Diagnostic endoscopy of the navicular bursa using a needle endoscope by direct or transthecal approach: A comparative cadaver study

OBJECTIVES: To compare the practicability, visualization of structures, and iatrogenic damage of direct and transthecal approaches to the navicular bursa for diagnostic needle endoscopy. STUDY DESIGN: Descriptive study. SAMPLE POPULATION: Equine cadaver forelimbs (n = 30). METHODS: Direct and transthecal approaches for insertion of a needle endoscope into the navicular bursa were performed. Video recordings of endoscopic procedures were assessed to determine all structures visualized within the navicular bursa. Number of attempts to gain access to the navicular bursa and total time for insertion and examination were recorded. Distribution and severity of iatrogenic lesions were assessed and scored after dissection. RESULTS: There were no statistical differences for number of attempts or time needed for insertion and examination between direct and transthecal approaches. The direct approach offered significantly increased visibility of the ipsilateral abaxial and proximal margins of the navicular bone, and ipsilateral collateral sesamoidean ligament. Iatrogenic lesions were superficial and focal, regardless of approach taken, or whether a blunt or sharp trocar tip was used. CONCLUSIONS: The direct approach provided significantly better visualization of the ipsilateral structures within the navicular bursa compared to the transthecal approach. Needle endoscopy offers a reliable technique to evaluate the navicular bursa and may complement or replace other diagnostic modalities in horses with lameness localized to the navicular region.

In vitro differentiation of mouse granulocytes. Programmed Cell Death: Methods and Protocols

Granulocytes are central players of the immune system and, once activated, a tightly controlled balance between effector functions and cell removal by apoptosis guarantees maximal host benefit with least possible collateral damage to healthy tissue. Granulocytes are end-differentiated cells that cannot be maintained in culture for prolonged times. Isolating primary granulocytes is inefficient and challenging when working with mice, and especially so for the lowly abundant eosinophil and basophils subtypes. Here we describe an in vitro protocol to massively expand mouse derived myeloid progenitors and to differentiate them ‘on demand’ and in large numbers into mature neutrophils or basophils.

Lung Volume Reduction in Pulmonary Emphysema from the Radiologist's Perspective

Pulmonary emphysema causes decrease in lung function due to irreversible dilatation of intrapulmonary air spaces, which is linked to high morbidity and mortality. Lung volume reduction (LVR) is an invasive therapeutical option for pulmonary emphysema in order to improve ventilation mechanics. LVR can be carried out by lung resection surgery or different minimally invasive endoscopical procedures. All LVR-options require mandatory preinterventional evaluation to detect hyperinflated dysfunctional lung areas as target structures for treatment. Quantitative computed tomography can determine the volume percentage of emphysematous lung and its topographical distribution based on the lung's radiodensity. Modern techniques allow for lobebased quantification that facilitates treatment planning. Clinical tests still play the most important role in post-interventional therapy monitoring, but CT is crucial in the detection of postoperative complications and foreshadows the method's high potential in sophisticated experimental studies. Within the last ten years, LVR with endobronchial valves has become an extensively researched minimally-invasive treatment option. However, this therapy is considerably complicated by the frequent occurrence of functional interlobar shunts. The presence of "collateral ventilation" has to be ruled out prior to valve implantations, as the presence of these extraanatomical connections between different lobes may jeopardize the success of therapy. Recent experimental studies evaluated the automatic detection of incomplete lobar fissures from CT scans, because they are considered to be a predictor for the existence of shunts. To date, these methods are yet to show acceptable results. KEY POINTS Today, surgical and various minimal invasive methods of lung volume reduction are in use. Radiological and nuclear medical examinations are helpful in the evaluation of an appropriate lung area. Imaging can detect periinterventional complications. Reduction of lung volume has not yet been conclusively proven to be effective and is a therapeutical option with little scientific evidence.

Modifying Post-Operative Medical Care after EBV Implant May Reduce Pneumothorax Incidence.

OBJECTIVE Endoscopic lung volume reduction (ELVR) with valves has been shown to improve COPD patients with severe emphysema. However, a major complication is pneumothoraces, occurring typically soon after valve implantation, with severe consequences if not managed promptly. Based on the knowledge that strain activity is related to a higher risk of pneumothoraces, we asked whether modifying post-operative medical care with the inclusion of strict short-term limitation of strain activity is associated with a lower incidence of pneumothorax. METHODS Seventy-two (72) emphysematous patients without collateral ventilation were treated with bronchial valves and included in the study. Thirty-two (32) patients received standard post-implantation medical management (Standard Medical Care (SMC)), and 40 patients received a modified medical care that included an additional bed rest for 48 hours and cough suppression, as needed (Modified Medical Care (MMC)). RESULTS The baseline characteristics were similar for the two groups, except there were more males in the SMC cohort. Overall, ten pneumothoraces occurred up to four days after ELVR, eight pneumothoraces in the SMC, and only two in the MMC cohorts (p=0.02). Complicated pneumothoraces and pneumothoraces after upper lobe treatment were significantly lower in MMC (p=0.02). Major clinical outcomes showed no significant differences between the two cohorts. CONCLUSIONS In conclusion, modifying post-operative medical care to include bed rest for 48 hours after ELVR and cough suppression, if needed, might reduce the incidence of pneumothoraces. Prospective randomized studies with larger numbers of well-matched patients are needed to confirm the data.

Monteggia lesion in an Asian small-clawed otter (Aonyx cinerea).

A 10-yr-old female Asian small-clawed otter (Aonyx cinerea) presented with a history of right forelimb lameness. Antebrachial radiographs revealed a Monteggia lesion, classified by cranial radial head luxation and distal diaphyseal ulnar fracture. Open reduction with placement of an ulnar-radial positional screw was performed. The lateral collateral ligament was reconstructed using suture anchored by a condylar screw and bone tunnel in the radius. Reduction and proper implant placement was confirmed on postoperative radiographs. The ulnar-radial positional screw was removed 6 wk postoperatively to allow proper supination and pronation. Limb function was greatly improved at this time; however, a mild lameness was still observed. At 7 mo postoperatively, the otter was ambulating lameness-free. Radiographs documented proper joint reduction and stable condylar screw. At 32 mo postoperatively, the otter continued to exhibit normal ambulation.

Tumor-induced inflammation alters neutrophil phenotype and disease progression

Neutrophils are essential to combat infectious agents but contribute to collateral inflammatory damage. Likewise, neutrophils can kill cancer cells and have been shown to promote malignant growth and metastasis through immunosuppressive functions. Two articles in a recent issue of Nature reveal new mechanisms by which tumors induce changes in neutrophil phenotype through production of inflammatory cytokines. Although the two studies report different outcomes on the effects of neutrophils on tumor growth and metastasis, they delineate novel molecular pathways influencing neutrophil phenotype that may provide new approaches to harnessing neutrophil functions in the treatment of cancer.

Procedimientos de los investigadores de humanidades y ciencias sociales en la búsqueda de información

La búsqueda de información y sus problemas colaterales inciden en el desarrollo de la actividad de los investigadores. Nos proponemos analizar esta temática a través del estudio de las pautas de comportamiento de investigadores de la Facultad de Humanidades y Ciencias de la Educación de la Universidad de La Plata, para identificar conductas informativas y al mismo tiempo detectar obstáculos que impiden el aprovechamiento óptimo de la Biblioteca Central y las Bibliotecas Departamentales de la Institución. Los resultados obtenidos servirán de base para definir indicadores de calidad aplicables a la mejora continua de los servicios de biblioteca. Como resultado del análisis de metodologías aplicadas en estudios de usuarios se determinó combinar las perspectivas cuantitativa y cualitativa en este trabajo en curso

Procedimientos de los investigadores de humanidades y ciencias sociales en la búsqueda de información

La búsqueda de información y sus problemas colaterales inciden en el desarrollo de la actividad de los investigadores. Nos proponemos analizar esta temática a través del estudio de las pautas de comportamiento de investigadores de la Facultad de Humanidades y Ciencias de la Educación de la Universidad de La Plata, para identificar conductas informativas y al mismo tiempo detectar obstáculos que impiden el aprovechamiento óptimo de la Biblioteca Central y las Bibliotecas Departamentales de la Institución. Los resultados obtenidos servirán de base para definir indicadores de calidad aplicables a la mejora continua de los servicios de biblioteca. Como resultado del análisis de metodologías aplicadas en estudios de usuarios se determinó combinar las perspectivas cuantitativa y cualitativa en este trabajo en curso

Epiphytic orchid diversity found on trees and shrubs in coffee cultivated Afromontane rainforest, SW Ethiopia

The moist evergreen Afromontane forest of SW Ethiopia has become extremely fragmented and most remnants are intensively managed for cultivation of coffee (Coffea arabica). We investigated the distributions of epiphytic orchids in shade trees and their understory in forests with contrasting management intensity to determine biodiversity losses associated with coffee cultivation and to determine the capacity of coffee shrubs to act as refugia for orchid species. We studied epiphytic orchids in managed forests and natural forests and recorded orchid diversity and abundance in different tree zones of 339 trees and in the understory. Coffee management was associated with a downward shift of orchid species as orchid species were occurring in significantly lower tree zones in managed forest. The number of shrubs in the understory of managed forest was not higher than in natural forests, yet orchid abundance was higher in the understory of managed forests. Local extinctions of epiphytic orchids and species losses in the outer tree zones (a contraction of habitat) in managed forests are most likely driven by losses of large, complex-structured climax trees, and changes in microclimate, respectively. Coffee shrubs and their shade trees in managed forests are shown here to be a suitable habitat for only a limited set of orchid species. As farmers continue to convert natural forest into managed forest for coffee cultivation, further losses of habitat quality and collateral declines in regional epiphytic orchid diversity can be expected. Therefore, the conservation of epiphytic orchid diversity, as well as other components of diversity of the coffee forests, must primarily rely on avoiding coffee management intensification in the remaining natural forest. Convincing farmers to keep forest-climax trees in their coffee forest and to tolerate orchids on their coffee shrubs may also contribute to a more favorable conservation status of orchids in Ethiopian coffee agroecosystems.

Bank Borrowing and Financing of Medium-sized Firms in Indonesia

The improvement of financial intermediation functions is crucial for a robust banking system. When lending, banks have to cope with such problems as information asymmetry and adverse selection. In order to mitigate these problems, banks have to product information and improve their techniques of lending. During the 1998 financial crisis, Indonesia's banking system suffered severe damage and revealed that the country's banking intermediation functions did not work well. This paper examines the financial intermediation functions of banks in Indonesia and analyzes the importance of bank lending to firms. The focus is on medium-sized firms, and "relationship lending", one of the bank lending techniques, is used to examine financial intermediation in Indonesia. The results of logit regressions show that the relationship between a bank and a firm affects the probability of bank lending. The amount of borrowing and collateral are also affected by a firm's relationship with a bank. When viewed from the standpoint of relationship lending to medium-sized firms, Indonesian banks cannot be criticized for any malfunction of financial intermediation.

The effects of cocaine self-administration on dendritic spine density in the rat hippocampus are dependent on genetic background

Chronic exposure to cocaine induces modifications to neurons in the brain regions involved in addiction. Hence, we evaluated cocaine-induced changes in the hippocampal CA1 field in Fischer 344 (F344) and Lewis (LEW) rats, 2 strains that have been widely used to study genetic predisposition to drug addiction, by combining intracellular Lucifer yellow injection with confocal microscopy reconstruction of labeled neurons. Specifically, we examined the effects of cocaine self-administration on the structure, size, and branching complexity of the apical dendrites of CA1 pyramidal neurons. In addition, we quantified spine density in the collaterals of the apical dendritic arbors of these neurons. We found differences between these strains in several morphological parameters. For example, CA1 apical dendrites were more branched and complex in LEW than in F344 rats, while the spine density in the collateral dendrites of the apical dendritic arbors was greater in F344 rats. Interestingly, cocaine self-administration in LEW rats augmented the spine density, an effect that was not observed in the F344 strain. These results reveal significant structural differences in CA1 pyramidal cells between these strains and indicate that cocaine self-administration has a distinct effect on neuron morphology in the hippocampus of rats with different genetic backgrounds.

Evaluación de los co-beneficios sobre el desarrollo sostenible y la reducción de la pobreza de proyectos de mitigación del cambio climático en Brasil

El cambio climático y los diferentes aspectos del concepto de “desarrollo” están intrínsecamente interconectados. Por un lado, el desarrollo económico de nuestras sociedades ha contribuido a un aumento insostenible de las emisiones de gases de efecto invernadero, las cuales están desestabilizando el sistema climático global, generando al mismo tiempo una distribución desigual de la capacidad de las personas para hacer frente a estos cambios. Por otro lado, en la actualidad existe un amplio consenso sobre que el cambio climático impacta directamente y de manera negativa sobre el denominando desarrollo sostenible. De igual manera, cada vez existe un mayor consenso de que el cambio climático va a desafiar sustancialmente nuestra capacidad de erradicar la pobreza a medio y largo plazo. Ante esta realidad, no cabe duda de que las estrategias de adaptación son esenciales para mantener el desarrollo. Es por esto que hasta el momento, los mayores esfuerzos realizados por unir las agendas globales de la lucha contra la pobreza y del cambio climático se han dado en el entorno de la adaptación al cambio climático. Sin embargo, cada vez son más los actores que defienden, desde distintos escenarios, que existen sinergias entre la mitigación de emisiones y la mejora de las condiciones de vida de las poblaciones más vulnerables, favoreciendo así un “desarrollo sostenible” sin disminuir los recursos financieros destinados a la adaptación. Para hacer efectivo este potencial, es imprescindible identificar diseños de estrategias de mitigación que incrementen los resultados de desarrollo, contribuyendo al desarrollo sostenible al mismo tiempo que a reducir la pobreza. En este contexto se sitúa el objetivo principal de esta investigación, consistente en analizar los co-beneficios locales, para el desarrollo sostenible y la reducción la pobreza, de proyectos de mitigación del cambio climático que se implementan en Brasil. Por co-beneficios se entienden, en el lenguaje de las discusiones internacionales de cambio climático, aquellos beneficios que van más allá de la reducción de emisiones de Gases de Efecto Invernadero (GEI) intrínsecas por definición a los proyectos de mitigación. Los proyectos de mitigación más relevantes hasta el momento bajo el paraguas de la Convención Marco de las Naciones Unidas para el Cambio Climático (CMNUCC), son los denominados Mecanismos de Desarrollo Limpio (MDL) del Protocolo de Kioto. Sin embargo, existen alternativas de proyectos de mitigación (tales como los denominados “estándares adicionales” a los MDL de los Mercados Voluntarios de Carbono y las Tecnologías Sociales), que también serán tenidos en cuenta en el marco de este estudio. La elección del tema se justifica por la relevancia del mismo en un momento histórico en el que se está decidiendo el futuro del régimen climático a partir del año 2020. Aunque en el momento de redactar este documento, todavía no se ha acordado la forma que tendrán los futuros instrumentos de mitigación, sí que se sabe que los co-beneficios de estos instrumentos serán tan importantes, o incluso más, que las reducciones de GEI que generan. Esto se debe, principalmente, a las presiones realizadas en las negociaciones climáticas por parte de los países menos desarrollados, para los cuales el mayor incentivo de formar parte de dichas negociaciones se basa principalmente en estos potenciales co-beneficios. Los resultados de la tesis se estructuran alrededor de tres preguntas de investigación: ¿cómo están contribuyendo los MDL implementados en Brasil a generar co-beneficios que fomenten el desarrollo sostenible y reduzcan la pobreza?; ¿existen proyectos de mitigación en Brasil que por tener compromisos más exigentes en cuanto a su contribución al desarrollo sostenible y/o la reducción de la pobreza que los MDL estén siendo más eficientes que estos en relación a los co-beneficios que generan?; y ¿qué características de los proyectos de mitigación pueden resultar críticas para potenciar sus co-beneficios en las comunidades en las que se implementan? Para dar respuesta a estas preguntas, se ha desarrollado durante cuatro años una labor de investigación estructurada en varias fases y en la que se combinan diversas metodologías, que abarcan desde el desarrollo de un modelo de análisis de cobeneficios, hasta la aplicación del mismo tanto a nivel documental sobre 194 documentos de diseño de proyecto (denominado análisis ex-ante), como a través de 20 casos de estudio (denominado análisis ex-post). Con la realización de esta investigación, se ha confirmado que los requisitos existentes hasta el momento para registrar un proyecto como MDL bajo la CMNUCC no favorecen sustancialmente la generación de co-beneficios locales para las comunidades en las que se implementan. Adicionalmente, se han identificado prácticas y factores, que vinculadas a las actividades intrínsecas de los proyectos de mitigación, son efectivas para incrementar sus co-beneficios. Estas prácticas y factores podrán ser tenidas en cuenta tanto para mejorar los requisitos de los actuales proyectos MDL, como para apoyar la definición de los nuevos instrumentos climáticos. ABSTRACT Climate change and development are inextricably linked. On the one hand, the economic development of our societies has contributed to the unsustainable increase of Green House Gases emissions, which are destabilizing the global climate system while fostering an unequal distribution of people´s ability to cope with these changes. On the other hand, there is now a consensus that climate change directly impacts the so-called sustainable development. Likely, there is a growing agreement that climate change will substantially threaten our capacity to eradicate poverty in the medium and long term. Given this reality, there is no doubt that adaptation strategies are essentials to keep development. This is why, to date, much of the focus on poverty in the context of climate change has been on adaptation However, without diverting resources from adaptation, there may exist the potential to synergize efforts to mitigate emissions, contribute to sustainable development and reduce poverty. To fulfil this potential, it is key identifying how mitigation strategies can also support sustainable development and reduce poverty. In this context, the main purpose of this investigation is to explore the co-benefits, for sustainable development and for poverty reduction, of climate change mitigation projects being implemented in Brazil. In recent years the term co-benefits, has been used by policy makers and academics to refer the potentially large and diverse range of collateral benefits that can be associated with climate change mitigation policies in addition to the direct avoided climate impact benefits. The most relevant mitigation projects developed during the last years under the United Nations Framework Convention on Climate Change (UNFCCC) are the so-called Clean Development Mechanisms (CDM) of the Kyoto Protocol. Thus, this research will analyse this official mechanism. However, there are alternatives to the mitigation projects (such as the "add-on standards" of the Voluntary Carbon Markets, and the Social Technologies) that will also be assessed as part of the research. The selection of this research theme is justified because its relevance in a historic moment in which proposals for a future climate regime after 2020 are being negotiated. Although at the moment of writing this document, there is not a common understanding on the shape of the new mitigation instruments, there is a great agreement about the importance of the co-benefits of such instruments, which may be even more important for the Least Developed Countries that their expected greenhouse gases emissions reductions. The results of the thesis are structured around three research questions: how are the CDM projects being implemented in Brazil generating local co-benefits that foster sustainable development and poverty reduction?; are other mitigation projects in Brazil that due to their more stringent sustainable development and/o poverty reduction criteria, any more successful at delivering co-benefits than regular CDM projects?; and what are the distinguishing characteristics of mitigation projects that are successful at delivering co-benefits? To answer these research questions, during four years it has been developed a research work structured in several phases and combining various methodologies. Those methodologies cover from the development of a co-benefits assessment model, to the application of such model both to a desktop analysis of 194 project design documents, and to 20 case studies using field data based on site visits to the project sites. With the completion of this research, it has been confirmed that current requirements to register a CDM project under the UNFCCC not substantially favour co-benefits at the local level. In addition, some practices and factors enablers of co-benefits have been identified. These characteristics may be taken into consideration to improve the current CDM and to support the definition of the new international market mechanisms for climate mitigation.

Combine use of Selected Schizosaccharomyces pombe and Lachancea thermotolerans Yeast Strains as an Alternative to the Traditional Malolactic Fermentation in Red Wine Production

Most red wines commercialized in the market use the malolactic fermentationprocess in order to ensure stability from a microbiological point of view. In this secondfermentation, malic acid is converted into L-lactic acid under controlled setups. Howeverthis process is not free from possible collateral effects that on some occasions produceoff-flavors, wine quality loss and human health problems. In warm viticulture regions suchas the south of Spain, the risk of suffering a deviation during the malolactic fermentationprocess increases due to the high must pH. This contributes to produce wines with highvolatile acidity and biogenic amine values. This manuscript develops a new red winemakingmethodology that consists of combining the use of two non-Saccharomyces yeast strains asan alternative to the traditional malolactic fermentation. In this method, malic acid is totallyconsumed by Schizosaccharomyces pombe, thus achieving the microbiological stabilizationobjective, while Lachancea thermotolerans produces lactic acid in order not to reduce andeven increase the acidity of wines produced from low acidity musts. This technique reducesthe risks inherent to the malolactic fermentation process when performed in warm regions.The result is more fruity wines that contain less acetic acid and biogenic amines than thetraditional controls that have undergone the classical malolactic fermentation.

A methodology proposal to obtain operational parameter forecasts and operational risk assessment in container terminals

Las terminales de contenedores son sistemas complejos en los que un elevado número de actores económicos interactúan para ofrecer servicios de alta calidad bajo una estricta planificación y objetivos económicos. Las conocidas como "terminales de nueva generación" están diseñadas para prestar servicio a los mega-buques, que requieren tasas de productividad que alcanzan los 300 movimientos/ hora. Estas terminales han de satisfacer altos estándares dado que la competitividad entre terminales es elevada. Asegurar la fiabilidad de las planificaciones del atraque es clave para atraer clientes, así como reducir al mínimo el tiempo que el buque permanece en el puerto. La planificación de las operaciones es más compleja que antaño, y las tolerancias para posibles errores, menores. En este contexto, las interrupciones operativas deben reducirse al mínimo. Las principales causas de dichas perturbaciones operacionales, y por lo tanto de incertidumbre, se identifican y caracterizan en esta investigación. Existen una serie de factores que al interactuar con la infraestructura y/o las operaciones desencadenan modos de fallo o parada operativa. Los primeros pueden derivar no solo en retrasos en el servicio sino que además puede tener efectos colaterales sobre la reputación de la terminal, o incluso gasto de tiempo de gestión, todo lo cual supone un impacto para la terminal. En el futuro inmediato, la monitorización de las variables operativas presenta gran potencial de cara a mejorar cualitativamente la gestión de las operaciones y los modelos de planificación de las terminales, cuyo nivel de automatización va en aumento. La combinación del criterio experto con instrumentos que proporcionen datos a corto y largo plazo es fundamental para el desarrollo de herramientas que ayuden en la toma de decisiones, ya que de este modo estarán adaptadas a las auténticas condiciones climáticas y operativas que existen en cada emplazamiento. Para el corto plazo se propone una metodología con la que obtener predicciones de parámetros operativos en terminales de contenedores. Adicionalmente se ha desarrollado un caso de estudio en el que se aplica el modelo propuesto para obtener predicciones de la productividad del buque. Este trabajo se ha basado íntegramente en datos proporcionados por una terminal semi-automatizada española. Por otro lado, se analiza cómo gestionar, evaluar y mitigar el efecto de las interrupciones operativas a largo plazo a través de la evaluación del riesgo, una forma interesante de evaluar el effecto que eventos inciertos pero probables pueden generar sobre la productividad a largo plazo de la terminal. Además se propone una definición de riesgo operativo junto con una discusión de los términos que representan con mayor fidelidad la naturaleza de las actividades y finalmente, se proporcionan directrices para gestionar los resultados obtenidos. Container terminals are complex systems where a large number of factors and stakeholders interact to provide high-quality services under rigid planning schedules and economic objectives. The socalled next generation terminals are conceived to serve the new mega-vessels, which are demanding productivity rates up to 300 moves/hour. These terminals need to satisfy high standards because competition among terminals is fierce. Ensuring reliability in berth scheduling is key to attract clients, as well as to reduce at a minimum the time that vessels stay the port. Because of the aforementioned, operations planning is becoming more complex, and the tolerances for errors are smaller. In this context, operational disturbances must be reduced at a minimum. The main sources of operational disruptions and thus, of uncertainty, are identified and characterized in this study. External drivers interact with the infrastructure and/or the activities resulting in failure or stoppage modes. The later may derive not only in operational delays but in collateral and reputation damage or loss of time (especially management times), all what implies an impact for the terminal. In the near future, the monitoring of operational variables has great potential to make a qualitative improvement in the operations management and planning models of terminals that use increasing levels of automation. The combination of expert criteria with instruments that provide short- and long-run data is fundamental for the development of tools to guide decision-making, since they will be adapted to the real climatic and operational conditions that exist on site. For the short-term a method to obtain operational parameter forecasts in container terminals. To this end, a case study is presented, in which forecasts of vessel performance are obtained. This research has been entirely been based on data gathered from a semi-automated container terminal from Spain. In the other hand it is analyzed how to manage, evaluate and mitigate disruptions in the long-term by means of the risk assessment, an interesting approach to evaluate the effect of uncertain but likely events on the long-term throughput of the terminal. In addition, a definition for operational risk evaluation in port facilities is proposed along with a discussion of the terms that better represent the nature of the activities involved and finally, guidelines to manage the results obtained are provided.

Calibration of accelerometers for the measurement of microvibrations

The accelerometers used for the measurement of microvibrations or microgravity applications, such as active control of space structures, attitude control, scientific payloads, or even on-Earth testing of structures at very low-excitation levels, require a dedicated calibration procedure that includes the gravitational effects. Otherwise, on-Earth calibrations can be inaccurate due to the collateral projection of the local gravity onto the sensitive axis. An on-Earth calibration technique for the 107102s amplitude range and 0-100-Hz frequency range is described. Special attention has been given to the modeling of gravitational effects on the response of the calibration device and the accelerometer itself. The sensitivity and resolution tests performed on piezoelectric accelerometers showthe accuracy andthe potential of thistechnique. Typical scale factorun certainty, which hasbeen carefully analyzed, is of the order of 2% at acceleration levels of 10sg.