304 research outputs found
Dynamic testing of language learning aptitude: an exploratory proof of concept study
This paper provides an example for how online technology can be utilised to increase efficiency and validity of assessment procedures beyond simple computerization of testing. We report the first steps of the development of an online assessment procedure for the measurement of language learning aptitude that is based on the concept of dynamic testing. Online adaptive dynamic tests provide learning opportunities in the test situation, allowing test takers demonstrate their ability to benefit from feedback. Test performance shown in such test procedures has been demonstrated to be more useful in predicting future learning and to represent a more valid indication of test takers’ learning potential. The newly developed online assessment procedure aims at measuring young learner’s ability to improve performance based on inductive reasoning across lexical, morphological and syntactic rules of an artificial language using pictorial stimuli. The test was administered on ten mainland Chinese children aged between 9 and 13. The tentative analysis indicates that the newly developed test is feasible and has the potential to be a useful diagnostic tool for measuring language learning aptitude. We report and discuss insights gained and outline how these will be utilised for the further refinement of this online assessment tool
Bamboo-like Chained Cavities and Other Halogen-Bonded Complexes from Tetrahaloethynyl Cavitands with Simple Ditopic Halogen Bond Acceptors
Halogen bonding provides a useful complement to hydrogen bonding and metal-coordination as a tool for organizing supramolecular systems. Resorcinarenes, tetrameric bowl-shaped cavitands, have been previously shown to function as efficient scaffolds for generating dimeric capsules in both solution and solid-phase, and complicated one-, two-, and three-dimensional frameworks in the solid phase. Tetrahaloethynyl resorcinarenes (bromide and iodide) position the halogen atoms in a very promising crown-like orientation for acting as organizing halogen-bond donors to help build capsules and higher-order networks. Symmetric divalent halogen bond acceptors including bipyridines, 1,4-dioxane, and 1,4-diazabicyclo[2.2.2]octane are very promising halogen bond accepting partners for creating these systems. This report describes the complex structures arising from combining these various systems including self-included dimers, herringbone-packed architectures enclosing medium (186 Ã…3) cavities, and a very intriguing bamboo-like one-dimensional rod with large (683 Ã…3) cavities between adjacent dimeric units. These various structures, all organized through host-host, host-acceptor, and host-solvent interactions highlight the emergent complexity of these types of complexes. As halogen bonds are weaker than hydrogen-bonds, the resulting architectures are harder to predict, and these results provide additional insight into the parameters requiring consideration when designing crystalline supramolecular systems using halogen-bonds as the core organizing principle
Halogen-bonded solvates of tetrahaloethynyl cavitands
The formation and structures of halogen-bonded solvates of three different tetrahaloethynyl cavitands with acetone, chloroform, acetonitrile, DMF and DMSO were prepared and investigated. The inclusion and host-guest behaviour of the resorcinarene cavitands was found to be highly dependent on the flexibility of the ethylene-bridging unit
Effects of Coated Trace Minerals and the Fat Source on Growth Performance, Antioxidant Status, and Meat Quality in Broiler Chickens
Inorganic trace minerals may exacerbate lipid peroxidation, thereby impacting lipid metabolism. This study aimed to compare the effects of inorganic and coated trace minerals in diets with different fat sources, on the performance, slaughter characteristics, and antioxidant status of broiler chickens. A total of 576 21-day-old Abor Acres broiler birds were randomly divided into four dietary treatment groups in a 2 (non-coated and coated trace minerals)×2 (soybean oil and lard) factorial design. Each treatment was replicated 12 times (12 birds per replicate). The results showed that coated minerals significantly improved the average daily gain (ADG) in weight and the feed conversion ratio (p<0.01), increased serum iron, zinc, selenium, and thyroxine contents, increased the activities of glutathione peroxidase, superoxide dismutase, total antioxidant capacity, and lipoprotein lipase (p<0.05), and decreased the serum and muscle malondialdehyde (MDA) contents (p<0.01). The use of soybean oilas the fat source resulted in a high ADG in weight, a low F/G ratio, reduced serum MDA content, and drip loss of breast and leg muscles (p<0.05). In conclusion, the supplementation of coated trace minerals improved growth performance, antioxidant status, trace mineral retention within serum, and lipid metabolism. Additionally, soybean oil also improved the growth performance, antioxidant performance, and meat quality of broilers. The combination of coated trace minerals and soybean oil generated the best growth performance, antioxidant status, and meat quality characteristics
Aspect of Clusters Correlation at Light Nuclei Excited State
The correlation of was probed via measuring the transverse
momentum and width of one , for the first time,
which represents the spatial and dynamical essentialities of the initial
coupling state in Be nucleus. The weighted interaction vertex of
3 reflected by the magnitudes of their relative momentums and relative
emission angles proves the isosceles triangle configuration for 3 at
the high excited energy analogous Hoyle states.Comment: 8 pages, 9 figure
Variation of Tensor Force due to Nuclear Medium Effect
The enhancement of =3(0) state with isospin excited
by the tensor force in the free Li nucleus has been observed, for the
first time, relative to a shrinkable excitation in the Li cluster
component inside its host nucleus. Comparatively, the excitation of
=0(1) state with isospin for these two Li
formations take on an approximately equal excitation strength. The mechanism of
such tensor force effect was proposed due to the intensive nuclear medium role
on isospin =0 state.Comment: 6 pages, 4 figure
Multi-alpha Boson Gas state in Fusion Evaporation Reaction and Three-body Force
The experimental evidence for the Boson gas state in the
C+CMg fusion evaporation reaction is
presented. By measuring the emission spectrum with multiplicity 2 and
3, we provide insight into the existence of a three-body force among
particles. The observed spectrum exhibited distinct tails corresponding to
particles emitted in pairs and triplets consistent well with the
model-calculations of AV18-UX and chiral effective field theory of NV2-3-la*,
indicating the formation of clusters with three-body force in the
Boson gas state.Comment: 7 pages, 6 figure
TRPM2-mediated rise in mitochondrial Zn2+ promotes palmitate-induced mitochondrial fission and pancreatic β-cell death in rodents
Rise in plasma free fatty acids (FFAs) represents a major risk factor for obesity-induced type 2 diabetes. Saturated FFAs cause a progressive decline in insulin secretion by promoting pancreatic β-cell death through increased production of reactive oxygen species (ROS). Recent studies have demonstrated that palmitate (a C16-FFA)-induced rise in ROS causes β-cell death by triggering mitochondrial fragmentation, but the underlying mechanisms are unclear. Using the INS1-832/13 β-cell line, here we demonstrate that palmitate generates the ROS required for mitochondrial fission by activating NOX (NADPH oxidase)-2. More importantly, we show that chemical inhibition, RNAi-mediated silencing and knockout of ROS-sensitive TRPM (transient receptor potential melastatin)-2 channels prevent palmitate-induced mitochondrial fission. Although TRPM2 activation affects the intracellular dynamics of Ca2+ and Zn2+, chelation of Zn2+ alone was sufficient to prevent mitochondrial fission. Consistent with the role of Zn2+, palmitate caused a rise in mitochondrial Zn2+, leading to Zn2+-dependent mitochondrial recruitment of Drp-1 (a protein that catalyses mitochondrial fission) and loss of mitochondrial membrane potential. In agreement with the previous reports, Ca2+ caused Drp-1 recruitment, but it failed to induce mitochondrial fission in the absence of Zn2+. These results indicate a novel role for Zn2+ in mitochondrial dynamics. Inhibition or knockout of TRPM2 channels in mouse islets and RNAi-mediated silencing of TRPM2 expression in human islets prevented FFA/cytokine-induced β-cell death, findings that are consistent with the role of abnormal mitochondrial fission in cell death. To conclude, our results reveal a novel, potentially druggable signalling pathway for FFA-induced β-cell death. The cascade involves NOX-2-dependent production of ROS, activation of TRPM2 channels, rise in mitochondrial Zn2+, Drp-1 recruitment and abnormal mitochondrial fission
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