16 resultados para Myopic and farsighted behavior
em DigitalCommons@The Texas Medical Center
Resumo:
Background. Sexual orientation and sexual behavior among men have shown disagreement in past studies. The term "on the down low" has been adopted by many to describe "straight" identifying men who have sex with men but do not inform their primary female partner. Methods. This secondary analysis of data collected from the "DASH Project---A Hepatitis B Vaccine Model for HIV Vaccine Trial in Drug Users," assessed sexual behavior patterns among African American drug-using men over time. Using a screener questionnaire to determine sexual orientation and sexual behavior of the men, the study specifically evaluated "straight" identified men who have sex with women only (MSW) to determine what factors were associated with sexual behavior variation to include men during follow-up. The Fisher's Exact Test was used to evaluate the factors. Results. Variation of sexual behavior was highest among "bisexual" identified men followed by "gay" identified men. Fifteen of the original 593 "straight" and MSW men had sexual behavior variation to include men. In the analysis of "straight" and MSW men with variation in sexual behavior compared to those who did not, living on the streets, greater number of sexual partners, trading sex for drugs, and trading sex for money were associated with sexual behavior variation (all p-values <0.01). Conclusions. The factors were only associated when considering the interview when the variation occurred. The same factors at screening were not predictive of sexual behavior variation in the future. Environmental factors, such as living situation, appear to play a role in sexual behavior variations in "straight" and MSW men. ^ Keywords. sexual behavior, sexual orientation, Fisher's Exact Test^
Resumo:
The purpose of this study is to examine associations between adolescents’ Internet use, exposure to pornography online, and sexual behavior. This cross-sectional study examines data collected from an HIV, sexually transmitted infection, and pregnancy prevention program being evaluated in inner-city middle schools. Chi-squares were used to examine differences in Internet use and exposure to Internet pornography by gender, race/ethnicity, and sexual behavior. Univariate and multivariate logistic regression were used to examine associations between Internet use, exposure to Internet pornography, and sexual behavior. Ninety-four percent of students have used the Internet. Sixty-two percent of students had accidentally seen pornography on the Internet and 35% had purposefully viewed pornography online. Students who experienced sexual solicitation and who purposefully viewed pornography online were more likely to report lifetime and current sexual behavior. Additional research is needed to understand the impact of Internet use and exposure to Internet pornography on adolescents’ sexual behavior.^
Resumo:
For adolescents, unprotected sexual intercourse is the primary cause of sexually transmitted disease (STD), including Human Immunodeficiency Virus (HIV) infection (virus which causes Acquired Immunodeficiency Syndrome (AIDS)), and pregnancy. Although many studies on adolescent sexual behavior have addressed racial/ethnic differences, few studies have examined the relation between race/ethnicity while controlling for other sociocultural and psychosocial variables. The purpose of this study is to examine the relationship between racial/ethnic categories and selected sociocultural and psychosocial variables, with reported adolescent sexual risk-taking and preventive behavior.^ A self-administered questionnaire was used to collect information from 3132 students in a Texas school district (Section 3.5.2). The instrument contained approximately 100 questions on demographic characteristics, sexual behavior, and psychosocial determinants of sexual behavior. Based on the findings of this study, the following major conclusions are made: (1) There are differences in reported sexual risk-taking and preventive behavior among Black, Hispanic and White adolescents in this study. The stratified analysis by gender further suggests significant gender differences in reported sexual behavior among the three racial/ethnic groups. (2) Gender, living arrangement, academic grades, and language spoken at home modified the association between reported sexual risk-taking and preventive behavior and race/ethnicity in this study. This suggests that these sociocultural variables should be considered in future research and practice involving multicultural populations. (3) There are differences in selected psychosocial determinants among the three racial/ethnic groups and between males and females. These differences were consistent with the reported sexual risk-taking and preventive behaviors among race/ethnicity and gender for adolescents in this study. The findings support the consideration of psychosocial determinants in research and interventions addressing adolescent sexual behavior among different racial/ethnic groups.^ Based on the results of this study, two recommendations for practice are made. First, health professionals developing interventions for adolescents from different cultural backgrounds and gender need to be familiar with the specific sociocultural and psychosocial factors which will reduce risky sexual behavior, and promote protective behavior. Second, the need for immediate, realistic, and continuous HIV/STD and pregnancy prevention programs for children and adolescents should be considered. ^
Resumo:
An emerging body of research suggests that the social capital available in one's social environment, as defined by supportive and caring interpersonal relationships, may provide a protective effect against a number of youth risk behaviors. In exploring the potential protective effect of social capital at school and at home on adolescent health and social risk behavior, a comprehensive youth risk behavior study was carried out in El Salvador during the summer of 1999 with a sample of 984 secondary school students attending 16 public rural and urban schools. The following dissertation, entitled Social Capital and Adolescent Health Risk Behavior in El Salvador, presents three papers centered on the topics of social capital and risk behavior. ^ Paper #1. Dangers in the Adolescent River of Life: A Descriptive Study of Youth Risk Behavior among Urban and Rural presents prevalence estimates of four principal youth risk behavior domains—aggression, depression, substance use, and sexual behaviors among students primarily between the ages of 13 and 17 who attend public schools in El Salvador. The prevalence and distribution of risk behaviors is examined by gender, geographic school location, age, and subjective economic status. ^ Paper #2. Social Capital and Adolescent Health Risk Behavior among Secondary School Students in El Salvador explores the relationship between social resources (social capital) within the school context and several youth risk behaviors. Results indicated that students who perceived higher social cohesion at school and higher parental social support were significantly less likely to report fighting, having been threatened or hurt with a weapon, suicidal ideation, and sexual intercourse than students with lower perceived social cohesion at school and parental social support after adjusting for several socio-demographic variables. ^ Lastly, paper #3. School Health Environment and Social Capital : Moving beyond the individual to the broader social developmental context provides a theoretical and empirical basis for moving beyond the predominant individual-focus and physical health concerns of school health promotion to the larger social context of schools and social health of students. This paper explores the concept of social capital and relevant adolescent development theories in relation to the influence of social context on adolescent health and behavior. ^
Resumo:
Tumors comprising the spectrum of hemangiopericytoma/ malignant solitary fibrous tumor (HPC/SFT) are thought to arise from fibroblasts and represent a small subset of soft tissue sarcomas. Surgery is typically the treatment of choice for localized disease, with reported 10-year overall survival rates of 54-89% after complete surgical resection. However, for the approximately 20% of HPC/SFT patients who eventually develop local recurrences and/or distant metastases, options for effective treatment are limited and are poorly defined. Alternative therapeutic options are therefore needed for improved palliation and disease control. We hypothesize that HPC/SFT are a spectrum of soft tissue tumors with unique clinical, pathological, and molecular makeup and clinical behavior. HPC/SFT respond to unique therapeutic agents that specifically target aberrations specific to these tumors. We retrospectively reviewed the characteristics and the clinical outcomes for all HPC/SFT patients whose tumor specimens have been reviewed at the MD Anderson Cancer Center from January 1993 to June 2007 by a MD Anderson pathologist and were treated at the institution with available electronic medical records. We identified 128 patients, 79 with primary localized disease and 49 with recurrent and/or metastatic disease. For the 23 patients with advanced HPC/SFT who received adriamycin-based, gemcitabine based, or paclitaxel chemotherapy as first- or second-line therapy, the overall RECIST response rate was 0%. Most patients achieved a brief duration of disease stabilization on chemotherapy, with median progression-free survival (PFS) period of 4.6 months. For the 14 patients with advanced HPC/SFT who received temozolomide and bevacizumab systemic therapy, the overall RECIST response rate was 14%, with the overall Choi response rate of 79%. The median PFS for the cohort was 9.7 months with a median 6-month progression free rate of 78.6%. The most frequently observed toxic effect of temzolomide-bevacizumab therapy was myelosuppression. We have designed a phase II study to evaluate the safety and efficacy of temozolomide-bevaciumab in locally advanced, recurrent, and metastatic HPC/SFT in a prospective manner. Combination therapy with temozolomide and bevacizumab may be a potentially clinically beneficial regimen for advanced HPC/SFT patients.
Resumo:
The current study evaluates the effectiveness of an intensive home-based treatment program, Families First, on the behaviors of children and adolescents suffering from mental disorders and being at risk for out-ofi home placement. The sample included 85 youngsters and their families from a semi-rural community. The Diagnostic Interview for Children and Adolescents-Revised (DICA-R) was administered to the children, and the Child Behavior Checklist (CBCL) was completed by a parent at pretreatment and posttreatment. The families participated in a 4-6 week, intensive home intervention where crisis intervention, social support services, and needed psychological services were offered. The results indicated that both externalizing and internalizing behavior problems in youngsters with different diagnoses of mental disorders were significantly reduced at posttreatment as indicated by their CBCL scores. Furthermore, youngsters with a diagnosis of Oppositional Defiant Disorder seemed to benefit the most, as evidenced by the improved scores on most subscales of the CBCL. Youngsters with mood disorders and conduct disorders seemed to benefit in their most deficient areas, internalizing behavior problems and delinquent behaviors, respectively. Finally, after participating in Families First, more than half of the youngsters in the sample were able to stay home with their families
Resumo:
Cultural models of the domains healing and health are important in how people understand health and their behavior regarding it. The biomedicine model has been predominant in Western society. Recent popularity of holistic health and alternative healing modalities contrasts with the biomedical model and the assumptions upon which that model has been practiced. The holistic health movement characterizes an effort by health care providers and others such as nurses to expand the biomedical model and has often incorporated alternative modalities. This research described and compared the cultural models of healing of professional nurses and alternative healers. A group of nursing faculty who promote a holistic model were compared to a group of healers using healing touch. Ethnographic methods of participant observation, free listing and pile sort were used. Theoretical sampling in the free listings reached saturation at 18 in the group of nurses and 21 in the group of healers. Categories consistent for both groups emerged from the data. These were: physical, mental, attitude, relationships, spiritual, self management, and health seeking including biomedical and alternative resources. The healers had little differentiation between the concepts health and healing. The nurses, however, had more elements in self management for health and in health seeking for healing. This reflects the nurse's role in facilitating the shift in locus of responsibility between health and healing. The healers provided more specific information regarding alternative resources. The healer's conceptualization of health was embedded in a spiritual belief system and contrasted dramatically with that of biomedicine. The healer's models also contrasted with holistic health in the areas of holism, locus of responsibility, and dealing with uncertainty. The similarity between the groups and their dissimilarity to biomedicine suggest a larger cultural shift in beliefs regarding health care. ^
Resumo:
One of the central goals of neuroscience research is to determine how networks of neurons control and modify behavior. One of the most influential model systems for this kind of analysis is the siphon and gill withdrawal reflex of the marine mollusc A. californica. In response to tactile stimulation, the siphon displays 3 different responses: (1) a posterior pointing and leveling (flaring) of the siphon in response to tail stimulation (the siphon T response), (2) constriction and anterior pointing to head stimulation (the siphon H response) and (3) constriction and withdrawal between the animal's parapodia (the siphon S response). The siphon S response is pseudoconditioned by a noxious tail stimulus to resemble the siphon T response. Behavioral and combined behavioral/intracellular studies were conducted to determine the motor neuronal control of these behaviors and to search for mechanisms of siphon response transformation following pseudoconditioning. The present studies have found that the flaring component of pseudoconditioned siphon S responses occurs during mantle pumping (MP) triggered by noxious tail stimulation. Siphon stimulation also triggers MP, as recorded in neurons of the Interneuron II pattern generator which commands MP. The 4 LF$\rm\sb{SB}$ siphon motor neurons (SMNs) were found necessary and sufficient for the siphon T response, while SMNs RD$\rm\sb S$ and LD$\rm\sb{S1}$ were found necessary and sufficient for the siphon H response. Following pseudoconditioning, there is an increase in the number of evoked spikes to the test stimulus for the LF$\rm\sb{SB}$ cells and a decreased number for RD$\rm\sb S.$ Siphon flaring occurring during the pseudoconditioned response correlates with increased LF$\rm\sb{SB}$ activity during triggered MP cycles. This suggests that psuedoconditioning is in part due to reconfiguration of the motor outputs of the Interneuron II network. These results suggest that these defensive responses are controlled and patterned by a well-defined, finite set of motor neurons and interneurons (Interneuron II) that are dedicated to specific behavioral functions, but also have parallel distributed properties. ^
Resumo:
Serotonin (5-HT) neurotransmission deficits have been implicated in impulsive aggression. A Trp-free beverage of amino acids competitively inhibits Trp uptake into the brain for 5-HT synthesis and also lowers endogenous plasma Trp for several hours. This has worsened mood and/or increased aggressive behavior, especially in hostile persons or those with histories of depression. In 24 community-recruited men (12 each with and without significant aggression histories), aggressive and impulsive behavior in the laboratory was assessed before and after plasma Trp depletion and Trp loading. In the aggression model, subjects were provoked by periodic subtractions of participation earnings, and these subtractions were blamed on a ficitious other participant. Aggression was measured as the responses the subject made to subtract money from his antagonist. Impulsiveness was operationalized as: (1) the choice of smaller reward after a shorter delay over having to wait longer to receive a larger reward, and (2) “false alarm” commission errors in a modified Continuous Performance Task, which represent a failure to inhibit responding to stimuli similar (but not identical) to target stimuli. Finally, plasma cortisol and Trp were measured under each condition immediately following a aggression testing session when subjects were highly provoked. I hypothesized that 5-HT may tonically modulate (inhibit) the hypothalmnic-pituitary-adrenal stress response, such that Trp depletion may enhance the cortisol response to high provocation in aggressive men. ^ Trp depletion had no effect in the laboratory tasks purported to measure impulsive behavior, and failed to cause increases in aggressive behavior under low provocation conditions. Under higher provocation, however, aggressive responses we re elevated under Trp-depleted conditions relative to Trp-loaded conditions in aggressive men, whereas the reverse was true in nonaggressive men. Cortisol levels nonsignificantly paralled the group differences in aggression under Trp-depleted and Trp-loaded conditions. Aggressive men achieved lower plasma Trp levels after Trp loading than did nonaggressive men, possibly due to heavy alcohol use histories. The high post-loading plasma Trp levels in nonaggressive men tended also to correlate with their aggressive responding rates, due perhaps to increases in other psychoactive Trp metabolites. ^
Resumo:
The purpose of this study was to determine whether depression is a factor in explaining the difference in sex behaviors among adolescents with different ethnic backgrounds, family and school contexts. We hypothesize that adolescents with a higher number of depressive symptoms are more likely to engage in sexual risk behaviors than adolescents with fewer depressive symptoms. Further, adolescent depression and sexual behaviors are mediated or moderated by individual characteristics, family and school contexts. ^ Background. large ethnic disparities exist in adolescent engagement in risky sexual behaviors, yet, there is little in the literature that explains these disparities. Studies of sexual behavior of youths abound; yet, there is little literature on the prevalence and correlates of depression or the association between depression and sexual behaviors among different ethnic groups. Objectives. (1) To determine ethnic differences in the prevalence of depressive symptoms using data collected through the National Longitudinal Study of Adolescent Health (Add Health). (2) To determine predictors of sex risk behaviors among adolescents, including the role of depression. (3) To identify predictors of depression among these adolescents. Methods. Add Health data from wave 1 and wave 2 interviews of 7th–12th graders were analyzed using multivariate models constructed with both depression and sexual behavior as outcome variables. Logistic regression models determined whether and to what extent the independent variables, including depression, sex behaviors, demographic factors, individual and family characteristics, and school context were related to the probability of engaging in risky sexual behaviors. Results. Ethnic differences in depressive symptoms did not persist after demographic and contextual variables were included in the model. Sex behaviors all shared the hypothesized relationship with depressive symptoms. The odds of risky sex behaviors increased as number of depressive symptoms increased. Depression was predicted by marijuana use and having a serious argument with father for males at Wave 1 and by age and future orientation for females. Wave 2 depression was predicted by Wave 1 depression. ^
Resumo:
Objective. To explore (1) the association between "club drug" use and unprotected anal intercourse (UAI) and (2) the association between binge drug use and UAI among HIV seronegative men who have sex with men (MSM) seeking HIV/STD testing at a local clinic in Houston. ^ Study design. A sub-sample of 297 HIV seronegative MSM from a cross-sectional study of drug and sexual behavior in Houston was conducted in 2006. Patients who were seeking HIV/STD testing at a local MSM-identified STD clinic were recruited for an anonymous computer-assisted interview. Analysis of identified secondary data consisted of self-reported information about demographic characteristics, use of drugs, and sexual behaviors. ^ Results. With new and casual sex partners, there was a strong and statistically significant association between use of "club drugs" and UAI. No association between binge drug use and UAI was evident. Men aware of HIV seropositivity or unaware of the HIV serostatus of their primary partner were less likely to report UAI. ^ Conclusion. These data suggest that in the Houston area, HIV-negative MSM club drug users, particularly multiple drug users, are at higher risk of UAI than comparable MSMs who do not use club drugs. Episode-level data regarding binge use of these and other drugs, and UAI should be collected in future studies to explore their relationship. The 'new partner' category should be added to sex partner types to measure sex and drug use behaviors in future studies.^ Keywords. HIV-negative MSM; club drugs; unprotected anal intercourse; binge drug use. ^
Resumo:
This research is a secondary analysis of the Qué Sabrosa Vida population-based cross-sectional study of two predominately Mexican American communities located along the Texas-Mexico border in 2000. There were two aims for this research. The first was to determine the relationship between knowledge of exercise and water recommendations, and exercise behavior and water consumption. The second was to determine the relationship between exercise behavior and percentage of energy consumption from beverages. Chi-square analysis revealed the majority of both populations had adequate knowledge about water and exercise recommendations, although significant percentages of the populations (>40%) did not consume water or exercise in adequate amounts. Knowledge was found to be a component of both behaviors, as it was more prevalent in the adults who exercised and consumed water in adequate amounts. Analysis of variance revealed no significant difference between overall beverage calorie percentage and exercise level (all p-values > 0.05); both regions and genders reported ∼18% of total caloric intake from beverages. There was no disproportionate influence of beverage calories on total caloric intake, after controlling for water consumption and independent of exercise behavior. These findings suggest that overall caloric intake, from both foods and beverages, may be the most influential factor to the energy imbalance contributing to the obesity crisis in these Hispanic border populations. ^
Resumo:
High-risk injection drug use and the sexual behaviors that accompany it have large social and financial costs. Tailored treatments have been shown to successfully reduce high-risk behaviors. However, little is known about how age and age at first drug use are related to high-risk injection or sex behaviors. The current study draws on life course theory and hypothesizes that age will have a strong relationship with high-risk behaviors of out-of-treatment drug users. Data from the NIDA Cooperative Agreement was used to analyze the relationship between (1) age, and (2) age at first drug use with seven high-risk injection and sexual behavior variables. Negative binomial regression models revealed that high-risk sexual behavior decreases between 15.8 and 20.9% with each decade of age, while high-risk injection behavior increases between 32 and 67% with each decade of age after the addition of demographic controls. Both high-risk injection and high-risk sex behaviors are significantly reduced with a delayed age at first drug use. Previous research promotes interventions to reduce the high-risk sexual behaviors of older drug users. The current study suggests a refocusing of public health efforts on the high-risk injection habits of older drug users.^
Resumo:
Background. Previous research shows inconsistent results as to the association between part-time employment and sexual behavior among younger teens. Studies of older teens cannot be generalized to younger teens because of the wide differences in types of work performed, nature of work environments, and work intensity. Objective. Examine the relationship between part-time employment and sexual behavior in a cross-sectional sample of public middle school students in Houston, Texas. Methods . The study presents a secondary analysis of data from the It’s Your Game…Keep it Real baseline data collection (11/2004–1/2005). It’s Your Game… is an intervention program for middle school students designed to prevent Sexually Transmitted Infections. Statistical analysis. Univariate and multivariate logistic regression analyses were conducted to examine the association between part-time employment and vaginal intercourse: (a) ever had sex; and (b) current sexual activity. Results. Overall, 13.2% of students worked for pay; male students were 1.5 times as likely as females to be working. Of all the students, 11.0% had had sexual intercourse; students who worked were 3 times more likely to be sexually experienced than those who did not. Among students who were sexually experienced, 67.0% were currently sexually active. After adjusting for the other covariates, Hispanic students were almost 3.6 times more likely to report current sexual activity compared to students in other racial/ethnic groups. In univariate analysis, students who worked 1-5 hrs/week were more likely to be sexually experienced than those not currently employed, and the likelihood increased with number of hours worked. There is a similar pattern in the multivariate model, but the odds ratios are too close for the evidence to be more than suggestive. Of sexually experienced students, students working 1-5 hrs/week were 2.7 times more likely to report current sexual intercourse than those not working; those working >5 hrs/week were 4.7 times more likely. The multivariate model showed a similar increase in likelihood, and adjustment for covariates increased these associations: students who worked 1-5 hrs/week were 3.6 times more likely to report current sexual intercourse, and students who worked >5 hrs/week were 4.5 times more likely, than students not currently employed.^
Resumo:
The use of feminine products such as vaginal douches, tampons, and sanitary napkins are common among women. Despite the results of some studies that suggest an association between douching and bacterial vaginosis, douching remains a topic that is understudied. The possibility of an association between tampon use and infection has not been significantly investigated since the toxic shock outbreak in the 1980s. The first objective of our study was to evaluate demographic, reproductive health, and sexual behavior variables to establish an epidemiologic profile of menstruating women who reported douching and women who reported using sanitary napkins only. The second objective of our study was to evaluate whether the behaviors of douching and using tampons were associated with an increased risk of bacterial vaginosis or trichomonas. We analyzed these factors, using logistic regression, among the 3,174 women from the NHANES cross sectional data from 2001-2004, who met the inclusion criteria determined for our study. We established an epidemiologic profile for women who had the highest frequency of douching reported as women who were age 36-49, had a high school education or GED, black race, not taking oral contraceptives, reported vaginal symptoms in the last month, two or more sexual partners in the last year, or tested positive for bacterial vaginosis or trichomonas. The profile for those who had the highest frequency of exclusive sanitary napkin use included women with less than a high school education, married women, women classified as black or "other" in race, and women who were not on oral contraceptives. While we were able to establish a significant increase in the odds of douching among women who tested positive for bacterial vaginosis or trichomonas, we did not find any significant difference in the odds of exclusive napkin use and testing negative for bacterial vaginosis or trichomonas.^