Redshift constraints for RGB 0136+391 and PKS 0735+178 from deep optical imaging

We present the results of deep I-band imaging of two BL Lacerate objects, RGB 0136+391 and PKS 0735+178, during an epoch when the optical nucleus was in a faint state in both targets. In PKS 0735+178 we find a significant excess over a point source, which, if fitted by the de Vaucouleurs model, corresponds to a galaxy with I = 18.64 +- 0.11 and r_eff = 1.8 +- 0.4 arcsec. Interpreting this galaxy as the host galaxy of PKS 0735+178 we derive z = 0.45 +- 0.06 using the host galaxy as a "standard candle". We also discuss the immediate optical environment of PKS 0735+178 and the identity of the MgII absorber at z = 0.424. Despite of the optimally chosen epoch and deep imaging we find the surface brightness profile of RGB 0136+391 to be consistent with a point source. By determining a lower limit for the host galaxy brightness by simulations, we derive z > 0.40 for this target.Comment: 6 pages, 5 figures, accepted for publication in Astronomy & Astrophysic

Metal size distribution in rainfall and snowmelt-induced runoff from three urban catchments

The size distribution of metals transported by urban runoff has implications for treatment type and design, predicting their mobility and evaluating their potential impact on receiving waters. There is an urgent need to better understand the distribution of metals between fractions, particularly those in the sub-dissolved fractions. As a contribution to addressing this need, this study characterises the size distribution of Cd, Cr, Cu, Ni, V and Zn using conventional and novel techniques. Data is presented as event mean concentrations (EMC) of a total of 18 rainfall and snowmelt events at three urban sites. For all studied metals in all events and at all sites, the contribution of the truly dissolved fraction made a greater contribution to the total concentrations than the colloidal fraction. Truly dissolved Cd and Zn concentrations contributed (on average) 26% and 28% respectively, of the total EMCs with truly dissolved Cu and Ni contributing (on average) 18%. In contrast, only 1% (V) and 3% (Cr) were identified in the truly dissolved fraction. The greatest contribution of truly dissolved Cd, Cu and Zn concentrations (relative to total oncentrations) were reported during rainfall events. However, no seasonal differences were identified and differences between the sites regarding the EMCs distribution by fractions were not at a statistically significant level (p N 0.05) for any metal or event. The loads of truly dissolved and colloidal metals did not follow the patterns of particulate metal loads indicating particulates are not the main source of subdissolved metals. The data suggests that ultrafiltration as a treatment technique would not efficiently mitigate the risks posed by metals to receiving water cologie

Evaluation of measured dissolved and bio-met predicted bioavailable Cu, Ni and Zn concentrations in runoff from three urban catchments

Urban runoff is a diffuse source of pollution contributing to the poor ecological and chemical status of surface waters. Whilst the EU Priority Hazardous Substances Directive now identifies environmental quality standards for selected metals in relation to the bioavailable metal fraction the relationship between analytically determined metal size fractions transported by urban runoff and the often variably defined concept of bioavailability has not been thoroughly evaluated. This paper provides a review of the terminology used within urban runoff studies to characterise metal fractions and behaviour. Measured dissolved and truly dissolved (determined by ultrafiltration; <3000 molecular weight cutoff) Cu, Ni, and Zn concentrations are also compared to the bioavailable metal fraction (as predicted using Bio-met, a simplified biotic ligand model) in snowmelt and rainfall derived runoff samples from three urban catchments. The study shows that predicted bioavailable concentrations were significantly lower than truly dissolved concentrations for all metals and discusses current bioavailability modelling parameters in relation to rainfall and snowmelt runoff data sets. Statistical analysis of relationships between field and predicted bioavailable data sets indicate that the bioavailable fractions originate from both colloidal and truly dissolved fractions

The Jet and the Supernova in GRB990712

The optical light curve of the afterglow following the gamma-ray burst GRB990712 is re-examined. Recently published polarization measurements of that source require a collimated outflow geometry that in turn predicts a break in the light curve. We show that the V-band light curve is consistent with such a break and that the post-break light curve evolution is dominated by a supernova contribution

Low schoolwork engagement and schoolwork difficulties predict smoking in adolescence?

Low academic achievement has been associated with smoking but factors behind this association are poorly known. Such factors could include schoolwork disengagement and schoolwork difficulties. To assess the extent to which they contribute to the explanation of how health inequalities emerge, we study in a longitudinal design whether these have an independent effect on smoking or whether their effect is mediated through academic achievement. Longitudinal data were collected in the Helsinki metropolitan area, Finland in 2011 and 2014. Participants were seventh-graders (12 13 years, N=9497). In the follow-up, 6534 students reported their smoking status in the ninth grade (15 16 years). Smoking, schoolwork behavioural engagement, i.e. participation in academic activities, and disengagement, schoolwork difficulties and cognitive competence were self-reported by adolescents. Academic achievement was obtained from the Finnish national application register on upper secondary education. A mediation analysis was executed with bootstrapped confidence intervals. Higher schoolwork behavioural engagement and cognitive competence in the seventh grade predicted that adolescents were more likely not to smoke in the ninth grade (all P <0.001) while higher schoolwork disengagement and schoolwork difficulties predicted adolescents smoking (all P <0.001). The effects were mediated through academic achievement. Students behavioural disengagement with schoolwork and schoolwork difficulties are risks for smoking initiation. Their effect is mediated through poor school achievement. As smoking often continues in adulthood and poor school performance typically leads to lower education, schoolwork disengagement and difficulties in adolescence constitute potential pathways to inequalities in health.Peer reviewe

Polymer-coated bioactive glass S53P4 increases VEGF and TNF expression in an induced membrane model in vivo

The two-stage induced-membrane technique for treatment of large bone defects has become popular among orthopedic surgeons. In the first operation, the bone defect is filled with poly(methyl methacrylate) (PMMA), which is intended to produce a membrane around the implant. In the second operation, PMMA is replaced with autograft or allograft bone. Bioactive glasses (BAGs) are bone substitutes with bone-stimulating and angiogenetic properties. The aim of our study was to evaluate the inductive vascular capacity of BAG-S53P4 and poly(lactide-co-glycolide) (PLGA)-coated BAG-S53P4 for potential use as bone substitutes in a single-stage induced-membrane technique. Sintered porous rods of BAG-S53P4, PLGA-coated BAG-S53P4 and PMMA were implanted in the femur of 36 rabbits for 2, 4 and 8 weeks. The expression of vascular endothelial growth factor (VEGF) and tumor necrosis factor alpha (TNF) in the induced membranes of implanted materials was analyzed with real-time quantitative polymerase chain reaction and compared with histology. Both uncoated BAG-S53P4 and PLGA-coated BAG-S53P4 increase expression of VEGF and TNF, resulting in higher amounts of capillary beds, compared with the lower expression of VEGF and less capillary beads observed for negative control and PMMA samples. A significantly higher expression of VEGF was observed for PLGA-coated BAG-S53P4 than for PMMA at 8 weeks (p <0.036). VEGF and TNF expression in the induced membrane of BAG-S53P4 and PLGA-coated BAG-S53P4 is equal or superior to PMMA, the "gold standard" material used in the induced-membrane technique. Furthermore, the VEGF and TNF expression for PLGA-coated BAG-S53P4 increased during follow-up.Peer reviewe

S53P4 bioactive glass scaffolds induce BMP expression and integrative bone formation in a critical-sized diaphysis defect treated with a single-staged induced membrane technique

Surgical management of critical-sized diaphyseal defects involves multiple challenges, and up to 10% result in delayed or non-union. The two-staged induced membrane technique is successfully used to treat these defects, but it is limited by the need of several procedures and bone graft. Repeated procedures increase costs and morbidity, while grafts are subject to donor-site complications and scarce availability. To transform this two-staged technique into one graft-independent procedure, we developed amorphous porous scaffolds sintered from the clinically used bioactive glass S53P4. This work constitutes the first evaluation of such scaffolds in vivo in a critical-sized diaphyseal defect in the weight-bearing rabbit femur. We provide important knowledge and prospects for future development of sintered S53P4 scaffolds as a bone substitute. Critical-sized diaphysis defects are complicated by inherent sub-optimal healing conditions. The two staged induced membrane technique has been used to treat these challenging defects since the 1980 & rsquo;s. It involves temporary implantation of a membrane-inducing spacer and subsequent bone graft defect filling. A single-staged, graft-independent technique would reduce both socio-economic costs and patient morbidity. Our aim was to enable such single-staged approach through development of a strong bioactive glass scaffold that could replace both the spacer and the graft filling. We constructed amorphous porous scaffolds of the clinically used bioactive glass S53P4 and evaluated them in vivo using a critical sized defect model in the weight-bearing femur diaphysis of New Zealand White rabbits. S53P4 scaffolds and standard polymethylmethacrylate spacers were implanted for 2, 4, and 8 weeks. Induced membranes were confirmed histologically, and their osteostimulative activity was evaluated through RT-qPCR of bone morphogenic protein 2, 4, and 7 (BMPs). Bone formation and osseointegration were examined using histology, scanning electron microscopy, energy-dispersive X-ray analysis, and micro-computed tomography imaging. Scaffold integration, defect union and osteosynthesis were assessed manually and with X-ray projections. We demonstrated that S53P4 scaffolds induce osteostimulative membranes and produce osseointegrative new bone formation throughout the scaffolds. We also demonstrated successful stable scaffold integration with early defect union at 8 weeks postoperative in critical-sized segmental diaphyseal defects with implanted sintered amorphous S53P4 scaffolds. This study presents important considerations for future research and the potential of the S53P4 bioactive glass as a bone substitute in large diaphyseal defects. Statement of significance Surgical management of critical-sized diaphyseal defects involves multiple challenges, and up to 10% result in delayed or non-union. The two-staged induced membrane technique is successfully used to treat these defects, but it is limited by the need of several procedures and bone graft. Repeated procedures increase costs and morbidity, while grafts are subject to donor-site complications and scarce availability. To transform this two-staged technique into one graft-independent procedure, we developed amorphous porous scaffolds sintered from the clinically used bioactive glass S53P4. This work constitutes the first evaluation of such scaffolds in vivo in a critical-sized diaphyseal defect in the weight-bearing rabbit femur. We provide important knowledge and prospects for future development of sintered S53P4 scaffolds as a bone substitute. (c) 2021 The Author(s). Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )Peer reviewe