The Subaru Deep Field Project: Lymanα\alpha Emitters at Redshift of 6.6

We present new results of a deep optical imaging survey using a narrowband filter ($NB921$) centered at $\lambda =$ 9196 \AA ~ together with $B$, $V$, $R$, $i^\prime$, and $z^\prime$ broadband filters in the sky area of the Subaru Deep Field which has been promoted as one of legacy programs of the 8.2m Subaru Telescope. We obtained a photometric sample of 58 Ly$\alpha$ emitter candidates at $z \approx$ 6.5 -- 6.6 among $\sim 180$ strong $NB921$-excess ($z^\prime - NB921 > 1.0$) objects together with a color criterion of $i^\prime - z^\prime > 1.3$. We then obtained optical spectra of 20 objects in our $NB921$-excess sample and identified at least nine Ly$\alpha$ emitters at $z \sim 6.5$ -- 6.6 including the two emitters reported by Kodaira et al. (2003). Since our Ly$\alpha$ emitter candidates are free from strong amplification of gravitational lensing, we are able to discuss their observational properties from a statistical point of view. Based on these new results, we obtain a lower limit of the star formation rate density of $\rho_{\rm SFR} \simeq 5.5 \times 10^{-4}$ $h_{0.7}$ $M_\odot$ yr$^{-1}$ Mpc$^{-3}$ at $z \approx 6.6$, being consistent with our previous estimate. We discuss the nature of star-formation activity in galaxies beyond $z=6$.Comment: 49 pages, 16 figures, PASJ, Vol. 57, No. 1, in pres

Study of the sleep patterns, sleep habits, and sleep problems in Japanese elementary school children using the CSHQ-J

Objective: This study aimed to examine the sleep patterns, sleep habits, and sleep problems in Japanese elementary school children from the aspect of their developmental age. Methods: The Japanese version of the Children's Sleep Habits Questionnaire (CSHQ-J) was distributed to the parents of 330 students of which 296 (154 boys and 142 girls) questionnaires were returned. The subjects were divided into 3 groups by grade (Low-grade [1st−2nd graders], Middle-grade [3rd−4th graders], and High-grade [5th−6th graders]). Results: Bedtime was significantly later and sleep duration was significantly shorter in the older students. The total CSHQ-J score was significantly higher in the Low-grade group compared with that in the High-grade group. Regarding the sub-items of the CSHQ-J, the scores for "bedtime resistance" and "sleep anxiety" were significantly higher in the Low-grade group compared with those in the High-grade group. Conclusions: That sleep duration was significantly shorter in the older students was attributable to their later bedtimes. Differences in the total and sub-item scores of the CSHQ-J were largely attributable to the autonomy of sleep

The End of the Reionization Epoch Probed by Ly-alpha Emitters at z=6.5 in the Subaru Deep Field

We report an extensive search for Lyman-alpha emitters (LAEs) at z=6.5 in the Subaru Deep Field. Subsequent spectroscopy with Subaru and Keck identified eight more LAEs, giving a total of 17 spectroscopically confirmed LAEs at z=6.5. Based on this spectroscopic sample of 17, complemented by a photometric sample of 58 LAEs, we have derived a more accurate Lyman-alpha luminosity function of LAEs at z=6.5, which reveals an apparent deficit at the bright end of ~0.75 mag fainter L*, compared with that observed at z=5.7. The difference in the LAE luminosity functions between z=5.7 and 6.5 is significant at the 3-sigma level, which is reduced to 2-sigma when cosmic variance is taken into account. This result may imply that the reionization of the universe has not been completed at z=6.5. We found that the spatial distribution of LAEs at z=6.5 was homogeneous over the field. We discuss the implications of these results for the reionization of the universe.Comment: To appear in APJ vol.648. Only minor corrections have been made. Black&White version is available at http://zone.mtk.nao.ac.jp/~kashik/sdf/z6p5lae/paper/sdf_z6p5lae_bw.pd

A Search for Lyman alpha Emitters at Redshift 3.7

We present the results of a survey for emission-line objects based on optical intermediate-band ($\lambda_{\rm c}$ = 5736 \AA ~ and $\Delta\lambda$ = 280 \AA) and broad-band ($B$, $V$, $R$, and $i^\prime$) observations of the Subaru/XMM-Newton Deep Field on the 8.2 m Subaru telescope with the Subaru Prime Focus Camera, Suprime-Cam. All the data were obtained during the guaranteed time observations of the Suprime-Cam instrument. The intermediate-band image covered a sky area with 10\minpoint62 \times 12\minpoint40 \approx 132 arcmin$^2$ in the Subaru/XMM-Newton Deep Field (Ouchi et al.). Using this image, we have found 23 emission-line sources whose observed emission-line equivalent widths are greater than 250 \AA. Their optical multicolor properties indicate that six emission-line sources are Ly$\alpha$ emitters at $z \approx$ 3.7 ($\Delta z \approx 0.22$). They are either intense starburst galaxies or active galactic nuclei like quasars at $z \approx$ 3.7. Two more emission-line sources may also be Ly$\alpha$ emitters at $z \approx$ 3.7 although their multicolor properties are marginal. Among the remaining 15 emission-line objects, eight objects appear strong emission-line galaxies at lower redshift; e.g., [O {\sc ii}] $\lambda$3727 emitters at $z \approx 0.54$, H$\beta$ at $z \approx 0.18$, or [O {\sc iii}]$\lambda$5007 emitters at $z \approx 0.15$. The remaining seven objects are unclassified because they are too faint to be detected in broad-band images. We discuss observational properties of these strong emission-line sources. In particular, our data allow us to estimate the star formation density at $z \approx 3.7$ for the first time.Comment: Accepted for publication in AJ;14 pages, 26 figures (all figures are JPEG file

Clustering of Lyman Break Galaxies at z=4 and 5 in The Subaru Deep Field: Luminosity Dependence of The Correlation Function Slope

We explored the clustering properties of Lyman Break Galaxies (LBGs) at z=4 and 5 with an angular two-point correlation function on the basis of the very deep and wide Subaru Deep Field data. We found an apparent dependence of the correlation function slope on UV luminosity for LBGs at both z=4 and 5. More luminous LBGs have a steeper correlation function. To compare these observational results, we constructed numerical mock LBG catalogs based on a semianalytic model of hierarchical clustering combined with high-resolution N-body simulation, carefully mimicking the observational selection effects. The luminosity functions for LBGs predicted by this mock catalog were found to be almost consistent with the observation. Moreover, the overall correlation functions of LBGs were reproduced reasonably well. The observed dependence of the clustering on UV luminosity was not reproduced by the model, unless subsamples of distinct halo mass were considered. That is, LBGs belonging to more massive dark haloes had steeper and larger-amplitude correlation functions. With this model, we found that LBG multiplicity in massive dark halos amplifies the clustering strength at small scales, which steepens the slope of the correlation function. The hierarchical clustering model could therefore be reconciled with the observed luminosity-dependence of the angular correlation function, if there is a tight correlation between UV luminosity and halo mass. Our finding that the slope of the correlation function depends on luminosity could be an indication that massive dark halos hosted multiple bright LBGs (abridged).Comment: 16 pages, 17 figures, Accepted for publication in ApJ, Full resolution version is available at http://zone.mtk.nao.ac.jp/~kashik/sdf/acf/sdf_lbgacf.pd

Completing the Census of Ly-alpha Emitters at the Reionization Epoch

We carried out extended spectroscopic confirmations of Ly-alpha emitters (LAEs) at z=6.5 and 5.7 in the Subaru Deep Field. Now, the total number of spectroscopically confirmed LAEs is 45 and 54 at z=6.5 and 5.7, respectively, and at least 81% (70%) of our photometric candidates at z=6.5 (5.7) have been spectroscopically identified as real LAEs. We made careful measurements of the Ly-alpha luminosity, both photometrically and spectroscopically, to accurately determine the Ly-alpha and rest-UV luminosity functions (LFs). The substantially improved evaluation of the Ly-alpha LF at z=6.5 shows an apparent deficit from z=5.7 at least at the bright end, and a possible decline even at the faint end, though small uncertainties remain. The rest-UV LFs at z=6.5 and 5.7 are in good agreement, at least at the bright end, in clear contrast to the differences seen in the Ly-alpha LF. These results imply an increase in the neutral fraction of the intergalactic medium from z=5.7 to 6.5. The rest-frame equivalent width (EW_0) distribution at z=6.5 seems to be systematically smaller than z=5.7, and it shows an extended tail toward larger EW_0. The bright end of the rest-UV LF can be reproduced from the observed Ly-alpha LF and a reasonable EW_0-UV luminosity relation. Integrating this rest-UV LF provides the first measurement of the contribution of LAEs to the photon budget required for reionization. The derived UV LF suggests that the fractional contribution of LAEs to the photon budget among Lyman break galaxies significantly increases towards faint magnitudes. Low-luminosity LAEs could dominate the ionizing photon budget, though this inference depends strongly on the uncertain faint-end slope of the Ly-alpha LF.Comment: 19 pages, 14 figures. Accepted for publication in Ap

Imaging uranium distribution on rat kidney sections through detection of alpha tracks using CR-39 plastic nuclear track detector

Uranium is renowned as a global contaminant, and attracts major concern with regards to the health risks involved because its nephrotoxicity. This paper discusses the development of a simple method to identify accumulated regions or localized sites of uranium within kidneys using the CR-39 plastic nuclear track detector. To demonstrate the proposed method, renal cryo-sections (5 μm-t) from Wistar male rats, subcutaneously administered with uranyl acetate (2 mg/kg), were prepared on day one after administration. Concerned sections were subsequently placed on CR-39, stored for 1.25 years, and then etched in a 7 M NaOH solution at 70 ℃ for 3 h. α-tracks were then detected in the form of etch pits, corresponding to uranium, and also the tissue shape and structure were transferred as a roughness on the surface of CR-39. As observed, the proposed method served to facilitate simultaneous detection and identification of localized regions of uranium accumulation within kidneys

A method for imaging of uranium distribution on rat kidney sections by detection of α-particle tracks using CR-39 plastic nuclear track detectors.

Uranium (U) is known as a global contaminant and is a major concern for health risk due to its high toxicity. In this study, our aim was to develop a possible simple method to identify accumulated regions or localized sites of U in kidney using CR-39 plastic nuclear track detector. To demonstrate our method, the renal cryo-sections (5 μm-t) from Wistar male rats (10 weeks old) administered with U-acetate (2 mg/kg) subcutaneously were prepared on day one after administration. The section were placed on CR-39, stored for one year and then etched in a 7 M NaOH solution at 70 ° C for 3 hours to visualize the α-tracks. Addition to the detection of α-tracks, the difference of UV light absorption of tissue structure affected the bulk etch velocity resulted surface roughness of CR-39 that represented tissue structure.As a result, total of 2449 α-tracks were detected in analyzed area of 144 mm2. The cortex (CO), the outer stripe of the outer medulla (OSOM), and the medulla were measured to be 77.2 mm2, 39.4 mm2, 22.7 mm2 from the HE-stained image and were identical with the transferred tissue relief on the CR-39. Number of α-tracks detected in CO and OSOM were 345 and 1986, indicating that the accumulation of U was nearly 6-fold higher in OSOM than CO. As conclusion, this method made possible to simultaneously identify the U accumulation region in the tissue section depending on the trajectory of α-tracks.Micros 2017 - 17th International Symposium on Microdosimetr

Relationship between the serum cancer antigen 125 level and the weight of surgically enucleated adenomyosis

Elevated serum levels of cancer antigen 125 (CA125) are known to occur in adenomyosis. However, the relationship between the severity of adenomyosis and serum CA125 levels has not yet been elucidated. The present study aimed to examine the correlation between the weight of adenomyosis and the serum CA125 level. This retrospective study, after applying exclusion criteria, investigated 308 patients who underwent conservative surgery for adenomyosis. Serum CA125 levels were measured before surgery and weights of surgically enucleated adenomyosis were measured in the operating room. Both serum CA125 and surgically enucleated adenomyosis weight showed log-normal distributions. Pearson’s product-moment correlation coefficient for the logarithmically converted values was 0.617 (95% confidence interval, 0.54–0.68). The serum CA125 level correlated positively with the weight of adenomyosis. Although the qualitative characteristics and clinical significance of adenomyosis lesions remain unclear, it seems that the investigation of the relative relationship between the serum CA125 level and the size of the affected lesion is useful to observe one of the qualitative features of adenomyosis. Furthermore, the present study supports the use of postoperative serum CA125 levels as an important indicator for determining the therapeutic effects of conservative surgical treatment for adenomyosis and detecting early signs of recurrence. Impact Statement What is already known on this subject? Elevated serum cancer antigen 125 (CA125) levels are known to occur in adenomyosis and are widely recognised as helpful in the diagnosis of adenomyosis. What do the results of this study add? There is a positive correlation between the serum CA125 level and the weight of adenomyosis. What are the implications of these findings for clinical practice and/or further research? The postoperative serum CA125 level is an important indicator for evaluating the extent of the affected lesion remaining after conservative surgical treatment for adenomyosis and also helpful for detecting early signs of recurrence. Further study is required to examine whether it is possible to clarify the qualitative characteristics of adenomyosis in each different case based on the CA125-producing ability of the lesion

Formation of lipid droplets induced by 2,3-dihydrogeranylgeranoic acid distinct from geranylgeranoic acid

Geranylgeranoic acid (GGA) and 2,3-dihydrogeranylgeranoic acid (2,3-diGGA) are geranylgeraniol-derived metabolites (Kodaira et al. (2002) J Biochem 132: 327-334). In the present study, we examined the effects of these acids on HL-60 cells. The cells were differentiated into neutrophils by GGA stimulation like retinoic acid stimulation. In the case of cells stimulated with 2,3-diGGA, neutrophils were not detected, but the formation of lipid droplets was induced. On the other hand, when the cells were cultured in the presence of 0.1% FBS instead of 10% FBS, apoptotic cells were induced not only by GGA stimulation but also with 2,3-diGGA. In the latter case, when the cells were cultured in the co-presence of a caspase-3 inhibitor (Ac-DMQD-CHO), the lipid droplets formation was observed in the cells. These results suggest that GGA and 2,3-diGGA are extremely different from each other with respect to their effects on HL-60 cells