Developmental trajectories of ethnic and national identities in adolescents from migrant families: The role of social identification with family and classmates

Given that adolescents from migrant families live within at least two cultural contexts (i.e., the heritage and the destination cultures), they generally must negotiate and construct ethnic and national identities. Accordingly, the present three-wave longitudinal study was designed to identify distinct developmental trajectories of ethnic and national identities among adolescents from migrant families (n = 244, 56.6% female; Mage = 14.90, SDage = 0.84 at Time 1). Multivariate latent class growth analyses indicated that participants could be classified into one of four groups based on their identity profiles: ethnic-oriented identity, national-oriented identity, dual identity, and marginalized identity. Further, social identification with family and classmates was examined as a predictor of memberships in these distinct identity profiles. Results of multinomial logistic regression analysis indicated that greater social identification with family increased the probability of being classified into the ethnic-oriented and dual identity profiles rather than into the marginalized identity profile, whereas greater social identification with classmates increased the likelihood of being classified into either national-oriented or dual identity profiles rather than into the marginalized identity profile. These findings provide novel insights into the roles of families and peers as influential socializing agents during the negotiation of ethnic and national identities among immigrant youth

Meeting in school: Cultural diversity approaches of teachers and intergroup contact among ethnic minority and majority adolescents

This study investigated the associations between cultural diversity approaches endorsed by teachers and adolescents' positive and negative intergroup contact in schools. Participants were 984 adolescents (Mage = 14.66; 62.7% female; 24.8% ethnic minority) involved in a three-wave longitudinal study between 2019 and 2020. Results highlighted that perceived equal treatment by teachers was related to higher positive and lower negative contact over time. However, perceived support for contact and cooperation and interest of teachers in children's cultural background were not related to either positive or negative contact over time. Importantly, the results were replicated across ethnic minority and majority adolescents. This study provides novel insights into the key role that teachers can play in promoting cultural diversity approaches to facilitate harmonious intergroup interactions in schools

Minimally invasive management of vital teeth requiring root canal therapy

The present study aimed to investigate the possible use of a non-instrumentation technique including blue light irradiation for root canal cleaning. Extracted human single rooted teeth were selected. Nine different groups included distilled water, NaOCl, intra-canal heated NaOCl, and NaOCl + EDTA irrigation after either instrumentation or non-instrumentation, and a laser application group following non-instrumentation technique. The chemical assessment of the root canal dentine was evaluated using EDS and FT-IR. Surface microstructural analyses were performed by using SEM. The antimicrobial efficacy of different preparation techniques was evaluated using microbial tests. Laser application didn’t change the Ca/P, carbonate/phosphate and amide I/phosphate ratios of the root canal dentin the root canal dentin preserved its original form after light application. The instrumentation decreased the carbonate/phosphate and amide I/phosphate ratios of the root canal dentin regardless of the irrigation solution or technique (p < 0.05). According to the microbiological tests, the light application could not provide antibacterial efficacy as much as NaOCl irrigation. The NaOCl irrigation both in the non-instrumentation and instrumentation groups significantly reduced the number of bacteria (p < 0,05). Minimally invasive root canal preparation techniques where the root canal is not instrumented and is disinfected by laser irradiation followed by obturation with a hydraulic cement sealer may be an attractive treatment option for management of vital teeth needing root canal therapy and does not have any detrimental effects on the chemical structure of dentin

Evaluation of the genotoxicity and cytotoxicity in the buccal epithelial cells of patients undergoing orthodontic treatment with three light-cured bonding composites by using micronucleus testing

Objective: This study evaluated the cytotoxicity and genotoxicity of fixed orthodontic treatment with three different light-cured orthodontic bonding composites by analyzing micronucleus (MN) formation in the buccal mucosa during a 6-month period. Methods: Thirty healthy volunteers were selected from consecutive patients referred for orthodontic treatment. Equilibrium 2 brackets and molar tubes (Dentaurum) were bonded with three different lightcured orthodontic bonding composites-Transbond XT (3M Unitek), Kurasper F (Kuraray Europe), or GrenGloo (Ormco Corporation)- to all teeth in both arches. Exfoliated buccal epithelial cells were scraped from the middle part of the inner cheeks with sterile cement spatulas before treatment and at 1, 3, and 6 months after treatment. MNs and nuclear alterations, such as karyorrhexis (KR), karyolysis (KL), and binucleated cells (BNs), were scored under a light microscope. Repeated measure ANOVA was used to calculate statistical differences in degenerative nuclear abnormalities. Results: MN rates did not significantly differ among different time points within the same cell type (p > 0.05). In contrast, the number of BNs in buccal epithelial cells significantly increased in all composite groups (p < 0.01, Transbond XT; p < 0.001, Kurasper F and GrenGloo). KL frequency significantly increased between the beginning and end of the study in the Kurasfer F (0.80 ± 0.79 to 1.90 ± 1.10; p < 0.05) and GrenGloo (1.30 ± 1.06 to 2.40 ± 1.08; p < 0.05) groups. Conclusions: After 6 months of fixed orthodontic treatment with different light-cured composites, morphological signs of cytotoxicity were observed but genotoxic effects were absent. © 2014 The Korean Association of Orthodontists

Absolute dimensions of eclipsing binaries. XXVIII. BK Pegasi and other F-type binaries: Prospects for calibration of convective core overshoot

We present a detailed study of the F-type detached eclipsing binary BK Peg, based on new photometric and spectroscopic observations. The two components, which have evolved to the upper half of the main-sequence band, are quite different with masses and radii of (1.414 +/- 0.007 Msun, 1.988 +/- 0.008 Rsun) and (1.257 +/- 0.005 Msun, 1.474 +/- 0.017 Rsun), respectively. The 5.49 day period orbit of BK Peg is slightly eccentric (e = 0.053). The measured rotational velocities are 16.6 +/- 0.2 (primary) and 13.4 +/- 0.2 (secondary) km/s. For the secondary component this corresponds to (pseudo)synchronous rotation, whereas the primary component seems to rotate at a slightly lower rate. We derive an iron abundance of [Fe/H] =-0.12 +/- 0.07 and similar abundances for Si, Ca, Sc, Ti, Cr and Ni. Yonsei-Yale and Victoria-Regina evolutionary models for the observed metal abundance reproduce BK Peg at ages of 2.75 and 2.50 Gyr, respectively, but tend to predict a lower age for the more massive primary component than for the secondary. We find the same age trend for three other upper main-sequence systems in a sample of well studied eclipsing binaries with components in the 1.15-1.70 Msun range, where convective core overshoot is gradually ramped up in the models. We also find that the Yonsei-Yale models systematically predict higher ages than the Victoria-Regina models. The sample includes BW Aqr, and as a supplement we have determined a [Fe/H] abundance of -0.07 +/- 0.11 for this late F-type binary. We propose to use BK Peg, BW Aqr, and other well-studied 1.15-1.70 Msun eclipsing binaries to fine-tune convective core overshoot, diffusion, and possibly other ingredients of modern theoretical evolutionary models.Comment: Accepted for publication in Astronomy and Astrophysic

MnOx-Promoted PdAg Alloy Nanoparticles for the Additive-Free Dehydrogenation of Formic Acid at Room Temperature

Formic acid (HCOOH) has a great potential as a safe and a convenient hydrogen carrier for fuel cell applications. However, efficient and CO-free hydrogen production through the decomposition of formic acid at low temperatures (&lt;363 K) in the absence of additives constitutes a major challenge. Herein, we present a new heterogeneous catalyst system composed of bimetallic PdAg alloy and MnOx nanoparticles supported on amine-grafted silica facilitating the liberation of hydrogen at room temperature through the dehydrogenation of formic acid in the absence of any additives with remarkable activity (330 mol H2·mol catalyst-1·h-1) and selectivity (&gt;99%) at complete conversion (&gt;99%). Moreover this new catalytic system enables facile catalyst recovery and very high stability against agglomeration, leaching, and CO poisoning. Through a comprehensive set of structural and functional characterization experiments, mechanistic origins of the unusually high catalytic activity, selectivity, and stability of this unique catalytic system are elucidated. Current heterogeneous catalytic architecture presents itself as an excellent contender for clean hydrogen production via room-temperature additive-free dehydrogenation of formic acid for on-board hydrogen fuel cell applications. © 2015 American Chemical Society

X-ray luminosity function of faint point sources in the Milky Way

We assess the contribution to the X-ray (above 2 keV) luminosity of the Milky Way from different classes of low-mass binary systems and single stars. We begin by using the RXTE Slew Survey of the sky at |b|>10 to construct an X-ray luminosity function (XLF) of nearby X-ray sources in the range 10^30<Lx(erg/s)<10^34 (where Lx is the luminosity over 2-10 keV), occupied by coronally active binaries (ABs) and cataclysmic variables (CVs). We then extend this XLF down to Lx~10^27.5 erg/s using the Rosat All-Sky Survey in soft X-rays and available information on the 0.1-10 keV spectra of typical sources. We find that the local cumulative X-ray (2-10 keV) emissivities (per unit stellar mass) of ABs and CVs are (2.0+/-0.8)x10^27 and (1.1+/-0.3)x10^27 erg/s/Msol, respectively. In addition to ABs and CVs, representing old stellar populations, young stars emit locally (1.5+/-0.4)x10^27 erg/s/Msol. We finally attach to the XLF of ABs and CVs a high luminosity branch (up to ~10^39 erg/s) composed of neutron-star and black-hole low-mass X-ray binaries (LMXBs), derived in previous work. The combined XLF covers ~12 orders of magnitude in luminosity. The estimated combined contribution of ABs and CVs to the 2-10 keV luminosity of the Milky Way is ~2x10^38 erg/s, or ~3% of the integral luminosity of LMXBs (averaged over nearby galaxies). The XLF obtained in this work is used elsewhere (Revnivtsev et al.) to assess the contribution of point sources to the Galactic ridge X-ray emission.Comment: 14 pages, 13 figures, revised version accepted for publication in A&

Increased Risk of Vascular Events in Emergency Room Patients Discharged Home with Diagnosis of Dizziness or Vertigo: A 3-Year Follow-Up Study

BACKGROUND: Dizziness and vertigo symptoms are commonly seen in emergency room (ER). However, these patients are often discharged without a definite diagnosis. Conflicting data regarding the vascular event risk among the dizziness or vertigo patients have been reported. This study aims to determine the risk of developing stroke or cardiovascular events in ER patients discharged home with a diagnosis of dizziness or vertigo. METHODOLOGY: A total of 25,757 subjects with at least one ER visit in 2004 were identified. Of those, 1,118 patients were discharged home with a diagnosis of vertigo or dizziness. A Cox proportional hazard model was performed to compare the three-year vascular event-free survival rates between the dizziness/vertigo patients and those without dizziness/vertigo after adjusting for confounding and risk factors. RESULTS: We identified 52 (4.7%) vascular events in patients with dizziness/vertigo and 454 (1.8%) vascular events in patients without dizziness/vertigo. ER patients discharged home with a diagnosis of vertigo or dizziness had 2-fold (95% confidence interval [CI], 1.35-2.96; p<0.001) higher risk of stroke or cardiovascular events after adjusting for patient characteristics, co-morbidities, urbanization level of residence, individual socio-economic status, and initially taking medications after the onset of dizziness or vertigo during the first year. CONCLUSIONS: ER patients discharged home with a diagnosis of dizziness or vertigo were at a increased risk of developing subsequent vascular events than those without dizziness/vertigo after the onset of dizziness or vertigo. Further studies are warranted for developing better diagnostic and follow-up strategies in increased risk patients