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In this paper, the study of Cuban zeolite to determine the possibility to use it in management of liquid radioactive waste of low activity has been performed. Some sorption characteristics of this material with Cs+, Sr2+ and Co2+ has been determined using radioactive indicator methods. [ABSTRACT FROM AUTHOR]

The review paper presents national experience in the formation of a scientific interdisciplinary colective of nuclear physicists, engineers and other specialists as essential part of the infrastructure for an indigenous nuclear power program. The need of efforts aimed at nuclear data activities and fission studies is emphasized. The main scientific results obtained in this field and in the development of nuclear physics with neutrons arc summarized. The are mainly related to the investigation of low energy neutron inelastic scattering and the development and improvements of modern statistical theories of nuclear reactions. Also as a point of great interest, works on applied nuclear physics and nuclear data measurement and compilation are included. [ABSTRACT FROM AUTHOR]

This paper examines the main steps of the noise analysis technique implementation in our country from 1988. The review identifies two main areas: improvements of nuclear power plant operational surveillance techniques and non-nuclear industrial application. Some of the on-going research programs including projects on noise analysis instrumentation developments at the Higher Institute for Nuclear Sciences and Technology are also reported. [ABSTRACT FROM AUTHOR]

The paper shows the main results obtained in the studies of the ambient radioactive background carried out in the future site of nuclear installations: the Nuclear Research Center La Quebrada, Juraguá nuclear power plant and the northern part of Holguín. The materials and methods used for the work are the recommended by the Center of Radiation Protection and Hygiene and are accepted internationally. From the results obtained, we conclude that dose rate levels due to gamma radiation, as well as natural radionuclide concentrations in different objects of the environment and in foodstuffs within the zones of interest are consistent with those reported in literature for regions without anomalies. The evaluations of the committed effective dose due to the intake of Sr-90 per milk consumption in a year and the external irradiation due to the exposition to Cs-137 existing in soils, gave values between 0.1 and 1.3 µSv for the first and less than 1 µSv/year for the second. [ABSTRACT FROM AUTHOR]

The paper describes the main characteristics of the several software developed in the Higher Institute of Nuclear Sciencies and Technology directed to personnel qualification and probabilistic safety analysis. In adition, the paper shows some of the main results of its applications to the national industry. [ABSTRACT FROM AUTHOR]

The paper shows the most significant issues, resulting from the analysis based on instantaneous reliability versus the traditional mean reliability calculations, as well as other important applications related to the safe operation of Juraguá nuclear power plant. [ABSTRACT FROM AUTHOR]

This paper reports the concentrations of 30 elements (major, minor and trace elements) in four Cuban samples. The samples were irradiated in a thermal neutron flux of 1012-1013 n.cm².s-1. The gamma-ray spectra were measured by high purity germanium detectors and were analyzed using ACTAN program developed in Center of Applies Studies for Nuclear Development. [ABSTRACT FROM AUTHOR]

An explosive increase of the antropogenic river contamination is the result of population and industries griwth and also had important contribution the indiscrimanate use of synthetic products. This situation is for Cuba, a narrow and long island with limited hydraulic resources, a very alarming problem. In this paper Los Guaos River water quality, whose end is the Santiago de Cuba's bay, was studied. Monthly, in the February-April period, using six sampling stations, 22 physical, chemistry and bacteriologic parameters were determined. This information brought that this river in its complete length is highly contaminated and then its water is invalidated for supply. [ABSTRACT FROM AUTHOR]

In this paper it is presented a number of advantages brought about by the predictive maintenance system in the sugar mill "Carlos Caraballo" in Ranchuelo, Villa Clara, Cuba. It is also explained the influence exerted by the system on the reduction of the percentages of time wasted because of industrial breakdowns, maintenance and cleaning, as well as the reduction of consumed products. [ABSTRACT FROM AUTHOR]

Two models for the determination of the residence time of the clarifiers with central feed are presented in this paper, but in this case the extractions of juice are taken into account. Two illustrative examples are presented. [ABSTRACT FROM AUTHOR]

A review the principles by optimization of refining operations of bagasse pulp in disk refiners are discussed in this paper. These principles are used to research the semichemical and bleached chemical bagasse pulps from Cuba's Paper Industries. The best results were obtained with cutting angle from 70° grad and low level of specific edge load (0.75 N) and specific energy consumption (100 kWh/t). [ABSTRACT FROM AUTHOR]

The mountains of Sierra del Rosario, in the Western of Cuba, are a key area for the knowledge of the geology of Cuba. Five distinct sequences are present: 1. Middle to Upper Jurassic (Oxfordian), 2. Middle Oxfordian-Cenomanian (locally Turonian?), 3. Campanian, 4. Upper Maastrichtian (or K/T boundary), 5. Upper Paleocene-Lower Eocene. The two first are rich in organic matter and were settled in anoxic bottoms. Sequences 3, and specially 4, are the record of brief sedimentary episodes in non depositional times; sequence 4 is possibly an instantaneous K/ T boundary deposit. The mesozoic rocks were accumulated in the passive continental margin of North America. The Upper Paleocene-Lower Eocene beds are mainly the chaotic sediments of a foredeep, where Sierra del Rosario nappes were piling. The nappes are the most striking element in Sierra del Rosario tectonics, with thrust planes related to particular stratigraphic levels. Therefore, each nappe packet has its own stratigraphy, and five great packets can be distinguished. The layer thickness and the number of shaly interbeds control the degree of dislocation. Melanges play a leading role in Sierra del Rosario tectonics. The stratigraphy and tectonic position of Sierra del Rosario are very similar to those of Placetas zone, in the central part of Cuba, where the main cuban oil deposits are located. This important fact for the search of oil and gas in western Cuba is discussed in the paper. [ABSTRACT FROM AUTHOR]

The set of tectonostratigraphic units that conform the actual geology of the Island of Cuba; they make it distinctive from the rest of the Greater Antilles islands. The Cuban folding belt extended in the western and central part of the country, fundamentally characterized by the presence of rocks of an arc of volcanic islands of Cretaceous age, plus an ophiolitic crust, that rides over the carbonatatedterrigene and carbonatated sequences of an ancient continental margin of Jurassic- Cretaceous age. In this paper the objectives are: 1) an evaluation of the tectonostratigraphic systematization used in Cuba and some critical ideas on the same; 2) a tectonostratigraphic systematization is proposed for the eastern center sector of Cuba, defined by the system of Trocha Fault in its western part and Cauto-Nipe fault to the east. This is carried out according to the conceptions of Formational Structure Associations (FSA). The systematization on base of the FSA, present great advantages, well it permits a better understanding of the geologic evolution of a territory and of the cuban fold belt Cuban in particular. For which, we defined, into the eastern center portion, the following FSA. • Southern paleomargin of North America. • Cretaceous volcanic island arc. • Ophiolites of the suprasubduction Cretaceous zone. • Southeastern paleomargin of Yucatan Block. • Cretaceous volcanic island arc. • Neoplataformic. [ABSTRACT FROM AUTHOR]

Among the most important natural resources, and contradictory the less abundant, the water occupies the first place for being it a source of life. Its conservation and preservation is of a great importance for humanity. The phenomenon of sea water encroachment, common in karstic aquifers, intensifies naturally or artificially according to the precipitation regime, an unbalanced relationship between precipitation and recharge or because the human activity causing the loss of the natural water quality. It is of a great interest the study of this process with the purpose of its better understanding. Guane Watershed is located in the Western part of Cuba and occupies an area of 1 253 km². It has a certain degree of salinization from the hydrogeological point of view with a variable behaviour in the mix zone. New reported data about redox potential and dissolved oxygen is also presented in this paper. [ABSTRACT FROM AUTHOR]

When it is necessary to determine the susceptibility of Neisseria meningitidis (Nm) strains to antimicrobial drugs, it is important to consider that it should be analyzed in a double context. One of them related to the use of drugs in a specific medical treatment; and the other; to chemoprophylatic drugs, both with the same purpose: the accurate selection of the "in vivo" antimicrobial agent. This requires the study of the sensitivity and resistance of strains isolated in both carriers and patients. With the aim of further studying the behavior of the strains that currently circulate in Cuba, an antimicrobial drug susceptibility study was conducted in 90 strains isolated from carriers during the first half of 1998. The agar dilution method was used to determine the minimum inhibitory concentrations (MICs) to: penicillin, ampicillin, rifampin, sulfadiazine, chloramphenicol, ciprofloxacin, ceftriaxone, cefotaxime. The study of the three latter drugs was done for the first time in our country. The search for β-lactamase-producer strains was also performed. There was a predominance of penicillin sensitive strains (82,2%) with an intermediate sensitivity to ampicillin (57,8%), while 70% of the strains were sensitive to sulfadiazine. Regarding the rest of the antimicrobial drugs, 100% of the strains were sensitive. The paper shows the MICs for each drug as well as the phenotypic characteristics of the strains with the penicillin and sulfadiazine sensitivity and resistance patterns. No β-lactamase-producer strains were found. [ABSTRACT FROM AUTHOR]

The Chemistry in Cuba started at the beginning of the last century, involving fields like medicine and sugar cane industry. The chemical activities were associated with the names of Félix Varela, José A. Saco, José de la Luz y Caballero, José Casaseca and Álvaro Reynoso. In this paper an historical view of the Chemistry in Cuba since 1814 when the first cuban chemist Estevez y Cantal, analyzed the Ugalde¨s pill until nowadays is exposed. [ABSTRACT FROM AUTHOR]

The following paper includes the description of the design, construction and completion of a data acquisition system. The system is destined to the sampling of the work parameters of the generator of microwaves of the microtron MT-25 that will settle in the High Institute of Nuclear Sciences and Technology, Havana, Cuba. In order to guarantee the suitable operation of the system a monitor program in assembler language has been developed. This program allows the communication of the system with one personal computer through the interface RS-232, as well as executes the commands received through it. Also the development of a program of attention to the. system from one personal computer using the methods of the virtual instrumentation is included in this paper. [ABSTRACT FROM AUTHOR]

In this paper are explained the basics principles to keep in mind upon defining any procedure in order to determine a rational mesh to obtain samples, in order to carry out the exploration of the laterite deposits from Cuba. These principles part from the characteristics of the parameters that are studied (in particular the variability), the unit between the level of the knowledge to we are aspired, and the model that is employed in order to represent and study the behavior of these parameters. The necessity of modeling panels on supports of ó blocks is accentuated instead of making it on punctual supports as well as the convenience of using regular mesh. [ABSTRACT FROM AUTHOR]

There is a great diversity of gold-bearing deposits and mineral manifestations in Cuba, but, there is not yet, among the other aspects of interest, a classification that takes into consideration the kind of deposits and its different styles, the specific feature of the geological areas, the particular characteristics of mineralization, the types of accompanying attention and the geoquemical and mineralogical indicators. In this paper it is proposed a classification for Cuban gold-bearing deposits that takes as reference the classification made by Corbett and Leach (1995) in which criteria of many authors have been integrated. Special attention is devoted to districts, poorly studied and characterized by a particular gold-bearing mineralization, like Santa Clara, Holguín and Sagua-Baracoa districs. They have been developed fundamentally in geological environment characterized by the presence of complexes of ofiolítico association. [ABSTRACT FROM AUTHOR]

The Cuban sugar season takes place during a few months in the year. One of the most important points observed during its scheduling is its time length. Usually the season length depends upon the availability of planted sugar canes, the industrial capacity and avoiding the spring rains time. Other aspect that may be used for a better argumentation to the sugar season length is the cost related to reliability maintenance of the industrial machinery. This paper develops an optimization procedure in order to find an optimal season length when reliability maintenance costs are minimal. [ABSTRACT FROM AUTHOR]

The objective of this paper is to show a methodology that allows finding the optimal behavior of a system, given a measure of effectiveness and a set of controllable variables. In the paper simulation techniques are combined with experimental design to produce a response surface, and after an optimization method is applied. A case study in the Cuban sugar industry is described. [ABSTRACT FROM AUTHOR]

In this paper it is presented a methodology for the minimization of residuals and industrial emissions, which is a guide for the environmental work developed in the Biotechnology Department of the Solar Energy Research Center. The paper presents the advantages of the preventive solutions for the industry. The techniques used for the pollution minimization in the industry, as well as an example of applications in the Caney factory in Santiago de Cuba are also presented. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present an analysis of Water Magnetically Treated (WMT), and its effect in a sample of the boilers of the Sector of Public Heatlh of Santiago de Cuba province. Some important recommendations are given for the right selection and installation of the magnetizer equipment, so as to guarantee the correct functioning, and an analysis of the benefits obtained in three years of work in ten low pressure boilers of Public Health, in the province of Santiago de Cuba. [ABSTRACT FROM AUTHOR]

This paper proposes a new organization of the maintenance work in the Cuban sugar mills, as a way to increase the productivity, quality and decrease of the cost of production of sugar, so as to improve the competitive position of this traditional Cuban industry in the international market. The management in maintenance implies the full development of the implicit functions of the activity and the improvement of daily indicators, through the introduction of new technical, organizational and economic concepts in order to lower the costs of the activity and to increase the industrial availability. This organizational work has been partially introduced at Fernando de Dios Sugar Mills in Holguín, where technical an economical benefits of its application has been demonstrated. In the comparative analysis of the three last years carried out in the sugar mills above mentioned, The Management Maintenance System (MMS) proposed proved efficient as opposed to the current management maintenance system. The organization proposed brought about the improvement of management maintenance profitability in a 20,12%. [ABSTRACT FROM AUTHOR]

The critics of knowledge management, consider as not justified, the attention that is given to this activity. On the contrary, its supporters consider this attention, insufficient. Nevertheless, existing literature on this matter is more prolific in theoretical approaches, than in practical applications. This means that the biggest part of non specialized organizations in this matter, are facing difficulties regarding the application of knowledge management. Besides, in no few occasions, the application of knowledge management is separated from the application of information management. Is for this reason that, this paper offers a group of general recommendations for the introduction of information management and knowledge management in Cuban organizations. Are given the general characteristics and requirements that such strategy must have: wide scope, be able to integrate, basic, dynamic, open and whit a vision of future. Are also given the principles in which should be based this strategy, as well as, its objectives and general actions to be taken. It is included why it is convenient to have a pilot plan and are given the characteristics that should have this type of plan. [ABSTRACT FROM AUTHOR]

In this paper is questioned why is so limited the offering of consulting services by Cuban information organizations, taking in account that is in these organizations where exists the greater human capital that can offer these services. Are analyzed the perspectives of this service in Cuban information organizations and are given some the different approaches that they should analyzed, in order to offer this service, taking in account the characteristics of that marketplace. Herein is highlighted the importance of the marketing plan, as a tool for the strategic management, in order to choose the better ways to reach this objective. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the discourse of the current president of Venezuela, Hugo Chavez during the 1998 electoral campaign and the first year of his government. Discourse is analyzed from the dual-perspective pragmatic/semantic focus. In the semantic component, the characteristics of the leader are configured in the form of political and social knowledge, presented in a narration constructed from the personal point of view (first person) of the speaker according to the persuasive finality of the political discourse. Here, Chavez' authoritarianism is visible and characterized both as a leader of military origin who emerges on the Venezuelan political scenario during a military coup, and also due to his own discourse style. This analysis is situated in the political, historic and social context that occurred before the electoral victory of President Chavez in the elections of 1998. [ABSTRACT FROM AUTHOR]

Up today they are 22 valid species of the genus Bemlos in the Western North Atlantic Region. Of these, 9 are already recorded from the Cuban Archipelago. The amphipod crustacean Bemlos rolani, new species, which was caught by the First Cuban-Spaniard joint Expedition on board of the R/V "Felipe Poey", in 1994, when collecting on Thalassia beds, at the South Western Cuban Platform, is herein described. The main differences among B. rolani n. sp., and B. kunkelae (Myers, 1977), B. dentischium (Myers, 1977), and all other species of the genus, in the region, except those considered in the paper published by Myers (1981), are also given. [ABSTRACT FROM AUTHOR]

In the paper, a study about the use of possibilities of a new type emulsifyng agent obtained from pyrolyisis products of lignocellulosic materials, with Cuban crude petroleum for the preparation of emulsioned paints is presented. The viscosity reduction, the improvement in the handling and the use of obtained emulsions as substitute of asphaltic paints are informed. It is proved that may be obtained direct emulsions with Cuban crude petroleum concentrations of 50-60 % wt., using 3 % wt. concentration of emulgent P (here it is called emulsifyng agent) respect to water. The emulsion characteristics are mantain similar to others prepared with tensioactive agents commonly used. [ABSTRACT FROM AUTHOR]

The availability of productive resources is one of the basic dimensions of quality. The improvement of the reliability is one of the main strategic objectives of any industrial organization. In this paper a procedure will be described to activate the improvement of the reliability of industrial equipment in order to develop the information infrastructure according to the existing database. An advanced software system for this field of knowledge will be used, and thus a contribution is expected in this sense. The application of the proposed procedure was accomplished in a Cuban industrial organization. [ABSTRACT FROM AUTHOR]

The synthesis of the Catalogue of Perceptible Earthquakes from 1528 to 1990, which have been obtained and elaborated to be used at the same time as a Data Base in a PC, is presented. Although usually, the periods of time which are used in seismic analysis are limited due to the lack of instrumental information, this Catalogue contain the enough amount of information to allow the extension of that periods of time. As a complement of the Catalogue, examples from the Atlas of Isoseismal Maps of Perceptible Earthquakes which epicenter located in Cuba, was also finished. The last one is fundamental for the characterization of Seismic Attenuation in Cuba in terms of intensity, for Seismic Hazard assessment. The temporal-spatial analysis of the perceptible earthquakes permit us to evaluate the Seismogenic Zones from the Seismotectonic point of view. Furthermore a theoretic-experimental analysis of the Attenuation's Law of Seismic Intensity from Greater Antilles, and the main parameters associated to Seismogenic Zones of Cuba, is showed. These ones were obtained from Isoseismal Maps of perceptible and large earthquakes. The results obtained from the probabilistic and deterministic Seismic Hazard Assessment, for different regions all over the country, have been unified in this paper. From the Seismic Hazard Map resulting, the Seismic Zonation Map with Engineering Purposes was also obtained; the last one was proposed for the New Seismic Cuban Design Code. As a contribution to the characterization of Cuban Seismicity an spatial -- temporary -- energetic analysis of the perceptible aftershocks was made, including their relation with our Seismogenic Zones, obtaining an empirical relationship between the Length of Rupture and the Magnitude values, estimated by Macroseismic Data. [ABSTRACT FROM AUTHOR]

In the present paper, five white shrimp Litopenaeus schmitti populations of South Cuban Coast, were genetically characterized using 21 electrophoretic loci derived from 9 protein systems. The most variable population was the one from Tunas de Zaza (He= 0.132) and while the less variables were the two from Guacanayabo Gulf (He= 0.078 and 0.087). Calculated mean genetic distance was 0.019, and the smaller genetic distance value was found between Batabanó and Guacanayabo Gulfs, which is discordant with their geographic location, marine currents and the cycle of life of the species. [ABSTRACT FROM AUTHOR]

Havana's "ciudadela" is a particular example of tenement house built for rent to very poor people. There have been a great amount of them along 19th and 20th Centuries, as the city sprawled as a consequence of economical facts. In this issue, three papers, conceived as an unity explain "ciudadela" from different points of view: history of the architectural type, showing parallelism with examples from other countries; characterization of the type and those transformations made by inhabitants. And, last, "ciudadela's" values are analyzed in order to show its cultural significance. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to provoke a discussion about the role of education in the promotion of the real learning that will serve people to face the changes required for a future society. It is showed briefly the program for the "Formation of Self regulated Apprentices in Learning Communities ", created by the authors as apart of their research, in the Center for Psychological and Sociological Research of the Ministry of Science. Technology and Environment of Cuba, to provide an answer to this social demand. It shows too theirs experiences in teaching some mexicans professors in the state of Morelos who have now the opportunity to implement in theirs schools the pedagogical model presented in the program. [ABSTRACT FROM AUTHOR]

The consumption of lime in the Cuban sugar industry doesn't follow the well-known patterns. To illustrate such a behavior, in this paper is presented a study of a case of the consumption of lime in the sugar factories of the province of Cienfuegos. In this work is carried out an analysis of the causes that motivate this anomalous behavior, and solutions are proposed. [ABSTRACT FROM AUTHOR]

In this paper is shown a procedure to define the strategy for achieving the program of development of the agricultural production of the Sugar Cane Ministry in Villa Clara province, in a consultative and participative way at a productive level. This is part of the national program Álvaro Reynoso, taking into consideration the restructuring of the Cuban Sugar Cane Industry. [ABSTRACT FROM AUTHOR]

Main economic and environmental aspects of cogeneration technologies for the energy sector of sugar cane industry are considered in this paper. Special emphasis has been made about the aspects of the fuel cycle affecting environmental performance of these technologies. An assessment is done to show the potential of sugar cane biomass in the context of the Cuban energy sector. [ABSTRACT FROM AUTHOR]

The results of the chemical characterization of Gracilaria blodgettii in Cienfuegos Bay are discussed in this paper, with the purpose of contributing to the knowledge of this resource for its sustained exploitation. There were studied different variables in this species, such as yield and quality of agar, composition of metabolites and nutritional components, in the period from 1993 to 1999. The concentration of agar extracted shows a seasonal behavior, corresponding the highest values to the period from November to April; its quality can be classified like commercial agar "class B", which could be used in the food industry and in the production of in vitro plants. The results of the chemical screening of this algae show the presence of metabolites, such as: amino acids, triterpens and/or steroids, phenolic compounds and/or tannins, reducing sugar, lactons and saponins that, linked to the compounds identified in the bromatologic study (proteins, carbohydrates, fibers and minerals), confirm the nutritional, pharmacological and biomedical values of the components of this seaweed. [ABSTRACT FROM AUTHOR]

San Isidro de los Destiladeros, is one of the 73 architectural and archaeological sites of the Valle de los Ingenios. It was declared Cultural Patrimony of the Humanity in 1988. At the moment it is an study object, because constitute one of the most complete that exists, and it allows, in spite of the step of the time and their high grade of deterioration, a quite eloquent reading of their past. This paper analyzes their values and the rescue works, conservation and patronage search, carried out to rescue an unique place of the Cuban geography. [ABSTRACT FROM AUTHOR]

The rural housing is analyzed in Cuba, valuing the topic of the sustainable development in its different dimensions. The solutions that think about have like mark the purpose of diminishing the traditional differences between city and field, as well as the paper that its carry out the rural establishments in the production of foods and the use of the renewable sources of energy. [ABSTRACT FROM AUTHOR]

The correct administration to a patient of the a priori established activity of the radiopharmaceutical is an important factor to ensure the confidence in the diagnosis or the therapy efficiency, keeping at the same time the human exposure as low as possible. National comparisons for the 131I, 201Tl and 99mTc activity measurements in activimeters have been organized for the first time with the aim of obtaining information about the quality of the administration of radiopharmaceuticals. The comparison results, shown in this paper, have facilitated the identification of the problems and to initiate preventive actions. Furthermore, these results reflect the need of establishing Quality Systems in Nuclear Medicine in Cuba. [ABSTRACT FROM AUTHOR]

The paper represents a hydrogeologic regionalization of Pinar del Río province in GIS platform. The principles of elaboration of this map propose the division of the territory starting from the automatic integration of a group of such natural variables as: physical-geographical characteristics, hydrology, geomorphology, hydrogeology and structure particularities. It is recognized the regional regularities and the common features of each hydrogeologic structure, such as: the sources of the underground waters, the recharge conditions, circulation and discharges of the horizons and aquifer complexes, hydrochemical and hydrodynamic zoning. [ABSTRACT FROM AUTHOR]

This paper includes results of the research works on the direct (O/W) emulsion preparations of the Cuban crude petroleum, using pyrolysis products as emulsifier agent. Rheological characterization of the emulsions, immediately after their preparation and inside of some storage time is informed, so as some considerations about piping transport of these emulsions are reported. [ABSTRACT FROM AUTHOR]

The present paper carry on a general outlook about the sugar world production in the second half of the XX century, mainly about the sugar production in Cuba during the same period. In the article are analyzing too the sugar world exportations like the Cubans, showing the figures of the main exporter countries. It show the future sugar production & exportation outlook and the competition in the international marker of sugar versus products for edulcoration. Finally, the paper refer the prices evolution in the international market and its different levels and forecast of possible trends. [ABSTRACT FROM AUTHOR]

This paper tries about the development the sprinkler irrigation of low intensity in the Cuban agriculture, in which the reason of the rescued of this irrigation technique is based, under the current conditions and that it motivated this new re-election. They are given, also, to know the historical antecedents of the development of this technology in Cuba where this system is characterized in its different variants. With the world development of the sprinkler irrigation plastics systems our country has advanced also. For that reason, the new focuses of the portable sprinkler of low intensity, and the future lines of work, are exposed. [ABSTRACT FROM AUTHOR]

Sexual education programs actually insist in working with parents. This paper comments some recent experience, its theoretical basis and the related research. Cuban research in this field began with descriptive studies about parents' knowledge, attitudes, and behaviors. Research designs were also employed to study the effects of some sexual education programs. Action Research and Participative Research are, currently, the most common. The paper analyzes the design of the evaluative research of the project for Sexual Education of the Cuban Ministry of Education. [ABSTRACT FROM AUTHOR]

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At the present paper I expose briefly the scientific work of the Dr. Diego Gonzalez Martin who was the initiator in Cuba, in the decade of 50 in the XX century, of a new scientific approach in psychiatry, psychology and neurophysiology based on the Marxist theory and that, as researcher, he reached national and international recognition. [ABSTRACT FROM AUTHOR]

In this paper the author presents the results obtained from an exploratory and comparative study on the application of two different ways of structuring the mathematical content in the B.S. program of Agronomy Engineering at the University of Guantanamo. The compared forms were: one consistent with the formal systematization of the exposition of the knowledge already obtained, and the other one based on problem solving. In the verification of the hypothesis the sign test was used. Preliminary results showed that the variant of systemic structuring of knowledge by means of problems has greater effects in the efficiency of the knowledge acquired by the students than the one gained by means of the logic of the exposition of the obtained knowledge. [ABSTRACT FROM AUTHOR]