Centrally symmetric configurations of order polytopes

It is shown that the toric ideal of the centrally symmetric configuration of the order polytope of a finite partially ordered set possesses a squarefree quadratic initial ideal. It then follows that the convex polytope arising from the centrally symmetric configuration of an order polytope is a normal Gorenstein Fano polytope.Comment: 9 pages, Proof of Theorem 2.2 is simplified. Major revision on Section

Self-modulation of nonlinear light in vacuum enhanced by orbital angular momentum

Nonlinear optical effects in vacuum have been investigated as a means to verify quantum electrodynamics in a region of low photon energy. By considering nonlinear electromagnetic waves in a three-dimensional cylindrical cavity, we report that the orbital angular momentum of light strongly affects self-modulations in a long timescale. The variation in optical phase is shown to enhance the vacuum nonlinearity. Moreover, we demonstrate the time evolution of the energy transfer between cavity modes and of the phase shift, paving new possibility for verification experiments

The identification and functional implications of human-specific "fixed" amino acid substitutions in the glutamate receptor family

<p>Abstract</p> <p>Background</p> <p>The glutamate receptors (GluRs) play a vital role in the mediation of excitatory synaptic transmission in the central nervous system. To clarify the evolutionary dynamics and mechanisms of the GluR genes in the lineage leading to humans, we determined the complete sequences of the coding regions and splice sites of 26 chimpanzee GluR genes.</p> <p>Results</p> <p>We found that all of the reading frames and splice sites of these genes reported in humans were completely conserved in chimpanzees, suggesting that there were no gross structural changes in humans after their divergence from the human-chimpanzee common ancestor. We observed low <it>K</it>_<it>A</it>/<it>K</it>_{<it>S </it>}ratios in both humans and chimpanzees, and we found no evidence of accelerated evolution. We identified 30 human-specific "fixed" amino acid substitutions in the GluR genes by analyzing 80 human samples of seven different populations worldwide. Grantham's distance analysis showed that <it>GRIN2C </it>and <it>GRIN3A </it>are the most and the second most diverged GluR genes between humans and chimpanzees. However, most of the substitutions are non-radical and are not clustered in any particular region. Protein motif analysis assigned 11 out of these 30 substitutions to functional regions. Two out of these 11 substitutions, D71G in <it>GRIN3A </it>and R727H in <it>GRIN3B</it>, caused differences in the functional assignments of these genes between humans and other apes.</p> <p>Conclusion</p> <p>We conclude that the GluR genes did not undergo drastic changes such as accelerated evolution in the human lineage after the divergence of chimpanzees. However, there remains a possibility that two human-specific "fixed" amino acid substitutions, D71G in <it>GRIN3A </it>and R727H in <it>GRIN3B</it>, are related to human-specific brain function.</p

Multiple Myeloma Presenting Symptoms in the Oral and Maxillofacial Region

Four cases of multiple myeloma presenting symptoms in the oral and maxillofacial region are reported. The main complaints in 2 patients were macroglossia and dysphagia. We doubted these cases were amyloidosis, but examinations performed for possible amyloidosis led us to a diagnosis of multiple myeloma. The other 2 patients presented signs in the mandible. One of them had a mass-type lesion in the gingiva which upon X-ray revealed an osteolytic lesion in the mandible and multiple "punched-out" osteolytic lesions in the cranial bones. The other showed only a diffuse non-homogeneous radiolucent lesion and dental ankylosis. Medical history and biochemical and hematologic findings would be helpful in diagnosing multiple myeloma. Here, we report our summarization of these 4 cases

Source-Frequency Phase-Referencing Observation of AGNs with KaVA Using Simultaneous Dual-Frequency Receiving

The KVN(Korean VLBI Network)-style simultaneous multi-frequency receiving mode is demonstrated to be promising for mm-VLBI observations. Recently, other Very long baseline interferometry (VLBI) facilities all over the globe start to implement compatible optics systems. Simultaneous dual/multi-frequency VLBI observations at mm wavelengths with international baselines are thus possible. In this paper, we present the results from the first successful simultaneous 22/43 GHz dual-frequency observation with KaVA(KVN and VERA array), including images and astrometric results. Our analysis shows that the newly implemented simultaneous receiving system has brought a significant extension of the coherence time of the 43 GHz visibility phases along the international baselines. The astrometric results obtained with KaVA are consistent with those obtained with the independent analysis of the KVN data. Our results thus confirm the good performance of the simultaneous receiving systems for the non-KVN stations. Future simultaneous observations with more global stations bring even higher sensitivity and micro-arcsecond level astrometric measurements of the targets.Comment: 8 pages, 6 figures, Published in JKA