Perturbation approach to the Feller property for non-local operators (Stochastic Analysis of Jump Processes and Related Topics)

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Stability of the Feller property for non-local operators under bounded perturbations

It is known that the Feller property of a semigroup is stable under a bounded perturbation of the infinitesimal generator. Applying this, we derive the Feller property for a class of integro-differential operators including symmetric stable-like processes

Solvent Extraction of DNA with a Hydrolysable Double-chain Surfactant

A cationic lipophilic surfactant with two hydrolysable groups, di(1-octadecyloxycarbonylmethyl)dimethylammonium chloride, was synthesized and solvent extraction of deoxyribonucleotide (DNA) into organic solution (isooctane/1-octanol) with it as an extractant was examined. Not only a forward extraction of DNA into the organic phase but also back extraction into the aqueous phase (pH9) at room temperature proceeded efficiently. The forward extraction is promoted by electrostatic interactions of the surfactant and DNA and the back extraction is exclusively caused by hydrolysis of the surfactant to a non-surfactant.ArticleSEPARATION SCIENCE AND TECHNOLOGY. 44(2):466-475 (2009)journal articl

Ordered Counterfactual Explanation by Mixed-Integer Linear Optimization

Post-hoc explanation methods for machine learning models have been widely used to support decision-making. One of the popular methods is Counterfactual Explanation (CE), also known as Actionable Recourse, which provides a user with a perturbation vector of features that alters the prediction result. Given a perturbation vector, a user can interpret it as an "action" for obtaining one's desired decision result. In practice, however, showing only a perturbation vector is often insufficient for users to execute the action. The reason is that if there is an asymmetric interaction among features, such as causality, the total cost of the action is expected to depend on the order of changing features. Therefore, practical CE methods are required to provide an appropriate order of changing features in addition to a perturbation vector. For this purpose, we propose a new framework called Ordered Counterfactual Explanation (OrdCE). We introduce a new objective function that evaluates a pair of an action and an order based on feature interaction. To extract an optimal pair, we propose a mixed-integer linear optimization approach with our objective function. Numerical experiments on real datasets demonstrated the effectiveness of our OrdCE in comparison with unordered CE methods.Comment: 20 pages, 5 figures, to appear in the 35th AAAI Conference on Artificial Intelligence (AAAI 2021

Postmortem and helminthological examination of seabirds killed by oil spilled at Ishikari, Hokkaido, Japan, in November 2004

Postmortems and helminthological examinations were performed on beached seabirds killed by oil spilled from a grounded freighter at Ishikari, Hokkaido, Japan in November 13, 2004. The carcasses were covered with crude oil, but they had adequate subcutaneous fat levels. Gross pathological findings consisting of gastric ulcers, pulmonary edema, enlarged spleens and blackish liquid contents in the digestive tracts suggested that they had a rapid progression to death caused by a loss of ascending force, hypothermia and dehydration. Although the visceral organs had degenerated, no direct evidence of mortality caused by ingesting oil was observed. However, extensive acute inflammatory reactions caused by large numbers of mature and immature nematodes (Contracaecum rudolphii) deeply penetrating the gastric walls was observed in two of the birds. Helminthological investigations were conducted on 21 birds from six species, namely: Phalacrocorax capillatus, Aythya marila, Cerorhinca monocerata, Synthliboramphus antiquus, Aethia cristatella, and Brachyramphus perdix. Thirteen helminth species were obtained and identified, including eight nematodes (Eucoleus contortus, Baruscapillaria mergi, B. rudolphii, Amidostomum acutum, C. rudolphii, Tetrameres fissispina, Cosmocephalus obvelatus and Stegophorus stercorarii), three trematodes (Aporchis sp., Hyptiasmus sp. and Renicola sp.), one cestode (Diorchis nyrocae) and one acanthocephalan species (Andracantha phalacrocoracis). Of these, B. rudolphii from S. antiquus, C. rudolphii and Renicola sp. from A. cristatella, and C. obvelatus and Renicola sp. from B. perdix were first host records. Additionally, B. rudolphii was the first geographical record of this species in Japan

Solitary distant peritoneal metastasis of cecal cancer after laparoscopic colectomy : a case report

A 77-year-old Japanese female underwent laparoscopic ileocecal resection and lymph node dissection for cecal cancer by a previous doctor. Two years and 9 months after previous operation, contrast-enhanced computed tomography and magnetic resonance imaging with gadolinium ethoxybenzyl-L-diethylenetriamine pentaacetic acid revealed an intraperitoneal tumor at the right subphrenic fossa. 18F-fluorodeoxyglucose position emission tomography showed fluorodeoxyglucose accumulation in the tumor, and we suspected the tumor to be solitary distant peritoneal metastasis of the previous cecal cancer to the right diaphragm. We performed partial diaphragmectomy and direct closure, and pathological examination revealed moderately differentiated tubular adenocarcinoma resembling the previous cecal cancer, which seemed to be disseminated metastasis in the pathological features. Based on the intraoperative findings, we assumed the tumor to be solitary distant peritoneal metastasis caused by procedures during the previous laparoscopic operation. The present report suggests the importance of paying close attention to procedures during laparoscopic colorectal resection to prevent peritoneal seeding

Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae

We systematically surveyed period variations of superhumps in SU UMa-type dwarf novae based on newly obtained data and past publications. In many systems, the evolution of superhump period are found to be composed of three distinct stages: early evolutionary stage with a longer superhump period, middle stage with systematically varying periods, final stage with a shorter, stable superhump period. During the middle stage, many systems with superhump periods less than 0.08 d show positive period derivatives. Contrary to the earlier claim, we found no clear evidence for variation of period derivatives between superoutburst of the same object. We present an interpretation that the lengthening of the superhump period is a result of outward propagation of the eccentricity wave and is limited by the radius near the tidal truncation. We interpret that late stage superhumps are rejuvenized excitation of 3:1 resonance when the superhumps in the outer disk is effectively quenched. Many of WZ Sge-type dwarf novae showed long-enduring superhumps during the post-superoutburst stage having periods longer than those during the main superoutburst. The period derivatives in WZ Sge-type dwarf novae are found to be strongly correlated with the fractional superhump excess, or consequently, mass ratio. WZ Sge-type dwarf novae with a long-lasting rebrightening or with multiple rebrightenings tend to have smaller period derivatives and are excellent candidate for the systems around or after the period minimum of evolution of cataclysmic variables (abridged).Comment: 239 pages, 225 figures, PASJ accepte

Coincident Port-site and Functional End-to-end Anastomotic Recurrences after Laparoscopic Surgery for Colon Cancer : A case report and literature review

Herein, we report coincident recurrences at the port site and functional end-to-end anastomosis after laparoscopic right hemicolectomy for cancer of the ascending colon. The patient was an 83-year-old man who had undergone the aforementioned procedure (Stage IIA) in the referral hospital. At the 10-month follow-up, computed tomography showed two tumours around 3 cm in diameter : one on the right-flank abdominal wall-the surgical port-site-and the other at the functional end-to-end anastomosis. Likewise, a positron emission tomography scan was positive for two tumours. Endoscopic examination showed an ulcerated tumour with a clear margin, and a biopsy confirmed moderately differentiated tubular adenocarcinoma. The patient was diagnosed with coincident recurrences at the port site and functional end-to-end anastomosis after laparoscopic right hemicolectomy for cancer of the ascending colon. We re-operated inMarch 2016. The tumours at the functional end-to-end anastomosisand functional end-to-end anastomosiswere resected. After 7 months, no recurrence was detected

Pathological Endogenous α-Synuclein Accumulation in Oligodendrocyte Precursor Cells Potentially Induces Inclusions in Multiple System Atrophy.

Glial cytoplasmic inclusions (GCIs), commonly observed as α-synuclein (α-syn)-positive aggregates within oligodendrocytes, are the pathological hallmark of multiple system atrophy. The origin of α-syn in GCIs is uncertain; there is little evidence of endogenousα-syn expression in oligodendrocyte lineage cells, oligodendrocyte precursor cells (OPCs),and mature oligodendrocytes (OLGs). Here, based on in vitro analysis using primary rat cell cultures, we elucidated that preformed fibrils (PFFs) generated from recombinant human α-syn trigger multimerization and an upsurge of endogenous α-syn in OPCs, which is attributable to insufficient autophagic proteolysis. RNA-seq analysis of OPCs revealed that α-syn PFFs interfered with the expression of proteins associated with neuromodulation and myelination. Furthermore, we detected cytoplasmic α-syn inclusions in OLGs through differentiation of OPCs pre-incubated with PFFs. Overall, our findings suggest the possibility of endogenous α-syn accumulation in OPCs that contributes to GCI formation and perturbation of neuronal/glial support in multiple system atrophy brains