The eigenvalue problem for infinite compact complex symmetric matrices with application to the numerical computation of complex zeros of J0(z) − iJ1(z) and of Bessel functions Jm(z) of any real order m

AbstractConsider computing simple eigenvalues of a given compact infinite matrix re- garded as operating in the complex Hilbert space l2 by computing the eigenvalues of the truncated finite matrices and taking an obvious limit. In this paper we deal with a special case where the given matrix is compact, complex, and symmetric (but not necessarily Hermitian). Two examples of application are studied. The first is con- cerned with the equation J0(z) − iJ1(z)=0 appearing in the analysis of the solitary-wave runup on a sloping beach, and the second with the zeros of the Bessel function Jm(z) of any real order m. In each case, the problem is reformulated as an eigenvalue problem for a compact complex symmetric tridiagonal matrix operator in l2 whose eigenvalues are all simple. A complete error analysis for the numerical solution by truncation is given, based on the general theorems proved in this paper, where the usefulness of the seldom used generalized Rayleigh quotient is demonstrated

コウコウセイ ノ ガッコウ テキオウ ニカンスル ジュウダンテキ ケンキュウ ジュウヨウ ナ タシャ トノ カンケイ ト ガッコウ フンイキ ノ エイキョウ

本研究の目的は、高校生にとって重要な他者である親、友人および教師との関係、入学した学校満足度と学級凝集性が、その後の中途退学や学校適応にどのように影響するのかを明らかにすることである。高校1 年生202 名に対し、1 年生時1 学期、1 年生時3 学期および2 年生時3 学期に3 回、これらの変数を繰り返し測定した。データに不備のなかった198 名を中退と学校適応の違いに応じて5 群に分割し、それぞれの変数を従属変数として分散分析を行った。その結果、2 年生で中退する生徒が親との関係が低いという特徴が見られた。また、学校適応に関しては、学校満足度が影響することが明らかになった。中退する生徒や学校適応に問題が生じる生徒を早期に発見する手がかりを得ることができた。一方、今回の研究協力者独自の結果と考えられる面もあり、今後、多様な高校での調査が必要であると言える。The purpose of this study was to confirm some factors that predicted dropouts and students having poor adjustment to schools. We selected one senior high school having many dropouts every year, and conducted a longitudinal research study for three years. The data of 198 students on interpersonal relations and attitudes toward school and classes were collected three times, during the first, and third terms in the first year, and during the third term in the second year. The students were divided into five groups: dropouts in the first year, dropouts in the second year, low adjustment students, medium adjustment students and high adjustment students. ANOVA showed that a deficit in relation to parent in the dropout groups was salient, and that satisfaction at school among high adjustment students was higher than in other groups.研究論文(Article

コウコウ チュウタイ ヨソク ヨウイン ノ ケイジテキ ケンキュウ

本研究の目的は、高校中退を予測すると考えられる認知的要因と動機づけ要因を継時的に測定することによって、高校中退の原因を検討することである。高校1年生194名を対象に、卒業までの3年間、追跡調査を行った。1年生時4月に質問紙を課し、入学動機や動機づけ特性など比較的変容しにくい認知的・動機づけ的要因を測定した。学校への満足度や対人関係といった比較的変容しやすい認知的・動機づけ的要因については、1年生時6月と翌年2月に同じ質問紙をくりかえし課すことによって測定した。3年間の間に高校を中退した中退群（40名）と卒業した卒業群（154名）を各変数について比較したところ、中退群は卒業群よりも（1）親の学校への関心が低く、（2）学校への満足感が低く、（3）学級の凝集性認知が低いことがわかった。また、中退群は、6月から2月にかけて、学校への満足感と学級の凝集性認知がさらに低下していることが明らかになった。This　article　describes　the　cognitive　and　motivational　variables／that　would　have　predictive value　for　school　dropouts．　The　subjects　were　194　students　in　a　commercial　high　schooL　Two questionnaires　measuring　the　cognitive　and　motivational　variables　were．administered　at　the beginning　of　the　first　academic　year．　And　again，　one　of　two　questionnaires　was　assigned　to students　around　the　end　of　the　first　academic　year．　In　the　following　three　years，　forty　students left　school　without　completing　their　studies．　We　tested　the　differences　in　cognitive　and motivational　variables　between　the　dropout　group　and　the　completion　group．　Results　showed　that students　in　the　dropout　group　were　lower　than　those　of　the　completion　group　on　parent’s　concern with　schoo1，　satisfaction　with　school，　and　group　cohesion　in　class．　Students　of　the　dropout　group went　from　low　to　lower　in　a　year　on　satisfaction　with　school　and　group　cohesion　in　class

Gender and coronary artery bypass graft surgery

Background Traditional and non-traditional risk factors for atherosclerotic cardiovascular disease (ASCVD) are different between men and women. Gender-linked impact of epicardial adipose tissue volume (EATV) in patients undergoing coronary artery bypass grafting (CABG) remains unknown. Methods Gender-linked impact of EATV, abdominal fat distribution and other traditional ASCVD risk factors were compared in 172 patients (men: 115; women: 57) who underwent CABG or non-coronary valvular surgery (non-CABG). Results In men, EATV, EATV index (EATV/body surface area) and the markers of adiposity such as body mass index, waist circumference and visceral fat area were higher in the CABG group than in the non-CABG group. Traditional ASCVD risk factors were also prevalent in the CABG group. In women, EATV and EATV index were higher in the CABG group, but other adiposity markers were comparable between CABG and non-CABG groups. Multivariate logistic regression analysis showed that in men, CABG was determined by EATV Index and other ASCVD risk factors including hypertension, dyslipidemia, adiponectin, high sensitive C-reactive protein (hsCRP) and type 2 diabetes mellitus (Corrected R2 = 0.262, p < 0.0001), while in women, type 2 diabetes mellitus is a single strong predictor for CABG, excluding EATV Index (Corrected R2 = 0.266, p = 0.005). Conclusions Our study found that multiple risk factors, including epicardial adipose tissue volume and traditional ASCVD factors are determinants for CABG in men, but type 2 diabetes mellitus was the sole determinant in women. Gender-specific disparities in risk factors of CABG prompt us to evaluate new diagnostic and treatment strategies and to seek underlying mechanisms

Sequential free right internal thoracic artery grafting for multivessel coronary artery bypass grafting

ObjectivesThis study compared early and follow-up angiographic results of individual and sequential grafting with the free right internal thoracic artery (RITA).MethodsWe reviewed 334 patients who underwent multivessel coronary artery bypass grafting with the free RITA between September 2004 and December 2010. The free RITA was used for individual grafting in 179 patients and for sequential grafting in 155 patients. We compared operative and postoperative variables and early and follow-up angiographic patency rates of distal anastomoses of the free RITA between the groups.ResultsThe mean number of distal anastomoses in sequential grafting was 2.2 ± 0.4. The inflow of the free RITA included the aorta (27.4%) and other grafts (72.6%) in the individual group. The inflow of free RITA was exclusively other grafts in the sequential group. Operative mortality and incidence of postoperative complications were not significantly different between groups. Overall patency rate of distal anastomosis of the free RITA was 99.1% at early angiography and 91.8% at follow-up angiography, and the rate did not differ significantly between individual and sequential grafting (early, 98.6% vs 99.3%; follow-up, 93.0% vs 91.2%).ConclusionsMultivessel coronary artery bypass grafting with the free RITA is safe and useful. Patency rates of distal anastomoses are similar between individual and sequential grafting with the free RITA at early and follow-up angiography. When the RITA cannot be used as an in situ graft for multiple anastomoses, sequential grafting with the free RITA should be considered

Long-term outcomes of artificial chordal replacement with tourniquet technique in mitral valve repair: A single-center experience of 700 cases

ObjectiveArtificial chordal replacement has been shown to be effective and durable, with numerous techniques reported. However, the outcomes of each technique have remained poorly defined. We report the long-term outcomes of the tourniquet technique.MethodsWe reviewed the data from 700 patients who had undergone mitral valve repair with the tourniquet technique from 1992 to 2010. We analyzed the operative outcomes, long-term survival rate, freedom from reoperation, and freedom from recurrent moderate or severe mitral regurgitation (MR). We also performed Cox regression analysis to explore the predictors of recurrent MR after mitral valve repair using the tourniquet technique.ResultsThe mean age was 54.7 ± 14.9 years; 212 patients (30.3%) had anterior leaflet prolapse, 142 (20.3%) had posterior leaflet prolapse, and 346 (49.4%) had bileaflet prolapse. Operative mortality was 1.3%. In 26 cases (3.7%), mitral valve repair was unsuccessful and was converted to replacement. Of those successfully repaired, the 12-year survival rate, freedom from mitral reoperation, freedom from recurrent moderate or severe MR, and freedom from recurrent leaflet prolapse was 85.9%, 88.7%, 72.3%, and 89.0%, respectively. The significant predictors of recurrent MR were anterior leaflet prolapse, age, New York Heart Association class III or IV, left ventricular end-systolic dimension, no annuloplasty ring or band, and postoperative residual mild or greater MR.ConclusionsThe tourniquet technique is a simple and effective method to repair leaflet prolapse, with a low incidence of recurrent prolapse. The incidence of recurrent MR was high in the anterior leaflet prolapse group. Age, no annuloplasty ring or band, and residual MR were strong predictors of recurrent MR

Nitric Oxide-Mediated Modulation of Central Network Dynamics during Olfactory Perception.

Nitric oxide (NO) modulates the dynamics of central olfactory networks and has been implicated in olfactory processing including learning. Land mollusks have a specialized olfactory lobe in the brain called the procerebral (PC) lobe. The PC lobe produces ongoing local field potential (LFP) oscillation, which is modulated by olfactory stimulation. We hypothesized that NO should be released in the PC lobe in response to olfactory stimulation, and to prove this, we applied an NO electrode to the PC lobe of the land slug Limax in an isolated tentacle-brain preparation. Olfactory stimulation applied to the olfactory epithelium transiently increased the NO concentration in the PC lobe, and this was blocked by the NO synthase inhibitor L-NAME at 3.7 mM. L-NAME at this concentration did not block the ongoing LFP oscillation, but did block the frequency increase during olfactory stimulation. Olfactory stimulation also enhanced spatial synchronicity of activity, and this response was also blocked by L-NAME. Single electrical stimulation of the superior tentacle nerve (STN) mimicked the effects of olfactory stimulation on LFP frequency and synchronicity, and both of these effects were blocked by L-NAME. L-NAME did not block synaptic transmission from the STN to the nonbursting (NB)-type PC lobe neurons, which presumably produce NO in an activity-dependent manner. Previous behavioral experiments have revealed impairment of olfactory discrimination after L-NAME injection. The recording conditions in the present work likely reproduce the in vivo brain state in those behavioral experiments. We speculate that the dynamical effects of NO released during olfactory perception underlie precise odor representation and memory formation in the brain, presumably through regulation of NB neuron activity