The Effects of Flow on Learning Outcomes in an Online Information Management Cou

As online courses and programs expand in business schools, it becomes increasingly important to understand the link between students\u27 experiences in these courses and learning outcomes. The study reported here investigates the relationship between students\u27 experiences of flow, a psychological state generally associated with improved task performance, and learning outcomes in an online information management course taught in an MBA program. Four learning outcomes (objective learning performance, perceived learning of the subject matter, perceived skill development, and student satisfaction) are predicted to be affected by an overall flow score, four dimensions of flow, and three characteristics of flow activities. Support is found for a relationship between flow and students\u27 perceived learning of the subject matter, students\u27 perceived skill development, and student satisfaction. The findings of the study have implications for the design and instruction of online courses offered in business schools

Reef Sediments Can Act As a Stony Coral Tissue Loss Disease Vector

Stony coral tissue loss disease (SCTLD) was first observed in 2014 near Virginia Key in Miami-Dade County, Florida. Field sampling, lab experiments, and modeling approaches have suggested that reef sediments may play a role in SCTLD transmission, though a positive link has not been tested experimentally. We conducted an ex situ transmission assay using a statistically-independent disease apparatus to test whether reef sediments can transmit SCTLD in the absence of direct contact between diseased and healthy coral tissue. We evaluated two methods of sediment inoculation: batch inoculation of sediments collected from southeast Florida using whole colonies of diseased Montastraea cavernosa, and individual inoculations of sediments following independent, secondary infections of similar to 5 cm(2) coral fragments. Healthy fragments of the coral species Orbicella faveolata and M. cavernosa were exposed to these diseased sediment treatments, as well as direct disease contact and healthy sediment controls. SCTLD transmission was observed for both batch and individual diseased sediment inoculation treatments, albeit with lower proportions of infected individuals as compared to disease contact controls. The time to onset of lesions was significantly different between species and among disease treatments, with the most striking infections occurring in the individual diseased sediment treatment in under 24 h. Following infection, tissue samples were confirmed for the presence of SCTLD signs via histological examination, and sediment subsamples were analyzed for microbial community variation between treatments, identifying 16 SCTLD indicator taxa in sediments associated with corals experiencing tissue loss. This study demonstrated that reef sediments can indeed transmit SCTLD through indirect exposure between diseased and healthy corals, and adds credence to the assertion that SCTLD transmission occurs via an infectious agent or agents. This study emphasizes the critical need to understand the roles that sediment microbial communities and coastal development activities may have on the persistence of SCTLD throughout the endemic zone, especially in the context of management and conservation strategies in Florida and the wider Caribbean

Tetrazine-Triggered Release of Carboxylic-Acid-Containing Molecules for Activation of an Anti-inflammatory Drug.

In addition to its use for the study of biomolecules in living systems, bioorthogonal chemistry has emerged as a promising strategy to enable protein or drug activation in a spatially and temporally controlled manner. This study demonstrates the application of a bioorthogonal inverse electron-demand Diels-Alder (iEDDA) reaction to cleave trans-cyclooctene (TCO) and vinyl protecting groups from carboxylic acid-containing molecules. The tetrazine-mediated decaging reaction proceeded under biocompatible conditions with fast reaction kinetics (<2 min). The anti-inflammatory activity of ketoprofen was successfully reinstated after decaging of the nontoxic TCOprodrug in live macrophages. Overall, this work expands the scope of functional groups and the application of decaging reactions to a new class of drugs

Targeting cancer cells overexpressing folate receptors with new terpolymer-based nanocapsules: Toward a novel targeted dna delivery system for cancer therapy

Chemotherapeutics represent the standard treatment for a wide range of cancers. However, these agents also affect healthy cells, thus leading to severe off-target effects. Given the non-selectivity of the commonly used drugs, any increase in the selective tumor tissue uptake would represent a significant improvement in cancer therapy. Recently, the use of gene therapy to completely remove the lesion and avoid the toxicity of chemotherapeutics has become a tendency in oncotherapy. Ideally, the genetic material must be safely transferred from the site of administration to the target cells, without involving healthy tissues. This can be achieved by encapsulating genes into non-viral carriers and modifying their surface with ligands with high selectivity and affinity for a relevant receptor on the target cells. Hence, in this work we evaluate the use of terpolymer-based nanocapsules for the targeted delivery of DNA toward cancer cells. The surface of the nanocapsules is decorated with folic acid to actively target the folate receptors overexpressed on a variety of cancer cells. The nanocapsules demonstrate a good ability of encapsulating and releasing DNA. Moreover, the presence of the targeting moieties on the surface of the nanocapsules favors cell uptake, opening up the possibility of more effective therapies

Temperature-Dependent Nitrous Oxide/Carbon Dioxide Preferential Adsorption in a Thiazolium-Functionalized NU-1000 Metal-Organic Framework

Solvent-assisted ligand incorporation (SALI) of the ditopic linker 5-carboxy-3-(4-carboxybenzyl)thiazolium bromide [(H2PhTz)Br] into the zirconium metal-organic framework NU-1000 [Zr6O4(OH)8(H2O)4(TBAPy)2, where NU = Northwestern University and H4TBAPy = 1,3,6,8-tetrakis(p-benzoic-acid)pyrene], led to the SALIed NU-1000-PhTz material of minimal formula [Zr6O4(OH)6(H2O)2(TBAPy)2(PhTz)]Br. NU-1000-PhTz has been thoroughly characterized in the solid state. As confirmed by powder X-ray diffraction, this material keeps the same three-dimensional architecture of NU-1000 and the dicarboxylic extra linker bridges adjacent [Zr6] nodes ca. 8 Å far apart along the crystallographic c-axis. The functionalized MOF has a BET specific surface area of 1560 m2/g, and it is featured by a slightly higher thermal stability than its parent material (Tdec = 820 vs. 800 K, respectively). NU-1000-PhTz has been exploited for the capture and separation of two pollutant gases: carbon dioxide (CO2) and nitrous oxide (N2O). The high thermodynamic affinity for both gases [isosteric heat of adsorption (Qst) = 25 and 27 kJ mol-1 for CO2 and N2O, respectively] reasonably stems from the strong interactions between these (polar) "stick-like"molecules and the ionic framework. Intriguingly, NU-1000-PhTz shows an unprecedented temperature-dependent adsorption capacity, loading more N2O in the 298 K ≤ T ≤ 313 K range but more CO2 at temperatures falling out of this range. Grand canonical Monte Carlo simulations of the adsorption isotherms confirmed that the preferential adsorption sites of both gases are the triangular channels (micropores) in close proximity to the polar pillar. While CO2 interacts with the thiazolium ring in an "end-on"fashion through its O atoms, N2O adopts a "side-on"configuration through its three atoms simultaneously. These findings open new horizons in the discovery of functional materials that may discriminate between polluting gases through selective adsorption at different temperatures

Longitudinal spin transport in diluted magnetic semiconductor superlattices: the effect of the giant Zeeman splitting

Longitudinal spin transport in diluted magnetic semiconductor superlattices is investigated theoretically. The longitudinal magnetoconductivity (MC) in such systems exhibits an oscillating behavior as function of an external magnetic field. In the weak magnetic field region the giant Zeeman splitting plays a dominant role which leads to a large negative magnetoconductivity. In the strong magnetic field region the MC exhibits deep dips with increasing magnetic field. The oscillating behavior is attributed to the interplay between the discrete Landau levels and the Fermi surface. The decrease of the MC at low magnetic field is caused by the $s-d$ exchange interaction between the electron in the conduction band and the magnetic ions.Comment: 6 pages, 9 figures, submitted to Phys. Rev.

Survey of variation in human transcription factors reveals prevalent DNA binding changes

Published in final edited form as: Science. 2016 Mar 25; 351(6280): 1450–1454. Published online 2016 Mar 24. doi: 10.1126/science.aad2257Sequencing of exomes and genomes has revealed abundant genetic variation affecting the coding sequences of human transcription factors (TFs), but the consequences of such variation remain largely unexplored. We developed a computational, structure-based approach to evaluate TF variants for their impact on DNA binding activity and used universal protein-binding microarrays to assay sequence-specific DNA binding activity across 41 reference and 117 variant alleles found in individuals of diverse ancestries and families with Mendelian diseases. We found 77 variants in 28 genes that affect DNA binding affinity or specificity and identified thousands of rare alleles likely to alter the DNA binding activity of human sequence-specific TFs. Our results suggest that most individuals have unique repertoires of TF DNA binding activities, which may contribute to phenotypic variation.National Institutes of Health; NHGRI R01 HG003985; P50 HG004233; A*STAR National Science Scholarship; National Science Foundatio