11,272 research outputs found
Reducing Disparities by way of a Cancer Disparities Research Training Program
Background: For minority populations, there is a continuing disparity in the burden of death and illness from cancer. Research to address this disparity should be conducted by investigators who can best understand and address the needs of culturally diverse communities. However, minorities are under-represented in health-related research. The goal of this project was to develop and evaluate an approach to motivating and preparing master’s degree students for careers dedicated to cancer disparities research.
Method: A Cancer Disparities Research Training Program (CDRTP) was initiated in 2010. The program consists of coursework, practicum experiences, and research opportunities. Assessment of the curriculum is based on monitoring achievement of evaluation indicators and includes a quantitative assessment and qualitative approach.
Results: In its first three years, the program graduated 20 trainees, all of whom were minorities (18 African Americans and two Asians). When asked about career goals, two-thirds of the trainees indicated interest in pursuing careers in research on cancer prevention and control. The trainees expressed high satisfaction with the courses, instructor, materials, and curriculum. Although trainees had suggestions about course details, evaluations overall were positive. Across focus groups, three recurrent themes emerged regarding activities to enhance the student experience: having a wider variety of topics, more guest speakers, and field trips.
Conclusion: The CDRTP was intended to recruit students – primarily African Americans – into research on prevention and control of cancer disparities. Although final evaluation of the program’s overall outcome will not be available for several years, a preliminary evaluation indicates the program is being successful
Perturbative matching of staggered four-fermion operators with hypercubic fat links
We calculate the one-loop matching coefficients between continuum and lattice
four-fermion operators for lattice operators constructed using staggered
fermions and improved by the use of fattened links. In particular, we consider
hypercubic fat links and SU(3) projected Fat-7 links, and their mean-field
improved versions. We calculate only current-current diagrams, so that our
results apply for operators whose flavor structure does not allow
``eye-diagrams''. We present general formulae, based on two independent
approaches, and give numerical results for the cases in which the operators
have the taste (staggered flavor) of the pseudo-Goldstone pion. We find that
the one-loop corrections are reduced down to the 10-20% level, resolving the
problem of large perturbative corrections for staggered fermion calculations of
matrix elements.Comment: 37 pages, no figure, 20 table
Nonvolatile memory with molecule-engineered tunneling barriers
We report a novel field-sensitive tunneling barrier by embedding C60 in SiO2
for nonvolatile memory applications. C60 is a better choice than ultra-small
nanocrystals due to its monodispersion. Moreover, C60 provides accessible
energy levels to prompt resonant tunneling through SiO2 at high fields.
However, this process is quenched at low fields due to HOMO-LUMO gap and large
charging energy of C60. Furthermore, we demonstrate an improvement of more than
an order of magnitude in retention to program/erase time ratio for a metal
nanocrystal memory. This shows promise of engineering tunnel dielectrics by
integrating molecules in the future hybrid molecular-silicon electronics.Comment: to appear in Applied Physics Letter
ADAM10 Regulates Transcription Factor Expression Required for Plasma Cell Function
A disintegrin and metalloprotease 10 (ADAM10) is a key regulator of cellular processes by shedding extracellular domains of transmembrane proteins. We have previously demonstrated that deletion of B cell expressed ADAM10 results in changes in lymphoid tissue architecture and impaired germinal center (GC) formation. In this study, mice were generated in which ADAM10 is deleted in B cells following class switch recombination (ADAM10Δ/ΔIgG1-cre+/−mice). Despite normal GC formation, antibody responses were impaired in ADAM10Δ/ΔIgG1-cre+/− mice, implicating ADAM10 in post-GC and extrafollicular B cell terminal differentiation. Surprisingly, plasma cell (PC) numbers were normal in ADAM10Δ/ΔIgG1-cre+/− mice when compared to controls. However, PCs isolated from ADAM10Δ/ΔIgG1-cre+/− mice exhibited decreased expression of transcription factors important for PC function: Prdm1, Xbp1 and Irf4.Bcl6 is a GC transcriptional repressor that inhibits the PC transcriptional program and thus must be downregulated for PC differentiation to occur. Bcl6 expression was increased in PCs isolated from ADAM10Δ/ΔIgG1-cre+/− mice at both the mRNA and protein level. These results demonstrate that ADAM10 is required for proper transcription factor expression in PCs and thus, for normal PC function
Resistivity scaling and critical dynamics of fully frustrated Josephson-junction arrays with on-site dissipation
We study the scaling behavior and critical dynamics of the resistive
transition in Josephson-junction arrays, at f=1/2 flux quantum per plaquette,
by numerical simulation of an on-site dissipation model for the dynamics. The
results are compared with recent simulations using the
resistively-shunted-junction model. For both models, we find that the
resistivity scaling and critical dynamics of the phases are well described by
the same critical temperature as for the chiral (vortex-lattice) transition,
with a power-law divergent correlation length. The behavior is consistent with
the single transition scenario, where phase and chiral variables order at the
same temperature, but with different dynamic exponents z for phase coherence
and chiral order.Comment: 17 pages, 13 figures, to appear in Phys. Rev.
A controlled study of cold dust content in galaxies from
At , the formation of new stars is dominated by dusty galaxies whose
far-IR emission indicates they contain colder dust than local galaxies of a
similar luminosity. We explore the reasons for the evolving IR emission of
similar galaxies over cosmic time using: 1) Local galaxies from GOALS ; 2) Galaxies at from the 5MUSES
(); 3) IR luminous galaxies spanning
from GOODS and Spitzer xFLS (). All
samples have Spitzer mid-IR spectra, and Herschel and ground-based
submillimeter imaging covering the full IR spectral energy distribution,
allowing us to robustly measure ,
, and for every galaxy. Despite similar infrared
luminosities, dusty star forming galaxies have a factor of 5 higher
dust masses and 5K colder temperatures. The increase in dust mass is linked
with an increase in the gas fractions with redshift, and we do not observe a
similar increase in stellar mass or star formation efficiency.
, a proxy
for , is strongly correlated with independently of redshift. We
measure merger classification and galaxy size for a subsample, and there is no
obvious correlation between these parameters and or . In dusty star forming galaxies, the
change in can fully
account for the observed colder dust temperatures, suggesting that any change
in the spatial extent of the interstellar medium is a second order effect.Comment: Accepted for publication in ApJ. 21 pages, 11 figure
SpinWaves in the Frustrated Kagomé Lattice Antiferromagnet KFe\u3csub\u3e3\u3c/sub\u3e(OH)\u3csub\u3e6\u3c/sub\u3e(SO\u3csub\u3e4\u3c/sub\u3e)\u3csub\u3e2\u3c/sub\u3e
The spin wave excitations of the S = 5/2 kagomé lattice antiferromagnet KFe3(OH)6(SO4)2 have been measured using high-resolution inelastic neutron scattering. We directly observe a flat mode which corresponds to a lifted ‘‘zero energy mode,’’ verifying a fundamental prediction for the kagomé lattice. A simple Heisenberg spin Hamiltonian provides an excellent fit to our spin wave data. The antisymmetric Dzyaloshinskii-Moriya interaction is the primary source of anisotropy and explains the low-temperature magnetization and spin structure
Perturbative Matching of the staggered four-fermion operators for e'/e
Using staggered fermions, we calculate the perturbative corrections to the
bilinear and four-fermion operators that are used in the numerical study of
weak matrix elements for . We present results for one-loop
matching coefficients between continuum operators, calculated in the Naive
Dimensional Regularization (NDR) scheme, and gauge invariant staggered fermion
operators. These results, combined with existing results for penguin diagrams,
provide the complete one-loop renormalization of the staggered four-fermion
operators.Comment: 36 pages. will appear in physical review
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