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Data Summary for the Near-Shore Sediment Characterization Task of the Clinch River Environmental Restoration Program
The purpose of the Near-Shore Sediment Characterization Task of the Clinch River Environmental Restoration Program (CR-ERP) was to quantify potential human health risks associated with Department of Energy (DOE)-related contamination of surface sediments in Watts Bar Reservoir (WBR). An estimated 700 Ci of {sup 137}Cs and 325 Ci of {sup 60}Co were released from White Oak Lake into the Clinch River between 1949 and 1992 (DOE, 1988). A number of previous studies have documented sediment contamination in the deep-water sediments but no study specifically targeted the near-shore environment, which has the most potential for exposure to humans
Does the continuum theory of dynamic fracture work?
We investigate the validity of the Linear Elastic Fracture Mechanics approach
to dynamic fracture. We first test the predictions in a lattice simulation,
using a formula of Eshelby for the time-dependent Stress Intensity Factor.
Excellent agreement with the theory is found. We then use the same method to
analyze the experiment of Sharon and Fineberg. The data here is not consistent
with the theoretical expectation.Comment: 4 page
Photons, neutrinos and optical activity
We compute the one-loop helicity amplitudes for low-energy
scattering and its crossed channels in the standard
model with massless neutrinos. In the center of mass, with , the cross sections for these channels grow roughly
as . The scattered photons in the elastic channel are circularly
polarized and the net value of the polarization is non-zero. We also present a
discussion of the optical activity of a sea of neutrinos and estimate the
values of its index of refraction and rotary power.Comment: 9 pages, ReVTeX4, 6 figures include
Axial vector current in an electromagnetic field and low-energy neutrino-photon interactions
An expression for the axial vector current in a strong, slowly varying
electromagnetic field is obtained. We apply this expression to the construction
of the effective action for low-energy neutrino-photon interactions.Comment: 6 pages, references updated, final version to appear in Phys. Rev.
Optical activity of neutrinos and antineutrinos
Using the one-loop helicity amplitudes for low-energy
and scattering in the standard model with
massless neutrinos, we study the optical activity of a sea of neutrinos and
antineutrinos. In particular, we estimate the values of the index of refraction
and rotary power of this medium in the absence of dispersion.Comment: Additional reference
WISP genes are members of the connective tissue growth factor family that are up-regulated in Wnt-1-transformed cells and aberrantly expressed in human colon tumors
Wnt family members are critical to many developmental processes, and components of the Wnt signaling pathway have been linked to tumorigenesis in familial and sporadic colon carcinomas. Here we report the identification of two genes, WISP-1 and WISP-2, that are up-regulated in the mouse mammary epithelial cell line C57MG transformed by Wnt-1, but not by Wnt-4. Together with a third related gene, WISP-3, these proteins define a subfamily of the connective tissue growth factor family. Two distinct systems demonstrated WISP induction to be associated with the expression of Wnt-1. These included (i) C57MG cells infected with a Wnt-1 retroviral vector or expressing Wnt-1 under the control of a tetracyline repressible promoter, and (ii) Wnt-1 transgenic mice. The WISP-1 gene was localized to human chromosome 8q24.1-8q24.3. WISP-1 genomic DNA was amplified in colon cancer cell lines and in human colon tumors and its RNA overexpressed (2- to >30-fold) in 84% of the tumors examined compared with patient-matched normal mucosa. WISP-3 mapped to chromosome 6q22-6q23 and also was overexpressed (4- to >40-fold) in 63% of the colon tumors analyzed. In contrast, WISP-2 mapped to human chromosome 20q12-20q13 and its DNA was amplified, but RNA expression was reduced (2- to >30-fold) in 79% of the tumors. These results suggest that the WISP genes may be downstream of Wnt-1 signaling and that aberrant levels of WISP expression in colon cancer may play a role in colon tumorigenesis
Second harmonic generation and birefringence of some ternary pnictide semiconductors
A first-principles study of the birefringence and the frequency dependent
second harmonic generation (SHG) coefficients of the ternary pnictide
semiconductors with formula ABC (A = Zn, Cd; B = Si, Ge; C = As, P) with
the chalcopyrite structures was carried out. We show that a simple empirical
observation that a smaller value of the gap is correlated with larger value of
SHG is qualitatively true. However, simple inverse power scaling laws between
gaps and SHG were not found. Instead, the real value of the nonlinear response
is a result of a very delicate balance between different intraband and
interband terms.Comment: 13 pages, 12 figure
Association Between Lifetime Marijuana Use and Cognitive Function in Middle Age: The Coronary Artery Risk Development in Young Adults (CARDIA) Study.
Marijuana use is increasingly common in the United States. It is unclear whether it has long-term effects on memory and other domains of cognitive function.
To study the association between cumulative lifetime exposure to marijuana use and cognitive performance in middle age.
We used data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a cohort of 5115 black and white men and women aged 18 to 30 years at baseline from March 25, 1985, to June 7, 1986 (year 0), and followed up over 25 years from June 7, 1986, to August 31, 2011, to estimate cumulative years of exposure to marijuana (1 year = 365 days of marijuana use) using repeated measures and to assess associations with cognitive function at year 25. Linear regression was used to adjust for demographic factors, cardiovascular risk factors, tobacco smoking, use of alcohol and illicit drugs, physical activity, depression, and results of the mirror star tracing test (a measure of cognitive function) at year 2. Data analysis was conducted from June 7, 1986, to August 31, 2011.
Three domains of cognitive function were assessed at year 25 using the Rey Auditory Verbal Learning Test (verbal memory), the Digit Symbol Substitution Test (processing speed), and the Stroop Interference Test (executive function).
Among 3385 participants with cognitive function measurements at the year 25 visit, 2852 (84.3%) reported past marijuana use, but only 392 (11.6%) continued to use marijuana into middle age. Current use of marijuana was associated with worse verbal memory and processing speed; cumulative lifetime exposure was associated with worse performance in all 3 domains of cognitive function. After excluding current users and adjusting for potential confounders, cumulative lifetime exposure to marijuana remained significantly associated with worse verbal memory. For each 5 years of past exposure, verbal memory was 0.13 standardized units lower (95% CI, -0.24 to -0.02; P = .02), corresponding to a mean of 1 of 2 participants remembering 1 word fewer from a list of 15 words for every 5 years of use. After adjustment, we found no associations with lower executive function (-0.03 [95% CI, -0.12 to 0.07]; P = .56) or processing speed (-0.04 [95% CI, -0.16 to 0.08]; P = .51).
Past exposure to marijuana is associated with worse verbal memory but does not appear to affect other domains of cognitive function
A Sawtooth-like Timeline for the First Billion Year of Lunar Bombardment
We revisit the early evolution of the Moon's bombardment. Our work combines
modeling (based on plausible projectile sources and their dynamical decay
rates) with constraints from the lunar crater record, radiometric ages of the
youngest lunar basins, and the abundance of highly siderophile elements in the
lunar crust and mantle. We deduce that the evolution of the impact flux did not
decline exponentially over the first billion years of lunar history, but also
there was no prominent and "narrow" impact spike some 3.9 Gy ago, unlike that
typically envisioned in the lunar cataclysm scenario. Instead, we show the
timeline of the lunar bombardment has a sawtooth-like profile, with an uptick
in the impact flux near 4.1 Gy ago. The impact flux at the beginning of this
weaker cataclysm was 5-10 times higher than the immediately preceding period.
The Nectaris basin should have been one of the first basins formed at the
sawtooth. We predict the bombardment rate since about 4.1Gy ago declined slowly
and adhered relatively close to classic crater chronology models (Neukum and
Ivanov (1994)). Overall we expect that the sawtooth event accounted for about
1/4 of the total bombardment suffered by the Moon since its formation.
Consequently, considering that about 12-14 basins formed during the sawtooth
event, we expect that the net number of basins formed on the Moon was about
45-50. From our expected bombardment timeline, we derived a new and improved
lunar chronology suitable for use on Pre-Nectarian surface units. According to
this chronology, a significant portion of the oldest lunar cratered terrains
has an age of 4.38-4.42 Gyr. Moreover, the largest lunar basin, South Pole
Aitken, is older than 4.3Gy, and therefore was not produced during the lunar
cataclysm.Comment: In press in EPS
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