Dealing with Moms and Dads: Family Dilemmas Encountered by Youth Program Leaders

The leaders of youth programs encounter a range of challenging situations that involve youth’s parents or families. This qualitative study obtained data on the variety and nature of these family-related “dilemmas of practice.” Longitudinal interviews with leaders of 10 high quality programs for high-school-aged youth yielded narrative information on a sample of 32 family dilemmas that they had encountered. Grounded theory analysis identified four categories of family dilemmas: 1) problems at home that become a concern to the leader, 2) parents’ expectations are incongruent with program norms or functioning, 3) parents do not support youth’s participation in the program or an aspect of the program, and 4) communicating with parents on sensitive matters. Each of these categories of dilemmas entailed distinct considerations and underlying issues that effective leaders need to be able to understand

Youth Worker Reasoning about Dilemmas Encountered in Practice: Expert-Novice Differences

This study examines one aspect of youth worker expertise, the ability to appraise and respond to the dilemmas of practice encountered in youth programs. To understand how expert youth workers differ from novices in their reasoning about these dilemmas, a sample of expert and novice practitioners read vignettes of dilemma situations and described their appraisals of the situations and how they might respond to them. Quantitative analyses confirmed four hypothesized differences between the two groups. Experts identified more considerations in the situations and generated more possible responses. Experts’ responses were also more likely to be youth-centered and address multiple considerations. Qualitative analyses suggested that these differences were attributable to the experts having more elaborate mental models that allowed them to understand varied human systems – individual youth, group dynamics, parents, funders, etc. – and to tailor their responses accordingly. The experts engaged in more forecasting of events, anticipating contingencies, and formulating decision trees that took possible contingencies into account. Although preliminary, the findings have implications for how youth workers are trained

Preliminary catalog of pictures taken on the lunar surface during the Apollo 15 mission

Catalog of all pictures taken from lunar module or lunar surface during Apollo 15 missio

Population III star formation in a Lambda CDM universe, I: The effect of formation redshift and environment on protostellar accretion rate

(abridged) We perform 12 extremely high resolution adaptive mesh refinement cosmological hydrodynamic simulations of Population III star formation in a Lambda CDM universe, varying the box size and large-scale structure, to understand systematic effects in the formation of primordial protostellar cores. We find results that are qualitatively similar to those observed previously. We observe that the threshold halo mass for formation of a Population III protostar does not evolve significantly with time in the redshift range studied (33 > z > 19) but exhibits substantial scatter due to different halo assembly histories: Halos which assembled more slowly develop cooling cores at lower mass than those that assemble more rapidly, in agreement with Yoshida et al. (2003). We do, however, observe significant evolution in the accretion rates of Population III protostars with redshift, with objects that form later having higher maximum accretion rates, with a variation of two orders of magnitude (10^-4 - 10^-2 Msolar/year). This can be explained by considering the evolving virial properties of the halos with redshift and the physics of molecular hydrogen formation at low densities. Our result implies that the mass distribution of Population III stars inferred from their accretion rates may be broader than previously thought, and may evolve with redshift. Finally, we observe that our collapsing protostellar cloud cores do not fragment, consistent with previous results, which suggests that Population III stars which form in halos of mass 10^5 - 10^6 Msun always form in isolation.Comment: Accepted by The Astrophysical Journal. Some minor changes. 65 pages, 3 tables, 21 figures (3 color). To appear in January 1, 2007 issu

New Horizons: Understanding the Processes and Practices of Youth Development

Abstract: This article presents new horizon for research on youth development by focusing on the challenges youth face in learning teamwork and in coming to terms with diversity. These are both essential competencies for navigating the "real world" of the 21 st century. We examine how youth experience these challenges within programs; also how they present second-order challenges to practitioners. The underlying message of this article is that it is essential for researchers to see programs from the point of view of the people in them. Researchers have learned quite a bit of what can be learned from arm's length: that programs can make a difference in youths' lives and that certain features of settings are associated with these changes. To go further, researchers need to work side-by-side with practitioners and youth to understand their complex worlds as they experience them

New Horizons: Understanding the Processes and Practices of Youth Development

This article presents new horizons for research on youth development by focusing on the challenges youth face in learning teamwork and in coming to terms with diversity. These are both essential competencies for navigating the “real world” of the 21st century. We examine how youth experience these challenges within programs; also how they present second-order challenges to practitioners. The underlying message of this article is that it is essential for researchers to see programs from the point of view of the people in them. Researchers have learned quite a bit of what can be learned from arm’s length: that programs can make a difference in youths’ lives and that certain features of settings are associated with these changes. To go further, researchers need to work side-by-side with practitioners and youth to understand their complex worlds as they experience them

The Initial Mass Function as given by the fragmentation

The dichotomy between a universal mass function (IMF) and a variable IMF which depends on local physical parameters characterises observational and theoretical stellar astronomy. In this contribution the available distributions of probability are briefly reviewed. The physical nature of two of them, gamma variate and lognormal, is then explained once the framework of the fragmentation is introduced. Interpolating techniques are then applied to the sample of the first 10 pc and to the open cluster NGC6649: in both cases lognormal distribution produces the best fit. The three power law function has also been investigated and visual comparison with an artificially generated sample of 100000 stars suggests that the variations in the spectral index are simply due to the small number of stars available in the observational sample. In order to derive the sample of masses, a new formula that allows us to express the mass as a function of the absolute magnitude and (B-V) for MAIN V, GIANTS III and SUPERGIANTS I is derived.Comment: 6 pages 9 figure

Formation of Primordial Stars in a LCDM Universe

We study the formation of the first generation of stars in the standard cold dark matter model, using a very high-resolution hydordynamic simulations. Our simulation achieves a dynamic range of 10^{10} in length scale. With accurate treatment of atomic and molecular physics, it allows us to study the chemo-thermal evolution of primordial gas clouds to densities up to n = 10^{16}/cc without assuming any a priori equation of state; a six orders of magnitudes improvement over previous three-dimensional calculations. All the relevant atomic and molecular cooling and heating processes, including cooling by collision-induced continuum emission, are implemented. For calculating optically thick H2 cooling at high densities, we use the Sobolev method. To examine possible gas fragmentation owing to thermal instability, we compute explicitly the growth rate of isobaric perturbations. We show that the cloud core does not fragment in either the low-density or high-density regimes. We also show that the core remains stable against gravitational deformation and fragmentation. We obtain an accurate gas mass accretion rate within a 10 Msun innermost region around the protostar. The protostar is accreting the surrounding hot gas at a rate of 0.001-0.01 Msun/yr. From these findings we conclude that primordial stars formed in early minihalos are massive. We carry out proto-stellar evolution calculations using the obtained accretion rate. The resulting mass of the first star is M_ZAMS = 60-100 Msun, with the exact mass dependent on the actual accretion rate.Comment: 27 pages, 13 embedded figures. Revised versio

Female Sexual Function Index Short Version: A MsFLASH Item Response Analysis

The Female Sexual Function Index (FSFI) is a psychometrically sound and popular 19-item self-report measure, but its length may preclude its use in studies with multiple outcome measures, especially when sexual function is not a primary endpoint. Only one attempt has been made to create a shorter scale, resulting in the Italian FSFI-6, later translated into Spanish and Korean without further psychometric analysis. Our study evaluated whether a subset of items on the 19-item English-language FSFI would perform as well as the full-length FSFI in peri- and post-menopausal women. We used baseline data from 898 peri- and post-menopausal women recruited from multiple communities, ages 42–62 years, and enrolled in randomized controlled trials for vasomotor symptom management. Goals were to (1) create a psychometrically sound, shorter version of the FSFI for use in peri- and post-menopausal women as a continuous measure and (2) compare it to the Italian FSFI-6. Results indicated that a 9-item scale provided more information than the FSFI-6 across a spectrum of sexual functioning, was able to capture sample variability, and showed sufficient range without floor or ceiling effects. All but one of the items from the Italian 6-item version were included in the 9-item version. Most omitted FSFI items focused on frequency of events or experiences. When assessment of sexual function is a secondary endpoint and subject burden related to questionnaire length is a priority, the 9-item FSFI may provide important information about sexual function in English-speaking peri- and post-menopausal women