Mott insulating state in a quarter-filled two-orbital Hubbard chain with different bandwidths

We investigate the ground-state properties of the one-dimensional two-band Hubbard model with different bandwidths. The density-matrix renormalization group method is applied to calculate the averaged electron occupancies $n$ as a function of the chemical potential $\mu$. Both at quarter and half fillings, "charge plateaux" appear in the $n$-$\mu$ plot, where $d\mu/dn$ diverges and the Mott insulating states are realized. To see how the orbital polarization in the one-quarter charge plateau develops, we apply the second-order perturbation theory from the strong-coupling limit at quarter filling. The resultant Kugel-Khomskii spin-orbital model includes a $magnetic$ field coupled to orbital pseudo-spins. This field originates from the discrepancy between the two bandwidths and leads to a finite orbital pseudo-spin magnetization.Comment: 4 pages, 2 figures, Proceedings of LT2

The internet as an occupation : The relation between the disabled person and the internet according to data in newspapers

「新聞の記事の中で出現する障害者とインターネットのかかわりは,作業療法における作業の概念でとらえるとどのような特性があるのか」という研究疑問を設定し,障害者のインターネット利用状況に関する枠組み作りを試みた.今回の研究では,全国紙の新聞1紙を対象とし,データとして検出した記事の類似した内容をまとめ,KJ法の考え方を用いて,共通した概念を抽出する方法で行った.この手順は,KJ法を基に開発されたコンピュータープログラムであるISOP-KJ法を補助的に使用した.その分析の結果,6つの大きなカテゴリーを抽出した.インターネットの活用は,作業療法でいう,作業療法として追及していく「作業」を強力に実現していく手段であり,目的にもなり得るという仮説を形成できた.インターネットを利用しての「自己維持活動」,「仕事」,「遊び」,「社会参加」は,「コンピュータによって形成される身体的な接触のない状態で情報伝達が生じる環境」の結果生じる作業といえるので,「バーチャル作業(virtual occupation)」と定義できると考えた. ““The internet can be very helpful if it is fully made use of by the disabled person."This statementmay be true, but the questions arise in what ways, in what fields and to what extent it can be useful.Inorder to obtain answers to those questions, we undertook research through a technique similar to the KJ-method, by collecting related articles from a certain nationally-circulated newspaper as data. Finally, thisdata verified that the internet makes it possible for the disabled to take part in social activities more easilyand willingly and to improve their activities in daily life, both their productive activities and their leisureactivities. We believe that we can define the activities produced by utilizing the internet as a virtualoccupation

Survival outcomes of hepatectomy for stage B Hepatocellular carcinoma in the BCLC classification

Background: Because hepatectomy is not recommended in patients with stage B hepatocellular carcinoma (HCC) of the Barcelona Clinic Liver Cancer (BCLC) staging, we evaluated the survival outcomes of hepatectomy for stage B in the BCLC system. Methods: Data were collected from 297 consecutive adult stage B patients who underwent curative hepatectomy for HCC between 1996 and 2014 in Hokkaido University Hospital. Overall survival (OS), disease-free survival (DFS), and risk factors were analyzed using the Kaplan-Meier method. Independent prognostic factors were evaluated using a Cox proportional hazards regression model. AP-factor (alpha-fetoprotein [AFP] × protein induced by vitamin K absence or antagonism factor II [PIVKA-II]) was categorized according to the serum concentrations of AFP and PIVKA-II: AP1 (AFP < 200 ng/ml and PIVKA-II < 100 mAU/ml), AP2 (AFP × PIVKA-II < 10^5), and AP3 (AFP × PIVKA-II ≥ 10^5). Results: There were 130 deaths among our 297 stage B patients (43.8%). The causes of death in these cases were HCC recurrence (n = 106; 81.5%), liver failure (n = 7; 5.4%), and other causes (n = 17; 16.1%). The operative mortality rate was 0.34% (1/297). The 5-year OS and DFS rates for the stage B cases were 54.3 and 21.9%, respectively. By multivariate analysis, tumor number and AP-factor were risk factors for both survival and recurrence that were tumor related and could be evaluated preoperatively. The study patients with stage B HCC were classified into three groups by tumor number (B1, 1; B23, 2 or 3; B4over: ≥4) and into three groups stratified by AP-factor (AP1, AP2, and AP3). The 5-year OS rates of B1, B23, and B4over were 63.6, 52.3, and 29.0%. The 5-year OS rates of AP1, AP2, and AP3 were 67.6, 65.2, and 39.1%. Stratified by the 5-year OS rate, stage B HCC patients were classified into three subgroups (A-C).The 5-year OS rates of groups A (B1 or B23 and AP-1 or AP-2), B (B1 or B23 and AP-3, or B4over and AP-1 or AP-2), and C (B4over and AP-3) were 69.5, 43.7, and 21.3%. Conclusion: Stage B HCC patients with a tumor number ≤ 3 and/or AP-factor < 1 × 10^5 show acceptable 5-year OS rates and could be treated by hepatectomy

Expression of UV-Sensitive Parapinopsin in the Iguana Parietal Eyes and Its Implication in UV-Sensitivity in Vertebrate Pineal-Related Organs

The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles

Beta-Arrestin Functionally Regulates the Non-Bleaching Pigment Parapinopsin in Lamprey Pineal

The light response of vertebrate visual cells is achieved by light-sensing proteins such as opsin-based pigments as well as signal transduction proteins, including visual arrestin. Previous studies have indicated that the pineal pigment parapinopsin has evolutionally and physiologically important characteristics. Parapinopsin is phylogenetically related to vertebrate visual pigments. However, unlike the photoproduct of the visual pigment rhodopsin, which is unstable, dissociating from its chromophore and bleaching, the parapinopsin photoproduct is stable and does not release its chromophore. Here, we investigated arrestin, which regulates parapinopsin signaling, in the lamprey pineal organ, where parapinopsin and rhodopsin are localized to distinct photoreceptor cells. We found that beta-arrestin, which binds to stimulated G protein-coupled receptors (GPCRs) other than opsin-based pigments, was localized to parapinopsin-containing cells. This result stands in contrast to the localization of visual arrestin in rhodopsin-containing cells. Beta-arrestin bound to cultured cell membranes containing parapinopsin light-dependently and translocated to the outer segments of pineal parapinopsin-containing cells, suggesting that beta-arrestin binds to parapinopsin to arrest parapinopsin signaling. Interestingly, beta-arrestin colocalized with parapinopsin in the granules of the parapinopsin-expressing cell bodies under light illumination. Because beta-arrestin, which is a mediator of clathrin-mediated GPCR internalization, also served as a mediator of parapinopsin internalization in cultured cells, these results suggest that the granules were generated light-dependently by beta-arrestin-mediated internalization of parapinopsins from the outer segments. Therefore, our findings imply that beta-arrestin-mediated internalization is responsible for eliminating the stable photoproduct and restoring cell conditions to the original dark state. Taken together with a previous finding that the bleaching pigment evolved from a non-bleaching pigment, vertebrate visual arrestin may have evolved from a “beta-like” arrestin by losing its clathrin-binding domain and its function as an internalization mediator. Such changes would have followed the evolution of vertebrate visual pigments, which generate unstable photoproducts that independently decay by chromophore dissociation