Stars were born in significantly denser regions in the early Universe

The density of the warm ionized gas in high-redshift galaxies is known to be higher than what is typical in local galaxies on similar scales. At the same time, the mean global properties of the high- and low-redshift galaxies are quite different. Here, we present a detailed differential analysis of the ionization parameters of 14 star-forming galaxies at redshift 2.6-3.4, compiled from the literature. For each of those high-redshift galaxies, we construct a comparison sample of low-redshift galaxies closely matched in specific star formation rate (sSFR) and stellar mass, thus ensuring that their global physical conditions are similar to the high-redshift galaxy. We find that the median log [OIII] 5007/ [OII] 3727 line ratio of the high-redshift galaxies is 0.5 dex higher than their local counterparts. We construct a new calibration between the [OIII] 5007/ [OII] 3727 emission line ratio and ionization parameter to estimate the difference between the ionization parameters in the high and low-redshift samples. Using this, we show that the typical density of the warm ionized gas in star-forming regions decreases by a median factor of $7.1^{+10.2}_{-5.4}$ from z ~ 3.3 to z ~ 0 at fixed mass and sSFR. We show that metallicity differences cannot explain the observed density differences. Because the high- and low-redshift samples are comparable in size, we infer that the relationship between star formation rate density and gas density must have been significantly less efficient at z ~2-3 than what is observed in nearby galaxies with similar levels of star formation activity.Comment: 16 pages, 6 figures, accepted for publication in Ap

Comparison between Impact factor, SCImago journal rank indicator and Eigenfactor score of nuclear medicine journals

Despite its widespread acceptance in the scientific world, impactfactor (IF) has been criticized recently on many accounts:including lack of quality assessment of the citations, influenceof self citation, English language bias, etc. In the current study,we evaluated three indices of journal scientific impact: (IF),Eigenfactor Score (ES), and SCImago Journal rank indicator(SJR) of nuclear medicine journals. Overall 13 nuclear medicinejournals are indexed in ISI and SCOPUS and 7 in SCOPUSonly. Self citations, Citations to non-English articles, citationsto non-citable items and citations to review articles contributeto IFs of some journals very prominently, which can be betterdetected by ES and SJR to some extent. Considering all threeindices while judging quality of the nuclear medicine journalswould be a better strategy due to several shortcomings of IF.Despite its widespread acceptance in the scientific world, impactfactor (IF) has been criticized recently on many accounts:including lack of quality assessment of the citations, influenceof self citation, English language bias, etc. In the current study,we evaluated three indices of journal scientific impact: (IF),Eigenfactor Score (ES), and SCImago Journal rank indicator(SJR) of nuclear medicine journals. Overall 13 nuclear medicinejournals are indexed in ISI and SCOPUS and 7 in SCOPUSonly. Self citations, Citations to non-English articles, citationsto non-citable items and citations to review articles contributeto IFs of some journals very prominently, which can be betterdetected by ES and SJR to some extent. Considering all threeindices while judging quality of the nuclear medicine journalswould be a better strategy due to several shortcomings of IF

Investigating User Needs for Bio-sensing and Affective Wearables

Bio-sensing wearables are currently advancing to provide users with a lot of information about their physiological and affective states. However, relatively little is known about users' interest in acquiring, sharing and receiving this information and through which channels and modalities. To close this gap, we report on the results of an online survey (N=109) exploring principle aspects of the design space of wearables such as data types, contexts, feedback modalities and sharing behaviors. Results show that users are interested in obtaining physiological, emotional and cognitive data through modalities beyond traditional touchscreen output. Valence of the information, whether positive or negative affects the sharing behaviors

A New Three-Layer Model for Horizontal Slurry Flow

Paper presented at 2018 Canadian Society of Mechanical Engineers International Congress, 27-30 May 2018.A modified three-layer model for solid-liquid flow in horizontal pipes is developed, which overcomes the limitations of many previous models. The steady-state model predicts the pressure loss, critical velocity, concentration profile in the heterogeneous layer, mean heterogeneous layer and moving bed layer velocities, and bed layer heights for each set of parameters. We propose a new correlation for the turbulent solids diffusivity. This and the steady state model predictions show a good agreement with experimentally measured results in literature: for concentration profile in the heterogeneous layer and pressure loss, over a wide range of conditions [1]. In turbulent flow. the pressure loss vs mean velocity curve shows a characteristic minimum just before the critical velocity is attained

A smart rotary technique versus conventional pulpectomy for primary teeth : a randomized controlled clinical study

Techniques with adequate accuracy of working length determination along with shorter duration of treatment in pulpectomy procedure seems to be essential in pediatric dentistry. The aim of the present study was to evaluate the accuracy of root canal length measurement with Root ZX II apex locator and rotary system in pulpectomy of primary teeth. In this randomized control clinical trial complete pulpectomy was performed on 80 mandibular primary molars in 80, 4-6-year-old children. The study population was randomly divided into case and control groups. In control group conventional pulpectomy was performed and in the case group working length was determined by electronic apex locator Root ZXII and instrumented with Mtwo rotary files. Statistical evaluation was performed using Mann-Whitney and Chi-Square tests (P<0.05). There were no significant differences between electronic apex locator Root ZXII and conventional method in accuracy of root canal length determination. However significantly less time was needed for instrumenting with rotary files (P=0.000). Considering the comparable results in accuracy of root canal length determination and the considerably shorter instrumentation time in Root ZXII apex locator and rotary system, it may be suggested for pulpectomy in primary molar teeth