A TEM study on the microstructure of spark plasma sintered ZrB_2-based composite with nano-sized SiC dopant

Sintering behavior of ZrB_2 ceramic with nano-sized SiC dopant was studied. ZrB_2-25 vol% nano-sized SiC was selected as the starting mixture to fabricate the composite. The manufacturing process was accomplished at 1800℃ for 5 min under 25 MPa via spark plasma sintering(SPS). The as-sintered sample reached a relative density of 99%. Besides the initial phases, namely ZrB_2 and SiC, the high-resolution X-ray diffraction(HRXRD) was used to study the formation of an in-situ ZrC phase. The possible chemical interactions during the ZrC phase formation were scrutinized. The microstructure of the composite was studied by the field emission scanning electron microscopy(FESEM) and transmission electron microscopy(TEM). Elemental analysis through FESEM evaluations revealed the formation of amorphous phases, rich in Zr, C, Si, B, and O elements, which was in harmony with the thermodynamical assessments. TEM studies endorsed the formation of such phases, containing a glassy bed of Si–B–O with ZrC and C islands dispersed therein.     

Pragmatism, Realism and Hermeneutics

This paper explores themethodological consequences of AmericanPragmatism for the social sciences. It alsocriticises some rival perspectives onmethodology of social research, in particularfalsificationist, realist and someanti-naturalist views. It is argued thatAmerican Pragmatism shows striking affinitieswith the genealogical method of history and thereflexive turn in cultural anthropology. It isalso argued that Pragmatism forces us to thinkdifferently about the relationship betweentheory and empirical research.     

Stepwise replication identifies a low-producing lymphotoxin-alpha allele as a major risk factor for early-onset leprosy

Host genetics has an important role in leprosy, and variants in the shared promoter region of PARK2 and PACRG were the first major susceptibility factors identified by positional cloning. Here we report the linkage disequilibrium mapping of the second linkage peak of our previous genome-wide scan, located close to the HLA complex. In both a Vietnamese familial sample and an Indian case-control sample, the low-producing lymphotoxin-alpha (LTA)+80 A allele was significantly associated with an increase in leprosy risk (P = 0.007 and P = 0.01, respectively). Analysis of an additional case-control sample from Brazil and an additional familial sample from Vietnam showed that the LTA+80 effect was much stronger in young individuals. In the combined sample of 298 Vietnamese familial trios, the odds ratio of leprosy for LTA+80 AA/AC versus CC subjects was 2.11 (P = 0.000024), which increased to 5.63 (P = 0.0000004) in the subsample of 121 trios of affected individuals diagnosed before 16 years of age. In addition to identifying LTA as a major gene associated with early-onset leprosy, our study highlights the critical role of case- and population-specific factors in the dissection of susceptibility variants in complex diseases.     

The neuronal sortilin-related receptor SORL1 is genetically associated with Alzheimer disease

The recycling of the amyloid precursor protein (APP) from the cell surface via the endocytic pathways plays a key role in the generation of amyloid beta peptide (Abeta) in Alzheimer disease. We report here that inherited variants in the SORL1 neuronal sorting receptor are associated with late-onset Alzheimer disease. These variants, which occur in at least two different clusters of intronic sequences within the SORL1 gene (also known as LR11 or SORLA) may regulate tissue-specific expression of SORL1. We also show that SORL1 directs trafficking of APP into recycling pathways and that when SORL1 is underexpressed, APP is sorted into Abeta-generating compartments. These data suggest that inherited or acquired changes in SORL1 expression or function are mechanistically involved in causing Alzheimer disease.     

Non-Minimum Phase Nonlinear System Predictive Control Based on Local Recurrent Neural Networks

Abstract: After a recursive multi-step-ahead predictor for nonlinear systems based on local recurrent neural networks isintroduced, an intelligent PID controller is adopted to correct the errors including identified model errors and accumulatederrors produced in the recursive process. Characterized by predictive control, this method can achieve a good controlaccuracy and has good robustness. A simulation study shows that this control algorithm is very effective.     

Chromosomal localization of a unique gene by non-autoradiographic in situ hybridization

During the past few years, several methods have been developed for the detection of specific nucleic acid sequences by in situ hybridization using non-radioactive labels such as fluorochromes, cytochemically detectable enzymes and electron-dense markers. These methods are preferable to autoradiography in terms of speed of performance and topological resolution. Their limited sensitivity, however, has so far restricted their use to the detection of repeated sequences. Here we report single gene detection with a procedure using 2-acetylaminofluorene (AAF)-modified probes, immunoperoxidase cytochemistry and reflection-contrast microscopy. We confirmed the autoradiographic data on the localization of the human thyroglobulin (Tg) gene to the distal end of the long arm of chromosome 8. A mixture of cosmid cHT2-derived subclones of the 3' part of the Tg gene, 22.3 kilobase pairs (kbp) in total, was used as a hybridization probe. This procedure can be used to map other unique sequences, if genomic clones are available from which clones with an appropriate amount of inserts can be isolated.     

Inheritance and expression ofEsterase-1 allozymes inPeromyscus leucopus

Summary We analyzed inheritance of 5Es-1 alleles inP. leucopus and found them to be co-dominant and segregating from a single autosomal locus, thereby verifying assumptions of Mendelian inheritance imfield data. We also described an allele that is silent in hemolysate, but is active in liver extract.Acknowledgment. Laboratory analysis was partially supported by a grant-in-aid (No. 0171-02-240-76) to Kaufman from the Research Foundation of State University of New York.