33 research outputs found
Impact of astrophysical effects on the dark matter mass constraint with 21cm intensity mapping
We present an innovative approach to constraining the non-cold dark matter
model using a convolutional neural network (CNN). We perform a suite of
hydrodynamic simulations with varying dark matter particle masses and generate
mock 21cm radio intensity maps to trace the dark matter distribution. Our
proposed method complements the traditional power spectrum analysis. We compare
our CNN classification results with those from the power spectrum of the
differential brightness temperature map of 21cm radiation, and find that the
CNN outperforms the latter. Moreover, we investigate the impact of baryonic
physics on the dark matter model constraint, including star formation,
self-shielding of HI gas, and UV background model. We find that these effects
may introduce some contamination in the dark matter constraint, but they are
insignificant when compared to the realistic system noise of the SKA
instruments.Comment: 17 pages, 12 figure
JWST reveals a possible galaxy merger in triply-lensed MACS0647JD
MACS0647JD is a triply-lensed galaxy originally discovered with
the Hubble Space Telescope. Here we report new JWST imaging, which clearly
resolves MACS0647JD as having two components that are either merging
galaxies or stellar complexes within a single galaxy. Both are very small, with
stellar masses and radii . The brighter
larger component "A" is intrinsically very blue (), likely due
to very recent star formation and no dust, and is spatially extended with an
effective radius . The smaller component "B" appears redder
(), likely because it is older () with mild dust
extinction (), and a smaller radius . We
identify galaxies with similar colors in a high-redshift simulation, finding
their star formation histories to be out of phase. With an estimated stellar
mass ratio of roughly 2:1 and physical projected separation ,
we may be witnessing a galaxy merger 400 million years after the Big Bang. We
also identify a candidate companion galaxy C away, likely
destined to merge with galaxies A and B. The combined light from galaxies A+B
is magnified by factors of 8, 5, and 2 in three lensed images JD1, 2, and
3 with F356W fluxes , , (AB mag 25.1, 25.6, 26.6).
MACS0647JD is significantly brighter than other galaxies recently discovered
at similar redshifts with JWST. Without magnification, it would have AB mag
27.3 (). With a high confidence level, we obtain a photometric
redshift of based on photometry measured in 6 NIRCam filters
spanning , out to rest-frame. JWST NIRSpec
observations planned for January 2023 will deliver a spectroscopic redshift and
a more detailed study of the physical properties of MACS0647JD.Comment: 27 pages, 14 figures, submitted to Natur
Development of serum-free and grain-derived-nutrient-free medium using microalga-derived nutrients and mammalian cell-secreted growth factors for sustainable cultured meat production
Abstract Considering the amount of global resources and energy consumed, and animal welfare issues associated with traditional meat production, cultured meat production has been proposed as a solution to these problems and is attracting worldwide attention. Cultured meat is produced by culturing/proliferating animal muscle cells in vitro. This process requires significant amounts of culture medium, which accounts to a major portion of the production cost. Furthermore, it is composed of nutrients derived from grains and heterotrophic microorganisms and fetal bovine serum (FBS), which will impact the sustainability of cultured meat in future. Here, we developed a novel medium containing nutrients extracted from microalga and cell-secreted growth factors. First, rat liver epithelial RL34 cells were cultured by adding Chlorella vulgaris extract (CVE) to inorganic salt solution. The supernatant, containing the RL34 cell-secreted growth factors, was used as the conditioned medium (CM). This CM, with CVE added as a nutrient source, was applied to primary bovine myoblast cultures. This serum-free and grain-derived-nutrient-free medium promoted the proliferation of bovine myoblasts, the main cell source for cultured beef. Our findings will allow us to take a major step toward reducing production costs and environmental impacts, leading to an expansion of the cultured meat market
Lyman continuum leakage versus quenching with the James Webb Space Telescope : the spectral signatures of quenched star formation activity in reionization-epoch galaxies
In this paper, we study the effects of a recent drop in star formation rate (SFR) on the spectra of epoch of reionization (EoR) galaxies, and the resulting degeneracy with the spectral features produced by extreme Lyman continuum leakage. In order to study these effects in the wavelength range relevant for the upcoming James Webb Space Telescope (JWST), we utilize synthetic spectra of simulated EoR galaxies from cosmological simulations together with synthetic spectra of partially quenched mock galaxies. We find that rapid declines in the SFR of EoR galaxies could seriously affect the applicability of methods that utilize the equivalent width of Balmer lines and the ultraviolet spectral slope to assess the escape fraction of EoR galaxies. In order to determine if the aforementioned degeneracy can be avoided by using the overall shape of the spectrum, we generate mock NIRCam observations and utilize a classification algorithm to identify galaxies that have undergone quenching. We find that while there are problematic cases, JWST/NIRCam or NIRSpec should be able to reliably identify galaxies with redshifts z similar to 7 that have experienced a significant decrease in the SFR (by a factor of 10-100) in the past 50-100 Myr with a success rate greater than or similar to 85 per cent. We also find that uncertainties in the dust-reddening effects on EoR galaxies significantly affect the performance of the results of the classification algorithm. We argue that studies that aim to characterize the dust extinction law most representative in the EoR would be extremely useful.Correction in: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Volume: 496, Issue: 2, Pages: 1766-1767, DOI: 10.1093/mnras/staa1557</p
Experiment on endoscopic balloon dilation for esophageal stenosis after endoscopic submucosal dissection in pigs
Background and aim Endoscopic balloon dilation (EBD) is effective for esophageal stenosis caused by ESD. However, an efficient EBD method has not been established. We, therefore, conducted EBD experiments on porcine esophageal stenosis models. Methods Study 1: in dilation models (day 22 after ESD), the thickness of the outer muscle layer (as an index of the extension effect) and the area of muscle fiber bundle necrosis in the inner muscle layer (as an index of thermal damage) were evaluated. Study 2: in restenosis models (day 43 after ESD), the thickness of the fibrous plexus (as an index of restenosis) was evaluated. In total, 12 porcine models were created. Results Study 1: the thickness of the outer muscle layer was 1243 +/- 322 mu m in surrounding locations and it was 803 +/- 145 mu m beneath the laceration (p = 0.005). In cases of muscular layer injury, the area of necrosis was 15,500 +/- 10400 mu m(2) in surrounding locations and it was 40,200 +/- 12900 mu m(2) at the laceration site (p < 0.001). Study 2: the thickness of the fibrous plexus was 1359 +/- 196 mu m in surrounding locations and it was 1322 +/- 136 mu m(2) in the laceration scar site (p = 0.74). Conclusion Since thermal damage persists until the completion of stenosis, EBD in the initial stage should be carefully performed. An extension effect was observed only at the laceration site and it later returned to a status similar to that of surrounding locations. Additional intervention would be required for preventing restenosis
Health Literacy Is Associated with Activities of Daily Living of Patients Participating in Cardiac Rehabilitation: A Multicenter Clinical Study
The activities of daily living (ADL) in patients with cardiac disease tend to decline. A previous study revealed that ADL relates to physical and cognitive functions associated with health literacy (HL). However, the relationship between HL and ADL is not well documented. This study aimed to clarify this relationship among patients participating in cardiac rehabilitation. This multicenter study, the Kobe-Cardiac Rehabilitation project for people around the World (K-CREW), included patients who participated in cardiac rehabilitation from October 2020 to December 2021. Patients with probable dementia and difficulty walking alone were excluded. We used the 14-item Health Literacy Scale (HLS-14) to assess HL and the Functional Independence Measure (FIM) to assess ADL at discharge. Patients were divided by their HLS-14 score into the low HL group (<50 points) or the high HL group (≥50 points). We analyzed the relationship between the HLS-14 and FIM scores. We investigated 268 cardiac rehabilitation patients (median age, 71.0 years; male ratio, 76.9%). Low HL patients accounted for 51.1% of all patients and had significantly lower motor and cognitive FIM scores. Functional HL related better to the FIM scores (r = 0.28–0.36) than did other HL subclasses. Multiple regression analysis identified HLS-14 as an explanatory variable (p = 0.002) for the total FIM score. Patients with low HL had significantly lower ADL than those with high HL. These findings underscore the importance of considering HL in cardiac rehabilitation
Relationships of early esophageal cancer with human papillomavirus and alcohol metabolism
BACKGROUND It is well known that an alcohol consumption habit together with inactive heterozygous aldehyde dehydrogenase-2 (ALDH2) is an important risk factor for the development of esophageal squamous cell carcinoma (ESCC). It remains controversial whether human papillomavirus (HPV) infection contributes to the occurrence/development of ESCC. There has been no study in which the relationship between ESCC and HPV in addition to alcohol dehydrogenase-1B (ADH1B) and ALDH2 genotypes was evaluated. AIM To evaluate relationships between HPV infection and development of esophageal cancer, particularly early esophageal cancer, based on ADH1B/ALDH2 polymorphisms. METHODS We conducted an exploratory retrospective study using new specimens, and we enrolled 145 patients who underwent endoscopic resection for superficial ESCC and had been observed for more than two years by both physical examination and endoscopic examination in Hokkaido University Hospital. Saliva was collected to analyze genetic polymorphisms of ADH1B/ALDH2. We performed in situ hybridization for resected specimens to detect HPV by using an HPV type 16/18 probe. RESULTS HPV was detected in 15 (10.3%) of the 145 patients with ESCC. HPV-positive rates in inactive ALDH2*1/*2 and ALDH2*1/*1 + *2/*2 were 10.8% and 9.8%, respectively (P = 1.00). HPV-positive rates in slow-metabolizing ADH1B*1/*1 and ADH1B*1/*2 + *2/*2 were 12.0% and 10.0%, respectively (P = 0.72). HPV-positive rates in the heavy or moderate alcohol consumption group and the light or rare consumption group were 11.1% and 8.7%, respectively (P = 0.68). HPV-positive rates in the heavy smoking group and the light or no smoking group were 11.8% and 8.3%, respectively (P = 0.59). The 3-year incidence rates of secondary ESCC or head and neck cancer after initial treatment in the HPV-positive and HPV-negative groups were 14.4% and 21.4% (P = 0.22), respectively. CONCLUSION In the present situation, HPV status is considered to be less important than other risk factors, such as alcohol consumption, smoking habit, ADH1B/ALDH2 polymorphisms, and HPV status would therefore have no effect on ESCC risk management
Eradication of Helicobacter pylori may improve dyspepsia in the elderly for the long term
Background Therapy for eradication of Helicobacter pylori (H. pylori) improves symptoms of H. pylori-associated dyspepsia (HPD), but the effects of eradication in elderly patients are unclear. The aim of our study was to investigate dyspepsia symptoms and long-term effects of eradication in elderly patients. Methods This retrospective study included 496 patients who received H. pylori eradication therapy. The patients were divided into a group of elderly patients (group E: >= 65 years old) and a group of non-elderly patients (group N: < 65 years old). Abdominal symptoms were evaluated using a questionnaire about abdominal symptoms before eradication and after eradication (1-2 months and more than one year). Dyspepsia was defined as a score of 4 points or more for at least one of 4 items (postprandial fullness, early satiety, epigastric pain, and hunger pain). Improvement of symptoms was defined on the basis of changes in Global Overall Systems scores. Results There were no differences in abdominal symptoms before eradication between the two groups. Successful eradication improved symptoms in patients with dyspepsia within 2 months (in 75.6% (56/74) of the patients in group N and in 64.5% (20/31) of the patients in group E). The questionnaire showed that 80% (32/40) of the patients in group N and 60% (12/20) of the patients in group E had long-term relief of dyspepsia. The scores for abdominal symptoms in group E continued to improve for a mean period of 54.8 months after eradication. Conclusions Eradication of H. pylori age-independently improved dyspepsia symptoms for the long term