3,980 research outputs found
A Study of Willingness to Participate in the Development of a Global Human Community
The need for the development of a global human community has been outlined in recent literature. This study examined the willingness of individuals to endorse and act upon values embodied in a global community. A sample of U.S. adults was asked to indicate commitment to values embodied in the United Nations’ Declaration of Human Rights and Franklin D. Roosevelt’s Four Freedoms, through a formulated message. Participants were also asked of actions they can take to support these values, barriers to such action, and related questions. Results were looked at through different demographic and attitudinal factors. Over half of all participants, regardless of demographic group, were interested in making the commitment encapsulated in our message. There is a strong need to better understand and link actions to the development of a global human community. Better ways to connect people with others who can better support their actions are needed
Cancer Stem Cells in Head and Neck Squamous Cell Carcinoma
Accumulating evidence suggests that self-renewal and differentiation capabilities reside only in a subpopulation of tumor cells, termed cancer stem cells (CSCs), whereas the remaining tumor cell population lacks the ability to initiate tumor development or support continued tumor growth. In head and neck squamous cell carcinoma (HNSCC), as with other malignancies, cancer stem cells have been increasingly shown to have an integral role in tumor initiation, disease progression, metastasis and treatment resistance. In this paper we summarize the current knowledge of the role of CSCs in HNSCC and discuss the therapeutic implications and future directions of this field
On the role of the corpus callosum in interhemispheric functional connectivity in humans
Resting state functional connectivity is defined in terms of temporal correlations between physiologic signals, most commonly studied using functional magnetic resonance imaging. Major features of functional connectivity correspond to structural (axonal) connectivity. However, this relation is not one-to-one. Interhemispheric functional connectivity in relation to the corpus callosum presents a case in point. Specifically, several reports have documented nearly intact interhemispheric functional connectivity in individuals in whom the corpus callosum (the major commissure between the hemispheres) never develops. To investigate this question, we assessed functional connectivity before and after surgical section of the corpus callosum in 22 patients with medically refractory epilepsy. Section of the corpus callosum markedly reduced interhemispheric functional connectivity. This effect was more profound in multimodal associative areas in the frontal and parietal lobe than primary regions of sensorimotor and visual function. Moreover, no evidence of recovery was observed in a limited sample in which multiyear, longitudinal follow-up was obtained. Comparison of partial vs. complete callosotomy revealed several effects implying the existence of polysynaptic functional connectivity between remote brain regions. Thus, our results demonstrate that callosal as well as extracallosal anatomical connections play a role in the maintenance of interhemispheric functional connectivity
Effects of 238U variability and physical transport on water column 234Th downward fluxes in the coastal upwelling system off Peru
The eastern boundary region of the southeastern Pacific Ocean hosts one of the world's most dynamic and productive upwelling systems with an associated oxygen minimum zone (OMZ). The variability in downward export fluxes in this region, with strongly varying surface productivity, upwelling intensities and water column oxygen content, is however poorly understood. Thorium-234 (234Th) is a powerful tracer to study the dynamics of export fluxes of carbon and other elements, yet intense advection and diffusion in nearshore environments impact the assessment of depth-integrated 234Th fluxes when not properly evaluated. Here we use vessel-mounted acoustic Doppler current profiler (VmADCP) current velocities, satellite wind speed and in situ microstructure measurements to determine the magnitude of advective and diffusive fluxes over the entire 234Th flux budget at 25 stations from 11 to 16∘ S in the Peruvian OMZ. Contrary to findings along the GEOTRACES P16 eastern section, our results showed that weak surface wind speed during our cruises induced low upwelling rates and minimal upwelled 234Th fluxes, whereas vertical diffusive 234Th fluxes were important only at a few shallow shelf stations. Horizontal advective and diffusive 234Th fluxes were negligible because of small alongshore 234Th gradients. Our data indicated a poor correlation between seawater 238U activity and salinity. Assuming a linear relationship between the two would lead to significant underestimations of the total 234Th flux by up to 40 % in our study. Proper evaluation of both physical transport and variability in 238U activity is thus crucial in coastal 234Th flux studies. Finally, we showed large temporal variations on 234Th residence times across the Peruvian upwelling zone and cautioned future carbon export studies to take these temporal variabilities into consideration while evaluating carbon export efficiency
Machine learning analytics of resting-state functional connectivity predicts survival outcomes of glioblastoma multiforme patients
Glioblastoma multiforme (GBM) is the most frequently occurring brain malignancy. Due to its poor prognosis with currently available treatments, there is a pressing need for easily accessible, non-invasive techniques to help inform pre-treatment planning, patient counseling, and improve outcomes. In this study we determined the feasibility of resting-state functional connectivity (rsFC) to classify GBM patients into short-term and long-term survival groups with respect to reported median survival (14.6 months). We used a support vector machine with rsFC between regions of interest as predictive features. We employed a novel hybrid feature selection method whereby features were first filtered using correlations between rsFC and OS, and then using the established method of recursive feature elimination (RFE) to select the optimal feature subset. Leave-one-subject-out cross-validation evaluated the performance of models. Classification between short- and long-term survival accuracy was 71.9%. Sensitivity and specificity were 77.1 and 65.5%, respectively. The area under the receiver operating characteristic curve was 0.752 (95% CI, 0.62-0.88). These findings suggest that highly specific features of rsFC may predict GBM survival. Taken together, the findings of this study support that resting-state fMRI and machine learning analytics could enable a radiomic biomarker for GBM, augmenting care and planning for individual patients
Qd-tree: Learning Data Layouts for Big Data Analytics
Corporations today collect data at an unprecedented and accelerating scale,
making the need to run queries on large datasets increasingly important.
Technologies such as columnar block-based data organization and compression
have become standard practice in most commercial database systems. However, the
problem of best assigning records to data blocks on storage is still open. For
example, today's systems usually partition data by arrival time into row
groups, or range/hash partition the data based on selected fields. For a given
workload, however, such techniques are unable to optimize for the important
metric of the number of blocks accessed by a query. This metric directly
relates to the I/O cost, and therefore performance, of most analytical queries.
Further, they are unable to exploit additional available storage to drive this
metric down further.
In this paper, we propose a new framework called a query-data routing tree,
or qd-tree, to address this problem, and propose two algorithms for their
construction based on greedy and deep reinforcement learning techniques.
Experiments over benchmark and real workloads show that a qd-tree can provide
physical speedups of more than an order of magnitude compared to current
blocking schemes, and can reach within 2X of the lower bound for data skipping
based on selectivity, while providing complete semantic descriptions of created
blocks.Comment: ACM SIGMOD 202
- …