gebhart/patrepeval huggingface dataset:
Bridging the edtech evidence gap (2016)

Purpose – There are five factors acting as a barrier to the effective evaluation of educational technology (edtech), which are as follows: premature timing, inappropriate techniques, rapid change, complexity of context and inconsistent terminology. The purpose of this paper is to identify new evaluation approaches that will address these and reflect on the evaluation imperative for complex technology initiatives. Approach – An initial investigation of traditional evaluative approaches used within the technology domain was broadened to investigate the evaluation practices within social and public policy domains. Realist evaluation, a branch of theory-based evaluation, was identified and reviewed in detail. The realist approach was then refined, proposing two additional necessary steps to support mapping the technical complexity of initiatives. Findings – A refined illustrative example of a realist evaluation framework is presented, including two novel architectural edtech domain reference models to support mapping. Practical implications – Recommendations include building individual evaluator capacity; adopting the realist framework; the use of architectural edtech domain reference models; phased evaluation to first build theories in technology “context” and then iteratively during complex implementation chains; and community contribution to a shared map of technical and organisational complexity. Originality – This paper makes a novel contribution by arguing the imperative for a theory-based realist approach to help redefine evaluative thinking within the IT and complex system domain. It becomes an innovative proposal with the addition of two domain reference models that tailor the approach for edtech. Its widespread adoption will help build a shared evidence base that synthesizes and surfaces “what works, for whom, in which contexts and why”, benefiting educators, IT managers, funders, policymakers and future learners.
Virtualized Classroom - Automated Production, Media Integration and User-Customized Presentation (2005)

Multimedia materials from classrooms and seminars are rich sources of information. Our Virtualized Classroom Project, which is a testbed for integrating novel multimedia software systems, addresses fundamental research problems occurring in different components of a next-generation, processing-enhanced e-learning system. Our ultimate goal is to create a natural learning environment that could give students interactive experiences equivalent to, or even better than, the real classroom. This will be enabled by virtual instructor presence, user-selectable and fully-indexed visual aids, and flexible communications between students, the instructor and virtual instructors (computers). We have developed several basic components for the Virtualized Classroom project: automated data collection, intelligent media integration, and flexible user interfaces.
Kinetics of the direct borane reduction of pinacolone in THF (1997)

The kinetics of the borane reduction of the ketone pinacolone in THF depend strongly on the borane reagent. NaBH4, which is present in commercial BH3–THF as stabilizer, strongly catalyzes the reaction. The use of commercial BH3–THF results in the borane reaction order of 1.6. In contrast, freshly prepared, pure BH3–THF yields kinetics for which the main reaction, the reduction of the ketone by BH3–THF forming the monoalkoxyborane, are first order in both reactants. Two further subsequent reactions have to be included in the reaction scheme in order to fit the kinetics by numerical integration. Results of semiempirical calculations are compared with experimental findings to eludicate the possible reaction mechanism of the main reaction.
Dentine Tubule Occlusion by Novel Bioactive Glass-Based Toothpastes (2018)

There are numerous over-the-counter (OTC) and professionally applied (in-office) products and techniques currently available for the treatment of dentine hypersensitivity (DH), but more recently, the use of bioactive glasses in toothpaste formulations have been advocated as a possible solution to managing DH. <i>Aim</i>. The aim of the present study, therefore, was to compare several bioactive glass formulations to investigate their effectiveness in an established in vitro model. <i>Materials and Methods</i>. A 45S5 glass was synthesized in the laboratory together with several other glass formulations: (1) a mixed glass (fluoride and chloride), (2) BioMinF, (3) a chloride glass, and (4) an amorphous chloride glass. The glass powders were formulated into five different toothpaste formulations. Dentine discs were sectioned from extracted human teeth and prepared for the investigation by removing the cutting debris (smear layer) following sectioning using a 6% citric acid solution for 2 minutes. Each disc was halved to provide test and control halves for comparison following the brushing of the five toothpaste formulations onto the test halves for each toothpaste group. Following the toothpaste application, the test discs were immersed in either artificial saliva or exposed to an acid challenge. <i>Results</i>. The dentine samples were analyzed using scanning electron microscopy (SEM), and observation of the SEM images indicated that there was good surface coverage following artificial saliva immersion. Furthermore, although the acid challenge removed the hydroxyapatite layer on the dentine surface for most of the samples, except for the amorphous chloride glass, there was evidence of tubular occlusion in the dentine tubules. <i>Conclusions</i>. The conclusions from the study would suggest that the inclusion of bioactive glass into a toothpaste formulation may be an effective approach to treat DH.
Carrageenan induces interleukin-8 production through distinct Bcl10 pathway in normal human colonic epithelial cells (2006)

Carrageenan is a high molecular weight sulfated polygalactan used to improve the texture of commercial food products. Its use increased markedly during the last half century, although carrageenan is known to induce inflammation in rheumatological models and in intestinal models of colitis. We performed studies to determine its direct effects on human intestinal cells, including normal human intestinal epithelial cells from colonic surgeries, the normal intestinal epithelial cell line NCM460, and normal rat ileal epithelial cells. Cells were treated with high molecular weight lambda-carrageenan at a concentration of 1 mug/ml for 1-96 h. IL-8, IL-8 promoter activity, total and nuclear NF-kappaB, IkappaBalpha, phospho-IkappaBalpha, and Bcl10 were assessed by immunohistochemistry, Western blot, ELISA, and cDNA microarray. Increased Bcl10, nuclear and cytoplasmic NF-kappaB, IL-8 promoter activation, and IL-8 secretion were detected following carrageenan exposure. Knockdown of Bcl10 by siRNA markedly reduced the increase in IL-8 that followed carrageenan exposure in the NCM460 cells. These results show, for the first time, that exposure of human intestinal epithelial cells to carrageenan triggers a distinct inflammatory pathway via activation of Bcl10 with NF-kappaB activation and upregulation of IL-8 secretion. Since Bcl10 contains a caspase-recruitment domain, similar to that found in NOD2/CARD15 and associated with genetic predisposition to Crohn's disease, the study findings may represent a link between genetic and environmental etiologies of inflammatory bowel disease. Because of the high use of carrageenan as a food additive in the diet, the findings may have clinical significance.
The inhibitory effects of naringin on the growth of periodontal pathogens <i>in vitro</i> (2007)

Naringin is a flavonoid that is commonly found in grapefruits. The objective of this study was to evaluate the effects of naringin on the growth of periodontal pathogens such as A. actinomycetemcomitans and P. gingivalis in vitro. For comparison, the effects of naringin on several oral microbes were also studied. Different concentrations of naringin solution were added to calibrated suspensions of A. actinomycetemcomitans and P. gingivalis. All the suspensions were incubated for 3, 6 and 24 h in an anaerobic chamber at 37 degrees C. At each time point, selected dilutions from each culture broth were plated on blood agar plates. Colonies recovered on blood agar were visually counted on days 3 and 5, respectively. A. actinomycetemcomitans showed a significant decrease (p < 0.05) in viable counts after 3 h when naringin was added at baseline. P. gingivalis also showed a marked growth reduction in the presence of naringin, and no colony forming units could be observed after 24 h. Naringin also had an inhibitory effect against all bacteria and yeasts tested. The results suggest that naringin possesses significant antimicrobial properties on periodontal pathogens in vitro. It also has an inhibitory effect on some common oral microorganisms in low concentrations.
An Image Steganography Algorithm with Five Pixel Pair Differencing and Gray Code Conversion (2014)

Steganography involves hiding information in another media. PVD based steganography techniques uses the difference between the pixel values of a pair directly to hide the information. The proposed steganography system modifies the difference value before being used for hiding the information. This makes extraction of hidden data harder in case the steganography system fails. The algorithm divides the cover image in the block of 2 x 3 pixels and calculates average (N) of the bits that can be hidden in five pairs of that block. Thus if the difference value allows M-bits to be hidden in the pair, then only N-bits are hidden in that pair when M >N otherwise M (if MN) bits are hidden in that pair. Second level of security is added by converting the secret information into gray code before embedding it in the cover image. The algorithm provides good hiding capacity and improved quality of stego image with two levels of security for the secret information.
Spectrum of germline mutations in the RB1 gene: a study of 232 patients with hereditary and non hereditary retinoblastoma (1995)

Germline mutations in the RB1 gene confer hereditary predisposition to retinoblastoma. We have performed a mutation survey of the RB1 gene in 232 patients with hereditary or non hereditary retinoblastoma. We systematically explored all 27 exons and flanking sequences as well as the promotor. All types of point mutations are represented and are found unequally distributed along the RB1 gene sequence. In the population we studied, exons 3, 8, 18 and 19 are preferentially altered. The range of frequency of detection of germline mutations is about 20%, indicating that other mechanisms of inactivation of RB1 should be involved. The spectrum of mutations presented here should help to improve the clinical management of retinoblastoma and to understand the molecular mechanisms leading to tumorigenesis.
Novel transmission line combiner for highly efficient outphasing RF power amplifiers (2007)

A novel transmission line (TL) combiner is proposed having the same functionality as a Chireix-combiner with respect to its load impedance and combiner efficiency, but without the need of additional parallel compensating elements, which are necessary to improve the power backoff efficiency in highly efficient outphasing rf power amplifiers. Thus the design complexity is reduced and an alternative approach to Chireix-combiners becomes available. A detailed mathematical analysis of this TL- combiner is presented and design equations are derived. Its different physical operation and performance is demonstrated by a design example.
Relaxation of process induced surface stress in amorphous silicon carbide thin films using low energy ion bombardment (2006)

The surface stress in amorphous silicon carbide (a-SiC) thin films has been modified after processing. We show that low energy argon ion bombardment in an inductively coupled plasma reactor causes relaxation of the induced surface stress. Cantilever beams of variable length (25–150μm) have been fabricated and their deflection profiles have been compared before and after ion bombardment using white light interferometry. Our experiments show that the ion bombardment relaxes the stress gradient of the cantilever beams. Both the duration of plasma exposure as well as the bias voltage contribute to relaxing the stress gradient in the a-SiC thin film.
Reduced energy consumption and improved accuracy for distributed speech recognition in wireless environments (2004)

The central theme of this dissertation is the study of a multimedia client for pervasive wireless multimedia applications. Speech recognition is considered as one such application, where the computational demands have hindered its use on wireless mobile devices. Our analysis considers distributed speech recognition on hardware platforms with PDA-like functionality (i.e. wireless LAN networking, high-quality audio input/output, a low-power general-purpose processing core, and limited amounts of flash and working memory.) We focus on quality of service for the end-user (i.e. ASR accuracy and delay) and reduced energy consumption with increased battery lifetimes. We investigate quality of service and energy trade-offs in this context. We present software optimizations on a speech recognition front-end that can reduce the energy consumption by over 80% compared to the original implementation. A power on/off scheduling algorithm for the wireless interface is presented. This scheduling of the wireless interface can increase the battery lifetime by an order of magnitude. We study the effects of wireless networking and fading channel characteristics on distributed speech recognition using Bluetooth and IEEE 802.11b networks. When viewed as a whole, the optimized distributed speech recognition system can reduce the total energy consumption by over 95% compared to a client-side ASR implementation. We present an interleaving and loss concealment algorithm to increase the robustness of distributed speech recognition in a burst error channel. This improvement allows a decreased reliance on error protection overhead, which can provide reductions in transmit energy of up to 46% on a Bluetooth wireless network. The findings presented in this dissertation stress the importance of energy-aware design and optimization at all levels for battery-powered wireless devices.
Development of a flow chamber system for the reproducible in vitro analysis of biofilm formation on implant materials (2017)

Since the introduction of modern dental implants in the 1980s, the number of inserted implants has steadily increased. Implant systems have become more sophisticated and have enormously enhanced patients' quality of life. Although there has been tremendous development in implant materials and clinical methods, bacterial infections are still one of the major causes of implant failure. These infections involve the formation of sessile microbial communities, called biofilms. Biofilms possess unique physical and biochemical properties and are hard to treat conventionally. There is a great demand for innovative methods to functionalize surfaces antibacterially, which could be used as the basis of new implant technologies. Present, there are few test systems to evaluate bacterial growth on these surfaces under physiological flow conditions. We developed a flow chamber model optimized for the assessment of dental implant materials. As a result it could be shown that biofilms of the five important oral bacteria Streptococcus gordonii, Streptococcus oralis, Streptococcus salivarius, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans, can be reproducibly formed on the surface of titanium, a frequent implant material. This system can be run automatically in combination with an appropriate microscopic device and is a promising approach for testing the antibacterial effect of innovative dental materials.
Illumination encoding in face recognition: effect of position shift (2003)

Recognition of faces and objects is impaired when illumination direction varies. Three experiments explore whether this impairment can be explained by display changes (Biederman & Bar, 1999), and whether cast shadows help or hinder face recognition. Observers judged whether two sequentially-presented faces, shown with or without cast shadows, were the same person. The faces were illuminated from the same or different directions, and were presented in the same or different positions on the screen. In Experiment 1, performance was illumination-dependent only on same-position trials, suggesting that observers used display changes. Experiment 2 tested whether this could be explained by peripheral viewing on different-position trials. A fixation cross cued each face's location, such that observers could move their eyes to view each face centrally. Performance was illumination-dependent regardless of whether position changed. In both experiments, shadows did not affect performance, in contrast to earlier findings (Braje, Kersten, Tarr, & Troje, 1998). In Experiment 3, all faces were presented peripherally without shadows. Changing the illumination direction did not affect performance. These results demonstrate that peripheral viewing, rather than display changes, can explain why changes in illumination direction do not affect performance when position changes. The results also suggest that face representations retain illumination information.
Leucocyte-endothelial cell interactions (1992)

Leucocytes travel around the body in the blood vessels but, with the exception of platelets, must normally leave the bloodstream to exert their protective influence in the neighbouring tissues. To facilitate this, complex sets of interactions between the endothelium and different categories of leucocyte have evolved. Three of these sets of interactions are described in this overview: first, the steps involved in neutrophi| binding to, and extravasation through, endothelium during an inflammatory reaction; second, the mechanisms of attachment and activation of blood platelets on interaction with damaged blood vessels and third, the elaborate series of interactions between lymphocyte subpopulations and different types of endothelium in the control of lymphocyte recirculation patterns. In each of these areas, enormous progress has been made in recent years, such that the study of leucocyteendothelial cell interactions is an outstanding, arguably the best, example of the rapid application of developments in molecular and cell biology to an important aspect of immunophysiology.
The Effect of Distance From Pollinizer Varieties on the Fruit Set of Apple, Pear and Sweet-Cherry Trees (1964)

In a dwarf-pyramid apple orchard, rows of Cox’s Orange Pippin adjacent to rows of Janies Grieve had greater initial and final fruit sets than rows between other Cox rows. Flowers on the south sides of trees tended to have a greater set of fruit than those on the north sides.In a sweet-cherry orchard containing a block of five rows of Early Rivers with pollinizer rows on each side, most fruit was set on the two outside rows and least in the centre row. Trees in the outside rows set more fruit on their sides facing the pollinizers than on their far sides. In another sweet-cherry orchard, Frogmore trees set more fruit on their south sides than on the other parts.In a dwarf pyramid orchard of Comice, the trees with one graft of Conference (every tenth tree) set more fruit than trees without a graft. However, the fruit set on Conference dwarf and standard trees (two orchards of each) did not differ with their distance from pollinizers.
66.4: <i>Invited Paper</i> : Challenges and Opportunities in Scaling Up OLED Lighting Devices (2011)

Abstract In this paper we discuss the challenges involved in scaling from small size pixels to large area OLED lighting panels, with specific focus on panel luminance uniformity, resistive loss and lifetime. We also discuss panel design and report results for a 15 cm × 15 cm phosphorescent OLED (PHOLED) lighting panel.
Effect of hyperketonemia on chemokine secretion, adhesion molecule expression, and monocyte adhesion to endothelial cells (2010)

Frequent episodes of hyperketonemia are associated with higher incidences of vascular disease. We examined the hypothesis that hyperketonemia increases monocyte adhesion to endothelial cells (EC). Human U937 monocytes or THP‐1 monocytes and HUVECs were cultured with AA (0–10 mM) or BHB (0–10 mM) for 24 hours. Results ( ± SE) show that there was significant increase in IL‐8 and MCP‐1 secretion in AA treated THP‐1 and U937 monocytes and HUVECs, however, BHB had no effect. There was a 10.5% ± 0.04 (ns) increase in protein levels of LFA‐1 in 4 mM AA treated U937 monocytes compared to control and a 13% ± 4.3 (p<0.04) increase in surface expression. There was a 21% ± 3.5 (p<0.01) increase in CD14 surface expression on U937 and a 3.9% ± 1.8 (ns) in THP‐1 treated with 4 mM AA compared to control whereas BHB had no effect. Surface ICAM‐1 increased by 23.8% ± 0.02 (p<0.05) and total protein expression by 40% in HUVECs treated with 4 mM AA compared to the control. Results showed a 33.7% ± 2.3 (p<0.01) increase in U937 adhesion and a 23.5% ± 3.8 (p<0.05) increase in THP‐1 adhesion to HUVEC monolayer's treated with 4 mM AA compared to the control. Monocyte adhesion could be blocked by 14% ± 3.6 (p<0.04) when HUVEC's were pre‐incubated with ICAM‐1 antibody. Thus, hyperketonemia increases monocyte adhesion to EC's by upregulation of LFA‐1, CD‐14 and ICAM‐1, which may contribute to the excess vascular disease in diabetes.
Structure Formation of Integral-asymmetric Membranes of Polystyrene-block-poly(Ethylene Oxide) (2012)

For the first time the combination of solution casting and solvent–nonsolvent exchange (phase inversion) has been applied to generate asymmetric membranes with highly ordered hexagonally packed cylinders with perpendicular orientation composed of polystyrene-block-poly(ethylene oxide). The influence of parameters like solvent composition and evaporation time on the membrane formation is presented. The development is based on a study of the solution behavior by dynamic light scattering and the precipitation behavior of the cylinder forming diblock copolymer by turbidity measurements from different solvent and nonsolvent systems. The water flux properties, as an important membrane characteristic, show a time dependent behavior, due to swelling of the polyethylene oxide blocks. The morphologies of the membranes are imaged by scanning electron microscopy. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Rehabilitation of Sidi M’Cid Suspension Bridge, Algeria (2000)

The structural rehabilitation of the Sidi M’Cid suspension bridge in Constantine, Algeria, is presented. The bridge, designed by Arnodin in 1908 has a main span of 160 m and a mixed cable-supporting system with a stayed deck portion near the towers. Over time various components of the bridge had corroded, calling for structural rehabilitation that included partial replacement of the main suspension system as well as major interventions on both anchorages. Because the bridge spans a canyon 200 m deep, specifically designed equipment was required in order to partially replace the suspension system while maintaining the bridge under full service.
Tritium separation by CO2 laser multiphoton dissociation of trifluoromethane. (1980)

Click to increase image sizeClick to decrease image sizeKEYWORDS: isotope separationlaser isotope separationhydrogen isotopestritiuminfrared lasercarbon dioxide lasermultiphoton dissociationtrifluoromethaneradio gas chromatography