The Impact of Interest in School on Educational Success in Portugal

Notwithstanding increased educational expenditure, Portugal continues to record poor educational outcomes. Underlining the weak expenditure-educational success link, a large body of work in educational economics displays that there is a tenuous relationship between a range of school inputs and cognitive achievement. Among others, the inability to establish a clear link between inputs and success has been attributed to the difficulty of controlling for unobserved attributes such as ability, motivation and interest. Against this background, and inspired by a large body of work in educational psychology which explicitly measures constructs such as educational motivation and interest, this paper examines whether a child’s interest in school has any bearing on educational success after controlling for the kinds of variables typically used in educational economics analyses. We rely on two data sets collected in Portugal in 1998 and 2001 and examine the interest-educational success link using both cross-section and panel data. Our estimates suggest that after controlling for time-invariant unobservable traits and for the simultaneous determination of interest and achievement, there is little support for the idea that prior interest in school has a bearing on future educational success.schooling, Portugal, educational outcomes, interest in school

NUMERICAL ANALYSIS OF DEVELOPING TURBULENT FLOW IN A CLOSED COMPOUND CHANNEL

The study of turbulence characteristics in compound channels is still focus of attention. A lot of experimental results have been produced. Main results have revealed a mixing layer formation between main subchannel and the gap region, implying the flow might be ruled by local scales. The outcomes have pointed to the instabilities of mixing layer are responsible for large structures formation between main channel and narrow gap. Furthermore, the periodical behavior of these structures seems to be ruled by mean mixing layer characteristics, as velocity difference, velocity of convection and mixing layer thickness. By using ANSYS-CFX-12, with unsteady Reynolds Average Navier-Stokes and as turbulence model Spalart-Allmaras (SA), a compound channel was studied. Numerical results predicted velocity profile with high vorticity peaks and flow instabilities starting at L/Dh = 15

Gut immune dysfunction through impaired innate pattern recognition receptor expression and gut microbiota dysbiosis in chronic SIV infection.

HIV targets the gut mucosa early in infection, causing immune and epithelial barrier dysfunction and disease progression. However, gut mucosal sensing and innate immune signaling through mucosal pattern recognition receptors (PRRs) during HIV infection and disease progression are not well defined. Using the simian immunodeficiency virus (SIV)-infected rhesus macaque model of AIDS, we found a robust increase in PRRs and inflammatory cytokine gene expression during the acute SIV infection in both peripheral blood and gut mucosa, coinciding with viral replication. PRR expression remained elevated in peripheral blood following the transition to chronic SIV infection. In contrast, massive dampening of PRR expression was detected in the gut mucosa, despite the presence of detectable viral loads. Exceptionally, expression of Toll-like receptor 4 (TLR4) and TLR8 was downmodulated and diverged from expression patterns for most other TLRs in the gut. Decreased mucosal PRR expression was associated with increased abundance of several pathogenic bacterial taxa, including Pasteurellaceae members, Aggregatibacter and Actinobacillus, and Mycoplasmataceae family. Early antiretroviral therapy led to viral suppression but only partial maintenance of gut PRRs and cytokine gene expression. In summary, SIV infection dampens mucosal innate immunity through PRR dysregulation and may promote immune activation, gut microbiota changes, and ineffective viral clearance

Turbulent separation upstream of a forward-facing step

The turbulent flow over a forward-facing step is studied using two-dimensional time-resolved particle image velocimetry. The structure and behaviour of the separation region in front of the step is investigated using conditional averages based on the area of reverse flow present. The relation between the position of the upstream separation and the two-dimensional shape of the separation region is presented. It is shown that when of ‘closed' form, the separation region can become unstable resulting in the ejection of fluid over the corner of the step. The separation region is shown to grow simultaneously in both the wall-normal and streamwise directions, to a point where the maximum extent of the upstream position of separation is limited by the accompanying transfer of mass over the step corner. The conditional averages are traced backwards in time to identify the average behaviour of the boundary-layer displacement thickness leading up to such events. It is shown that these ejections are preceded by the convection of low-velocity regions from upstream, resulting in a three-dimensional interaction within the separation region. The size of the low-velocity regions, and the time scale at which the separation region fluctuates, is shown to be consistent with the large boundary layer structures observed in the literature. Instances of a highly suppressed separation region are accompanied by a steady increase in velocity in the upstream boundary laye

Light propagation in (2+1)-dimensional electrodynamics: the case of nonlinear constitutive laws

We scrutinize the geometrical properties of light propagation inside a nonlinear medium modeled by a fully covariant electromagnetic theory in $2+1$-dimensions. After setting the nonlinear constitutive relations, the phase velocity and the polarization of waves are derived and three special cases are analyzed in details. In spite of the dimensional reduction, our model still presents phenomena like one-way propagation, controlled opacity among others for a large class of dielectric and magneto-electric parameters.Comment: 9 pages, 7 figure

NUMERICAL INVESTIGATION OF HEAT TRANSFER IN A TURBULENT FLOW IN CHANNELS WITH GAP

Turbulent flow in channels with gap is still a challenge for engineering. The velocity fluctuations and the appearance of coherent structures have been playing a major role in forced convective heat transfer process between the warm tube walls and the cooling fluid. In this paper numerical simulation of non-isothermal turbulent flow in a rectangular channel containing only one tube was performed. Unsteady Reynolds Navier-Stokes along with the energy equation were applied to model the problem. In order to overcome the closure problem the turbulence was modeled applying SAS model. The simulated geometry consists of a heated cylindrical tube, placed 10 mm from the bottom wall of the rectangular duct. The fluid flows externally to the heated tube along the mainstream direction. The channel’s length was based on the tube diameter, yielding L/D equal 80

Neurobehavioral Evaluation of Mice Dosed With Water Hemlock Green Seeds and Tubers

Water hemlock are plants of the genus Cicuta and are toxic to animals and humans. The primary toxin is cicutoxin, which is abundant in the tubers, but less abundant in other parts of the plant. Other cicutoxin-like compounds, such as cicutols, which may also contribute to the toxicity of water hemlock, are more abundant in non-tuber plant parts. The objective of this study was to determine the toxicity of different parts of water hemlock and characterize their effects on motor function/coordination in mice. An aqueous extract of green seeds, dry seeds, tubers, flowers and stems of water hemlock was dosed orally to mice to determine their acute toxicity. The results indicated that only the green seeds and tubers were sufficiently toxic to animals to induce seizures and death. The LD50 for tubers and green seeds was 17 mg/kg and 1320 mg/kg, respectively. Several tests were used to evaluate motor function and behavior in treated mice including rotarod, tremor monitor, and open field. The animals were evaluated before dosing and 30, 90, 120, 150, 180, 240, and 300 min after dosing. Water hemlock affected muscle function of mice, including their balance and motility on a rotarod, motor activity, and exploratory and anxiety-related (i.e., thigmotaxis) behaviors in an open field. Seizures interspersed with central nervous system (CNS) motor depression were observed in animals poisoned by water hemlock. Extracts from tubers were especially potent in causing a decrease in motor activity and resultant depression, while periodically provoking seizures. Further research is needed to identify, quantitate, and purify cicutoxin and the other polyacetylene compounds from the various water hemlock plant parts to evaluate their toxicity and effects on motor function

Optimal mode decomposition for unsteady flows

A new method, herein referred to as optimal mode decomposition (OMD), of finding a linear model to describe the evolution of a fluid flow is presented. The method estimates the linear dynamics of a high-dimensional system which is first projected onto a subspace of a user-defined fixed rank. An iterative procedure is used to find the optimal combination of linear model and subspace that minimizes the system residual error. The OMD method is shown to be a generalization of dynamic mode decomposition (DMD), in which the subspace is not optimized but rather fixed to be the proper orthogonal decomposition (POD) modes. Furthermore, OMD is shown to provide an approximation to the Koopman modes and eigenvalues of the underlying system. A comparison between OMD and DMD is made using both a synthetic waveform and an experimental data set. The OMD technique is shown to have lower residual errors than DMD and is shown on a synthetic waveform to provide more accurate estimates of the system eigenvalues. This new method can be used with experimental and numerical data to calculate the ‘optimal' low-order model with a user-defined rank that best captures the system dynamics of unsteady and turbulent flow