39 research outputs found
NICE : A Computational solution to close the gap from colour perception to colour categorization
The segmentation of visible electromagnetic radiation into chromatic categories by the human visual system has been extensively studied from a perceptual point of view, resulting in several colour appearance models. However, there is currently a void when it comes to relate these results to the physiological mechanisms that are known to shape the pre-cortical and cortical visual pathway. This work intends to begin to fill this void by proposing a new physiologically plausible model of colour categorization based on Neural Isoresponsive Colour Ellipsoids (NICE) in the cone-contrast space defined by the main directions of the visual signals entering the visual cortex. The model was adjusted to fit psychophysical measures that concentrate on the categorical boundaries and are consistent with the ellipsoidal isoresponse surfaces of visual cortical neurons. By revealing the shape of such categorical colour regions, our measures allow for a more precise and parsimonious description, connecting well-known early visual processing mechanisms to the less understood phenomenon of colour categorization. To test the feasibility of our method we applied it to exemplary images and a popular ground-truth chart obtaining labelling results that are better than those of current state-of-the-art algorithms
Effect of Angiogenesis Inhibitor Bevacizumab on Survival in Patients with Cancer: A Meta-Analysis of the Published Literature
Bevacizumab is a recombinant humanized monoclonal antibody against vascular endothelial growth factor which has been used in conjunction with other anti-cancer agents in the treatment of patients with many cancers. It remains controversial whether bevacizumab can prolong survival in cancer patients. This meta-analysis was therefore performed to evaluate effect of bevacizumab on survival in cancer patients. PubMed, EMBASE, and Web of Science databases were searched for English-language studies of randomized controlled trials comparing bevacizumab with control therapy published through February 8, 2012. Progression-free survival, overall survival, and one-year survival rate were analyzed using random- or fixed-effects model. Thirty one assessable randomized controlled trials were identified. A significant improvement in progression-free survival in cancer patients was attributable to bevacizumab compared with control therapy (hazard ratio, 0.72; 95% confidence interval, 0.68 to 0.76; p<0.001). Overall survival was also significantly longer in patients were treated with bevacizumab (hazard ratio, 0.87; 95% confidence interval, 0.83 to 0.91; p<0.001). The significant benefit in one-year survival rate was further seen in cancer patients receiving bevacizumab (odds ratio, 1.30; 95% confidence interval, 1.20 to 1.41; p<0.001). Current evidences showed that bevacizumab prolong progression-free survival and overall survival, and increase one-year survival rate in cancer patients as compared with control therapy
Exploiting the therapeutic potential of the PI3K-AKT-mTOR pathway in enriched populations of gynecologic malignancies
Given the prevalence of phosphatase & tensin homolog mutations in histologic specimens harvested from patients with endometrial cancer, significant interest in systemic treatment with PI3K/Akt/mTOR inhibitors has emerged. Several Phase II trials have been completed studying mTOR inhibitors in advanced/recurrent endometrial cancer. The mTOR pathway also appears to be important in some cervical cancers. Finally, because clear cell carcinoma of the ovary and renal cell carcinoma have a shared histology, the potential for activity of mTOR inhibitors in clear cell cancer of the ovary is implicit. This article reviews the results of Phase II clinical trials of PI3K/Akt/mTOR pathway inhibitors in patients with endometrial cancer, and discusses the potential therapeutic landscape of mTOR inhibition in enriched populations in gynecologic cancers
Understanding the retinal basis of vision across species
The vertebrate retina first evolved some 500 million years ago in ancestral marine chordates. Since then, the eyes of different species have been tuned to best support their unique visuoecological lifestyles. Visual specializations in eye designs, large-scale inhomogeneities across the retinal surface and local circuit motifs mean that all species' retinas are unique. Computational theories, such as the efficient coding hypothesis, have come a long way towards an explanation of the basic features of retinal organization and function; however, they cannot explain the full extent of retinal diversity within and across species. To build a truly general understanding of vertebrate vision and the retina's computational purpose, it is therefore important to more quantitatively relate different species' retinal functions to their specific natural environments and behavioural requirements. Ultimately, the goal of such efforts should be to build up to a more general theory of vision
Biometric monitor with electronics disposed on or in a neck collar
A highly portable biometric monitor is disclosed. At least one remote sensor member (12, 12') includes one or more biometric sensors (20, 22, 24, 25) configured for operative coupling with a patient. A neck collar (14, 114, 214, 314, 414) includes electronics (36, 40, 42, 44, 46, 48) for operating the at least one remote sensor member. The at least one remote sensor member is separate from and not disposed on the neck collar. Optionally, the collar also includes one or more biometric sensors (53). A communication link (18) operatively connects the remote sensor member and the electronics of the neck collar.; A motion sensor (26) and position sensor (28) may be disposed with the one or more biometric sensors to sense movement and position, and the electronics (36, 40, 42, 44, 46, 48) configured to account for error in a signal produced by the one or more biometric sensors due to movement sensed by the motion sensor or position sensed by the position sensor. The electronics (36, 40, 42, 44, 46, 48) may log patient activity and body position
Bradykinesia models
Bradykinesia is the cardinal symptom of Parkinson’s disease (PD). It is related to an abnormal
slowness of movement. The causes of PD bradykinesia are not known largely, because there are
multiple brain areas and pathways involved from the neuronal degeneration site (dopamine
neurons in substantia nigra pars compacta (SNc) and ventral tegmental area (VTA)) to the muscles.
Bradykinesia models are mathematical and computational constructs attempting to uncover how
information is processed in the affected brain areas and what are the biophysical mechanisms
giving rise to the observed slowness of movement in PD bradykinesia