74 research outputs found
The brightest UV-selected galaxies in protoclusters at : Ancestors of Brightest Cluster Galaxies?
We present the results of a survey of the brightest UV-selected galaxies in
protoclusters. These proto-brightest cluster galaxy (proto-BCG) candidates are
drawn from 179 overdense regions of -dropout galaxies at from the
Hyper Suprime-Cam Subaru Strategic Program identified previously as good
protocluster candidates. This study is the first to extend the systematic study
of the progenitors of BCGs from to . We carefully remove
possible contaminants from foreground galaxies and, for each structure, we
select the brightest galaxy that is at least 1 mag brighter than the fifth
brightest galaxy. We select 63 proto-BCG candidates and compare their
properties with those of galaxies in the field and those of other galaxies in
overdense structures. The proto-BCG candidates and their surrounding galaxies
have different rest-UV color distributions to field galaxies and
other galaxies in protoclusters that do not host proto-BCGs. In addition,
galaxies surrounding proto-BCGs are brighter than those in protoclusters
without proto-BCGs. The image stacking analysis reveals that the average
effective radius of proto-BCGs is larger than that of field
galaxies. The color differences suggest that proto-BCGs and their
surrounding galaxies are dustier than other galaxies at . These results
suggest that specific environmental effects or assembly biasses have already
emerged in some protoclusters as early as , and we suggest that
proto-BCGs have different star formation histories than other galaxies in the
same epoch.Comment: 18 pages, 11 figures, Accepted for publication in Ap
A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). VI. Distant Filamentary Structures Pointed Out by High- z Radio Galaxies at z ∼4
We present the environmental properties around high- radio galaxies
(HzRGs) at , which have been poorly investigated because of their
rarity. We use the largest samples of HzRGs and -dropout galaxy overdense
regions at , which were constructed from Hyper Suprime-Cam Subaru
Strategic Program, to characterize the HzRG environments statistically. We
measure the -dropout galaxy overdensities around 21 HzRGs whose rest-frame
1.4 GHz radio luminosities () are W
Hz. We find that the overdensities around the faint HzRGs with
W Hz tend to be higher than that
of the -dropout galaxies. On the other hand, no significant difference of
density environments is found between the luminous HzRGs with W Hz and the -dropout
galaxies. The HzRGs are found to occupy more massive halos than -dropout
galaxies through a cross-correlation between the HzRGs and -dropout
galaxies. This trend is more pronounced in the faint HzRGs. These results are
consistent with a scenario where HzRGs get older and more massive as the
radio-luminosity decreases. The HzRGs are expected to trace the progenitors of
local cluster halos from their calculated halo mass. In addition, we find that
surrounding galaxies tend to distribute along the radio-jet major axis of the
HzRGs at angular distances less than physical kpc. Our findings
imply the onset of the filamentary structures around the HzRGs at .Comment: 22 pages, 8 figures, accepted in Ap
A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). IX. The most overdense region at z ∼ 5 inhabited by a massive radio galaxy
We report on the galaxy density environment around a high-z radio galaxy (HzRG) at z = 4.72, HSC J083913.17+011308.1 (HSC J0839+0113), probed using an r-dropout Lyman break galaxy (LBG) sample from the Hyper Suprime-Cam Subaru Strategic Program data. We find that HSC J0839+0113 resides in the outskirts of an overdense region identified by the r-dropout galaxies at a 4.7σ significance level. The projected distance between HSC J0839+0113 and the peak position of the overdense region is 0.4 physical Mpc, which is shorter than the typical protocluster radius in this epoch. According to the extended Press–Schechter and the light cone models, the HSC J0839+0113-hosted overdense region is expected to evolve into a halo >1014 M⊙ at z = 0 with a high probability of >80%. These findings suggest that HSC J0839+0113 is associated with a protocluster. The HSC J0839+0113 rich-system is the most overdense region of LBGs among the known protoclusters with LBGs in the same cosmic epoch
The Association of Postprandial Triglyceride Variability with Renal Dysfunction and Microalbuminuria in Patients with Type 2 Diabetic Mellitus: A Retrospective and Observational Study
Objective. We examined whether or not day-to-day variations in lipid profiles, especially triglyceride (TG) variability, were associated with the exacerbation of diabetic kidney disease. Methods. We conducted a retrospective and observational study. First, 527 patients with type 2 diabetes mellitus (DM) who had had their estimated glomerular filtration rate (eGFR) checked every 6 months since 2012 for over 5 years were registered. Variability in postprandial TG was determined using the standard deviation (SD), SD adjusted (Adj-SD) for the number of measurements, and maximum minus minimum difference (MMD) during the first three years of follow-up. The endpoint was a & GE;40% decline from baseline in the eGFR, initiation of dialysis or death. Next, 181 patients who had no micro- or macroalbuminuria in February 2013 were selected from among the 527 patients for an analysis. The endpoint was the incidence of microalbuminuria, initiation of dialysis, or death. Results. Among the 527 participants, 110 reached a & GE;40% decline from baseline in the eGFR or death. The renal survival was lower in the higher-SD, higher-Adj-SD, and higher-MMD groups than in the lower-SD, lower-Adj-SD, and lower-MMD groups, respectively (log-rank test p=0.0073, 0.0059, and 0.0195, respectively). A lower SD, lower Adj-SD, and lower MMD were significantly associated with the renal survival in the adjusted model (hazard ratio, 1.62, 1.66, 1.59; 95% confidence intervals, 1.05-2.53, 1.08-2.58, 1.04-2.47, respectively). Next, among 181 participants, 108 developed microalbuminuria or death. The nonincidence of microalbuminuria was lower in the higher-SD, higher-Adj-SD, and higher-MMD groups than in the lower-SD, lower-Adj-SD, and lower-MMD groups, respectively (log-rank test p=0.0241, 0.0352, and 0.0474, respectively). Conclusions. Postprandial TG variability is a novel risk factor for eGFR decline and the incidence of microalbuminuria in patients with type 2 DM
Faint Quasars Live in the Same Number Density Environments as Lyman Break Galaxies at z∼4
Characterizing high-z quasar environments is key to understanding the
co-evolution of quasars and the surrounding galaxies. To restrict their global
picture, we statistically examine the g-dropout galaxy overdensity distribution
around 570 faint quasar candidates at z ~ 4, based on the Hyper Suprime-Cam
Subaru Strategic Program survey. We compare the overdensity significances of
g-dropout galaxies around the quasars with those around g-dropout galaxies, and
find no significant difference between their distributions. A total of 4 (22)
out of the 570 faint quasars, 0.7_{-0.4}^{+0.4} (3.9_{-0.8}^{+0.8}) %, are
found to be associated with the > 4 sigma overdense regions within an angular
separation of 1.8 (3.0) arcmin, which is the typical size of protoclusters at
this epoch. This is similar to the fraction of g-dropout galaxies associated
with the > 4 sigma overdense regions. This result is consistent with our
previous work that 1.3_{-0.9}^{+0.9} % and 2.0_{-1.1}^{+1.1} % of luminous
quasars detected in the Sloan Digital Sky Survey exist in the > 4 sigma
overdense regions within 1.8 and 3.0 arcmin separations, respectively.
Therefore, we suggest that the galaxy number densities around quasars are
independent of their luminosity, and most quasars do not preferentially appear
in the richest protocluster regions at z ~ 4. The lack of an apparent positive
correlation between the quasars and the protoclusters implies that: i) the
gas-rich major merger rate is relatively low in the protocluster regions, ii)
most high-z quasars may appear through secular processes, or iii) some
dust-obscured quasars exist in the protocluster regions.Comment: 12 pages, 4 figure
Clinical background factors as predictors of the efficacy of 5-aminosalicylic acid suppositories in patients with ulcerative colitis
Introduction: Although the efficacy of 5-aminosalicylic acid (ASA) suppositories for ulcerative colitis (UC) has been reported in many studies, many studies have also described poor adherence to 5-ASA suppository regimens. We aimed to identify the clinical background factors that influence adherence to 5-ASA suppositories to improve adherence and efficacy of the treatment.
Methods: We conducted a retrospective cohort study of 61 patients with active UC who were using 5-ASA suppositories. All patients underwent endoscopy and rectal biopsy for histological diagnosis prior to 5-ASA suppository treatment. The efficacy of 5-ASA suppository treatment was compared in relation to clinical background factors (sex, age, disease duration, disease type, clinical activity, Ulceratve colitis Endoscopic Index of Severity, histological activity, serum C-reactive protein level, concomitant use of immunomodulators, history of steroid use, and dose of oral 5-ASA).
Results: The efficacy of 5-ASA suppositories was significantly related to low Lichtiger Colitis Activity Index (LCAI) scores and proctitis type prior to its use. In terms of sex, females tended to show higher efficacy. Multivariate logistic regression analysis using these three factors showed high predictive value for the efficacy of 5-ASA suppositories (AUC, 0.788; sensitivity, 87.2%; and specificity, 63.7%).
Discussion/Conclusion: This study is the first to extract clinical background factors for predicting the efficacy of 5-ASA suppositories. The use of 5-ASA suppositories in patients who are expected to show efficacy will be effective in improving patient co-operation
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