Longitudinal bone mineral density changes in early rheumatoid arthritis

A prospective longitudinal study of patients with early RA was performed to examine the influence of disease duration, disease activity and physical activity on bone loss. Sixty-seven patients with non-steroid treated RA of less than 5 yr duration, including 16 patients with disease duration less than 6 months, had BMD measurements of the femoral neck and the lumbar spine over a 12-month period using dual energy X-ray absorptiometry. The BMD changes were compared with values from 72 control patients and were also correlated with serial measurements of disease activity (measured by the Stoke Index) and disability [measured by the Health Assessment Questionnaire (HAQ) score], at 3-monthly intervals over the 12-month period. No significant differences in BMD changes were found between RA patients and controls overall. Patients with disease duration of less than 6 months had significantly greater loss of BMD at the femoral neck (-3.9%, S.E.M. 1.5) than the remainder of the cohort (-0.2%, S.E.M. 0.7) (P = 0.02) and controls (-0.8%, S.E.M. 0.6). Lumbar spine BMD changes correlated with the initial Stoke Index (Rs-0.373, P = 0.01) but not mean Stoke Indices. There was no correlation of BMD changes with age or HAQ scores. These findings suggest that significant bone loss occurs within the first few months of disease in patients with RA.     

Development of an animal model for across-herd genetic evaluation of number born alive in swine

An animal model and computer software were developed to conduct across-herd genetic evaluations using data from producers participating in the Sow Productivity Index program of the American Yorkshire Club. The final data set consisted of 61,596 litter records from 1986 to early 1990. The animal model included fixed contemporary group effects and random additive direct, service sire, permanent environmental, and residual effects. Additive genetic relationships among animals were included. A separate relationship matrix for service sires and their sires was also included. A data set similar to the Yorkshire field data was simulated to use in testing the animal model. The simulated data set consisted of 40 herds, each with 120 reproducing dams and either four or five sires. Six generations of simulated data were produced, resulting in 20,605 litter records. These records were then evaluated using the animal model for number of pigs born alive. Finally, correlations between the true breeding values from the simulation and the predicted breeding values were computed. The correlation between the 918 true and predicted sire breeding values was considerably lower for the animal model without a service sire effect than when it was included (.53 vs .74, respectively). However, the difference was cut in half (.66 vs .77) when only sires with greater than five daughter records were included. The high accuracy of the animal model with a random service sire effect indicates that the proposed model adequately accounts for the variation found in records for number of pigs born alive.     

A DBR laser tunable by resistive heating

A distributed Bragg reflector (DBR) laser tuned by resistive heating is presented. It has a tuning range greater than 10 nm with only a 33% reduction in output power and a 10% increase in linewidth. Its behavior is easily modeled, agreeing well with simple theory     

George Martin Haslerud (1906–1990): Obituary.

Commemorates G. M. Haslerud, who died suddenly on April 10, 1990. In his doctoral dissertation (1934) he addressed free and prescribed maze patterns in rats, pointing to a lifetime interest in creative transfer. In 1972 he completed his magnum opus, Transfer, Memory, and Creativity: After-Learning as Perceptual Process, which reflects continuing conversations with his mentor, Robert Yerkes. Haslerud is remembered as a co-founder of the New Hampshire Psychological Association. (0 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depression in the quantity of intestinal secretory IgA and in the expression of the polymeric immunoglobulin receptor in caloric deficiency of the weanling mouse

Splenomegaly is uncommon in myelodysplasia (MDS) and, although cytopenias may be severe, therapeutic splenectomy is rarely performed. We report the histologic, histochemical, and immunophenotypic findings of nine cases of surgical splenectomy and four postmortem spleens from MDS patients. Four histologic patterns were identified: one dominated by erythrophagocytosis, one characterized by red pulp plasmacytosis, one with extramedullary hematopoiesis as the only salient finding, and one with marked red pulp expansion caused by a monocytic proliferation. Wright-Giemsa and histochemical stains were performed on touch preparations in three cases and played a critical role in the precise subclassification of one MDS patient's hematologic disorder, which ultimately proved to be chronic myelomonocytic leukemia. Splenectomy led to sustained improvement of cytopenias in three cases, but did not eliminate transfusion dependence for the remaining patients. Three splenectomy cases exhibited clustered Leder-negative mononuclear elements: two of these patients experienced disease progression to refractory anemia with excess blasts in transformation or acute myelogenous leukemia during post-splenectomy follow-up, whereas none of the three splenectomy patients without clustered mononuclear elements did. We conclude that splenomegaly in MDS usually reflects the sequelae of dyspoiesis rather than evidence of a proliferative phase, that clustering of Leder-negative large cells may correlate with either a substantial monocytic component or, possibly, increased risk of disease progression, and that the spleen can provide diagnostic as well as prognostic information in MDS patients with splenomegaly.     

ON GENERALIZED FRACTIONAL PROCESSES

Abstract. A class of stationary long-memory processes is proposed which is an extension of the fractional autoregressive moving-average (FARMA) model. The FARMA model is limited by the fact that it does not allow data with persistent cyclic (or seasonal) behavior to be considered. Our extension, which includes the FARMA model as a special case, makes use of the properties of the generating function of the Gegenbauer polynomials, and we refer to these models as Gegenbauer autoregressive moving-average (GARMA) models. While the FARMA model has a peak in the spectrum at f = 0, the GARMA process can model long-term periodic behavior for any frequency 0 f 0.5. Properties of the GARMA process are examined and techniques for generation of realizations, model identification and parameter estimation are proposed. The use of the GARMA model is illustrated through simulated examples as well as with classical sunspot data.     

IR transmission prediction,processing, and characterization of dense La2Ce2O7

High-throughput computation, based on density functional theory (HT-DFT), is used to predict the bounds for optical transparency, from the ultraviolet to the infrared, for materials in the pyrochlore family. The HT-DFT approach adopted here uses an initial screening from Materials-Project database, with millions of calculated properties. Band gaps and phonon spectra were calculated from selected pyrochlore crystal structures taken from the Materials Project database. Short and long wavelength bounds for optical transparency were calculated for chemistries with stable, cubic structures. The calculations predict that La₂Ce₂O₇ has one of the broadest range of transparency for the pyrochlore family. Based on these calculations, dense polycrystalline samples of La₂Ce₂O₇ were produced by sintering and hot-isostatic pressing. Transparency was characterized by methods that did not require large samples with high optical quality, obtaining 7.15 and 7.5 µm at 95% and 90% normalized transmittance, respectively. Bandgap calculations suggest a lower bound of UV transparency cut-off of 0.3 µm. The infrared wavelength cut-off is higher than that reported for other pyrochlores, and higher than for yttria, zirconia, or other common infrared transparent ceramics. We discuss our prediction and characterization methods as well as the suitability of pyrochlores for mid- and far-infrared optical applications.     

Evaluation and testing of a fracture critical bridge

The I-40 bridges over the Rio Grande in Albuquerque, New Mexico were due to be razed in the fall of 1993 due to geometry and traffic safety considerations, thus providing a unique opportunity for testing them. These medium span steel bridges represent a common design in the US and are classified by AASHTO as non-redundant ‘fracture critical’ two girder steel bridges (fracture critical classification means that failure of a primary member would probably cause collapse of the bridge). The subject bridge, built in 1963, is a 1275 foot (600m) bridge, and consists of three medium span continuous units with spans of 131′-163'−131′ each. The bridge was field tested to determine the impact of a near full depth girder fracture on the redistribution of loads, the load capacity, and the potential for collapse. Four levels of damage were introduced in the middle span of the north plate girder by making various cuts in the web and the flange of the girder. The final cut resulted in a six foot deep crack in the 10ft deep girder, extending from the bottom flange to the floor beam to girder connection. Data was taken under dead load and under a static live load consisting of an 82 000 lb truck. The after fracture response and the load redistribution in the fractured bridge were evaluated. The contribution of the different members to the redundancy of the structure was assessed.     

Performance evaluation of dynamic probabilistic broadcasting for flooding in mobile ad hoc networks

In mobile ad hoc networks (MANETs), flooding is a required message dissemination technique for network-wide broadcast. The conventional blind flooding algorithm causes broadcast storm problem, a high number of unnecessary packet rebroadcasts thus resulting in high contention and packet collisions. This paper proposes a new probabilistic approach that dynamically fine-tunes the rebroadcasting probability of a node for routing request packets (RREQs) according to the number of neighbour nodes. We evaluate the performance of the proposed approach for the ad hoc on demand distance vector (AODV) routing protocol and compared against the blind flooding, fixed probabilistic and adjusted probabilistic flooding [L.M.M.M. Bani-Yassein, M. Ould-Khaoua et al., Performance analysis of adjusted probabilistic broadcasting in mobile ad hoc networks, International Journal of Wireless Information Networks 13(2) (2006) 127–140; M.B. Yassein, M.O. Khaoua et al., Improving route discovery in on-demand routing protocols using local topology information in MANETs, Proceedings of the ACM international workshop on Performance Monitoring, Measurement, and Evaluation of Heterogeneous Wireless and Wired Networks, Terromolinos, Spain, ACM Press, 2006, pp. 95–99.] approaches. The simulation results show that our proposed approach demonstrates better performance than blind flooding, fixed probabilistic and adjusted flooding approaches.