470 research outputs found

    Racial Differences in Surgeons and Hospitals for Endometrial Cancer Treatment

    Get PDF
    PURPOSE: To determine whether (1) black and white women with endometrial cancer were treated by different surgical specialties and in different types of hospitals and (2) differences in specialty and hospital type contributed to racial differences in survival. METHODS: Retrospective cohort study of 12,307 women aged 65 years and older who underwent surgical treatment of endometrial cancer between 1991 and 1999 in the 11 Surveillance Epidemiology and End Results registries. RESULTS: Black women were more likely to have a gynecologic oncologist to perform their surgery and to be treated at hospitals that were higher volume, larger, teaching, National Cancer Institute centers, urban, and where a greater proportion of the surgeries were performed by a gynecologic oncologist. In unadjusted models, black women were over twice as likely as white women who died because of cancer (hazards ratio [HR]: 2.33), but nearly all of the initial racial difference in survival was explained by differences in cancer stage, and grade as well as age and comorbidities at presentation (adjusted HR: 1.10). Surgical specialty was not associated with survival and, of the hospital characteristics studied, only surgical volume was associated with survival (P \u3c 0.005). Adjusting for hospital characteristics did not change the racial difference in survival (HR: 1.10). Adjustment for the specific hospital where the woman was treated eliminated the association between race and surgeon specialty and slightly widened the residual racial difference in survival (HR: 1.23 vs. 1.10). CONCLUSIONS: In contrast to several studies suggesting that blacks with breast cancer, colon cancer, or cardiovascular disease are treated in hospitals with lower quality indicators, black women diagnosed with endometrial cancer in Surveillance Epidemiology and End Results regions between 1991 and 1999 were more likely to be treated by physicians with advanced training and in high volume, large, urban, teaching hospitals. However, except for a modest association with hospital surgical volume, these provider and hospital characteristics were largely unrelated to survival for women with endometrial cancer. The great majority of the difference in survival was explained by differences in tumor and clinical characteristics at presentation

    Labelling, Deviance and Media

    Get PDF
    Labelling theory is a perspective that emerged as a distinctive approach to criminology during the 1960s, and was a major seedbed of the radical and critical perspectives that became prominent in the 1970s. It represented the highpoint of an epistemological shift within the social sciences away from positivism – which had dominated criminological enquiry since the late-1800s – and toward an altogether more relativistic stance on the categories and concepts of crime and control. It inspired a huge amount of work throughout the 1960s and 1970s, and still resonates powerfully today. This short chapter maps out some of the ways in which labelling, deviance, media and justice interact at the levels of definition and process. It presents an overview and analysis of key mediatised labelling processes, such as the highly influential concept of moral panics. It discusses how the interconnections between labelling, crime and criminal justice are changing in a context of technological development, cultural change and media proliferation. The conclusion offers an assessment and evaluation of labelling theory’s long-term impact on criminology

    The child care worker as a role model

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44268/1/10566_2005_Article_BF01554452.pd

    Gradient estimation in dendritic reinforcement learning

    Get PDF
    We study synaptic plasticity in a complex neuronal cell model where NMDA-spikes can arise in certain dendritic zones. In the context of reinforcement learning, two kinds of plasticity rules are derived, zone reinforcement (ZR) and cell reinforcement (CR), which both optimize the expected reward by stochastic gradient ascent. For ZR, the synaptic plasticity response to the external reward signal is modulated exclusively by quantities which are local to the NMDA-spike initiation zone in which the synapse is situated. CR, in addition, uses nonlocal feedback from the soma of the cell, provided by mechanisms such as the backpropagating action potential. Simulation results show that, compared to ZR, the use of nonlocal feedback in CR can drastically enhance learning performance. We suggest that the availability of nonlocal feedback for learning is a key advantage of complex neurons over networks of simple point neurons, which have previously been found to be largely equivalent with regard to computational capability

    A distance of a point from a line

    Get PDF
    U ovom članku razmatra se metoda računanja udaljenosti točke od eksplicitno, parametarski, te polarno zadane krivulje. U literaturi za ovaj problem postoji eksplicitno rješenje za slučaj afine funkcije, te za još neke specijalne slučajeve.This article considers the method for calculating the distance of a point to the curve given explicitly, in parameter and polar form. In literature, there exists an explicit solution to this problem for the case of affine fuctions as well as for some other special cases

    Experience-based VAS values for EQ-5D-3L health states in a national general population health survey in China

    Get PDF
    Purpose: To investigate the feasibility of deriving experience-based visual analogue scale (VAS) values for EQ-5D-3L health states using national general population health survey data in China. Methods: The EQ-5D-3L was included in the National Health Services Survey (n = 120,709, aged 15–103 years) to measure health-related quality of life. The respondents reported their current health status on a VAS and completed the EQ-5D-3L questionnaire, enabling modelling of the association between the experience-based VAS values and self-reported problems on EQ-5D dimensions and severity levels. Results: VAS values were generally negatively associated with problems reported on the EQ-5D dimensions, and the anxiety/depression dimension had the greatest impact on VAS values. A previously obtained value for dead allowed the values for all 243 EQ-5D-3L health states to be transformed to the 0–1 scale (0 = dead, 1 = full health). Conclusions: This study presents the feasibility of deriving an experience-based VAS values for EQ-5D-3L health states in China. The analysis of these VAS data raises more fundamental issues concerning the universal nature of the classification system and the extent to which Chinese respondents utilise the same concepts of health as defined by this classification system

    Activation of endogenous p53 by combined p19Arf gene transfer and nutlin-3 drug treatment modalities in the murine cell lines B16 and C6

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Reactivation of p53 by either gene transfer or pharmacologic approaches may compensate for loss of p19Arf or excess mdm2 expression, common events in melanoma and glioma. In our previous work, we constructed the pCLPG retroviral vector where transgene expression is controlled by p53 through a p53-responsive promoter. The use of this vector to introduce p19Arf into tumor cells that harbor p53wt should yield viral expression of p19Arf which, in turn, would activate the endogenous p53 and result in enhanced vector expression and tumor suppression. Since nutlin-3 can activate p53 by blocking its interaction with mdm2, we explored the possibility that the combination of p19Arf gene transfer and nutlin-3 drug treatment may provide an additive benefit in stimulating p53 function.</p> <p>Methods</p> <p>B16 (mouse melanoma) and C6 (rat glioma) cell lines, which harbor p53wt, were transduced with pCLPGp19 and these were additionally treated with nutlin-3 or the DNA damaging agent, doxorubicin. Viral expression was confirmed by Western, Northern and immunofluorescence assays. p53 function was assessed by reporter gene activity provided by a p53-responsive construct. Alterations in proliferation and viability were measured by colony formation, growth curve, cell cycle and MTT assays. In an animal model, B16 cells were treated with the pCLPGp19 virus and/or drugs before subcutaneous injection in C57BL/6 mice, observation of tumor progression and histopathologic analyses.</p> <p>Results</p> <p>Here we show that the functional activation of endogenous p53wt in B16 was particularly challenging, but accomplished when combined gene transfer and drug treatments were applied, resulting in increased transactivation by p53, marked cell cycle alteration and reduced viability in culture. In an animal model, B16 cells treated with both p19Arf and nutlin-3 yielded increased necrosis and decreased BrdU marking. In comparison, C6 cells were quite susceptible to either treatment, yet p53 was further activated by the combination of p19Arf and nutlin-3.</p> <p>Conclusions</p> <p>To the best of our knowledge, this is the first study to apply both p19Arf and nutlin-3 for the stimulation of p53 activity. These results support the notion that a p53 responsive vector may prove to be an interesting gene transfer tool, especially when combined with p53-activating agents, for the treatment of tumors that retain wild-type p53.</p

    Models of Neocortical Layer 5b Pyramidal Cells Capturing a Wide Range of Dendritic and Perisomatic Active Properties

    Get PDF
    The thick-tufted layer 5b pyramidal cell extends its dendritic tree to all six layers of the mammalian neocortex and serves as a major building block for the cortical column. L5b pyramidal cells have been the subject of extensive experimental and modeling studies, yet conductance-based models of these cells that faithfully reproduce both their perisomatic Na+-spiking behavior as well as key dendritic active properties, including Ca2+ spikes and back-propagating action potentials, are still lacking. Based on a large body of experimental recordings from both the soma and dendrites of L5b pyramidal cells in adult rats, we characterized key features of the somatic and dendritic firing and quantified their statistics. We used these features to constrain the density of a set of ion channels over the soma and dendritic surface via multi-objective optimization with an evolutionary algorithm, thus generating a set of detailed conductance-based models that faithfully replicate the back-propagating action potential activated Ca2+ spike firing and the perisomatic firing response to current steps, as well as the experimental variability of the properties. Furthermore, we show a useful way to analyze model parameters with our sets of models, which enabled us to identify some of the mechanisms responsible for the dynamic properties of L5b pyramidal cells as well as mechanisms that are sensitive to morphological changes. This automated framework can be used to develop a database of faithful models for other neuron types. The models we present provide several experimentally-testable predictions and can serve as a powerful tool for theoretical investigations of the contribution of single-cell dynamics to network activity and its computational capabilities
    corecore