Design Constraints and Reconstruction Algorithms for Traverse-Continuous-Rotate CT Scanners

In this paper a new configuration for a computerized tomographic (CT) scanner is presented. The machine is essentially a hybrid combination of second- and third-generation scanners. A single source of X-rays and an array of detectors are mounted on a gantry. The source/detector array grouping traverses the object while the gantry continuously rotates around the object. Conditions will be derived so that the projection data will completely cover the Radon space without any holes or partial overlaps, thus ensuring the existence of efficiently implementable reconstruction algorithms for inverting the data. We will also present a new convolution-backprojection algorithm for reconstructing tomographic images from data generated on such a scanner.     

Bremsstrahlung energy spectra from electrons of kinetic energy 1 keV ≤ T1 ≤ 2000 keV incident on neutral atoms 2 ≤ Z ≤ 92

A tabulation is presented of theoretical predictions for the electron bremsstrahlung energy spectrum from neutral atoms as a function of atomic number Z, incident electron kinetic energy T₁, and fraction of energy radiated $\text{k}\text{T}{}_1$. Tabulated values were obtained by interpolation from a smaller set of calculated data points. These calculated points were obtained by describing bremsstrahlung as a single-electron transition in a relativistic self-consistent screened potential and, after expansions in partial waves, by performing a numerical evaluation for radial wavefunctions and matrix elements.     

Highlights in the development of the Human Resources Research Organization (HumRRO).

Traces the development of HumRRO from its establishment in 1951 at the request of the US Department of the Army to perform research in training methods, motivation, morale and leadership, and psychological warfare to its current status as an independent, nonprofit corporation engaged in research and development to improve human performance in various organizational settings. Four points of contrast between HumRRO's operation as a Federal Contract Research Center and as an independent contractor are examined. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic analysis of the South Altaian population of the Mendur-Sokkon village, Altai Republic

This study was a continuation of complex research on the gene pool of indigenous Siberian populations conducted at the Institute of Cytology and Genetics, Siberian Division, Russian Academy of Sciences. In the population of South Altaians from the Mendur-Sokkon village, Ust'-Kanskii raion, Altai Republic, polymorphism for the following genetic markers was studied: blood groups ABO, MNSs, Rhesus, Kell, Duffy, and P; erythrocyte acid phosphatase (AcP); phosphoglucomutase 1 (PGM1); haptoglobin (Hp); and transferrin (Tf). The genetic position of South Altaians relative to the populations of the European part of Russia, Siberia, and the Urals was estimated. It was demonstrated that the gene pool of the South Altaian population of Mendur-Sokkon possessed both Caucasoid and Mongoloid genetic characteristics, with the latter prevailing. Genetically, this population is most closely related to Mongols and Nentsis. The genetic distance between South and North Altaians was large; this agreed with earlier genetic data and confirmed anthropological and ethnographic evidence indicating that these two groups had different backgrounds and were at different stages of ethnogenesis.     

Interrelationships among disablement concepts

BACKGROUND: Understanding interrelationships among disablement concepts is critical to the design of future disability treatment and prevention interventions. METHODS: This study uses cross-sectional data to examine the relationships among physiologic impairments, functional limitations, and disability in a moderately disabled sample of 207 community-dwelling older adults. RESULTS: As hypothesized, the data revealed statistically significant curvilinear relationships of upper and lower extremity strength and balance with mobility in this older sample. Multivariate analyses further clarified the hypothesized causal mechanism among the disablement concepts by demonstrating that most of the association of muscle strength and balance with disability was through the intermediary role of mobility limitations. CONCLUSIONS: The findings from this study highlight the value of clinical trials that focus on prevention or treatment of mobility limitations as a means of preventing disability; our findings underscore the need for future research that examines the effects of other variables believed to influence disablement in late life.     

Multilocus linkage identifies two new loci for a mendelian form of stroke, cerebral cavernous malformation, at 7p15-13 and 3q25.2-27

Cerebral cavernous malformation (CCM) is a Mendelian model of stroke, characterized by focal abnormalities in small intracranial blood vessels leading to hemorrhage and consequent strokes and/or seizures. A significant fraction of cases is inherited as an autosomal dominant trait with incomplete penetrance. Among Hispanic Americans, virtually all CCM is attributable to a founder mutation localized to 7q ( CCM1 ). Recent analysis of non-Hispanic Caucasian kindreds, however, has excluded linkage to 7q in some, indicating at least one additional CCM locus. We now report analysis of linkage in 20 non-Hispanic Caucasian kindreds with familial CCM. In addition to linkage to CCM1, analysis of linkage demonstrates linkage to two new loci, CCM2 at 7p13-15 and CCM3 at 3q25.2-27. Multilocus analysis yields a maximum lod score of 14.11, with 40% of kindreds linked to CCM1, 20% linked to CCM2 and 40% linked to CCM3, with highly significant evidence for linkage to three loci (linkage to three loci supported with an odds ratio of 2.6 x 10(5):1 over linkage to two loci and 1.6 x 10(9):1 over linkage to one locus). Multipoint analysis among families with high posterior probabilities of linkage to each locus refines the locations of CCM2 and CCM3 to approximately 22 cM intervals. Linkage to these three loci can account for inheritance of CCM in all kindreds studied. Significant locus-specific differences in penetrance are identified. These findings have implications for genetic testing of this disorder and represent an important step toward identification of the molecular basis of this disease.     

Incomplete dominance of the gene for naked neck in domestic fowl

The autosomal gene for naked neck in domestic fowl has been shown to be incompletely dominant. Heterozygotes characteristically have an isolated tuft of feathers on the ventral side of the neck above the crop. Homozygotes lack this tuft completely, or it may be reduced to a very few pinfeathers or small feathers.