Probing quark-gluon interactions with transverse polarized scattering

We have extracted QCD matrix elements from our data on doubly polarized inelastic scattering of electrons on nuclei. We find the higher twist matrix element d˜2, which arises strictly from quark-gluon interactions, to be unambiguously nonzero. The data also reveal an isospin dependence of higher twist effects if we assume that the Burkhardt-Cottingham sum rule is valid. The fundamental Bjorken sum rule obtained from the a0 matrix element is satisfied at our low momentum transfer.

Size of the largest lymph node visualized on multi-detector-row computed tomography (MDCT) is useful in predicting metastatic lymph node status of gastric cancer

This study was designed to investigate whether the size of the largest lymph node (long-axis diameter [LAD] and short-axis diameter [SAD]) visualized using multi-detector-row computed tomography (MDCT) was useful for predicting the metastatic lymph node (MLN) status of gastric cancer. A retrospective analysis of 305 gastric cancer patients who underwent pre-operative MDCT was performed, followed by a prospective study in 61 gastric cancer patients to determine the diagnostic effectiveness of LAD and SAD. In the retrospective study, the accuracy of LAD and SAD for predicting the MLN status of gastric cancer was 51.1% and 45.9%, respectively. In the prospective study, the accuracy of LAD and SAD measurement and the traditional MDCT method of counting MLNs was 52.5%, 49.2% and 57.4%, respectively; the differences were not significant. In conclusion, the size of the largest lymph node in terms of LAD and SAD visualized on MDCT was useful for predicting the MLN status of gastric cancer, with accuracy comparable to the traditional MDCT method of counting the total number of MLNs detected.

A pseudoinverse deformation vector field generator and its applications

PURPOSE

To present, implement, and test a self-consistent pseudoinverse displacement vector field (PIDVF) generator, which preserves the location of information mapped back-and-forth between image sets.

METHODS

The algorithm is an iterative scheme based on nearest neighbor interpolation and a subsequent iterative search. Performance of the algorithm is benchmarked using a lung 4DCT data set with six CT images from different breathing phases and eight CT images for a single prostrate patient acquired on different days. A diffeomorphic deformable image registration is used to validate our PIDVFs. Additionally, the PIDVF is used to measure the self-consistency of two nondiffeomorphic algorithms which do not use a self-consistency constraint: The ITK Demons algorithm for the lung patient images and an in-house B-Spline algorithm for the prostate patient images. Both Demons and B-Spline have been QAed through contour comparison. Self-consistency is determined by using a DIR to generate a displacement vector field (DVF) between reference image R and study image S (DVF(R-S)). The same DIR is used to generate DVF(S-R). Additionally, our PIDVF generator is used to create PIDVF(S-R). Back-and-forth mapping of a set of points (used as surrogates of contours) using DVF(R-S) and DVF(S-R) is compared to back-and-forth mapping performed with DVF(R-S) and PIDVF(S-R). The Euclidean distances between the original unmapped points and the mapped points are used as a self-consistency measure.

RESULTS

Test results demonstrate that the consistency error observed in back-and-forth mappings can be reduced two to nine times in point mapping and 1.5 to three times in dose mapping when the PIDVF is used in place of the B-Spline algorithm. These self-consistency improvements are not affected by the exchanging of R and S. It is also demonstrated that differences between DVF(S-R) and PIDVF(S-R) can be used as a criteria to check the quality of the DVF.

CONCLUSIONS

Use of DVF and its PIDVF will improve the self-consistency of points, contour, and dose mappings in image guided adaptive therapy.

Factors associated with bed and room sharing in Chinese school-aged children

BACKGROUND AND OBJECTIVES

Co-sleeping (bed or room sharing) has potential implications for children's development. Previous studies showed that co-sleeping was more prevalent in non-Western countries than in Western countries, which demonstrated that co-sleeping was marked with ethnic and socio-cultural background characteristics. The purpose of this study was to survey the prevalence of bed and room sharing and to examine related factors among school-aged children in an Asian country - China.

METHODS

A cross-sectional questionnaire survey was conducted in 10 districts of Shanghai, China from November to December 2005. A total of 4108 elementary school children, 49.2% boys and 50.8% girls with a mean age of 8.79 years, participated. Parent-administered questionnaires were used to collect information about children's sleeping arrangements and socio-demographic characteristics.

RESULTS

The prevalence of routine bed sharing, room sharing and sleeping alone in Chinese school-aged children was 21.0%, 19.1% and 47.7%, respectively. Bed and room sharing didn't show significant gender difference but gradually decreased with increasing age. Multivariate logistic regression identified those factors associated with bed and room sharing: younger age, large family, children without their own bedroom and parents' approval of a co-sleeping arrangement.

CONCLUSION

Co-sleeping arrangement was a common practice in Chinese school-aged children. Associated factors were characterized by intrinsic socio-cultural values and socio-economic status in China.

Analysis and location of a rice BAC clone containing telomeric DNA sequences

BAC2, a rice BAC clone containing (TTTAGGG)(n) homologous sequences, was analyzed by Southern hybridization and DNA sequencing of its subclones. It was disclosed that there were many tandem repeated satellite DNA sequences, called TA352, as well as simple tandem repeats consisting of TTTAGGG or its variant within the BAC2 insert. A 0. 8 kb (TTTAGGG)(n)-containing fragment in BAC2 was mapped in the telomere regions of at least 5 pairs of rice chromosomes by using fluorescencein situ hybridization (FISH). By RFLP analysis of low copy sequences the BAC2 clone was localized in one terminal region of chromosome 6. All the results strongly suggest that the telomeric DNA sequences of rice are TTTAGGG or its variant, and the linked satellite DNA TA352 sequences belong to telomere-associated sequences.

Controlled release of an antibiotic, gentamicin sulphate, from gravity spun polycaprolactone fibers

The antibiotic, gentamicin sulphate (GS), was incorporated in gravity-spun polycaprolactone (PCL) fibers by spinning from particulate suspensions of the drug in PCL solution to produce a controlled delivery system. The production rate of GS-loaded PCL fibers was confined to the range 1-1.5 m/min and the fiber diameter to 170-220 microm. The kinetics of drug release could be adjusted by varying the GS loading of the fibers and the suspension preparation conditions. Gradual release of approximately 80% of the initial GS content was measured in phosphate buffered saline at 37 degrees C over 50 days from fibers spun from nonhomogenized suspensions, whereas loss of this amount of antibiotic occurred in less than 10 days from fibers spun from homogenized suspensions. Studies of growth inhibition of Stapyhlococcus epidermidis in culture indicated that GS released after 2 weeks from PCL fibers retained antibacterial activity. This behavior recommends further investigation of PCL fibers for local delivery of antibiotics to combat infection associated with periodontal disease, musculoskeletal injuries, and implantation of fiber-based tissue substitutes such as vascular prostheses.

Discrimination of outer membrane proteins using a K-nearest neighbor method

Identification of outer membrane proteins (OMPs) from genome is an important task. This paper presents a k-nearest neighbor (K-NN) method for discriminating outer membrane proteins (OMPs). The method makes predictions based on a weighted Euclidean distance that is computed from residue composition. The method achieves 89.1% accuracy with 0.668 MCC (Matthews correlation coefficient) in discriminating OMPs and non-OMPs. The performance of the method is improved by including homologous information into the calculation of residue composition. The final method achieves an accuracy of 96.1%, with 0.873 MCC, 87.5% sensitivity, and 98.2% specificity. Comparisons with multiple recently published methods show that the method proposed in this study outperforms the others.

Variants in the 5q31 cytokine gene cluster are associated with psoriasis

A multitiered genetic association study of 25 215 single-nucleotide polymorphisms (SNPs) in three case-control sample sets (1446 patients and 1432 controls) identified three IL13-linked SNPs (rs1800925, rs20541 and rs848) associated with psoriasis. Although the susceptibility effects at these SNPs were modest (joint allelic odds ratios (ORs): 0.76 to 0.78; P(comb): 1.3E-03 to 2.50E-04), the association patterns were consistent across the sample sets, with the minor alleles being protective. Haplotype analyses identified one common, susceptible haplotype CCG (joint allelic OR=1.27; P(comb)=1.88E-04) and a less common, protective haplotype TTT (joint allelic OR=0.74; P(comb)=7.05E-04). In combination with the other known genetic risk factors, HLA-C, IL12B and IL23R, the variants reported here generate an 11-fold psoriasis-risk differential. Residing in the 5q31 cytokine gene cluster, IL13 encodes an important T-cell-derived cytokine that regulates cell-mediated immunity. These results provide the foundation for additional studies required to fully dissect the associations within this cytokine-rich genomic region, as polymorphisms in closely linked candidate genes, such as IRF1, IL5 or IL4, may be driving these results through linkage disequilibrium.