Miracle-dz/UniFAR-FTUs huggingface dataset:
Misconceptions and Difficulties in the Acquisition of Metalinguistic Knowledge

This paper describes the outcomes of an investigation into the misconceptions and difficulties encountered when learning grammar. The study is based on evidence collected from a class of twelve-year-olds who were engaged upon a workscheme focusing on grammar, andtwo cohortsof PGCE English students undertaking an intensive grammar course. The analysis suggests that learning metalinguistic knowledge can be made problematic for several reasons. Firstly, learning is confounded by the acquired misconceptions which learners bring with them, often misconceptions created by teachers and textbooks. Secondly, there are specific characteristics of English grammar which cause confusion, particularly the mobility of word class. Finally, the process of acquiring metalinguistic knowledge can be hampered by cognitive difficulties related to the conceptual demands of grammar, the transfer of learning from passive to active understanding, and the patterns of inter-connected learning in grammar. The paper suggests that too much professional energy has been attributed to the debate about whether grammar should be taught or not, whilst insufficient research resource has been allocate to investigating how pupils learn. The findings point to a need for development of metalinguistic subject knowledge in teachers and for further research on pupil acquisition of metalinguistic knowledge.
Transfection of the Giardia lamblia double-stranded RNA virus into giardia lamblia by electroporation of a single-stranded RNA copy of the viral genome

The development of a genetic vector for protozoan parasites is a major hurdle yet to be crossed in the study of the molecular and cellular biology of these parasites. We have identified and isolated a double-stranded RNA virus (G. lamblia virus [GLV]) from certain strains of the intestinal parasitic protozoan Giardia lamblia (A. L. Wang and C. C. Wang, Mol. Biochem. Parasitol. 21:269-276, 1986), which is capable of infecting other virus-free strains of G. lamblia (R. L. Miller, A. L. Wang, and C. C. Wang, Exp. Parasitol. 66:118-123, 1988). Here we demonstrate that G. lamblia can be infected with GLV by electroporating uninfected cells with purified single-stranded RNA (E. S. Furfine, T. C. White, A. L. Wang, and C. C. Wang, Nucleic Acids Res. 17:7453-7467, 1989) representing a full-length copy of one strand of the GLV double-stranded RNA genome. To the best of our knowledge, this is the first demonstration in vivo that a single-stranded RNA is a competent replicative intermediate for this class of double-stranded RNA virus. In addition, this result represents the first long-term transfection of a protozoan by a single species of RNA and will hopefully expedite the development of GLV as a genetic transfecting vector.
Novel Electrospun Polylactic Acid Nanocomposite Fiber Mats with Hybrid Graphene Oxide and Nanohydroxyapatite Reinforcements Having Enhanced Biocompatibility

Graphene oxide (GO) and a nanohydroxyapatite rod (nHA) of good biocompatibility were incorporated into polylactic acid (PLA) through electrospinning to form nanocomposite fiber scaffolds for bone tissue engineering applications. The preparation, morphological, mechanical and thermal properties, as well as biocompatibility of electrospun PLA scaffolds reinforced with GO and/or nHA were investigated. Electron microscopic examination and image analysis showed that GO and nHA nanofillers refine the diameter of electrospun PLA fibers. Differential scanning calorimetric tests showed that nHA facilitates the crystallization process of PLA, thereby acting as a nucleating site for the PLA molecules. Tensile test results indicated that the tensile strength and elastic modulus of the electrospun PLA mat can be increased by adding 15 wt % nHA. The hybrid nanocomposite scaffold with 15 wt % nHA and 1 wt % GO fillers exhibited higher tensile strength amongst the specimens investigated. Furthermore, nHA and GO nanofillers enhanced the water uptake of PLA. Cell cultivation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and alkaline phosphatase tests demonstrated that all of the nanocomposite scaffolds exhibit higher biocompatibility than the pure PLA mat, particularly for the scaffold with 15 wt % nHA and 1 wt % GO. Therefore, the novel electrospun PLA nanocomposite scaffold with 15 wt % nHA and 1 wt % GO possessing a high tensile strength and modulus, as well as excellent cell proliferation is a potential biomaterial for bone tissue engineering applications.
The Response of Concrete to Shock-Loading

A series of plate impact experiments have been performed to assess the dynamic behaviour of dry and water saturated concrete under shock‐loading. Information was obtained on the Hugoniot curve and dynamic shear properties using manganin gauges. This extends our previous data obtained on cement paste, mortar, and micro‐concrete to full‐size concrete. Despite the varying heterogeneous composition of concrete it has been found that all materials Hugoniot curves lie within a close range in Stress—Particle Velocity space (σ‐up).
A Set of Principles for Conducting and Evaluating Interpretive Field Studies in Information Systems

This article discusses the conduct and evaluatoin of interpretive research in information systems. While the conventions for evaluating information systems case studies conducted according to the natural science model of social science are now widely accepted, this is not the case for interpretive field studies. A set of principles for the conduct and evaluation of interpretive field research in information systems is proposed, along with their philosophical rationale. The usefulness of the principles is illustrated by evaluating three published interpretive field studies drawn from the IS research literature. The intention of the paper is to further reflect and debate on the important subject of grounding interpretive research methodology.
Pluronics and MDR Reversal: An Update

Multidrug resistance (MDR) remains one of the biggest obstacles for effective cancer therapy. Currently there are only few methods that are available clinically that are used to bypass MDR with very limited success. In this review we describe how MDR can be overcome by a simple yet effective approach of using amphiphilic block copolymers. Triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), arranged in a triblock structure PEO-PPO-PEO, Pluronics or “poloxamers”, raised a considerable interest in the drug delivery field. Previous studies demonstrated that Pluronics sensitize MDR cancer cells resulting in increased cytotoxic activity of Dox, paclitaxel, and other drugs by 2–3 orders of magnitude. Pluronics can also prevent the development of MDR in vitro and in vivo. Additionally, promising results of clinical studies of Dox/Pluronic formulation reinforced the need to ascertain a thorough understanding of Pluronic effects in tumors. These effects are extremely comprehensive and appear on the level of plasma membranes, mitochondria, and regulation of gene expression selectively in MDR cancer cells. Moreover, it has been demonstrated recently that Pluronics can effectively deplete tumorigenic intrinsically drug-resistant cancer stem cells (CSC). Interestingly, sensitization of MDR and inhibition of drug efflux transporters is not specific or selective to Pluronics. Other amphiphilic polymers have shown similar activities in various experimental models. This review summarizes recent advances of understanding the Pluronic effects in sensitization and prevention of MDR.
Accuracy of head motion compensation for the HRRT: Comparison of methods

Motion correction in PET has become more important as system resolution has improved. The purpose of this study was to evaluate the accuracy of three motion compensation methods, event-by-event motion compensation with list-mode reconstruction (MOLAR), frame-based motion correction, and post-reconstruction image registration. Motion compensated image reconstructions were carried out with simulated HRRT data, using a range of motion information based on human motion data. ROI analyses in high contrast regions were performed to evaluate the accuracy of all the motion compensation methods, with particular attention to within-frame motion. Our study showed that MOLAR with list-mode based motion correction using accurate motion data can reliably correct for all reasonable head motions. Over all motions, the average ROI count was within 0.1±4.2% and 0.7±0.9% of the reference, no-motion value for two different ROIs. The location of the ROI centroid was found to be within 0.7±0.3mm of that of the reference image for the raphe nucleus. Frame-based motion compensation and post-reconstruction image registration were able to correct for small (<5mm), but the ROI intensity begins to deteriorate for medium motions (5-10mm), especially for small brain structures such as the raphe nucleus. For large (>10mm) motions, the average centroid locations of the raphe nucleus ROI had an offset error of 1.5±1.8mm and 1.8±1.8mm for each of the frame-based methods. For each frame-based method, the decrease in the average ROI intensity was 16.9±4.3% and 20.2±9.9% respectively for the raphe nucleus, and was 5.5±2.2% and 7.4±0.2% for putamen. Based on these data, we conclude that event-by-event based motion correction works accurately for all reasonable motions, whereas frame-based motion correction is accurate only when the within-frame motion is less than 10mm.
Glucose Oxidation Modulates Anoikis and Tumor Metastasis

ABSTRACT Cancer cells exhibit altered glucose metabolism characterized by a preference for aerobic glycolysis or the Warburg effect, and the cells resist matrix detachment-induced apoptosis, which is called anoikis, a barrier to metastasis. It remains largely unclear whether tumor metabolism influences anoikis and metastasis. Here we show that when detached from the matrix, untransformed mammary epithelial cells undergo metabolic reprogramming by markedly upregulating pyruvate dehydrogenase (PDH) kinase 4 (PDK4) through estrogen-related receptor gamma (ERRγ), thereby inhibiting PDH and attenuating the flux of glycolytic carbon into mitochondrial oxidation. To decipher the significance of this metabolic response, we found that depletion of PDK4 or activation of PDH increased mitochondrial respiration and oxidative stress in suspended cells, resulting in heightened anoikis. Conversely, overexpression of PDKs prolonged survival of cells in suspension. Therefore, decreased glucose oxidation following cell detachment confers anoikis resistance. Unlike untransformed cells, most cancer cells demonstrate reduced glucose oxidation even under attached conditions, and thus they inherently possess a survival advantage when suspended. Normalization of glucose metabolism by stimulating PDH in cancer cells restores their susceptibility to anoikis and impairs their metastatic potential. These results suggest that the Warburg effect, more specifically, diminished glucose oxidation, promotes anoikis resistance and metastasis and that PDKs are potential targets for antimetastasis therapy.
Secondary fluorescence in electron probe microanalysis of material couples

We describe a semi-analytical method for the fast calculation of secondary fluorescence in electron probe microanalysis of material couples. The calculation includes contributions from primary K-, L- and M-shell characteristic x-rays and bremsstrahlung photons. The required physical interaction parameters (subshell partial cross sections, attenuation coefficients, etc) are extracted from the database of the Monte Carlo simulation code system PENELOPE. The calculation makes use of the intensities of primary photons released in interactions of beam electrons and secondary electrons. Since these intensities are not readily available and do not allow analytical calculation, they are generated from short Monte Carlo simulation runs. The reliability of the proposed calculation method has been assessed by comparing calculated, distance-dependent k-ratios with experimental data available in the literature and with results from simulations with PENELOPE. Numerical results are found to be in close agreement with both simulated and experimental data.
Frontiers in Computational Neuroscience

only addressed the conservation of the ISI distribution, or the firing rate profile (Smith and Kohn, 2008), up to a precision determined by the dither width chosen. In the present study we propose dithering methods which simultaneously conserve both features with a higher level of precision. The estimation of the intensity function within or across trials certainly only constitutes an approximate source of information, however we show that it can and should be used in the implementation of dithering methods. It may be argued that provided the rate profile, one can simply sample from it. That is, use it along with the ISI distribution, as a parameter of a chosen model of spike generation. The problems with this are that the spike count is not necessarily preserved, and strong assumptions on the process itself have to be made; for example that it is a Poisson process. The issues can be overcome if the estimated features of the process are integrated into the dithering method. The immediate benefit of having an estimate of the spike rate is that the process can be approximately transformed to a unit rate stationary process through rescaling of the time axis; a mapping to operational time. Once a process is stationary, the constraints on the dithering method are considerably relaxed. We begin our study by indicating how a time invariant dithering applied in operational time instead of real time leads to a perfect conservation of the rate profile. However, the effective transformation undergone by the spikes in real time is not entirely obvious. We address this issue and demonstrate how a uniform dither in operational time maps to a variable range, non-uniform dither following the rate profile itself, in real time. This is verified through simulations. A fixed time scale hypothesis can be tested for by fixing the dither range in real time and replicating directly the effect of an operational time dither by modulating the dithering profile according
Nutrigerontology: why we need a new scientific discipline to develop diets and guidelines to reduce the risk of aging-related diseases

Many diets and nutritional advice are circulating, often based on short‐ or medium‐term clinical trials and primary outcomes, like changes in LDL cholesterol or weight. It remains difficult to assess which dietary interventions can be effective in the long term to reduce the risk of aging‐related disease and increase the (healthy) lifespan. At the same time, the scientific discipline that studies the aging process has identified some important nutrient‐sensing pathways that modulate the aging process, such as the mTOR and the insulin/insulin‐like growth factor signaling pathway. A thorough understanding of the aging process can help assessing the efficacy of dietary interventions aimed at reducing the risk of aging‐related diseases. To come to these insights, a synthesis of biogerontological, nutritional, and medical knowledge is needed, which can be framed in a new discipline called ‘nutrigerontology’.
Sonic Hedgehog Has a Dual Effect on the Growth of Retinal Ganglion Axons Depending on Its Concentration

The stereotypical projection of retinal ganglion cell (RGC) axons to the optic disc has served as a good model system for studying axon guidance. By both in vitro and in vivo experiments, we show that a secreted molecule, Sonic hedgehog (Shh), may play a critical role in the process. It is expressed in a dynamic pattern in the ganglion cell layer with a relatively higher expression in the center of the retina. Through gel culture and stripe assays, we show that Shh has a dual effect on RGC axonal growth, acting as a positive factor at low concentrations and a negative factor at high concentrations. Results from time-lapse video microscopic and stripe assay experiments further suggest that the effects of Shh on axons are not likely attributable to indirect transcriptional regulation by Shh. Overexpression of Shh protein or inhibition of Shh function inside the retina resulted in a complete loss of centrally directed projection of RGC axons, suggesting that precise regulation of Shh level inside the retina is critical for the projection of RGC axons to the optic disc.
Sub-Alfvénic Nonideal MHD Turbulence Simulations with Ambipolar Diffusion. I. Turbulence Statistics

Most numerical investigations on the role of magnetic fields in turbulent molecular clouds (MCs) are based on ideal magnetohydrodynamics (MHD). However, MCs are weakly ionized, so that the timescale required for the magnetic field to diffuse through the neutral component of the plasma by ambipolar diffusion (AD) can be comparable to the dynamical timescale. We have performed a series of 2563 and 5123 simulations on supersonic but sub-Alfvénic turbulent systems with AD using the heavy-ion approximation developed by Li and coworkers. Our calculations are based on the assumption that the number of ions is conserved, but we show that these results approximately apply to the case of time-dependent ionization in molecular clouds as well. Convergence studies allow us to determine the optimal value of the ionization mass fraction when using the heavy-ion approximation for low Mach number, sub-Alfvénic turbulent systems. We find that ambipolar diffusion steepens the velocity and magnetic power spectra compared to the ideal MHD case. Changes in the density PDF, total magnetic energy, and ionization fraction are determined as a function of the AD Reynolds number. The power spectra for the neutral gas properties of a strongly magnetized medium with a low AD Reynolds number are similar to those for a weakly magnetized medium; in particular, the power spectrum of the neutral velocity is close to that for Burgers turbulence.
Common Origins of Hippocampal Ivy and Nitric Oxide Synthase Expressing Neurogliaform Cells

GABAergic interneurons critically regulate cortical computation through exquisite spatiotemporal control over excitatory networks. Precision of this inhibitory control requires a remarkable diversity within interneuron populations that is largely specified during embryogenesis. Although interneurons expressing the neuronal isoform of nitric oxide synthase (nNOS) constitute the largest hippocampal interneuron cohort their origin and specification remain unknown. Thus, as neurogliaform cells (NGC) and Ivy cells (IvC) represent the main nNOS+ interneurons, we investigated their developmental origins. Although considered distinct interneuron subtypes, NGCs and IvCs exhibited similar neurochemical and electrophysiological signatures, including NPY expression and late spiking. Moreover, lineage analyses, including loss-of-function experiments and inducible fate-mapping, indicated that nNOS+ IvCs and NGCs are both derived from medial ganglionic eminence (MGE) progenitors under control of the transcription factor Nkx2-1. Surprisingly, a subset of NGCs lacking nNOS arises from caudal ganglionic eminence (CGE) progenitors. Thus, while nNOS+ NGCs and IvCs arise from MGE progenitors, a CGE origin distinguishes a discrete population of nNOS− NGCs.
Formation of bubbles and droplets in microfluidic systems

This mini-review reports the recent advances in the hydrodynamic techniques for formation of bubbles of gas in liquid in microfluidic systems. Systems comprising ducts that have widths of the order of 100 micrometers produce suspensions of bubbles with narrow size distributions. Certain of these systems have the ability to tune the volume fraction of the gaseous phase – over the whole range from zero to one. The rate of flow of the liquids through the devices determines the mechanism of formation of the bubbles – from break-up controlled by the rate of flow of the liquid (at low capillary numbers, and in the presence of strong confinement by the walls of the microchannels), to dynamics dominated by inertial effects (at high Weber numbers). The region of transition between these two regimes exhibits nonlinear behaviours, with period doubling cascades and irregular bubbling as prominent examples. Microfluidic systems provide new and uniquely controlled methods for generation of bubbles, and offer potential applications in micro-flow chemical processing, synthesis of materials, and
[Functional assessment of patients with hypertrophic cardiomyopathy by maximal oxygen consumption].

INTRODUCTION AND OBJECTIVES Differences between anatomical severity and clinical manifestations are frequent in patients with hypertrophic cardiomyopathy. Our objective was to assess functional capacity in a consecutive group of patients with hypertrophic cardiomyopathy measuring exercise aerobic parameters, as well as clinical and echocardiographic variables. PATIENTS AND METHOD We studied 98 consecutive patients with hypertrophic cardiomyopathy. All patients underwent both echocardiographic and cardiopulmonary exercise testing. The control group consisted of 22 untrained persons. We studied exercise capacity by analyzing maximal oxygen consumption and aerobic functional capacity, among other variables. RESULTS Patients with hypertrophic cardiomyopathy attained significantly lower maximal oxygen consumption values than controls (24.1 5.9 vs 36.4 5.9 ml/kg/min; p = 0.0001). Maximal aerobic capacity was significantly different among patients with NYHA functional capacity class I, II or III (78.9 13.5%; 71.9 14.7%; 63.9 15.7%; p = 0.009). However, considerable overlap was found between groups in maximal aerobic capacity. Functional impairment was greater in patients with left ventricular thickness > 20 mm, ejection fraction < 50%, left atrial dimension > 45 mm and pseudonormal or restrictive transmitral flow pattern. CONCLUSIONS Patients with hypertrophic cardiomyopathy show significant functional impairment, which is difficult to detect from their clinical manifestations. Optimal assessment requires cardiopulmonary exercise testing.
Disruptive sexual selection on male nuptial coloration in an experimental hybrid population of cichlid fish

Theory suggests that genetic polymorphisms in female mating preferences may cause disruptive selection on male traits, facilitating phenotypic differentiation despite gene flow, as in reinforcement or other models of speciation with gene flow. Very little experimental data have been published to test the assumptions regarding the genetics of mate choice that such theory relies on. We generated a population segregating for female mating preferences and male colour dissociated from other species differences by breeding hybrids between species of the cichlid fish genus Pundamilia. We measured male mating success as a function of male colour. First, we demonstrate that non-hybrid females of both species use male nuptial coloration for choosing mates, but with inversed preferences. Second, we show that variation in female mating preferences in an F2 hybrid population generates a quadratic fitness function for male coloration suggestive of disruptive selection: intermediate males obtained fewer matings than males at either extreme of the colour range. If the genetics of female mate choice in Pundamilia are representative for those in other species of Lake Victoria cichlid fish, it may help explain the origin and maintenance of phenotypic diversity despite some gene flow.