How fast do Jupiters grow? Signatures of the snowline and growth rate in the distribution of gas giant planets

We present here observational evidence that the snowline plays a significant role in the formation and evolution of gas giant planets. When considering the population of observed exoplanets, we find a boundary in mass-semimajor axis space that suggests planets are preferentially found beyond the snowline prior to undergoing gap-opening inward migration and associated gas accretion. This is consistent with theoretical models suggesting that sudden changes in opacity -- as would occur at the snowline -- can influence core migration. Furthermore, population synthesis modelling suggests that this boundary implies that gas giant planets accrete ~ 70 % of the inward flowing gas, allowing ~ 30$ % through to the inner disc. This is qualitatively consistent with observations of transition discs suggesting the presence of inner holes, despite there being ongoing gas accretion.Comment: 7 pages, 6 figures, accepted for publication in Monthly Notices of the Royal Astronomical Societ

The Making of the Classic Period of the Long Black Power Movement in Los Angeles, California

It is often believed that the Black Power Movement started after civil rights/black power activist Stokely Carmichael declared, “We want Black Power” in Greenwood, Mississippi on June 16, 1966 and ended in the 1970s. Similar to the Civil Rights Movement the Black Power Movement is often examined through a dominant narrative short movement view. Some scholars suggests that “Black Power” stood for a change in direction away from the nonviolent civil rights approach. But Black Power is an enigma and it means different things to different people. It is just one element of the Black Freedom Struggle. Black Power uses many methods to liberate Black people from oppression. It shares some of the same methods and goals with the Civil Rights Movement. However, there is one major difference. Unlike the nonviolent struggle for civil rights, participants of Black Power are not opposed to meeting state sanctioned violence with violence. Drawing on both primary and secondary sources, this dissertation challenges the idea of a dominant narrative short Black Power Movement in Los Angeles, California. Although Black Power and the Black Power Movement are experienced in cities across the nation this study is being undertaken because African American participation in Black Power in Los Angeles is often overlooked. Rebellions in many cities outside of the South during the 1960s may have appeared to come out of nowhere to people outside of the Black communities. However, to people in the Black community those storms were a long time in the making. In the first half of the twentieth-century the United States government created policies that limited where Black people could participate in home ownership. Those policies maintained grading systems based on a government created myth that Black people lowered property values, which added more value to white neighborhoods. Those lower-ratings also promoted the idea that Black neighborhoods had more crime, which resulted in over policing. In Los Angeles that over policing involved the Los Angeles Police Department (LAPD), the Sheriffs Department, and the Federal Bureau of Investigation (FBI). The use of Black Power and the development of the Black Power Movement in Los Angeles, California during the twentieth-century are examined in chapter one through governmental housing policies that imposed spatial restrictions on the movement of Black people. In the second chapter I examine the importance of pre1960s incidents of state approved brutality that occurred within the walls of Black communities both locally and nationally. In chapter three I examine the growing popularity and power of the Nation of Islam in Los Angeles and its history of resistance and how that impacted the Black community. In this chapter I also address the importance of the years between 1955 and 1960 in establishing the classic period of Black Power Movement in Los Angeles. Chapter four examines significant events in the early stages of the “classic” period 1961-1971 of the Black Power Movement in Los Angeles. Incidents involving the Nation of Islam and the LAPD play a major role in this examination because of the organization’s resistance or appearance of resistance to police brutality. Chapter five investigates what led up to the Watts Rebellion and what happened to the Movement in its aftermath. I address why Watts is not the beginning of the Movement and suggest it is the second part of the “classic” period of the Black Power Movement in Los Angeles. Chapter six exposes the continuing abuses committed by local law enforcement agencies and the federal government’s covert operations directed against the Black community, Black Power organizations, and Black students in academia. This chapter reveals some of the factors that led to the demise of the “classic” period of the Black Power Movement in Los Angeles

Mortality from infectious pneumonia in metal workers: a comparison with deaths from asthma in occupations exposed to respiratory sensitizers

Introduction: national analyses of mortality in England and Wales have repeatedly shown excess deaths from pneumonia in welders. During 1979-1990 the excess was attributable largely to deaths from lobar pneumonia and pneumonias other than bronchopneumonia, limited to working-aged men, and apparent in other metal fume-exposed occupations. We assessed findings for 1991-2000 and compared the mortality pattern with that from asthma in occupations exposed to known respiratory sensitizers.Methods: the Office of National Statistics supplied data on deaths by underlying cause among men aged 16-74 years in England and Wales during 1991-2000, including age and last held occupation. We abstracted data on pneumonia for occupations with exposure to metal fume and on asthma for occupations commonly reported to surveillance schemes as at risk of occupational asthma. We estimated expected numbers of deaths by applying age-specific proportions of deaths by cause in the population to the total deaths by age in each occupational group. Observed and expected numbers were compared for each cause of death.Results: among working-aged men in metal fume-exposed occupations we found excesses of mortality from pneumococcal and lobar pneumonia (54 deaths vs. 27.3 expected) and from pneumonias other than bronchopneumonia (71 vs. 52.4), but no excess from these causes at older ages, or from bronchopneumonia at any age. The attributable mortality from metal fume (45.3 excess deaths) compared with an estimated 62.6 deaths from occupational asthma.Conclusion: exposure to metal fume is a material cause of occupational mortality. The hazard deserves far more attention than it presently receive

Continuous Physicochemical Monitoring and Modeling of an Aquatic Ecosystem

Chemistr

Sound and Waves: An Integrated K–8 Hands‐On Approach Supporting the NGSS and CCSS ELA

Receive practical ideas to build understanding about how to combine reading and hands-on activities as tools to understand the nature of wave movement

Motivation for Physical Training in Army ROTC Cadets

The present study used Self-Determination Theory to study motivation for physical training (PT) in ARMY ROTC cadets (n=139). Results found that length of participation in ROTC lowered cadets’ intrinsic motivation, which then resulted in lower levels of enjoyment for PT. Application of results for future training is discussed

Vegetation and environmental patterns on soils derived from Hawkesbury Sandstone and Narrabeen substrata in Ku-ring-gai Chase National Park, New South Wales

[Abstract]: The vegetation patterns in the Central Coast region of New South Wales have been extensively studied with respect to single environmental variables, particularly soil nutrients. However, few data are available on the effects of multiple environmental variables. This study examines the relationships between vegetation and multiple environmental variables in natural vegetation on two underlying rock types, Hawkesbury sandstone and Narrabeen group shales and sandstones, in Ku-ring-gai Chase National Park, Sydney. Floristic composition and 17 environmental factors were characterized using duplicate 500 m2 quadrats from fifty sites representing a wide range of vegetation types. The patterns in vegetation and environmental factors were examined through multivariate analyses: indicator species analysis was used to provide an objective classification of plant community types, and the relationships between vegetation and environmental factors within the two soil types were examined through indirect and direct gradient analyses. Eleven plant communities were identified, which showed strong agreement with previous studies. The measured environmental factors showed strong correlations with vegetation patterns: within both soil types, the measured environmental variables explained approximately 32 - 35% of the variation in vegetation. No single measured environmental variable adequately described the observed gradients in vegetation; rather, vegetation gradients showed strong correlations with complex environmental gradients. These complex environmental gradients included nutrient, moisture and soil physical and site variables. These results suggest a simple 'nutrient' hypothesis regarding vegetation patterns in the Central Coast region is inadequate to explain variation in vegetation within soil types