353 research outputs found
The Collaborative Dialogue Panel: Changing The Model of The Professional Sociology Conference
The emergence of Sociologists Without Borders opened up new opportunities for social justice oriented intellectual engagement and collaboration. Given the opportunity to re-imagine the structure and function of professional conferences, a number of us who were focused on issues of environmental justice as a human right came together in 2006 to challenge the traditional model of serial paper presentations at panel sessions. The collaborative dialogue panel brings together sociologists focused on a specific social problem or issue, and asks them to work together to generate questions and answers in a public forum in dialogue with each other and with others attending a session. The goals of a collaborative dialogue panel are to replace serial monologues with sustained dialogue, address critical social issues, and to invite meaningful interaction between panelists and other participants. The idea is to maximize the unique benefits of bringing a group of engaged intellectuals physically together (at great ecological cost) to address social problems, and to leave the reading of papers to other times and places
Characterization of unsteady flow processes in a centrifugal compressor stage
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2006.Includes bibliographical references (p. 137).Numerical experiments have been implemented to characterize the unsteady loading on the rotating impeller blades in a modem centrifugal compressor. These consist of unsteady Reynolds-averaged Navier Stokes simulations of three-dimensional and quasi-two dimensional approximate models. The interaction between the rotating impeller and the stationary downstream diffuser has been identified as strong source of unsteady loading on the impeller blades. First of a kind unsteady calculations haven been carried out to elucidate an upstream manifestation of a downstream stimulus experienced in a particular centrifugal compressor stage. Here the upstream manifestation is the considerable unsteady loading in the splitter blade leading edge while the downstream stimulus is the unsteady impeller-diffuser interaction Three key parameters that control the level and extent of the unsteady loading are the impeller-diffuser gap, stage loading, and the impeller passage relative Mach number. Impeller-diffuser gap has been shown to control the peak level of unsteady loading on the blade. Stage loading has been shown to control the upstream attenuation of the loading.(cont.) A hypothesis has been put forward that increased diffusion associated with increased stage loading increases the impeller sensitivity to the downstream disturbance. The relative Mach number has been shown to set the chordwise distribution of the unsteady load on the blade. Unsteady blade loading has been computed through a quasi two-dimensional model in which an unsteady pressure boundary condition is imposed at the impeller exit to approximate the presence of the downstream diffuser. Results of this approximate model have been shown to yield unsteady loading characteristics that are in accord with the full three-dimensional unsteady model. An implied utility of this result is that a quasi-2D approximation could be used during the design phase to approximate the unsteady loading in a timeframe that is compatible with the design environment. The effect of unsteady flow on mass flow capacity of a fluid device is eliminated as a source for over-predictions in mass flow when a steady-state approximation is used.by Kenneth A. Gould.S.M
Microfibres and macroscopic films from the coordination-driven hierarchical self-assembly of cylindrical micelles
Anisotropic nanoparticles prepared from block copolymers are of growing importance as building blocks for the creation of synthetic hierarchical materials. However, the assembly of these structural units is generally limited to the use of amphiphilic interactions. Here we report a simple, reversible coordination-driven hierarchical self-assembly strategy for the preparation of micron-scale fibres and macroscopic films based on monodisperse cylindrical block copolymer micelles. Coordination of Pd(0) metal centres to phosphine ligands immobilized within the soluble coronas of block copolymer micelles is found to induce intermicelle crosslinking, affording stable linear fibres comprised of micelle subunits in a staggered arrangement. The mean length of the fibres can be varied by altering the micelle concentration, reaction stoichiometry or aspect ratio of the micelle building blocks. Furthermore, the fibres aggregate on drying to form robust, self-supporting macroscopic micelle-based thin films with useful mechanical properties that are analogous to crosslinked polymer networks, but on a longer length scale
High-throughput identification of genotype-specific cancer vulnerabilities in mixtures of barcoded tumor cell lines.
Hundreds of genetically characterized cell lines are available for the discovery of genotype-specific cancer vulnerabilities. However, screening large numbers of compounds against large numbers of cell lines is currently impractical, and such experiments are often difficult to control. Here we report a method called PRISM that allows pooled screening of mixtures of cancer cell lines by labeling each cell line with 24-nucleotide barcodes. PRISM revealed the expected patterns of cell killing seen in conventional (unpooled) assays. In a screen of 102 cell lines across 8,400 compounds, PRISM led to the identification of BRD-7880 as a potent and highly specific inhibitor of aurora kinases B and C. Cell line pools also efficiently formed tumors as xenografts, and PRISM recapitulated the expected pattern of erlotinib sensitivity in vivo
Fashionably Late? Building up the Milky Way's Inner Halo
Using a sample of 248 metal-poor stars (RR Lyraes, red giants and RHB stars)
which is remarkable for the accuracy of its 6-D kinematical data, we find a new
component for the local halo which has an axial ratio c/a ~ 0.2, a similar
flattening to the thick disk. It has a small prograde rotation but is supported
by velocity anisotropy, and contains more intermediate-metallicity stars (with
-1.5 < [Fe/H] < -1.0) than the rest of our sample. We suggest that this
component was formed quite late, during or after the formation of the disk. It
formed either from the gas that was accreted by the last major mergers
experienced by the Galaxy, or by dynamical friction of massive infalling
satellite(s) with the halo and possibly the stellar disk or thick disk. The
remainder of the stars in our sample exhibit a clumpy distribution in energy
and angular momentum, suggesting that the early, chaotic conditions under which
the inner halo formed were not violent enough to erase the record of their
origins. The clumpy structure suggests that a relatively small number of
progenitors were responsible for building up the inner halo, in line with
theoretical expectations. We find a difference in mean binding energy between
the RR Lyrae variables and the red giants in our sample, suggesting that more
of the RR Lyraes in the sample belong to the outer halo, and that the outer
halo may be somewhat younger, as first suggested by Searle and Zinn (1978). We
also find that the RR Lyrae mean rotation is more negative than the red giants,
which is consistent with the recent result of Carollo et al.(2007) that the
outer halo has a retrograde rotation and with the difference in kinematics seen
between RR Lyraes and BHB stars by Kinman et al.(2007).Comment: 16 pages, 10 figures, this version accepted by Ap
“How Long Have I Got?”—A Prospective Cohort Study Comparing Validated Prognostic Factors for Use in Patients with Advanced Cancer
© AlphaMed Press 2019 Background: The optimal prognostic factors in patients with advanced cancer are not known, as a comparison of these is lacking. The aim of the present study was to determine the optimal prognostic factors by comparing validated factors. Materials and Methods: A multicenter, prospective observational cohort study recruited patients over 18 years with advanced cancer. The following were assessed: clinician-predicted survival (CPS), Eastern Cooperative Oncology Group performance status (ECOG-PS), patient reported outcome measures (anorexia, cognitive impairment, dyspnea, global health), metastatic disease, weight loss, modified Glasgow Prognostic Score (mGPS) based on C-reactive protein and albumin, lactate dehydrogenase (LDH), and white (WCC), neutrophil (NC), and lymphocyte cell counts. Survival at 1 and 3 months was assessed using area under the receiver operating curve and logistic regression analysis. Results: Data were available on 478 patients, and the median survival was 4.27 (1.86–7.03) months. On univariate analysis, the following factors predicted death at 1 and 3 months: CPS, ECOG-PS, mGPS, WCC, NC (all
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