Information science research via graduate education in Cuba up to the year 2010

Los estudios de posgraduación en cualquier campo del conocimiento suponen un elevado nivel de especialización en los resultados de investigación. Conocer la evolución de la producción investigadora a través de parámetros empleados en la evaluación de la ciencia, como los indicadores bibliométricos, adquiere, por tanto, relevancia cuando los datos que se analizan provienen de estudios de este tipo. En este artículo se analiza el caso de la investigación posgraduada en el campo de la información en Cuba y se ofrecen resultados a través del análisis de indicadores, como la cantidad de tesis defendidas por año y grado, los tutores más productivos, la colaboración en la tutoría, el comportamiento de estas investigaciones por línea de investigación, así como los tópicos más estudiados y los tipos de investigación predominantes en el campo. También se analiza la filiación institucional y geográfica de los graduados. Del total de 156 tesis, 35 son de doctorado y 121 de maestría. Los tutores más representados son figuras prestigiosas de la especialidad; la línea de investigación más tratada es la relacionada con la gestión documental, de información y del conocimiento y la mayor parte de las investigaciones (71 %) son de carácter empírico. La mayor parte de los egresados de programas de posgrado en la especialidad pertenecen al Ministerio de Educación Superior y se concentran mayoritariamente en la capital del país.Graduate studies in any area of knowledge presuppose a high level of specialization in research results. Understanding the evolution of research production usingscience evaluation parameters such as bibliometric indicators, is even more relevant when the data under analysis come from this type of study. The paper examines the status of graduate research in the field of information science in Cuba. The results provided are based on the analysis of indicators such as the number of theses submitted per year and degree, the most productive supervisors, the number of joint supervisions, the behavior of research tasks per research line, the topics most frequently dealt with, and the predominant research types in the field. An analysis is also conducted of the institutional affiliation and geographic location of graduates. Of the total 156 theses, 35 are doctoral and 121 correspond to the master's degree. The most represented supervisors are prestigious professionals from the specialty. The most common research line was document, information and knowledge management, and most studies (71%) were empirical. Most participants in graduate programs from the specialty belong to the Ministry of Higher Education and most of them live in the country's capital

Growth of vertically aligned ZnO nanorods using textured ZnO films

A hydrothermal method to grow vertical-aligned ZnO nanorod arrays on ZnO films obtained by atomic layer deposition (ALD) is presented. The growth of ZnO nanorods is studied as function of the crystallographic orientation of the ZnO films deposited on silicon (100) substrates. Different thicknesses of ZnO films around 40 to 180 nm were obtained and characterized before carrying out the growth process by hydrothermal methods. A textured ZnO layer with preferential direction in the normal c-axes is formed on substrates by the decomposition of diethylzinc to provide nucleation sites for vertical nanorod growth. Crystallographic orientation of the ZnO nanorods and ZnO-ALD films was determined by X-ray diffraction analysis. Composition, morphologies, length, size, and diameter of the nanorods were studied using a scanning electron microscope and energy dispersed x-ray spectroscopy analyses. In this work, it is demonstrated that crystallinity of the ZnO-ALD films plays an important role in the vertical-aligned ZnO nanorod growth. The nanorod arrays synthesized in solution had a diameter, length, density, and orientation desirable for a potential application as photosensitive materials in the manufacture of semiconductor-polymer solar cells

Electro Conductive Alumina Nanocomposites From Different Alumina-Carbides Mixtures

This work presents the results of an electro-discharge machined ceramic composites consisting of a base non-conductive ceramic component such Al2O3, to which is added sufficient amounts of an electro-conductive ceramic nanoparticles such as TiC, TiNC, NbNC, TaNC, and SiC (whiskers) to achieve an electrical resistance of less than about 100W.cm. With these compositions intricate geometries and features as holes, chamfers, slots, angles, changing radii and complex curves can be electro-discharge machined (EDM) into the ceramic body after Pulsed Electrical Current Sintering (PECS) to achieve maximum density and mechanical properties. In EDM, the electrically conductive workpiece or ceramic blank is eroded by electric discharges or sparks which on a small scale generate localized shock waves and intense heat. The four compositions studied were in the same proportion for all raw materials: alumina 42 (vol %) + conductive material (TiC, TiNC, NbNC, and TaNC) 22 (vol %) + SiCw 36 (vol %). Processing was carried out mixing raw materials in the suitable proportions in a polypropylene container with zirconia balls and isopropanol media for 72 hours in order to guarantee the homogeneity of the final compositions. The powders were dried and introduced into a PECS furnace for sintering to 1650°C (100 MPa/2 min). The diameters of the pieces obtained were 20 and about 40 mm and 7 mm thickness. SiC whiskers reinforced electrically conductive ceramic compositions provide a fully dense material with optimal mechanical properties. The capability of electro-discharge machining obtains good surface quality, chip-free edges, dimensional accuracy and complex shapes. The fracture toughness is improved two to three fold over individual ceramic components. Strength and hardness is also increased. Some composites were tested as a cutting tool to machine IN-718 nickel-base superalloy industrial laminating cylinders. The composites were formed and electro-discharge machined to a standard size cutting inser

Varón de 74 años que ingresa por insuficiencia cardíaca: ¿sólo insuficiencia cardíaca?

A 74-year-old male smoker with a history of hypertension, DM type 2, dyslipidemia, permanent AF, and chronic heart failure (HF) who was admitted due to acute cardiac decompensation. The response to treatment with diuretics was very good and the patient was discharged with a request for echocardiography and spirometry in the phase of clinical stability of his HF. Spirometry was diagnostic of a severe COPD, which was undiagnosed, so it was treated with bronchodilators. The case illustrates the problem of the underdiagnosis of COPD in patients with HF even though both diseases coexist very frequently in the same patient.Varón de 74 años, fumador, con antecedentes de hipertensión arterial, diabetes mellitus tipo 2, dislipemia, fibrilación auricular permanente e insuficiencia cardíaca crónica que ingresó por descompensación cardíaca aguda. La respuesta al tratamiento con diuréticos fue muy buena y el paciente fue dado de alta con solicitud de ecocardiografía y espirometría en fase de estabilidad clínica de su insuficiencia cardíaca. La espirometría fue diagnóstica de una enfermedad pulmonar obstructiva crónica (EPOC) grave, por lo que fue tratado con broncodilatadores. El caso ilustra la problemática del infradiagnóstico de la EPOC en pacientes con insuficiencia cardíaca crónica, a pesar de que ambas enfermedades coexisten con mucha frecuencia en el mismo paciente

Cianobacterias presentes en aguas termales, una alternativa para el desarrollo sustentable del campo chihuahuense

Las cianobacterias comprenden un gran y diverso grupo de microorganismos procariotas cuyo origen se remonta hace 3.5 millones de años. Son las principales productoras del oxígeno de nuestro planeta, forman la base de las redes tróficas, tienen una amplia distribución en cualquier tipo de ecosistema terrestre o acuático, entre ellos los ambientes con altas temperaturas y son fuente de una amplia gama de productos de alto valor agregado, los cuales han despertado el interés dentro del campo de la biotecnología actual, de tal manera que se han desarrollado aplicaciones en muchas áreas, siendo la agricultura una de las más importantes. Con base a lo anterior, se estableció como objetivo de este avance de investigación, la exploración de las aguas termales del brote de San Diego de Alcalá, Aldama, Chihuahua, en búsqueda de cianobacterias con potencial uso biotecnológico en el campo chihuahuense. Los resultados evidenciaron la presencia de cianobacterias que pueden ser empleadas en el desarrollo de aplicaciones biotecnológicas, lo cual representa una alternativa viable para el desarrollo del campo chihuahuense

Učinak postupnog blanširanja u otopini kalcijeva klorida na teksturu i strukturu ukiseljenih „jalapeño” paprika

Jalapeño peppers incur texture changes during thermal processing due to loss of turgor pressure, tissue softening, and pectin solubility in the cell wall, which affects their quality and acceptability as a processed product among consumers. The objective of this work is to evaluate the effect of stepwise blanching with calcium chloride solution on firmness, calcium absorption and microstructural changes of jalapeño peppers. Batches of 1 kg of pepper halves were blanched at 65 °C for 4 min at different concentrations of CaCl2 (0, 0.075, 0.15 and 0.3 mol/L). After blanching, the peppers were removed, placed in plastic bags and submerged in a water bath at 65 °C for different holding times (0, 15, 30 and 45 min). Then the peppers were blanched again in an acidified solution at 96 °C for 3 min to remove enzymatic activity. Afterwards, peppers were packed in glass containers with brine at 95 °C and pasteurized at 85 °C for 10 min. The product was stored for 10 days at room temperature, then analyzed for texture, calcium absorption, pH, acidity, and microstructural changes. Results showed that CaCl2 concentration and blanching improved firmness with a maximum value of 3.68 N, a 4.3-fold increase over control. Calcium absorption increased with CaCl2 concentration reaching a maximum of 0.68 g of Ca2+ per kg of samples. Microscopy showed reduced cell wall damage in the samples that were blanched in 0.3 mol/L of CaCl2 at 45 min of holding time. The optimum processing conditions determined in thisstudy can be used for improving the firmness of peppers.Tijekom toplinske obrade mijenja se tekstura „jalapeño” paprika zbog gubitka turgora, mekšanja tkiva i topljivosti pektina u staničnim stijenkama, što utječe na njihovu kakvoću i prihvatljivost među potrošačima. Svrha je ovoga rada bila procijeniti učinak postupnog blanširanja u otopini kalcijeva klorida na čvrstoću tkiva, apsorpciju kalcija i mikrostrukturalne promjene „jalapeño” paprika. Šarže od 1 kg polovica paprika blanširane su 4 minute na 65 °C pri različitim koncentracijama CaCl2 (0; 0,075; 0,15 i 0,3 mol/L). Nakon blanširanja paprike su stavljene u plastične vrećice i potopljene u vodenu kupelj na 65 °C tijekom 0, 15, 30 i 45 min. Zatim su radi inaktivacije enzima 3 minute blanširane u zakiseljenoj otopini pri 96 °C, te pakirane u staklenke s rasolom (pri 95 °C) i pasterizirane na 85 °C tijekom 10 min. Naposljetku su 10 dana skladištene na sobnoj temperaturi, nakon čega je analizirana njihova tekstura, apsorpcija kalcija, pH, kiselost i mikrostrukturalne promjene. Rezultati pokazuju da CaCl2 i blanširanje poboljšavaju čvrstoću tkiva 4,3 puta (na maksimalnih 3,68 N), u usporedbi s kontrolnim uzorkom. Povećanjem koncentracije CaCl2 povećala se apsorpcija kalcija (maksimalno 0,68 g Ca2+/kg paprika). U uzorcima blanširanim 45 min u otopini CaCl2, koncentracije 0,3 mol/L, mikroskopski je utvrđeno manje oštećenje staničnih stijenki. Stoga je zaključeno da se čvrstoća paprika može poboljšati optimiranjem uvjeta prerade

A Double-Blind, Randomized Clinical Trial of Niacinamide 4% versus Hydroquinone 4% in the Treatment of Melasma

Background. Multiple modalities have been used in the treatment of melasma with variable success. Niacinamide has anti-inflammatory properties and is able to decrease the transfer of melanosomes. Objective. To evaluate the therapeutic effect of topical niacinamide versus hydroquinone (HQ) in melasma patients. Patients and Methods. Twenty-seven melasma patients were randomized to receive for eight weeks 4% niacinamide cream on one side of the face, and 4% HQ cream on the other. Sunscreen was applied along the observation period. They were assessed by noninvasive techniques for the evaluation of skin color, as well as subjective scales and histological sections initially and after the treatment with niacinamide. Results. All patients showed pigment improvement with both treatments. Colorimetric measures did not show statistical differences between both sides. However, good to excellent improvement was observed with niacinamide in 44% of patients, compared to 55% with HQ. Niacinamide reduced importantly the mast cell infiltrate and showed improvement of solar elastosis in melasma skin. Side effects were present in 18% with niacinamide versus 29% with HQ. Conclusion. Niacinamide induces a decrease in pigmentation, inflammatory infiltrate, and solar elastosis. Niacinamide is a safe and effective therapeutic agent for this condition

DESARROLLO DE UN INSTRUMENTO PARA LA EVALUACIÓN DE LOS PROGRAMAS DE EDUCACIÓN SUPERIOR EN CIENCIAS DE LA SALUD

Se elaboró un instrumento para la evaluación de programas de educación superior en ciencias de la salud en México. El objetivo es contribuir a la mejoría continua de los procesos de evaluación y acreditación a los que actualmente están sometidos dichos programas. Se hacen explícitos los pasos para la elaboración del instrumento, así como sus contenidos, modelos y escalas; de igual manera, los procedimientos para la obtención de la información requerida por el propio instrumento. Por último, se hacen breves consideraciones sobre cuestiones éticas de la evaluación y la forma en que se abordan en el instrumento desarrollado.Palabras clave: Evaluación de programas, Métodos de evaluación, Criterios de evaluación, Educación de profesionales de la salud, Educación médica.Program evaluation, Evaluation methods, Evaluation criteria, Allied health occupations education, Medical education

Anthropometric Profile Assessed by Bioimpedance and Anthropometry Measures of Male and Female Rugby Players Competing in the Spanish National League

Different rugby positions make different demands on players. It therefore follows that optimum body composition may vary according to the position played. Using anthropometry and bioimpedance analysis (BIA) to assess body composition, the present study aimed to compare the effect of sex and position on body composition variables using anthropometry and BIA methods. A total of 100 competitive rugby players (35 women and 65 men) competing in the First Spanish National League were recruited voluntarily and for convenience for this study. In the laboratory, body composition was assessed by anthropometry, following the recommendations established by the International Society for the Advancement of Kinanthropometry (ISAK), and by direct segmental multi-frequency BIA, following the guidelines established by the Spanish Group of Kinanthropometry (GREC) of the Spanish Federation of Sports Medicine (FEMEDE). We found sex-related differences in height, weight, body mass index and body fat (%) by anthropometry and in body lean mass (%) by DSM-BIA, in 4 of the 6 skinfolds assessed (p < 0.05). We also observed position-related differences in all the variables assessed (p < 0.05) except for lean body mass, as measured by both methods of determining body composition, and front thigh skinfold. Body composition and ∑6skinfolds differs according to sex and playing position, backs (16.6 ± 3.8% and 92.3 ± 33.9 mm,) vs. forwards (20.0 ± 6.7 and 115.3 ± 37.6 mm), and the muscle-adipose (meso-endomorphic somatotype) development predominated in both sexes. Thus, forwards of both sexes are taller, heavier and fatter, possibly due to the specific demands of this position. In addition, body composition measurements vary according to the method used (DSM-BIA vs. anthropometry), indicating that anthropometry is probably the best body composition assessment method

HF broadband antenna design for shipboard communications: Simulation and measurements

The objective pursued in this work is to highlight the convenience of using electromagnetic simulation software as an alternative to the traditional scale model measurement when dealing with the design of HF antennas on real complex platforms. The experience was developed during the building process of a real vessel. A low and a medium band antennas (fan-wire type) were designed ad-hoc for this project. The HF broadband antennas’ study covered from the preliminary design stages to the final verification measurements completed onboard the ship. The experiment has demonstrated that more accurate results can be obtained when using an adequate electromagnetic simulation code, which, besides, brings important advantages in flexibility and usability. These advantages, inherent to the use of virtual models, hinge on the ability of the simulation tools to properly handle any modification of the vessel’s structure that might arise during the platform construction