Article↗
PubMed1983

The analysis of behavioral momentum.

Learned behavior varies in its resistance to change, depending on the rate of reinforcement. Resistance to change may be characterized as behavioral momentum, which in turn may be analyzed into terms corresponding to mass and velocity in classical physics. Behavioral mass may be inferred from changes in response rate when experimental conditions are altered. Relevant data were obtained by training pigeons to peck a key on two-component multiple variable-interval, variable-interval schedules. Six pigeons were studied on three pairs of variable-interval schedules in all possible orders. When performance stabilized, resistance to change was assessed by arranging response-independent food during periods between components and by extinction. For each operation, the data for all schedule performances converged onto a single function, permitting estimation of the ratio of behavioral masses for each pair of schedules. The response-independent food data suggested that the ratio of behavioral masses is a power function of the ratio of reinforcement rates and that behavioral mass may be measured on a ratio scale.

Journal Article↗
PubMedDate not supplied

Mathematical model for analysis of mass transfer for immobilized cells in lactic acid fermentation.

A new mathematical model is proposed to analyze the mass transfer behavior in lactic acid fermentation using immobilized cells entrapped in calcium alginate. The model is comprised of material balance equations for glucose, free lactic acid, and several ions. The dissociation rate of lactic acid (rdiss) is involved in the proposed equations. To solve the equations numerically, a modified calculating method is proposed. Through model analysis, the possible mass transfer behavior in the gel bead was discussed. The model is validated by comparisons with the experimental results obtained from batch and continuous fermentation. The simulations using the model were made to investigate the mass transfer limitation in the gel beads. The results showed that the cell density gradient was formed in the gel beads and it was caused by the accumulation of the inhibitory product (free lactic acid), not by substrate starvation. Moreover, unusual mass transfer behavior of lactate ion in the immobilization support was pointed out.

Biotechnology↗
PubMed1995

Radiographic appearance of the odontoid lateral mass interspace in the occipitoatlantoaxial complex.

STUDY DESIGN: This is an anatomic study in which the odontoid lateral mass interspace is evaluated radiographically in various positions of upper cervical spine rotation. OBJECTIVES: The objectives are to determine whether odontoid lateral mass interspace asymmetry exists in the ligamentously intact cervical spine and to define odontoid lateral mass interspace behavior during atlantoaxial rotation. SUMMARY OF BACKGROUND DATA: Controversy exists regarding the behavior of the odontoid lateral mass interspace during atlantoaxial rotation. The meaning of interspace asymmetry varies depending on the author and the method of study. Atlas fractures account for 7% of cervical spine fractures and are frequently associated with other cervical fractures, so an understanding of the radiographic anatomy is crucial to the evaluation of these patients. METHODS: Ten human cadaveric cervical spines were dissected of all but ligamentous soft tissue and were mounted and prepared for radiographic study in neutral position and in varying degrees of right and left rotation. Radiographs were evaluated for odontoid lateral mass interspace asymmetry in neutral and in rotated positions, and data were analyzed. RESULTS: Measurable asymmetry could be shown when comparing neutral positions and when comparing rotated with neutral positions. A statistically significant difference could not be proven in this asymmetry, although clinical significance is suggested by the analysis of the data. CONCLUSION: Measurable asymmetry can be present in the neutrally positioned, ligamentously intact atlanto-axial complex and is not necessarily indicative of instability. This agrees with the concept of the "neutral zone" as described by White and Panjabi in Clinical Biomechanics of the Spine. There is a trend for increasing odontoid lateral mass interspace on the side to which the head is rotated, and this odontoid lateral mass interspace is measurably different from the contralateral odontoid lateral mass interspace, indicating that odontoid lateral mass interspace asymmetry is not a good indicator for cervical instability in the otherwise asymptomatic individual.

Adult↗
PubMed2004

Spatial analysis of body mass index and smoking behavior among WISEWOMAN participants.

BACKGROUND: The WISEWOMAN program focuses on reducing cardiovascular disease (CVD) risk factors by providing screening and lifestyle interventions for many low-income and uninsured women. To provide the most effective interventions possible, it is important to understand the characteristics of WISEWOMAN participants and their communities. METHODS: We used baseline data collected for WISEWOMAN participants from five states (Connecticut, Michigan, Nebraska, North Carolina, and South Dakota) who had enrolled in WISEWOMAN between January 2001 and December 2002 in order to examine body mass index (BMI) and smoking behavior for evidence of spatial clustering. We then examined whether neighborhood characteristics in clusters of high-risk factors differed from neighborhood characteristics in other locations. RESULTS: Six percent of the WISEWOMAN participants lived in ZIP codes with high-BMI clusters, and 4% lived in ZIP codes with high-smoking clusters. High-BMI and high-smoking clusters occurred, however, in different locations from each other. The high-BMI-clustered ZIP codes were, on average, located in more disadvantaged areas. Most of the differences between the high-smoking-clustered ZIP codes and the remaining ZIP codes were not statistically significant. CONCLUSIONS: Our analysis revealed spatial clustering in CVD risk factors among WISE-WOMAN participants. We also found evidence of a correlation between high-BMI clusters and low socioeconomic status of the surrounding community. A more in-depth analysis of the relationship between risk factors (e.g., BMI) and community characteristics in clustered locations will provide further information concerning the role of the community in affecting individual behavior and should allow for tailoring interventions to reduce these risk factors more effectively.

Adult↗
PubMed1989

A behavioral quantal theory of brain function: an alternative to Lashley's continuity theory of mass action.

A behavioral quantal theory of brain function is formulated on the basis of a newly discovered step-wise relationship invariably present among the findings of three experiments by Tsai, et al. on the effects of (1) cerebral decortication, (2) cranial x-radiation, as well as (3) insulin, metrazol, and electroconvulsive shocks upon white rats' adaptive behavior during their learning of successive habit reversals and one-trial reversal problems. Confirmatory results from earlier investigators who studied effects of various current strengths of ECS upon learning and retention of various maze habits are also cited in support of the behavioral quantal theory of brain function which is proposed here as a close-up, more refined alternative to Lashley's continuity theory of mass action.

Animals↗
PubMed1997

Mass Spawning by Green Algae on Coral Reefs

Predawn episodes of mass spawning by green algae (up to nine species in five genera on a single morning) intermittently cloud Caribbean waters. Species- and sex-specific bouts of anisogamous gamete release occurred synchronously and predictably on a given morning, with closely related species spawning at different times. Algal sexual reproduction was seasonal, but, unlike the mass-spawning behavior of other sessile marine organisms, showed no lunar or tidal cycling. The discovery of mass-spawning behavior by these algae has important implications for future studies of the reproductive ecology and speciation of a vital, yet poorly understood, component of the coral reef community.

Journal Article↗
PubMed2006

Source-zone characterization of a chlorinated-solvent contaminated Superfund site in Tucson, AZ.

An extensive site-characterization project was conducted at a large chlorinated-solvent contaminated Superfund site in Tucson, AZ. The project consisted of several components, including traditional site-characterization activities, tracer tests, laboratory experiments conducted with core material collected from the site, and mathematical modeling. The primary focus of the work presented herein is the analysis of induced-gradient contaminant elution tests conducted in a source zone at the site, investigation of the potential occurrence of immiscible liquid in the saturated zone, characterization of the relationship between mass flux reduction and mass removal, and evaluation of the impact of source-zone management on site remediation. The results of the present study, along with those of prior work, indicate that immiscible liquid is likely present in the saturated zone at the site source zones. Extensive tailing and rebound was observed for the contaminant-elution tests, indicating nonideal transport and mass-transfer behavior. The elution data were analyzed with a source-zone-scale mathematical model, and the results indicated that nonideal immiscible-liquid dissolution was the primary cause of the observed behavior. The time-continuous relationship between mass flux reduction and mass removal associated with the plume-scale pump-and-treat operation exhibited an initial large drop in mass flux with minimal mass removed, followed by a period of minimal mass flux reduction and a second period of large reduction. This behavior reflects the impact of both source-zone and aqueous-plume mass removal dynamics. Ultimately, a greater than 90% reduction in mass flux was achieved for a mass removal of approximately 50%. The influence of source-zone management on site remediation was evaluated by conducting two predictive simulations, one for which the source zones were controlled and one for which they were not. A plume-scale model was used to simulate the composite contaminant concentrations associated with groundwater extracted with the pump-and-treat system, which were compared to measured data. The information generated from this study was used to enhance the site conceptual model, help optimize operation of the pump-and-treat system, and evaluate the utility of source-zone remediation.

Arizona↗
PubMed2003

Effect of sodium dodecyl sulfate on the rate of hydrogen evolution at a cathode.

The effect of H(2) evolution on the mass-transfer coefficient of cathode reduction of potassium ferricyanide at a mercury cathode was studied with the aim of (i) comparing the mass transfer behavior at a Hg cathode with that at solid electrodes under gas-evolving conditions and (ii) testing the effect of anionic surface-active agent on the mass transfer behavior of an H(2)-evolving Hg cathode. It is found that the mass transfer coefficient at the Hg cathode was much higher than the value at a solid cathode. The mass transfer coefficient at H(2)-evolving Hg was found to decrease in the presence of sodium dodecyl sulfate (SDS) surfactant by an amount ranging from 58.8 to 76%, depending on the H(2) discharge rate and the SDS concentrations.

Journal Article↗
PubMed1982

Postnatal development of adipose tissue in normal children on strictly controlled calorie intake.

The relations between adipose tissue development at birth, later expansion of fat mass and the behavior of fat mass and fat cell growth from birth to 12 mo of age have been studied in normal children born to normal, obese or diabetic mothers and maintained on strictly controlled calorie intake. A simple method for fat cell size determination on microsamples of fat tissue, specifically designed for small children, is reported. In the first 3 mo of life, a marked increase of fatty tissue from 13.4 +/- 0.4 to 20.3 +/- 0.8 percent of total body mass was observed. Subsequently, a sharp decrease in the relative amount of fat mass occurs, probably related to an increased energy expenditure or to a slightly higher protein content in the diet. No sex related differences in body weight, body fat mass, sum of skinfold thickness or fat cell weight were found throughout the study. No significant differences in body fat mass, sum of skinfold thickness and body fat mass as percent of body weight was observed at birth and at 3 or 6 mo of age in children of obese or gestational diabetic mothers, in comparison with children of normal mothers, and no significant correlation was found between maternal adiposity (sum of skinfold thickness or pre-gravidic overweight) or glucose tolerance (blood glucose area after OGTT) and adipose tissue development in the first 6 mo of life. Thus, in children on strictly controlled intake, obesity or diabetes in the mother do not relate to the rate of fat accumulation. Moreover, no relations were found between adipose tissue development at birth and subsequent rate of fat enlargement in the first year of life. Thus, when the interference of a different calorie intake is excluded, adiposity at birth has no predictive value for possible fatness later in infancy.

Adipose Tissue↗