190 research outputs found
Influence of myopotential interference on the Wavelet discrimination algorithm in implantable cardioverter-defibrillator
Background: Wavelet is a morphology-based algorithm for detecting ventricular tachycardia. The electrogram (EGM) source of the Wavelet algorithm is nominally programmed with the Can-RV coil configuration, which records a far-field ventricular potential. Therefore, it may be influenced by myopotential interference. Methods: We performed a retrospective review of 40 outpatients who had an implantable cardioverter-defibrillator (LCD) with the Wavelet algorithm. The percent-match score of the Wavelet algorithm was measured during the isometric chest press by pressing the palms together. We classified patients with percent-match scores below 70% due to myopotential interference as positive morphology change, and those with 70% or more as negative morphology change. Stored episodes of tachycardia were evaluated during the follow-up. Results: The number of patients in the positive morphology change group was 22 (55%). Amplitude of the Can-RV coil EGM was lower in the positive morphology change group compared to that in the negative group (3.9 +/- 1.3 mV vs. 7.4 +/- 1.6 mV, P=0.0015). The cut-off value of the Can-RV coil EGM was 5 mV (area under curve, 0.89). Inappropriate detections caused by myopotential interference occurred in two patients (5%) during a mean follow-up period of 49 months, and one of them received an inappropriate LCD shock. These patients had exhibited positive morphology change. Conclusions: The Wavelet algorithm is influenced by myopotential interference when the Can-RV coil EGM is less than 5 mV
The Hydrogen Burning Turn-off of RS Ophiuchi 2006
We report a coordinated multi-band photometry of the RS Oph 2006 outburst and
highlight the emission line free y-band photometry that shows a mid-plateau
phase at y ~ 10.2 mag from day 40 to day 75 after the discovery followed by a
sharp drop of the final decline. Such mid-plateau phases are observed in other
two recurrent novae, U Sco and CI Aql, and are interpreted as a bright disk
irradiated by the white dwarf. We have calculated theoretical light curves
based on the optically thick wind theory and have reproduced the observed light
curves including the mid-plateau phase and the final sharp decline. This final
decline is identified with the end of steady hydrogen shell-burning, which
turned out the day ~80. This turnoff date is consistent with the end of a
supersoft X-ray phase observed with Swift. Our model suggests a white dwarf
mass of 1.35 \pm 0.01 M_\sun, which indicates that RS Oph is a progenitor of
Type Ia supernovae. We strongly recommend the y-filter observation of novae to
detect both the presence of a disk and the hydrogen burning turn-off.Comment: to appear in ApJL, 4 pages including 4 figure
Distinct but interchangeable subpopulations of colorectal cancer cells with different growth fates and drug sensitivity
大腸がん細胞の増殖運命の違いと薬剤感受性 --その柔軟性を決めるメカニズム--. 京都大学プレスリリース. 2023-01-20.Dynamic changes in cell properties lead to intratumor heterogeneity; however, the mechanisms of nongenetic cellular plasticity remain elusive. When the fate of each cell from colorectal cancer organoids was tracked through a clonogenic growth assay, the cells showed a wide range of growth ability even within the clonal organoids, consisting of distinct subpopulations; the cells generating large spheroids and the cells generating small spheroids. The cells from the small spheroids generated only small spheroids (S-pattern), while the cells from the large spheroids generated both small and large spheroids (D-pattern), both of which were tumorigenic. Transition from the S-pattern to the D-pattern occurred by various extrinsic triggers, in which Notch signaling and Musashi-1 played a key role. The S-pattern spheroids were resistant to chemotherapy and transited to the D-pattern upon drug treatment through Notch signaling. As the transition is linked to the drug resistance, it can be a therapeutic target
Overexpression of c-Met/hepatocyte growth factor receptors in human prostatic adenocarcinoma.
Hepatocyte growth factor (HGF) and c-met proto-oncogene product (c-Met) have varied biological functions in different tissues and have been implicated in mitogenic, motogenic and morphogenic responses in both organ regeneration and carcinogenesis. Some studies have suggested that the overexpression of c-Met and epidermal growth factor receptor (EGFR) are associated with growth advantage, while transforming growth factor-beta receptor II (TGF beta R II) is associated with growth disadvantage of human prostatic adenocarcinoma. However, it is unclear if the expression of c-Met correlates with the expression of EGFR and TGF beta R II, and with the proliferative status of human prostatic adenocarcinoma. Using immunohistochemical staining with anti-c-Met (C-12), anti-EGFR (NCL-EGFR) and anti-TGF beta R II (L-21) antibodies, we determined the frequency of expression of c-MET, EGFR, and TGF beta R II respectively in a series of 134 radical prostatectomy specimens. We evaluated the relationship between the expression of these receptors and clinicopathological characteristics. Overall, c-Met immunostaining was detected in 54 of 134 (40.3%) cases, EGFR in 45 (33.6%) and TGF beta R II in 64 (48.4%). The overexpression of c-Met was significantly more common in poorly differentiated (P < 0.0001) and in the diffusely infiltrated specimens (P < 0.0005). In contrast, TGF beta R II was significantly overexpressed in the well differentiated specimens (P < 0.0001) and associated negatively with c-Met (P < 0.0001). Overall, these data suggest that c-Met/HGF receptor and TGF beta R II overexpression may be involved in the differentiation of human prostatic adenocarcinoma, c-Met with de-differentiation and TGF beta R II with differentiation.</p
Two-photon spectroscopy of core excitons in barium fluoride using synchrotron radiation and laser light
We have conducted two-photon spectroscopy of core excitons in BaF2. Synchrotron radiation and laser light were used for 5p core-electron excitation and Auger-free luminescence was detected as the signal. Two-photon excitation enables access to f and p orbitals that cannot be reached by one-photon excitation of electrons in p orbitals. It has been found that the spin-orbit splittings of 4f and 6p states of the Ba ion in BaF2 are 0.7 +/- 0.1 and 1.4 +/- 0.1 eV, respectively.</p
Field experiments in labor economics
In this thesis I show with three studies how field experiments can enhance our understanding of labor markets. Economists traditionally assume that individuals exclusively respond to monetary incentives. As a consequence, if workers have no prospect of future employment at the firm and pay is not contingent on their performance, a wage change should not affect effort. Some economists, however, have recognized that this narrow view of human motivation may severely limit our progress in understanding incentives. In Chapters 2 and 3, I investigate the role of psychological motives like the desire to reciprocate in the context of a real‐life work environment. The first experiment explores the impact of a wage increase on work performance when there is no economic reason for workers to change their effort. I find that workers reciprocate a generous wage with higher performance, particularly those workers who care about fairness and felt underpaid prior to the wage increase. The second experiment investigates the effects of a wage cut on performance when either all workers in a team or only some of them suffer the cut. I show that a general pay cut reduces performance, while a wage cut for only some of the workers reduces their performance more than twice as much. This finding demonstrates the powerful force of social comparison and the need to build the social nature of humans into economic theory. In Chapter 4, I examine the joint effects of monetary incentives and social interaction on work performance. Many jobs offer wage schemes that create positive or negative externalities on coworkers. Whether or not workers have the possibility to interact socially at work may distort the intended incentives of these schemes. I find that under relative incentives, when own effort imposes a negative externality on the coworker’s income, social interaction works against monetary incentives and leads to low performance due to collusion. However, the more workers differ in skills the less able they are to sustain collusive agreements.
In der vorliegenden Dissertation zeige ich anhand von drei Studien wie Feldexperimente unser Verständnis von Arbeitsmärkten verbessern können. Ökonomen gehen traditionell davon aus, dass Individuen ausschliesslich auf materielle Anreize reagieren. Wenn also Arbeitskräfte keine Aussicht auf eine langfristige Anstellung haben und deren Lohn nicht von der Leistung abhängt, dann sollte eine Lohnveränderung keinen Einfluss auf die Arbeitsleistung haben. Manche Ökonomen haben jedoch erkannt, dass diese Sichtweise des menschlichen Verhaltens beschränkt ist und unseren Fortschritt im Verständnis von Anreizen bremsen kann. In den Kapiteln 2 und 3 untersuche ich die Bedeutung von psychologischen Motiven wie Fairness oder Reziprozität in echten Arbeitsumgebungen. Das erste Experiment untersucht den Einfluss einer Lohnerhöhung auf die Arbeitsleistung, wenn Arbeitskräfte keinen ökonomischen Grund haben, ihren Arbeitseinsatz zu ändern. Diese Studie zeigt, dass Arbeitskräfte einen grosszügigen Lohn mit höherer Arbeitsleistung erwidern. Dies gilt besonders für diejenigen, die Fairness als wichtig empfinden und sich vor der Lohnerhöhung unterbezahlt fühlten. Das zweite Experiment untersucht die Wirkung einer Lohnkürzung auf die Arbeitsleistung, wenn entweder das ganze Team oder nur einen Teil davon betroffen ist. Diese Studie zeigt auf, dass eine generelle Lohnkürzung die Arbeitsleistung senkt, wohingegen eine Lohnkürzung nur für einzelne Arbeitskräfte deren Leistung um mehr als das Doppelte reduziert. Diese Erkenntnis unterstreicht die Bedeutung von sozialen Motiven und die Notwendigkeit einer Veränderung des Menschenbilds in der Ökonomie. In Kapitel 4 erforsche ich den gemeinsamen Einfluss von materiellen Anreizen und sozialer Interaktion auf die Arbeitsleistung. Viele Firmen bieten Lohnsysteme an, bei welchen die eigene Leistung vor‐ oder nachteilhafte Nebeneffekte auf das Einkommen der Arbeitskollegen hat. Soziale Interaktion am Arbeitsplatz kann dabei die Anreize dieser Lohnsysteme verzerren. Diese Studie findet heraus, dass bei Entlohnung der Arbeitskräfte durch Turnieranreize, d.h. wenn die eigene Leistung sich nachteilhaft auf das Einkommen der Arbeitskollegen auswirkt, soziale Interaktion die Anreize ausser Kraft setzt und zu geheimen Absprachen führt. Wenn hingegen Arbeitskräfte sehr unterschiedliche Fähigkeiten besitzen, dann sind geheime Absprachen schwieriger aufrecht zu halten
Carbon Ion Radiotherapy for Perupheral Stage1 Non-Small Cell Lung Cancer
The National Institute of Radiological Sciences in Chiba, Japan (NIRS) has highest number of patients with lung cancer treated with carbon ion beams in the world. This report describes the techniques and clinical trials that have been undertaken at NIRS and preliminary results of a current study on single-fraction irradiation. The data are compared to recent results for the treatment of peripheral stage I lung cancer from the literature
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