Basic properies of beam flatness analyzer (THEBES 7000)

癌の有力な治療法の1つである放射線治療はシステム全体の許容誤差が±5％と、正確な治療が要求されている。正確な線量を正確な場所に照射されなければならない。そのためには日頃から照射装置のQuality Control が重要である。Beam平坦度の測定はその中でも、重要な項目で1／6月の測定頻度が勧告されている。今回、市販のBeam Flatness Analyzer (7000型 THEBES) を使用する機会を得たので、その基礎的性能であるChamber 相互の感度のちがい、測定値の再現性、識別可能な最小線量について実験を行った。各項目とも誤差が非常に少なく、日常の使用に際してそのデータは十分信頼できるものであることがわかった。Lrradiation, which is one of the effective therapies to Cancer, is required to be accurate within ±5% of the tolerable error of the total system. An accurate dose has to be irradiated accurately at a target volume. For that Quality Control of the irradiation equipment is cotinually important. As the measurement of Beam Flatness is an important item, it is obligated to be measured once a week. In this paper as we have an opportunity to use a Beam Flatness Analyzer sold on a corporation of medical instrument, we experiment about the difference of sensitivity of mutual Chamber which is its basic property, the reproducibility of the measured score, and the minimum value of measuralbe dose. We find that the difference in every item is so small that its data is very reliable in a daily use

SALMONELLA TYPES IN ANIMALS IN SAPPORO II

A survey on Salmonella distribution was conducted in apparently healthy animals in and around Sapporo. The data are summarized as follows : 1. Salmonella was detected in 11 cases out of 355 (3.1%) dogs in Sapporo. Specimens were serological1y typed into 4 S. enteritidis, 6 S. typhi-murium and 1 S. thompson. S. thompson from dog is the first finding in Hokkaido. 2. From foxes, total 25 cultures of Salmonella were recovered in 19 cases out of 119 (16.0%). Sixteen of them were S. bareilly. Furthermore this is the first isolation from fox in Japan. The others are 6 S. typhi-murium and 3 S. enteritidis. Some cases showed incidence of 2 types. 3. No Salmonella was detected from 44 minks. 4. These Salmonella from dog and fox were detected from the mesenteric lymph node (70%), liver (30%), caecum contents (30%), spleen (20%) and kidney (3.3%). It is noticeable that no Salmonella was detected from the bile samples

Topic Jerk Detector: Detection of Tweet Bursts Related to the Fukushima Daiichi Nuclear Disaster

In recent disaster situations, social media platforms, such as Twitter, played a major role in information sharing and widespread communication. These situations require efficient information sharing; therefore, it is important to understand the trends in popular topics and the underlying dynamics of information flow on social media better. Developing new methods to help us in these situations, and testing their effectiveness so that they can be used in future disasters is an important research problem. In this study, we proposed a new model, “topic jerk detector.” This model is ideal for identifying topic bursts. The main advantage of this method is that it is better fitted to sudden bursts, and accurately detects the timing of the bursts of topics compared to the existing method, topic dynamics. Our model helps capture important topics that have rapidly risen to the top of the agenda in respect of time in the study of specific social issues. It is also useful to track the transition of topics more effectively and to monitor tweets related to specific events, such as disasters. We attempted three experiments that verified its effectiveness. First, we presented a case study applied to the tweet dataset related to the Fukushima disaster to show the outcomes of the proposed method. Next, we performed a comparison experiment with the existing method. We showed that the proposed method is better fitted to sudden burst accurately detects the timing of the bursts of the topic. Finally, we received expert feedback on the validity of the results and the practicality of the methodology