African Americans and boys: Understanding the literacy gap, tracing academic trajectories, and evaluating the role of learning-related skills.

In this study, the authors examined the racial and gender gap in the academic development of African American and White children from kindergarten to 5th grade. Their main goal was to determine the extent to which social and behavioral factors, including learning-related skills, problem behaviors, and interpersonal skills, explain these gaps and shed light on the academic difficulties specifically experienced by African American boys. The authors utilized the Early Childhood Longitudinal Study–Kindergarten Cohort (ECLS-K) sample and applied growth curve modeling. Learning-related skills explained the literacy development of African American boys over and above the effects of problem behaviors, socioeconomic status, and home literacy environment. Results suggest that emphasis placed on the behavior problems and the social risk factors associated with African American boys needs to be refocused and should be accompanied by increased efforts to improve learning-related skills in the classroom context and beyond. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Life-cycle assessment and repair of the railway transition zones of an existing bridge using geocomposite materials

The railway infrastructure is a very important component of the world’s total transportation network. Investment in its construction and maintenance is therefore significant on a global scale. Up to now, some results of the life-cycle assessment (LCA) of open railway line, as well as railway bridges and tunnels, have been published, but detailed analyses of transition zones have not so far been performed. In railway networks, transitional zones are a critical area where the transition from open rail to solid bridge construction can cause significant settlements. The goal of these analyses was to compare two different types of track renewal methods for railway transition zones. In the first method, traditional cement stabilisation is used, whereas the second solution makes use of a geocomposite anchored by steel anchors. The paper presents some results from an environmental study for railway transition zones based on the demonstration case. The results of the performed LCA showed that, in the case of track renewal for transition zones by means of a geocomposite and anchors, the environmental impact is lower than in the case when cement stabilisation works are performed. Less extensive excavation works and thus lower quantities of used material are additional benefits.     

Cobalt Ferrite Magnetic Nanoparticles for Tracing Mesenchymal Stem Cells in Tissue: A Preliminary Study

Therapy with mesenchymal stem cells (MSCs) is promising in many diseases. Evaluation of their efficacy depends on adequate follow-up of MSCs after transplantation. Several studies have shown that MSCs can be labeled and subsequently visualized with magnetic nanoparticles (NPs). We investigated the homing of MSCs labeled with magnetic cobalt ferrite NPs in experimentally induced acute kidney injury in mice. To explore the homing of MSCs after systemic infusion into mice, we developed a pre-infusion strategy for optimal tracing and identification of MSCs with polyacrylic acid-coated cobalt ferrite (CoFe₂O₄) NPs by light and transmission electron microscopy (TEM) in various organs of mice with cisplatin-induced acute kidney injury and control mice. By correlative microscopy, we detected MSCs labeled with NPs in the lungs, spleen, kidney, and intestine of cisplatin-treated mice and in the lungs and spleen of control mice. Our results confirm that labeling MSCs with metal NPs did not affect the ultrastructure of MSCs and their ability to settle in various organs. This study demonstrates the usefulness of cobalt ferrite NPs in ex vivo visualization of MSCs and offers correlative microscopy as a useful method in routine histopathology laboratories for tracing MSCs in paraffin-embedded tissue.     

Architecting play

From the grotesque pavilions hidden in sixteenth century Italian gardens to the temporary structures in public space in the 70s and recent digitally augmented environments, architectures of play have long been designed to engage explorative experiences. The uncertainty of play allows us to probe new behaviors, to poke into the boundaries of subjectivity and to interact with people, things and systems in unexpected and unfamiliar ways. In this essay, we explore how an interactive system, situated in public space, may foster explorative activities and enable the transformative power of play. Through the analysis of several computer-augmented architectures, we examine what interactive qualities might enhance the transformative power of play. Beginning with the Fun Palace, an early attempt to use cybernetics in order to encourage visitors to experiment with their habits, we move to contemporary projects including some of the author’s own work. The latter takes the advantage of existing public locations in order to insert exploratory play into everyday life. Through analysis of these projects, we discuss whether such environments raise our responsibility toward others within our surroundings; whether they enable us to transform our own established behaviors; and whether they empower us to reclaim public space.     

Life cycle assessment of a geosynthetic-reinforced soil bridge system – A case study

Road infrastructures are a very important component of the world's total transportation network. Investment in its construction and maintenance is significant on a global scale. The paper presents some results from an environmental study of a geosynthetic-reinforced soil integrated bridge system. The Pavlovski potok stream in Slovenia was used as a demonstration case for this study. It is the first GRS bridge system with full-height rigid (FHR) facings in Europe. It was constructed at the end of 2014. The goal of these analyses was to compare two different types of bridges: the new GRS bridge system, which is comprised of a simple girder partially structurally integrated to FHR facings of GRS bridge abutments and a conventional reinforced concrete road bridge. The results of an environmental life cycle assessment (LCA) show that the GRS bridge system has a much lower environmental impact than an equivalent bridge conventionally built with reinforced concrete.     

Optimisation of the amino–carboxy coupling of oligonucleotides to beads used in liquid arrays

Interest is increasing in the multiplexed bead‐based method to detect nucleic acid quantities, using oligonucleotides (oligos) coupled to micrometre‐sized polystyrene beads. This paper describes an evaluation of this coupling step by examining different buffers at various pHs and the effect of changing the oligo concentration. The use of 2‐(N‐morpholino)ethanesulfonic acid (MES)–borate buffer (pH 4.5) during the effective coupling step yielded the best coupling efficiency. The addition of 15 pmol of oligo to 10⁵ beads resulted in the highest number of coupled oligos per bead (～336 ± 28 oligos µm^?2). In addition, an alternative method to calibrate the fluorescence intensity by using FloSense Rainbow Calibration Particles was evaluated. In this way, it was possible to compare data independently of the type of flow cytometer used or the photomultiplier tube settings. Copyright © 2005 Society of Chemical Industry     

Impedance spectroscopy data for S2O8 anion electroreduction at Bi(1 1 1) plane

Electroreduction kinetics of the peroxodisulfate anions on the electrochemically polished Bi(1 1 1) single crystal electrode has been studied by impedance spectroscopy. Influence of the electrode potential, reaction intermediates, base electrolyte and reactant concentrations on the kinetic parameters of electroreduction has been established. Systematic analysis of the fitting results demonstrates the noticeable influence of adsorption of the reaction intermediate or reactant on the electroreduction rate of the S₂O₈²⁻ anions at the Bi(1 1 1) electrode. In the region of so-called “current pits” in the cyclic voltammetry curves, obtained by rotating disc electrode method, the mixed kinetics, i.e. the adsorption and “true” charge transfer limited steps have been established by impedance spectroscopy.     

Stability and transformation of products formed from dimeric dehydroascorbic acid at low pH

Dehydroascorbic acid dimer (DDHA) is the commercially available form of oxidised vitamin C. When DDHA enters an aqueous environment, it will interact with water, but the details of this process are not well defined. Hydration of DDHA was analyzed as a function of concentration, pH and temperature. Above pH 5 only hydrated dehydroascorbic acid monomer (DHA) and its degradation product 2,3-diketogulonic acid (DKG) were observed. At pH lower than 4 and in MilliQ water, relatively stable hydrated dimeric species were additionally detected. They are intermediates formed from DDHA and transformed into DKG, either directly or through DHA. A lower temperature of dissolution favours the formation of hydrated dimeric products, while the concentration of DDHA has no effect on their yield. All products were separated chromatographically and analyzed by three detectors: diode array, refractive index and electrospray ionisation mass spectrometry. The stability and transformations of products were studied in the mixture and in the isolated fractions. Two initially formed monohydrated products are transformed to a dihydrated product that is degraded to DHA and DKG. Once formed, the dihydrated product and one of the monohydrated products are sufficiently stable to be identified at neutral pH. All three hydrated products are interconvertible and can be also formed after dissolution of dried DHA.