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on la finalidad de obtener callos embriogénicos y luego embriones somáticos de los mismos en el cultivo del café (Coffea canephora P.), se cultivaron in vitro explantes foliares de ramas ortotrópicas de plantas establecidas en campo. Los medios de cultivo contenían las sales minerales recomendadas por Murashige y Skoog (1962) y como reguladores del crecimiento se estudiaron el 2,4-D (0.5 mg/L) y la Kinetina (2.0 mg/L), así como el RIZOBAC (0.4-1.8 mg/L) para la inducción del callo embriogénico. Se observó que la dosis de 0.9 mg/L de RIZOBAC y 2.0 mg/L de Kinetina favorecieron notablemente la formación de callos embriogénicos de alta frecuencia (46.0-98.7 %). Estos callos cultivados en un medio suplementado con ANA (0.1 mg/L) y Kinetina (0.5 mg/L) originaron embriones somáticos en diferentes estadios de desarrollo. Palabras clave: Robusta; clones; callos; 2,4-D; Kinetina; RIZOBAC.

El presente estudio se realizó en el Instituto Nacional de Ciencias Agrícolas de Cuba, con el objetivo de evaluar el efecto de diferentes concentraciones del compuesto bacteriano CB-1 sobre el crecimiento y desarrollo in vitro de tres clones seleccionados de cafeto, var. Robusta, así como valorar la posible sustitución de la auxina AIA en el medio de cultivo establecido para la multiplicación del cafeto, donde se realizaron ensayos durante la fase de aclimatización de las vitroplantas. Se estudiaron diferentes tratamientos. Como testigo se empleó el medio de multiplicación establecido convencionalmente, mientras que los otros tres tratamientos consistieron en sustituir el AIÁ del medio por el CB-1 a diferentes concentraciones (0.5; 1.0 y 2.0 mg.L-1). Durante la aclimatización, se estudió el efecto del biopreparado (sólido y líquido), a través de la exposición del sistema radical de las plántulas a una concentración de 20 mg/L del compuesto por 30 minutos. Se evaluaron las variables: número de explantes vivos, altura de la vitroplanta (cm), número de brotes, número de pares de hojas, porcentaje de plantas enraizadas y contenido de proteínas totales y fenoles (mg/g tejido). Como resultado se detectaron variaciones en la respuesta de los clones estudiados, así como en los indicadores evaluados, obteniéndose mayor capacidad de respuesta en el clon M-229 y con concentraciones de 0.5 y 1.0 mg.L-1 de CB-1. Se obtuvo mayor efectividad con el CB-1 en estado líquido durante la aclimatización de las vitroplantas. Se demostró la factibilidad del empleo del nuevo biopreparado en la estimulación del crecimiento vegetal.

Abstract Background High dosage of intravenous immunoglobulin (IVIG) has been observed as a possible activator of HIV gene expression in latently infected resting CD4+ T-cells, leading to a substantial decrease in both the reservoir and the residual plasma viremia when added to effective ART. IVIG treatment has also been reported to expand T regulatory cells (Tregs). The aim of this study was to evaluate possible long-term effect of IVIG treatment on residual viremia and T-lymphocyte activation. Methods Nine HIV-infected subjects on effective ART included in a previously reported study on IVIG treatment were evaluated 48-104 weeks after therapy. In addition, 14 HIV-infected controls on suppressive ART were included. HIV-1 RNA was analyzed in cell-free plasma by using an ultrasensitive PCR-method with a detection limit of 2 copies/mL. T-lymphocyte activation markers and serum interleukins were measured. Results Plasma residual viremia rebounded to pre-treatment levels, 48-104 weeks after the initial decrease that was observed following treatment with high-dosage IVIG. No long-term effect was observed regarding T-lymphocyte activation markers, T-regulatory cells or serum interleukins. In a post-hoc analysis, a correlation between plasma HIV-1-RNA and CD4+ T-cell count was found in both IVIG-treated patients and controls. Conclusions These results indicate that the decrease in the latent HIV-1 pool observed during IVIG treatment is transient. Although not our primary objective, we found a correlation between HIV-1 RNA and CD4+ T-cell count suggesting the possibility that patients with a higher CD4+ T-cell count might harbor a larger residual pool of latently infected CD4+ T-cells.

Abstract Background The latency of HIV-1 in resting CD4+ T-lymphocytes constitutes a major obstacle for the eradication of virus in patients on antiretroviral therapy (ART). As yet, no approach to reduce this viral reservoir has proven effective. Methods Nine subjects on effective ART were included in the study and treated with high dosage intravenous immunoglobulin (IVIG) for five consecutive days. Seven of those had detectable levels of replication-competent virus in the latent reservoir and were thus possible to evaluate. Highly purified resting memory CD4+ T-cells were activated and cells containing replication-competent HIV-1 were quantified. HIV-1 from plasma and activated memory CD4+ T-cells were compared with single genome sequencing (SGS) of the gag region. T-lymphocyte activation markers and serum interleukins were measured. Results The latent HIV-1 pool decreased with in median 68% after IVIG was added to effective ART. The reservoir decreased in five, whereas no decrease was found in two subjects with detectable virus. Plasma HIV-1 RNA ≥ 2 copies/mL was detected in five of seven subjects at baseline, but in only one at follow-up after 8–12 weeks. The decrease of the latent HIV-1 pool and the residual plasma viremia was preceded by a transitory low-level increase in plasma HIV-1 RNA and serum interleukin 7 (IL-7) levels, and followed by an expansion of T regulatory cells. The magnitude of the viral increase in plasma correlated to the size of the latent HIV-1 pool and SGS of the gag region showed that viral clones from plasma clustered together with virus from activated memory T-cells, pointing to the latent reservoir as the source of HIV-1 RNA in plasma. Conclusion The findings from this uncontrolled proof-of-concept study suggest that the reservoir became accessible by IVIG treatment through activation of HIV-1 gene expression in latently-infected resting CD4+ T-cells. We propose that IVIG should be further evaluated as an adjuvant to effective ART.

El objetivo de este trabajo es conocer los factores que influyen de manera significativa sobre el rendimiento de los alumnos en Matemáticas Empresariales. Con este fin, y basándonos en la literatura existente sobre el tema se propone un modelo donde se tienen en cuenta algunas de las variables que habitualmente se consideran más relevantes junto con factores específicos que afectan al problema que queremos analizar. Uno de los trabajos pioneros en este campo de obligada referencia en todos los estudios es el Informe Coleman, publicado en 1966 bajo el título "Equality of Educational Opportunity", donde se analizan los factores determinantes del rendimiento de más de medio millón de alumnos en USA. Los resultados del citado informe han sido objetos de múltiples controversias tanto por cuestiones técnicas como por las conclusiones que de él se extraen que básicamente son que los resultados escolares dependen sobre todo de la extracción social del alumno y por tanto la actividad educativa desarrollada en la escuela y la inversión en recursos o en la mejora de la capacitación del profesorado apenas tiene efectos sobre el rendimiento. Este trabajo es considerado como el punto de partida de muchos otros en los que se analiza la enseñanza como un proceso productivo donde el output educativo se obtiene a partir de una serie de inputs de diversa índole aportados por los estudiantes, las familias y el centro escolar

Echinochloa pyramidalis (Lam.) Hitchc. & Chase is an African grass with C4 photosynthesis, high biomass production, and high vegetative propagation that is tolerant to grazing and able to grow in flooded and dry conditions. Thus, it is highly invasive in tropical freshwater marshes where it is intentionally planted by ranchers to increase cattle production. This invasion is reducing plant biodiversity by increasing the invader's aerial coverage, changing wetland hydrology and causing soil physicochemical changes such as vertical accretion. Reducing the dominance of this species and increasing the density of native wetland species is a difficult, expensive, and time-consuming process. We applied a series of disturbance treatments aimed at eliminating E. pyramidalis and recovering the native vegetation of a partially invaded freshwater marsh. Treatments included physical (cutting, soil disking, transplanting individuals of the key native species Sagittaria lancifolia subsp. media (Micheli) Bogin, and/or reducing light with shade mesh) and/or chemical (spraying Round-Up™ herbicide) disturbances. At the end of the experiment, four of the five treatments used were effective in increasing the cover and biomass of native species and reducing that of E. pyramidalis. The combination of these treatments should be used to generate a proposal for the restoration of tropical wetlands invaded by non-native grasses. A promising treatment is using soil disked to soften the soil and destroy belowground structures such as roots and rhizomes. This treatment would be more promising if combined with the use of shade cloth. If it is desirable not to impact the soil or if there is not enough budget to make an effort to include active restoration disking soil, the use of shade cloth will suffice, although the recovery of native vegetation will be slower.

The persistence of propanil in soil and aquatic environments along with the possible accumulation of toxic degradation products, such as chloroanilines, is of environmental concern. In this work, a continuous small-scale bioprocess to degrade the herbicide propanil, its main catabolic by-product, 3,4-dichloroaniline (3,4-DCA), and the herbicide adjuvants is carried out. A microbial consortium, constituted by nine bacterial genera, was selected. The isolated strains, identified by amplification and sequencing of their 16S rDNA, were: Acidovorax sp., Luteibacter (rhizovicinus), Xanthomonas sp., Flavobacterium sp., Variovorax sp., Acinetobacter (calcoaceticus), Pseudomonas sp., Rhodococcus sp., and Kocuria sp. The ability of the microbial consortium to degrade the herbicide was evaluated in a biofilm reactor at propanil loading rates ranging from 1.9 to 36.8 mg L(-1) h(-1). Complete removal of propanil, 3,4-DCA, chemical oxygen demand and total organic carbon was obtained at propanil loading rates up to 24.9 mg L(-1) h(-1). At higher loading rates, the removal efficiencies decayed. Four of the identified strains could grow individually in propanil, and 3,4-DCA: Pseudomonas sp., Acinetobacter calcoaceticus, Rhodococcus sp., and Xanthomonas sp. The Kokuria strain grew on 3,4-DCA, but not on propanil. The first three bacteria have been related to biodegradation of phenyl urea herbicides or chlorinated anilines. Although some strains of the genera Xanthomonas and Kocuria have a role in the biodegradation of several xenobiotic compounds, as far as we know, there are no reports about degradation of propanil by Xanthomonas or 3,4-DCA by Kocuria species.

Objective: To verify that the diaphragmatic pacemaker is a form of respiratory support that can be used to replace a volumetric respirator in cervical spinal injury patients with cervical spinal lesion and diaphragmatic paralysis by means of its comparison with the traditional volumetric respirator., Design: Retrospective study of a prospective database and age-matched case-control study., Setting: Intensive Care Unit and Intermediate Care Respiratory Unit, Paraplegics National Hospital, Toledo (Spain)., Patients: We collected data on all patients discharged from the Hospital with permanent respiratory support by volumetric respirator or diaphragmatic pacemaker during a follow-up period of 25 years. Personal interviews were conducted to evaluate health-related quality of life. Comparison and survival tests were used for statistical comparisons., Interventions: Quality of life questionnaire., Main Variables: The main variables collected were demographic data, hospital stay, mortality, family reintegration and health-related quality of life., Results: We evaluated the clinical records of 101 patients, 37 in the pacemaker-group and 64 in the volumetric respirator-group. Our results show that ICU admission duration and hospitalization as well as family reintegration, without significant differences, with a tendency to greater survival in pacemaker patients (18.18 versus 9.67 years by the Kaplan-Meier method, p<0.001). However, this difference becomes non-significant (p=0.06) after adjustment of the groups by age. Furthermore, better quality of life was found in these same patients with pacemakers in terms of security, communication, sociability, comfort and mobility in the patients., Conclusions: Diaphragmatic pacemaker ventilation is an effective alternative to mechanical ventilation with similar efficacy that improve quality of life in patients with severe respiratory failure due to cervical spinal cord injury., (Copyright © 2009 Elsevier España, S.L. y SEMICYUC. All rights reserved.)

Given the importance attributed to the protection of health care workers against viral Hepatitis B (VHB) by the World Health Organization (WHO) and the Center for Disease Control (CDC), in 1993, the Instituto Peruano del Seguro Social (Social Security Peruvian Institute), today known as ESSALUD, ruled the vaccination of personnel in risk working in the 4 national hospitals, using Cuban vaccine Heberbiovac HB (20mg, schedule 0, 1, 2 months). Our purpose was to evaluate the antibody persistence in the vaccinated individuals after six years from immunization, and the possible presence of HB virus infection markers. Sera from 144 health care workers were studied, for a 70.24% coverage, in relation to the initially seroprotected in the 1993 study. For markers detection, commercial immunoenzymatic methods were used. HBsAg and anti-HBc were negative in all the serology samples studied, thus we conclude that no evidence of infection by this virus was found in any of the vaccinated subjects. AntiHBs was positive, being all of them seroconverted, with seroprotection and hyperresponse as of 91.6% and 43.7% respectively. The mean life time of antiHBs (t 1/2) is three years,predicting that the antibodies level will be over 10 IU/l until after 15 years from the end of the schedule. The subjects under 40 had significantly higher levels of seroprotection and hyperresponse, being the females those that stayed in the upper categories of response. Evaluation of the post-reinforcement memory in the seroconverted, not protected cases, is recommended, as well as extend the work with ESSALUD to other hospitals in the country.