Inside the Black Box of Doctoral Education: What Program Characteristics Influence Doctoral Students’ Attrition and Graduation Probabilities?

[Excerpt] In this paper, we go inside the “black box” of graduate education to investigate what characteristics of graduate programs in the humanities and related social sciences actually influence PhD students’ attrition and graduation probabilities. We make use of data from the Graduate Education Survey; a retrospective survey of all graduate students who entered PhD programs in the treatment and control departments during the 1982-1997 period that was conducted by Mathematica Policy Research Inc. for the Mellon Foundation. After briefly describing the survey in the next section, section III outlines our methodological approach. Section IV presents our empirical findings and brief concluding remarks appear in section V. While our focus is on evaluating the effects of the GEI, we believe the methodological approach that we use can be profitably employed in a wide range of program evaluation studies

Inside the Black Box of Doctoral Education: What Program Characteristics Influence Doctoral Students' Attrition and Graduation Probabilities?

The Andrew W. Mellon Foundation's Graduate Education Initiative (GEI) provided over $80 million to 51 treatment departments in the humanities and related social sciences during the 1990s to improve their PhD programs. Using survey data collected from students who entered the treatment and 50 control departments during a 15 year period that spanned the start of the GEI, we use factor analysis to group multiple aspects of PhD programs into a smaller number of characteristics and then estimate which aspects of PhD programs the GEI influenced and how these different aspects influenced attrition and graduation probabilities. From these analyses, we identify the routes via which the GEI influenced attrition and graduation rates and also indicate which aspects of PhD programs departments should concentrate on if they want to improve their programs' performance.

The nature of iron-oxygen vacancy defect centers in PbTiO3

The iron(III) center in ferroelectric PbTiO3 together with an oxygen vacancy forms a charged defect associate, oriented along the crystallographic c-axis. Its microscopic structure has been analyzed in detail comparing results from a semi-empirical Newman superposition model analysis based on finestructure data and from calculations using density functional theory. Both methods give evidence for a substitution of Fe3+ for Ti4+ as an acceptor center. The position of the iron ion in the ferroelectric phase is found to be similar to the B-site in the paraelectric phase. Partial charge compensation is locally provided by a directly coordinated oxygen vacancy. Using high-resolution synchrotron powder diffraction, it was verified that lead titanate remains tetragonal down to 12 K, exhibiting a c/a-ratio of 1.0721.Comment: 11 pages, 5 figures, accepted in Phys. Rev.

Neglected diseases of neglected populations: Thinking to reshape the determinants of health in Latin America and the Caribbean

BACKGROUND: People living in poverty throughout the developing world are heavily burdened with neglected communicable diseases and often marginalized by the health sector. These diseases are currently referred to as Neglected Diseases of Neglected Populations. The neglected diseases create social and financial burdens to the individual, the family, the community, and the nation. DISCUSSION: Numerous studies of successful individual interventions to manage communicable disease determinants in various types of communities have been published, but few have applied multiple interventions in an integrated, coordinated manner. We have identified a series of successful interventions and developed three hypothetical scenarios where such interventions could be applied in an integrated, multi-disease, inter-programmatic, and/or inter-sectoral approach for prevention and control of neglected diseases in three different populations: a slum, an indigenous community, and a city with a mix of populations. SUMMARY: The objective of this paper is to identify new opportunities to address neglected diseases, improve community health and promote sustainable development in neglected populations by highlighting examples of key risk and protective factors for neglected diseases which can be managed and implemented through multi-disease-based, integrated, inter-programmatic, and/or inter-sectoral approaches. Based on a literature review, analysis and development of scenarios we visualize how multiple interventions could manage multiple disease problems and propose these as possible strategies to be tested. We seek to stimulate intra- and inter-sectoral dialogue which will help in the construction of new strategies for neglected diseases (particularly for the parasitic diseases) which could benefit the poor and marginalized based on the principle of sustainability and understanding of key determinants of health, and lead to the establishment of pilot projects and activities which can contribute to the achievement of the Millennium Development Goals

Fast Fluorescence Laser Tracking Microrheometry, II: Quantitative Studies of Cytoskeletal Mechanotransduction

Fluorescence laser tracking microrheometry (FLTM) is what we believe to be a novel method able to assess the local, frequency-dependent mechanical properties of living cells with nanometer spatial sensitivity at speeds up to 50 kHz. In an earlier article, we described the design, development, and optimization phases of the FLTM before reporting its performances in a variety of viscoelastic materials. In the work presented here, we demonstrate the suitability of FLTM to study local cellular rheology and obtain values for the storage and loss moduli G′(ω) and G″(ω) of fibroblasts consistent with past literature. We further establish that chemically induced cytoskeletal disruption is accompanied by reduced cellular stiffness and viscosity. Next, we provide a systematic study of some experimental variables that may critically influence microrheology measurements. First, we interrogate and justify the relevance of bead endocytosis as a method of cellular internalization of 1-μm probes in FLTM. Second, we show that as sample temperature increases, FLTM findings are elevated toward higher frequencies. Third, we confirm that relevant bead sizes (1 and 2 μm) have no effect on FLTM measurements. Fourth, we report the lack of influence of bead coatings (antiintegrin, antitransferrin, antidystroglycan, or uncoated tracers were surveyed) on their rheological readouts. Finally, we demonstrate the potential of FLTM in studying how substratum rigidity regulates cellular rheological properties. Interestingly, multiple, coupled strain relaxation mechanisms can be observed separated by two plateau moduli. Although these observations can be partly explained by rheological theories describing entangled actin filaments, there is a clear need to extend existing microrheology models to the cytoskeleton, including potentially important factors such as network geometry and remodeling