Individual, Family and Neighborhood Influences on Teen Childbearing: A Life Options Approach

This paper presents results from an examination of the effects of neighborhood and family characteristics—as they are related to an individual’s life options—on the teenage fertility of urban respondents. The study drew upon the life options perspective, a loosely defined theoretical framework which posits that opportunities for social and economic mobility impact an adolescent’s expectations for the future and behavior. The data come from the University of Chicago’s Urban Poverty and Family Life Survey of Chicago. Collected in 1987 under the supervision of William Julius Wilson, the data are derived from 2,490 personal and telephone interviews conducted with a multistage, stratified probability sample of Chicago residents aged 18 to 44 years. Respondents resided in census tracts with 1980 poverty rates of at least 20 percent. These results provide some support for the use of a life options approach to understand teenage childbearing

Promise of Welfare Reform: Development Through Devolution on Indian Reservations

In the 1990s, devolution of authority from federal to states and local governmental institutions in the administration of social welfare policies, programs, and services is seen as an answer to alleviating poverty among low-income families with children. To this effect, the Personal Responsibility and Work Opportunity Reconciliation Act (PRWORA) of 1996 has granted an option to tribal governments to administer their own Temporary Assistance for Needy Families (TANF) services. In this article we provide findings from early experience of tribes within Arizona in their attempt to self-administer TANF services. We collected and analyzed data from multiple sources, including a review of documents provided by the state and tribal members, in-depth telephone interviews with service providers on 15 of the 21 reservations, and site visits to four reservations at which we conducted group interviews with state and tribal social service providers. We found that under the 1996 welfare legislation, tribal governments have greater authority and flexibility to self-administer welfare policies on their reservations, but they are lacking adequate financial and technical resources to exercise these responsibilities effectively. One unintended positive outcome of this legislation is that communication, coordination, and collaboration among tribes, between tribes and states and tribes and the federal government has increased

Optimierung eines Algorithmus zur Berechnung von Exzitoneigenzuständen in einem Kupferoxydul Quantentopf unter Verwendung einer B-Spline Basis

Exzitonen sind Quasiteilchen, die unter anderem durch optische Anregung von Elektronen in Halbleitern entstehen. Sie wurden erstmals im Jahr 1931 von Frenkel und im Jahr 1937 von Wannier theoretisch beschrieben. Der experimentelle Nachweis in Kupferoxydul gelang Hayashi und Katsuki im Jahr 1950. Durch die hohe Rydbergenergie lassen sich Exzitonen in Verbindungen wie Kupferoxydul und GaAs gut untersuchen. Im Jahr 2014 gelang es der Experimentalphysikgruppe von M. Bayer in Dortmund, Exzitonen bis zur Hauptquantenzahl $n =25$ zu detektieren. Dadurch wuchs das Interesse zur Forschung an Rydbergexzitonen in Kupferoxydul. In dieser Arbeit werden Exzitonen in einem unendlich hohen Quantentopf betrachtet, in Anlehnung an Exzitonen in sehr dünnen Kristallschichten oder anderen Nanostrukturen. Durch den Einschluss von Exzitonen in solchen niedrigdimensionalen Halbleiterstrukturen können optische Nichtlinearitäten nutzbar gemacht werden. Die Untersuchung von Exzitonen in solchen Strukturen ist ein entscheidender Schritt, um diese Nichtlinearität für Anwendungen nutzbar zu machen. Für Exzitonen in einem solchen Quantentopf wird in dieser Arbeit das Energiespektrum berechnet, in dem der Hamiltonoperator in einer B-Spline-Basis numerisch diagonalisiert wird. Dabei wird die Bandstruktur vernachlässigt und mit einem wasserstoffartigen Modell gerechnet. Dazu existiert bereits ein von Pavel Belov entwickelter Algorithmus. Leon Kühner nutzte den Algorithmus bereits, um einige Zustände in Abhängigkeit von der Breite des Quantentopf zu bestimmen. Zudem verglich er die numerischen Ergebnisse mit den Ergebnissen von analytisch lösbaren Ansätzen. Ziel dieser Arbeit ist zum einen die Optimierung des ursprünglichen Algorithmus, um bei gleicher Rechenzeit eine bessere Konvergenz zu erzielen. Das optimierte Programm wird verwendet, um das Spektrum in Abhängigkeit von der Breite des Quantentopfs zu berechnen und zu analysieren. Zudem werden mithilfe der Stabilization Method auch die Positionen und Linienbreiten von Resonanzzuständen oberhalb der Kontninuumsschwelle berechnet

Resonance energies and linewidths of Rydberg excitons in Cu2_2O quantum wells

Rydberg excitons are the solid-state analog of Rydberg atoms and can, e.g., for cuprous oxide, easily reach a large size in the region of $\mu$m for principal quantum numbers up to $n=25$. The fabrication of quantum well-like structures in the crystal leads to quantum confinement effects and opens the possibility to study a crossover from three-dimensional to two-dimensional excitons. For small widths of the quantum well (QW) there are several well separated Rydberg series between various scattering thresholds leading to the occurrence of electron-hole resonances with finite lifetimes above the lowest threshold. By application of the stabilization method to the parametric dependencies of the real-valued eigenvalues of the original three-dimensional Schr\"{o}dinger equation we calculate the resonance energies and linewidths for Rydberg excitons in QWs in regimes where a perturbative treatment is impossible. The positions and finite linewidths of resonances at energies above the third threshold are compared with the complex resonance energies obtained within the framework of the complex-coordinate-rotation technique. The excellent agreement between the results demonstrates the validity of both methods for intermediate sizes of the QW-like structures, and thus for arbitrary widths.Comment: 10 pages, 4 figures, accepted for publication in Phys. Rev.

Tribal/State Title IV-E Intergovernmental Agreements, Facilitating Tribal Access to Federal Resources

Although Title IV-E of the Social Security Act is an important funding stream for foster care and adoption services in American Indian communities, limited research has been conducted on the facilitation of tribal access to federal IV-E resources. Historically, direct IV-E funding has not been available to tribal communities, therefore, tribes have worked with their respective states to develop agreements that allow them to access these important funds. The purpose of this study was to provide a comprehensive overview of current IV-E intergovernmental provisions in order to assist tribes and states in strengthening both new and existing IV-E agreements. The research team conducted a nationwide content analysis of all existing current IV-E documents and conducted focus groups and telephone interviews with tribal and state representatives. Major findings include: 1) current IV-E tribal/ state agreements vary widely, thus, there is no “standard” for these agreements; 2) current IV-E tribal/state agreements focus mainly on foster care maintenance payments and services; and 3) although tribes have limited options in regard to accessing IV-E dollars (tribes must enter into an agreement with the state or they cannot access this funding source), they have established good working relationships with their respective states. Implications of these results for both tribes and states are discussed, and three recommendations are included to help facilitate tribal access to Title IV-E federal funding

Factors Influencing African American Youths\u27 Decisions to Stay in School

Little attention has been given to the non-problematic development and positive life decisions of African American youth. This paper reports findings of 231 African American students. The goal of the study was to assess factors which contribute to their academic grade point averages and intentions to stay in school. The conceptual model employed in this study was the Theory of Planned Behavior (TPB) which contends that intentions to carryout a behavior is a function of Attitude towards the behavior, Social Normative support for undertaking the behavior, and the Perceived Control of being able to carry out the behavior. In addition to the TPB components, the contributions of self-esteem and racial self-esteem were also examined for their influence on academic strivings. The TPB model did predict well student’s intentions to stay in school, but predicted less well student grade point averages. Self-esteem was also a significant predictor of intentions to stay in school, but was not a significant predictor of gpa. Racial self-esteem was observed to be only marginally significant, but as predicted, was negatively associated with student Intentions to stay in school. However racial self esteem was not observed to be a significant predictor of student gpa. Hence students with positive self-esteem, who have favorable attitudes towards school and perceive fewer barriers to completing school are most likely to do so. But, the negative association between racial self-esteem and academic intentions suggests that some African American youths may need be convinced that academic success is not an act of racial betrayal

Implementation of the Temporary Assistance for Needy Families (TANF) on American Indian Reservations: Early Evidence from Arizona

This study is aimed at monitoring the impact of the 1996 federal welfare legislation on American Indian families with children on reservations within the state of Arizona over five years (1997-2002). Our goal is to inform the public policy debate on how to improve the social and economic opportunities for low-income families with children on reservations. This report is based on our first year (October 1, 1997-September 30,1998) of work, which focused on aspects of reform implementation and short-term and potential long-term outcomes. We analyzed secondary data from administrative sources relevant to the implementation of welfare legislation in Indian communities. In addition, we collected and analyzed primary (qualitative) data regarding welfare reform options implemented on reservations and their potential impacts. Primary data were collected from in-depth telephone interviews with service providers of 15 of the 21 reservations in Arizona. This information was substantiated by two site visits to three reservations where we conducted focus groups with current and former welfare recipients and state and tribal social service providers

Energy states of Rydberg excitons in finite crystals: From weak to strong confinement

Due to quantum confinement, excitons in finite-sized crystals behave rather differently than in bulk materials. We investigate the dependence of energies of Rydberg excitons on the strengths of parabolic as well as rectangular confinement potentials in finite-sized crystals. The evolution of the energy levels of hydrogen-like excitons in the crossover region from weak to strong parabolic confinement is analyzed for different quantum numbers by numerical solution of the two-dimensional Schr\"{o}dinger equation. The energy spectrum of hydrogen-like excitons in Cu$_{2}$O-based rectangular quantum wells is, in turn, obtained numerically from the solution of the three-dimensional Schr\"{o}dinger equation as a function of the quantum well width. Various crossings and avoided crossings of Rydberg energy levels are observed and categorized based on the symmetry properties of the exciton wave function. Particular attention is paid to the two limiting cases of narrow and wide quantum wells attributed to strong and weak confinement, respectively. The energies obtained with the pure Coulomb interaction are compared with the results originating from the Rytova-Keldysh potential, i.e., by taking into account the dielectric contrast in the quantum well and in the barrier.Comment: 19 pages, 8 figures, accepted for publication in PRB; there are some amendments and minor improvements of the original versio

Examining the Moderating Role of Rational-Versus Emotional-Focused Websites: The Case of Boutique Hotels

This article examines whether emotional or rational advertising appeals are more effective for website hospitality services. Specifically, it considers how attitudes towards websites, service expectations and attitudes towards boutique hotels may influence the two different types of advertising appeals and purchase intention. Results show that websites using emotional appeals tend to show a positive relationship between attitude towards hotels and attitude towards websites and purchase intention. It also indicates that emotional advertisements are better at gaining and retaining interest and attention, and as such can be highly beneficial for small boutique hotels. This article provides several marketing and business policy implications to aid practitioners and strategists in making better decisions