9,404 research outputs found
Using Technology to Enhance Pre-Service Teacher Preparation
Use of the internet to deliver a portion of the content in an introductory science, education, and technology methods course for pre-service teachers provides an opportunity for a much needed introduction to basic computer literacy. A web page was developed for use in conjunction with the math, science, and technology educational methods courses at Brooklyn College. Students are introduced to this page as a group in the computer lab, and work in small groups with more experienced students serving as mentors to other students. The Brooklyn College Science Education Webpage is designed as a simple jump page with links to various resources for science education. It serves as a starting point to expose pre-service teachers to a wide range of resources available to them on the world wide web and in the real world. Students use their internet research skills in open-ended assignments throughout the semester. The web page continues to serve as a resource for students in the next courses in the math and science education sequence. The Brooklyn College Science Education Webpage helps education graduates to begin their teaching better prepared to use technology in the classroom
Buffer overflow vulnerabilities in CUDA: a preliminary analysis
We present a preliminary study of buffer overflow vulnerabilities in CUDA
software running on GPUs. We show how an attacker can overrun a buffer to
corrupt sensitive data or steer the execution flow by overwriting function
pointers, e.g., manipulating the virtual table of a C++ object. In view of a
potential mass market diffusion of GPU accelerated software this may be a major
concern.Comment: 12 pages, 2 figure
Quantum Statistics and Parton Distributions
A novel approach to parton distributions parameterization in terms of quantum
statistical functions is here outlined. The description, already proposed in
previous publications, is here improved by adding to the statistical
distributions an unpolarized {\it liquid} component. This new contribution to
fermion partons is able to reproduce the expected low behaviour of
structure functions. The analysis provides a satisfactory description of
polarized and unpolarized deep inelastic data and shows a possible connection
between the Gottfried and Bjorken sum rules.Comment: 20 pages, LaTeX, 8 epsfigures as uuencoded file. Contributed paper to
LP9
Transcriptional landscape of neuronal and cancer stem cells
Tumor mass is composed by heterogeneous cell population including a subset of “cancer stem cells” (CSC).
Oncogenic signals foster CSC by transforming tissue stem cells or by reprogramming progenitor/differentiated
cells towards stemness. Thus, CSC share features with cancer and stem cells (e.g. self-renewal, hierarchical
developmental program leading to differentiated cells, epithelial/mesenchimal transition) and these latter are
maintained by the constitutive activation of stemness-promoting signals. CSC could trigger tumor formation,
drive to resistance to conventional therapeutics and underlie patients’ relapse. Indeed, stem cell signatures
have been associated with poor prognosis in various.
This background makes the identification of CSC molecular features mandatory to highlight the survival inner
working and to design novel CSC specific therapeutic strategies.
Medulloblastoma (MB) is the most common childhood malignant brain tumor and a leading cause of cancerrelated
morbidity and mortality. Current multimodal therapies are effective in about 50% of patients but often
cause long-term side effects, i.e. developmental, neurological, neuroendocrine and psychosocial deficits
(Northcott PA Nature Rev cancer 2012). For many years, MB treated as a single tumor entity despite the
divergent tumor histology, patients’ outcome and drug sensitivity, and also by the diversity of the stem cell of
origin. Very recently the scenario of human MB has dramatically changed since its heterogeneous biology has
been addressed by high-throughput gene expression analysis (oligonucleotide microarrays) or by the powerful
genomic next-generation sequencing. These led to the identification of four tumor subgroups (WNT, SHH,
Group 3 and Group 4) uncovering the existence of a highly diverse mutational spectra and gene expression.
However a quantitative approach has not yet been applied to the transcriptional landscape of Medulloblastoma
stem cells (MbSC) through RNA Next Generation Sequencing (RNA-Seq) technology. This is a relevant issue,
since RNA-Seq is able to interrogate the genome wide global transcriptome including new transcripts,
alternative spliced isoforms and non-coding RNAs.
Lower rhombic lip progenitors of the dorsal brainstem are considered the trigger cells in WNT tumors; in SHH
subgroup initiation cells are Prominin1+ CD15+ stem cells from the subventricular zone requiring the
commitment to Math1+ granule cell progenitors [GCP] of the external granule cell layer [EGL]; while Math1+ or
Math1- EGL-GCP or Prominin1+/lineage-negative stem cells sustain the MYC driven Group 3.
MbSC derived from SHH tumors and postnatal normal cerebellar stem cells (NcSC) have been reported to
share several features. A key signal for both of them is Hedgehog. Furthermore, both NcSC and MbSC display
up-regulation of stemness genes (e.g Sox2, Nestin, Nanog, Prom1). Finally, constitutive activation of the Shh
pathway by conditional deletion of Ptch1 inhibitory receptor in NcSC, promote medulloblastoma in vivo,
producing a mouse model of the human SHH tumor. Acquisition of stemness features may therefore represent
the first step of oncogenic conversion. Cooperation with additional oncogenic signals is however needed to
enhance MbSC tumorigenicity.
In order to understand the MbSCs transcriptional programs, we analyze by RNA-Seq, MbSC derived from
Ptch1+/- tumors (Ptch1+/- MbSC). This choice, of a genetically determined model of MB, has allowed us to
work with Ptch1+/- MbSC together with appropriate NcSC counterpart, and to analyze biological replicates
doing statistical analysis.
We identify a number of transcripts, annotated ones, novel isoforms, and long non-coding RNAs,
characterizing MbSC and/or NcSC. Some of these genes control stemness or are cancer related and
conserved in human medulloblastomas. Interestingly a subset of them, belonging to cell stress response, are
of prognostic relevance being significantly related to clinical outcome. Correlation of genes expression
characterizing MbSC with survival information from our human medulloblastomas database further
demonstrates the significance of these findings. Our data suggest that the modulation of normal and cancer
stem cell functions observed in vitro is effective in dissecting the transcriptional programs underlying the in
vivo behavior of human medulloblastomas
Optimum lifting wings in Newtonian flow Progress report, Jan. 1 - Jun. 30, 1966
Lift-drag ratios analyzed for lifting wings in hypersonic flo
Gradient techniques for aerospace applications Final report, 1 Jun. 1969 - 31 May 1970
Gradient techniques in optimization theory with aerospace applicabilit
Method of Particular Solutions for Linear, Two-point Boundary-value Problems. Part 1 - Preliminary Examples
Particular solutions for linear two-point boundary value problems with regard to digital computer
Optimal flight trajectories in the presence of windshear, 1984-86
Optimal flight trajectories were determined in the presence of windshear and guidance schemes were developed for near optimum flight in a windshear. This is a wind characterized by sharp change in intensity and direction over a relatively small region of space. This problem is important in the takeoff and landing of both civilian airplanes and military airplanes and is key to aircraft saftey. The topics covered in reference to takeoff problems are: equations of motion, problem formulation, algorithms, optimal flight trajectories, advanced guidance schemes, simplified guidance schemes, and piloting strategies
Optimization and guidance of flight trajectories for the national aerospace plane
The research on optimal trajectories for the National Aerospace Plane (NASP) performed by the Aero-Astronautics Group of Rice University from June 22, 1989 to December 31, 1990 is summarized. The aerospace plane is assumed to be controlled via the angle of attack and the power setting. The time history of the controls is optimized simultaneously with the switch times from one powerplant to another and the final time. The intent is to arrive at NASP guidance trajectories exhibiting many of the desirable characteristics of NASP optimal trajectories
Optimal trajectories for the aeroassisted flight experiment, 1988-89
Research is summarized on optimal trajectories for the aeroassisted flight experiment, performed by the Aero-Astronautics Group of Rice University during the period 1988 through 1989. This research includes the following topics: (1) equations of motion in an Earth-fixed system; (2) equations of motion in an inertial system; (3) formultion of the optimal trajectory problem; (4) results on the optimal trajectory problem; and (5) guidance implications
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