2,084 research outputs found

    The Effectiveness of California Assembly Bill 2109: Personal Belief Exemptions for Kindergarten Immunizations

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    The numbers of vaccine preventable diseases (VPDs) in the United States has declined with the development, administration, and effectiveness of vaccines during the 1970s and 1980s. As the eminent threat of VPDs to the public began to wane, parents started questioning the safety and necessity of vaccines. When parents were given the option of selecting personal belief exemption (PBE) waivers for state mandated immunizations for their incoming kindergarten children, an increase in PBEs and the number of VPD outbreaks began to occur. To counter the growing trend of PBEs, and to prevent outbreaks of VPDs in school settings and communities, California Assembly Bill2109 (AB 2109, 2012) was created to help educate parents about vaccine safety and VPDs. As of January 2014, California Assembly Bill2109 (AB 2109, 2012) mandated that parents seeking PBEs for state mandated immunizations for students entering kindergarten were required to receive education about vaccine safety and risks along with education regarding VPDs by a health care professional (AB 2109, 2012). The purpose of this study was to examine the effectiveness of AB 21 09 by examining data from the top ten most populous counties in California. Data was collected for the 2013-2014, 2014-2015, and 2015- 2016 school years to determine if AB 2109 directly impacted the number of PBEs for incoming kindergartners. This project determined that AB 2109 was significant in decreasing the number 3 of PBEs from the 2013-2014,2014-2015, and 2015-2016 school years by -23.4% in the ten most populous counties in California. Further research beyond this project is necessary to evaluate the continued impact of AB 2109 on PBEs and in decreasing the number of VPD outbreaks throughout California

    The Non-Monotonic Dependence of Supernova and Remnant Formation on Progenitor Rotation

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    Traditional models of core collapse suggest the issue of successful versus failed supernova explosions and neutron star versus black hole formation depends monotonically on the mass (and metallicity) of the progenitor star. Here we argue that the issue of success or failure of the explosion or other possible outcomes may depend non--monotonically on the rotation of the progenitor star even at fixed progenitor mass and composition. We have computed "shellular" models of core collapse for a star of 15 M_solar with initial central angular velocity, Omega_0, in the range 0.1 -- 8 rad/s until a few hundred ms after bounce to explore qualitative trends. The non--monotonic behavior will be manifested in the rotation of the proto--neutron star and hence in the strength of the associated magnetic field that will be generated by shear in that rotating environment. We estimate that our maximally rotating and shearing models generate toroidal fields approaching or exceeding 10^17G, strengths nearing dynamical significance.Comment: 20 pages, 6 figures, accepted for publication in The Astrophysical Journal. Few typos are correcte

    Extreme offspring ornamentation in American coots is favored by selection within families, not benefits to conspecific brood parasites

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    Offspring ornamentation typically occurs in taxa with parental care, suggesting that selection arising from social interactions between parents and offspring may underlie signal evolution. American coot babies are among the most ornamented offspring found in nature, sporting vividly orange-red natal plumage, a bright red beak, and other red parts around the face and pate. Previous plumage manipulation experiments showed that ornamented plumage is favored by strong parental choice for chicks with more extreme ornamentation but left unresolved the question as to why parents show the preference. Here we explore natural patterns of variation in coot chick plumage color, both within and between families, to understand the context of parental preference and to determine whose fitness interests are served by the ornamentation. Conspecific brood parasitism is common in coots and brood parasitic chicks could manipulate hosts by tapping into parental choice for ornamented chicks. However, counter to expectation, parasitic chicks were duller (less red) than nonparasitic chicks. This pattern is explained by color variation within families: Chick coloration increases with position in the egg-laying order, but parasitic eggs are usually the first eggs a female lays. Maternal effects influence chick coloration, but coot females do not use this mechanism to benefit the chicks they lay as parasites. However, within families, chick coloration predicts whether chicks become “favorites” when parents begin control over food distribution, implicating a role for the chick ornamentation in the parental life-history strategy, perhaps as a reliable signal of a chick’s size or age. (Includes Supporting information.

    Magnetic Fields in Core Collapse Supernovae: Possibilities and Gaps

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    Spectropolarimetry of core collapse supernovae has shown that they are asymmetric and often, but not universally, bi-polar. The Type IIb SN1993J and similar events showed large scatter in the Stokes parameter plane. Observational programs clearly have much more to teach us about the complexity of asymmetric supernovae and the physics involved in the asymmetry. Jet-induced supernova models give a typical jet/torus structure that is reminiscent of some objects like the Crab nebula, SN1987A and perhaps Cas A. Jets, in turn, may arise from the intrinsic rotation and magnetic fields that are expected to accompany core collapse. We summarize the potential importance of the magneto-rotational instability for the core collapse problem and sketch some of the effects that large magnetic fields, ~10^{15} G, may have on the physics of the supernova explosion. Open issues in the problem of multi-dimensional magnetic core collapse are summarized and a critique is given of some recent MHD collapse calculations.Comment: 20 pages, 2 figures, to appear in the proceedings of the INT workshop "Open Issues in Understanding Core Collapse Supernovae," Seattle, 2004, ed. T. Mezzacappa (World Scientific

    Extreme offspring ornamentation in American coots is favored by selection within families, not benefits to conspecific brood parasites

    Get PDF
    Offspring ornamentation typically occurs in taxa with parental care, suggesting that selection arising from social interactions between parents and offspring may underlie signal evolution. American coot babies are among the most ornamented offspring found in nature, sporting vividly orange-red natal plumage, a bright red beak, and other red parts around the face and pate. Previous plumage manipulation experiments showed that ornamented plumage is favored by strong parental choice for chicks with more extreme ornamentation but left unresolved the question as to why parents show the preference. Here we explore natural patterns of variation in coot chick plumage color, both within and between families, to understand the context of parental preference and to determine whose fitness interests are served by the ornamentation. Conspecific brood parasitism is common in coots and brood parasitic chicks could manipulate hosts by tapping into parental choice for ornamented chicks. However, counter to expectation, parasitic chicks were duller (less red) than nonparasitic chicks. This pattern is explained by color variation within families: Chick coloration increases with position in the egg-laying order, but parasitic eggs are usually the first eggs a female lays. Maternal effects influence chick coloration, but coot females do not use this mechanism to benefit the chicks they lay as parasites. However, within families, chick coloration predicts whether chicks become “favorites” when parents begin control over food distribution, implicating a role for the chick ornamentation in the parental life-history strategy, perhaps as a reliable signal of a chick’s size or age. (Includes Supporting information.

    MHD Simulations of Core Collapse Supernovae with Cosmos++

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    We performed 2D, axisymmetric, MHD simulations with Cosmos++ in order to examine the growth of the magnetorotational instability (MRI) in core--collapse supernovae. We have initialized a non--rotating 15 solar mass progenitor, infused with differential rotation and poloidal magnetic fields. The collapse of the iron core is simulated with the Shen EOS, and the parametric Ye and entropy evolution. The wavelength of the unstable mode in the post--collapse environment is expected to be only ~ 200 m. In order to achieve the fine spatial resolution requirement, we employed remapping technique after the iron core has collapsed and bounced. The MRI unstable region appears near the equator and angular momentum and entropy are transported outward. Higher resolution remap run display more vigorous overturns and stronger transport of angular momentum and entropy. Our results are in agreement with the earlier work by Akiyama et al. (2003) and Obergaulinger et al. (2009).Comment: 3 pages, 2 figures. To appear in the proceedings of the "Deciphering the Ancient Universe with Gamma-Ray Bursts", April 2010, Kyoto, Japan, eds. N. Kawai and S. Nagataki (AIP

    Tax Reform in Japan: The Case of Personal Taxes

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    In this paper, we conduct a theoretical analysis of personal taxes (defined to include consumption and income taxes), describe and evaluate the past and present structure of personal taxes in Japan, and based on our findings, make a number of policy recommendations about how to reform personal taxes in Japan. We find that the structure of Japan's current consumption and income taxes is problematic from the viewpoints of both efficiency and equity and propose a reform package that improves both the efficiency and equity of Japan's personal taxes and, at the same time, achieves fiscal reconstruction.

    The Role of Nestling Acoustic Experience in Song Discrimination in a Sparrow

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    Oscine songbirds are an ideal system for investigating how early experience affects vocal behavior. Young songbirds face a challenging task: how to recognize and selectively learn only their own species’ song, often during a time-limited window. Because birds are capable of hearing birdsong very early in life, early exposure to song could plausibly affect recognition of appropriate models; however, this idea conflicts with the traditional view that song learning occurs only after a bird leaves the nest. Thus, it remains unknown whether natural variation in acoustic exposure prior to song learning affects the template for recognition. In a population where sister species, golden-crowned and white-crowned sparrows, breed syntopically, we found that nestlings discriminate between heterospecific and conspecific song playbacks prior to the onset of song memorization. We then asked whether natural exposure to more frequent or louder heterospecific song explained any variation in golden-crowned nestling response to heterospecific song playbacks. We characterized the amount of each species’ song audible in golden-crowned sparrow nests and showed that even in a relatively small area, the ratio of heterospecific to conspecific song exposure varies from 0 to 20%. However, although many songbirds hear and respond to acoustic signals before fledging, golden-crowned sparrow nestlings that heard different amounts of heterospecific song did not behave differently in response to heterospecific playbacks. This study provides the first evidence that song discrimination at the onset of song learning is robust to the presence of closely related heterospecifics in nature, which may be an important adaptation in sympatry between potentially interbreeding taxa
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