833 research outputs found
Knowledge Level and Degree of Utilization of the Self-Study Materials Center, Booth Library
No abstract provided by author
Knowledge Level and Degree of Utilization of the Self-Study Materials Center, Booth Library
No abstract provided by author
Observations on the Morphology and Life History of Oswaldocruzia sp. in Frogs
A series of experiments were instituted in order to clarify the life history of Oswaldocruzia sp., a nematode of frogs. Suitable hosts were collected and examined for the nematode. Artificial infection of laboratory reared frog tadpoles and young frogs by use of incubated juvenile stages of the parasite was undertaken with negative results. Several reasons are suggested to explain failure of infection attempts. The likelihood that juvenile Oswaldocruzia used experimentally were not infective stages of the parasite is suggested. Morphological characters of the worms support this idea. The possibility that tadpoles and young frogs are refractory to infection, and involvement of an intermediate is discussed. Morphology of adult and juvenile Oswaldocruzia is outlined, and comparisons to recorded descriptions are made
The Course of Columbiform Plasmodium Relictum Infections in Canaries
Canaries were inoculated with a strain of Plasmodium relictum isolated from a mourning dove and maintained by blood passage through pigeons. Parasitemias reached a peak on the fourth day following inoculation in all but two birds, dropped sharply thereafter and remained at low levels through the tenth day of infection. An asexual cycle of twenty to twenty-four hours was observed, with matinal and synchronous sporulation. Gametocyte numbers were low throughout the infections and eleven merozoites, on the average, were produced per mature schizont. Signs of pathogenicity were not observed and all infected birds survived the active phase of infection. The host-specificity of the parasite is discussed
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[Least Angle Regression]: Discussion
Algorithms for simultaneous shrinkage and selection in regression and classification provide attractive solutions to knotty old statistical challenges. Nevertheless, as far as we can tell, Tibshirani's Lasso algorithm has had little impact on statistical practice. Two particular reasons for this may be the relative inefficiency of the original Lasso algorithm and the relative complexity of more recent Lasso algorithms [e.g., Osborne, Presnell and Turlach (2000)]. Efron, Hastie, Johnstone and Tibshirani have provided an efficient, simple algorithm for the Lasso as well as algorithms for stagewise regression and the new least angle regression. As such this paper is an important contribution to statistical computing
Fairness Beyond Disparate Treatment & Disparate Impact: Learning Classification without Disparate Mistreatment
Automated data-driven decision making systems are increasingly being used to
assist, or even replace humans in many settings. These systems function by
learning from historical decisions, often taken by humans. In order to maximize
the utility of these systems (or, classifiers), their training involves
minimizing the errors (or, misclassifications) over the given historical data.
However, it is quite possible that the optimally trained classifier makes
decisions for people belonging to different social groups with different
misclassification rates (e.g., misclassification rates for females are higher
than for males), thereby placing these groups at an unfair disadvantage. To
account for and avoid such unfairness, in this paper, we introduce a new notion
of unfairness, disparate mistreatment, which is defined in terms of
misclassification rates. We then propose intuitive measures of disparate
mistreatment for decision boundary-based classifiers, which can be easily
incorporated into their formulation as convex-concave constraints. Experiments
on synthetic as well as real world datasets show that our methodology is
effective at avoiding disparate mistreatment, often at a small cost in terms of
accuracy.Comment: To appear in Proceedings of the 26th International World Wide Web
Conference (WWW), 2017. Code available at:
https://github.com/mbilalzafar/fair-classificatio
HST Observations of the Host Galaxies of BL Lacertae Objects
Six BL Lac objects from the complete 1 Jy radio-selected sample of 34 objects
were observed in Cycle 5 with the HST WFPC2 camera to an equivalent limiting
flux of mu_I~26 mag/arcsec^2. Here we report results for the second half of
this sample, as well as new results for the first three objects, discussed
previously by Falomo et al. (1997). In addition, we have analyzed in the same
way HST images of three X-ray-selected BL Lacs observed by Jannuzi et al.
(1997). The ensemble of 9 BL Lac objects spans the redshift range from z=0.19
to ~1. Host galaxies are clearly detected in seven cases, while the other two,
at z~0.258 (redshift highly uncertain) and z=0.997, are not resolved. The HST
images constitute a homogeneous data set with unprecedented morphological
information between a few tenths of an arcsecond and several arcseconds from
the nucleus, allowing us in 6 of the 7 detected host galaxies to rule out
definitively a pure disk light profile. The host galaxies are luminous
ellipticals with an average absolute magnitude of M_I~-24.6 mag (with
dispersion 0.7 mag), more than a magnitude brighter than L* and comparable to
brightest cluster galaxies. The morphologies are generally smooth and have
small ellipticities (epsilon<0.2). Given such roundness, there is no obvious
alignment with the more linear radio structures. In the six cases for which we
have HST WFPC2 images in two filters, the derived color profiles show no strong
spatial gradients and are as expected for K-corrected passively evolving
elliptical galaxies. The host galaxies of the radio-selected and X-ray-selected
BL Lacs for this very limited sample are comparable in both morphology and
luminosity.Comment: 23 pages, including 6 postscript figures and 3 tables (embedded).
Latex requires aaspp4.sty and psfig.sty (not included). Accepted for
publication in the Astrophysical Journa
Stigma and Social Power: Expecting to Interact with an Obese Person Activates Power in the Self-concept
People's sense of power is often a more crucial determinant of their behavior than their actual level of power. In this paper, we suggest that individuals may perceive themselves as more powerful when anticipating interaction with a member of a stigmatized out-group than with a member of a nonstigmatized group. Normal weight participants (N = 77) expected to have an interaction with a target randomly identified as obese or thin. Participants were quicker to endorse words describing themselves in terms of traits associated with power when the target was obese than thin. They were also likely to expect greater interpersonal power, to endorse more negative attitudes towards obese people and to form more negative impressions, if the target was obese rather than thin. These findings suggest that a perception of empowerment is spontaneously activated prior to interaction with an obese person.http://www.informaworld.com/smpp/content~db=all~content=a907123882~frm=titlelinkSCOPUS: ar.jinfo:eu-repo/semantics/publishe
Surgical treatment of uterine prolapse in women with bladder exstrophy: report of two cases with modified Prolift™ procedure
The incidence of pelvic organ prolapse is 18% in women with bladder exstrophy. A vaginal technique to correct the prolapse may be preferable in these women with multiple abdominal operations in their histories. We have performed a modified Prolift™ procedure for the repair of severe uterine prolapse in two young women. A review of the literature is presented
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