Effects of a home-based contingency program on improving academic performance of disadvantaged middle school youths

Research has demonstrated various ways of improving academic performance of students in public-school classrooms (e.g., Barrish, Saunders, & Wolf, 1969), some of which may be clinically effective but not practical within present school systems. A more practical method is the use of a program involving home-based contingencies. Home-based contingencies simply means that: When children are reinforced by their parents for their appropriate behavior and performance at school, school behavior and performance will improve (Broughton, Barton, & Owen;. 1981). The current study employed a program including home-based contingencies modeled after one created by Shumaker, Hovell, and Sherman (1977), and tested the program\u27s effect on academic performance of disadvantaged middle school youths. The independent variable was the home-based contingency component of the program, and the dependent variables were daily report cards, grades, truancy, attendance, and archival data reflecting previous grades, truancy, and attendance. Results indicated that the home-based contingency program significantly increased appropriate school behavior (t(25) = 13.85, p\u3c0.00), but, did not have any substantial impact on grades (t(2) = 1.53, p\u3e0.08), truancy, or attendance

Entanglement frustration in multimode Gaussian states

Bipartite entanglement between two parties of a composite quantum system can be quantified in terms of the purity of one party and there always exists a pure state of the total system that maximizes it (and minimizes purity). When many different bipartitions are considered, the requirement that purity be minimal for all bipartitions gives rise to the phenomenon of entanglement frustration. This feature, observed in quantum systems with both discrete and continuous variables, can be studied by means of a suitable cost function whose minimizers are the maximally multipartite-entangled states (MMES). In this paper we extend the analysis of multipartite entanglement frustration of Gaussian states in multimode bosonic systems. We derive bounds on the frustration, under the constraint of finite mean energy, in the low and high energy limit.Comment: 4 pages, 2 figures. Contribution to "Folding and Unfolding: Interactions from Geometry. Workshop in honour of Giuseppe Marmo's 65th birthday", 8-12 June 2011, Ischia (NA) Ital

Dorsoventral patterning of the Xenopus eye involves differential temporal changes in the response of optic stalk and retinal progenitors to Hh signalling

Background: Hedgehog (Hh) signals are instrumental to the dorsoventral patterning of the vertebrate eye, promoting optic stalk and ventral retinal fates and repressing dorsal retinal identity. There has been limited analysis, however, of the critical window during which Hh molecules control eye polarity and of the temporal changes in the responsiveness of eye cells to these signals. Results: In this study, we used pharmacological and molecular tools to perform stage-specific manipulations of Hh signalling in the developing Xenopus eye. In gain-of-function experiments, most of the eye was sensitive to ventralization when the Hh pathway was activated starting from gastrula/neurula stages. During optic vesicle stages, the dorsal eye became resistant to Hh-dependent ventralization, but this pathway could partially upregulate optic stalk markers within the retina. In loss-of-function assays, inhibition of Hh signalling starting from neurula stages caused expansion of the dorsal retina at the expense of the ventral retina and the optic stalk, while the effects of Hh inhibition during optic vesicle stages were limited to the reduction of optic stalk size. Conclusions: Our results suggest the existence of two competence windows during which the Hh pathway differentially controls patterning of the eye region. In the first window, between the neural plate and the optic vesicle stages, Hh signalling exerts a global influence on eye dorsoventral polarity, contributing to the specification of optic stalk, ventral retina and dorsal retinal domains. In the second window, between optic vesicle and optic cup stages, this pathway plays a more limited role in the maintenance of the optic stalk domain. We speculate that this temporal regulation is important to coordinate dorsoventral patterning with morphogenesis and differentiation processes during eye development

On the classical capacity of quantum Gaussian channels

The set of quantum Gaussian channels acting on one bosonic mode can be classified according to the action of the group of Gaussian unitaries. We look for bounds on the classical capacity for channels belonging to such a classification. Lower bounds can be efficiently calculated by restricting to Gaussian encodings, for which we provide analytical expressions.Comment: 10 pages, IOP style. v2: minor corrections, close to the published versio

Synoptic/planetary-scale interactions and blocking over the North Atlantic Ocean

One segment of work in the past year focused on the diagnosis of a major blocking anticyclone and its interacting synoptic scale circulations that occurred during January 1979 over the North Atlantic Ocean. Another segment focused on the diagnosis of a second explosive cyclone development that occurred over the southeastern United States during the time of block formation. The diagnoses were accomplished using the diagnostic relationship known as the Zwack-Okossi (Z-O) development equation. Results indicate that in both cyclone cases the development occurred as a result of the favorable influence of positive vorticity advection, warm air advection, and latent heat release and ceased when one or more of these influences diminished. The advantages of the Z-O equation are described

A Multi-Objective Approach to Optimize a Periodic Maintenance Policy

The present paper proposes a multi-objective approach to find out an optimal periodic maintenance policy for a repairable and stochastically deteriorating multi-component system over a finite time horizon. The tackled problem concerns the determination of the system elements to replace at each scheduled and periodical system inspection by ensuring the simultaneous minimization of both the expected total maintenance cost and the expected global system unavailability time. It is assumed that in the case of system elements failure they are instantaneously detected and repaired by means of minimal repair actions in order to rapidly restore the system. A non-linear integer mathematical programming model is developed to solve the treated multi-objective problem whereas the Pareto optimal frontier is described by the Lexicographic Goal Programming and the \u3b5-constraint methods. To explain the whole procedure a case study is solved and the related considerations are given

A note on the realignment criterion

For a quantum state in a bipartite system represented as a density matrix, researchers used the realignment matrix and functions on its singular values to study the separability of the quantum state. We obtain bounds for elementary symmetric functions of singular values of realignment matrices. This answers some open problems proposed by Lupo, Aniello, and Scardicchio. As a consequence, we show that the proposed scheme by these authors for testing separability would not work if the two subsystems of the bipartite system have the same dimension.Comment: 11 pages, to appear in Journal of Physics A: Mathematical and Theoretica