A lack of classical Cepheids in the inner part of the Galactic disk

Recent large-scale infrared surveys have been revealing stellar populations in the inner Galaxy seen through strong interstellar extinction in the disk. In particular, classical Cepheids with their period-luminosity and period-age relations are useful tracers of Galactic structure and evolution. Interesting groups of Cepheids reported recently include four Cepheids in the Nuclear Stellar Disk (NSD), about 200 pc around the Galactic Centre, found by Matsunaga et al. and those spread across the inner part of the disk reported by Dekany and collaborators. We here report our discovery of nearly thirty classical Cepheids towards the bulge region, some of which are common with Dekany et al., and discuss the large impact of the reddening correction on distance estimates for these objects. Assuming that the four Cepheids in the NSD are located at the distance of the Galactic Centre and that the near-infrared extinction law, i.e. wavelength dependency of the interstellar extinction, is not systematically different between the NSD and other bulge lines-of-sight, most of the other Cepheids presented here are located significantly further than the Galactic Centre. This suggests a lack of Cepheids in the inner 2.5 kpc region of the Galactic disk except the NSD. Recent radio observations show a similar distribution of star-forming regions.Comment: 8 pages, 4 figures, accepted for publication in MNRA

Short germ insects utilize both the ancestral and derived mode of Polycomb group-mediated epigenetic silencing of Hox genes

In insect species that undergo long germ segmentation, such as Drosophila, all segments are specified simultaneously at the early blastoderm stage. As embryogenesis progresses, the expression boundaries of Hox genes are established by repression of gap genes, which is subsequently replaced by Polycomb group (PcG) silencing. At present, however, it is not known whether patterning occurs this way in a more ancestral (short germ) mode of embryogenesis, where segments are added gradually during posterior elongation. In this study, two members of the PcG family, Enhancer of zeste (E(z)) and Suppressor of zeste 12 (Su(z)12), were analyzed in the short germ cricket, Gryllus bimaculatus. Results suggest that although stepwise negative regulation by gap and PcG genes is present in anterior members of the Hox cluster, it does not account for regulation of two posterior Hox genes, abdominal-A (abd-A) and Abdominal-B (Abd-B). Instead, abd-A and Abd-B are predominantly regulated by PcG genes, which is the mode present in vertebrates. These findings suggest that an intriguing transition of the PcG-mediated silencing of Hox genes may have occurred during animal evolution. The ancestral bilaterian state may have resembled the current vertebrate mode of regulation, where PcG-mediated silencing of Hox genes occurs before their expression is initiated and is responsible for the establishment of individual expression domains. Then, during insect evolution, the repression by transcription factors may have been acquired in anterior Hox genes of short germ insects, while PcG silencing was maintained in posterior Hox genes

Involvement of dachshund and Distal-less in distal pattern formation of the cricket leg during regeneration

Cricket nymphs have the remarkable ability to regenerate a functional leg following amputation, indicating that the regenerating blastemal cells contain information for leg morphology. However, the molecular mechanisms that underlie regeneration of leg patterns remain poorly understood. Here, we analyzed phenotypes of the tibia and tarsus (three tarsomeres) obtained by knockdown with regeneration-dependent RNA interference (rdRNAi) against Gryllus dachshund (Gb'dac) and Distal-less (Gb'Dll). We found that depletion of Gb'Dll mRNA results in loss of the tarsal segments, while rdRNAi against Gb'dac shortens the tibia at the two most distal tarsomeres. These results indicate that Gb'Dll expression is indispensable for formation of the tarsus, while Gb'dac expression is necessary for elongation of the tibia and formation of the most proximal tarsomere. These findings demonstrate that mutual transcriptional regulation between the two is indispensable for formation of the tarsomeres, whereas Gb'dac is involved in determination of tibial size through interaction with Gb'ds/Gb'ft

Prevalence and clinical manifestations of gastro-oesophageal reflux-associated chronic cough in the Japanese population

Gastro-oesophageal reflux (GOR) is one of the most common causes of chronic cough in Western countries, responsible for 10 to 40% of cases. In Japan, however, GOR-associated chronic cough (GOR-CC) has been rarely reported and its clinical manifestation including frequency of concomitant reflux laryngitis is poorly known. We have analyzed prevalence and clinical characteristics of patients who were diagnosed as having GOR-CC among adult patients with chronic cough (≥ 8 weeks) who visited our asthma and cough clinic over a period of 19 months. Diagnosis of GOR-CC was based on the response of coughing to a proton-pump inhibitor (lansoprazole™) and/or positive results of 24 h ambulatory esophageal pH monitoring. Laryngeal involvement was based on symptoms or objective diagnosis by specialists. GOR-associated chronic cough was diagnosed in 7.1% (8 of 112) of chronic cough patients. In addition to the demographic data which were consistent with the characteristics of patients with GOR-CC in the Western populations, including gender (6 females), age (mean ± SE, 56.9 ± 5.8 years), duration of cough (9.9 ± 3.3 months), lack of gastrointestinal symptoms (3 of 8) and complication with other causes of cough (5 of 8), we found the standard range of body mass index (23.9 ± 1.5 kg/m(2)) and high incidence of concomitant reflux laryngitis (5 of 8) in the present 8 patients. Among 4 patients who could stop treatment with temporal resolution of cough, cough recurred in 3 patients, 1 week to 8 months after the discontinuation. In conclusion, GOR-CC is a less frequent cause of chronic cough in Japan than in Western countries. Signs or symptoms of laryngitis may be important as clues to suspicion of GOR-CC

Features of cough variant asthma and classic asthma during methacholine-induced brochoconstriction: a cross-sectional study

[Background]Little is known regarding mechanistic and phenotypic differences between cough variant asthma (CVA), presenting with a chronic cough as the sole symptom that responds to bronchodilators, and classic asthma with wheezing during methacholine inhalation. Here we reported airway sensitivity, airway reactivity, and as the main concern, the appearance of cough and wheezes during methacholine inhalation in patients with CVA or classic asthma. [Methods]We cross-sectionally examined the degrees of airway sensitivity, the point where resistance started to increase, and reactivity, the slope of the methacholine-resistance curve, and the appearance of cough and wheezes in steroid-naive adult patients with classic asthma (n = 58) or CVA (n = 55) while they were continuously inhaling methacholine during simultaneous measurement of respiratory resistance. [Results]Patients with CVA were less sensitive and less reactive to inhaled methacholine and wheezed less frequently but coughed more frequently during methacholine-induced bronchoconstriction than did patients with classic asthma. Multivariate analysis revealed that airway hypersensitivity and lower baseline FEV1/FVC were associated with the appearance of wheezes, whereas a diagnosis of CVA was associated with coughing. [Conclusion]There are mechanistic and phenotypic differences between CVA and classic asthma during methacholine inhalation. Frequent coughing during bronchoconstriction may be a distinctive feature of CVA

Regulation of JH biosynthesis by TGF-β signaling

While butterflies undergo a dramatic morphological transformation from larvae to adult via a pupal stage (e.g., holometamorphosis), crickets undergo a metamorphosis from nymph to adult without formation of a pupa (e.g., hemimetamorphosis). Despite these differences, both processes are regulated by common mechanisms that involve 20-hydroxyecdysone (20E) and juvenile hormone (JH). JH regulates many aspects of insect physiology, such as development, reproduction, diapauses, and metamorphosis. Consequently, strict regulation of JH levels is crucial throughout an insect’s life cycle. However, it remains unclear how JH synthesis is regulated. Here, we report that in the corpora allata (CA) of the cricket, Gryllus bimaculatus (Gb), Myoglianin (Gb’Myo), a homolog of Drosophila Myoglianin/vertebrate GDF8/11, is involved in the down-regulation of JH production by suppressing expression of a gene encoding JH acid O-methyltransferase, Gb’jhamt. In contrast, JH production is up-regulated by Decapentaplegic (Gb’Dpp) and Glass bottom boat/60A (Gb’Gbb) signaling that occurs as part of the transcriptional activation of Gb’jhamt. Gb’Myo defines the nature of each developmental transition by regulating JH titre and the interactions between JH and 20E. When Gb’myo expression is suppressed, activation of Gb’jhamt expression and secretion of 20E induces molting, thereby leading to the next instar prior to the last nymphal instar. Conversely, high Gb’myo expression induces metamorphosis during the last nymphal instar due to cessation of JH synthesis. Gb’myo also regulates final insect size. Since Myoglianin/GDF8/11 and Dpp/BMP2/4-Gbb/BMP5-8 are conserved in both invertebrates and vertebrates, the present findings provide common regulatory mechanisms regarding endocrine control of animal development

New readout and data-acquisition system in an electron-tracking Compton camera for MeV gamma-ray astronomy (SMILE-II)

For MeV gamma-ray astronomy, we have developed an electron-tracking Compton camera (ETCC) as a MeV gamma-ray telescope capable of rejecting the radiation background and attaining the high sensitivity of near 1 mCrab in space. Our ETCC comprises a gaseous time-projection chamber (TPC) with a micro pattern gas detector for tracking recoil electrons and a position-sensitive scintillation camera for detecting scattered gamma rays. After the success of a first balloon experiment in 2006 with a small ETCC (using a 10$\times$10$\times$15 cm$^3$ TPC) for measuring diffuse cosmic and atmospheric sub-MeV gamma rays (Sub-MeV gamma-ray Imaging Loaded-on-balloon Experiment I; SMILE-I), a (30 cm)$^{3}$ medium-sized ETCC was developed to measure MeV gamma-ray spectra from celestial sources, such as the Crab Nebula, with single-day balloon flights (SMILE-II). To achieve this goal, a 100-times-larger detection area compared with that of SMILE-I is required without changing the weight or power consumption of the detector system. In addition, the event rate is also expected to dramatically increase during observation. Here, we describe both the concept and the performance of the new data-acquisition system with this (30 cm)$^{3}$ ETCC to manage 100 times more data while satisfying the severe restrictions regarding the weight and power consumption imposed by a balloon-borne observation. In particular, to improve the detection efficiency of the fine tracks in the TPC from $\sim$10\% to $\sim$100\%, we introduce a new data-handling algorithm in the TPC. Therefore, for efficient management of such large amounts of data, we developed a data-acquisition system with parallel data flow.Comment: 11 pages, 24 figure