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Dark Matter (DM) subhalos are predicted to perturb stellar streams; stream morphologies and dynamics can constrain the mass distribution of subhalos. Using FIRE-2 simulations of Milky Way-mass galaxies, we show that presence of a Large Magellanic Cloud (LMC)--analog significantly changes stream-subhalo encounter rates. Three key factors drive these changes. First, the LMC--analog brings in many subhalos, increasing encounter rates for streams near the massive satellite by up to 20--40%. Second, the LMC--analog displaces the host from its center-of-mass (inducing reflex motion), causing a north-south asymmetry in the density and radial velocity distribution of subhalos. This asymmetry results in encounter rates varying by 50--70% across the sky at the same distance. Finally, the LMC--mass satellite induces a density wake in the host's DM halo, further boosting the encounter rates near the LMC--analog. We also explore the influence of stream orbital properties, finding a 50% increase in encounters for streams moving retrograde to the LMC--analog's orbit in the opposite hemisphere. The dependence of encounter rates on stream location and orbit has important implications for where to search for new streams with spurs and gaps in the Milky Way., Comment: 28 pages, 17 figures, 3 tables, Accepted in APJ

A variety of observational campaigns seek to test dark-matter models by measuring dark-matter subhaloes at low masses. Despite their predicted lack of stars, these subhaloes may be detectable through gravitational lensing or via their gravitational perturbations on stellar streams. To set measurable expectations for subhalo populations within LambdaCDM, we examine 11 Milky Way (MW)-mass haloes from the FIRE-2 baryonic simulations, quantifying the counts and orbital fluxes for subhaloes with properties relevant to stellar stream interactions: masses down to 10^6 Msun, distances < 50 kpc of the galactic center, across z = 0 - 1 (lookback time 0 - 8 Gyr). We provide fits to our results and their dependence on subhalo mass, distance, and lookback time, for use in (semi)analytic models. A typical MW-mass halo contains ~16 subhaloes >10^7 Msun (~1 subhalo >10^8 Msun) within 50 kpc at z = 0. We compare our results with dark-matter-only versions of the same simulations: because they lack a central galaxy potential, they overpredict subhalo counts by 2-10x, more so at smaller distances. Subhalo counts around a given MW-mass galaxy declined over time, being ~10x higher at z = 1 than at z = 0. Subhaloes have nearly isotropic orbital velocity distributions at z = 0. Across our simulations, we also identified 4 analogs of Large Magellanic Cloud satellite passages; these analogs enhance subhalo counts by 1.4-2.7 times, significantly increasing the expected subhalo population around the MW today. Our results imply an interaction rate of ~5 per Gyr for a stream like GD-1, sufficient to make subhalo-stream interactions a promising method of measuring dark subhaloes., Comment: 14 pages, Published in MNRAS

Compact stars containing quark matter may masquerade as neutron stars in the range of measured mass and radius, making it difficult to draw firm conclusions on the phase of matter inside the star. The sensitivity of core $g$-mode oscillations to the presence of a mixed phase may alleviate this difficulty. In hybrid stars that admit quark matter in a mixed phase, the $g$-mode frequency rises sharply due to a marked decrease in the equilibrium sound speed. Resonant excitation of $g$-modes can leave an imprint on the waveform of coalescing binary compact stars. We present some analytic and numeric results to assess the sensitivity displayed by $g$-mode oscillations to quark matter in a homogeneous or mixed phase and find that the $g$-mode can probe the fraction of quark matter inside the star., Comment: 11 pages, 6 figures

Some of the nation's most vulnerable youth are those living in foster care and other out-of-home settings. Many such youth have experienced abuse and neglect, face mental health and substance abuse challenges, and struggle with serious behavioral problems (Casanueva et al. 2014). They are more likely than their peers to have academic struggles and less likely to graduate from high school or attend college (Dworsky et al. 2014). In part for these reasons, they also have higher rates of teen pregnancy, sexually transmitted infections (STIs), and associated sexual risk behaviors. Estimates suggest that as many as one in three girls in foster care will become a teen mother--a rate more than double the national average (Dworsky and Courtney 2010). Of those who become mothers before age 18, more than one in four will go on to have another child before aging out of their teens (Putnam-Hornstein and King 2014). This report presents interim findings from a large-scale demonstration project and evaluation of the POWER Through Choices (PTC) program, a comprehensive sexual health education curriculum designed specifically for youth in foster care and other out-of-home care settings. The program features ten 90-minute sessions delivered to small groups of youth by trained facilitators in a classroom-based setting. This curriculum-based structure is similar to many teen pregnancy prevention programs delivered to general youth populations in schools and community settings. The PTC program is unique, however, in addressing the needs and risk factors specific to youth in foster care and other out-of-home care settings. Findings from an implementation study of the PTC program were presented in an earlier report (Meckstroth et al. 2014). The present report adds to these findings by describing the short-term impacts of the PTC program on youth knowledge, attitudes, and intentions. A future report will examine the program's longer-term impacts on youth sexual risk behaviors. The following are appended: (1) Nonresponse Analysis; (2) Outcome Measures; and (3) Sensitivity Analyses.

During the "WISE at 5: Legacy and Prospects" conference in Pasadena, CA -- which ran from February 10 - 12, 2015 -- attendees were invited to engage in an interactive session exploring the future uses of the Wide-field Infrared Survey Explorer (WISE) data. The 65 participants -- many of whom are extensive users of the data -- brainstormed the top questions still to be answered by the mission, as well as the complementary current and future datasets and additional processing of WISE/NEOWISE data that would aid in addressing these most important scientific questions. The results were mainly bifurcated between topics related to extragalactic studies (e.g. AGN, QSOs) and substellar mass objects. In summary, participants found that complementing WISE/NEOWISE data with cross-correlated multiwavelength surveys (e.g. SDSS, Pan-STARRS, LSST, Gaia, Euclid, etc.) would be highly beneficial for all future mission goals. Moreover, developing or implementing machine-learning tools to comb through and understand cross-correlated data was often mentioned for future uses. Finally, attendees agreed that additional processing of the data such as co-adding WISE and NEOWISE and extracting a multi-epoch photometric database and parallax and proper motion catalog would greatly improve the scientific results of the most important projects identified. In that respect, a project such as MaxWISE which would execute the most important additional processing and extraction as well as make the data and catalogs easily accessible via a public portal was deemed extremely important., Comment: 10 pages, 6 figures

Mental disorders are diagnosable conditions characterized by changes in thinking, mood, or behavior (or some combination of these) that can cause a person to feel stressed out and impair his or her ability to function. These disorders are common in adolescence. This "Adolescent Health Highlight" presents the warning signs of mental disorders; describes the types of mental disorders and their prevalence and trends; discusses the consequences and risk of mental disorders; presents treatment options and barriers to accessing mental health care; and provides mental health resources. (Contains 2 figures and 16 resources.)

A substantial proportion of high school students consume alcohol, with nearly a quarter of 12th grade students reporting binge drinking in the past two weeks. Drinking alcohol in adolescence is associated with a variety of other risky behaviors, as well as with an increased likelihood of long-term problems reaching into adulthood. This "Adolescent Health Highlight" summarizes key research findings about adolescent alcohol consumption; describes prevalence and trends; illustrates connections between behaviors and health outcomes; and discusses issues specific to particular adolescent populations. Fast facts about alcohol use include: (1) More adolescents drink alcohol than smoke cigarettes or use marijuana, combined; (2) Forty percent of high school seniors reported drinking some alcohol within the past 30 days; (3) In addition, 22 percent of high school seniors reported that they had engaged in "binge drinking" in the past two weeks; (4) Motor vehicle crashes are a leading cause of death for adolescents, and are the most prevalent cause of death for 15- to 24-year-olds. In 2010, about one in five young drivers (ages 16-20) involved in fatal crashes had been driving while alcohol-impaired; and (5) Certain groups of adolescents are most at risk for abusing alcohol: males, those who begin drinking at an early age, those who have a family history of alcohol abuse, and those who have experienced exceptional stress. (Contains 3 figures and 5 resources.)

Cigarette smoking has steadily declined among adolescents during the last fifteen years, although use of some tobacco products, like cigars, has seen recent increases. However, large numbers of teens continue to use tobacco products. This "Adolescent Health Highlight" presents key research findings; describes prevalence and trends; illustrates connections between behaviors and health outcomes; and discusses issues specific to particular adolescent populations. Fast facts about tobacco use include: (1) Cigarette smoking by adolescents has declined by more than half since the peak years of 1996-1997. In 2011, about one in eight adolescents (12 percent) reported smoking in the past 30 days, compared with more than one in four (28 percent) in 1996-1997; (2) More than 7.9 million young people between the ages of 12 and 20 currently use some form of tobacco; (3) Use of cigars and smokeless tobacco products (snuff, chewing tobacco) among adolescents has always been much less common than cigarette smoking, but has experienced a slight increase in recent years; (4) Research points to multiple factors that lead to tobacco addiction in adolescence, from genetics, to influences of parents and peers, to difficult life circumstances; and (5) Tobacco interventions that have been found to work include school and community-based tobacco-use prevention programs; community-wide efforts to prevent the sale of cigarettes and tobacco products to minors; mass media campaigns that highlight the risks of tobacco use; and federal policies to curb the illegal sale of cigarettes. (Contains 4 figures and 4 resources.)