bluuebunny/crossref_metadata_2025 huggingface dataset:
Reshaping Distance Education
Authors: Todhunter Barrie
Published: July 2013

Teachers in higher education are confronted with a confusing and fragmented range of learning and teaching models for learners who are not traditional on-campus students. This chapter examines the development of guidelines to assist in the reshaping of a coursework Master’s program in project management offered at a regional university. Using a coursework program as a case study, a holistic exploration has been carried out of the critical issues associated with teaching and learning at a distance, with a focus on the three layers of the institutional environment, the pedagogical frameworks and the learning setting of the actual students. The research methodology and design are discussed and the outcomes are presented to provide guidance for administrators, teachers and learners. The major outcome of this study is a holistic framework of Distance Education Learning Principles for Higher Education (DELPHE) as a meaningful tool for reshaping postgraduate distance education learning and teaching models.
Communities of Practice for Distance Research Students in Australia
Authors: Redman Judith C. S.
Published: July 2013

The literature on best practice Higher Degree Research (HDR) supervision indicates that incorporation of candidates into communities of practice is an essential part of the process. This chapter reviews the literature and draws on the author’s experiences as a part-time HDR student and as someone whose employment has involved providing support for HDR students, highlighting the problems and possibilities involved in incorporating distance students into communities of practice, and proposing a way forward for the Australian context which would provide an action research possibility.
Lecturers’ Social Presence and Personality in the Online Environment
Authors: Valenzuela Fredy-Roberto , Fisher Josie , Whale Sue
Published: July 2013

The first aim of this chapter is to present a literature review regarding two very important concepts for the online learning environment: social presence and personality. The second aim is to present the findings of an exploratory study that measured students’ perceptions regarding different aspects of their experience with the online learning environment including social presence and personality of lecturers in the online environment in particular. An online survey (developed using Qualtrix) was emailed to 474 off-campus postgraduate and 699 undergraduate students who are pursuing a coursework degree in management. To date, 62 responses from postgraduate and 41 from undergraduate students have been received, which indicates a response rate of 13 percent and 5.9 percent, respectively. Results show that social presence is not being successfully developed by lecturers, with discussion boards and chat rooms showing relatively low evaluations. In terms of lecturers’ personalities in the online environment, results show that some lecturers do not have a clear structure for their discussion boards and chat rooms and that the language used by lecturers in the online environment (especially discussion boards and chat rooms) differs from their language in face-to-face contexts. Other online learning tools, such as special podcasts and special vodcasts, show less difference in the personality of lecturers in the online and face-to-face contexts, especially in terms of language and tone of voice used by lecturers.
Scanning-Based Interaction Techniques for Motor Impaired Users
Authors: Ntoa Stavroula , Margetis George , Antona Margherita , Stephanidis Constantine
Published: July 2013

Scanning is an interaction method addressing users with severe motor impairments which provides sequential access to the elements of a graphical user interface and enables users to interact with the interface through at least a single binary switch by activating the switch when the desired interaction element receives the scanning focus. This chapter explains the scanning technique and reports on related approaches across three contexts of use: personal computers, mobile devices, and environmental control for smart homes and ambient intelligence environments. In the context of AmI environments, a recent research approach combining head tracking and scanning techniques is discussed as a case study.
Design and Evaluation of Vision-Based Head and Face Tracking Interfaces for Assistive Input
Authors: Morikawa Chamin , Lyons Michael J.
Published: July 2013

Interaction methods based on computer-vision hold the potential to become the next powerful technology to support breakthroughs in the field of human-computer interaction. Non-invasive vision-based techniques permit unconventional interaction methods to be considered, including use of movements of the face and head for intentional gestural control of computer systems. Facial gesture interfaces open new possibilities for assistive input technologies. This chapter gives an overview of research aimed at developing vision-based head and face-tracking interfaces. This work has important implications for future assistive input devices. To illustrate this concretely the authors describe work from their own research in which they developed two vision-based facial feature tracking algorithms for human computer interaction and assistive input. Evaluation forms a critical component of this research and the authors provide examples of new quantitative evaluation tasks as well as the use of model real-world applications for the qualitative evaluation of new interaction styles.
Assistive Technology
Authors: Tran Ben
Published: July 2013

The purpose of this chapter is to analyze the history of motor disabled assistive technology. Specifically, this chapter will cover motor disability and the history of assistive technology related to motor disability. As such, this chapter will also include the evolution of technology and its components, resulting in the creation and development of assistive technology. Assistive technology will be defined and analyzed, the history of disabilities will be covered, and the history of motor disability will be discussed. Reasonable accommodations, based on the Americans with Disabilities Act (ADA), in relations to the utilization of assistive technology, in the disabled community, as well as in relations to the independence of the disabled will be covered via the paradigms of assistive technology trainer and job developer for the disabled in the United States of America—capital of technology—Google, Inc., Yahoo! Inc., Microsoft Corporation, Cisco Systems, Inc.—and capital of assistive technology.
Exploratory Point Pattern Analysis for Modeling Biological Data
Authors: Zimeras Stelios
Published: July 2013

Data in the form of sets of points, irregular distributed in a region of space could be identified in varies biological applications for examples the cell nuclei in a microscope section of tissue. These kinds of data sets are defined as spatial point patterns and the presentation of the positions in the space are defined as points. The spatial pattern generated by a biological process, can be affected by the physical scale on which the process is observed. With these spatial maps, the biologists will usually want a detailed description of the observed patterns. One way to achieve this is by forming a parametric stochastic model and fitting it to the data. The estimated values of the parameters could be used to compare similar data sets providing statistical measures for fitting models. Also a fitted model can provide an explanation of the biological processes. Model fitting especially for large data sets is difficult. For that reason, statistical methods can apply with main purpose to formulate a hypothesis for the implementation of biological process. Spatial statistics could be implemented using advance statistical techniques that explicitly analyses and simulates point structures data sets. Typically spatial point patterns are data that explain the location of point events. The author’s interest is the investigation of the significance of these patterns. In this work, an investigation of biological spatial data is analyzed, using advance statistical modeling techniques like kriging.
Spatial Uncertainty Analysis in Ecological Biology
Authors: Zimeras Stelios , Matsinos Yiannis
Published: July 2013

Uncertainty analysis is the part of risk analysis that focuses on the uncertainties in the data characteristics. Important components of uncertainty analysis include qualitative analysis that identifies the uncertainties, quantitative analysis of the effects of the uncertainties on the decision process, and communication of the uncertainty. (Funtowwicz & Ravetz 1990; Petersen, 2000; Regan et a1., 2002; Katz 2002). The analyses include simple descriptive procedures till quantitative estimation of uncertainty, and decision-based procedures. The analysis may be qualitative or quantitative, depending on the stage of analysis required and the amount of information available. When a neighbourhood structure lattice system is applied, a spatial connectivity between regions is defined where investigation of that structure includes modelling of the spatial homogeneity is introduced. Spatial investigation involves stochastic modelling especially in cases where the incomplete data involves hide information’s. In this work a spatial analysis methodology was introduced and procedures to solve the problem with spatial variability are described.
A New Genetic Algorithm for the RCPSP in Large Scale
Authors: Zoulfaghari Hossein , Nematian Javad , Mahmoudi Nader , Khodabandeh Mehdi
Published: July 2013

The Resource Constrained Project Scheduling Problem (RCPSP) is a well-studied academic problem that has been shown to be well suited to optimization via Genetic Algorithms (GA). In this paper, a new method will be designed that would be able to solve RCPSP. This research area is very common in industry especially when a set of activities needs to be finished as soon as possible subject to two sets of constraints, precedence constraints and resource constraints. The presented algorithm in this paper is used to solve large scale RCPSP and improves solutions. Finally, for comparing, results are reported for the most famous classical problems that are taken from PSPLIB.
Efficient Top-k Keyword Search Over Multidimensional Databases
Authors: Yu Ziqiang , Yu Xiaohui , Liu Yang
Published: July 2013

Keyword search over databases has recently received significant attention. Many solutions and prototypes have been developed. However, due to large memory consumption requirements and unpredictable running time, most of them cannot be applied directly to the situations where memory is limited and quick response is required, such as when performing keyword search over multidimensional databases in mobile devices as part of the OLAP functionalities. In this paper, the authors attack the keyword search problem from a new perspective, and propose a cascading top-k keyword search algorithm, which generates supernodes by a branch and bound method in each step of search instead of computing the Steiner trees as done in many existing approaches. This new algorithm consumes less memory and significantly reduces the response time. Experiments show that the method can achieve high search efficiency compared with the state-of-the-art approaches.
Collaborative Cross-Border Security Infrastructure and Systems
Authors: Luna-Reyes Luis Felipe , Derrick Douglas C. , Langhals Brent , Nunamaker Jay F.
Published: July 2013

A long-standing problem in the US-Mexico bilateral agenda is migration. Although both countries have important agreements to promote economic exchange and trade, the events of 9/11 and other acts of terrorism have increased concerns about border security. Since the US-Mexico border is one of the most important borders in the world in terms of activity, securing it without interfering with the legitimate flow of people and goods, poses an important challenge. The purpose of this paper is to propose conceptual frameworks and models to facilitate collaboration across national borders, by discussing and considering key factors for collaborative US-Mexico Border Security Infrastructure and Systems. Border security technical solutions pose an interesting domain because there are a myriad of concerns (e.g., political, economic, social and cultural) outside the technical implementation that must be deliberated and examined. In this conceptual study, unique aspects of trust, governance, information sharing, culture, and technical infrastructure are identified as the key ingredients in a cross-border collaboration effort. A bi-national organizational network appears to be an effective institutional design to develop a better understanding of the problem, as well as required policies and technologies. This approach is consistent with experiments, research, and conclusions found in the European Union.
Handoff and Route Optimization in Mobile Networks over IEEE 802.16e
Authors: Mohammed Badiea Abdulkarem , Wan Tat-Chee
Published: July 2013

To fulfill the need for on-the-move and uninterrupted internet connectivity in Mobile Networks, IETF NEMO working group was created to extend basic end-host mobility support in Mobile IPv6 (MIPv6) protocol. NEMO Basic Support Protocol (NEMO) has been standardized by this group to provide the network mobility support. However, the handover latency in NEMO is high and, the nested tunnels’ problem in the nested NEMO networks is not considered. Many schemes have been proposed to solve these problems by optimizing the handover signaling procedure, and by proposing routing optimization scheme for NEMO. Better optimized signaling procedure is proposed in this paper, and a proposed Routing Optimization scheme as a solution for the lack of the nested tunnels’ problem is proposed as well. Analytical results highlight the importance of the proposed scheme comparing to others are provided, revealing that the proposed scheme has the lowest handover latency and disruption time.
The Robustness of RM-DSR Multipath Routing Protocol with Different Network Size in MANET
Authors: Husieen Naseer Ali , Hassan Suhaidi , Ghazali Osman , Siregar Lelyzar
Published: July 2013

This paper evaluates the performance of Reliable Multipath Dynamic Source Routing Protocol (RM-DSR) protocol with different network size compared to DSR protocol. RM-DSR developed in the mobile ad-hoc network to recover from the transient failure quickly and divert the data packets into a new route before the link is disconnected. The performance of RM-DSR protocol is tested in the Network Simulator (NS-2.34) under the random way point mobility model with varying number of mobile nodes. The network size parameter is used to investigate the robustness and the efficiency of RM-DSR protocol compared to DSR protocol. The network size affects the time of the route discovery process during the route establishment and the route maintenance process which could influence the overall performance of the routing protocol. The simulation results indicate that RM-DSR outperforms DSR in terms of the packet delivery ratio, routing overhead, end-to-end delay, normalized routing load and packet drop.
Wireless Communication Technologies for Vehicular Nodes
Authors: Mohanan Vasuky , Budiarto Rahmat
Published: July 2013

In many countries, road accidents are a leading cause of death as well as being financially draining to the authorities concerned. This problem can be alleviated by having a mechanism to enable exchange of safety related messages to road users in a timely manner. This has given rise to active research in identifying the best technology. Providing comfort and smooth driving experience is also propelling the need to support vehicular communication. These groups of applications present opposing paradigms whereby safety related messages must be exchanged in real-time and characterized by short bursts of traffic and satisfying these diverse criteria are challenging for wireless communications that is the backbone of vehicular communication. Additionally, vehicular nodes sometimes move at high speeds, presenting an added dimension to the complexities surrounding vehicular communication. This article attempts to show the many myriad wireless technologies that have been tossed about as the solution. Choosing the most suitable candidate has to take into account many aspects. This article guides stakeholders such as transport policy decision makers, vehicle makers, and spectrum allocator, to enable them to make a wise and informed decision regarding the right mechanism to use to support vehicular communication.
Paris and Galt Moraines, southern Ontario: depositional elements, paleoglacial implications, and hydrogeological applications
Authors: Russell H A J , Bajc A , Sharpe D R , Cummings D I
Published: July 2013

Moraines have been mapped in Southern Ontario for nearly one hundred years (Taylor, 1913), yet their composition and depositional origin remains poorly understood. Moraines in this area have been assigned to one of two classes: i) stratified interlobate moraines
and ii) till or recessional moraines. The Paris and Galt moraines were assigned to the till or recessional moraine class (eg. Chapman & Putram, 1943). The Paris and Galt moraines are 130 km long, are up to 11 km wide, and have relief of 30 m. They evolve from two distinct ridges in the south
to a broad hummocky terrain with multiple ridges and secondary landscape elements (kettle depressions, eskers, subaerial fans, channels) northward. These geomorphic changes are mirrored by changes in geology, thickness, and stratigraphy.
Continuous cores from boreholes reveal that the Paris moraine consists of a succession of intercalated gravel and diamicton. Depending on the geographic location, a number of units can underlie the moraine, including bedrock, older till, lacustrine sediment, and glacifluvial gravel. Outcrop data
suggest northern and southern parts of the moraine are different. Within the southern mud-rich glacilacustrine basin, large sand and gravel foresets of 10 m height occur at the base of pit exposures. By contrast, horizontally stratified outwash gravel is common in northern pits. Wentworth TiIl
covers a large part of the moraine, it is massive to stratified and is locally interbedded with sand and gravel. Where overlain by the surficial gravel, its upper contact can be loaded.
The moraine strata are interpreted to have been deposited by a fluctuating, retreating ice margin with a highly variable meltwater flux both, spatially and temporally. The narrow, southern moraine ridges may represent more rapid deposition within a glacial lake basin, whereas the northern, broader
hummocky terrain is interpreted to have been deposited in a terrestrial environment. The moraine is significant hydrogeologically because the hummocky terrain may enhance recharge to bedrock and sand and gravel aquifers at depth.
Establishment of a highly efficient regeneration method from the scraped broken embryo of mature barley seed
Authors: Hua Wei , Zhu Jinghuan , Shang Yi , Wang Junmei , Jia Qiaojun , Lin Feng , Yang Jianming
Published: July 2013

Hua, W., Zhu, J., Shang, Y., Wang, J., Jia, Q., Lin, F. and Yang, J. 2013. Establishment of a highly efficient regeneration method from the scraped broken embryo of mature barley seed. Can. J. Plant Sci. 93: 1029–1035. An efficient and reproducible plant regeneration system for mature barley would represent a significant innovation for barley tissue culture and genetic transformations to optimize barley crop traits. To address this need, we used scraped broken embryos (SBEs) from dried barley seeds to establish a highly efficient regeneration system. Mature SBEs cultured in an induction medium with 2 mg L−12,4-D offered the best callus formation (92.99% induction efficiency) and no germination. Furthermore, calli arising from SBEs had the highest regeneration frequency (69.72%) in FHG medium with 1 mg L−16-benzylaminopurine. We then compared three different cultivars: Golden Promise, Zaoshu3, and Zhepi8 for callogenesis and regeneration using an established protocol. Zhepi8 had the greatest callus induction (92.78%) and regeneration (68.24%). Our innovative methods for mature barley plant reproduction will contribute to improvements in genetic barley transformation as an alternate regeneration system.
Analysis of projected drought hazards for Hungary
Authors: Bartholy J. , Pongrácz R. , Hollósi B.
Published: July 2013

Abstract. Global climate change may result in severe regional consequences affecting agricultural production potential. One of the essential climatic impacts is associated with drought conditions. Therefore, projected future changes of several drought indices are analyzed for the future period 2071–2100 (compared to 1961–1990, as a reference period) using three different global emission scenarios (A2, A1B, and B2). The monthly time series of the indices have been calculated from the simulation outputs of the regional climate model PRECIS (Providing REgional Climates for Impacts Studies) for Central/Eastern Europe with 25 km horizontal resolution accomplished by the Department of Meteorology, Eötvös Loránd University. According to the results significant drying is projected in the region, especially in summer.
Swept under the carpet: the effect of organic matter burial in global biogeochemical ocean models
Authors: Kriest I. , Oschlies A.
Published: July 2013

Abstract. Although of substantial importance for marine tracer distributions and eventually global carbon, oxygen, and nitrogen fluxes, the interaction between sinking and remineralization of organic matter, benthic fluxes and burial is not always represented consistently in global biogeochemical models. We here aim to investigate the relationships between these processes with a suite of global biogeochemical models, each simulated over millennia, and compared against observed distributions of pelagic tracers and benthic and pelagic fluxes. We concentrate on the representation of sediment-water interactions in common numerical models, and investigate their potential impact on simulated global sediment-water fluxes and nutrient and oxygen distributions. We find that model configurations with benthic burial simulate global oxygen well over a wide range of possible sinking flux parameterizations, making the model more robust with regard to uncertainties about the remineralization length scale. On a global scale, burial mostly affects oxygen in the meso- to bathypelagic zone. While all model types show an almost identical fit to observed pelagic particle flux, and the same sensitivity to particle sinking speed, comparison to observational estimates of benthic fluxes reveals a more complex pattern and may be influenced by the data distribution and methodology. Still, evaluating model results against observed pelagic and benthic fluxes of organic matter can complement model assessments based on more traditional tracers such as nutrients or oxygen. Based on a combined metric of dissolved tracers and biogeochemical fluxes, we here identify two model descriptions of burial as suitable candidates for further experiments and eventual model refinements.
ESOLIP – estimate of solid and liquid precipitation at sub-daily time resolution by combining snow height and rain gauge measurements
Authors: Mair E. , Bertoldi G. , Leitinger G. , Della Chiesa S. , Niedrist G. , Tappeiner U.
Published: July 2013

Abstract. Measuring precipitation in mountain areas is a demanding task, but essential for hydrological and environmental themes. Especially in small Alpine catchments with short hydrological response, precipitation data with high temporal resolution are required for a better understanding of the hydrological cycle. Since most climate/meteorological stations are situated at the easily accessible bottom of valleys, and the few heated rain gauges installed at higher elevation sites are problematic in winter conditions, an accurate quantification of winter (snow) precipitation at high elevations remains difficult. However, there are an increasing number of micro-meteorological stations and snow height sensors at high elevation locations in Alpine catchments. To benefit from data of such stations, an improved approach to estimate solid and liquid precipitation (ESOLIP) is proposed. ESOLIP allows gathering hourly precipitation data throughout the year by using unheated rain gauge data, careful filtering of snow height sensors as well as standard meteorological data (air temperature, relative humidity, global shortwave radiation, wind speed). ESOLIP was validated at a well-equipped test site in Stubai Valley (Tyrol, Austria), comparing results to winter precipitation measured with a snow pillow and a heated rain gauge. The snow height filtering routine and indicators for possible precipitation were tested at a field site in Matsch Valley (South Tyrol, Italy). Results show a good match with measured data because variable snow density is taken into account, which is important when working with freshly fallen snow. Furthermore, the results show the need for accurate filtering of the noise of the snow height signal and they confirm the unreliability of heated rain gauges for estimating winter precipitation. The described improved precipitation estimate ESOLIP at sub-daily time resolution is helpful for precipitation analysis and for several hydrological applications like monitoring systems and rainfall-runoff models.
Application of singularity theory and logistic regression model for tungsten polymetallic potential mapping
Authors: Liu Y. , Xia Q. , Cheng Q. , Wang X.
Published: July 2013

Abstract. Geo-anomalies with complex structures in the earth's crust may be defined as preferable hydrothermal ore-forming targets. The separation and explanation of anomaly from geological background have a profound influence on the analysis of geological evolution and the ore-forming process. Usually one of the key steps to identify favorable exploration targets is to determine the threshold to separate anomaly from geological background. In this paper, the singularity theory and concentration–area (C–A) fractal method was applied in determination of the threshold of geo-anomalies. According to the thresholds, four singular maps can be each divided into two segments. Each of them is correlated to the anomaly and background of the geological objects (e.g., faults, fault intersections and contacts), which reveals that the various geo-anomalies can be characterized by the singularities. The results indicate that the local singularity method can be used to identify the weak anomalies in a low background. Logistic regression model was used to combine geo-singularity maps for mineral potential mapping, which provides a useful input for further mineral exploration in the Nanling tungsten polymetallic belt, South China.
Microstructure measurements and estimates of entrainment in the Denmark Strait overflow plume
Authors: Paka V. , Zhurbas V. , Rudels B. , Quadfasel D. , Korzh A. , Delisi D.
Published: July 2013

Abstract. To examine processes controlling the entrainment of ambient water into the Denmark Strait overflow (DSO) plume/gravity current, measurements of turbulent dissipation rate were carried out by a quasi-free-falling (tethered) microstructure profiler (MSP). The MSP was specifically designed to collect data on dissipation-scale turbulence and fine thermohaline stratification in an ocean layer to depths of 3500 m. The task was to perform microstructure measurements in the DSO plume in the lower 300 m depth interval including the bottom mixed layer and the interfacial layer below the non-turbulent ambient water. The MSP was attached to a Rosette water sampler rack equipped with a SeaBird CTDO and an RD Instruments Lowered Acoustic Doppler Current Profiler (LADCP). At a chosen depth, the MSP was remotely released from the rack to perform measurements in a quasi-free-falling mode. Using the measured vertical profiles of dissipation, the entrainment rate as well as the bottom and interfacial stresses were estimated in the DSO plume at a location 200 km downstream of the sill at depths up to 1771 m. Dissipation-derived estimates of entrainment were found to be much smaller than bulk estimates of entrainment calculated from the downstream change of the mean properties in the plume, suggesting the lateral stirring due to meso-scale eddies rather than diapycnal mixing as the main contributor to entrainment. Dissipation-derived bottom stress estimates are argued to be roughly one-third the magnitude of those from log velocity profiles. In the interfacial layer, the Ozmidov scale calculated from turbulence dissipation rate and buoyancy frequency was found to be linearly proportional to the overturning scale extracted from conventional CTD data (the Thorpe scale), with a proportionality constant of 0.76, and a correlation coefficient of 0.77.
Non‐physician clinician provided HIV treatment results in equivalent outcomes as physician‐provided care: a meta‐analysis
Authors: Emdin Connor A , Chong Nicholas J , Millson Peggy E
Published: July 2013

Introduction

A severe healthcare worker shortage in sub‐Saharan Africa is inhibiting the expansion of HIV treatment. Task shifting, the transfer of antiretroviral therapy (ART) management and initiation from doctors to nurses and other non‐physician clinicians, has been proposed to address this problem. However, many health officials remain wary about implementing task shifting policies due to concerns that non‐physicians will provide care inferior to physicians. To determine if non‐physician‐provided HIV care does result in equivalent outcomes to physician‐provided care, a meta‐analysis was performed.

Methods

Online databases were searched using a predefined strategy. The results for four primary outcomes were combined using a random effects model with sub‐groups of non‐physician‐managed ART and ‐initiated ART. TB diagnosis rates, adherence, weight gain and patient satisfaction were summarized qualitatively.

Results

Mortality (N=59,666) had similar outcomes for non‐physicians and physicians, with a hazard ratio of 1.05 (CI: 0.88–1.26). The increase in CD4 levels at one year, as a difference in means of 2.3 (N=17,142, CI: −12.7–17.3), and viral failure at one year, as a risk ratio of 0.89 (N=10,344, CI: 0.65–1.23), were similar for physicians and non‐physicians. Interestingly, loss to follow‐up (LTFU) (N=53,435) was reduced for non‐physicians with a hazard ratio of 0.72 (CI: 0.56–0.94). TB diagnosis rates, adherence and weight gain were similar for non‐physicians and physicians. Patient satisfaction appeared higher for non‐physicians in qualitative components of studies and was attributed to non‐physicians spending more time with patients as well as providing more holistic care.

Conclusions

Non‐physician‐provided HIV care results in equivalent outcomes to care provided by physicians and may result in decreased LTFU rates.
Size‐Dependent Charge Transfer in Blends of PbS Quantum Dots with a Low‐Gap Silicon‐Bridged Copolymer
Authors: Itskos Grigorios , Papagiorgis Paris , Tsokkou Demetra , Othonos Andreas , Hermerschmidt Felix , Economopoulos Solon P. , Yarema Maksym , Heiss Wolfgang , Choulis Stelios
Published: July 2013

The photophysics of bulk heterojunctions of a high‐performance, low‐gap silicon‐bridged dithiophene polymer with oleic acid capped PbS quantum dots (QDs) are studied to assess the material potential for light harvesting in the visible‐ and IR‐light ranges. By employing a wide range of nanocrystal sizes, systematic dependences of electron and hole transfer on quantum‐dot size are established for the first time on a low‐gap polymer–dot system. The studied system exhibits type II band offsets for dot sizes up to ca. 4 nm, whch allow fast hole transfer from the quantum dots to the polymer that competes favorably with the intrinsic QD recombination. Electron transfer from the polymer is also observed although it is less competitive with the fast polymer exciton recombination for most QD sizes studied. The incorporation of a fullerene derivative provides efficient electron‐quenching sites that improve interfacial polymer‐exciton dissociation in ternary polymer–fullerene–QD blends. The study indicates that programmable band offsets that allow both electron and hole extraction can be produced for efficient light harvesting based on this low‐gap polymer‐PbS QD composite.
Evaluating the frequency and characteristics of seizures in 142 Japanese patients with prader–willi syndrome
Authors: Takeshita Eri , Murakami Nobuyuki , Sakuta Ryoichi , Nagai Toshiro
Published: July 2013

Prader–Willi syndrome (PWS) has not been widely regarded as a disorder with a risk factor for seizures. We retrospectively investigated the frequency and characteristics of seizures and examined genotype–phenotype correlations with respect to seizures in PWS. We analyzed 142 patients with PWS and identified 31 (22%) with seizures. The most common seizure type was febrile convulsion (12%, 17/142). Epilepsy occurred in 6% of the patients in our cohort (9/142). The frequencies of febrile seizure and epilepsy in PWS were higher than those in the general population. Our study suggested that the frequency of seizures was not associated with genotypes of PWS (P = 0.35). In our study patients with PWS, 68% of the patients with seizures experienced initial episodes before they were 2 years old, and the seizures were relatively easier to manage. © 2013 Wiley Periodicals, Inc.
Camurati–engelmann disease with obesity in a newly identified family carrying a missense p.Arg156Cys mutation in the TGFB1 gene
Authors: Collet Corinne , Laplanche Jean‐Louis , de Vernejoul Marie‐Christine
Published: July 2013

We report on a family affected by Camurati–Engelmann disease, characterized by radiological signs limited to the tibia, and associated with overweight or obesity, which is not a known feature of this disorder. The affected patients were heterozygous for a c.466C > T mutation (which predicts p.Arg156Cys) in the latency associated protein (LAP)‐coding domain of the TGFB1 gene. This mutation had previously been reported once in another family with a similar, atypical phenotype, which suggests a possible phenotype/genotype relationship. © 2013 Wiley Periodicals, Inc.
ZnS:Cr and ZnSe:Cr thin‐film waveguide structures as electrically pumped laser media with an impact excitation mechanism
Authors: Vlasenko Nataliya A. , Oleksenko Pavel F. , Mukhlyo Miroslav A. , Denisova Zinaida L. , Veligura Ludmila I.
Published: July 2013

ZnS:Cr and ZnSe:Cr are the focus of studies as media for broadly tunable optically pumped lasers operating in the near‐ and mid‐IR regions. It is of great interest to obtain such lasers electrically pumped. The effective electrical excitation of Cr2+ ions was demonstrated only in the case of the impact mechanism for thin‐film structures with insulator layers between an electroluminescent film and electrodes, which prevent avalanche breakdown at high electric field (≥ 1 MV/cm). To obtain lasing, the waveguide electroluminescent structures were used. For the first time, the stimulated emission and the laser oscillation were demonstrated in the ZnS:Cr waveguide structures. Although the lasing is unstable as yet, these results lay the foundations of a new direction in laser physics aimed at creation of electrically pumped lasers by dint of impact excitation. Published results concerning various aspects of ZnS:Cr and ZnSe:Cr thin films and waveguide structures as promising electrically pumped laser media are reviewed. The causes of the instability of the laser oscillation and means of improving their characteristics are also considered.
Curing kinetics of diglycidyl ether of bisphenol‐A (n = 0) using an iron‐containing porphyrin as cross‐linking agent
Authors: Vázquez Eva C. , Fraga Francisco , Martínez‐Ageitos J. M. , Tato José Vázquez
Published: July 2013

The curing reaction of a system consisting of a diglycidyl ether of bisphenol‐A (n = 0) and hemin (a protoporphyrin IX containing an iron ion and an additional chloride ligand) was studied with a differential scanning calorimeter. A maximum value of −488.3 ± 8.4 J g−1 was obtained for the enthalpy of the reaction. The kinetics of the process was studied by the isothermal method, observing that it obeys to Kamal's model, with an overall reaction order equal to 3. From the dependence of the kinetic constant with temperature, the activation energy, activation enthalpy, and activation entropy were determined. The ratio of the kinetic constants associated to the autocatalytic and nth order terms of the reaction rate, together with the thermodynamic activation parameters suggest a trend to the autocatalytic path mechanism with increasing temperatures. This study demonstrates that macrocycles can be used as cross‐linking agents for curing epoxy resins and that when metallomacrocycles are used, metal ions can be introduced into the network structure. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3972–3978, 2013
Adolescents' information‐creating behavior embedded in digital Media practice using scratch
Authors: Koh Kyungwon
Published: July 2013

This study explores the ways adolescents create information collaboratively in the digital environment. In spite of the current widespread practice of information creation by young people, little research exists to illuminate how youth are engaged in creative information behavior or how they make participatory contributions to the changing information world. The purposefully selected sample includes teenagers who actively produce and share information projects, such as online school magazines, an information‐sharing website in Wiki, and a digital media library, using Scratch—a graphical programming language developed by MIT Media Lab. Qualitative data were collected through group and individual interviews informed by Dervin's Sense‐Making Methodology. The data analysis technique included directed qualitative content analysis with Atlas.ti. Findings reveal the process of information creation, including content development, organization, and presentation of information, as well as noticeable patterns by youth such as visualizing, remixing, tinkering, and gaining a sense of empowerment. This study extends our knowledge of the creative aspects of information behavior.
An Engineered Calmodulin‐Based Allosteric Switch for Peptide Biosensing
Authors: Meister Glenna E. , Joshi Neel S.
Published: July 2013

This work describes the development of a new platform for allosteric protein engineering that takes advantage of the ability of calmodulin to change conformation upon binding to peptide and protein ligands. The switch we have developed consists of a fusion protein in which calmodulin is genetically inserted into the sequence of TEM1 β‐lactamase. In this approach, calmodulin acts as the input domain, whose ligand‐dependent conformational changes control the activity of the β‐lactamase output domain. The new allosteric enzyme exhibits up to 120 times higher catalytic activity in the activated (peptide bound) state compared to the inactive (no peptide bound) state in vitro. Activation of the enzyme is ligand‐dependent—peptides with higher affinities for wild‐type calmodulin exhibit increased switch activity. Calmodulin's ability to “turn on” the activity of β‐lactamase makes this a potentially valuable scaffold for the directed evolution of highly specific biosensors for detecting toxins and other clinically relevant biomarkers.
Delivery of a bioresorbable vascular scaffold to complex lesions
Authors: Meincke Felix , Kuck Karl‐Heinz , Bergmann Martin W.
Published: July 2013

The use of bioresorbable vascular scaffolds (BVS) in percutaneous coronary interventions holds great promise and the Absorb® BVS is increasingly used in clinical practice outside of controlled studies. However, questions have been raised concerning the delivery of the scaffold to complex lesions. We describe a case of successful delivery and implantation of two overlapping Absorb® BVS to a complex lesion in the left anterior descending artery. The crossing of the lesions was uneventful and after implantation a good acute result could be documented. A follow‐up angiogram after 3 months proofed a stable midterm result. We thereby demonstrate the feasibility of delivering Absorb® BVS to more complex lesions than practiced so far in the setting of clinical trials. © 2013 Wiley Periodicals, Inc.
Hydrodynamic study of a mixture of West Indian Cherry Residue and Soybean Grains in a spouted bed
Authors: Bortolotti Carolina T. , Santos Kassia G. , Francisquetti Mariele C. C. , Duarte Claudio R. , Barrozo Marcos A. S.
Published: July 2013

West Indian cherry, widely known as acerola in Latin America, is a fruit rich in vitamin C and other bioactive compounds. In Brazil, the largest producer of acerola in the world, the processing of this fruit results in large amounts of waste or residues. A method that allows these residues to be reused is drying. However, acerola residue has low flowability in spouted beds due to its low density and high moisture content. Therefore, in this study, soybean was used as an auxiliary material to maintain the stability of the fluid dynamics and the characteristics of the food end product. Because this process involves a mixture of solids of different sizes, shapes and densities, particle segregation may occur. This article reports on a study of the fluid dynamics of the mixture of acerola residue and soybean in a spouted bed, operating with different mass fractions of residue and different static bed heights. Particle segregation was analysed, allowing for the quantification of the effect of the initial concentration of acerola residue on the degree of miscibility. The content of phenolic compounds, flavonoids and ascorbic acid, as well as the moisture and mixture indices at different drying times, were also quantified.
Assessing Solvation Effects on Chemical Reactions with Globally Optimized Solvent Clusters
Authors: Li Yan , Hartke Bernd
Published: July 2013

We have examined the influence of water solvent on the Menshutkin reaction of methyl chloride with ammonia by performing static, quantum chemical calculations. We have employed large, explicit, and globally structure‐optimized water clusters around the reaction center, in a mixed explicit/implicit solvent model. This approach deliberately deviates from attempts to capture the most likely solvent‐molecule distribution around a reaction center. Instead, it explores extremes on the scale of rearrangement speed in terms of the surrounding solvent cluster, relative to the reaction progress itself. A comparison to traditional theoretical and experimental results enables us to quantify the energy penalty that is induced by the inability of the water cluster to instantaneously and completely follow the reaction progress. In addition, the influence of water clusters on the reaction energy profile can be much larger than merely changing it somewhat. Certain clusters can completely annihilate the sizeable activation barrier of 23.5 kcal mol−1.
Nitrogen‐Doped Pt/C Electrocatalysts with Enhanced Activity and Stability toward the Oxygen Reduction Reaction
Authors: Choi Sang‐Il , Lee Su‐Un , Choi Ran , Park Joon T. , Han Sang Woo
Published: July 2013

Recently, nitrogen‐doped carbon materials have proved to be effective catalytic platforms for the oxygen reduction reaction (ORR). Despite the recent synthetic advances for the preparation of nitrogen‐incorporated carbon materials, the low‐temperature and water‐based synthesis of nitrogen‐doped carbon materials has rarely been explored due to the difficulties in nitrogen‐doping under such mild conditions. Here, nitrogen‐doped Pt/C (Pt/NC) catalysts are prepared using a facile, low‐temperature, aqueous‐phase method. Hydrazine treatment of a Pt/C catalyst successfully yields Pt/NC with controlled nitrogen content. The as‐prepared Pt/NC catalysts exhibit enhanced electrocatalytic activity and stability toward ORR in comparison to nitrogen‐free Pt/C, and their ORR activities are highly dependent on the level of nitrogen‐doping. The Pt/NC catalyst containing 2.0 at % nitrogen results in the largest improvement of ORR activity.
Effect of acarbose to delay progression of carotid intima–media thickness in early diabetes
Authors: Patel Y. R. , Kirkman M. S. , Considine R. V. , Hannon T. S. , Mather K. J.
Published: July 2013

Background

The anti‐diabetic agent acarbose reduces postprandial glucose excursions. We have evaluated the effect of randomized treatment with acarbose on the progression of carotid intima–media thickness (IMT) in early diabetes.

Methods

The Early Diabetes Intervention Program was a randomized trial of acarbose versus placebo in 219 participants with early diabetes characterized by glucose values over 11.1 mmol/L 2 h after a 75 g oral glucose load and a mean HbA1c of 6.3%. IMT was measured at baseline and yearly. Follow‐up was discontinued if participants progressed to the study glucose endpoints; IMT readings were available for a median of 2 years, with 72 subjects followed for 5 years.

Results

Progressive increases in IMT were seen in both treatment groups, but progression was reduced in participants randomized to acarbose (p = 0.047). In age, sex and smoking‐adjusted analyses, IMT progression was associated with greater fasting and oral glucose tolerance test‐excursion glucose, fasting insulin, cholesterol and glycated low‐density lipoprotein concentrations. IMT progression was reduced with study‐related changes in weight, insulin and non‐esterified fatty acids; these features were more strongly associated with reduced IMT progression than acarbose treatment. Despite strong associations of baseline glycemia with IMT progression, study‐related changes in glucose were not important determinants of IMT progression.

Conclusions

Acarbose can delay progression of carotid intima–media thickness in early diabetes defined by an oral glucose tolerance test. Glucose, weight, insulin and lipids contributed to risk of progression but reductions in glycemia were not major determinants of reduced rate of IMT progression. Vascular benefits of acarbose may be independent of its glycemic effects. Copyright © 2013 John Wiley & Sons, Ltd.
Spatial characteristics of surface water and groundwater using water stable isotope in the Tarim River Basin, northwestern China
Authors: Zhang Yucui , Shen Yanjun , Chen Yaning , Wang Yun
Published: July 2013

Water resources management of the Tarim River Basin in China is hampered because it is poorly gauged, leading to inadequate understanding of the components of the hydrological cycle. This is an important problem to both ecology and society in this arid basin. In this paper, we attempt to investigate the isotopic characteristics of the surface water and groundwater in the Tarim River Basin and estimate the water evaporation loss from lakes. By measuring the water stable isotope composition and by using a mass balance model, we analyzed the spatial characteristics of the isotope composition, and isotopic water lines for surface water and groundwater were determined. Phreatic water evaporation was verified on the basis of the isotope composition results. The spatial variability of the Aksu River exhibited a ‘toward lighter–heavier’ change along the main stream for both δ18O and δD, and the distributions could be described by a cubic equation. The isotope composition of the evaporation vapour (δE) of the Aksu River decreased with distance. No regular trend was observed for the Tarim River between the isotope composition and distance, whereas δE appeared to exhibit the same characteristics. This study is the first to use the isotopic method in the evaporation research for Bosten Lake. The water fraction lost [evaporation (E)/inflow (I)] in October was 0·25, which suggests that 0·68 × 108 m3 input water was lost to evaporation. Copyright © 2013 John Wiley & Sons, Ltd.