Exploring the potential of blended learning to promote retention and achievement in higher education professional study programs

In this paper, we present a blended learning model designed for a university professional study program attended by full-time professional workers, i.e. in-service teachers studying in the field of School Administration. The model integrates four main instructional strategies at the program level: mentoring; participation in an online community of professional learning and practice; collaborative concept-mapping with an object-typed knowledge modeling software, and face-to-face seminars in a work setting. Based on interview and observation data collected during two successive small-scale experimentations of the model, we explored potential factors that could have had an impact on students’ academic retention and achievement. Four types of factors were identified: personal, professional, institutional and pedagogical. We found that pedagogical and professional factors, which are insufficiently considered in theoretical models of student retention, are of primary concern for students who work full-time as professionals. A blended learning model designed at the program level and strongly “situated” in the professional practice of the students is a promising avenue to adjust to their career constraints and aspirations and, thus, promoting their academic retention and achievement

Insights about the Surface of Colloidal Nanoclusters from Their Vibrational and Thermodynamic Properties

We use first principles density functional theory to study the vibrational properties of colloidal quantum dots with up to 1000 atoms. This represents a size regime where the vibrations are molecular but are reminiscent of bulk phonons. We describe how these vibration types coexist and interact. Some counterintuitive results, such as blue shifts with increasing passivant mass, are highlighted. We compare the vibrational properties of zinc-blende and wurtzite CdSe nanoclusters, and find significant differences for the “optical” modes that we attribute to the intrinsic anisotropy of the wurtzite structure. We suggest studying the low temperature specific heat to unveil the otherwise hard to access surface properties

Insights about the Surface of Colloidal Nanoclusters from Their Vibrational and Thermodynamic Properties

We use first principles density functional theory to study the vibrational properties of colloidal quantum dots with up to 1000 atoms. This represents a size regime where the vibrations are molecular but are reminiscent of bulk phonons. We describe how these vibration types coexist and interact. Some counterintuitive results, such as blue shifts with increasing passivant mass, are highlighted. We compare the vibrational properties of zinc-blende and wurtzite CdSe nanoclusters, and find significant differences for the “optical” modes that we attribute to the intrinsic anisotropy of the wurtzite structure. We suggest studying the low temperature specific heat to unveil the otherwise hard to access surface properties

Cotton aphid population dynamics.

<p>Mean numbers (±SEM) of <i>A. gossypii</i> per plot in the various natural enemy exclusion treatments from early August to end of September in Bt cotton in Ezhou (China).</p

Intrinsically Conductive Polymer Fibers from Thermoplastic <i>trans</i>-1,4-Polyisoprene

Herein, we report a new strategy to prepare conductive polymer fibers to overcome the insurmountable weakness of current conductive polymer fibers. First, special thermoplastic polymers are processed into polymer fibers using a conventional melt-spinning process, and then the nonconductive polymer fibers are converted into intrinsically conductive polymer fibers. Using this new strategy, intrinsically conductive polymer fibers have been prepared by melt spinning low-cost thermoplastic <i>trans</i>-1,4-polyisoprene and doping with iodine, which can be as fine as 0.01 mm, and the resistivity can be as low as 10^–2 Ω m. Moreover, it has been found that drawing can improve the orientation of <i>trans</i>-1,4-polyisoprene crystals in the fibers and, thus, the conductivity of the conductive polymer fibers. Therefore, conductive fibers with excellent conductivities can be prepared by large drawing ratios before doping. Such conductive polymer fibers with low cost could be used in textile, clothing, packing, and other fields, which would benefit both industry and daily life. The newly developed method also allows one to produce conductive polymers of any shape besides fibers for antistatic or conductive applications

Dominant arthropods, per guild, found during the surveys.

<p>Total counts of dominant arthropods per guild in the experimental blocks during the field survey from August 4^th to September 30^th, 2011, in Ezhou (China).</p>a<p>mainly <i>Propylaea japonica</i> Thunberg (292, 65.03%), <i>Harmonia axyridis</i> Pallas (90, 20.04%) and <i>Coccinella septempunctata</i> Linnaeus (67, 14.92%).</p>b<p>mainly <i>Erigonidium graminicolum</i> Sundevall.</p>c<p>mainly from Miridae, Nabidae and Anthocoridae families.</p><p>Dominant arthropods, per guild, found during the surveys.</p

Population dynamics of other natural enemies.

<p>Mean numbers (±SEM) of other natural enemies per plot in the various natural enemy exclusion treatments from early August to end of September in Bt cotton in Ezhou (China).</p

Design of the field study.

<p>(<b>A</b>) The four different cage treatments, i.e. natural enemy exclusion degree, in the field study; Exclusion cages: prevented natural enemy (predators and aphid parasitoids) movement, Restriction cage: prevented predator movement but allowed aphid parasitoids to colonize the plants, Sham cage and No cage: allowed free access to the plants for all natural enemies. (<b>B</b>) Within- and among block design: the distance among treatments within a block was 3 m, and among blocks was 10 m. The experimental cotton field was 70 m×30 m.</p

Population dynamics of coccinellid predators.

<p>Mean numbers (±SEM) of (<b>A</b>) all Coccinellids and (<b>B</b>) <i>P. japonica</i> per plot in the various natural enemy exclusion treatments from early August to end of September in Bt cotton in Ezhou (China).</p

Population dynamics of aphid parasitoids.

<p>Mean numbers (±SEM) of Aphidiine per plot in the various natural enemy exclusion treatments from early August to end of September in Bt cotton in Ezhou (China).</p