The number of full exceptional collections modulo spherical twists for extended Dynkin quivers

This paper calculates the number of full exceptional collections modulo an action of a free abelian group of rank one for an abelian category of coherent sheaves on an orbifold projective line with a positive orbifold Euler characteristic, which is equivalent to the one of finite dimensional modules over an extended Dynkin quiver of ADE type by taking their derived categories. This is done by a recursive formula naturally generalizing the one for the Dynkin case by Deligne whose categorical interpretation is due to Obaid--Nauman--Shammakh--Fakieh--Ringel. Moreover, the number coincides with the degree of the Lyashko--Looijenga map of the Frobenius manifold for the orbifold projective line, which hints a consistency in some problems in Bridgeland's stability conditions and mirror symmetry.Comment: 27 pages, 1 figure, 7 table

Human Beings in Antarctica

Research on Antarctica has been continuing for over a century. While living in Antarctica remains difficult owing to the extreme conditions there, expeditions have progressed greatly in improving accommodations. Expeditioners are exposed to a harsh natural environment such as coldness, dryness, dramatic change in sunshine time, ultraviolet rays, and high altitude. They also live in an extreme condition: closed small groups, absolute isolation, limited equipment and supplies, and no evacuation. As such, expedition members are placed in an extreme physical and mental state. Antarctic doctors are responsible for protecting the health of members who are wintering-over. Statistical analysis of diseases showed that the most common cases were of injuries followed by internal medicine and dental problems. Some diseases were related to environmental factors. Medical operations such as medical screening expedition, remote medical care, and telehealth care contribute to the safety, and better health management systems are themselves subjects of research. Medical researches and operations are advancing and supporting one another. As a simulation of space, the Antarctic experience and the related breakthrough are utilised in space research. Outcomes of research on Antarctica contribute to the better understanding of human society as well

Connective tissue mast cells store and release noradrenaline

Mast cells are present in mucosal and connective tissues throughout the body. They synthesize and release a wide variety of bioactive molecules, such as histamine, proteases, and cytokines. In this study, we found that a population of connective tissue mast cells (CTMCs) stores and releases noradrenaline, originating from sympathetic nerves. Noradrenaline-storing cells, not neuronal fibers, were predominantly identified in the connective tissues of the skin, mammary gland, gastrointestinal tract, bronchus, thymus, and pancreas in wild-type mice but were absent in mast cell-deficient W-sash c-kit mutant KitW-sh/W-sh mice. In vitro studies using bone marrow-derived mast cells revealed that extracellular noradrenaline was taken up but not synthesized. Upon ionomycin stimulation, noradrenaline was released. Electron microscopy analyses further suggested that noradrenaline is stored in and released from the secretory granules of mast cells. Finally, we found that noradrenaline-storing CTMCs express organic cation transporter 3 (Oct3), which is also known as an extraneuronal monoamine transporter, SLC22A3. Our findings indicate that mast cells may play a role in regulating noradrenaline concentration by storing and releasing it in somatic tissues

Evaluating Health Impact at High Altitude in Antarctica and Effectiveness of Monitoring Oxygen Saturation

[Background] The Japanese Antarctic Research Expedition (JARE) has been conducting research activities in inland Antarctica, which is extremely cold dryland covered with a thick ice sheet. This environment may cause a health disorder called acute mountain sickness (AMS). To improve the safety of expedition members, we evaluated the impact of extreme environmental conditions on human health and the effectiveness of monitoring of hypoxia for the early detection of AMS. [Methods] In total, 9 members from JARE 59 were studied. Dome Fuji Station (Dome F), located 3,810 m above sea level (ASL), was the destination of the research party. We analyzed daily AMS scores (higher values correspond to more severe AMS-related symptoms), physiological findings, and percutaneous arterial blood oxygen saturation (SpO2) during the inland activity. We also determined the factors related to AMS scores. [Results] The average AMS score on arrival at Dome F was significantly higher than that at the departure point (560 m ASL). The average SpO2 level was significantly lower than that at other points. The SpO2 level correlated negatively with the AMS score in Spearman’s rank correlation. Generalized estimating equations analysis showed that the AMS score was negatively associated with SpO2 level and positively associated with age. [Conclusion] Hypoxia is a contributory factor to AMS which we can easily assess by measuring the SpO2 level with a pulse oximeter. SpO2 monitoring is a potentially useful health management tool for members in inland Antarctic expeditions. In addition, our results are helpful for understanding physiological responses and health issues in extreme environments

Post-Cataract Surgery Visual Disturbance in a Retinitis Pigmentosa Patient with Asteroid Hyalosis

A patient with retinitis pigmentosa showed visual disturbances following successful cataract surgery. He had a dense asteroid hyalosis in the eye before cataract surgery. After the surgery he noticed that his vision became worse. The visual disturbance was explained as being caused by the progression of retinal degeneration. Although the electroretinogram was non-recordable, the degeneration of macular area appeared relatively small. We considered that dense asteroid hyalosis was responsible for his visual disturbances, and pars plana vitrectomy (PPV) was performed to remove the asteroid hyalosis. After the PPV, rapid improvement of his visual acuity was observed. Cataract surgery may affect the status of asteroid hyalosis and cause rapid visual loss. PPV should be considered for retinitis pigmentosa patients with dense asteroid hyalosis, especially when a large decrease in visual acuity is noted shortly after cataract surgery

Outer retinal circular structures in patients with Bietti crystalline retinopathy.

[Background] : Bietti crystalline retinopathy (BCR) is a distinct retinal degenerative disease characterised by retinal degeneration with many yellow–white crystals located mainly at the posterior pole area. Using spectral domain-optical coherence tomography (SD-OCT), the structural change in retina was investigated. [Methods] : Patients diagnosed with BCR (n=12), retinitis pigmentosa (RP, n=292) and cone dystrophy (n=16) were included in this study. The authors mainly examined fundus photographs and SD-OCT, infrared and fundus autofluorescence images of these patients. [Results]: Crystalline deposits were detected in portions of the retinal pigment epithelium that lacked patchy degenerated lesions. SD-OCT revealed that most of the observed crystalline deposits were located adjacent to the inner side of retinal pigment epithelium layer. The change most frequently observed was circular hyper-refractive structures in the outer nuclear layer. Although the structures were considered to be previously reported “tubular formation” or “tubular degeneration”, we determined that many of these circular structures were slices of spherical structures and were typically noted in areas suspected of ongoing active degeneration. [Conclusion] : BCR has characteristic structures in the outer nuclear layer. Although the incidence of the structure varies, it may be characteristic of retinal degeneration and can be found in many retinal degenerative diseases

Development of a 1,3a,6a-triazapentalene derivative as a compact and thiol-specific fluorescent labeling reagent

For the fluorescence imaging of biologically active small compounds, the development of compact fluorophores that do not perturb bioactivity is required. Here we report a compact derivative of fluorescent 1,3a,6a-triazapentalenes, 2-isobutenylcarbonyl-1,3a,6a-triazapentalene (TAP-VK1), as a fluorescent labeling reagent. The reaction of TAP-VK1 with various aliphatic thiols proceeds smoothly to afford the corresponding 1,4-adducts in high yields, and nucleophiles other than thiols do not react. After the addition of thiol groups in dichloromethane, the emission maximum of TAP-VK1 shifts to a shorter wavelength and the fluorescence intensity is substantially increased. The utility of TAP-VK1 as a compact fluorescent labeling reagent is clearly demonstrated by the labeling of Captopril, which is a small molecular drug for hypertension. The successful imaging of Captopril, one of the most compact drugs, in this study demonstrates the usefulness of compact fluorophores for mechanistic studies

Concentric division of 10° visual field tests in retinitis pigmentosa.

The purpose of this study was to estimate the optimal size of visual field test for detecting longitudinal changes in retinitis pigmentosa (RP) by dividing the visual field