Modularity and part-whole compositionality for computing the state semantics of statecharts

The paper discusses modularity and compositionality issues in state-based modeling formalisms and presents related recent research results. Part-Whole Statecharts provide modular constructs to traditional Statecharts in order to allow incremental and fully reusable composition of behavioral abstractions, enforcing explicitly the coordinated systemic behavior and bringing benefits to subsequent modeling and implementation phases. The paper shows that Part-Whole Statecharts have a computable semantics, which can be specified through a constraint-driven specification method. Such a method allows to specify and verify the intended meaning of states directly at design time, thus avoiding to employ less effective verification techniques, such as exhaustive testing or model checking

Correlation of art as a means of developing skills in the content areas for the educable mentally retarded on the intermediate level

In this paper the writer has shown how recent developments have supplied some interesting and useful approaches toward a theory of the psychology of art as a means of developing skills in the content areas of the curriculum for the Educable Mentally Retarded on the intermediate level. The purpose of the study is to ascertain factors related to the nature of the child; characteristics associated with the conditions of mental retardation; self-development through art, and the correlation of art activities with the units and activities in other subjects. By so doing, the writer feels that the basic needs of the Educable Mentally Retarded will be better satisfied within a regular classroom situation

Representaciones de la física, su enseñanza y aprendizaje. Un estudio con estudiantes de nivel secundario y universitario

Se describe un estudio exploratorio cuyo objetivo fue identificar, caracterizar y describir las representaciones sociales sobre la física, su enseñanza y aprendizaje en alumnos de diferentes niveles de escolaridad de modo de obtener indicadores para la construcción de los instrumentos a utilizar en las fases siguientes de la investigación. Se empleó una metodología cualitativa con un enfoque descriptivo e interpretativo. Cinco grupos de alumnos de nivel secundario y universitario básico (n=172) respondieron a una prueba individual de evocación libre. Las producciones se analizaron empleando una técnica de análisis de contenido. Se identificaron representaciones relativas a las dimensiones cognitiva, pedagógica, afectiva y sociocultural

The effect of antifreeze (ethylene glycol) on the survival and the life cycle of two species of necrophagous blowflies (Diptera: Calliphoridae)

Entomotoxicology involves the analysis of the presence and the effects of toxicological substances in necrophagous insects. Results obtained by entomotoxicological studies may assist in the investigation of both the causes and the time of death of humans and animals. Ethylene glycol (EG) is easy to purchase, sweet and extremely toxic. It may be consumed accidentally or purposefully, in an attempt to cause death for suicidal or homicidal intent. Several cases report fatalities of humans and animals. The present study is the first to examine the effects of EG on the survival, developmental rate and morphology of two blowfly species, (Diptera: Calliphoridae) typically found on corpses and carcasses: Lucilia sericata (Meigen) and L. cuprina (Wiedemann). Both species were reared on substrates (beef liver) spiked with three different concentrations of EG that could cause death in either a human or cat: 1/2LD50 (T1), LD50 (T2), 2LD50 (T3), in addition to a control treatment (C) with no EG. Results of this research show that: a) both species are unable to survive if reared on a food substrate spiked with the highest concentration of EG (T3), while lower and medium concentrations (T1, T2) affect, but not prevent, the survival and the completion of the life cycle of such species; b) adults of L. sericata eclose only in C and T1, while adults of L. cuprina in both C, T1, T2; however, c) the developmental time of both species reared in T1 and T2 is statistically slower than the control; d) the body length of the immatures of both of the species reared in T1 and T2 is statistically smaller than the control

Development and validation of a GC–MS method for nicotine detection in Calliphora vomitoria (L.) (Diptera: Calliphoridae)

Entomotoxicology is the application of toxicological methods and analytical procedures on necrophagous insects feeding on decomposing tissues to detect drugs and other chemical components, and their mechanisms affecting insect development and morphology and modifying the methodology for estimation of minimum time since death. Nicotine is a readily available potent poison. Because of its criminal use, a gas chromatography-mass spectrometry (GC-MS) method for the detection of nicotine in Calliphora vomitoria L. (Diptera: Calliphoridae) was developed and validated. Furthermore, the effect of nicotine on the development, growth rate, and survival of this blowfly was studied. Larvae were reared on liver substrates homogeneously spiked with measured amounts of nicotine (2, 4, and 6 ng/mg) based on concentrations that are lethal to humans. The results demonstrated that (a) the GC-MS method can detect both nicotine and its metabolite cotinine in immature C. vomitoria; (b) the presence of nicotine in the aforementioned three concentrations in food substrates did not modify the developmental time of C. vomitoria; (c) during the pupation period, larvae exposed to nicotine died depending on the concentration of nicotine in the substrate; and (d) the resultant lengths of larvae and pupae exposed to 4 and 6 ng/mg concentrations of nicotine were significantly shorter than those of the control

Evaluation of Fenton and modified Fenton oxidation coupled with membrane distillation for produced water treatment: Benefits, challenges, and effluent toxicity

Membrane distillation is a promising technology to desalinate hypersaline produced waters. However, the organic content can foul and wet the membrane, while some fractions may pass into the distillate and impair its quality. In this study, the applicability of the traditional Fenton process was investigated and preliminarily optimized as a pre-treatment of a synthetic hypersaline produced water for the following step of membrane distillation. The Fenton process was also compared to a modified Fenton system, whereby safe iron ligands, i.e., ethylenediamine-N,N′-disuccinate and citrate, were used to overcome practical limitations of the traditional reaction. The oxidation pre-treatments achieved up to 55% removal of the dissolved organic carbon and almost complete degradation of the low molecular weight toxic organic contaminants. The pre-treatment steps did not improve the productivity of the membrane distillation process, but they allowed for obtaining a final effluent with significantly higher quality in terms of organic content and reduced Vibrio fischeri inhibition, with half maximal effective concentration (EC50) values up to 25 times those measured for the raw produced water. The addition of iron ligands during the oxidation step simplified the process, but resulted in an effluent of slightly lower quality in terms of toxicity compared to the use of traditional Fenton