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

Solving McEliece-1409 in One Day --- Cryptanalysis with the Improved BJMM Algorithm

Syndrome decoding problem (SDP) is the security assumption of the code-based cryptography. Three out of the four NIST-PQC round 4 candidates are code-based cryptography. Information set decoding (ISD) is known for the fastest existing algorithm to solve SDP instances with relatively high code rate. Security of code-based cryptography is often constructed on the asymptotic complexity of the ISD algorithm. However, the concrete complexity of the ISD algorithm has hardly ever been known. Recently, Esser, May and Zweydinger (Eurocrypt \u2722) provide the first implementation of the representation-based ISD, such as May--Meurer--Thomae (MMT) or Becker--Joux--May--Meurer (BJMM) algorithm and solve the McEliece-1284 instance in the decoding challenge, revealing the practical efficiency of these ISDs. In this work, we propose a practically fast depth-2 BJMM algorithm and provide the first publicly available GPU implementation. We solve the McEliece-1409 instance for the first time and present concrete analysis for the record. Cryptanalysis for NIST-PQC round 4 code-based candidates against the improved BJMM algorithm is also conducted. In addition, we revise the asymptotic space complexity of the time-memory trade-off MMT algorithm presented by Esser and Zweydinger (Eurocrypt \u2723) from $2^{0.375n}$ to $2^{0.376n}$

Encrusted Ureteral Stent Retrieval Using Flexible Ureteroscopy with a Ho: YAG Laser

A 23-year-old female had bilateral ureteral stents placed due to bilateral renal stones and hydronephrosis. The bilateral ureteral stents were changed every 3 months. A kidney ureter bladder (KUB) film showed left encrustation along the ureteral stent thus necessitating removal; however, the ureteral stent could not be removed cystoscopically. The ureteral stent was, therefore, extracted using flexible ureteroscopy (URS) with a holmium (Ho): yttrium aluminum garnet (YAG) laser

Effects of Different Types of Dietary Fibers on Fermentation by Intestinal Flora

Purpose: A treatment for chronic constipation is dietary fiber intake. This study aimed to determine the effects of different types of dietary fibers on the microbiota in the large intestine. Methods: Nine healthy volunteers participated in this study. Breath hydrogen test was used to determine the dietary fiber fermentations. The presence of hydrogen in the breath indicates intestinal bacterial activities. Participants fasted overnight and ate white bread (200 g) with 10 g of each type of dietary fiber: (1) cellulose, (2) soy fiber, (3) guar gum, and (4) control (without any dietary fiber). Samples were collected before and every 1 hour after eating, for 8 h. Another test compared the effects between cellulose and guar gum with a loaded food, which activates intestinal fermentation, and samples were collected using the same methods. Results: During 8 h of measurements, breath hydrogen concentration in the soy fiber group were higher than that of the control, but were not significantly different. Changes in the guar gum group were similar to those in the control. However, breath hydrogen concentrations in the cellulose group did not increase even after eating white bread that caused large intestinal fermentation 2.9 ± 0.7 ppm, which was significantly lower than that of the guar gum group (7.4 ± 1.7 ppm, p < 0.01). In the study with a well-fermented food intake, cellulose reduced breath hydrogen concentrations, but its difference with that of the guar gum group was statistically non-significant. Conclusion: Cellulose might have a suppressive effect on large intestinal fermentation. Therefore, this compound may be beneficial in treating chronic constipation

Conserved fungal effector suppresses PAMP-triggered immunity by targeting plant immune kinases

Plant pathogens have optimized their own effector sets to adapt to their hosts. However, certain effectors, regarded as core effectors, are conserved among various pathogens, and may therefore play an important and common role in pathogen virulence. We report here that the widely distributed fungal effector NIS1 targets host immune components that transmit signaling from pattern recognition receptors (PRRs) in plants. NIS1 from two Colletotrichum spp. suppressed the hypersensitive response and oxidative burst, both of which are induced by pathogen-derived molecules, in Nicotiana benthamiana. Magnaporthe oryzae NIS1 also suppressed the two defense responses, although this pathogen likely acquired the NIS1 gene via horizontal transfer from Basidiomycota. Interestingly, the root endophyte Colletotrichum tofieldiae also possesses a NIS1 homolog that can suppress the oxidative burst in N. benthamiana. We show that NIS1 of multiple pathogens commonly interacts with the PRR-associated kinases BAK1 and BIK1, thereby inhibiting their kinase activities and the BIK1-NADPH oxidase interaction. Furthermore, mutations in the NIS1-targeting proteins, i.e., BAK1 and BIK1, in Arabidopsis thaliana also resulted in reduced immunity to Colletotrichum fungi. Finally, M. oryzae lacking NIS1 displayed significantly reduced virulence on rice and barley, its hosts. Our study therefore reveals that a broad range of filamentous fungi maintain and utilize the core effector NIS1 to establish infection in their host plants and perhaps also beneficial interactions, by targeting conserved and central PRR-associated kinases that are also known to be targeted by bacterial effectors

The association of ectopic craniopharyngioma in the fourth ventricle with familial adenomatous polyposis: illustrative case

[BACKGROUND] Craniopharyngioma (CP) often arises in the sellar and suprasellar areas; ectopic CP in the posterior fossa is rare. Familial adenomatous polyposis (FAP) is a genetic disorder involving the formation of numerous adenomatous polyps in the gastrointestinal tract, and it is associated with other extraintestinal manifestations. [OBSERVATIONS] The authors reported the case of a 63-year-old woman with FAP who presented with headache and harbored a growing mass in the fourth ventricle. Magnetic resonance imaging (MRI) findings revealed a well-circumscribed mass with high intensity on T1-weighted images and low intensity on T2-weighted images and exhibited no contrast enhancement. Gross total resection was performed and histopathology revealed an adamantinomatous CP (aCP). The authors also reviewed the previous reports of ectopic CP in the posterior fossa and found a high percentage of FAP cases among the ectopic CP group, thus suggesting a possible association between the two diseases. [LESSONS] An ectopic CP may be reasonably included in the differential diagnosis in patients with FAP who present with well-circumscribed tumors in the posterior fossa

Gallbladder Metastasis from Renal Cell Carcinoma

A 73-year-old female was operated with radical nephrectomy and cholecystectomy for renal cell carcinoma and suspected gallstones after 9 courses of sunitinib treatment. Gallbladder specimen showed gallbladder metastasis originating from the renal cell carcinoma. Gallbladder metastasis from renal cell carcinoma is rare. Here, we discuss a case of gallbladder metastasis from renal cell carcinoma

Neuroendocrine Carcinoma of the Bladder

The case was a 67-year-old male who visited our hospital with a major complaint of macroscopic hematuria. A bladder tumor was found. When a transurethral resection of the bladder tumor was performed, the histopathological diagnosis was neuroendocrine bladder cancer. After chemotherapy with cisplatin and etoposide a partial shrinkage of the tumor was observed; however, the patient expired 7 months after the first visit