Excitation Mechanisms of the Nitrogen First‐Positive and First‐Negative Radiation at High Temperature

The kinetic mechanisms responsible for the excitation of the first-positive and first-negative emission of nitrogen have been investigated in a re-examination of previously reported shock-tube measurements of the nonequilibrium radiation for these systems. The rate coefficients of the collisional quenching reactions, N_2(A^(3)Σ^(+)_u)(^(k^(N)_(-2))⇒) N_2(X^(1)Σ^(+)_g) + N(^(4)S) and N^(+)_2(B^(2)Σ^(+)_u) + N_2(X^(1)Σ^(+)_g)(^(k^(N)_(q))⇒) N^(+)_2(X^(2)Σ^(+)_g) or N^(+)_2(A(^(2)II_u)+N_2(X^(1)Σ^(+)_g) were found to be given by the empirical expressions, k_(2^(N))=5.1x10^(-3)T^(-2.23) cm^3 sec^(-1) and k_(q^(N_2))=1.9x10^(-2)T^(-2.33)cm^3 sec^(-1), respectively, over the approximate temperature range 6000-14 000°K

Probing the Evolution of the Galaxy Interaction/Merger Rate Using Collisional Ring Galaxies

We present the results from our program to determine the evolution of the galaxy interaction/merger rate with redshift using the unique star-forming characteristics of collisional ring galaxies. We have identified 25 distant collisional ring galaxy candidates (CRGCs) in a total of 162 deep Hubble Space Telescope Wide Field/Planetary Camera-2 images obtained from the HST Archives. Based on measured and estimated redshifts, these 25 CRGCs all lie in the redshift interval of 0.1 < z < 1. Using the local collisional ring galaxy volume density and the new ``standard'' cosmology, we find that in order to account for the number of identified CRGCs in our surveyed fields, the galaxy interaction/merger rate, parameterized as (1 + z)^m, must increase steeply with redshift.We determine a minimum value of m = 5.2 $\pm$ 0.7, though m could be as high as 7 or 8. We can rule out a non-evolving (m = 0) and weakly evolving (m = 1-2) galaxy interaction/merger rate at greater than the 4 sigma level of confidence.Comment: Accepted in the Astrophysical Journal (11 pages, 4 figures). Higher resolution version of the figures is available at http://www.astro.cornell.edu/~vassilis/papers

Corrosion fatigue of a C-Mn steel

Summary available: p. i

Reforms in Japanese Criminal Procedure Under Allied Occupation

In the past, reforms in Japanese criminal procedure would have been of little interest to most Americans, who have never felt it important to understand foreign legal systems. Fortunately, this attitude is beginning to change. Moreover, the United States has been officially committed to encourage a desire for individual liberties and democratic processes on the part of the Japanese people since the Potsdam Declaration of July 26, 1945. Consequently, Americans will be interested in the postwar reforms in Japanese criminal procedure, if only to be fully informed of progress toward fulfillment of the objectives of the Allied Occupation, in which the United States has played the leading role

Neutral hydrogen surveys for high redshift galaxy clusters and proto-clusters

We discuss the possibility of performing blind surveys to detect large-scale features of the universe using 21cm emission. Using instruments with approx. 5'-10' resolution currently in the planning stage, it should be possible to detect virialized galaxy clusters at intermediate redshifts using the combined emission from their constituent galaxies, as well as less overdense structures, such as proto-clusters and the `cosmic web', at higher redshifts. Using semi-analytic methods we compute the number of virialized objects and those at turnaround which might be detected by such surveys. We find a surprisingly large number of objects might be detected even using small (approx. 5%) bandwidths and elaborate on some issues pertinent to optimising the design of the instrument and the survey strategy. The main uncertainty is the fraction of neutral gas relative to the total dark matter within the object. We discuss this issue in the context of the observations which are currently available.Comment: 10 pages, 6 figure

The social cognition of medical knowledge, with special reference to childhood epilepsy

This paper arose out of an engagement in medical communication courses at a Gulf university. It deploys a theoretical framework derived from a (critical) sociocognitive approach to discourse analysis in order to investigate three aspects of medical discourse relating to childhood epilepsy: the cognitive processes that are entailed in relating different types of medical knowledge to their communicative context; the types of medical knowledge that are constituted in the three different text types analysed; and the relationship between these different types of medical knowledge and the discursive features of each text type. The paper argues that there is a cognitive dimension to the human experience of understanding and talking about one specialized from of medical knowledge. It recommends that texts be studied in medical communication courses not just in terms of their discrete formal features but also critically, in terms of the knowledge which they produce, transmit and reproduce

Genetic regulation of gene expression in the epileptic human hippocampus

Epilepsy is a serious and common neurological disorder. Expression quantitative loci (eQTL) analysis is a vital aid for the identification and interpretation of disease-risk loci. Many eQTLs operate in a tissue- and condition-specific manner. We have performed the first genome-wide cis-eQTL analysis of human hippocampal tissue to include not only normal (n = 22) but also epileptic (n = 22) samples. We demonstrate that disease-associated variants from an epilepsy GWAS meta-analysis and a febrile seizures (FS) GWAS are significantly more enriched with epilepsy-eQTLs than with normal hippocampal eQTLs from two larger independent published studies. In contrast, GWAS meta-analyses of two other brain diseases associated with hippocampal pathology (Alzheimer’s disease and schizophrenia) are more enriched with normal hippocampal eQTLs than with epilepsy-eQTLs. These observations suggest that an eQTL analysis that includes disease-affected brain tissue is advantageous for detecting additional risk SNPs for the afflicting and closely related disorders, but not for distinct diseases affecting the same brain regions. We also show that epilepsy eQTLs are enriched within epilepsy-causing genes: an epilepsy cis-gene is significantly more likely to be a causal gene for a Mendelian epilepsy syndrome than to be a causal gene for another Mendelian disorder. Epilepsy cis-genes, compared to normal hippocampal cis-genes, are more enriched within epilepsy-causing genes. Hence, we utilize the epilepsy eQTL data for the functional interpretation of epilepsy disease-risk variants and, thereby, highlight novel potential causal genes for sporadic epilepsy. In conclusion, an epilepsy-eQTL analysis is superior to normal hippocampal tissue eQTL analyses for identifying the variants and genes underlying epilepsy

The draft genome of the parasitic nematode Trichinella spiralis

Genome evolution studies for the phylum Nematoda have been limited by focusing on comparisons involving Caenorhabditis elegans. We report a draft genome sequence of Trichinella spiralis, a food-borne zoonotic parasite, which is the most common cause of human trichinellosis. This parasitic nematode is an extant member of a clade that diverged early in the evolution of the phylum, enabling identification of archetypical genes and molecular signatures exclusive to nematodes. We sequenced the 64-Mb nuclear genome,which is estimated to contain 15,808 protein-coding genes,at ~35-fold coverage using whole-genome shotgun and hierarchal map–assisted sequencing. Comparative genome analyses support intrachromosomal rearrangements across the phylum, disproportionate numbers of protein family deaths over births in parasitic compared to a non-parasitic nematode and a preponderance of gene-loss and -gain events in nematodes relative to Drosophila melanogaster. This genome sequence and the identified pan-phylum characteristics will contribute to genome evolution studies of Nematoda as well as strategies to combat global parasites of humans, food animals and crops