A robust and sparse K-means clustering algorithm

In many situations where the interest lies in identifying clusters one might expect that not all available variables carry information about these groups. Furthermore, data quality (e.g. outliers or missing entries) might present a serious and sometimes hard-to-assess problem for large and complex datasets. In this paper we show that a small proportion of atypical observations might have serious adverse effects on the solutions found by the sparse clustering algorithm of Witten and Tibshirani (2010). We propose a robustification of their sparse K-means algorithm based on the trimmed K-means algorithm of Cuesta-Albertos et al. (1997) Our proposal is also able to handle datasets with missing values. We illustrate the use of our method on microarray data for cancer patients where we are able to identify strong biological clusters with a much reduced number of genes. Our simulation studies show that, when there are outliers in the data, our robust sparse K-means algorithm performs better than other competing methods both in terms of the selection of features and also the identified clusters. This robust sparse K-means algorithm is implemented in the R package RSKC which is publicly available from the CRAN repository

RSKC: An R Package for a Robust and Sparse K-Means Clustering Algorithm

Witten and Tibshirani (2010) proposed an algorithim to simultaneously find clusters and select clustering variables, called sparse K-means (SK-means). SK-means is particularly useful when the dataset has a large fraction of noise variables (that is, variables without useful information to separate the clusters). SK-means works very well on clean and complete data but cannot handle outliers nor missing data. To remedy these problems we introduce a new robust and sparse K-means clustering algorithm implemented in the R package RSKC. We demonstrate the use of our package on four datasets. We also conduct a Monte Carlo study to compare the performances of RSK-means and SK-means regarding the selection of important variables and identification of clusters. Our simulation study shows that RSK-means performs well on clean data and better than SK-means and other competitors on outlier-contaminated data

Combined Use of a Solid-Phase Hexapeptide Ligand Library with Liquid Chromatography and Two-Dimensional Difference Gel Electrophoresis for Intact Plasma Proteomics

The intact plasma proteome is of great interest in biomarker studies because intact proteins reflect posttranslational protein processing such as phosphorylation that may correspond to disease status. We examined the utility of a solid-phase hexapeptide ligand library in combination with conventional plasma proteomics modalities for comprehensive profiling of intact plasma proteins. Plasma proteins were sequentially fractionated using depletion columns for albumin and immunoglobulin, and separated using an anion-exchange column. Proteins in each fraction were treated with a solid-phase hexapeptide ligand library and compared to those without treatment. Two-dimensional difference gel electrophoresis demonstrated an increased number of protein spots in the treated samples. Mass spectrometric studies of these protein spots with unique intensity in the treated samples resulted in the identification of high- and medium-abundance proteins. Our results demonstrated the possible utility of a solid-phase hexapeptide ligand library to reveal greater number of intact plasma proteins. The characteristics of proteins with unique affinity to the library remain to be clarified by more extensive mass spectrometric protein identification, and optimized protocols should be established for large-scale plasma biomarker studies

The learning in the practices of the students who care the disturbance of consciousness patients from the analysis of their process

意識障害患者を学生に受け持たせ，看護過程の展開の実習を行った．実習終了後の学生の学びを内容分析した結果，看護基礎教育で必須に学ばなければならない清潔などの基本的技術項目や合併症の予防や，意識障害患者に必要な観察や回復支援方法やその大切さを学んでいた．さらに，モデリングとしての看護師の実施するケアの気づきや，学習後の充実感や達成感，患者が回復する事の喜びなどがあった．また，コミュニケーションや状態把握の難しさも学びとして表現していた．このように，意識障害患者を受け持つことで，多くの学習内容を学べることが明らかとなった．We make my students care the disturbance of consciousness patients. This study examines their practice developments by watching their process and analyzing their reports. They learned the followings : （１）The basic technical items（ex. the importance of the cleaning）and the prevention of the complication. （２）How to observe and support the disturbance of consciousness patient. （３）The existence of the nurses as modeling. （４）the emotional reactions such as the fulfillment, the accomplishment and the pleasure after caring and learning. （５）The difficulty to communicate with the patients and to grasp the situations. This result shows how necessary the students care the disturbance of consciousness patients because they learn many points

トクシマ ケンナイ ノ カンゴ ショクイン コウド ジンザイ イクセイ ケンシュウ スイシン ジギョウ ニオケル トクテイ コウイ ニ カカル ジッタイ チョウサ

The purpose of this survey was to determine nurse administrators and hospital directors’ perspectives about nurses’ abilities in performing specific medical practices in hospitals in Tokushima Prefecture. The nurse administrators and hospital directors of all hospitals （１１３ hospitals） in Tokushima Prefecture were invited to respond to a survey questionnaire by mail posted during the period between February and March of ２０１５. Responses were received from ４６ nurse administrators （response rate, ４１％） and ３８ hospital directors （response rate, ３４％）. The obtained data were analyzed using descriptive statistics and the narrative descriptions summarized. Majority of responses from nurse administrators and hospital directors were accepting that nurses have responsibilities for administering medicines such as tranquilizers, anti-anxiety and anticonvulsant drugs. This result was not affected by the size of the hospital, in which fifty four percent （５４％） of respondents were from hospitals with less than １００ beds. In Japan, only hospitals with １００ beds or more may have procedures involving highly invasive treatments. Because of this, many of the respondents answered “not applicable” to statements in the questionnaire which were related to invasive treatments. Recruitment of nurses, strategies to cope with accidents and education curriculum were important concerns of nurse administrators and hospital directors which remain to be answered in future investigations

臨地実習での学生自己評価 : 興味ある課題導入の有無による比較

臨地実習での学びを効果的にするために，３年課程３年次学生を対象に臨地実習固有の学習内容を用いた学生自己評価を継続しているが，自己評価得点は，実習開始前から中期にかけて上昇しても，中期から終了時には上昇しない傾向が続いた．そのため，成人看護学臨地実習（急性期）では，２００３年度後期に学生の興味・関心のあるテーマを課題学習として導入することを試みた．課題学習を導入した２００３年度後期（３６人）と導入しなかった２００１年度後期（３４人）の自己評価得点の差を統計的に検定することにより，課題学習の効果を検討した．その結果，以下の結果が得られた． ① 課題学習のテーマを決定する過程において，学生は，自己の学習状況を振り返り，整理することができた． ② 終了時の自己評価では，課題学習を導入しなかった２００１年度では４．０点以上の高得点の項目が２０項目であったのに対し，課題学習を導入した２００３年度では４０項目もあり，学生は学習内容に到達したと高く評価していた． これらのことより，興味・関心のあるテーマを課題学習として導入することは，学生の自発性を高め，学習内容に対する学生の到達度の認識を高める可能性があると考えられた．Objective : The purpose of this study was to assess the nursing students' recognitions of their achievement degrees for their educational goals in the clinical practices and discuss the effect of setting students the assignments of themes in which they had interested in the clinical practices. Methods : We used the self-evaluation questionnaire（６２ questions）. Self-evaluation was performed three times ; the first was before the clinical practice, at the middle point of the clinical practice and after the clinical practice. And we set the students assignments in which they had interested in the clinical practices at the middle point in２００３．And we didn't set them in２００１．Then we compared２００３with２００１，and we tested for equality between two means（p＜０．０５）． Results : １．The students assessed their clinical practices when they decided their own themes of assignments. ２．In the final evaluation, the students recognized they achieved their educational goals in４０items in２００３， though there were only２０items in２００１． Conclusion : These results suggest that it may be effective to set the students assignments of themes in which they had interested and that their arrival degrees may be raised by these programs

Learning of the students who have undertaken the patients necessitating rehabilitation

運動機能障害や意識レベルの障害があり，リハビリテーション看護の必要な患者を受け持った学生の実習終了後のレポートより，学生の学びを抽出し，内容分析を行った．その結果，２０３コードが抽出でき，３９サブカテゴリー，１０カテゴリーに分類できた．その内容は『リハビリテーション看護の方法の理解と必要性の自覚』，『患者の状況・把握の重要性と判断の難しさ』，『リハビリテーションの必要な患者の思い』，『看護師としての役割の自覚』，『看護のやりがいの実感』，『医療者の連携の重要性』，『家族への援助の必要性』，『コミュニケーションの重要性と難しさ』，『安全確保の重要性と難しさ』，『説明・指導・教育の重要性と難しさ』であった．この中で『リハビリテーションの必要な患者の思い』，『看護のやりがいの実感』，『安全確保の重要性と難しさ』，の３つが，リハビリテーション看護の必要な，運動機能障害や意識レベルの障害がある患者についての特徴的な学びであることがわかった．The learning of the students who experienced rehabilitation nursing of patients having disturbance of motility and/or impairment of consciousness was analyzed from their reports after the clinical practice. As the result, ２０３ codes were extracted and classified into ３９ sub categories and １１ categories. The categories were “understanding of the method of the rehabilitation nursing and consciousness of its necessity”, “importance of the grasp and difficulty of the judgment of the patient situation”, “thought of the patients who need rehabilitation”, “consciousness of the role as a nurse”, “necessity of the assist to the family”, “actual feeling of worth doing of the nursing”, “importance of the cooperation of the medical person”, “importance and difficulty of the communication”, “importance and difficulty of safety ensuring”, “importance and difficulty of explanation, guidance and education”, and “others”. It was found that the knowledge obtained through the rehabilitation nursing was mainly characterized with “importance of safety ensuring”, “thought of the patients”, and “actual feeling of worth doing of the nursing”

Development of a new method for assessing otolith function in mice using three-dimensional binocular analysis of the otolith-ocular reflex

In the interaural direction, translational linear acceleration is loaded during lateral translational movement and gravitational acceleration is loaded during lateral tilting movement. These two types of acceleration induce eye movements via two kinds of otolith-ocular reflexes to compensate for movement and maintain clear vision: horizontal eye movement during translational movement, and torsional eye movement (torsion) during tilting movement. Although the two types of acceleration cannot be discriminated, the two otolith-ocular reflexes can distinguish them effectively. In the current study, we tested whether lateral-eyed mice exhibit both of these otolith-ocular reflexes. In addition, we propose a new index for assessing the otolith-ocular reflex in mice. During lateral translational movement, mice did not show appropriate horizontal eye movement, but exhibited unnecessary vertical torsion-like eye movement that compensated for the angle between the body axis and gravito-inertial acceleration (GIA; i.e., the sum of gravity and inertial force due to movement) by interpreting GIA as gravity. Using the new index (amplitude of vertical component of eye movement)/(angle between body axis and GIA), the mouse otolith-ocular reflex can be assessed without determining whether the otolith-ocular reflex is induced during translational movement or during tilting movement