182 research outputs found
Sometimes You Cannot Have It All: Party Switching and Affiliation Motivations as Substitutes
Existing research on when legislators switch parties reports inconsistent results about motivations for switching (e.g., office, ideology, and votes). I treat the motivations for party switching as substitutes and argue that many of the inconsistencies that persist can be explained by modelling the interactive effects between these motivations. For example, scholars differ in terms of whether they find that electoral considerations are an important determinant of party switching. The conflicting findings on the independent effects of electoral considerations are explained here by demonstrating that these effects are conditional on the level of office benefits a legislators enjoys, as well as the ideological distance between the legislator and party. More generally, the empirical analysis provides strong support for the substitution effect hypothesis. Thus, modelling interactive effects increases our understanding of party switching
A comprehensive assessment of breast and cervical cancer control infrastructure in Zambia
Introduction: By 2030 cancer will kill one million Africans each year. Women will bear the heaviest burden, as cancers of the breast and cervix are the most common malignancies and causes of cancer-related death in the African region. National-level data that map the status of women's cancer control services are needed to inform strategies for implementing platforms for the early detection and treatment of these “priority” cancers. Methods: Using mixed-methods, we assessed available services for breast and cervical cancer detection and treatment at all provincial hospitals, the national referral hospital, and the national cancer treatment center in Zambia. Results: A system for cervical cancer prevention using visual inspection with acetic acid (VIA) and ablation/excision of precancerous lesions has been established at the provincial level. The potential for mammography, clinical breast examination, diagnostic ultrasound and biopsy exist at the provincial level, albeit on a much smaller scale. Breast wedge resections and mastectomy can be performed in provinces where general surgeons are located; however, breast conserving and reconstructive surgery are not available. Invasive cancers are generally referred to University Teaching Hospital in Lusaka, where services for radiation, chemotherapy and hormonal therapy are available but overburdened. Pathology services nationwide are woefully inadequate. Discussion: The assessment revealed a critical need for centrally coordinated, but decentralized, public service platforms for women's cancer control. Efforts are underway, through multiple stakeholders, to implement recommendations related to training healthcare workers who can provide advanced diagnostic and therapeutic services, improving pathology services, and innovative financing for these initiatives
How Haptic Size Sensations Improve Distance Perception
Determining distances to objects is one of the most ubiquitous perceptual tasks in everyday life. Nevertheless, it is challenging because the information from a single image confounds object size and distance. Though our brains frequently judge distances accurately, the underlying computations employed by the brain are not well understood. Our work illuminates these computions by formulating a family of probabilistic models that encompass a variety of distinct hypotheses about distance and size perception. We compare these models' predictions to a set of human distance judgments in an interception experiment and use Bayesian analysis tools to quantitatively select the best hypothesis on the basis of its explanatory power and robustness over experimental data. The central question is: whether, and how, human distance perception incorporates size cues to improve accuracy. Our conclusions are: 1) humans incorporate haptic object size sensations for distance perception, 2) the incorporation of haptic sensations is suboptimal given their reliability, 3) humans use environmentally accurate size and distance priors, 4) distance judgments are produced by perceptual “posterior sampling”. In addition, we compared our model's estimated sensory and motor noise parameters with previously reported measurements in the perceptual literature and found good correspondence between them. Taken together, these results represent a major step forward in establishing the computational underpinnings of human distance perception and the role of size information.National Institutes of Health (U.S.) (NIH grant R01EY015261)University of Minnesota (UMN Graduate School Fellowship)National Science Foundation (U.S.) (Graduate Research Fellowship)University of Minnesota (UMN Doctoral Dissertation Fellowship)National Institutes of Health (U.S.) (NIH NRSA grant F32EY019228-02)Ruth L. Kirschstein National Research Service Awar
Availability of palliative care services in Zambia: A nationwide provincial and tertiary hospital survey
creasingly
need palliative care. While efforts are underway to grow Zambia’s palliative care system, the most
recent situational analysis of palliative care in Zambia, conducted in 2008, revealed substantial gaps in availability.
Methods: To provide an updated appraisal of breast and cervical cancer services in Zambia, including palliative
care, we conducted a nationwide provincial and tertiary hospital survey. All 9 provincial hospitals and the
University Teaching Hospital and Cancer Diseases Hospital in Lusaka Province participated (N=11). The survey
was conducted between August 2014 and January 2015 and administered in-person at each facility. Data regarding
the availability of inpatient, outpatient, and community-based palliative care services, palliative medications,
and psychosocial supports was obtained at each facility. The reported results are descriptive in nature.
Results: Although the need for palliative care services was recognized, many facilities (64%) lack palliative care
policies and only 18% offer palliative care in a coordinated program. The majority of services are only available
to inpatients and rarely include community-based programs. While all facilities had adequate supplies of acetaminophen,
82% reported unavailability of codeine and 45% reported no access to oral morphine.
Conclusions: This assessment confirms the dearth of palliative care services across Zambia. Less than half of its
provincial hospitals offer community- or home-based services and only 55% offer opioid analgesics. Immediate
and substantial improvements in policy, drug procurement and distribution, and service expansion are needed to
ensure high-quality palliative care is available throughout Zambia
A comparison of blindpulling and blindwalking as measures of perceived absolute distance
Taking It to the Extreme:The Effect of Coalition Cabinets on Foreign Policy
Institutional constraints have been offered by some scholars as an explanation for why multiparty coalitions should be more peaceful than single-party cabinets. Yet others see the same institutional setting as a prescription for more aggressive behavior. Recent research has investigated these conflicting expectations, but with mixed results. We examine the theoretical bases for these alternative expectations about the effects of coalition politics on foreign policy. We find that previous research is limited theoretically by confounding institutional effects with policy positions, and empirically by analyzing only international conflict data. We address these limitations by examining cases of foreign policy behavior using the World Event/Interaction Survey (WEIS) dataset. Consistent with our observation that institutional constraints have been confounded with policy positions, we find that coalitions are neither more aggressive nor more peaceful, but do engage in more extreme foreign policy behaviors. These findings are discussed with regard to various perspectives on the role of institutions in shaping foreign policy behavior.</p
The Origin of Glucocorticoid Hormone Oscillations
Characterization of a peripheral hormonal system identifies the origin and mechanisms of regulation of glucocorticoid hormone oscillations in rats
Auditory spatial representations of the world are compressed in blind humans
Compared to sighted listeners, blind listeners often display enhanced auditory spatial abilities such as localization in azimuth. However, less is known about whether blind humans can accurately judge distance in extrapersonal space using auditory cues alone. Using virtualization techniques, we show that auditory spatial representations of the world beyond the peripersonal space of blind listeners are compressed compared to those for normally sighted controls. Blind participants overestimated the distance to nearby sources, and underestimated the distance to remote sound sources, in both reverberant and anechoic environments, and for speech, music and noise signals. Functions relating judged and actual virtual distance were well fitted by compressive power functions, indicating that the absence of visual information regarding the distance of sound sources may prevent accurate calibration of the distance information provided by auditory signals
Sensory substitution information informs locomotor adjustments when walking through apertures
The study assessed the ability of the central nervous system (CNS) to use echoic information from sensory substitution devices (SSDs) to rotate the shoulders and safely pass through apertures of different width. Ten visually normal participants performed this task with full vision, or blindfolded using an SSD to obtain information regarding the width of an aperture created by two parallel panels. Two SSDs were tested. Participants passed through apertures of +0%, +18%, +35%, and +70% of measured body width. Kinematic indices recorded movement time, shoulder rotation, average walking velocity across the trial, peak walking velocities before crossing, after crossing and throughout a whole trial. Analyses showed participants used SSD information to regulate shoulder rotation, with greater rotation associated with narrower apertures. Rotations made using an SSD were greater compared to vision, movement times were longer, average walking velocity lower and peak velocities before crossing, after crossing and throughout the whole trial were smaller, suggesting greater caution. Collisions sometimes occurred using an SSD but not using vision, indicating that substituted information did not always result in accurate shoulder rotation judgements. No differences were found between the two SSDs. The data suggest that spatial information, provided by sensory substitution, allows the relative position of aperture panels to be internally represented, enabling the CNS to modify shoulder rotation according to aperture width. Increased buffer space indicated by greater rotations (up to approximately 35% for apertures of +18% of body width), suggests that spatial representations are not as accurate as offered by full vision
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