A hyperbolic decay of subjective probability of obtaining delayed rewards

<p>Abstract</p> <p>Background</p> <p>Hyperbolic discounting of delayed and probabilistic outcomes has drawn attention in psychopharmacology and neuroeconomics. Sozou's evolutionary theory proposed that hyperbolic delay discounting may be totally attributable to aversion to a decrease in subjective probability of obtaining delayed rewards (SP) which follows a hyperbolic decay function. However, to date, no empirical study examined the hypothesis, although this investigation is important for elucidating the roles of impatience, precaution, and uncertainty aversion in delay discounting processes.</p> <p>Methods</p> <p>In order to (i) determine the functional form of the relation between delay until receipt and SP, and (ii) examine whether delay discounting is attributable to a decrease in SP, we assessed the subjects' SP and their delay and probability discounting. We examined the fitness of hyperbolic and exponential functions to the assessed SP, and relations between the SP, and delay/probability discounting, and subjective-probability discounting for delayed rewards.</p> <p>Results</p> <p>The results demonstrated (a) SP decayed hyperbolically as delay increases, (b) a decay of SP was associated with delay discounting, and (c) subjective-probability discounting did not significantly correlate with delay discounting.</p> <p>Conclusion</p> <p>Our results demonstrated (i) hyperbolic decay of SP is related to delay discounting, and (ii) delay discounting is, however, not attributable to precautious foresight in intertemporal choice. Further, a novel parameter of pure time preference is proposed.</p

Aging and Diversity of Medical Needs: Cost of illness of cerebrovascular disease in each prefecture of Japan

Background:&nbsp;Aging in Japan is advancing most rapidly in the world, and is expected to increase demand of medical services more in near future. Aging is uneven and progress of the aging varies from regions resulting in great differences in medical needs. In order to supply the needs for medical services, Japanese government developed “Regional Medical Vision”, which estimates the near future requirements for medical resources. However, this is a plan for redistribution of medical resources taking into only future changes of population composition based on current situation. In fact, each region has diversity of medical needs, and it is difficult to use average medical needs even if they are adjusted by population structures. In consideration of such situation, we tried to estimate the social burden of major diseases of each region in order to estimate the medical needs. We picked up cerebrovascular diseases (CVD, ICD10 code: I60 - I69) and dementia (ICD10code: F01, F03, G30), and calculated their social burden of all 47 prefectures in Japan that have great authority for health policy. Method:&nbsp;Modifying the COI method developed by Rice D, we newly defined and estimated C-COI of CVD (ICD10 code: I60 - I69) and dementia (ICD10code: F01, F03, G30). C-COI consists of five parts; direct cost (medical), morbidity cost, mortality cost, direct cost (long term care (LTC)) and informal care cost (family’s burden). Direct cost (medical) is medical cost of each disease. Morbidity cost is opportunity cost for inpatient care and outpatient care. Mortality cost is measured as the loss of human capital (human capital method). These three costs are known as components of original cost of illness by Rice D. Direct cost (LTC) is long term care insurance benefits. Family’s burden is “unpaid care cost” by family, relatives and friends in-home and in-community (opportunity cost). We calculated such costs at 2013/2014 using Japanese official statistics. Results:&nbsp;The total C-COI of CVD in Japan was about 6,177 billion JPY, the maximum was 621 billion JPY in Tokyo and the minimum was 33 billion JPY in Tottori (Tokyo/Tottori=18.8), whereas the total C-COI of dementia was 3,778 billion JPY, the maximum was 341 billion JPY in Tokyo and the minimum was 22 billion JPY in Tottori (Tokyo/Tottori=15.5). The C-COI per capita of CVD in Japan was about 48 thousand JPY, the maximum was 66 thousand JPY in Kagoshima and the minimum was 38 billion JPY in Saitama (Kagoshima/Saitama=1.7), whereas the total C-COI of dementia was 3,778 billion JPY, the maximum was 46 thousand JPY in Shimane and the minimum was 22 thousand JPY in Chiba (Shimane/Chiba=2.1). Conclusion:&nbsp;We substantiated a method to calculate the social burden of medical care and LTC care for each prefecture using C-COI methods. In both diseases, a large difference was found in total costs per capita and components ratio between prefectures. The situations of social burden of diseases has diversity among prefectures. When estimating the future medical needs of each region, it is necessary to take each regional condition into account

Multimodal Prediction of Cervical Lymph Node Metastasis and Recurrence in Oral Squamous Cell Carcinoma

Background/Aim: Oral squamous cell carcinoma (OSCC) is the most common malignancy in the head/neck region, and cervical lymph node (CLN) metastasis is a strong poor-prognosis factor. In addition, many patients with OSCC experience recurrence despite multidisciplinary treatment. We sought to identify factors associated with CLN metastasis and recurrence in patients with OSCC. Patients and Methods: We evaluated a total of 45 patients and 233 target CLNs. The longest diameter of the target CLN, the shortest diameter of the target CLN (LS), the area of the target CLN, and the relative computed tomography (CT) values of the target CLNs calculated based on the CT values of the internal jugular vein (LCT) were obtained from preoperative CT images, and the maximum standardized uptake values of the primary tumor (pSUV) and target CLN (nSUV) were obtained from preoperative 18F-fluorodeoxyglucose-positron emission tomography/CT images. We performed immunohistochemical staining for cytokeratin 13 (CK13) and 17 (CK17) on neck dissection tissues. Results: A discrimination equation was used that can predict CLN metastasis with a 92.2% discrimination rate using LS, LCT, pSUV, and nSUV. The CLNs were divided into discrimination and non-discrimination groups based on discriminant equations and CK13 and CK17 were used as the objective variables. A significantly higher recurrence rate was observed in the non-discrimination group (CK13: 5-year recurrence rate 28.6% vs. 64.3%, p<0.01; CK17: 5-year recurrence rate 28.0% vs. 76.0%, p<0.01). Conclusion: CLN metastases in OSCC can be assessed by combining preoperative imaging. The combined use of CK13 and CK17 expression with imaging findings offers an integrated approach to predict OSCC recurrence

Angina Simultaneously Diagnosed with the Recurrence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) mainly affects young adults and can have a potential impact on social functioning. As this syndrome is associated with endothelial dysfunction, the heart can be damaged via ischemia due to endothelial damage. This might potentially lead to heart failure, which accounts for approximately 20% of deaths among patients with ME/CFS. While cardiac ischemia is thought be a pathophysiologically important manifestation of this syndrome, this is not yet reported. Herein, we present a case of a young female with newly diagnosed vasospastic or microvascular angina and concurrent exacerbation of ME/CFS severity. Her anginal symptoms, including exertional chest pain and transient chest discomfort, mimicked those of ME/CFS but were relieved after the administration of a calcium channel blocker. We emphasize the possibility of concurrent angina and exacerbation of ME/CFS and the importance of detecting cardiac ischemia to avoid unfavorable outcomes

Zinc is a novel intracellular second messenger

Zinc is an essential trace element required for enzymatic activity and for maintaining the conformation of many transcription factors; thus, zinc homeostasis is tightly regulated. Although zinc affects several signaling molecules and may act as a neurotransmitter, it remains unknown whether zinc acts as an intracellular second messenger capable of transducing extracellular stimuli into intracellular signaling events. In this study, we report that the cross-linking of the high affinity immunoglobin E receptor (Fcɛ receptor I [FcɛRI]) induced a release of free zinc from the perinuclear area, including the endoplasmic reticulum in mast cells, a phenomenon we call the zinc wave. The zinc wave was dependent on calcium influx and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase activation. The results suggest that the zinc wave is involved in intracellular signaling events, at least in part by modulating the duration and strength of FcɛRI-mediated signaling. Collectively, our findings indicate that zinc is a novel intracellular second messenger

A Report on a Stargazing Session Conducted by Graduate and Undergraduate Students: Observing the Shapes of Moon and Saturn through Telescopes by Kindergarten Children

Aspiring secondary school science teachers must experientially learn the way of using a telescope and teaching star watching through a stargazing session. As a part of experiential activities, a stargazing session to observe the moon and Saturn was organized for 5-year-old kindergarten children on October 27, 2017, by graduate and undergraduate students; the session was conducted on the roof of building C of the Faculty of Education, Hiroshima University. The preparation for the session was a good opportunity for the students to review the knowledge that they had learned in class. The students interviewed the children about the shape of moon and Saturn immediately after they observed the planets. The two kinds of telescope used in star observing and the order of the planets that the children watched did not have much effect on the visibility of the planets. The results of interviews on the shape of the Moon indicated that the children understood the rough shape of the moon; however, they could not make an accurate understanding of the difference of the shape on the right and left sides. Furthermore, a possible effect of visual information, such as drawings, on the form of stars was confirmed.本研究の一部にJSPS科研費(JP26350235, JP17H00820) を使用した

Reproduction of the Antitumor Effect of Cisplatin and Cetuximab Using a Three-dimensional Spheroid Model in Oral Cancer

Background/Aim: Cancer research has been conducted using cultured cells as part of drug discovery testing, but conventional two-dimensional culture methods are unable to reflect the complex tumor microenvironment. On the other hand, three-dimensional cultures have recently been attracting attention as in vitro models that more closely resemble the in vivo physiological environment. The purpose of this study was to establish a 3D culture method for oral cancer and to verify its practicality. Materials and Methods: Three-dimensional cultures were performed using several oral cancer cell lines. Western blotting was used for protein expression analysis of the collected cell masses (spheroids), and H-E staining was used for structural observation. The cultures were exposed to cisplatin and cetuximab and the morphological changes of spheroids over time and the expression changes of target proteins were compared. Results: Each cell line formed spheroidal cell aggregates and showed enhancement of cell adhesion molecules over time. H-E staining showed tumor tissue-like structures specific to each cell line. Cisplatin showed concentration-dependent antitumor effects due to loss of cell adhesion and spheroid disruption in each cell line, while cetuximab exhibited antitumor effects that correlated with EGFR expression in each cell line. Conclusion: Spheroids made from oral cancer cell lines appeared to have tumor-like characteristics that may reflect their clinical significance. In the future, it may become possible to produce tumor spheroids from tissue samples of oral cancer patients, and then apply them to drug screening and to develop individualized diagnostic and treatment methods