A Simultaneous Solution to the ^6Li and ^7Li Big Bang Nucleosynthesis Problems from a Long-Lived Negatively-Charged Leptonic Particle

The $^6$Li abundance observed in metal poor halo stars exhibits a plateau similar to that for $^7$Li suggesting a primordial origin. However, the observed abundance of $^6$Li is a factor of $10^3$ larger and that of $^7$Li is a factor of 3 lower than the abundances predicted in the standard big bang when the baryon-to-photon ratio is fixed by WMAP. Here we show that both of these abundance anomalies can be explained by the existence of a long-lived massive, negatively-charged leptonic particle during nucleosynthesis. Such particles would capture onto the synthesized nuclei thereby reducing the reaction Coulomb barriers and opening new transfer reaction possibilities, and catalyzing a second round of big bang nucleosynthesis. This novel solution to both of the Li problems can be achieved with or without the additional effects of stellar destruction.Comment: 6 pages, 2 figures, to be published in Physical Review

Severe Facet Joint Arthrosis Caused C7/T1 Myelopathy: A Case Report

Cervical myelopathy is caused by degenerative processes of the spine including intervertebral disc herniation and posterior spur usually developing at C3/4 to C5/6. C7/T1 single level myelopathy is very rare because of the anatomical characteristics. Facet joint arthrosis can be a cause of cervical myelopathy but only a few cases have been reported. The authors report an extremely rare case of C7/T1 myelopathy caused by facet joint arthrosis. A 58-year-old male presented with hand and gait clumsiness. The radiological examinations revealed severe C7/T1 facet joint arthrosis with bony spur extending into the spinal canal, which compressed the spinal cord laterally. The T1 spinous process indicated nonunion of a “clay-shoveler's” fracture, which suggested that his cervico-thoracic spine had been frequently moved, and thus severe arthrosis had occurred in the facet joints. A right hemilaminectomy of C7 and C7/T1 facetectomy with single level spinal fusion led to complete neurological improvement

New Constraints on Radiative Decay of Long-Lived Particles in Big Bang Nucleosynthesis with New 4^4He Photodisintegration Data

A recent measurement of $^4$He photodisintegration reactions, $^4$He($\gamma$,$p$)$^3$H and $^4$He($\gamma$,$n$)$^3$He with laser-Compton photons shows smaller cross sections than those estimated by other previous experiments at $E_\gamma \lesssim 30$ MeV. We study big-bang nucleosynthesis with the radiative particle decay using the new photodisintegration cross sections of $^4$He as well as previous data. The sensitivity of the yields of all light elements D, T, $^3$He, $^4$He, $^6$Li, $^7$Li and $^7$Be to the cross sections is investigated. The change of the cross sections has an influence on the non-thermal yields of D, $^3$He and $^4$He. On the other hand, the non-thermal $^6$Li production is not sensitive to the change of the cross sections at this low energy, since the non-thermal secondary synthesis of $^6$Li needs energetic photons of $E_\gamma \gtrsim 50$ MeV. The non-thermal nucleosynthesis triggered by the radiative particle decay is one of candidates of the production mechanism of $^6$Li observed in metal-poor halo stars (MPHSs). In the parameter region of the radiative particle lifetime and the emitted photon energy which satisfies the $^6$Li production above the abundance level observed in MPHSs, the change of the photodisintegration cross sections at $E_\gamma \lesssim 30$ MeV as measured in the recent experiment leads to $\sim 10$% reduction of resulting $^3$He abundance, whereas the $^6$Li abundance does not change for this change of the cross sections of $^4$He($\gamma$,$p$)$^3$H and $^4$He($\gamma$,$n$)$^3$He. The $^6$Li abundance, however, could show a sizable change and therefore the future precise measurement of the cross sections at high energy $E_\gamma \gtrsim$ 50 MeV is highly required.Comment: 10 pages, 7 figures, conclusion not changed, to be published in PR

Big Bang Nucleosynthesis with long-lived strongly interacting relic particles

We study effects of relic long-lived strongly interacting massive particles (X particles) on big bang nucleosynthesis (BBN). The X particle is assumed to have existed during the BBN epoch, but decayed long before detected. The interaction strength between an X and a nucleon is assumed to be similar to that between nucleons. Rates of nuclear reactions and beta decay of X-nuclei are calculated, and the BBN in the presence of neutral charged X^0 particles is calculated taking account of captures of X^0 by nuclei. As a result, the X^0 particles form bound states with normal nuclei during a relatively early epoch of BBN leading to the production of heavy elements. Constraints on the abundance of X^0 are derived from observations of primordial light element abundances. Particle models which predict long-lived colored particles with lifetimes longer than about 200 s are rejected. This scenario prefers the production of 9Be and 10B. There might, therefore, remain a signature of the X particle on primordial abundances of those elements. Possible signatures left on light element abundances expected in four different models are summarized.Comment: 6 pages, 2 figures, to appear in the Proceedings of IAU Symposium 268: Light elements in the Universe (C. Charbonnel, M. Tosi, F. Primas, C. Chiappini, eds.; Cambridge Univ. Press

Differential scanning fluorimetric analysis of the amino-acid binding to taste receptor using a model receptor protein, the ligand-binding domain of fish T1r2a/T1r3

Taste receptor type 1 (T1r) is responsible for the perception of essential nutrients, such as sugars and amino acids, and evoking sweet and umami (savory) taste sensations. T1r receptors recognize many of the taste substances at their extracellular ligand-binding domains (LBDs). In order to detect a wide array of taste substances in the environment, T1r receptors often possess broad ligand specificities. However, the entire ranges of chemical spaces and their binding characteristics to any T1rLBDs have not been extensively analyzed. In this study, we exploited the differential scanning fluorimetry (DSF) to medaka T1r2a/T1r3LBD, a current sole T1rLBD heterodimer amenable for recombinant preparation, and analyzed their thermal stabilization by adding various amino acids. The assay showed that the agonist amino acids induced thermal stabilization and shifted the melting temperatures (T-m) of the protein. An agreement between the DSF results and the previous biophysical assay was observed, suggesting that DSF can detect ligand binding at the orthostericbinding site in T1r2a/T1r3LBD. The assay further demonstrated that most of the tested Lamino acids, but no D-amino acid, induced T-m shifts of T1r2a/T1r3LBD, indicating the broad L-amino acid specificities of the proteins probably with several different manners of recognition. The T-m shifts by each amino acid also showed a fair correlation with the responses exhibited by the full-length receptor, verifying the broad amino-acid binding profiles at the orthosteric site in LBD observed by DSF

瀬戸内海中央部におけるトラフグの産卵に関する研究

　トラフクの産卵については従来まったく知られていなかった.われわれは， 1960年および1961年の4-5月，瀬戸内海中央部において，本種の産卵に関する研究を行ない，次の結果をえた. 1) 備讃瀬戸におけるトラフグ漁場は，水深20m以上の比較的潮流の早い場所IL 局在している.漁期は4月中旬-5月中旬であり，産卵群を漁獲の対象としている.従って，これら漁場は同時にトラフグの産卵場である. 2) 産卵群の形態的特徴を明らかにした.タイ縛網に混獲される産卵群の性比は，雄3:雌1の割合であった.全長平均値閣の雌雄差は認められなかったが，体重平均値聞にみられる両者の差は極めて有意であり，雌が大きい. 3) 卵巣内における卵の発達は，一様に進行する.とのζ とから，放卵は一回あるいはきわめて短期間に完了するものと推定される. 4) 字卵数(N) と全長(L，mm) および体重(W， g) との関係は，それぞれ次の指数式で表わすことができる。 N=0.0000312・L3.862; N =0.0120W1.161. 5) トラフグ漁場の底質中より，天然に産着された多量のトラフグ卵の採集に成功し，産卵場を確認することができた. 6) 産着卵数と底質の粒子組成との聞にみられる関係から，産卵床の特徴を明らかにすることができた.卵の最も多く見出された場所は，径2-4mmの粒子の卓越する(重量組成)場所であった.底質が細砂，粗様よりなる場所からは，殆んどあるいは全く産着卵は採集できなかった.1) In order to make clear the fecundity and spawning of a puffer, Fugu rubripes T. et S., investigations were carried out in the central waters of the Inland Sea of Japan in April-May, I960-I961. 2) Distribution of the fishing grounds of Fugu rubripes in Bisan Strait was shown. 3) Morphological characteristics of the spawners of Fugu rubripes were clarified. Sex-ratio (female: male) of the spawners caught by seine-nets was approximately 1: 3. Females were significantly greater in weight than in males, while the difference in total length between both sexes was not significant. 4) Development of ovarian eggs seems to be advanced uniformly within an ovary, which makes reasonable to consider that the spawning may occur at a time or at least in a very short period. 5) Relationships of fecundity with total length and weight of body were clarified. 6) Successful collection of the eggs deposited on natural spawning beds was made. The data obtained in the present investigation show that the spawning beds of Fugu rubripes lie in the bottoms having particle-size of sand 2-4 mm. in diameter

New results on catalyzed BBN with a long-lived negatively-charged massive particle

It has been proposed that the apparent discrepancies between the inferred primordial abundances of 6Li and 7Li and the predictions of big bang nucleosynthesis (BBN) can be resolved by the existence of a negatively-charged massive unstable supersymmetric particle (X-) during the BBN epoch. Here, we present new BBN calculations with an X- particle utilizing an improved nuclear reaction network including captures of nuclei by the particle, nuclear reactions and beta-decays of normal nuclei and nuclei bound to the X- particles (X-nuclei), and new reaction rates derived from recent rigorous quantum many-body dynamical calculations. We find that this is still a viable model to explain the observed 6Li and 7Li abundances. However, contrary to previous results, neutral X-nuclei cannot significantly affect the BBN light-element abundances. We also show that with the new rates the production of heavier nuclei is suppressed and there is no signature on abundances of nuclei heavier than Be in the X--particle catalyzed BBN model as has been previously proposed. We also consider the version of this model whereby the X- particle decays into the present cold dark matter. We analyze the this paradigm in light of the recent constraints on the dark-matter mass deduced from the possible detected events in the CDMS-II experiment. We conclude that based upon the inferred range for the dark-matter mass, only X- decay via the weak interaction can achieve the desired 7Li destruction while also reproducing the observed 6Li abundance.Comment: 6 pages, 2 figure

Large-cell neuroendocrine carcinoma of lung with epidermal growth factor receptor (EGFR) gene mutation and co-expression of adenocarcinoma markers: a case report and review of the literature

PURPOSE: A high rate of response to treatment with epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) has been observed in certain patients (women, of East Asian ethnicity, with non-smoking history and adenocarcinoma histology) with mutations in exons 18 to 21 of the tyrosine kinase domain of EGFR. Some cases of high-grade neuroendocrine carcinoma of the lung harboring mutations have been sporadically reported. METHODS: We describe the case of a 78-year-old woman with large-cell neuroendocrine carcinoma of the lung, with mutation in exon 21 L858R and co-expression of adenocarcinoma markers. RESULTS: A mass (3.0 cm in diameter) was identified in the inferior lobe of the left lung, accompanied by metastases into ipsilateral mediastinal lymph nodes and elevations of serum pro-gastrin-releasing peptide and carcinoembryonic antigen. Initial transbronchial brushing cytology suggested high-grade neuroendocrine carcinoma favoring small-cell carcinoma in poorly smeared and degenerated preparations, and revealed exon 21 L858R mutation. Re-enlargement of the cancer and bone metastases was observed after chemotherapy, and further testing suggested large-cell neuroendocrine carcinoma with immunoreactivity to markers of primary lung adenocarcinoma and L858R mutation. High-grade neuroendocrine carcinoma with mutations in the tyrosine kinase domain of EGFR may be associated with adenocarcinoma, as reviewed from the literature and may also apply to our case. CONCLUSIONS: EGFR-TKI could provide better quality of life and survival in patients with advanced or relapsed high-grade neuroendocrine carcinoma with EGFR gene mutations. Further studies in this respect are warranted

Breakdown of a Mott insulator -- non-adiabatic tunneling mechanism

Time-dependent nonequilibrium properties of a strongly correlated electron system driven by large electric fields is obtained by means of solving the time-dependent Schr\"odinger equation for the many-body wave function numerically in one dimension. While the insulator-to-metal transition depends on the electric field and the interaction, the metallization is found to be described in terms of a universal Landau-Zener quantum tunneling among the many-body levels. These processes induces current oscillation for small systems, while give rise to finite resistivity through dissipation for larger systems/on longer time scales.Comment: 5 pages, 5 figures, version to appear in Phys.Rev.Let

Structural basis of enzyme activity regulation by the propeptide of l-lysine α-oxidase precursor from Trichoderma viride

Harmuful proteins are usually synthesized as inactive precursors and are activated by proteolytic processing. l-Amino acid oxidase (LAAO) is a flavoenzyme that catalyzes the oxidative deamination of l-amino acid to produce a 2-oxo acid with ammonia and highly toxic hydrogen peroxide and, therefore, is expressed as a precursor. The LAAO precursor shows significant variation in size and the cleavage pattern for activation. However, the molecular mechanism of how the propeptide suppresses the enzyme activity remains unclear except for deaminating/decarboxylating Pseudomonasl-phenylalanine oxidase (PAO), which has a short N-terminal propeptide composed of 14 residues. Here we show the inactivation mechanism of the l-lysine oxidase (LysOX) precursor (prLysOX), which has a long N-terminal propeptide composed of 77 residues, based on the crystal structure at 1.97 Å resolution. The propeptide of prLysOX indirectly changes the active site structure to inhibit the enzyme activity. prLysOX retains weak enzymatic activity with strict specificity for l-lysine and shows raised activity in acidic conditions. The structures of prLysOX crystals that soaked in a solution with various concentrations of l-lysine have revealed that prLysOX can adopt two conformations; one is the inhibitory form, and the other is very similar to mature LysOX. The propeptide region of the latter form is disordered, and l-lysine is bound to the latter form. These results indicate that prLysOX uses a different strategy from PAO to suppress the enzyme activity and suggest that prLysOX can be activated quickly in response to the environmental change without proteolytic processing