57 research outputs found

    On the Performance Evaluation of Action Recognition Models on Transcoded Low Quality Videos

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    In the design of action recognition models, the quality of videos in the dataset is an important issue, however the trade-off between the quality and performance is often ignored. In general, action recognition models are trained and tested on high-quality videos, but in actual situations where action recognition models are deployed, sometimes it might not be assumed that the input videos are of high quality. In this study, we report qualitative evaluations of action recognition models for the quality degradation associated with transcoding by JPEG and H.264/AVC. Experimental results are shown for evaluating the performance of pre-trained models on the transcoded validation videos of Kinetics400. The models are also trained on the transcoded training videos. From these results, we quantitatively show the degree of degradation of the model performance with respect to the degradation of the video quality.Comment: 10 page

    Lumbar Spinal Stenosis Has a Negative Impact on Quality of Life Compared with Other Comorbidities: An Epidemiological Cross-Sectional Study of 1862 Community-Dwelling Individuals

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    Lumbar spinal stenosis (LSS) is common in the elderly. However, there have been few reports on its impact on quality of life (QoL) in community-dwelling individuals. The purpose of this study was to clarify how symptomatic LSS affects QoL at the community level. A total of 1862 people (697 males and 1165 females, most subjects were between 40 and 85 y.o.) agreed to participate and were interviewed. The presence of symptomatic LSS was assessed by a specially designed questionnaire. The Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) was also administered. In addition, the presence of comorbid conditions that affect QoL, such as osteoarthritis of the knee and hip, cardiovascular disease, cerebrovascular disease, or respiratory disease, was also analyzed. The prevalence of symptomatic LSS gradually increased with age. Furthermore, the presence of symptomatic LSS had a strong negative effect on all 8 physical and mental domains and the physical component summary (PCS) (OR: 1.547–2.544) but not the mental component summary (MCS). In comparison with comorbid conditions, LSS had a much stronger negative impact on health-related QoL (HR-QoL). The current study confirmed that the presence of symptomatic LSS might have a strong negative influence on HR-QoL in the community setting

    The impact of self-shielded cyclotron operation on small-animal PET/CT equipment installed nearby, on the floor just above

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    Purpose : The purpose of this study was to evaluate the impact of a cyclotron on small-animal PET equipment installed directly above the cyclotron. Methods : The cyclotron equipment was HM-12, which has two targets, and the PET/CT equipment was Inveon. The equipment was installed in conformity to Japanese law and regulations. Before installation of the PET/CT equipment, the radiation dose, radio waves, and static and fluctuating magnetic fields were measured at the position where it would be placed, both when the cyclotron was in use and when it was not in use. After installation of the PET/CT, natural background and emission counts were measured at the same place under the same conditions. Results : An increase of radiation dose was observed when the target nearest the PET equipment was used. There were no distinct effects of radio waves or static and fluctuating magnetic fields. A significant increase of emission counts, approximately 300 cpm, was observed when the nearest target was used. Conclusions : Though radio waves and static and fluctuating magnetic fields generated by running cyclotron had no influence, a significant increase in emission count was observed. Careful attention should be paid to this influence when very low-radioactivity PET measurements are done

    Predicting Therapeutic Effects using PET/CT

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    This study investigated the usefulness of [18F]-3’-deoxy-3’-fluorothymidine (18F-FLT) and [18F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging for predicting the therapeutic efficacy of non-small cell lung cancer (NSCLC) irradiation at an early stage after radiation treatment. Mice were xenografted with the human lung adenocarcinoma line A549 or large cell lung cancer line FT821. Tumour uptake of 18F-FLT and 18F-FDG was imaged using PET/CT before and 1 week after irradiation. In A549 tumours, 18F-FLT uptake was significantly decreased, and 18F-FDG uptake was unchanged post-irradiation compared with pre-irradiation. In FT821 tumours, uptake of both 18F-FLT and 18F-FDG uptake was substantially decreased post-irradiation compared with pre-irradiation. In both xenografts, tumour volumes in the irradiated groups were significantly decreased compared with those in the control group. 18F-FLT is expected to contribute to individual NSCLC therapy because it accurately evaluates the decrease in tumour activity that cannot be captured by 18F-FDG. 18F-FDG may be useful for evaluating surviving cells without being affected by the inflammatory reaction at an extremely early stage, approximately 1 week after irradiation. Combined use of 18F-FLT and 18F-FDG PET/CT imaging may increase the accurate prediction of radiotherapy efficacy, which may lead to improved patient outcomes and minimally invasive personalised therapy

    PET/CTを用いたマウス骨格筋インスリン抵抗性の評価

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    Measuring glucose uptake in the skeletal muscle in vivo is an effective method to determine glucose metabolism abnormalities as the skeletal muscle is the principal tissue responsible for glucose disposal and is a major site of peripheral insulin resistance. In this study, we investigated the pathological glucose metabolism dynamics of the skeletal muscle of C57BL/6J mice in a noninvasive and time-sequential manner using positron emission tomography/computed tomography (PET/CT), an imaging technique that uses radioactive substances to visualize and measure metabolic processes in the body, with [18F]-fluoro-2-deoxy-D-glucose (FDG). FDG-PET/CT imaging revealed that insulin administration and exercise load significantly increased FDG accumulation in the skeletal muscle of C57BL/6J mice. FDG accumulation was lower in the skeletal muscle of 14-week-old db/db diabetic model mice exhibiting remarkable insulin resistance compared to that of 7-week-old db/db mice. Based on the continuous observation of FDG accumulation over time in diet-induced obese (DIO) mice, FDG accumulation significantly decreased in 17-week-old mice after the acquisition of insulin resistance. Although insulin-induced glucose uptake in the skeletal muscle was markedly attenuated in 20-week-old DIO mice that had already developed insulin resistance, exercise load effectively increased FDG uptake in the skeletal muscle. Thus, we successfully confirmed that glucose uptake accompanied by insulin administration and exercise load increased in the skeletal muscle using PET-CT. FDG-PET/CT might be an effective tool that could noninvasively capture the chronological changes of metabolic abnormalities in the skeletal muscle of mice

    Exposure to high solar radiation reduces self-regulated exercise intensity in the heat outdoors

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    High radiant heat load reduces endurance exercise performance in the heat indoors, but this remains unconfirmed in outdoor exercise. The current study investigated the effects of variations in solar radiation on self-regulated exercise intensity and thermoregulatory responses in the heat outdoors at a fixed rating of perceived exertion (RPE). Ten male participants completed 45-min cycling exercise in hot outdoor environments (about 31 °C) at a freely chosen resistance and cadence at an RPE of 13 (somewhat hard). Participants were blinded to resistance, pedal cadence, distance and elapsed time and exercised at three sunlight exposure conditions: clear sky (mean ± SD: 1072 ± 91 W·m−2; HIGH); thin cloud (592 ± 32 W·m−2; MID); and thick cloud (306 ± 52 W·m−2; LOW). Power output (HIGH 96 ± 22 W; MID 103 ± 20 W; LOW 108 ± 20 W) and resistance were lower in HIGH than MID and LOW (P < .001). Pedal cadence was lower, the core-to-skin temperature gradient was narrower, body heat gain from the sun (SHG) was greater and thermal sensation was higher with increasing solar radiation and all variables were different between trials (P < .01). Mean skin temperature was higher in HIGH than MID and LOW (P < .01), but core temperature was similar between trials (P = .485). We conclude that self-regulated exercise intensity in the heat outdoors at a fixed RPE of somewhat hard is reduced with increasing solar radiation because of greater thermoregulatory strain, perceived thermal stress and SHG. This suggests that reduced self-selected exercise intensity during high solar radiation exposure in the heat may prevent excessive core temperature rise.PostprintPeer reviewe

    A new quantitative index in the diagnosis of Parkinson syndrome by dopamine transporter single photon emission computed tomography

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    Objective Dopamine transporter single-photon emission computed tomography (DAT SPECT) has been widely used to diagnose Parkinson syndrome. Using the standardized uptake value (SUV) of DAT SPECT, we propose “functional dopamine transporter volume (f-DTV)” as a new quantitative index to evaluate the three-dimensional volume of functional dopamine transporters and assess its diagnostic ability in differentiating dopaminergic neurodegenerative diseases (dNDD) from non-dNDD. Methods Seventy-nine patients were enrolled (42 dNDD, 37 non-dNDD; 38 men; age, 24–88 years). We analyzed seven quantitative indices. The specific binding ratio (SBR) was calculated using a program specialized for DAT SPECT (SBR_Bolt). The SUVmax, SUVpeak, and SUVmean were calculated using a quantification program for bone SPECT. SBR_SUV was calculated by dividing striatal SUVmean by the average of background SUVmean. The cutoff value of the active dopamine transporter level was examined using three methods (threshold of 40% of SUVmax, SUV 2, and SUV 3) to calculate the active dopamine transporter volume (ADV). The f-DTV was calculated by multiplying ADV and SUVmean. We assessed the correlations between SBR_Bolt and SBR_SUV, and compared the mean value of each index between the dNDD and non-dNDD groups. The abilities of SBR_Bolt, SBR_SUV, SUVmax, SUVpeak, SUVmean, ADV, and f-DTV in differentiating dNDD from non-dNDD were determined by the area under the receiver operating curve (AUC) generated by the receiver operating characteristics analysis. Results The SBR_Bolt and SBR_SUV highly correlated each other (r = 0.71). The cutoff value of the active dopamine transporter level was determined as SUV 3. All seven quantitative indices showed lower values in the dNDD group than in the non-dNDD group, and the difference between the two groups was statistically significant (p<0.05). Sensitivity, specificity, and AUC of f-DTV were slightly lower than those of SBR_Bolt (71%, 79%, and 0.81, respectively, for f-DTV, and 81%, 84%, 0.88, respectively, for SBR_Bolt). The difference in AUC between f-DTV and SBR_Bolt was not statistically significant. Conclusions This study demonstrates the utility of f-DTV as a novel quantitative index for evaluating the three-dimensional volume of functional dopamine transporters, and that f-DTV has almost the same diagnostic ability to differentiate dNDD from non-dNDD using DAT SPECT

    MONITORING ANAPLASTIC THYROID CANCER MODELS BY PET/CT

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    Anaplastic thyroid carcinoma (ATC) is a rare type of thyroid carcinoma with a poor prognosis. Thus, suitable preclinical tumor models are required for the development of new ATC therapies. In the present study, orthotopic tumor xenograft models were established using ATC cell lines and SCID mice, and tumor invasion and the effects of anticancer drugs were evaluated using positron emission tomography/computed tomography (PET/CT) to repeatedly and non-invasively monitor these models. Three ATC cell lines (8305c, 8505c, and ACT-1) were used. Their sensitivities to two anticancer drugs (paclitaxel and lenvatinib) were investigated. The 8505c cell line was orthotopically implanted into SCID mice, which were then divided into three groups: no chemotherapy, paclitaxel (5 mg/kg, administered intraperitoneally, every week), and lenvatinib (5 mg/kg, oral route, every day) groups. PET/CT was performed and tumor growth and the effects of anticancer drugs based on tumor volume and fludeoxyglucose (FDG) uptake were evaluated. 8505c cells exhibited the highest sensitivity to the anticancer drugs. In mice implanted with 8505c cells, continuous increases in FDG uptake associated with tumor growth were detected on PET/CT in the group that received no chemotherapy. The tumor volume and FDG uptake increased by 91.5- and 2.4-fold, respectively, within 2 weeks. The increase observed in tumor volume was 26.9- and 12.2-fold in the paclitaxel and lenvatinib groups, respectively, within 2 weeks. Furthermore, the increase in FDG uptake was 1.8-fold and 1.6-fold in the paclitaxel and lenvatinib groups, respectively, within 2 weeks. In our orthotopic SCID mouse model, tumor growth and the effects of anticancer drugs were repeatedly and non-invasively monitored using PET/CT. The present method is useful for the development of new ATC treatments

    Profissionais da psicologia no acolhimento de mulheres em situação de violência: Estudo de revisão sistemática

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    A violência contra a mulher é um tema relevante na área da saúde, considerando o recente aumento significativo no número de casos registrados. Este estudo teve por objetivo realizar uma revisão sistemática da literatura sobre o atendimento e acolhimento, por parte de profissionais da psicologia, para mulheres vítimas de violências. Foi utilizando o método PRISMA, consultando artigos desenvolvidos no Brasil, publicados na base de dados Período CAPES, entre 2000 e 2020. Entre 51 artigos encontrados inicialmente, 43 foram revisados segundo o escopo da pesquisa, dos quais 13 foram incluídos nesta revisão. A pesquisa realizada permitiu identificar categorias que entendem o quanto a violência contra mulheres é prejudicial em suas diversas formas de manifestação. Além disso, há algumas recomendações e estudos sobre qual a melhor forma de acolher as vítimas, mas não há documentos ou formas de padronização de modalidades deste tipo. Conclui-se pela importância da instrumentalização para a prática profissional diante desses casos
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