Comportamiento catalítico de una Bentonita modificada con Manganeso en la oxidación en fase húmeda de naranja de metilo con peróxido de hidrógeno

En este trabajo se presenta un estudio comparativo en el que se introduce manganeso en una bentonita colombiana proveniente del Valle del Cauca (BVC) utilizando tres métodos: i) pilarización con Al 2 O 3 y posterior impregnación húmeda con una disolución acuosa de manganeso, ii) co-intercalación con una disolución oligomérica mixta de Al-Mn seguida de una etapa de calcinación y iii) homoionización con Mn 2+ y posterior formación in-situ de agregados tipo MnS. Los sólidos resultantes son caracterizados por espectroscopía de absorción atómica (EAA), capacidad de intercambio catiónico (CIC) y difracción de rayos X en polvo (DRX), y evaluados como catalizadores en la oxidación de naranja de metilo con peróxido de hidrógeno

Computerized Machine for Cutting Space Shuttle Thermal Tiles

A report presents the concept of a machine aboard the space shuttle that would cut oversized thermal-tile blanks to precise sizes and shapes needed to replace tiles that were damaged or lost during ascent to orbit. The machine would include a computer-controlled jigsaw enclosed in a clear acrylic shell that would prevent escape of cutting debris. A vacuum motor would collect the debris into a reservoir and would hold a tile blank securely in place. A database stored in the computer would contain the unique shape and dimensions of every tile. Once a broken or missing tile was identified, its identification number would be entered into the computer, wherein the cutting pattern associated with that number would be retrieved from the database. A tile blank would be locked into a crib in the machine, the shell would be closed (proximity sensors would prevent activation of the machine while the shell was open), and a "cut" command would be sent from the computer. A blade would be moved around the crib like a plotter, cutting the tile to the required size and shape. Once the tile was cut, an astronaut would take a space walk for installation

Demographic Statistics 1990

Correspondenci

Mitochondrial decay in the aging rat heart : changes in fatty acid-supported bioenergetics and macromolecular organization of the electron transport system

Decline in cardiac pump function is a hallmark of aging where mitochondrial decay is an important underlying cause. Although certainly multifactorial in nature, both dysfunction of the machinery involved in the chemiosmotic process of energy transduction and lower capacity to maintain fatty acid-driven respiration are identified as intrinsic factors of mitochondrial decay in the aged myocardium. Age-associated destabilization of electron transport supercomplexes as a potential factor of mitochondrial decay in the rat heart. Defective operation of the electron transport chain (ETC) constitutes a key mechanism involved in the age-associated loss of mitochondrial energy metabolism. Nevertheless, the molecular events underlying inefficient electron flux that ultimately leads to higher superoxide appearance and impaired respiration are not fully known. As recent biophysical evidence shows that the ETC may form large macromolecular assemblies (i.e. supercomplexes) that disintegrate in certain pathologies (e.g. heart failure or Barth syndrome) reminiscent of aging, we investigated the hypothesis that alterations in supercomplexes are partly responsible for the age-related loss of cardiac ETC function. In this dissertation, age-associated changes in supercomplex organization and stability were investigated in subsarcolemmal (SSM) and interfibrillary (IFM) mitochondria isolated from cardiac tissue from young (3-5 months) and old (24-28 months) male Fischer 344 rats. Blue native-PAGE (BN-PAGE) analysis of digitonin-solubilized mitochondrial membranes coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to investigate supercomplex organization. Results show that both SSM and IFM display supercomplexes comprised of various stoichiometries of complexes I, III and IV (never complex II), which typically organize as high mass (1500-2300 kDa) assemblies containing up to four copies of complex IV (i.e. I₁III₂IV[subscript N]-type supercomplexes). Interestingly, analysis of IFM proteins showed that, in general, supercomplex levels declined by up to 15 % (p < 0.05) with age; however, different degrees of supercomplex deterioration were observed, depending on the particular supercomplex investigated. Supercomplexes of the highest molecular weights (i.e. 1900-2300 kDa), which were also composed of the most complex stoichiometries (i.e. I1III2IVN, N ≥ 2), were primarily lost with age. In particular, I₁III₂IV₂, I₁III₂IV₃ and I₁III₂IV₄ supercomplexes were found to decline by 13% (p < 0.05), 30% (p < 0.05) and 45% (p < 0.05), respectively, on an age basis. Therefore, the age-associated loss of supercomplexes in IFM stems from destabilization of the assemblies that comprise several copies of complex IV, which could partially limit proper electron transfer to O₂ for its reduction, affecting mitochondrial respiratory capacity. In contrast to IFM, the aging defects of SSM supercomplexes appeared to be confined to the assembly comprised of only one copy of complex IV (I₁III₂IV₁, 1700 kDa) (37% loss; p = 0.06), while the higher molecular weight supercomplex sub-types that were most affected in IFM (i.e. I₁III₂IV[subscript N], N ≥ 2) were not significantly altered with age. Thus, the results from this dissertation indicate that mitochondria from different subcellular locations in the myocyte show different degrees of supercomplex destabilization in the aging rat heart. The more robust supercomplex deficits noted for IFM fit well with previous observations that electron transport characteristics of this subpopulation are more adversely affected with age than SSM. Although the underlying factor(s) of supercomplex deterioration are not fully known, the hypothesis that age-related alterations of certain constituents of the IMM (e.g. cardiolipin) may be important factors of supercomplex destabilization in cardiac mitochondria was investigated in this dissertation. To this end, LC-MS/MS characterization of supercomplex proteins and HPLC analysis of cardiolipin were used as approaches to elucidate potential factor(s) of supercomplex destabilization in the aging rat heart. Age-related alterations of cardiolipin levels and its acyl-chain content showed a strong parallel to the age-associated destabilization of supercomplexes. Specifically, cardiolipin levels declined by 10% (p < 0.05) in IFM, the mitochondrial subpopulation displaying the highest degree of supercomplex deterioration. In addition, the content of (18:2)₄-cardiolipin, the predominant species in the heart, was found to decline by 50% (p < 0.05) on average in both populations of cardiac mitochondria. Therefore, the data presented in this dissertation indicate that changes in cardiolipin may be at least one of the factors involved in supercomplex destabilization in the aging heart. Age-related decline in carnitine palmitoyltransferase I (CPT1) activity as a mitochondrial lesion that limits fatty acid catabolism in the rat heart. Loss of fatty acid utilization, another intrinsic factor of mitochondrial decay in the aged myocardium, has been associated with age-related alterations in the activity of carnitine palmitoyltransferase 1 (CPT1), the rate-controlling enzyme for overall fatty acid β-oxidation. Nevertheless, the exact molecular mechanism involved in the age-related loss of fatty acid-driven bioenergetics is not fully understood. In this dissertation, it was also investigated whether the aging lesion for fatty oxidation lies in a particular mitochondrial subpopulation or more generally results from cardiac decrements in L-carnitine levels. In order to clarify the role of each one of these factors, the effect of long-term dietary supplementation with the L-carnitine analogue, acetyl-L-carnitine (ALCAR), was also investigated. Results show that aging selectively decreases CPT1 activity in IFM by reducing enzyme catalytic efficiency for palmitoyl-CoA. IFM displayed a 28% (p < 0.05) loss of CPT1 activity, which correlated with a decline (41%, p < 0.05) in palmitoyl-CoA-driven state 3 respiration. Interestingly, SSM had preserved enzyme function and efficiently utilized palmitate. Analysis of IFM CPT1 kinetics showed both diminished V[subscript max] and K[subscript m] (60% and 49% respectively, p < 0.05) when palmitoyl-CoA was the substrate. However, no age-related changes in enzyme kinetics were evident with respect to L-carnitine. ALCAR supplementation restored CPT1 activity in heart IFM, but not apparently through remediation of L-carnitine levels. Rather, ALCAR influenced enzyme activity over time, potentially by modulating conditions in the aging heart that ultimately affect palmitoyl-CoA binding and CPT1 kinetics. In conclusion, this dissertation presents a characterization of age-associated alterations in the macromolecular organization of the IMM components that could partly explain the loss of mitochondrial oxidative capacity that affects the aging heart. In addition, the characterization of an age-related lesion of the controlling enzyme for β-oxidation is presented as another important factor that limits mitochondrial function and energy metabolism in cardiac mitochondria

Task 10: Research an Alternative Instructional Design Model

Under authority of the Federal Aviation Administration (FAA), the Center of Excellence (COE) Technical Training Human Performance (TTHP) Task 10 research team has prepared a comprehensive technical report and an executive summary for the Air Traffic Organization (ATO) concerning the instructional development (ID) of occupational education and training for Air Traffic (AT) controllers and Technical Operations (TO) technicians. Research included: • Front-end analysis of available FAA courses and government furnished information (GFI), including course-development documentation and associated guidance, policies, and regulations. • Structured and semi-structured data-gathering techniques in cooperation with Instructional Systems Specialists (ISS), ISS Managers, and Requirements personnel. • Informal observations of validation events for Air Traffic training. • Analysis of the relevant literature from academic, government, and industry domains. The executive summary describes the findings and observations of issues directly related to the ID process and potential solutions based on findings from this comparative analysis. The comprehensive report that follows includes these and additional observations and recommendations as well as the project overview, an introduction to best practice research, the research methodology, presentation and analysis of the results, and discussion of the findings and conclusions

Efecto de la aplicación del protocolo modificado por Henao y Pérez (2011), para el manejo de la intimidación escolar y la conducta prosocial en adolescentes del grado sexto de educación media de la institución educativa bello horizonte del municipio de Florencia-Caquetá

TablasEl proyecto de investigación, Efecto de aplicación del Protocolo modificado por Henao y Pérez (2011), para el manejo de la intimidación escolar y la conducta pro social, en adolescentes de los grados sexto A y sexto B de educación media de la Institución Educativa Bello Horizonte del Municipio de Florencia-Caquetá, constituyó un trabajo en el que se aplicó el Protocolo de Intervención modificado por Henao y Pérez (2011), en la intimidación escolar y la conducta pro social, y donde se logró detectar a través de once sesiones de este modelo, que el nivel de acoso escolar es alto, que los estudiantes se pierden el respeto entre sí, al igual que la práctica de antivalores, dándole cabida a la violencia, y al deterioro psíquico, emocional y físico de la o las personas víctimas del bullying. De igual manera, aplicado este procedimiento se trató de minimizar la problemática, creando conciencia en los estudiantes de lo perjudicial que es para la integridad humana el ser autor del bullying, lo importante que es orientar a los educandos desde un crecimiento personal, hacia la práctica de valores y de la actitud pro social para el compartimiento de una convivencia pacífica en el aula.The research project, Effect of application of Protocol amended by Henao and Perez (2011), for the management of school the intimidation and prosocial behavior in adolescents in grades six A and six B secondary education of School Bello Horizonte Florence Township Caquetá, was a work in which we applied the modified Intervention Protocol Henao and Perez (2011), school bullying and pro-social behavior, and where achievement detect through eleven sessions of this model, the level of bullying is high, students will lose respect for each other, as well as the practice of anti-values, give space to violence, and deteriorating mental, emotional and physical persons or victims of bullyng . Similarly, treatment applied this procedure to minimize the problem, creating awareness in students of how detrimental to human integrity is being Bullyng author, how important it is to guide learners from personal growth, to practice values and pro-social attitudes to the compartment of peaceful coexistence in the classroom

Deletion of Endothelial Estrogen Receptor Alpha Reduces Arterial Stiffness in Angiotensin II infused-Female Mice

Vascular stiffness is a naturally occurring phenomenon associated with aging, but conditions such as obesity and type 2 diabetes accelerate its development, particularly in women. The presence of vascular stiffness increases significantly the risk of cardiovascular disease (CVD). Under physiological conditions, estrogen signaling via estrogen receptor alpha (ERα) increases bioavailable nitric oxide in the endothelium and decreases stiffness. Nevertheless, large clinical trials have failed to demonstrate beneficial cardiovascular effects of estrogen therapy. Our previous work has shown that under conditions of over-nutrition, the lack of ERα ameliorates arterial stiffening in obese and insulin resistant females. Given the central role that activation of the Renin-Angiotensin-System (RAS) has in the pathogenesis of CVD, in the present study we examine the effect of an Angiotensin II (Ang II) infusion in female mice lacking endothelial cell (EC)