3,190 research outputs found

    Different Approaches to Dual Enrollment: Understanding Program Features and Their Implications

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    Examines program features, challenges, and benefits of secondary-postsecondary partnerships that allow high school students to take college courses for credit, with a career-focused strategy for engaging underperforming students. Includes recommendations

    Non-binary Living in a Binary World: The Unlabeled Experience

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    Both popular media and social science research suggest that gender/sexual identities and roles that have dominated western society are being challenged (Budgeon, 2014). Heteronormative assumptions and the gender binary are rapidly evolving to capture experiences that reflect greater diversity (Diamond, 2005; Nagoshi et al., 2012), including those that extend beyond labels. We surveyed 915 individuals regarding their gender identity, sexual orientation, and numerous psychological measures related to well-being, in order to understand the experience of those who choose to remain unlabeled. The data would suggest that those not ascribing to the gender binary have lower reported satisfaction with life across several axes when compared to cisgender participants. Explaining their ‘unlabeled’ status, participants described their primary identification as human, expressed discomfort with gender-based assumptions and rejected constrictions of the gender binary

    Gravitational waves from binaries on unbound orbits

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    A generalized true anomaly-type parametrization, convenient to describe both bound and open orbits of a two-body system in general relativity is introduced. A complete description of the time evolution of both the radial and of the angular equations of a binary system taking into account the first order post-newtonian (1PN) is given. The gravitational radiation field emitted by the system is computed in the 1PN approximation including higher multipole moments beyond the standard quadrupole term. The gravitational waveforms in the time domain are explicitly given up to the 1PN order for unbound orbits, but the results are also illustrated on binaries on elliptic orbits with special attention given to the effects of eccentricity.Comment: 27 pages, 10 figures, to appear in Phys. Rev.

    Arecibo HI Absorption Measurements of Pulsars and the Electron Density at Intermediate Longitudes in the First Galactic Quadrant

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    We have used the Arecibo telescope to measure the HI absorption spectra of eight pulsars. We show how kinematic distance measurements depend upon the values of the galactic constants R_o and Theta_o, and we select our preferred current values from the literature. We then derive kinematic distances for the low-latitude pulsars in our sample and electron densities along their lines of sight. We combine these measurements with all others in the inner galactic plane visible from Arecibo to study the electron density in this region. The electron density in the interarm range 48 degrees < l < 70 degrees is [0.017 (-0.007,+0.012) (68% c.l.)] cm^(-3). This is 0.75 (-0.22,+0.49) (68% c.l.) of the value calculated by the Cordes & Lazio (2002) galactic electron density model. The model agrees more closely with electron density measurements toward Arecibo pulsars lying closer to the galactic center, at 30 degrees<l<48 degrees. Our analysis leads to the best current estimate of the distance of the relativistic binary pulsar B1913+16: d=(9.0 +/- 3) kpc. We use the high-latitude pulsars to search for small-scale structure in the interstellar hydrogen observed in absorption over multiple epochs. PSR B0301+19 exhibited significant changes in its absorption spectrum over 22 yr, indicating HI structure on a ~500 AU scale.Comment: Accepted by Astrophysical Journal September 200

    Use of cranial characters in taxonomy of the Minnesota wolf (\u3ci\u3eCanis\u3c/i\u3e sp.)

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    Minnesota wolves (Canis sp.) sometimes are reported to have affinity to a small, narrow-skulled eastern form (Canis lupus lycaon Schreber, 1775) and sometimes to a larger, broader western form (Canis lupus nubilus Say, 1823). We found that pre-1950 Minnesota wolf skulls were similar in size to those of wolves from southeastern Ontario and smaller than those of western wolves. However, Minnesota wolf skulls during 1970–1976 showed a shift to the larger, western form. Although Minnesota skull measurements after 1976 were unavailable, rostral ratios from 1969 through 1999 were consistent with hybridization between the smaller eastern wolf and the western form. Our findings help resolve the different taxonomic interpretations of Minnesota skull morphology and are consistent with molecular evidence of recent hybridization or intergradation of the two forms of wolves in Minnesota. Together these data indicate that eastern- and western-type wolves historically mixed and hybridized in Minnesota and continue to do so. Our findings are relevant to a recent government proposal to delist wolves from the endangered species list in Minnesota and surrounding states. On associe les loups (Canis sp.) du Minnesota quelquefois avec une forme de l’est de petite taille et à crâne étroit (Canis lupus lycaon Schreber, 1775) et d’autres fois à une forme de l’ouest (Canis lupus nubilus Say, 1823) plus grande et à crâne plus large. Nous observons que les crânes de loups du Minnesota récoltés avant 1950 sont de taille semblable à ceux de loups du sud-est de l’Ontario et plus petits que ceux des loups de l’ouest. Cependant, les crânes de loups du Minnesota durant la période de 1970–1976 montrent un déplacement de taille vers la forme plus grande de l’ouest. Bien qu’aucune mesure de crânes du Minnesota ne soit disponible après 1976, les rapports des rostres de 1969 jusqu’à la fin de 1999 sont compatibles avec une hybridation entre le loup plus petit de l’est et la forme de l’ouest. Nos données aident à résoudre les différences d’interprétation taxonomique de la morphologie des crânes du Minnesota et concordent avec les preuves moléculaires d’une hybridation récente ou d’une intégration des deux formes de loups du Minnesota. Conjointement, ces données indiquent que les loups des types est et ouest se sont mêlés et hybridés dans le passé au Minnesota et continuent de le faire. Nos résultats sont pertinents compte tenu d’une proposition gouvernementale récente de retirer les loups de la liste des espèces en péril au Minnesota et dans les états adjacents

    Testing post-Newtonian theory with gravitational wave observations

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    The Laser Interferometric Space Antenna (LISA) will observe supermassive black hole binary mergers with amplitude signal-to-noise ratio of several thousands. We investigate the extent to which such observations afford high-precision tests of Einstein's gravity. We show that LISA provides a unique opportunity to probe the non-linear structure of post-Newtonian theory both in the context of general relativity and its alternatives.Comment: 9 pages, 2 figure

    Detection of OH absorption against PSR B1849+00

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    We have searched for OH absorption against seven pulsars using the Arecibo telescope. In both OH mainlines (at 1665 and 1667 MHz), deep and narrow absorption features were detected toward PSR B1849+00. In addition, we have detected several absorption and emission features against B33.6+0.1, a nearby supernova remnant (SNR). The most interesting result of this study is that a pencil-sharp absorption sample against the PSR differs greatly from the large-angle absorption sample observed against the SNR. If both the PSR and the SNR probe the same molecular cloud then this finding has important implications for absorption studies of the molecular medium, as it shows that the statistics of absorbing OH depends on the size of the background source. We also show that the OH absorption against the PSR most likely originates from a small (<30 arcsec) and dense (>10^5 cm^-3) molecular clump.Comment: 12 pages, 8 figures. Accepted for publication in Ap

    "Antiscepticism and Easy Justification" - Ch 5 of Seemings and Epistemic Justification

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    In this chapter I investigate epistemological consequences of the fact that seeming-based justification is elusive, in the sense that the subject can lose this justification simply by reflecting on her seemings. I argue that since seeming-based justification is elusive, the antisceptical bite of phenomenal conservatism is importantly limited. I also contend that since seeming-based justification has this feature, phenomenal conservatism isn’t actually afflicted by easy justification problems

    Model-Independent Test of General Relativity: An Extended post-Einsteinian Framework with Complete Polarization Content

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    We develop a model-independent test of General Relativity that allows for the constraint of the gravitational wave (GW) polarization content with GW detections of binary compact object inspirals. We first consider three modified gravity theories (Brans-Dicke theory, Rosen's theory and Lightman-Lee theory) and calculate the response function of ground-based detectors to gravitational waves in the inspiral phase. This allows us to see how additional polarizations predicted in these theories modify the General Relativistic prediction of the response function. We then consider general power-law modifications to the Hamiltonian and radiation-reaction force and study how these modify the time-domain and Fourier response function when all polarizations are present. From these general arguments and specific modified gravity examples, we infer an improved parameterized post-Einsteinian template family with complete polarization content. This family enhances General Relativity templates through the inclusion of new theory parameters, reducing to the former when these parameters acquire certain values, and recovering modified gravity predictions for other values, including all polarizations. We conclude by discussing detection strategies to constrain these new, polarization theory parameters by constructing certain null channels through the combination of output from multiple detectors.Comment: 20 pages, 1 figure, added erratum correcting some intermediate equation
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