Ferromagnetic one dimensional Ti atomic chain

Using the full potential linearized augmented plane wave (FLAPW) method, we have explored the magnetic properties of one dimensional (1D) Ti atomic chain. Astonishingly, we for the first time observed that the 1D Ti atomic chain has ferromagnetic ground state even on NiAl(110) surface although the Ti has no magnetic moment in bulk or macroscopic state. It was found that the physical property of direct exchange interaction among Ti atoms occurred in free standing state is well preserved on NiAl(110) surface and this feature has an essential role in ferromagnetism of 1D Ti atomic chain. It was shown that the m=$|2|$ state has the largest contribution to the magnetic moment of Ti atom grown on NiAl(110) surface. In addition, we found that the magnetic dipole interaction is a key factor in the study of magnetic anisotropy, not the magnetocrystalline anisotropy arising from spin-orbit interaction

Molecular Mechanisms of Sleep/Wake Regulation and Memory Formation in Young and Aged Mice

Advancements in healthcare and medicine have greatly increased lifespan. Normal aging is accompanied by deterioration of key physiological processes, including sleep and cognition. Understanding the mechanisms by which these functions go awry with age is a critical step in identifying novel therapeutic strategies to improve quality of life for the elderly. One of the most prevalent complaints in the elderly is the deterioration of sleep/wake patterns, difficulties staying awake and reduced vigilance. Little is known about the molecular mechanisms controlling these states in the brain. Mouse models are ideally suited to address this question because they share many similarities with human biology and afford the ability to manipulate molecular pathways in vivo. In Chapter 2, we use polysomnography and conditional mutant animals to explore the molecular underpinnings involved in the maintenance of wakefulness. Our results indicate that the activity-dependent transcription factor cAMP response element binding protein (CREB) is critical in forebrain neurons for the maintenance of wakefulness. Interestingly, aging also reduces the ability to sustain wakefulness in the elderly. In Chapter 3, we use polysomnography in young and aged mice, combined with a novel statistical approach to closely examine how aging impacts the microstructure of sleep and wakefulness. We show that aging specifically impairs the ability to sustain long episodes of wake and non-rapid eye movement (NREM) sleep. Another major health concern for older individuals is the decline of cognitive function. In Chapter 4, we use object-based memory paradigms to investigate memory formation in aged mice. Object-based tasks are ideally suited for these studies because they circumvent the confounding alterations in motor function and stress response that accompany aging. We show that aging impairs the consolidation of memories related to the location of objects in space. Our findings indicate that the hippocampus, a brain region critical to spatial memory, is particularly vulnerable to aging. Taken together, our findings outline the molecular pathways involved in the regulation of sleep and wake and lay the groundwork for further understanding of how these systems are altered in the aged brain

Fibroblast growth factor receptor 4 single nucleotide polymorphism Gly388Arg in head and neck carcinomas

BACKGROUND Head and neck squamous cell carcinoma (HNSCC) is considered to be a progressive disease resulting from alterations in multiple genes regulating cell proliferation and differentiation like receptor tyrosine kinases (RTKs) and members of the fibroblast growth factor receptors (FGFR)-family. Single-nucleotide polymorphism (SNP) Arg388 of the FGFR4 is associated with a reduced overall survival in patients with cancers of various types. We speculate that FGFR4 expression and SNP is associated with worse survival in patients with HSNCC. AIM To investigate the potential clinical significance of FGFR4 Arg388 in the context of tumors arising in HNSCC, a comprehensive analysis of FGFR4 receptor expression and genotype in tumor tissues and correlated results with patients' clinical data in a large cohort of patients with HNSCC was conducted. METHODS Surgical specimens from 284 patients with HNSCC were retrieved from the Institute of Pathology at the Ludwig-Maximilian-University in Germany. Specimens were analyzed using immunohistochemistry and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The expression of FGFR4 was analyzed in 284 surgical specimens of HNSCC using immunohistochemstry. FGFR4 polymorphism was detected by PCR-RFLP. Patients' clinical data with a minimum follow-up of 5 syears were statistically evaluated with a special emphasis on survival analysis employing Kaplan-Meier estimator and Cox regression analysis. RESULTS Concerning the invasive tumor areas the intensity of the FGFR4 expression was evaluated in a four-grade system: no expression, low expression, intermediate and high expression. FGFR4 expression was scored as "high" (+++) in 74 (26%), "intermediate" (++) in 103 (36.3%), and "low" (+) in 107 (36.7%) cases. Analyzing the FGFR4 mutation it was found in 96 tumors (33.8%), 84 of them (29.6%) having a heterozygous and 12 (4.2%) homozygous mutated Arg388 allele. The overall frequency concerning the mutant alleles demonstrated 65% vs 34% mutated alleles in general. FGFR4 Arg388 was significantly associated with advanced tumor stage (P < 0.004), local metastasis (P < 0.0001) and reduced disease-free survival (P < 0.01). Furthermore, increased expression of FGFR4 correlated significantly with worse overall survival (P < 0.003). CONCLUSION In conclusion, the FGFR4 Arg388 genotype and protein expression of FGFR4 impacts tumor progression in patients with HNSCC and may present a useful target within a multimodal therapeutic intervention

Improved silicon nitride for advanced heat engines

The AiResearch Casting Company baseline silicon nitride (92 percent GTE SN-502 Si sub 3 N sub 4 plus 6 percent Y sub 2 O sub 3 plus 2 percent Al sub 2 O sub 3) was characterized with methods that included chemical analysis, oxygen content determination, electrophoresis, particle size distribution analysis, surface area determination, and analysis of the degree of agglomeration and maximum particle size of elutriated powder. Test bars were injection molded and processed through sintering at 0.68 MPa (100 psi) of nitrogen. The as-sintered test bars were evaluated by X-ray phase analysis, room and elevated temperature modulus of rupture strength, Weibull modulus, stress rupture, strength after oxidation, fracture origins, microstructure, and density from quantities of samples sufficiently large to generate statistically valid results. A series of small test matrices were conducted to study the effects and interactions of processing parameters which included raw materials, binder systems, binder removal cycles, injection molding temperatures, particle size distribution, sintering additives, and sintering cycle parameters

Remarks on monopole charge properties within the Generalized Coherent State Model

The Generalized Coherent State Model, proposed previously for a unified description of magnetic and electric collective properties of nuclear systems, is used to study the ground state band charge density as well as the E0 transitions from $0^+_{\beta}$ to $0^+_g$. The influence of the nuclear deformation and of angular momentum projection on the charge density is investigated. The monopole transition amplitude has been calculated for ten nuclei. The results are compared with some previous theoretical studies and with the available experimental data. Our results concerning angular momentum projection are consistent with those of previous microscopic calculations for the ground state density. The calculations for the E0 transitions agree quite well with the experimental data. Issues like how the shape transitions or shape coexistence are reflected in the $\rho(E0)$ behavior are also addressed.Comment: 32 pages, 7 figure

Boundary Terms in Supergravity and Supersymmetry

We begin with the simplest possible introduction to supergravity. Then we discuss its spin 3/2 stress tensor; these results are new. Next, we discuss boundary conditions on fields and boundary actions for N=1 supergravity. Finally, we discuss new boundary contributions to the mass and central charge of monopoles in N=4 super Yang-Mills theory. All models are in 3+1 dimensions.Comment: 15 pages. Talk given by P. van Nieuwenhuizen at the Einstein-celebration gravitational conference at Puri (India) in December 200

Children's working understanding of knowledge sources : confidence in knowledge gained from testimony

In three experiments children aged between 3 and 5 years (N = 38; 52; 94; mean ages 3;7 to 5;2) indicated their confidence in their knowledge of the identity of a hidden toy. With the exception of some 3-year-olds, children revealed working understanding of their knowledge source by showing high confidence when they had seen or felt the toy, and lower confidence when they had been told its identity by an apparently well-informed speaker, especially when the speaker subsequently doubted the adequacy of his access to the toy. After a 2-minute delay, 3-to 4- year olds, unlike 4- to 5-year-olds, failed to see the implications of the speaker’s doubt about his access