287 research outputs found

    Implications of tree management on poplar and willow pasture-tree systems : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Plant Science, Massey University, Palmerston North, New Zealand

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    Willow and poplar trees planted at wide spacing have proved their effectiveness as a biological method to control soil erosion in pastoral hill country. Due to lack of management, many trees aged 30+ years have grown very large (>60 cm diameter at breast height), resulting in excessive shading of understorey pasture. The large trees are also prone to breakage of branches and toppling during strong winds, potentially damaging farm infrastructure or injuring livestock. Management of tree size can coincide with providing edible poplar and willow foliage as a source of supplementary fodder in summer droughts. Trees can be pollarded, involving total canopy removal, but the effects of pollarding on tree root dynamics are poorly understood. This thesis evaluated the effect of the tree canopy removal on the root dynamics and root non-structural carbohydrate dynamics of pollarded mature willow and poplar trees and decapitated young willow and poplar trees grown from cuttings. Impacts of tree canopy removal when trees were at different phenological stages were also studied in pollarded mature willow trees and decapitated young willow and poplar trees. Finally, herbage accumulation under pollarded trees was contrasted with herbage accumulated under unpollarded (UP) trees and in open pasture sites (OP) away from direct tree influence. Pollarding did not impose a unique impact on the root structure of mature willow and poplar trees. However some similarities were found in both species. For instance, pollarding had its main impact in the roots closest to the trunk and above 300 mm soil depth. In these root sections disrupted by pollarding, fine root length and mass of pollarded (P) trees were, one year after above-ground removal, from 2× to 4× less than equivalent unpollarded (UP) trees. However, one year after pollarding, pollarded trees recovered or maintained the initial fine root densities recorded in the same trees prior to pollarding. The study conducted with young willow and poplar trees grown from cuttings showed that willow trees had a greater ability to recover from damage in the root structure after decapitation. Nine months after decapitation in early autumn, root mass of young willow decapitated trees was 57% greater than prior to decapitation and 64% less than non-decapitated (ND) trees. In contrast, within the same time frame, root mass of young poplar trees decapitated in early autumn was 80% less than ND trees and 52% less than the initial root mass recorded prior to decapitation. Greater resprouting ability of willow trees than poplar trees after decapitation was proposed as the cause for the greater resilience to decapitation observed in willow trees than in poplar ones. Further evidence for a greater resilience to pollarding of willow trees was found in the root starch dynamics evaluated after tree canopy removal. Pollarded or decapitated willow trees (mature or grown from cuttings) were able to replenish their root starch concentrations similarly to UP or ND trees in the growing season following tree canopy removal. In contrast, both pollarded and decapitated poplar trees (mature or grown from cuttings) had lesser root starch concentrations than intact trees one year after tree canopy removal. Pollarding (P) or decapitation (D) at dormancy (DP or DD trees) showed no clear advantages in terms of the tree root structure maintenance or recovery after above-ground removal, over pollarding or decapitating the trees towards the end of the growing season in early autumn (AP or AD trees), when trees still had leaves. With mature willow trees, annual average fine root density (fRD) recovery of DP trees relative to pre-pollarding density was greater than annual average fRD recovery of AP trees. However, this difference was attributed to record moisture restrictions that disrupted the root growth of both AP and UP trees during the growing season following early autumn pollarding. Similarly, young DD and AD willow and poplar trees showed that four and a half months after decapitation, both treatment trees were able to recover or maintain initial root mass recorded prior to decapitation. The study on herbage accumulation beneath pollarded trees, suggests that 4 years after being pollarded, P willow trees shaded pasture in a similar way to UP trees, as annual net herbage accumulation (NHA) attained in these two environments was statistically not different. Annual NHA under P and UP environments, were, respectively, 30 and 43% less than annual net herbage accumulation recorded in open pasture sites (4.9 t DM ha-1 yr -1). Ability of willow trees to recover, within the first year after pollarding or decapitation, initial root densities recorded prior to canopy removal, and to replenish root starch concentration similar to intact trees, suggests these trees could have pollarding cycles of 2 to 3 years. Short pollarding cycles could lessen herbage accumulation reductions on a pasture-tree stand level as more trees or more frequent repollarding is practised. However, results derived in this thesis from willow trees, need to be confirmed in at least two year lasting studies before recommending shorter pollarding cycles than currently advised of 3 or 4 years. In contrast, poplar trees require longer pollarding cycles or higher tree stand densities if a pollarding program is instituted, as these trees were not able to recover within the first year after canopy removal, the root values recorded prior to pollarding and/or to replenish the root starch reserves

    Características clínico epidemiológicas de las infecciones asociadas a la atención de salud en un hospital pediátrico de referencia nacional 2014 al 2018, en Lima-Perú

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    Determina las características clínico epidemiológicas de las infecciones asociadas a la atención de salud (IAAS) en un hospital público de referencia nacional, 2014 - 2018, Lima, Perú. El estudio es descriptivo. Se revisó las historias clínicas y registros de vigilancia de infecciones. La muestra estuvo conformada por 171 historias clínicas que cumplieron los criterios de inclusión que tuvieron al menos una IAAS. Se utilizó como instrumento una ficha elaborada en base a ficha de recolección de datos del estudio de prevalencia de IIH del MINSA. Se obtuvo que el 56.7% de las infecciones ocurrió en sexo masculino y el grupo de edad más afectado fueron los menores de 1 año (45.6%). Respecto a las características de los casos con IAAS, la mayoría fueron pacientes distróficos (56.1%); el motivo de hospitalización fue compromiso del SNC, seguido de causa cardiovascular, gastrointestinal y enfermedades respiratorias; recién nacidos (RN) con peso de 1500 a < de 2500 gr. Los antimicrobianos más usados fueron la Vancomicina (74.3%), el Meropenem (60.8%) y la ceftazidima (15.2%). La mortalidad más elevada fue en las Neumonías asociadas a ventilador mecánico (NAVM) con 32.2%. En cuanto a las características epidemiológicas: el servicio con mayor número de pacientes fue Neurocirugía, la mayoría tuvo una estancia de 31 a más días (92.4%); la mitad de los casos de IAAS tuvieron menos de 19 días de exposición a un procedimiento invasivo. La densidad de incidencia de Ventriculitis fue de 4.5 x 1000 días uso de drenaje ventricular externo (DVE); Infección del torrente sanguíneo entre 0.5 y 6.4 x 1000 días uso catéter venoso central; NAVM entre 1.5 y 15.2 x 1000 días uso de VM, y para las Infecciones del tracto urinario entre 0 y 4 x 1000 días uso de catéter urinario permanente (CUP). El 89.4% de las IAAS correspondió a Ventriculitis asociada a DVE, el 74.4% a ITS asociado a catéter venoso central de inserción periférica, 64.5% a neumonía asociada a VM, 34.7% a ITS asociada a CVC y 20.7% a Infección urinaria asociada a CUP. Los gérmenes aislados fueron: P. aeruginosa (26.9%) y K. pneumoniae (9.9%). En conclusión, las IAAS fueron más frecuentes en el menor de un año, sexo masculino y una estancia hospitalaria larga. Las neumonías asociadas a ventilación mecánica tienen una densidad de incidencia baja, pero alta proporción de pacientes y alta mortalidad

    Percepción del adolescente sobre la calidad de atención que brinda el profesional de enfermería en los servicios de medicina del Instituto Nacional de Salud del Niño, 2009

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    Objetivos: Determinar la percepción del adolescente sobre la calidad de la atención que brinda el profesional de enfermería en los servicios de Medicina en el INSN, 2009 e Identificar la percepción la según la dimensión humana, técnica y entorno. Material y Métodos. El estudio es de nivel aplicativo, tipo cuantitativo, método descriptivo, prospectivo, de corte transversal. La población estuvo conformada por adolescentes hospitalizados en los servicios de Medicina. La técnica fué la entrevista considerando el asentimiento informado y el instrumento una escala modificada tipo Lickert. Resultados. Del 100% (36), 72% (26) tuvieron percepción medianamente favorable, 14% (5) desfavorable, 14% (5) favorable. En cuanto a la dimensión humana 50% (18) es medianamente favorable, 28% (10) desfavorable y 22% (8) favorable; en la dimensión técnica 53% (19) es medianamente favorable, 30% (11) desfavorable y 17% (6) favorable y en la dimensión entorno 39% (14) tienen percepción desfavorable, 33% (12) medianamente favorable y 28% (10) favorable. Conclusiones. La mayoría tienen una percepción medianamente favorable a desfavorable sobre la calidad de atención que brinda el profesional de enfermería referido a que perciben que lo atienden rápido cuando sienten dolor, tienen miedos o temor antes de un procedimiento, está pendiente por las molestias posterior a un procedimiento, se preocupa porque tenga privacidad, por su alimentación y se comunica, y lo desfavorable está referido a que no informa las reglas del servicio ni verifica si lo entendió, es poco amable y cortante.Trabajo académic

    Diseño de enrocados de protección de la relavera La Esperanza – Río Tulumayo

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    Ilustra el diseño de enrocados de protección en el talud de la Relavera “La Esperanza” que está ubicada en la margen derecha de un tramo del río Tulumayo. Detalla los criterios de diseño y procedimiento a seguir para determinar el dimensionamiento de enrocados de protección en taludes pertenecientes a cauces naturales o artificiales.Trabajo de suficiencia profesiona

    Reseña sobre el concepto de inteligencia emocional y su importancia para consejeros, administradores, trabajadores sociales y educadores

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    Although in earlier ages a person’s intelligence was based on intellectual knowledge and the ability to strike high grades, in the 21st century this vision needs to be reformulated thanks to the study of emotional intelligence. Emotional intelligence, analyzed by many experts throughout history, is defined as the ability an individual archives to control and regulate their feelings, using them as a guide for thought and action. The present article revises a variety of literature, focusing in the components of emotional intelligence as well as the results reflected in individuals in all life stages. Aunque en épocas anteriores se consideraba la inteligencia de una persona a base de su conocimiento intelectual y capacidad para obtener altas calificaciones, en el siglo XXI esa visión se ve afectada ante el análisis del concepto de inteligencia emocional. La inteligencia emocional, estudiada por diversos expertos a través del tiempo, es definida como la capacidad del individuo para controlar y regular los sentimientos utilizándolos como guía del pensamiento y de la acción. El artículo presente explora diversos conceptos, enfatizando principalmente los componentes de la inteligencia emocional al igual que el reflejo de la misma en el individuo en todas las etapas de vida. 

    Screen Printable Electrochemical Capacitors on Flexible Substrates

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    This work presents a novel approach for the fabrication of Electrochemical Capacitors (ECs) based on the screen-printing of a commercial carbon-based conductive ink on flexible substrates. This technique enables the fast and cost-effective production of ECs with high flexibility and outstanding performance over bending states and voltage cycling, as demonstrated by means of cyclic voltammetry and galvanometric charge-discharge measurements. Despite the fact that the specific areal capacitances achieved are lower than the ones obtained using other carbon-based materials (~22 μF/cm2), the results show that, as soon as new screen-printable carbon-based pastes become available, this fabrication method will enable the mass production of ECs that can be attached to any surface as a conformal patch, as it is being required by a large number of the emerging technological applications.This work has been partially supported by the Spanish Ministry of Education, Culture and Sport (MECD) and the European Union through the pre-doctoral grant FPU16/01451, and its mobility program, the project TEC2017-89955-P and fellowship H2020-MSCA-IF-2017794885-SELFSENS

    Multipurpose Sensing Platform Based on Laser-Reduced Graphene Oxide for Flexible and Ubiquitous Electronics

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    We present a versatile sensing platform, intended for ubiquitous and flexible electronics sensing applications based on the controlled reduction of Graphene Oxide by a laser diode. This technique allows the fast and ecological production of reduced Graphene Oxide without the need of expensive lithography masks. We will show results of the conductivity calibration by the photothermal reduction power, as well as the electrical characterization of the bare samples. Finally, a simple demonstrator of the platform based on an ultra-low power System on Chip (SoC) is introduced.This work has been supported by the Spanish Ministry of Educaton, Culture and Sport (MECD) through the pre-doctoral grant FPU16/01451, the University of Granada through the scholarship “Initiation to Research“, the National Excellence Research Project TEC2017-89955-P and the European Union by the fellowship H2020-MSCA-IF-2017 794885-SELFSENS

    Low-Cost Energy-Autonomous Sensor Nodes Through RF Energy Harvesting and Printed Technology

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    The irruption of Internet of Things and 5G in our society comes along with several technological challenges to overcome. From an overall perspective, the low-cost and environmental friendliness of these technologies need to be ensured for their universal deployment in different areas, starting with the sensors and finishing with the power sources. To address these challenges, the production and maintenance of a great number of sensor nodes incur costs, which include manufacturing and integration in mass of elements and sub-blocks, changing or recharging of batteries, as well as management of natural resources and waste. In this article, we demonstrate how Radio Frequency Energy Harvesting (RFEH) and printed flexible technology (a growing technology for sensors) can solve these concerns through costeffective mass-production and utilization of energy harvesting for the development of energy-autonomous nodes, as part of a wireless sensor network. We present as illustration a sprayed flexible relative humidity sensor powered with RFEH under the store-and-use principle.This work was partially supported by the ECSEL Joint Undertaking through the Electronic Component Systems for European Leadership Joint Undertaking under grant agreement No 737434. This Joint Undertaking receives support from the German Federal Ministry of Education and Research and the European Union’s Horizon 2020 research and innovation program and Slovakia, Netherlands, Spain, Italy. In addition, the Spanish Ministry of Education, Culture and Sport (MECD) and the European Union supported it through the pre-doctoral grant FPU16/01451 and the fellowship H2020-MSCA-IF-2017794885-SELFSENS

    Flexible Laser-Reduced Graphene Oxide Thermistor for Ubiquitous Electronics

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    This work presents a versatile sensing platform, intended for ubiquitous and flexible electronics based on a laser reduced-Graphene-Oxide thermistor. This technique enables the fast and ecological production of reduced Graphene Oxide without the need of masks or expensive lithography processes. The final transducer is fabricated on a flexible plastic substrate in order to use it as a superficial patch. Finally, a full demonstrator, which integrates this flexible thermistor with a low power System on Chip with wireless transmission, is presented.This work has been partially supported by the Spanish Ministry of Education, Culture and Sport (MECD) through the pre-doctoral grant FPU16/01451 , the National Excellence Research Project TEC2017-89955-P and the University of Granada through the scholarship ”Initiation to Research
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