Condom Use Trajectories in Adolescence and the Transition to Adulthood: The Role of Mother and Father Support

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92028/1/jora775.pd

Substance Use Prevention Services in Juvenile Justice and Behavioral Health: Results from a National Survey

BACKGROUND: This study examined the national availability of substance use prevention (SUP) within juvenile justice (JJ) and their primary behavioral health (BH) providers, and the relationships between the availability of SUP and agency-level measures of organizational structure, staffing, and youth characteristics. A three-stage national probability sampling process was used to select participants for a national survey that included, among other facets of community supervision (CS) and BH practices, questions on agency characteristics, youth characteristics, whether the agency/provider directly provided SUP services, and whether the agency/provider directly provided substance use and/or mental health treatment. This paper focuses on SUP services along with agency/provider and youth characteristics related to providing SUP. RESULTS: The response rate for both CS agencies (n = 195) and BH providers (n = 271) was 96%. Complex samples logistic regression initially examined univariate associations of each variable and identified candidates for a final multivariate model. Overall, only one-third of CS and BH providers reported offering SUP services, with BH providers being significantly more likely than CS agencies to provide SUP services. In addition, likelihood of SUP was significantly lower among agencies where the substance use distribution of the caseload was below the median. Controlling for master\u27s level staff and the substance use distribution, CS agencies were about 67% less likely to offer SUP when compared to BH providers. CONCLUSIONS: Given the high rates of substance use among justice-involved youth and that substance use is an established risk for several negative behaviors, outcomes, and health conditions, these findings suggest that evidence-based prevention services should likely be expanded in justice settings, and perhaps included as part of CS programs, even when youth do not initially present with SU service needs

Perceived Mental Illness Stigma Among Youth in Psychiatric Outpatient Treatment

This research explores the experiences of mental illness stigma in 24 youth (58.3% male, 13–24 years, 75% Latino) in psychiatric outpatient treatment. Using Link and Phelan’s (2001) model of stigmatization, we conducted thematic analysis of the interview texts, examining experiences of stigma at individual and structural levels, in addition to the youths’ social-psychological processes. Youth in psychiatric treatment acknowledged that their larger cultural context holds pejorative viewpoints toward those with mental illness and reported experiences of stigma within their families and social networks. Our results also offer insight into the social-psychological processes of stigma, highlighting how labeling may influence their self-concept and the strategies in which youth engage to manage a stigmatized identity. We discuss differences in stigma experiences by gender, age, and diagnosis. Findings provide new information on the stigma experiences of youth in psychiatric treatment and suggest that a multilevel approach to reduce stigma is warranted

Individual and Contextual Factors of Sexual Risk Behavior in Youth Perinatally Infected with HIV

Abstract This study prospectively examines the effects of maternal and child HIV infection on youth penetrative and unprotected penetrative sex, as well as the role of internal contextual, external contextual, social and self-regulatory factors in influencing the sexual behaviors of HIV?infected (PHIV+), HIV?affected (uninfected with an HIV+ caregiver), and HIV unaffected (uninfected with an HIV? caregiver) youth over time. Data (N=420) were drawn from two longitudinal studies focused on the effects of pediatric or maternal HIV on youth (51% female; 39% PHIV+) and their caregivers (92% female; 46% HIV+). PHIV+ youth were significantly less likely to engage in penetrative sex than HIV? youth at follow-up, after adjusting for contextual, social, and self-regulatory factors. Other individual- and contextual-level factors such as youth alcohol and marijuana use, residing with a biological parent, caregiver employment, caregiver marijuana use, and youth self-concept were also associated with penetrative sex. Youth who used alcohol were significantly more likely to engage in unprotected penetrative sex. Data suggest that, despite contextual, social, and self-regulatory risk factors, PHIV+ youth are less likely to engage in sexual behavior compared to HIV? youth from similar environments. Further research is required to understand delays in sexual activity in PHIV+ youth and also to understand potential factors that promote resiliency, particularly as they age into older adolescence and young adulthood.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98470/1/apc%2E2012%2E0005.pd

A model for adapting evidence-based behavioral interventions to a new culture: HIV prevention for psychiatric patients in Rio de Janeiro, Brazil

As in other countries worldwide, adults with severe mental illness in Brazil have elevated rates of HIV infection relative to the general population. However, no HIV prevention interventions have been tested for efficacy with psychiatric patients in Brazil. We conducted participatory research with local providers, community leaders, patient advocates, and patients using an intervention adaptation process designed to balance fidelity to efficacious interventions developed elsewhere with fit to a new context and culture. Our process for adapting these interventions comprised four steps: (1) optimizing fidelity; (2) optimizing fit; (3) balancing fidelity and fit; and (4) pilot testing and refining the intervention. This paper describes how these steps were carried out to produce a Brazilian HIV prevention intervention for people with severe mental illness. Our process may serve as a model for adapting existing efficacious interventions to new groups and cultures, whether at a local, national, or international level

The Dynamic Impact of Large Wind Farms on Power System Stability

As the installed capacity of wind power increases across the world, its impact on power systems is becoming more important. To ensure the reliable operation of a power system which is significantly fed by wind power, the dynamics of the system must be understood. The purpose of this study is to analyse the dynamic impact of large-scale wind farms on the stability of a power grid, and to investigate the possibility of improving the stabilisation and damping of the grid by smart control strategies for wind turbines. When unconventional types of generators are used in a power system, the system behaves differently under abnormal dynamic events. For example, new types of generators such as doubly fed induction generators (DFIGs) cause different modes of oscillation in the system. In order to damp oscillations in the system, it is necessary to understand the equipment causing these oscillations, and the methods of optimally damping the oscillations. Large power oscillations can occur in a power system as a result of disturbances. Ordinarily these oscillations are slow and, in principle, it is possible to damp them with the help of wind power. This suggests the use of a power oscillation damping (POD) controller for a DFIG, similar to a power system stabiliser (PSS) for a synchronous generator. To demonstrate this concept, we design PODs for DFIGs in a wind farm. Voltage stability is another important aspect of the safe operation of a power system. It has been shown that the voltage stability of a power system is affected by induction generators and also DFIGs. The voltage stability must therefore also be analysed in order to guard against a power system collapse. In this study we develop models and control strategies for large wind farms comprising DFIGs, and study the impact of the wind farms on power systems. The design of multiple PODs in a wind farm is performed using linear matrix inequalities (LMIs), and the impact of the wind turbines is investigated through the use of linear and dynamic simulations. It has been demonstrated that DFIGs can be used for damping oscillations, and that they can also improve the critical clearing time of some faults. However, they may have an adverse impact on power systems after large voltage disturbances.QC 2012041

On the Use of Wind Power for Transient Stability Enhancement of Power Systems

This report deals with the impact of doubly fed induction generators on the stability of a power system. The impact was quantified by means of detailed numerical simulations. The report contains a full description of the simulation, and details of the small signal analysis performed to analyse the system. Before the simulation results are presented, a foundation is laid, explaining the theory required to understand the models used and the calculations performed in the simulation. The derivation of a model of a doubly fed induction generator is presented, along with a description of the model of a synchronous generator. These are used in the simulation and analysis of a multi-machine power system, consisting of both of these types of generators. An explanation of how dynamic simulations of power systems can be performed is also put forward. This is useful, not only for understanding the simulation performed for this report, but as a guide to performing simulations of this type. This is true also for a description of linearisation and small signal analysis contained in this report. The software package MATLAB is used to perform the simulations, and the small signal analysis. Since the method described in this report is very general, it can be used to perform similar power system simulations for other power systems, and with other software. Numerical simulations reveal that the addition of doubly fed generators, such as those in wind parks, to a power system improves the response of the system after small disturbances, but can worsen it after larger disturbances

Wind power stabilising control : Demonstration on the Nordic grid

When unconventional types of generators such as doubly fed induction generators (DFIGs) are used in a power system, the system behaves differently under abnormal dynamic events. For example, DFIGs cause different modes of oscillation in the power system, and respond differently to changes in voltage. In order to damp oscillations in the system, it is necessary to understand the equipment causing these oscillations, and the methods of optimally damping the oscillations. Large power oscillations can occur in a power system as a result of disturbances. Ordinarily these oscillations are slow and, in principle, it is possible to damp them with the help of wind power. This suggests the use of a power oscillation damping (POD) controller for a DFIG, similar to a power system stabiliser (PSS) for a synchronous generator. Voltage stability is another important aspect of the safe operation of a power system. It has been shown that the voltage stability of a power system is affected by induction generators and also DFIGs, and we investigate some aspects of this here. In this study we develop control strategies for large wind farms comprising DFIGs, and study the impact of the wind farms on a system which is designed to reflect the dynamics of the Nordic power system. The design of multiple PODs in a wind farm is undertaken using linear matrix inequalities (LMIs). The impact of the wind turbines is investigated through the use of linear and dynamic simulations. It has been demonstrated that DFIG-based wind farms can be used for damping oscillations, even when they are not producing their rated power, and that they can also improve the critical clearing time of some faults. However, they may have an adverse impact on power systems after large voltage disturbances.QC 2012040

Modelling and Control of Doubly Fed Induction Generators in Power Systems : Towards understanding the impact of large wind parks on power system stability

The rapid development of wind power technology is reshaping conventional power grids in many countries across the world. As the installed capacity of wind power increases, its impact on power grids is becoming more important. To ensure the reliable operation of a power system which is significantly fed by wind power, the dynamics of the power system must be understood, and the purpose of this study is to develop suitable analytical tools for analysing the dynamic impact of large-scale wind parks on the stability of a power grid, and to investigate the possibility of improving the stabilisation and damping of the grid by smart control strategies for wind turbines.Many of the newer, larger turbines now being produced are variable speed turbines, which use doubly fed induction generators (DFIGs). These are induction generators which have their stator and rotor independently excited. When unconventional generators of this type are used in a power system, the system behaves differently under abnormal dynamic events.  For example, new types of generators cause different modes of oscillation in the power system, not only because of their dynamic characteristics, but also because they load the system differently.Very large power oscillations can occur in a power system as a result of internal disturbances.  Ordinarily these oscillations are slow and, in principle, it is possible to damp them with the help of wind power.  This leads to the idea of using a power system stabiliser (PSS) for a DFIG.  In order to damp oscillations in the system, it is necessary to understand the equipment causing these oscillations, and the methods to optimally damp the oscillations.Voltage stability is another important aspect of the safe operation of a power system. It has been shown that the voltage stability of a power system is affected by induction generators.  The voltage stability must therefore be carefully analysed in order to guard against a power system collapse.By using modal analysis and dynamic simulations, we show that the presence of a wind farm in the vicinity of a power system will improve the angular behaviour of the power system under small disturbances, but may decrease voltage stability under larger disturbances. We compare the performance of wind turbines to that of conventional synchronous generator power plants, and we show that a wind park consisting of DFIGs, which are equipped with PSSs, may be used as a positive contribution to power system damping