970 resultados para compositi geopolimeri lana termoisolanti
Resumo:
Desde el inicio de la ganadería ovina en la Patagonia hasta hoy se han generado procesos de deterioro de los pastizales naturales en forma generalizada. Dichos procesos en gran medida están asociados al uso inadecuado por el ganado ovino. A lo largo de los últimos 50 años se han realizado innumerables trabajos de investigación con el fin de describir y comprender los procesos mencionados anteriormente, así como desarrollar tecnologías que permitan frenar o revertir el deterioro generado por el uso ganadero. A pesar del esfuerzo realizado, trabajos recientes demuestran la muy escasa aplicación de estas tecnologías e inserción de los técnicos en el manejo de pastizales de los establecimientos ganaderos. Una de las principales tecnologías promovidas y muy escasamente utilizada es el ajuste de carga. El presente trabajo indaga sobre las razones que guían al productor en las decisiones y busca generar información que permita planificar nuevas estrategias para abordar la problemática planteada. Para esto se realizaron entrevistas semi-estructuradas a productores ganaderos del departamento Tehuelches de la provincia de Chubut y a responsables de asociaciones de productores e instituciones técnicas. Asimismo se analizaron datos productivos de 2 establecimientos ganaderos de la zona, se analizaron datos regionales de productividad del pastizal y se realizaron análisis económicos de diferentes situaciones productivas. Los resultados del trabajo muestran que el productor posee un complejo entramado de razones que explican sus decisiones y se pone en evidencia la complejidad de manejar sistemas pastoriles que poseen una variabilidad natural muy importante. Pareciera que existe una fuerte racionalidad económica con especial énfasis en los ingresos por lana que determina su comportamiento con respecto al ajuste de carga. De acuerdo a los datos productivos analizados, en los años con mayor carga de animales por hectárea mayor fue la producción de lana, funcionando esto como una señal muy fuerte para el productor. La realización de análisis económicos que incluyan no solo los ingresos sino también otras variables económicas del sistema resultan muy importantes para comprender el problema. Se plantea como importante el análisis de los costos ambientales del deterioro de los pastizales desde las diferentes perspectivas existentes. Finalmente se plantea como necesario la realización de un plan estratégico de manejo de los pastizales patagónicos.
Resumo:
La Argentina, Bolivia y Perú, son los países con mayor cantidad de camélidos sudamericanos, en Argentina hay guanacos, llamas y vicuñas. En la Patagonia se destaca la existencia de guanacos mientras que en la región del NOA (Catamarca, Jujuy, La Rioja, Salta, Santiago del Estero y Tucumán) se encuentran vicuñas y llamas. De estas tres especies, la llama es la que puede ser considerada doméstica. La característica endémica de este tipo de ganado en la región sur del continente americano y las condiciones de manejo en la Argentina, entre otras cuestiones, me impulsaron a elaborar la propuesta de un proyecto de desarrollo rural para Santa María de Catamarca, que tenga por población objetivo a los productores de llamas. El proyecto no fue llevado a la práctica. Dado que la elaboración del proyecto está en una etapa inicial y la idea es diseñarlo de forma participativa, el objetivo del trabajo es identificar cuales debieran ser los pasos a seguir en el diseño del proyecto para que el mismo se oriente a un proceso de desarrollo. Los avances se observan principalmente en el análisis de información de fuentes secundarias y entrevistas, de manera tal que permitió elaborar un marco de la situación y contexto. Además, se cuenta con la información obtenida de una dinámica de diagnóstico a través del árbol de problemas y soluciones efectuado con habitantes de la región donde se llevaría adelante el proyecto. Por lo tanto, este trabajo presenta al lector una propuesta preliminar de proyecto de desarrollo rural vinculado a los productores de llamas de Santa María de Catamarca y a su vez una propuesta metodológica sobre como se deberían llevar adelante las etapas que restan a fin de concretar un proyecto de desarrollo rural planificado de forma participativa.
Resumo:
Los sistemas agropecuarios extrapampeanos de Argentina presentan características socioeconómicas diferentes a los evidenciados en la zona núcleo de producción agrícola. Estas áreas comúnmente llamadas desfavorecidas por sus características agroecológicas sostienen producciones de tipo familiares orientadas fundamentalmente a sistemas extensivos de producción ganadera. El área de estudio se enmarca dentro de estas áreas desfavorecidas, ubicadas en el noroeste de la provincia de Córdoba. La información disponible por su fragmentación geográfica o bien por la invisibilidad de sus productores es escasa o imprecisa lo que induce problemas conexos en el diseño de políticas de desarrollo rural adecuadas a estos sistemas productivos. En ese sentido se inicia el estudio de sus componentes sociológicos y productivos. Esto permite reconocer la heterogeneidad presente e identificar los actores sociales intervinientes. La estructura agraria supone bajo un proceso histórico de territorialización una distribución de los medios de producción: tierra y trabajo. El factor tierra presenta una distribución asimétrica con tendencia a la concentración como sucede en el resto de la provincia y en relación al trabajo la mayoría de las explotaciones agropecuarias presentan trabajo de tipo familiar. Ambos componentes propiedad parcelaria y trabajo familiar típicos de las economías campesinas. La producción ovina es tradicional en la zona de estudio y su orientación es mixta para la producción de lana y cordero liviano que es vendido en su amplia mayoría de forma informal al mercado próximo. La lana que se produce en la zona es de tipo mediana a gruesa con excelente aptitud para la confección de alfombras Estos productores son considerados por el estado en tanto conforman los centros de acopio de lana en la medida que son sujetos beneficiarios de programas nacionales pero siempre intermediados por ONG que implican la acción de nuevos actores sociales al área de estudio.
Resumo:
Why a chapter on Perspectives and Integration in SOLAS Science in this book? SOLAS science by its nature deals with interactions that occur: across a wide spectrum of time and space scales, involve gases and particles, between the ocean and the atmosphere, across many disciplines including chemistry, biology, optics, physics, mathematics, computing, socio-economics and consequently interactions between many different scientists and across scientific generations. This chapter provides a guide through the remarkable diversity of cross-cutting approaches and tools in the gigantic puzzle of the SOLAS realm. Here we overview the existing prime components of atmospheric and oceanic observing systems, with the acquisition of ocean–atmosphere observables either from in situ or from satellites, the rich hierarchy of models to test our knowledge of Earth System functioning, and the tremendous efforts accomplished over the last decade within the COST Action 735 and SOLAS Integration project frameworks to understand, as best we can, the current physical and biogeochemical state of the atmosphere and ocean commons. A few SOLAS integrative studies illustrate the full meaning of interactions, paving the way for even tighter connections between thematic fields. Ultimately, SOLAS research will also develop with an enhanced consideration of societal demand while preserving fundamental research coherency.
Resumo:
The potentially significant role of the biogenic trace gas dimethylsulfide (DMS) in determining the Earth's radiation budget makes it necessary to accurately reproduce seawater DMS distribution and quantify its global flux across the sea/air interface. Following a threefold increase of data (from 15,000 to over 47,000) in the global surface ocean DMS database over the last decade, new global monthly climatologies of surface ocean DMS concentration and sea-to-air emission flux are presented as updates of those constructed 10 years ago. Interpolation/extrapolation techniques were applied to project the discrete concentration data onto a first guess field based on Longhurst's biogeographic provinces. Further objective analysis allowed us to obtain the final monthly maps. The new climatology projects DMS concentrations typically in the range of 1–7 nM, with higher levels occurring in the high latitudes, and with a general trend toward increasing concentration in summer. The increased size and distribution of the observations in the DMS database have produced in the new climatology substantially lower DMS concentrations in the polar latitudes and generally higher DMS concentrations in regions that were severely undersampled 10 years ago, such as the southern Indian Ocean. Using the new DMS concentration climatology in conjunction with state-of-the-art parameterizations for the sea/air gas transfer velocity and climatological wind fields, we estimate that 28.1 (17.6–34.4) Tg of sulfur are transferred from the oceans into the atmosphere annually in the form of DMS. This represents a global emission increase of 17% with respect to the equivalent calculation using the previous climatology. This new DMS climatology represents a valuable tool for atmospheric chemistry, climate, and Earth System models.
Resumo:
FK506 binding protein-like (FKBPL) and its peptide derivatives exert potent anti-angiogenic activity and and control tumour growth in xenograft models, when administered exogenously. However, the role of endogenous FKBPL in angiogenesis is not well characterised. Here we investigated the molecular effects of the endogenous protein and its peptide derivative, AD-01, leading to their anti-migratory activity. Inhibition of secreted FKBPL using a blocking antibody or siRNA-mediated knockdown of FKBPL accelerated the migration of human microvascular endothelial cells (HMEC-1). Furthermore, MDA-MB-231 tumour cells stably overexpressing FKBPL inhibited tumour vascular development suggesting that FKBPL secreted from tumour cells could inhibit angiogenesis. Whilst FKBPL and AD-01 target CD44, the nature of this interaction is not known and here we have further interrogated this aspect. We have demonstrated that FKBPL and AD-01 bind to the CD44 receptor and inhibit tumour cell migration in a CD44 dependant manner; CD44 knockdown abrogated AD-01 binding as well as its anti-migratory activity. Interestingly, FKBPL overexpression and knockdown or treatment with AD-01, regulated CD44 expression, suggesting a co-regulatory pathway for these two proteins. Downstream of CD44, alterations in the actin cytoskeleton, indicated by intense cortical actin staining and a lack of cell spreading and communication were observed following treatment with AD-01, explaining the anti-migratory phenotype. Concomitantly, AD-01 inhibited Rac-1 activity, up-regulated RhoA and the actin binding proteins, profilin and vinculin. Thus the anti-angiogenic protein, FKBPL, and AD-01, offer a promising and alternative approach for targeting both CD44 positive tumours and vasculature networks.
Resumo:
PURPOSE: FKBPL and its peptide derivative, AD-01, have already demonstrated tumour growth inhibition and CD44 dependent anti-angiogenic activity. Here we explore the ability of AD-01 to target CD44 positive breast cancer stem cells (BCSCs). EXPERIMENTAL DESIGN: Mammosphere assays and flow cytometry were utilized to analyse the effect of FKBPL overexpression/knockdown and AD-01 treatment ± other anti-cancer agents on BCSCs using breast cancer cell lines (MCF-7/MDA-231/ZR-75), primary patient samples and xenografts. Delays in tumour initiation were evaluated in vivo. The anti-stem cell mechanisms were determined using clonogenic assays, qPCR and immunofluorescence. RESULTS: AD-01 treatment was highly effective at inhibiting the BCSC population by reducing mammosphere forming efficiency (MFE) and ESA+/CD44+/CD24- or ALDH+ cell subpopulations in vitro and tumour initiation in vivo. The ability of AD-01 to inhibit the self-renewal capacity of BCSCs was confirmed; mammospheres were completely eradicated by the third generation. The mechanism appears to be due to AD-01-mediated BCSC differentiation demonstrated by a significant decrease in the number of holoclones and an associated increase in meroclones/paraclones; the stem cell markers, Nanog, Oct4 and Sox2, were also significantly reduced. Furthermore, we demonstrated additive inhibitory effects when AD-01 was combined with the Notch inhibitor, DAPT. AD-01 was also able to abrogate a chemo- and radiotherapy induced enrichment in BCSCs. Finally, FKBPL knockdown led to an increase in Nanog/Oct4/Sox2 and an increase in BCSCs, highlighting a role for endogenous FKBPL in stem cell signalling. CONCLUSIONS: AD-01 has dual anti-angiogenic and anti-BCSC activity which will be advantageous as this agent enters clinical trial.
Resumo:
Neurodegenerative diseases affecting the macula constitute a major cause of incurable vision loss and exhibit considerable clinical and genetic heterogeneity, from early-onset monogenic disease to multifactorial late-onset age-related macular degeneration (AMD). As part of our continued efforts to define genetic causes of macular degeneration, we performed whole exome sequencing in four individuals of a two-generation family with autosomal dominant maculopathy and identified a rare variant p.Glu1144Lys in Fibrillin 2 (FBN2), a glycoprotein of the elastin-rich extracellular matrix (ECM). Sanger sequencing validated the segregation of this variant in the complete pedigree, including two additional affected and one unaffected individual. Sequencing of 192 maculopathy patients revealed additional rare variants, predicted to disrupt FBN2 function. We then undertook additional studies to explore the relationship of FBN2 to macular disease. We show that FBN2 localizes to Bruch's membrane and its expression appears to be reduced in aging and AMD eyes, prompting us to examine its relationship with AMD. We detect suggestive association of a common FBN2 non-synonymous variant, rs154001 (p.Val965Ile) with AMD in 10,337 cases and 11,174 controls (OR=1.10; p-value=3.79×10(-5)). Thus, it appears that rare and common variants in a single gene - FBN2 - can contribute to Mendelian and complex forms of macular degeneration. Our studies provide genetic evidence for a key role of elastin microfibers and Bruch's membrane in maintaining blood-retina homeostasis and establish the importance of studying orphan diseases for understanding more common clinical phenotypes.
Resumo:
FK506-binding protein-like (FKBPL) has established roles as an anti-tumor protein, with a therapeutic peptide based on this protein, ALM201, shortly entering phase I/II clinical trials. Here, we evaluated FKBPL's prognostic ability in primary breast cancer tissue, represented on tissue microarrays (TMA) from 3277 women recruited into five independent retrospective studies, using immunohistochemistry (IHC). In a meta-analysis, FKBPL levels were a significant predictor of BCSS; low FKBPL levels indicated poorer breast cancer specific survival (BCSS) (hazard ratio (HR) = 1.30, 95% confidence interval (CI) 1.14-1.49, p < 0.001). The prognostic impact of FKBPL remained significant after adjusting for other known prognostic factors (HR = 1.25, 95% CI 1.07-1.45, p = 0.004). For the sub-groups of 2365 estrogen receptor (ER) positive patients and 1649 tamoxifen treated patients, FKBPL was significantly associated with BCSS (HR = 1.34, 95% CI 1.13-1.58, p < 0.001, and HR = 1.25, 95% CI 1.04-1.49, p = 0.02, respectively). A univariate analysis revealed that FKBPL was also a significant predictor of relapse free interval (RFI) within the ER positive patient group, but it was only borderline significant within the smaller tamoxifen treated patient group (HR = 1.32 95% CI 1.05-1.65, p = 0.02 and HR = 1.23 95% CI 0.99-1.54, p = 0.06, respectively). The data suggests a role for FKBPL as a prognostic factor for BCSS, with the potential to be routinely evaluated within the clinic.
Resumo:
OBJECTIVE: The antitumor effects of FK506-binding protein like (FKBPL) and its extracellular role in angiogenesis are well characterized; however, its role in physiological/developmental angiogenesis and the effect of FKBPL ablation has not been evaluated. This is important as effects of some angiogenic proteins are dosage dependent. Here we evaluate the regulation of FKBPL secretion under angiogenic stimuli, as well as the effect of FKBPL ablation in angiogenesis using mouse and zebrafish models.
APPROACH AND RESULTS: FKBPL is secreted maximally by human microvascular endothelial cells and fibroblasts, and this was specifically downregulated by proangiogenic hypoxic signals, but not by the angiogenic cytokines, VEGF or IL8. FKBPL's critical role in angiogenesis was supported by our inability to generate an Fkbpl knockout mouse, with embryonic lethality occurring before E8.5. However, whilst Fkbpl heterozygotic embryos showed some vasculature irregularities, the mice developed normally. In murine angiogenesis models, including the ex vivo aortic ring assay, in vivo sponge assay, and tumor growth assay, Fkbpl(+/-) mice exhibited increased sprouting, enhanced vessel recruitment, and faster tumor growth, respectively, supporting the antiangiogenic function of FKBPL. In zebrafish, knockdown of zFkbpl using morpholinos disrupted the vasculature, and the phenotype was rescued with hFKBPL. Interestingly, this vessel disruption was ineffective when zcd44 was knocked-down, supporting the dependency of zFkbpl on zCd44 in zebrafish.
CONCLUSIONS: FKBPL is an important regulator of angiogenesis, having an essential role in murine and zebrafish blood vessel development. Mouse models of angiogenesis demonstrated a proangiogenic phenotype in Fkbpl heterozygotes.
Resumo:
Peptidyl prolyl isomerases (PPIases) are proteins belonging to the immunophilin family and are characterised by their cis-trans isomerization activity at the X-Pro peptide bond, in addition to their tetratricopeptide repeat (TPR) domain, important for interaction with the molecular chaperone, Hsp90. Due to this unique structure these proteins are able to facilitate protein-protein interactions which can impact significantly on a range of cellular processes such as cell signalling, differentiation, cell cycle progression, metabolic activity and apoptosis. Malfunction and/or dysregulation of most members of this class of proteins promotes cellular damage and tissue/organ failure, predisposing to ageing and age-related diseases. Many individual genes within the PPIase family are associated with several age-related diseases including cardiovascular diseases (CVDs), atherosclerosis, type II diabetes (T2D), chronic kidney disease (CDK), neurodegeneration, cancer and age-related macular degeneration (AMD), in addition to the ageing process itself. This review will focus on the different roles of PPIases, and their therapeutic/biomarker potential in these age-related vascular diseases.
Resumo:
Aim of the study
This paper presents the experiences of undergraduate nursing students who participated in a creative learning project to explore the cells, tissues and organs of the human body through felt making.
Context and Background
This project was funded by a Teaching Innovation Award from the School of Nursing and Midwifery, Queen’s University Belfast to explore creative ways of engaging year one undergraduate nursing students in learning anatomy and physiology. The project was facilitated through collaboration between University Teaching staff and Arts Care, a unique arts and health charity in Northern Ireland.
Methodology
Twelve year one students participated in four workshops designed to explore the cells, tissues and organs of the human body through the medium of felt. Facilitated by an Arts Care artist, students translated their learning into striking felt images. The project culminated in the exhibition of this unique collection of work which has been viewed by fellow students, teaching staff, nurses from practice, and artists from Arts Care, friends, family and members of the public.
Key Findings and conclusions
The opportunity to learn in a more diverse way within a safe and non-judgmental environment was valued, with students’ reporting a greater confidence in life science knowledge. Self- reflection and group discussion revealed that the project was a unique creative learning experience for all involved – students, teaching staff and artist – resulting in individual and collective benefits far beyond knowledge acquisition. As individuals we each felt respected and recognised for our unique contribution to the project. Working in partnership with Arts Care enabled us to experience the benefits of creativity to well-being and reflect upon how engagement in creative activities can help healthcare professionals to focus on the individual patient’s needs and how this is fundamental to enhancing patient-centred care