775 research outputs found
The Experience of Adults with Chronic Stroke who have Participated in Occupation-Based or Modified Constraint Induced Interventions as a Part of a Research Study
There is a lack of qualitative research about the client perspective of specific chronic stroke interventions for motor recovery. The purpose of this phenomenological study was to understand the experiences of adults with chronic stroke who have participated in occupation-based (OBP) or modified constraint-induced (MCIT) interventions as a part of a research study. Four participants were recruited through convenience sampling and interviewed about their participation in research. Interviews were audio recorded, transcribed, and analyzed until themes emerged. Results showed participants engaged in the research interventions because of a desire to achieve a lost sense of ‘normalcy’ and perceptions of their outcomes were dependent on the type of intervention received (OBP or MCIT). Therapists can use knowledge of effective interventions, resiliency of clients, and their own therapeutic use of self to increase hope and motivation in recovery
Application Of Antenna Synthesis And Digital Signal Processing Techniques For Active Millimeter-wave Imaging Systems
Millimeter-wave imaging has gathered attention in recent years for its ability to penetrate clothing, thin layers of soils, and certain construction materials. However, image quality remains a challenge that needs to be addressed. One way of improving image quality is by increasing the dimensions of the collecting aperture. A sparse array can be used to synthesize a larger aperture with a limited set of relatively small detectors. In this research we design, build, and test a test-bed having an active source at 94 GHz and an array of coherent detectors, mounted on arms that extend radially on a rotary table. Using this test bed a circular area with a maximum diameter of 900 mm can be scanned. The signal is down-converted using heterodyne receivers with digital in-phase and quadrature detection. Signal correlation is performed using the digitized data, which is stored for post-processing, electronic focusing, and image reconstruction. Near-field imaging using interferometric reconstructions is achieved using electronic focusing. Imaging tests show the ability of the system to generate imagery of concealed and unconcealed objects at distances between 400 and 700 mm. A study of the effects of redundant and nonredundant configurations on image quality for 4 common detector configurations is presented. In this document we show that an active sparse-aperture imaging system using digital correlators is a viable way to generate millimeter-wave images
Competition between condensation of monovalent and multivalent ions in DNA aggregation
We discuss the distribution of ions around highly charged PEs when there is
competition between monovalent and multivalent ions, pointing out that in this
case the number of condensed ions is sensitive to short-range interactions,
salt, and model-dependent approximations. This sensitivity is discussed in the
context of recent experiments on DNA aggregation, induced by multivalent
counterions such as spermine and spermidine.Comment: 6 pages, 1 figur
Role of the ASPP Family in the Regulation of p53-Mediated Apoptotic Death of Retinal Ganglion Cells after Optic Nerve Injury
Le glaucome est la première cause de cécité irréversible à travers le monde. À présent il n’existe aucun remède au glaucome, et les thérapies adoptées sont souvent inadéquates. La perte de vision causée par le glaucome est due à la mort sélective des cellules rétiniennes ganglionnaires, les neurones qui envoient de l’information visuelle de la rétine au cerveau. Le mécanisme principal menant au dommage des cellules rétiniennes ganglionnaires lors du glaucome n’est pas bien compris, mais quelques responsables putatifs ont été proposés tels que l’excitotoxicité, le manque de neurotrophines, la compression mécanique, l’ischémie, les astrocytes réactifs et le stress oxidatif, parmis d’autres. Indépendamment de la cause, il est bien établi que la perte des cellules rétiniennes ganglionnaires lors du glaucome est causée par la mort cellulaire programmée apoptotique. Cependant, les mécanismes moléculaires précis qui déclenchent l’apoptose dans les cellules rétiniennes ganglionnaires adultes sont mal définis. Pour aborder ce point, j’ai avancé l’hypothèse centrale que l’identification de voies de signalisations moléculaires impliquées dans la mort apoptotique des cellules rétiniennes ganglionnaires offrirait des avenues thérapeutiques pour ralentir ou même prévenir la mort de celles-ci lors de neuropathies oculaires telles que le glaucome.
Dans la première partie de ma thèse, j’ai caractérisé le rôle de la famille de protéines stimulatrices d’apoptose de p53 (ASPP), protéines régulatrices de la famille p53, dans la mort apoptotique des cellules rétiniennes ganglionnaires. p53 est un facteur de transcription nucléaire impliqué dans des fonctions cellulaires variant de la transcription à l’apoptose. Les membres de la famille ASPP, soit ASPP1, ASPP2 et iASPP, sont des protéines de liaison de p53 qui régulent l’apoptose. Pourtant, le rôle de la famille des ASPP dans la mort des cellules rétiniennes ganglionnaires est inconnu. ASPP1 et ASPP2 étant pro-apoptotiques, l’hypothèse de cette première étude est que la baisse ciblée de ASPP1 et ASPP2 promouvrait la survie des cellules rétiniennes ganglionnaires après une blessure du nerf optique. Nous avons utilisé un modèle expérimental bien caractérisé de mort apoptotique neuronale induite par axotomie du nerf optique chez le rat de type Sprague Dawley. Les résultats de cette étude (Wilson et al. Journal of Neuroscience, 2013) ont démontré que p53 est impliqué dans la mort apoptotique des cellules rétiniennes ganglionnaires, et qu’une baisse ciblée de ASPP1 et ASPP2 par acide ribonucléique d’interference promeut la survie des cellules rétiniennes ganglionnaires.
Dans la deuxième partie de ma thèse, j’ai caractérisé le rôle d’iASPP, le membre anti-apoptotique de la famille des ASPP, dans la mort apoptotique des cellules rétiniennes ganglionnaires. L’hypothèse de cette seconde étude est que la surexpression d’iASPP promouvrait la survie des cellules rétiniennes ganglionnaires après axotomie. Mes résultats (Wilson et al. PLoS ONE, 2014) démontrent que le knockdown ciblé de iASPP exacerbe la mort apoptotique des cellules rétiniennes ganglionnaires, et que la surexpression de iASPP par virus adéno-associé promeut la survie des cellules rétiniennes ganglionnaires.
En conclusion, les résultats présentés dans cette thèse contribuent à une meilleure compréhension des mécanismes régulateurs sous-jacents la perte de cellules rétiniennes ganglionnaires par apoptose et pourraient fournir des pistes pour la conception de nouvelles stratégies neuroprotectrices pour le traitement de maladies neurodégénératives telles que le glaucome.Glaucoma is the leading cause of irreversible blindness worldwide. At present, there is no cure for glaucoma, and current therapies are often inadequate. Loss of vision in glaucoma results from the death of retinal ganglion cells, the neurons that send visual information from the retina to the brain. The principal mechanism leading to retinal ganglion cell damage during glaucoma is not well understood, however, putative culprits have been proposed including excitotoxicity, neurotrophin deprivation, mechanical compression, ischemia, reactive astrocytes and oxidative stress. It is well established that retinal ganglion cell loss during glaucoma is caused by apoptotic programmed cell death, however, the precise mechanisms that lead to apoptotic death of adult retinal ganglion cells are poorly defined. To address this point, I put forth the central hypothesis that the identification of signaling pathways involved in apoptotic retinal ganglion cell death would offer therapeutic avenues to slow or prevent retinal ganglion cell death during ocular neuropathies such as glaucoma.
In the first part of my thesis, I characterised the role of Apoptosis Stimulating Protein of p53 family (ASPP) proteins, which are regulators of p53, in the apoptotic death of retinal ganglion cells. p53 is a nuclear transcription factor implicated in cellular functions ranging from transcription to apoptosis. ASPP family members ASPP1, ASPP2 and iASPP are p53 binding proteins that belong to a family of protein regulators of p53-dependent apoptotic death. However, the role of ASPP family members in retinal ganglion cell death is unknown. As ASPP1 and ASPP2 are pro-apoptotic, the hypothesis of our first study was that the knockdown of ASPP1 and ASPP2 gene expression would lead to retinal ganglion cell survival after an optic nerve lesion. We used a well-characterized experimental model of neuronal apoptosis induced by optic nerve axotomy in Sprague Dawley rats. The results of this study (Wilson et al. Journal of Neuroscience, 2013) demonstrated that p53 is implicated in retinal ganglion cell death, and that targeted knockdown of ASPP1 and ASPP2 by short interference ribonucleic acid promotes retinal ganglion cell survival. The knockdown of ASPP2 correlates with a reduction in the levels of pro-apoptotic p53 regulated targets PUMA and Fas/CD95.
In the second part of my thesis, I characterized the role of the anti-apoptotic member of the ASPP family, iASPP, in the apoptotic death of retinal ganglion cells. The hypothesis of this second study is that the overexpression of iASPP would promote retinal ganglion cell survival after axotomy. The data (Wilson et al. PLoS ONE, 2014) demonstrate that the targeted knockdown of iASPP by short interference ribonucleic acid exacerbates retinal ganglion cell death, and that the overexpression of iASPP by adeno-associated virus promotes retinal ganglion cell survival. The overexpression of iASPP correlates with a reduction in protein levels of PUMA and Fas/CD95.
In conclusion, the findings presented in this thesis contribute to a better understanding of the pathological mechanisms underlying retinal ganglion cell loss by apoptosis and might provide insights into the design of novel neuroprotective treatments for neurodegenerative diseases such as glaucoma
Empleo de lixiviados para compostar los residuos sólidos orgánicos domiciliarios de la ciudad de Sucúa, mediante las técnicas de takakura y de vermicompostaje.
El objetivo principal fue emplear lixiviados para compostar los residuos sólidos orgánicos domiciliarios de la ciudad de Sucúa, mediante las Técnicas de Takakura y Vermicompostaje para su posible utilización en la agricultura. Para esta investigación, se armaron diez camas, todas contenían 100 kg de residuos orgánicos. Los tratamientos correspondientes al método Takakura, estaban constituídos por: aserrín (11.06 kg) y semilla Takakura (20 kg), mientras que los tratamientos del vermicompostaje sólo contenían residuos orgánicos. Los lixiviados utilizados fueron recogidos del drenaje de la planta de lombricultura. La elaboración del compost se lo realizó en estructuras de trincheras, durante el proceso se realizó un control diario de temperatura, pH y humedad, además después de cada volteo se tomó una muestra representativa de cada tratamiento para realizar análisis de la evolución del proceso de compostaje. La evolución de las temperaturas de las camas fue adecuada, al inicio se presentó la fase mesófila, para seguidamente dar inicio a la fase termófila alcanzando temperaturas mayores a 55 °C, mismas que fueron controladas con volteos manuales. Una vez finalizado el proceso se verificó la calidad del abono mediante análisis físicos-químicos, químicos y biológicos, mismos que se encontraron dentro de los rangos establecidos por normativas como la Agencia de Protección Ambiental (EPA) y de la Comisión Europea. De acuerdo al análisis estadístico, el mejor tratamiento fue el TKL3, presentando un porcentaje de Índice Germinación de 71% indicativo de ausencia de fitotoxicicidad, la relación C/N equivalente a 14.3 y conductividad eléctrica de 2.35 mS/cm lo cual demostró la calidad del producto final. El vermicompostaje permitió obtener una elevada concentración de biomasa. Se recomienda emplear el método Takakura con una adición de lixiviado de 375 ml para un óptimo tratamiento de residuos orgánicos.The main objective was to find leachates to check the organic solid residues of the city of Sucúa, using the techniques of Takakura and Vermicomposting for its possible use in agriculture. For this investigation ten beds were assembled, all containing 100 kg of organic waste. The treatments corresponding to the Takakura method consisted of: sawdust (11.06 kg) and Takakura seed (20 kg), while the Vermicomposting treatments only contained organic residues. The leachates used were collected from the drainage of the Vermiculture plant. The elaboration of the compost was carried out in trench structures, during the process a daily temperature, pH and humidity control was carried out, besides, after each flip, a representative sample of each treatment was taken to analyze the evolution of the composting process. The evolution of the temperatures of the beds was adequate, at the beginning the mesophilic phase was presented, to then start the thermophilic phase reaching temperatures higher than 55 ° C, which were controlled with manual turning. Once the process was completed, the quality of the fertilizer was verified by the physical-chemical, chemical and chemical analysis, as well as biological, which were found within the ranges established by regulations such as the Environmental Protection Agency (EPA) and the European Commission. According to the statistical analysis, the best treatment was TKL3, presenting a percentage of germination index of 71% indicative of absence of phytotoxicity, the C / N ratio equivalent to 14.3 and electrical conductivity of 2.35 mS / cm which demonstrated the quality of the final product. Vermicomposting and obtain a concentration of biomass. It is recommended to use the Takakura method with a 375 ml leachate addition for a correct treatment of organic waste
Análisis de las herramientas pedagógicas que inciden en el desarrollo del aprendizaje autónomo en estudiantes con diversidad funcional en la UNAD - CEAD Sogamoso, en el área de Psicología
Este documento presenta los resultados del trabajo de grado realizado en la modalidad de proyecto de investigación bajo la asesoría del doctor: NUMAR ALVAREZ CARDONA inscrito en la línea de investigación cualitativa y cuantitativa de la ECDU y que se basa en la metodología de educación a distancia y se realizó en el CEAD de Sogamoso.This document presents the results of the degree work carried out in the research project mode under the advice of the doctor: NUMAR ALVAREZ CARDONA enrolled in the qualitative and quantitative research line of the ECDU and which is based on the methodology of distance education and It was carried out in the CEAD of Sogamoso
Producción y calidad de forraje con enmiendas orgánicas en pastura (Brachiaria Brizantha), en la Costa Caribe Sur de Nicaragua
In this research, different organic alternatives have been applied to determine their effects on forage's production and quality in Brachiaria brizantha. The study evaluated three types of organic amendments (Lombrizhumus, Bokashi and EM) in the Brachiaria brizantha grass, which were compared with a witness treatment (no organic amendment). A completely randomized block design (BCA) was used, 4 replicates per treatment for a total of 16 plots, evaluated in established pastures. The highest production of green biomass is 17.325 kg/ha when applying lombrihumus; in dry matter production lombrihumus obtained the highest yield (3.383 kg/ha). The largest length of primary roots was obtained by applying lombrihu- mus (17.25 cm). In the leaf/stem ratio variable the greatest results were obtained with Lombrihumus; With Bokashi were obtained the highest percentage of dry matter digestibility (62%), crude protein (9.8%) and ash (9.52%). Lombrihumus and bokashi had the greatest effects on the variables evaluated in Brachiaria brizantha. The use of organic alternatives is recommended to optimize the production and quality of the Brachiaria brizantha pasture.Esta investigación se ha aplicado diferentes alternativas orgánicas para determinar sus efectos en la producción y calidad de forraje en Brachiaria brizantha. En el estudio se evaluaron tres tipos de enmiendas orgánicas (Lombrihumus, Bokashi y EM) en el pasto Brachiaria brizantha, las que fueron comparados con un tratamiento testigo (sin enmienda orgánica). Se empleó un diseño de bloque completamente al azar (BCA), 4 réplicas por tratamiento para un total de 16 parcelas, evaluado en pasturas ya establecidas. La mayor producción de biomasa verde es de 17,325 kg/ha al aplicar lombrihumus, en producción de materia seca el lombrihumus obtuvo el mayor rendimiento (3,383 kg/ha). La mayor longitud de raíces primarias se obtuvo al aplicar lombrihumus (17.25 cm). En la variable relación hoja/tallo los mayores resultados se obtuvieron con Lombrihumus. Con bokashi se obtuvieron los mayores porcentajes de digestibilidad de la materia seca (62%), proteína bruta (9.8%) y cenizas (9.52%). El lombrihumus y bokashi ejercieron los mayores efectos en las variables evaluadas en Brachiaria brizantha. Se recomienda el uso de alternativas orgánicas para optimizar la producción y calidad de la pastura Brachiaria brizantha
GRAIL-identified gravity anomalies in Oceanus Procellarum:Insight into subsurface impact and magmatic structures on the Moon
Four, quasi-circular, positive Bouguer gravity anomalies (PBGAs) that are similar in diameter (~90–190 km) and gravitational amplitude (>140 mGal contrast) are identified within the central Oceanus Procellarum region of the Moon. These spatially associated PBGAs are located south of Aristarchus Plateau, north of Flamsteed crater, and two are within the Marius Hills volcanic complex (north and south). Each is characterized by distinct surface geologic features suggestive of ancient impact craters and/or volcanic/plutonic activity. Here, we combine geologic analyses with forward modeling of high-resolution gravity data from the Gravity Recovery and Interior Laboratory (GRAIL) mission in order to constrain the subsurface structures that contribute to these four PBGAs. The GRAIL data presented here, at spherical harmonic degrees 6–660, permit higher resolution analyses of these anomalies than previously reported, and reveal new information about subsurface structures. Specifically, we find that the amplitudes of the four PBGAs cannot be explained solely by mare-flooded craters, as suggested in previous work; an additional density contrast is required to explain the high-amplitude of the PBGAs. For Northern Flamsteed (190 km diameter), the additional density contrast may be provided by impact-related mantle uplift. If the local crust has a density ~2800 kg/m3, then ~7 km of uplift is required for this anomaly, although less uplift is required if the local crust has a lower mean density of ~2500 kg/m3. For the Northern and Southern Marius Hills anomalies, the additional density contrast is consistent with the presence of a crustal complex of vertical dikes that occupies up to ~50% of the regionally thin crust. The structure of Southern Aristarchus Plateau (90 km diameter), an anomaly with crater-related topographic structures, remains ambiguous. Based on the relatively small size of the anomaly, we do not favor mantle uplift; however, understanding mantle response in a region of especially thin crust needs to be better resolved. It is more likely that this anomaly is due to subsurface magmatic material given the abundance of volcanic material in the surrounding region. Overall, the four PBGAs analyzed here are important in understanding the impact and volcanic/plutonic history of the Moon, specifically in a region of thin crust and elevated temperatures characteristic of the Procellarum KREEP Terrane
Onset of DNA Aggregation in Presence of Monovalent and Multivalent Counterions
We address theoretically aggregation of DNA segments by multivalent
polyamines such as spermine and spermidine. In experiments, the aggregation
occurs above a certain threshold concentration of multivalent ions. We
demonstrate that the dependence of this threshold on the concentration of DNA
has a simple form. When the DNA concentration c_DNA is smaller than the
monovalent salt concentration, the threshold multivalent ion concentration
depends linearly on c_DNA, having the form alpha c_DNA + beta. The coefficients
alpha and beta are related to the density profile of multivalent counterions
around isolated DNA chains, at the onset of their aggregation. This analysis
agrees extremely well with recent detailed measurements on DNA aggregation in
the presence of spermine. From the fit to the experimental data, the number of
condensed multivalent counterions per DNA chain can be deduced. A few other
conclusions can then be reached: i) the number of condensed spermine ions at
the onset of aggregation decreases with the addition of monovalent salt; ii)
the Poisson-Boltzmann theory over-estimates the number of condensed multivalent
ions at high monovalent salt concentrations; iii) our analysis of the data
indicates that the DNA charge is not over-compensated by spermine at the onset
of aggregation.Comment: 12 pages, 8 figures. Biophysical Journal 2003, in pres
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