Infrared and hard X-ray diagnostics of AGN identification from the Swift/BAT and AKARI all-sky surveys

We combine data from two all-sky surveys in order to study the connection between the infrared and hard X-ray (>10keV) properties for local active galactic nuclei (AGN). The Swift/Burst Alert Telescope all-sky survey provides an unbiased, flux-limited selection of hard X-ray detected AGN. Cross-correlating the 22-month hard X-ray survey with the AKARI all-sky survey, we studied 158 AGN detected by the AKARI instruments. We find a strong correlation for most AGN between the infrared (9, 18, and 90 micron) and hard X-ray (14-195 keV) luminosities, and quantify the correlation for various subsamples of AGN. Partial correlation analysis confirms the intrinsic correlation after removing the redshift contribution. The correlation for radio galaxies has a slope and normalization identical to that for Seyfert 1s, implying similar hard X-ray/infrared emission processes in both. In contrast, Compton-thick sources show a large deficit in the hard X-ray band, because high gas column densities diminish even their hard X-ray luminosities. We propose two photometric diagnostics for source classification: one is an X-ray luminosity vs. infrared color diagram, in which type 1 radio-loud AGN are well isolated from the others in the sample. The other uses the X-ray vs. infrared color as a useful redshift-independent indicator for identifying Compton-thick AGN. Importantly, Compton-thick AGN and starburst galaxies in composite systems can also be differentiated in this plane based upon their hard X-ray fluxes and dust temperatures. This diagram may be useful as a new indicator to classify objects in new and upcoming surveys such as WISE and NuSTAR.Comment: 17 pages, 5 figures, 5 tables. Accepted for publication in the Astrophysical Journa

Proposal of a addressing mechanism for ad-hoc network

アドホックネットワークは1990年代末以降活発に研究がなされてきた。現在、アドホックネットワークの課題として経路探索に伴うノード検索パケットによるネットワーク帯域の消費がある。この間題に対する一つの解決手法としてノードに位置情報としての意味を持たせ、それを基にルーティングを行うGreedyルーティングプロトコルと呼ばれるプロトコル群がある　Greedyルーティングプロトコルでは位置情報を基にルーティングを行うためルーティングアルゴリズムとは別にネットワーク内の端末にアドレスを割り当てる機構が組み込まれている場合があるが、既存手法では位置情報として地理的な情報を元にしているためノード間の接続状況を反映したものとはならない。そこで本報告ではノードの位置情報と接続情報を考慮ことで既存の割当手法に比べ破棄パケットの発生を低減する手法 を提案する。 Prom the end of 1990's, lots of researchers have discussed the ad-hoc networks. We consider that searching node packets to establish a path to a destination node in ad-hoc networks consume network bandwidth. Several Greedy forwarding protocols, which axe based on information of node location, have been proposed to solve this problem. Greedy forwarding protocol usually has addressing mechanism that assigns IP address according to location information of nodes. However, the information of existing techniques does not reflect link state. In this report, we propose a mechanism for addressing, which lowers rate of loss packets than existing mechanism with the position information reflection of link state

Disturbed hippocampal intra-network in first-episode of drug-naïve major depressive disorder

Complex networks inside the hippocampus could provide new insights into hippocampal abnormalities in various psychiatric disorders and dementia. However, evaluating intra-networks in the hippocampus using MRI is challenging. Here, we employed a high spatial resolution of conventional structural imaging and independent component analysis to investigate intra-networks structural covariance in the hippocampus. We extracted the intra-networks based on the intrinsic connectivity of each 0.9 mm isotropic voxel to every other voxel using a data-driven approach. With a total volume of 3 cc, the hippocampus contains 4115 voxels for a 0.9 mm isotropic voxel size or 375 voxels for a 2 mm isotropic voxel of high-resolution functional or diffusion tensor imaging. Therefore, the novel method presented in the current study could evaluate the hippocampal intra-networks in detail. Furthermore, we investigated the abnormality of the intra-networks in major depressive disorders. A total of 77 patients with first-episode drug-naïve major depressive disorder and 79 healthy subjects were recruited. The independent component analysis extracted seven intra-networks from hippocampal structural images, which were divided into four bilateral networks and three networks along the longitudinal axis. A significant difference was observed in the bilateral hippocampal tail network between patients with major depressive disorder and healthy subjects. In the logistic regression analysis, two bilateral networks were significant predictors of major depressive disorder, with an accuracy of 78.1%. In conclusion, we present a novel method for evaluating intra-networks in the hippocampus. One advantage of this method is that a detailed network can be estimated using conventional structural imaging. In addition, we found novel bilateral networks in the hippocampus that were disturbed in patients with major depressive disorders, and these bilateral networks could predict major depressive disorders

Contribution of sellar dura integrity to symptom manifestation in pituitary adenomas with intratumoral hemorrhage

Purpose: Although hemorrhage within pituitary adenomas frequently exacerbates the symptoms, there are many grades of severity. Moreover, the contributing factors for symptom severity are still controversial. Methods: This retrospective study included 82 patients who underwent transsphenoidal surgery for pituitary adenomas with intratumoral hemorrhage. The grades of preoperative symptoms were classified into group A, asymptomatic or minor symptoms; group B, moderate symptoms sufficient for complain; and group C, severe symptoms disturbing daily life. Results: The hemorrhage volume within an adenoma was significantly higher in group C (92.6%) than in groups A (48.6%) and B (58.7%). Both headache and diplopia were dominant in group C, occurring in 72.2% and 27.8% of the patients, respectively. In group C, there was no significant difference in frequency between adenoma extensions into the sphenoid sinus (0%) and involvement of the cavernous sinus of Knosp grade 4 (0%), and extensions into the suprasellar region were not common (38.9%). The most distinctive feature was that “no extrasellar extension” was found only in group C (41.2%), and “multidirectional extension” was not detected in this group (0%). Multiple regression analysis revealed that the most powerful determining factors were the high frequencies of intratumoral hemorrhage and lack of extrasellar and multidirectional extensions. Conclusion: Rapid volume expansion of a hematoma and lack of extension or unidirectional extension might lead to significant compression of the sellar and surrounding structures. Of note, the integrity of the sellar dura might contribute to the acute onset of symptom manifestations caused by hemorrhage in pituitary adenomas. © 2017 Springer Science+Business Media, LLCEmbargo Period 12 month

Clinical impact of acute hyperglycemia on development of diabetes mellitus in non-diabetic patients with acute myocardial infarction

AbstractBackgroundAcute hyperglycemia (AH) after the onset of acute myocardial infarction (AMI) is a manifestation of transient abnormal glucose metabolism that may reflect AMI severity, and thus be a predictor of poor prognosis. However, it remains unknown whether AH may predict development of de novo diabetes mellitus (dn-DM) in non-diabetic AMI patients.Methods and resultsAmong AMI patients registered in the Osaka Acute Coronary Insufficiency Study between 1998 and 2007, we investigated hospital records of 1493 patients who had an admission glycated hemoglobin A1c (HbA1c) level of ≤6.0% and were subjected to glycometabolic profiling after survival discharge. dn-DM was defined as initiation of diabetic medication or documentation of an HbA1c level of ≥6.5% during the 5-year follow-up period. AH, defined as an admission serum glucose level of ≥200mg/dl, was observed in 133 (8.9%) patients. dn-DM development was more frequent in post-AMI patients with AH than those without [24.8% vs 12.0%, adjusted hazard ratio (HR) 1.776, p=0.021], particularly among patients with an HbA1c of <5.6% on admission. Treatment with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers was associated with a reduced incidence of dn-DM in patients with AH (adjusted HR 0.397, p=0.031).ConclusionAdmission AH was a predictor of dn-DM in non-diabetic post-AMI patients. Renin–angiotensin system inhibitors were associated with reduced incidence of dn-DM in post-AMI patients with AH

Preoperative Evaluation of the Interface Between Tuberculum Sellae Meningioma and the Optic Nerves on Fast Imaging with Steady-State Acquisition for Extended Endoscopic Endonasal Transsphenoidal Surgery

Introduction Endoscopic endonasal transsphenoidal surgery (EETS) is increasingly applied to treat tuberculum sellae meningiomas. However, if the tumor adheres firmly to the optic nerve, dissection of the interface between both structures should be prudent to preserve visual function. The purpose of this study was to investigate whether tumor adhesion to the optic nerve can be predicted preoperatively by fast imaging with steady-state acquisition (FIESTA). Methods Twenty-two patients with tuberculum sellae meningioma treated with EETS were retrospectively identified. Clinical characteristics, radiologic studies, intraoperative findings, and outcomes were reviewed from their clinical charts. Results Patients\u27 symptoms included visual function impairment in 18 patients and headaches in 4 patients. Symptoms were resolved in 19 patients after operation. Preoperative radiologic evaluation was performed in 44 sides (22 patients) of the interface between tumors and the optic nerves and showed absence of peritumoral hyperintensity on FIESTA in 7 sides in 7 patients. In 5 of the 7 sides, tumor dissection was complicated by firm adhesion to the optic nerves. Among these cases, visual functions were unchanged in 1 patient after complete removal of the adhesion but substantially improved in 3 patients after partial resection. In the remaining 37 sides with preoperative peritumoral hyperintensity, no adhesion was found between both structures intraoperatively. Conclusions Absence of peritumoral hyperintensity between tuberculum sellae meningioma and the optic nerve on FIESTA may indicate firm adhesion at the interface, severely complicating complete removal. Preoperative recognition of this adhesion is important for safe tumor removal and preservation of visual functions. © 2017 Elsevier Inc.Embargo Period 12 month

The brain-derived neurotrophic factor Val66Met polymorphism increases segregation of structural correlation networks in healthy adult brains

Background Although structural correlation network (SCN) analysis is an approach to evaluate brain networks, the neurobiological interpretation of SCNs is still problematic. Brain-derived neurotrophic factor (BDNF) is well-established as a representative protein related to neuronal differentiation, maturation, and survival. Since a valine-to-methionine substitution at codon 66 of the BDNF gene (BDNF Val66Met single nucleotide polymorphism (SNP)) is well-known to have effects on brain structure and function, we hypothesized that SCNs are affected by the BDNF Val66Met SNP. To gain insight into SCN analysis, we investigated potential differences between BDNF valine (Val) homozygotes and methionine (Met) carriers in the organization of their SCNs derived from inter-regional cortical thickness correlations. / Methods Forty-nine healthy adult subjects (mean age = 41.1 years old) were divided into two groups according to their genotype (n: Val homozygotes = 16, Met carriers = 33). We obtained regional cortical thickness from their brain T1 weighted images. Based on the inter-regional cortical thickness correlations, we generated SCNs and used graph theoretical measures to assess differences between the two groups in terms of network integration, segregation, and modularity. / Results The average local efficiency, a measure of network segregation, of BDNF Met carriers’ network was significantly higher than that of the Val homozygotes’ (permutation p-value = 0.002). Average shortest path lengths (a measure of integration), average local clustering coefficient (another measure of network segregation), small-worldness (a balance between integration and segregation), and modularity (a representative measure for modular architecture) were not significantly different between group (permutation p-values ≧ 0.01). / Discussion and Conclusion Our results suggest that the BDNF Val66Met polymorphism may potentially influence the pattern of brain regional morphometric (cortical thickness) correlations. Comparing networks derived from inter-regional cortical thickness correlations, Met carrier SCNs have denser connections with neighbors and are more distant from random networks than Val homozygote networks. Thus, it may be necessary to consider potential effects of BDNF gene mutations in SCN analyses. This is the first study to demonstrate a difference between Val homozygotes and Met carriers in brain SCNs

COMT Val158Met, but not BDNF Val66Met, is associated with white matter abnormalities of the temporal lobe in patients with first-episode, treatment-naïve major depressive disorder: a diffusion tensor imaging study

We investigated the association between the Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene, the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene, and white matter changes in patients with major depressive disorder (MDD) and healthy subjects using diffusion tensor imaging (DTI). We studied 30 patients with MDD (17 males and 13 females, with mean age ± standard deviation [SD] =44±12 years) and 30 sex- and age-matched healthy controls (17 males and 13 females, aged 44±13 years). Using DTI analysis with a tract-based spatial statistics (TBSS) approach, we investigated the differences in fractional anisotropy, radial diffusivity, and axial diffusivity distribution among the three groups (patients with the COMT gene Val158Met, those with the BDNF gene Val66Met, and the healthy subjects). In a voxel-wise-based group comparison, we found significant decreases in fractional anisotropy and axial diffusivity within the temporal lobe white matter in the Met-carriers with MDD compared with the controls (P<0.05). No correlations in fractional anisotropy, axial diffusivity, or radial diffusivity were observed between the MDD patients and the controls, either among those with the BDNF Val/Val genotype or among the BDNF Met-carriers. These results suggest an association between the COMT gene Val158Met and the white matter abnormalities found in the temporal lobe of patients with MDD

Proposal of clustering technique in P2P network

近年、ファイル共有やコミュニケーションツールなどにおいて、 P2Pネットワークアプリケーションが注目を集めている　P2Pネットワークでは効率的な検索や負荷分散などのため、クラスタリングと呼ばれるピアをグループ化する手法が使用されている。しかし、既存のクラスタリングは各ピアのクラスタ用パラメータが頻繁に変化した場合を想定しておらず、ユーザ同士の会話の内容によってグループ化を行うサービスなどには適さない。そこで本報告では、あえて明確なグループ化を行わないことによって柔軟なクラスタリングを行う手法を提案する.また、本手法の適応例としてオンラインゲームの多人数参加型テトリスを実装した。 In recent years, lots of file sharing applications and communication tools based on the P2P network system have been used. On the P2P network, grouping mechanism called clustering is used to increase efficiency of information search or load balancing. However, existing clustering mechanisms does not react to frequent move of peer. Therefore, these axe not suitable for network applications such as communication tools based on groups of peer which are organized according to content of communication. In this report, we proposed clustering mechanism which does not provide strict grouping but flexible grouping, by which a peer is allowed to belong to several groups. Furthermore, we implemented trial application, massively multiplayer online Tetris, as example of network application with proposal clustering mechanism