Computing NP-Hard Repetitiveness Measures via MAX-SAT

Repetitiveness measures reveal profound characteristics of datasets, and give rise to compressed data structures and algorithms working in compressed space. Alas, the computation of some of these measures is NP-hard, and straight-forward computation is infeasible for datasets of even small sizes. Three such measures are the smallest size of a string attractor, the smallest size of a bidirectional macro scheme, and the smallest size of a straight-line program. While a vast variety of implementations for heuristically computing approximations exist, exact computation of these measures has received little to no attention. In this paper, we present MAX-SAT formulations that provide the first non-trivial implementations for exact computation of smallest string attractors, smallest bidirectional macro schemes, and smallest straight-line programs. Computational experiments show that our implementations work for texts of length up to a few hundred for straight-line programs and bidirectional macro schemes, and texts even over a million for string attractors

Spontaneous esophageal perforation within a hiatal hernia : A case report

Introduction: Spontaneous esophageal perforation, also commonly referred to as Boerhaave's syndrome, is one of the most lethal diseases causing an acute abdomen. Though rare, emergent surgical intervention is often required and management can be various based upon the site of the perforation. This literature has been written in line with the SCARE criteria (Agha et al., 2020) [1]. Presentation of case: A 76-year-old man presented with acute abdominal pain. Computed tomography (CT) revealed and an emergent esophagogastroduodenoscopy (EGD) was performed carefully, which revealed a 7 cm all-layer esophageal laceration in the left lower esophageal wall. In our case, a hiatal hernia was protruding into the mediastinum, and the perforation site was inside of it, but there was no invasion into the thoracic cavity, thus a transabdominal approach was performed without thoracotomy. Discussion: This type of esophageal perforation within a hiatal hernia is quite rare and provides a unique clinical challenge. In addition, A review reported the average length of spontaneous esophageal perforation to be around 2 cm while our case had a perforation with a length of 7 cm. We chose the combination of the simple suture with omental buttress and wide drainage, but a complete fundoplication was impossible due to its large size of perforation. Conclusion: We chose the open abdominal approach because the case had high inflammation, a hiatal hernia and possibility of retro-gastric perforation. However, MIS should have been considered first if a situation or human resources allow it

Development of a Vertex Finding Algorithm using Recurrent Neural Network

Deep learning is a rapidly-evolving technology with possibility to significantly improve physics reach of collider experiments. In this study we developed a novel algorithm of vertex finding for future lepton colliders such as the International Linear Collider. We deploy two networks; one is simple fully-connected layers to look for vertex seeds from track pairs, and the other is a customized Recurrent Neural Network with an attention mechanism and an encoder-decoder structure to associate tracks to the vertex seeds. The performance of the vertex finder is compared with the standard ILC reconstruction algorithm.Comment: 8 pages, 8 figures, preliminary version currently under review by IL

Reactions of 1-hydroxyindoles with p-toluenesulfonyl chloride and p-toluenesulfonic acid

金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学

The optical spectrum of a large isolated polycyclic aromatic hydrocarbon: hexa-peri-hexabenzocoronene, C42H18

The first optical spectrum of an isolated polycyclic aromatic hydrocarbon large enough to survive the photophysical conditions of the interstellar medium is reported. Vibronic bands of the first electronic transition of the all benzenoid polycyclic aromatic hydrocarbon hexa-peri-hexabenzocoronene were observed in the 4080-4530 Angstrom range by resonant 2-color 2-photon ionization spectroscopy. The strongest feature at 4264 Angstrom is estimated to have an oscillator strength of f=1.4x10^-3, placing an upper limit on the interstellar abundance of this polycyclic aromatic hydrocarbon at 4x10^12 cm^-2, accounting for a maximum of ~0.02% of interstellar carbon. This study opens up the possibility to rigorously test neutral polycyclic aromatic hydrocarbons as carriers of the diffuse interstellar bands in the near future.Comment: 9 pages, 1 figure. Fixed a typo on the frequency of the 'b' ban

Schwannoma resembling metastatic lymph node

In this report, we describe a rare case of vagus nerve schwannoma associated with esophageal cancer. A 70-year-old man visited our hospital complaining of worsening dysphagia. His upper gastrointenstinal endoscopy revealed a mass in the esophagus. A contrast-enhanced chest computed tomography also detected a 15 mm nodule attached to the tracheal membrane. This nodule was diagnosed as a metastatic lymph node. Although the primary tumor reduced after neoadjuvant chemotherapy, the nodule remained intact ; it showed fluorodeoxyglucose accumulation on positron emission tomography. We had a clinical diagnosis of stage III after neoadjuvant chemotherapy and underwent surgery. Intraoperatively, the nodule could not be detached from the right vagus nerve ; therefore, we excised the nodule along with the adjacent vagus nerve. The nodule was pathologically diagnosed as a vagus schwannoma. The nodule was not a regional lymph node metastasis of esophageal cancer. His postoperative course was uneventful, and he is currently undergoing outpatient follow-up without recurrence