35 research outputs found
Formation of the Terrestrial Planets from a Narrow Annulus
We show that the assembly of the Solar System terrestrial planets can be
successfully modelled with all of the mass initially confined to a narrow
annulus between 0.7 and 1.0 AU. With this configuration, analogues of Mercury
and Mars often form from the collisional evolution of material diffusing out of
the annulus under the scattering of the forming Earth and Venus analogues. The
final systems also possess eccentricities and inclinations that match the
observations, without recourse to dynamical friction from remnant small body
populations. Finally, the characteristic assembly timescale for Earth analogues
is rapid in this model, and consistent with cosmochemical models based on the
Hf--W isotopes. The agreement between this model and the
observations suggests that terrestrial planet systems may also be formed in
`planet traps', as has been proposed recently for the cores of giant planets in
our solar system and others.Comment: 37 pages, 16 figures. to appear in Ap
Two new topologically ordered glass phases of smectics confined in anisotropic random media
We show that smectic liquid crystals confined in_anisotropic_ porous
structures such as e.g.,_strained_ aerogel or aerosil exhibit two new glassy
phases. The strain both ensures the stability of these phases and determines
their nature. One type of strain induces an ``XY Bragg glass'', while the other
creates a novel, triaxially anisotropic ``m=1 Bragg glass''. The latter
exhibits anomalous elasticity, characterized by exponents that we calculate to
high precision. We predict the phase diagram for the system, and numerous other
experimental observables.Comment: 4 RevTeX pgs, 2 eps figures, submitted to Phys. Rev. Let
Topologically ordered phases of smectics confined in anisotropic random media: smectic Bragg glasses
International Recommendations for Training Future Toxicologic Pathologists Participating in Regulatory-Type, Nonclinical Toxicity Studies*
The International Federation of Societies of Toxicologic Pathologists (IFSTP) proposes a
common global framework for training future toxicologic pathologists who will support
regulatory-type nonclinical toxicology studies. Trainees optimally should undertake a
scientific curriculum of at least 5 years at an accredited institution leading to a
clinical degree (veterinary medicine or medicine). Trainees should then obtain 4 or more
years of intensive pathology practice during a residency and/or on-the-job
“apprenticeship,” at least 2 years of which must be focused on regulatory-type toxicologic
pathology topics. Possession of a recognized pathology qualification (i.e., certification)
is highly recommended. A non-clinical pathway (e.g., a graduate degree in medical biology
or pathology) may be possible if medically trained pathologists are scarce, but this
option is not optimal. Regular, lifelong continuing education (peer review of nonclinical
studies, professional meetings, reading, short courses) will be necessary to maintain and
enhance one’s understanding of current toxicologic pathology knowledge, skills, and tools.
This framework should provide a rigorous yet flexible way to reliably train future
toxicologic pathologists to generate, interpret, integrate, and communicate data in
regulatory-type, nonclinical toxicology studies
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Occam's Razor and Petascale Visual Data Analysis
One of the central challenges facing visualization research is how to effectively enable knowledge discovery. An effective approach will likely combine application architectures that are capable of running on today?s largest platforms to address the challenges posed by large data with visual data analysis techniques that help find, represent, and effectively convey scientifically interesting features and phenomena
Multiplatform Analysis of 12 Cancer Types Reveals Molecular Classification within and across Tissues of Origin
Recent genomic analyses of pathologically-defined tumor types identify “within-a-tissue” disease subtypes. However, the extent to which genomic signatures are shared across tissues is still unclear. We performed an integrative analysis using five genome-wide platforms and one proteomic platform on 3,527 specimens from 12 cancer types, revealing a unified classification into 11 major subtypes. Five subtypes were nearly identical to their tissue-of-origin counterparts, but several distinct cancer types were found to converge into common subtypes. Lung squamous, head & neck, and a subset of bladder cancers coalesced into one subtype typified by TP53 alterations, TP63 amplifications, and high expression of immune and proliferation pathway genes. Of note, bladder cancers split into three pan-cancer subtypes. The multi-platform classification, while correlated with tissue-of-origin, provides independent information for predicting clinical outcomes. All datasets are available for data-mining from a unified resource to support further biological discoveries and insights into novel therapeutic strategies
Topologically ordered phases of smectics confined in anisotropic random media: smectic Bragg glasses
We report the existence of two new topologically ordered glass phases of smectics in strained aerogel. In contrast to the case of unstrained aerogel, we find compelling theoretical arguments that a smectic in uniaxially stretched aerogel exhibits, for homeotropic nematic-aerogel alignment, a `smectic Bragg glass\u27 in the universality class of the `XY Bragg glass\u27. On the other hand, a uniaxial compression, with homeotropic alignment, leads to an entirely novel type of anisotropic smectic elastic glass phase that we call the `m = 1 Bragg glass\u27. This latter phase exhibits anomalous elasticity, characterized by exponents that we calculate to high precision. We present a phase diagram for the system in the aerogel density-strain parameter space, which should be accessible experimentally. We also make numerous other scaling predictions for experimentally observable quantities
Smoking, Rural Residence and Diabetes as Risk Factors for Presumed Ocular Histoplasmosis Syndrome
PURPOSE: To investigate the relationship of smoking, urbanicity and diabetes to presumed ocular histoplasmosis syndrome (POHS) and associated choroidal neovascularization (CNV).
METHODS: Medical records of 751 adult patients with POHS were reviewed, including 603 patients without CNV and 148 patients with CNV. Age- and gender-matched controls were randomly selected from the same practice for comparison. Statistical comparisons of smoking history, urbanicity, and diabetic history were performed using Chi-Square and conditional logistic regression analyses.
RESULTS: Increased rates of current or former smoking, rural residence, and diabetes were found in patients with POHS compared with controls. POHS patients with CNV had increased rates of current or former smoking and rural residence as compared with controls.
CONCLUSIONS: A history of current or past smoking is associated with an increased risk of developing both POHS alone and POHS with CNV. We did not find a significant additional risk of smoking on the development of CNV in patients with POHS. Patients living in rural locations are more likely than those in urban locations to develop both POHS and POHS with CNV. Diabetics may be more likely to develop POHS than non-diabetics