Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Introduction: in the field of education, the use of models is becoming more frequent as an essential instrument to transform school practice and enrich its theoretical heritage. In the subject of Engineering and Software Management, it is essential because complex and extensive procedures are taught which are not always easily understood by the student; as a result the professors must assume new challenges in their teaching process. Objective: to design a didactic model for the improvement of the teaching-learning process of the Engineering and Software Management subject, facilitating to the students of the specialty of Information Systems in Health at Pinar del Río University of Medical Sciences, the application of contents associated with the design of software to the solution of professional problems. Method: this is a descriptive research; the theoretical methods were used as main procedures: historical-logical, analysis-synthesis, induction-deduction, modeling and systemic approach, within the empirical level the documentary analysis for the revision of the normative documents of this university study was applied. Results: a didactic model was achieved orienting the professors in the field of software design education, taking into account all the didactic components of the interdisciplinary and transdisciplinary process. Conclusion: this model has been structured by integrating motivation, content learning and the development of skills, values and qualities necessary for the professional training of professors of Informatics, taking advantage of the potential of Information and Communication Technologies. 

Common carp (Cyprinus carpio) is an aquatic organism of commercial value able to survive in polluted environments; carps contain proteolytic enzymes of physiological importance and potential industrial application. The objective of this work was partially purify and study the proteolytic activity at different pH of carp proteases living in a polluted environment. Three carps were captured in different zones of Zumpango polluted lagoon (Mexico) at 1 m of maximum deep. Protease crude extracts were obtained from dorsal muscle by aqueous extraction and fractionated by 20 %, 50 %, 80 %-saturated (NH4)2SO4. Fractions extracted with 50 % and 80 %-saturated (NH4)2SO4 were selected for their high proteolytic activity and concentrated by ultrafiltration through 100 kDa molecular weight cutoff membranes and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The crude proteolytic extract had significantly higher activity (19.7 - 20.3 U / mg) at pH 2, 5, and 7 (P < 0.001). Fractions obtained with 20 %, 50 % and 80 % - saturated (NH4)2SO4 showed peak activity at pH 5 (2.8 U / mg) and pH 6 (2.2 U / mg); pH 6 (4.3 U / mg) and pH 3 - 4 (3.6 - 3.7 U / mg); pH 3 (10.8 U / mg) and pH 10 (10.6 U / mg); respectively. Subfractions of < 100 kDa, obtained with 50 % and 80 %-saturated (NH4)2SO4, had peak proteolytic activity at alkaline pH. A < 100 kDa fraction, obtained with 80 %-saturated (NH4)2SO4, had the highest proteolytic activity (37.3 - 43.7 U / mg) at pH 8 - 10, purification factor of 3 and 19.1 % recovery. Thirteen proteins between 9.8 to 104.8 kDa were identified in the crude extract. Peak protein concentration was observed for 31 - 33 and 39 - 41 kDa, suggesting the possibility predominance of serine- and aspartyl- proteases, respectively. We suggest this protease with maximum activity at alkaline pH is related to the adaptation of C. carpio to polluted waters with high pH. Although unsuitable for human consumption, these organisms can be a source of protease production aimed to several uses as in the industry and waste water treatment among others.

Jatropha curcas is a native Mexican plant, distributed in the forests of coastal regions; it has shown potential for the production of biofuel, and its raw protein can be used as animal feed. Nevertheless, its current varieties have low yield and production variability, as it is in domestication period. The knowledge of the pollen grains is fundamental for studies of Jatropha reproductive biology and breeding for genetic improvement to generate new hybrids and improve fruit and seed yield. This study compared pollen morphology of four Jatropha species, which include two varieties of J. curcas (one toxic from India and one non-toxic from Mexico), and two varieties of wild J. cinerea (Sinaloa and Baja California Sur); additionally, pollen was collected from wild J. platyphylla (Sinaloa) and J. vernicosa (Baja California Sur) to characterize them palynologically. We used a scanning electron microscope to describe the size and shape of pollen grains. Pollen grains were observed spheroidal. The diameter of the varieties of toxic and non-toxic J. curcas and that of J. platyphylla were 58 ± 2.3, 54 ± 1.7, and 51 ± 2.4 µm, respectively; the number of clavae was 84 ± 10, 108 ± 15, and 180 ± 15.5, respectively. Pollen grains of J. cinerea (Sinaloa) had a diameter of 50 ± 1.7 µm and 220 ± 14 clavae by area; J. cinerea (Baja California Sur) had a diameter of 45 ± 1.9 µm and 195 ± 14.7 clavae. Pollen grains of J. vernicosa had a diameter of 46 ± 2.1 µm and 231 ± 25.6 clavae. The ornamentation of the exine showed clava with capita gemma shaped for varieties of J. curcas species and clavum shaped for J. platyphylla, J. cinerea and J. vernicosa species. The studied varieties have a cross-linked endexine and ectexine intectate. Luminal bacules were observed in the reticular space of J. curcas varieties while none were present in the varieties of J. cinerea, J. platyphylla, and J. vernicosa.

Dietary information gives insight into several ecological processes acting in lotic ecosystems. This work aimed: 1) to identify the dietary habits of Claudioperla tigrina immature stages along a wide altitudinal as well as latitudinal gradient in North Argentina; 2) to define the functional feeding group (FFG) of C. tigrina; 3) to evaluate differences in diet in the studied sites. Studied nymphs were collected from localities widely scattered in Northwestern Argentina and they fell into different developmental stages (four size classes). The ingested material was extracted from the foregut and midgut by using thorax ventral dissection. Dietary profiles were analyzed through the estimation of parameters associated with a Dirichlet-multinomial distribution. ANOVA’s were performed for each food item using sites as factor. Multidimensional Scaling was used to identify sites with similar dietary profiles. An analysis of food-niche breadth was also performed to evaluate the degree of dietary diversification for the resources consumed in each site. Mouthparts are similar across the different size classes, excepting the increasing sclerotization recorded with age. Mouthparts retained most of the typical chewing groundplan, showing relatively short labial and maxillar palps, and strong, sclerotized and denticulated mandibles and maxillae. Our results pointed out that the nymphs of C. tigrina always ingest two or more food items (CPOM, FPOM, invertebrates and algae), suggesting thus a flexible diet. The diet changed in relation to body size, while finer particles were consumed in the early stages, larger particles were ingested in final stages. Coarse particulate organic matter was the dominant food item, with signals of shredding during ingestion. Differences between sites for FPOM, invertebrates, algae and sediment were detected, but not for MOPG. Correlations were obtained for the first two axis of the MDS analysis. Sites AP, LT, LI, C and M (Yungas Rainforest and Humid Grassland) were negatively correlated with the axis 1 which was associated with increased consumption of FPOM. On the positive side of the axis the site P (High Andes) is associated with a greater proportion of invertebrates and sediment. The sites IN (Humid Grassland) and LR (Argentine Northwest Monte and Thistle of the Prepuna) were located at the positive domain of axis 2 which is in turn associated with a greater count of algae in the dietary contents. We found significant differences in the quantity of secondary items, and this is likely related with the resources environmental availability. The FFG of Claudioperla tigrina is primarily shredder/collector-gatherer in Yungas Rainforest and Humid Grassland shredder/predator in High Andes. FFG classification of C. tigrina and the definition of their role for organic matter processing is an important step for future studies based on functional groups such as analysis of food webs.

Functional morphology corresponds to adaptive responses to changes in the environment. In phytoplankton, traits such as the development of mucilage, oil vesicles, filaments and variation in the surface/volume ratio, allow algae to deal with sedimentation, optimizing light and nutrient uptake. The aim of this research was to evaluate the relationship between traits and variation in physical and chemical conditions in Tota Lake (Boyacá, Colombia). For this, ten samplings were undertaken in a monthly basis between October 2013 and July 2014. We measured water pH, conductivity, temperature, dissolved oxygen, oxygen saturation, alkalinity and total hardness; we also quantified Total Kjeldahl nitrogen and Total phosphorus. Algae were collected at different depths according to Secchi transparency. Taxonomic composition and abundance were estimated by the chamber sedimentation method. Morphological traits were measured for each taxa according to geometric models, allowing traits classification into morphologically based functional groups (MBFG) and having algae biomass expressed as biovolume. The variables were evaluated through Principal Components Analysis, which included time-space effect and it was interpreted according to variation in water level. Through Canonical Correspondence Analysis we established the relationship between phytoplankton biovolume accumulated in form categories and environmental variables. The ordination showed that limnological conditions are influenced by seasonal changes, which are mainly represented by oxygen saturation percentage, Secchi transparency, TKN, hardness and alkalinity. Four MBFG were found: IV, V, VI and VII, being MBFG IV and VII the most representatives. ACC was significant (Monte-Carlo Test, p<0.05). In conclusion, the morphological and functional response of phytoplankton in Tota Lake is driven by short-term variability in transparency, phosphorus, nitrogen, hardness, and electrical conductivity, which are all affected by seasonal changes in the lake level.

In fishes, gonad morphology is an important parameter to understand the reproductive biology, phylogenetic relationships and systematic studies. The main objective of this study was to make a comparative analysis of the morphology of mature ovary and testis in six fish species of the family Anostomidae. A total of 212 specimens, presenting maturing gonads, were captured from the São Francisco River, Três Marias Reservoir area, in Southeastern Brazil, between August 2008 and December 2010. The six analyzed species had mature ovaries and showed a grayish color. In vitellogenic oocytes (VO), cortical alveoli (CA) were composed by small vesicles in all Leporinus species, but in Leporellus vittatus and Schizodon knerii the CA were large vesicles. However, the CA of all species showed similar histochemical content. The pellucid zone consists of two layers to all species, but it was thicker in S. knerii (11.5 ± 1.8 µm) than in L. vittatus (9.0 ± 0.8 µm) and Leporinus species (3.5 ± 0.6 - 8.7 ± 0.9 µm). Follicular cells of the VO were respectively cubic and prismatic in animal and vegetative poles of S. knerii (22.3 ± 3.2 and 61.1 ± 9.6 µm), and squamous in the other species (1.3 ± 0.3 - 1.6 ± 0.3 µm). Females of S. knerii and males of L. vittatus showed lower values of gonadosomatic index (GSI) than the other assessed species. All evaluated species presented testicular morphology similar to most neotropical Characiformes, with unrestricted spermatogonial testis and anastomosing tubular organization of seminiferous tubules. Phenotypical differences in the vitellogenic oocyte of Anostomidae fishes, confirmed the taxonomic position of S. knerii as different genus in relation to Leporinus and L. vittatus. Despite being placed in different genera, the characteristics of the vitellogenic oocytes of L. vittatus were similar to those found in the studied Leporinus.

Oil exploitation and the usage of its derivatives have undeniably contributed to the technological advance worldwide. This industrial activity, however, generates several by-products that can threaten environmental sustainability. Seawage, for example, can contain organic pollutants and heavy metals; therefore, its deposition must be preceded by adequate water treatment. In this study, we isolated, characterized, and molecularly identified eight bacteria on the basis of their capability to degrade phenol. First, we determined the rates of bacterial growth and phenol degradation using different concentrations of the aromatic hydrocarbon (500, 800 and 1 200 mg / L), and then used sequential statistical designs to select optimal conditions for its degradation. Results showed that all isolated strains were capable of degrading phenol as the sole carbon source; the degradation kinetics and phenol tolerance, however, widely varied among strains. We chose the strain Pseudomonas sp. Sps1 for further studies due to its remarkable tolerance and capability to degrade phenol. By using a Plackett Burman design, followed by a fractionated factorial design in which several carbon, nitrogen, and phosphorus sources were evaluated, and phenol degradation was used as the response variable, we found optimal conditions for phenol degradation by Sps1. Finally, we compared phenol degradation in seawage by the use or not of the optimal conditions established by the statistical methods. Results showed that biostimulation dramatically increased phenol degradation compared with the control. In conclusion, we found that bioaugmentation with the native bacteria Sps1 and a statistically-based biostimulation approach provided an economically and environmentally friendly alternative for the removal of pollutants from oil industry sewage.

Nicaragua is a small country in Central America and little has been published about its scientific output. Most of its publications available in international databases are about medicine and are produced by Universidad Nacional Autónoma de Nicaragua (Managua) as part of international collaborative teams. In this article we analyzed in more depth, and for a longer period than any previous study, the presence of Nicaraguan publications in the Science Citation Index Expanded until January, 2016. In total, 837 Nicaraguan articles were published in 456 journals (the top journal is the American Journal of Tropical Medicine and Hygiene). Internationally collaborative articles with 94 countries accounted for 92 % of articles, while only 8.5 % were exclusively Nicaraguan. The most cited article described the use of ketoconazole to treat Leishmaniasis. The authors with more publications in the database were A. Balmaseda, R. Peña, W. Strauch, and F. Bucardo. The top cited, exclusively Nicaraguan articles dealt with health problems, forest tenure, and food production. The article citation lifespan is surprisingly long: over 70 years. Most citations start seven years after publication and are not recorded by the Science Citation Index, which for that reason cannot be considered valid to evaluate the impact of Nicaraguan research. The predominance of English publications may reflect a bias of the database itself. Probably most of the scientific production of Nicaraguan scientists is published in Spanish, in many regional journals not included in the SCI-EXPANDED. Nicaraguan research centers lack appropriate infrastructure, staffing and financial resources: future achievements for Nicaraguan science should include a fair presence of female researchers, peer-to-peer level participation in international teams, and less dominance of health technologies.

The present paper describes part of an ongoing process of innovation which started in 2009 of both the current curriculum and the assesment practices of the Music Department (DMUS) of the Faculty of Arts at the University of Chile. I identify some of the most important critical points that have emerged from the analysis of the current practices of the DMUS academic programs of musical performance, along with the teachers’s representations of the musical learning evaluation. The problems are similar to those of other university institutions that started in a conservatory cultural system. The educational current model of the DMUS is partly described on the basis of two aspects that I consider relevant: previous experiences and the assessment criteria. I focus on these aspects because of the complexity evinced at different periods of time, both in our institution and elsewhere in similar institutions, and on account of the interest they have aroused in different instances of socializaton. Finally, I propose some elements and viewpoints concerning the music learning process, which I hope can contribute to improve the understanding of these practices, particularly among those teachers and students that are participating in processes of curricular innovation of music academic programs.