Out-of-time-order correlators in quantum mechanics

The out-of-time-order correlator (OTOC) is considered as a measure of quantum chaos. We formulate how to calculate the OTOC for quantum mechanics with a general Hamiltonian. We demonstrate explicit calculations of OTOCs for a harmonic oscillator, a particle in a one-dimensional box, a circle billiard and stadium billiards. For the first two cases, OTOCs are periodic in time because of their commensurable energy spectra. For the circle and stadium billiards, they are not recursive but saturate to constant values which are linear in temperature. Although the stadium billiard is a typical example of the classical chaos, an expected exponential growth of the OTOC is not found. We also discuss the classical limit of the OTOC. Analysis of a time evolution of a wavepacket in a box shows that the OTOC can deviate from its classical value at a time much earlier than the Ehrenfest time.Comment: 30 pages, 13 figure

Localized knowledge spillovers and patent citations: A distance-based approach

We develop a new approach to localized knowledge spillovers by incorporating the concept of control patents (Jaffe, Trajtenberg and Henderson 1993) into the distance-based test of localization (Duranton and Overman, 2005). Using microgeographic data, we identify localization distance while allowing for cross-boundary spillovers, unlike the existing literature where the extent of localized knowledge spillovers is detected at the state or metropolitan statistical area level. We revisit the recent debate by Thompson and Fox-Kean (2005) and Henderson, Jaffe and Trajtenberg (2005) on the existence of localized knowledge spillovers, and find solid evidence supporting localization, even when finer controls are used.

シコク チュウオウブ ササガタニ チイキ ニオケル チチブ ホクタイ ノ チシツ コウゾウ

The Sasagatani fault in central Shikoku was considered to be a tectonic boundary between the Sanbagawa high-P/T metamorphic belt and the Chichibu non-high-P/T belt. Metamorphic minerals of the greenstones around the Sasagatani fault are examined. Alkali amphibole, alkali pyroxene, actinolite, stilpnomelane and pumpellyite are found not only on the north side of the fault, but also on the south side. Strata around the Sasagatani fault have undergone the pumpellyite-actinolite facies metamorphism. Thus, the Sasagatani fault is not an upper boundary fault of the Sanbagawa metamorphic rocks. The Nanokawa thrust occurs in the Jurassic accretionary complexes of the Northern Chichibu Terrain in the Sasagatani Area. The greenstones of the hanging wall of the thrust have undergone the pumpellyite-actinolite facies metamorphism, whereas those of the footwall have undergone the prehnite-pumpellyite facies metamorphism. The Nanokawa thrust is a large overthrust, which has a different metamorphic grade between the hanging wall and footwall. The thrust is probably a southern boundary of the Jurassic accretionary deposits which have undergone the Sanbagawa metamorphism

Male Pheromones Induce Ovulation in Female Honeycomb Groupers (Epinephelus merra): A Comprehensive Study of Spawning Aggregation Behavior and Ovarian Development

This study characterizes the spawning phenomena of the honeycomb grouper (Epinephelus merra), which is a lunar-synchronized spawner that spawns a few days after full moon. To elucidate the aggregation characteristics of wild honeycomb groupers, the numbers of males and females at the spawning grounds were counted before and after the full moon. Approximately 20 males were consistently observed at the spawning grounds throughout the study period. Females appeared several days after full moon and rapidly increased in number, peaking four days after full moon (41 individuals). The maturation status of the females aggregating at the spawning grounds was investigated. The gonadosomatic index increased rapidly three days after full moon, and ovulation was confirmed. Individuals with ovulatory eggs were present for three days, after which the number of females at the spawning grounds decreased. Additionally, the role of males in final oocyte maturation (FOM) and ovulation in females during the spawning phase was investigated in captivity. FOM was induced in females reared in water with mature males, suggesting that male pheromones in the water induced FOM via activation of the hypothalamic–pituitary–gonadal axis. This suggests that spawning at the natural spawning grounds was the result of male–female interactions via pheromones

Improvement of orthoptic students’ self-evaluation through repeated practice with rubric-based assessments

The discipline of orthoptics covers a wide range of ophthalmological examinations and generates supports for visually disabled persons; consequently, orthoptic educators are continually trying to improve practical training. One problem is students’ inadequate abilities to self-evaluate and consistency among teacher evaluations. In the United States of America, rubric assessments have been used widely, from elementary through higher educational levels, since the late 1970’s. Because a rubric contains the explicit and descriptive criteria for scoring, assessments with rubric can help students and instructors consistently assess student performance. In a previous study, rubric assessments for off-campus clinical orthoptic internships were found useful in standardizing evaluations among multiple instructors. However, there have been no empirical studies on the long-term effects of orthoptic training with rubrics. While writing accurate reports on the practice is important for acquisition of clinical skills through practical course, students cannot obtain report-writing skills without accurate self-evaluation of their own reports. In this study, to investigate the long-term effects of rubric-based training, we repeated practice-assessment-feedback cycles for nine weeks using rubrics, and analyzed the observed disparities between self- and teacher-generated scores over time. All study procedures were performed in-house. We found that, over time, the disparities between the students’ and teachers’ scores decreased significantly, suggesting that students’ self-evaluation accuracy improved through repeated use of rubric. The improvement was category-dependent and larger in students with lower performance. These results indicate the advantages of repeating rubric-based formative assessments in orthoptic practices

The Sarin-like Organophosphorus Agent bis(isopropyl methyl)phosphonate Induces Apoptotic Cell Death and COX-2 Expression in SK-N-SH Cells

Organophosphorus compounds, such as sarin, are highly toxic nerve agents that inhibit acetylcholinesterase (AChE), but not cholinesterase, via multiple mechanisms. Recent studies have shown that organophosphorus compounds increase cyclooxygenase-2 (COX-2) expression and induce neurotoxicity. In this study, we examined the toxicity of the sarin-like organophosphorus agent bis(isopropyl methyl)phosphonate (BIMP) and the effects of BIMP on COX-2 expression in SK-N-SH human neuroblastoma cells. Exposure to BIMP changed cell morphology and induced caspase-dependent apoptotic cell death accompanied by cleavage of caspase 3, caspase 9, and poly (ADP-ribose) polymerase (PARP). It also increased COX-2 expression, while pretreatment with a COX inhibitor, ibuprofen, decreased BIMP-dependent cell death and COX-2 expression in SK-N-SH cells. Thus, our findings suggest that BIMP induces apoptotic cell death and upregulates COX-2 expression

Endocrine Regulation of Maturation and Sex Change in Groupers

Groupers are widely distributed in tropical and subtropical areas worldwide, are key species to coastal ecosystems, and valuable fishery targets. To facilitate artificial seed production technology for grouper aquaculture, the mechanisms of reproduction and gonad development are being elucidated for these important species. In addition, since groupers are sexually dimorphic fish with female-first maturity (protogynous hermaphrodite fish), research is being conducted to clarify the ecological mechanism of sex change and their reproductive physiology, focusing on the endocrine system. In recent years, research on groupers has also been conducted to understand changes in the coastal environment caused by ocean warming and man-made chemicals. However, due to difficulties associated with conducting research using wild populations for breeding experiments, knowledge of the physiology and ecology of these fish is lacking, especially their reproductive physiology. In this review, we present information on the reproductive physiology and endocrinology of groupers obtained to date, together with the characteristics of their life history