Stand up: comparison of two electrical screed levelling machines to reduce the work demands for the knees and low back among floor layers

Electrical screed levelling machines are developed to reduce kneeling and trunk flexion of sand–cement-bound screed floor layers. An observational intervention study among 10 floor layers was performed to assess the differences between a self-propelled and a manually moved machine. The outcome measures were work demands, production time, perceived load, discomfort and applicability. Compared to the self-propelled machine, the duration of kneeling (?13 min; p = 0.003) and trunk flexion (?12 min; p < 0.001) was shorter using the manually moved machine, and the duration of pushing and pulling increased (?39 min; p < 0.001). No significant or relevant differences were found for production time, perceived load and discomfort. Nine out of ten floor layers found the manually moved machine applicable and three out of ten found the self-propelled machine applicable. When compared with the traditional manner of floor laying, both electrical machines reduced the exposure towards kneeling and trunk flexion.

Practitioner Summary: Electrical machines may help to reduce high physical work demands on floor layers. A manually moved machine is better applicable for the installation of screed floors in residences with smaller floor areas. A self-propelled machine is better applicable on large floor areas with a minimum width of 4 m.     

User requirements of mobile technology: results from a content analysis of user reviews

Advanced mobile technology continues to shape professional environments. Smart cell phones, pocket computers and laptop computers reduce the need of users to remain close to a wired information system infrastructure and allow for task performance in many different contexts. Among the consequences are changes in technology requirements, such as the need to limit weight and size of the devices. In the current paper, we focus on the factors that users find important in mobile devices. Based on a content analysis of online user reviews that was followed by structural equation modeling, we found four factors to be significantly related with overall user evaluation, namely functionality, portability, performance, and usability. Besides the practical relevance for technology developers and managers, our research results contribute to the discussion about the extent to which previously established theories of technology adoption and use are applicable to mobile technology. We also discuss the methodological suitability of online user reviews for the assessment of user requirements, and the complementarity of automated and non-automated forms of content analysis.     

Sympathy or strategy: social capital drivers for collaborative contributions to the IS community

Despite growing interest in delineating the social identity of Information Systems (IS) research and the network structures of its scholarly community, little is known about how the IS community network is shaped by individual conceptions and what motivates IS researchers to engage in research collaboration. Using an exploratory theoretical framework that is based on three dimensions of social capital theory, we examined 32 years of scientific co-authorship in an international IS researcher community. We formulated propositions to empirically examine the multi-level relationships between personal drivers and the resulting complex network organization of the IS community. Our propositions are refined with qualitative interviews and tested using a survey. This process revealed a collaborative research culture with several individual dispositions, including a strategic structural focus, a cognitive focus and a relational focus. These exist among actors displaying a range of differing behaviours such as active engagement and passive serendipity. Our study indicates individual differences at the conception stage of engaging in academic collaboration impact on the resulting network-level configuration. We identified that regional preference, maturity life cycles and lack of small-world properties highlight the important role of senior members as structural backbones and brokers within the IS community.     

Can the interactive whiteboard support young children’s collaborative communication and thinking in classroom science activities?

Interactive whiteboards (IWBs) have been widely introduced to English primary schools (5–11 years) in the last decade and this has generated much research interest. In the past, research has focused on IWB-use in teacher-led sessions, attending particularly to the nature of teacher-pupil interaction at the IWB and the apparent motivational advantages for children. In contrast, this study focuses on children’s communication and thinking during their semi-autonomous use of the IWB during collaborative groupwork in primary school science lessons, aiming in part to see if the IWB is suited to this type of use. Over the course of one school year, twelve primary teachers of Years 4 and 5 (8–10 years) took part in a professional development and research programme which involved them in devising a sequence of three science lessons incorporating small-group activity at the IWB. The functionality of the IWB is analysed here as means for supporting the children’s joint communication and thinking, using embedded cues and the availability of certain features in the IWB technology. Our observational analysis of two examples of children’s collaborative activity in different classrooms, together with subsequent group interviews, suggests that the IWB can make some identifiable contributions to children’s productive communication and thinking. However the IWB is not seen to be an entirely distinctive or pedagogically transformative learning resource in the primary classroom. In our developing conceptual framework, the children’s knowledge building is closely related to their active engagement in using IWB affordances and their productive dialogue, essentially supported by the teacher’s scaffolding strategies, the establishment and use of “talk rules” in conversation, and the opportunities and constraints applying in classroom participation structures. These conditions help the children to deal with interconnected social, cognitive, and technical problems arising over time. Certain aspects of this form of computer-supported collaborative learning (CSCL) are discussed. These relate to the integration of the IWB with other classroom learning systems and resources, and to the nature of progression in children’s activity and learning with this new type of highly integrated system of CSCL.     

Prevention of relapse/recurrence in major depression by mindfulness-based cognitive therapy.

This study evaluated mindfulness-based cognitive therapy (MBCT), a group intervention designed to train recovered recurrently depressed patients to disengage from dysphoria-activated depressogenic thinking that may mediate relapse/recurrence. Recovered recurrently depressed patients (n?=?145) were randomized to continue with treatment as usual or, in addition, to receive MBCT. Relapse/recurrence to major depression was assessed over a 60-week study period. For patients with 3 or more previous episodes of depression (77% of the sample), MBCT significantly reduced risk of relapse/recurrence. For patients with only 2 previous episodes, MBCT did not reduce relapse/recurrence. MBCT offers a promising cost-efficient psychological approach to preventing relapse/recurrence in recovered recurrently depressed patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term and long-term consequences of achievement goals: Predicting interest and performance over time.

Why do some students excel in their college classes and develop interest in an academic discipline? The authors examined both the short-term and long-term consequences of students' achievement goals in an introductory psychology course. Mastery goals positively predicted subsequent interest in the course, but not course grades. Performance goals positively predicted grades, but not interest. Three semesters later, the authors obtained measures of continued interest in the discipline and long-term performance. Mastery goals predicted subsequent enrollment in psychology courses, whereas performance goals predicted long-term academic performance. These positive and complementary effects of mastery and performance goals on different measures of academic success are consistent with a multiple-goals perspective in which both goals can have beneficial consequences in college education. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thin-Layer Chromatography Assessing Feeding Stimulation by Labial Gland Secretion Compared to Synthetic Chemicals in the Subterranean Termite Reticulitermes santonensis

The labial gland of the French subterranean termite Reticulitermes santonensis De Feytaud contains a polar, heat-resistent, and persistent chemical signal that is released onto the food during food exploitation and stimulates feeding in nestmates. Separation of the labial gland secretion by thin-layer chromatography on cellulose plates revealed that the secretion contains components with reducing and amino groups. In feeding bioassays conducted on the cellulose plate after TLC, termites preferred the area between Rf 0.46 and 0.88 (biologically active zone) for feeding, indicating the location of the feeding-stimulating signal. Thirty-five synthetic chemicals with similar chemical properties as the feeding-stimulating signal were analyzed with TLC. None of them covered the biologically active zone. Therefore, all chemical classes tested, such as sugars, amino acids, and salts, are unlikely as possible sources for the signal structure. In feeding choice tests with synthetic chemicals, termites showed clear feeding preference only for sugarlike components with physiologically excessive concentrations of 10 mmol and 100 mmol. Amino acids induced only light feeding preference. The intensity of feeding stimulation by the natural signal from the labial gland as compared to synthetic phagostimulants is discussed.     

Superhierarchical Inorganic/Organic Nanocomposites Exhibiting Simultaneous Ultrahigh Dielectric Energy Density and High Efficiency

Inorganic/organic dielectric nanocomposites have been extensively explored for energy storage applications for their ease of processing, flexibility, and low cost. However, achieving simultaneous high energy density and high efficiency under practically workable electric fields has been a long-standing challenge. Guided by first-principles calculations of interface properties and phase-field simulations of the dynamic dielectric breakdown process, superhierarchical nanocomposites of ferroelectric perovskites, layered aluminosilicate nanosheets, and an organic polymer matrix are designed and simultaneous high energy density of 20 J cm⁻³ and high efficiency of 84% at a low electric field of 510 MV m⁻¹ are achieved. This is the highest energy density of all the state-of-the-art dielectric polymer nanocomposites with energy efficiency > 80% at a low electric field of <600 MV m⁻¹. Strong atomic hybridization, large ionic displacement, the enhanced breakdown strength through forming charge-blocking layers, and the superhierarchical microstructure with gradient interfaces are responsible for the high performances. This superhierarchical structuring modulation strategy is generally applicable to composites for different functionalities and applications.     

Materials Informatics Reveals Unexplored Structure Space in Cuprate Superconductors

High-temperature superconducting cuprates have the potential to be transformative in a wide range of energy applications. In this work, the corpus of historical data about cuprates is analyzed using materials informatics, re-examining how their structures are related to their critical temperatures (Tc). The available data is highly clustered and no single database contains all the features of interest to properly examine trends. To work around these issues a linear calibration approach that allows the utilization of multiple data sources is employed, combining fine resolution data for which the Tc is unknown with coarse resolution data where it is known. The hybrid data set constructed enables the exploration of the trends in Tc with the apical and in-plane copper–oxygen distances. It is shown that large regions of the materials space have yet to be explored. Novel experiments relying on the nano-engineering of the crystal structure may enable the exploration of such new regions. Based on the trends identified it is proposed that single layer Bi-based cuprates are good candidate systems for such experiments.     

Food Exploitation in Termites: Indication for a General Feeding-Stimulating Signal in Labial Gland Secretion of Isoptera

The paired labial glands are located in all termite species in the thorax. During food exploitation workers of the French termite Reticulitermes santonensis and the African termite Schedorhinotermes lamanianus release the secretion of their labial glands directly onto the food. The secretion carries a water-soluble, heat-resistant, nonvolatile signal that stimulates gnawing and feeding and leads to aggregations of feeding workers. In a feeding bioassay, extracts of the labial glands of 11 termite species from five families all proved to have this feeding-stimulating effect both on R. santonensis and S. lamanianus. The heat resistance of the feeding-stimulating signal also could be shown for selected species from all termite families tested. A combined thin layer chromatography–feeding bioassay on cellulose TLC plates showed that after chromatography of labial gland secretion, the feeding-stimulating signal is located in all 11 species in the same area from R_f 0.46 to 0.88. An extract of labial glands of cockroaches stimulated feeding in R. santonensis and S. lamanianus as well, but was not active after heat treatment and after TLC. This points towards a general feeding-stimulating signal having evolved only in the labial gland secretion of termites.