Do Accountability and Voucher Threats Improve Low-Performing Schools?

In this paper we study the effects of the threat of school vouchers and school stigma in Florida on the performance of "low-performing" schools using student-level data from a subset of districts. Estimates of the change in school-level high-stakes test scores from the first year of the reform are consistent with the early results used by the state of Florida to claim large-scale improvements associated with the threat of voucher assignment. However, we also find that much of this estimated effect may be due to other factors. While we estimate a small relative improvement in reading scores on the high-stakes test for voucher-threatened/stigmatized schools, we estimate a much smaller relative improvement on a lower-stakes, nationally norm-referenced, test. Further, the relative gains in reading scores are explained largely by changing student characteristics. We find more evidence for a positive differential effect on math test scores on both the low- and highstakes tests, however, the results from the lower-stakes test appear primarily limited to students in the high-stakes grade. Finally, we find some evidence that the relative improvements following the introduction of the A Plan by low-performing schools were more due to the stigma of receiving the low grade rather than the threat of vouchers.

A STUDY OF THE PERCEPTUAL BELIEFS AND THE USE OF INFORMATION AND COMMUNICATION TECHNOLOGY FOR LANGUAGE LEARNING

This paper is a temporary report of a project investigating the ICT gadgets in a survey study involving students of Senior High Schools in Central Java, Indonesia. The purpose of this study is to investigate how ICT is perceived and used by high school students as well as to disclose how the students have made use of the technological gadgets for language learning-related activities. The study employs a mixed method by which data were garnered from questionnaire surveys and focus group discussion. This is reported in the very end of the project stages and the results of which suggest that the research subjects perceive the ICT very positively and that, overall, respondents have frequently used them for various dayto-day activities. Another finding also suggests that the majority of respondents admit that they use the gadgets for various learning-related activities despite less so for learning English, bringing with it an implication on the change of policy by schools or educational policy makers to consider integrating the technology into a more purposeful learning uses

Palatini wormholes and energy conditions from the prism of General Relativity

Wormholes are hypothetical shortcuts in spacetime that in General Relativity unavoidably violate all of the pointwise energy conditions. In this paper, we consider several wormhole spacetimes that, as opposed to the standard \emph{designer} procedure frequently employed in the literature, arise directly from gravitational actions including additional terms resulting from contractions of the Ricci tensor with the metric, and which are formulated assuming independence between metric and connection (Palatini approach). We reinterpret such wormhole solutions under the prism of General Relativity and study the matter sources that thread them. We discuss the size of violation of the energy conditions in different cases, and how this is related to the same spacetimes when viewed from the modified gravity side.Comment: 13 pages, 7 figures. Significant changes mainly in introduction and conclusions. Accepted for publication in Eur. Phys. J.

Quantum quenches of ion Coulomb crystals across structural instabilities

Quenches in an ion chain can create coherent superpositions of motional states across the linear-zigzag structural transition. The procedure has been described in [Phys. Rev. A 84, 063821 (2011)] and makes use of spin-dependent forces, so that a coherent superposition of the electronic states of one ion evolves into an entangled state between the chain's internal and external degrees of freedom. The properties of the crystalline state so generated are theoretically studied by means of Ramsey interferometry on one ion of the chain. An analytical expression for the visibility of the interferometric measurement is obtained for a chain of arbitrary number of ions and as a function of the time elapsed after the quench. Sufficiently close to the linear-zigzag instability the visibility decays very fast, but exhibits revivals at the period of oscillation of the mode that drives the structural instability. These revivals have a periodicity that is independent of the crystal size, and they signal the creation of entanglement by the quantum quench.Comment: 14 pages, 8 figures; added a paragraph in the introduction providing more background, added paragraph at the end of Sec. IV discussing experimental parameter

Optimal Growth and Characterization of Cobalt Sulphide Thin Films Fabricated Using the Chemical Bath Deposition Technique

In this work, chemical bath deposition technique was used to deposit thin films of cobalt sulphide on glass substrate from the aqueous solution containing 1M of cobalt chloride, 1M of thiourea, 1M of ammonia and 1M of ethylene diamine tetra acetate (EDTA) which served as the complexing agent. The optical measurement was carried out on the deposited films using M501 single beam scanning UV/visible spectrophotometer. The results show that the films have high absorbance towards the UV-region whereas it recorded low transmittance value in the same region. The films also exhibited poor reflectance value towards the UV-region. The band gap energy value was found to be 1.72eV. The films were observed to have thickness value range of 1.122µm to 1.152µm. These properties made the material to be a good candidate for photovoltaic and opto-electronic applications. Keywords:Cobaltsulphide, absorbance, transmittance,reflectance, solid state property, band gap energy, thin fil

Electronic and structural distortions in graphene induced by carbon vacancies and boron doping

We present an ab initio study on the structural and electronic distortions of modified graphene by creation of vacancies, inclusion of boron atoms, and the coexistence of both, by means of thermodynamics and band structure calculations. In the case of coexistence of boron atoms and vacancy, the modified graphene presents spin polarization only when B atoms locate far from vacancy. Thus, when a boron atom fills single- and di-vacancies, it suppresses the spin polarization of the charge density. In particular when B atoms fill a di-vacancy a new type of rearrangement occurs, where a stable BC4 unit is formed inducing important out of plane distortions to graphene. All these findings suggest that new chemical modifications to graphene and new type of vacancies can be used for interesting applications such as sensor and chemical labeling.Comment: 22 pages, 9 figures and 3 table

Pattern formation in binary fluid mixtures induced by short-range competing interactions

Molecular dynamics simulations and integral equation calculations of a simple equimolar mixture of diatomic molecules and monomers interacting via attractive and repulsive short-range potentials show the existence of pattern formation (microheterogeneity), mostly due to depletion forces away from the demixing region. Effective site-site potentials extracted from the pair correlation functions using an inverse Monte Carlo approach and an integral equation inversion procedure exhibit the features characteristic of a short-range attractive and long-range repulsive potential. When charges are incorporated into the model, this becomes a coarse grained representation of a room temperature ionic liquid, and as expected, intermediate range order becomes more pronounced and stable

Knowledge, Attitudes and Practices towards the Use of Iron and Folic Acid Supplements among Pregnant and Lactating Women in Dar es Salaam

The current study investigated knowledge, attitudes and practices (KAP) regarding the use of iron and folic acid (IFA) supplements among pregnant and lactating women living with Human Immunodeficiency Virus (HIV) in Dar es Salaam. A cross-sectional survey involved 294 pregnant and lactating women attending Prevention of Mother-To Child Transmission (PMTCT) clinics. A semi-structured questionnaire was used to collect data from the subjects. The data were analysed using SPSS. Multivariate regression analysis was carried out to determine factors associated with IFA supplement use among the study subjects. The findings indicated that knowledge of IFA supplement use among the subjects was good (92.2%). Most of the respondents (89.8%) had appropriate perceptions of IFA supplements. The subjects also showed positive attitudes towards the use of IFA supplements during pregnancy and lactation. However, practices towards the use of supplements were not satisfactory. It was further revealed that only 15.2% of the women received supplements during pregnancy and a few weeks after delivery as recommended. Women claimed the main barriers towards using the supplements were bad taste (46.7%) and nausea (45.2%). The multivariate logistic regression model showed that factors like being a businesswoman, comfortable use of the supplements and experiencing any barriers were significantly associated with practices on the use of the supplements.  Thus, healthcare workers should clear up the misconceptions about using the supplements and instruct women on how to manage their potential side effects as they have been doing with other conditions or illnesses.  Keywords:     Iron, folic acid, anaemia, supplements, knowledge, attitude, practice, pregnant, lactating wome