Faddeev approach to confined three-quark problems

We propose a method that allows for the efficient solution of the three-body Faddeev equations in the presence of infinitely rising confinement interactions. Such a method is useful in calculations of nonrelativistic and especially semirelativistic constituent quark models. The convergence of the partial wave series is accelerated and possible spurious contributions in the Faddeev components are avoided. We demonstrate how the method works with the example of the Goldstone-boson-exchange chiral quark model for baryons.Comment: 6 page

Difference of high-light stress sensitivity in the two firs, Abies mariesii and Abies veitchii, in early spring

Abies veitchii and Abies mariesii are dominant species at the tree-line in Central Japan. Recently, we observed needle death, probably due to photodamage of the photosynthetic apparatus at the tree-limit during March-April. A. veitchii survives winter without any needle death due to photodamage at the tree-line. However, there is no conspicuous damage between the two species because this phenomenon is only observed at the tree-limit. In this study, we examined the difference in winter down-regulation of PS II between A. veitchii and A. mariesii and observed the following results: In March, (1) Fv/Fm of both species was about 0.1, showing the photochemical efficiency being severely inhibited. (2) The de-epoxidation state, expressed as [(A+Z)/(V+A+Z)], was about 0.35 for both species. (3) Chlorophyll (Chl) content of A. veitchii was much less than that of A. mariesii and Pchlide was found only in A. veitchii. In April, (1) Fv/Fm increased and [(A+Z)/(V+A+Z)] decreased for both species. (2) Chl content of A. veitchii increased by four-fold while Pchlide nearly dissappeared. These results indicate the following: During cold periods, most of Chl of A. veitchii may have been converted to Pchlide which is easily re-converted to Chl in spring, an intermediate of Chl biosynthesis. Winter conversion from Chl to Pchlide in A. veitchii may provide effective protection from photodamage of the photosynthetic apparatus. Furthermore, this may explain the higher ability of A. veitchii to prevent photodamage compared to A. mariesii

The YlmG protein has a conserved function related to the distribution of nucleoids in chloroplasts and cyanobacteria

<p>Abstract</p> <p>Background</p> <p>Reminiscent of their free-living cyanobacterial ancestor, chloroplasts proliferate by division coupled with the partition of nucleoids (DNA-protein complexes). Division of the chloroplast envelope membrane is performed by constriction of the ring structures at the division site. During division, nucleoids also change their shape and are distributed essentially equally to the daughter chloroplasts. Although several components of the envelope division machinery have been identified and characterized, little is known about the molecular components/mechanisms underlying the change of the nucleoid structure.</p> <p>Results</p> <p>In order to identify new factors that are involved in the chloroplast division, we isolated <it>Arabidopsis thaliana </it>chloroplast division mutants from a pool of random cDNA-overexpressed lines. We found that the overexpression of a previously uncharacterized gene (<it>AtYLMG1-1</it>) of cyanobacterial origin results in the formation of an irregular network of chloroplast nucleoids, along with a defect in chloroplast division. In contrast, knockdown of <it>AtYLMG1-1 </it>resulted in a concentration of the nucleoids into a few large structures, but did not affect chloroplast division. Immunofluorescence microscopy showed that AtYLMG1-1 localizes in small puncta on thylakoid membranes, to which a subset of nucleoids colocalize. In addition, in the cyanobacterium <it>Synechococcus elongates</it>, overexpression and deletion of <it>ylmG </it>also displayed defects in nucleoid structure and cell division.</p> <p>Conclusions</p> <p>These results suggest that the proper distribution of nucleoids requires the YlmG protein, and the mechanism is conserved between cyanobacteria and chloroplasts. Given that <it>ylmG </it>exists in a cell division gene cluster downstream of <it>ftsZ </it>in gram-positive bacteria and that <it>ylmG </it>overexpression impaired the chloroplast division, the nucleoid partitioning by YlmG might be related to chloroplast and cyanobacterial division processes.</p

Patients with CDH23 mutations and the 1555A > G mitochondrial mutation are good candidates for electric acoustic stimulation (EAS)

Conclusions: CDH23 mutations and the 1555A>G mitochondrial mutation were identified among our series of electric acoustic stimulation (EAS) patients, confirming that these genes were important in hearing loss with involvement of high frequency. Successful hearing preservation as well as good outcomes from EAS indicated that patients with this combination of mutations are good candidates for EAS. Objectives: Screening for gene mutations that possibly cause hearing loss involving high frequency was performed to identify the responsible genes in patients with EAS. In addition to a review of the genetic background of the patients with residual hearing loss, the benefit of EAS for patients with particular gene mutations was evaluated. Methods: Eighteen patients (15 late-onset, 3 early-onset) with residual hearing who had received EAS were included in this study. Genetic analysis was performed to identify GJB2, CDH23, SLC26A4, and the 1555 mitochondrial mutations. Results: Three early-onset patients had CDH23 mutations. One late-onset patient had the 1555 A>G mitochondrial mutation.ArticleACTA OTO-LARYNGOLOGICA. 132(4):377-384 (2012)journal articl

Achievement of hearing preservation in the presence of an electrode covering the residual hearing region

Conclusions: With full insertion with a long electrode, hearing preservation can be achieved even in the presence of a long electrode covering the residual hearing region. Objectives: Advances in developing new atraumatic concepts of electrode design as well as surgical technique have enabled hearing preservation after cochlear implantation surgery, and EAS (electric acoustic stimulation) accompanied with hearing preservation is a new trend for patients with residual hearing at the lower frequencies. However, full insertion with a long/medium electrode and hearing preservation is still a challenging field that calls for discussion. Method: In this study, round window insertion, an atraumatic electrode, and dexamethasone administration were used and atraumaticity (hearing preservation and conservation of vestibular function) was evaluated with full insertion of the electrode. Results: Postoperative evaluation after full insertion of the electrodes showed that hearing at low frequencies was well preserved in all five cases. Combined postoperative imaging with the referential tonotopic map confirmed achievement of full insertion and indicated the corresponding frequencies and the depth of the electrode. Achievement of atraumaticity of round window insertion in the present cases was confirmed from the viewpoint of the minimal drilling time as well as the preserved vestibular function.ArticleACTA OTO-LARYNGOLOGICA. 131(4):405-412 (2011)journal articl

Pulsar kicks from neutrino oscillations

Neutrino oscillations in a core-collapse supernova may be responsible for the observed rapid motions of pulsars. Given the present bounds on the neutrino masses, the pulsar kicks require a sterile neutrino with mass 2-20 keV and a small mixing with active neutrinos. The same particle can be the cosmological dark matter. Its existence can be confirmed the by the X-ray telescopes if they detect a 1-10 keV photon line from the decays of the relic sterile neutrinos. In addition, one may be able to detect gravity waves from a pulsar being accelerated by neutrinos in the event of a nearby supernova.Comment: invited review article to appear in Int. J. Mod. Phys. (21 pages, 6 figures

Alternative splicing produces structural and functional changes in CUGBP2

<p>Abstract</p> <p>Background</p> <p>CELF/Bruno-like proteins play multiple roles, including the regulation of alternative splicing and translation. These RNA-binding proteins contain two RNA recognition motif (RRM) domains at the N-terminus and another RRM at the C-terminus. CUGBP2 is a member of this family of proteins that possesses several alternatively spliced exons.</p> <p>Results</p> <p>The present study investigated the expression of exon 14, which is an alternatively spliced exon and encodes the first half of the third RRM of CUGBP2. The ratio of exon 14 skipping product (<it>R3δ</it>) to its inclusion was reduced in neuronal cells induced from P19 cells and in the brain. Although full length CUGBP2 and the CUGBP2 <it>R3δ </it>isoforms showed a similar effect on the inclusion of the smooth muscle (SM) exon of the <it>ACTN1 </it>gene, these isoforms showed an opposite effect on the skipping of exon 11 in the <it>insulin receptor </it>gene. In addition, examination of structural changes in these isoforms by molecular dynamics simulation and NMR spectrometry suggested that the third RRM of R3δ isoform was flexible and did not form an RRM structure.</p> <p>Conclusion</p> <p>Our results suggest that CUGBP2 regulates the splicing of <it>ACTN1 </it>and <it>insulin receptor </it>by different mechanisms. Alternative splicing of <it>CUGBP2 </it>exon 14 contributes to the regulation of the splicing of the <it>insulin receptor</it>. The present findings specifically show how alternative splicing events that result in three-dimensional structural changes in CUGBP2 can lead to changes in its biological activity.</p