lanata

Krascheninnikovia lanata (Pursh) A. Meeuse & A. Smitwinterfatansérine laineuseCeratoides lanatacoulee N.E. of C.P.R. trestles, Lethbridgeamong sage brushSagebrushshrub, 1 foo

bronchialis

Saxifraga bronchialis Linnaeusspotted saxifrage;yellow-dotted saxifrage;yellow-spotted saxifrage;matted saxifragesaxifrage à pétales ponctuésWest of Lost Lakescree slope, facing east7000 fee

Measurement of alveolar bone mineral density (BMD) to evaluate chronic periapical lesions.

目的：歯槽骨の骨密度（bone mineral density, BMD）は、根尖病変の拡大と治癒の過程において変化する。DentalSCOPE（メディア、東京）は、歯槽骨のBMD値を計測するために開発された画像解析システムである。BMD値計測では、口内法デジタルＸ線撮影装置の機種による特性の違いが測定精度に影響する可能性がある。そのため本研究ではまず、輝尽性蛍光体（photo-stimulable phosphor, PSP）デジタル口内法Ｘ線撮影システムにおけるBMD計算キャリブレーションの方法を検討した。次に、根尖病変の大きさによるBMDの変化について実験的に検討した。 方法：三種類のPSPデジタル口内法Ｘ線撮影システム（以後、PSPシステムと略す）を使用してBMD値定量ファントムの口内法デジタルX線画像を撮影し、各PSPシステムに最適なソフトウェアパラメータ設定について検討した。続いて、乾燥下顎骨の根尖に実験的な模擬根尖病変を作成した。模擬病変が十分に大きくなるまで、根尖の骨を削除してＸ線撮影する作業を繰り返した。歯科用コーンビームCT（CBCT）画像上の根尖病変の大きさを計測してBMD値との相関を調べた。 結果：DentalSCOPEのパラメータ設定を最適化するためのキャリブレーション手順を実行しなかった場合、BMD値は使用したPSPシステムによって異なっていた。三種類のPSPシステム間のBMD値の違いは、イメージングシステム固有のキャリブレーションを適用することで最小限に抑えることができた。根尖周囲病変のBMD値に関して、病変の近遠心径とBMD値は中程度の相関を示した。頬舌の直径と病変の体積はBMD値と高い相関を示した。BMD値は歯根嚢胞のX線写真では観察が困難な小さな病変にも鋭敏に変化した。結論：歯槽骨のBMD値測定は、根尖周囲病変の段階を評価して歯内治療の予後を観察するのに有用と考える。Objectives : The bone mineral density (BMD) of alveolar bone should be changing following the growing and healing process of the lesion. The DentalSCOPE (Media Corporation, Tokyo, Japan) is an image analysis system developed to evaluate the BMD of alveolar bone. In this system, measurement accuracy may be aff ected by the individual characteristics of diff erent digital imaging systems. Therefore, this study aimed to examine calibration method for the BMD calculation in photo-stimulable phosphor (PSP) digital intraoral imaging systems. Then we performed an in-vitro study to compare the size of periapical lesions and their BMD. Methods : Intraoral digital radiographs of the standardized BMD phantoms were obtained using three PSP imaging systems. We studied the optimal software parameter for setting each PSP imaging system. Experimental pseudo-periapical lesions were created in the root apex of dried mandibles. We repeated the process of removing the bone and took images until the lesions were large enough. We examined whether the relationship exists between the size of periapical lesions in the dental CBCT images and BMD of periapical lesions or not. Results : Without a calibration to optimize the DentalSCOPEʼs parameter setting, the BMD values were diff erent depending on the PSP imaging systems used. The diff erences in the BMD value between three PSP imaging systems were minimized by application of the imaging system specifi c calibration. The mesio-distal diameter of the lesions and their BMD values showed a moderate correlation with each other. The bucco-lingual diameter and volume of the lesion showed a high correlation with the BMD. The BMD value responded sensitively to small lesions that were diffi cult to detect with a periapical radiograph. Conclusion : BMD measurement will be useful to evaluate the stage of periapical lesion and to observe the prognosis of endodontic treatmentjournal articl

Riviste di matematica e pubblico di insegnanti (18e – 20e secolo). Il ruolo euristico dell’eterogeneità dei mondi dell’insegnamento della matematica

Die Historiker interessieren sich für die Mechanismen der Zirkulation – ein integraler Bestandteil der Erforschung des Produktionsprozesses der Mathematik selbst – wovon der Unterricht eine besondere Form ist. Wir versuchen ein besseres Verständnis der Mathematik, wie sie von Akteuren aus verschiedenen Schulbereichen in Europa vom 18. bis zum 20. Jahrhundert praktiziert wurde, zu erlangen. Dazu analysieren wir Zeitschriften und wie sich diese an Lehrpersonen richten, welche redaktionellen Projekte verfolgt werden sowie deren Leser- und Autorschaft. Es zeigt sich, dass das Zielpublikum, d.h. die Lehrpersonen, in ihrer Vielfalt selbst zu Produzenten von mathematischem Wissen werden und in der Folge die traditionelle Trennung zwischen wissenschaftlichem und schulischem Wissen sowie zwischen wissenschaftlichen und schulischen Sphären in Frage stellen.Putting on their agenda the study of the various mathematical practices of a time, historians focused on the mechanisms of circulation – a part of the study of the production process of mathematics as such – of which teaching is one of the particular forms. By the study of journals addressed to teachers, their editorial projects, their readership and their authorship, we will try to grasp mathematics as practiced by the actors of different school spheres in the Europe of the 18th to 20th centuries. It appears that the diverse teacher audiences themselves become producers of the published mathematical knowledge, questioning the traditional partitions between scholarly knowledge and school knowledge, scholarly spheres and school spheres.Mettant à leur agenda l’étude des diverses pratiques mathématiques d’un temps, les historiens se sont intéressés aux mécanismes de circulation – partie prenante de l’étude du processus de production des mathématiques lui-même –, dont l’enseignement est une des formes particulières. En nous attachant au vecteur que sont les journaux adressés à des publics enseignants, à leurs projets éditoriaux, leurs lectorats et leurs autorats, nous chercherons à saisir au mieux les mathématiques telles qu’elles furent pratiquées par les acteurs de différentes sphères scolaires dans l’Europe du 18e au 20e siècle. Il apparait alors que les publics enseignants, dans leur diversité, deviennent eux-mêmes producteurs des savoirs mathématiques que donnent à lire les journaux, mettant en cause les partitions traditionnelles entre savoirs savants et savoirs scolaires, sphères savantes et sphères scolaires.Mettendo all’ordine del giorno lo studio delle diverse pratiche di matematica del passato, gli storici si sono interessati ai meccanismi di circolazione – che fanno parte del processo di produzione della matematica stessa – tra i quali l’insegnamento che ne è una forma particolare. Considerando in particolare il il vettore rappresentato dalle riviste di matematica  indirizzate ad un pubblico di insegnanti, ai loro progetti editoriali, ai loro lettori e ai loro autori, l’articolo cerca  di cogliere al meglio la matematica che fu praticata dagli attori delle diverse sfere scolastiche in Europa dal 18e al 20e secolo. Appare allora che il pubblico degli insegnanti, nella sua diversità, diventa a sua volta produttore della conoscenza matematica divulgata nelle riviste, mettendo in causa la partizione tradizionale fra conoscenza accademica e conoscenza scolastica