21 resultados para field work

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Afdeyu Station is one of the few river gauging stations in the highlands of Eritrea where daily measurements are taken. As a result of damages, the station was refurbished, and the cross section of the gauge was changed to have better control of minimal runoff. The gauge therefore had to be re-calibrated. This publication documents this process and also provides the new calibration curve, based on extensive field work carried out in the rainy season 2009

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The reconstruction of past environmental and historical events is much needed in Amazonia, a region at the centre of heated debates about the extent of pre-Columbian human disturbance of the natural ecosystems. Important aspects of this debate are to establish to what extent the rise of social complexity was influenced by the local geo-ecology; and what productive strategies were adopted in order to sustain these societies. The Llanos de Moxos (LM), in the Bolivian Amazon, is a vast floodplain made up of a variety of geo-ecological sub regions that host many different types of pre-Columbian earthworks. Therefore, it offers an excellent opportunity to compare different kinds of archaeological landscapes and their relationship to different pre-Columbian cultures and environmental settings. This paper analyses the links between pre-Columbian earthworks and the local geo-ecology in two regions of the LM: 1) the platform field region (PFR) in the north of Santa Ana de Yacuma, where the highest concentration of raised fields has been documented, and 2) the monumental mounds region (MMR) south and east of Trinidad, where >100 pre-Columbian monumental mounds are found. The study draws from remote sensing and GIS analysis, field work in the Bolivian lowlands, and laboratory analysis. Differences in the way people transformed the landscape in the PFR and MMR seem to respond to differences in the local geo-ecology of the two sites. The results also suggest that environmental conditions exerted an important, though not exclusive, control over the levels of social complexity that were reached in different areas of the LM.

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INTRODUCTION Out-migration from mountain areas is leaving behind half families and elderly to deal with managing the land alongside daily life challenges. A potential reduction of labour force as well as expertise on cropping practices, maintenance of terraces and irrigation canals, slope stabilization, grazing, forest and other land management practices are further challenged by changing climate conditions and increased environmental threats. An understanding of the resilience of managed land resources in order to enhance adaptation to environmental and socio-economic variability, and evidence of the impact of Sustainable Land Management (SLM) on the mitigation of environmental threats have so far not sufficiently been tackled. The study presented here aims to find out how land management in mountains is being affected by migration in the context of natural hazards and climate change in two study sites, namely Quillacollo District of Bolivia and Panchase area of Western Nepal, and which measures are needed to increase resilience of livelihoods and land management practices. The presentation includes draft results from first field work periods in both sites. A context of high vulnerability According to UNISDR, vulnerability is defined as “the characteristics and circumstances of a community, system or asset that make it susceptible to the damaging effects of a hazard”.Hazards are another threat affecting people’s livelihood in mountainous area. They can be either natural or human induced. Landslides, debris flow and flood are affecting peopleGood land management can significantly reduce occurrence of hazards. In the opposite bad land management or land abandonment can lead to negative consequences on the land, and thus again increase vulnerability of people’s livelihoods. METHODS The study integrates bio-physical and socio-economic data through a case study as well as a mapping approach. From the social sciences, well-tested participatory qualitative methodologies, typically used in Vulnerability and Capacity Analyses, such as semi-structured interviews with so-called ‘key informants’, transect walks, participatory risk and social resource mapping are applied. The bio-physical analysis of the current environmental conditions determining hazards and structural vulnerability are obtained from remote sensing analysis, field work studies, and GIS analysis The assessment of the consequences of migration in the area of origin is linked with a mapping and appraisal of land management practices (www.wocat.net, Schwilch et al., 2011). The WOCAT mapping tool (WOCAT/LADA/DESIRE 2008) allows capturing the major land management practices / technologies, their spread, effectiveness and impact within a selected area. Data drawn from a variety of sources are compiled and harmonised by a team of experts, consisting of land degradation and conservation specialists working in consultation with land users from various backgrounds. The specialists’ and land users’ knowledge is combined with existing datasets and documents (maps, GIS layers, high-resolution satellite images, etc.) in workshops that are designed to build consensus regarding the variables used to assess land degradation and SLM. This process is also referred to as participatory expert assessment or consensus mapping. The WOCAT mapping and SLM documentation methodologies are used together with participatory mapping and other socio-economic data collection (interviews, questionnaires, focus group discussions, expert consultation) to combine information about migration types and land management issues. GIS and other spatial visualization tools (e.g. Google maps) will help to represent and understand these links. FIRST RESULTS Nepal In Nepal, migration is a common strategy to improve the livelihoods. Migrants are mostly men and they migrate to other Asian countries, first to India and then to the Gulf countries. Only a few women are migrating abroad. Women migrate essentially to main Nepali cities when they can afford it. Remittances are used primarily for food and education; however they are hardly used for agricultural purposes. Besides traditional agriculture being maintained, only few new practices are emerging, such as vegetable farming or agroforestry. The land abandonment is a growing consequence of outmigration, resulting in the spreading of invasive species. However, most impacts of migration on land management are not yet clear. Moreover, education is a major concern for the respondents; they want their children having a better education and get better opportunities. Linked to this, unemployment is another major concern of the respondents, which in turn is “solved” through outmigration. Bolivia Migration is a common livelihood strategy in Bolivia. In the area of study, whole families are migrating downward to the cities of the valleys or to other departments of Bolivia, especially to Chapare (tropics) for the coca production and to Santa Cruz. Some young people are migrating abroad, mostly to Argentina. There are few remittances and if those are sent to the families in the mountain areas, then they are mainly used for agriculture purpose. The impacts of migration on land management practices are not clear although there are some important aspects to be underlined. The people who move downward are still using their land and coming back during part of the week to work on it. As a consequence of this multi-residency, there is a tendency to reduce land management work or to change the way the land is used. As in Nepal, education is a very important issue in this area. There is no secondary school, and only one community has a primary school. After the 6th grade students have therefore to go down into the valley towns to study. The lack of basic education is pushing more and more people to move down and to leave the mountains. CONCLUSIONS This study is on-going, more data have to be collected to clearly assess the impacts of out-migration on land management in mountain areas. The first results of the study allow us to present a few interesting findings. The two case studies are very different, however in both areas, young people are not staying anymore in the mountains and leave behind half families and elderly to manage the land. Additionally in both cases education is a major reason for moving out, even though the causes are not always the same. More specifically, in the case of Nepal, the use of remittances underlines the fact that investment in agriculture is not the first choice of a family. In the case of Bolivia, some interesting findings showed that people continue to work on their lands even if they move downward. The further steps of the study will help to explore these interesting issues in more detail. REFERENCES Schwilch G., Bestelmeyer B., Bunning S., Critchley W., Herrick J., Kellner K., Liniger H.P., Nachtergaele F., Ritsema C.J., Schuster B., Tabo R., van Lynden G., Winslow M. 2011. Experiences in Monitoring and Assessment of Sustainable Land Management. Land Degradation & Development 22 (2), 214-225. Doi 10.1002/ldr.1040 WOCAT/LADA/DESIRE 2008. A Questionnaire for Mapping Land Degradation and Sustainable Land Management. Liniger H.P., van Lynden G., Nachtergaele F., Schwilch G. (eds), Centre for Development and Environment, Institute of Geography, University of Berne, Berne

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Our study considers the natural resources of the Miombo forests in Cabo Delgado from a broad ecosystems perspective. Thus, our view goes beyond the disciplinary approaches of forestry, agronomy, biology or zoology, and also of the social sciences, namely anthropology, history, sociology, political science or economics. The present study aims to establish a dialogue and create synergies between Miti Ltd. – the logging company and owner of the forest concessions – as well as government and state structures at the various levels and the communities – through the Committees on Natural Resources – in order to promote the sustainable use of resources and ecosystems. The research methodology we used can broadly be described as moderated transdisciplinary interaction for action-research based on the approach known as Learning for Sustainability (LforS, http://www.cde.unibe.ch/Pages/Project/2/14/Learning-for-Sustainability-Extension-Approach.aspx). The research methods used include: LforS seminars; field work; forests observations focusing, among others, on ecosystems, trees, wildlife, and burned areas; visits to farms; and interviews. We conducted both collective interviews and individual interviews, including with key informants. The main results indicate that members of the Committee on Natural Resources have a dual attitude: their statements defend the paradigm of sustainable use of natural resources as well as their own immediate monetary gain. They are willing to apply the values, concepts and theories of sustainable development that underpin the establishment of Committees on Natural Resources if they are paid for their work or if they can derive direct benefits from it, i.e. if they can earn a salary or allowance. If this does not happen, however, they are willing to allow actors to engage in illegal hunting or logging activities. This dual attitude also exists in relation to forestry operators. If the concession workers pay the committee members in cash or provide goods, they can run their business even if they violate the law. Natural forest regeneration in Nkonga and Namiune already shows the impact of such use. Although there are many saplings that could basically ensure continuous regeneration under sustainable management, repeated burning is damaging the young trees, deforming them and killing a great number of them. Campaigns against uncontrolled fires are ineffective because the administrative and political authorities have a dual attitude as well and are also part of the group that uses resources to their own profit and benefit. There are institutional structures within the administration, populations, and communities to perform regulating functions, create and implement rules, punish offenders, and oversee resource use. However, they feel that since they are not paid for performing these functions, they do not have to do so. This attitude shows a lack of awareness, but also indicates a situation where everyone seeks to derive maximum benefits from existing resource use patterns. Anything goes.

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The challenges of research ethics and methodologies have been reflected on extensively, but – aside from the context of feminist methodologies – less so in relation to research on particular migration sites such as in transit, detention centres, at the borders or within migration administration. First attempts in this direction have been made (Düvell et al. 2010, Fresia et al. 2005, Riedner 2014, van Liempt/Bilger2009), however, more reflection and theorization is needed, considering the contested nature of these temporal and volatile sites. In this workshop, we thus aim at examining methodological as well as ethical questions that arise during field work: We attempt to reflect the power relations involved in the research process, the ethics of research design, the dissemination of research results, the question of gaining access to and – whenever necessary – staying in contact with our research subjects. How can we negotiate informed consent with subjects whose life is currently marked by transit and insecurity concerning their own future, and who are in an uncertain situation in which substantial information (legal, social, cultural etc.) is likely to be missing? How do we deal with the dilemma of possibly contributing to knowledge production that might facilitate removals and deportations in the future, considering that the reception of the results is not in the hands of the researchers? How do we deal with the anticipated as well as unexpected impacts of our research on social and political practice? Regarding fieldwork in state institutions, how do we negotiate the multiple loyalties we often find ourselves faced with as social researchers, both with the excluded migrants and with the authorities implementing the exclusions – two groupings considered to be opposite to each other (Lavanchy 2013)? Which different roles do researchers need to take on? The aim of our workshop is first and foremost to exchange experiences on fieldwork with others doing qualitative research on related topics and to consider its possible implications – including affective dimensions – for all participants involved in the research process: the migrants, the security staff of detention centres, its social workers, border police and bureaucrats and, last but not least, the researchers themselves. Furthermore, we generally wish to reflect upon the question of how best to conduct research in this contested field, applying an interdisciplinary perspective.

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Social desirability and the fear of negative consequences often deter a considerable share of survey respondents from responding truthfully to sensitive questions. Thus, resulting prevalence estimates are biased. Indirect techniques for surveying sensitive questions such as the Randomized Response Technique are intended to mitigate misreporting by providing complete concealment of individual answers. However, it is far from clear whether these indirect techniques actually produce more valid measurements than standard direct questioning. In order to evaluate the validity of different sensitive question techniques we carried out an online validation experiment at Amazon Mechanical Turk in which respondents' self-reports of norm-breaking behavior (cheating in dice games) were validated against observed behavior. This document describes the design of the validation experiment and provides details on the questionnaire, the different sensitive question technique implementations, the field work, and the resulting dataset. The appendix contains a codebook of the data and facsimiles of the questionnaire pages and other survey materials.

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Based on extensive field work and years of personal experience, the authors discuss the development of tourism in the Great Himalaya of Nepal from the early days of mountaineering to present-day trekking. Tourism and its potentials, drawbacks, and risks are illustrated with a focus on the Khumbu/Everest and Annapurna regions, the most popular mountain destinations in the country. The themes addressed include: growth and expansion of mountain tourism; employment and income generation; wealth, poverty, and livelihood as reflected in statistics and personal accounts by local people; the revival of trade with Tibet; tourism and the role of women; the crucial role played by institutions, policies and political stability; and environmental issues such as forest degradation, garbage management, and trail damage. With its numerous illustrations, text boxes and quotes, the book is intended for a broad readership of policy- and decision-makers in tourism and development, scholars, and tourists and mountaineers who take an interest in mountain development in the Great Himalaya and elsewhere.

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Body height decreases throughout the day due to fluid loss from the intervertebral disk. This study investigated whether spinal shrinkage was greater during workdays compared with nonwork days, whether daily work stressors were positively related to spinal shrinkage, and whether job control was negatively related to spinal shrinkage. In a consecutive 2-week ambulatory field study, including 39 office employees and 512 days of observation, spinal shrinkage was measured by a stadiometer, and calculated as body height in the morning minus body height in the evening. Physical activity was monitored throughout the 14 days by accelerometry. Daily work stressors, daily job control, biomechanical workload, and recreational activities after work were measured with daily surveys. Multilevel regression analyses showed that spinal disks shrank more during workdays than during nonwork days. After adjustment for sex, age, body weight, smoking status, biomechanical work strain, and time spent on physical and low-effort activities during the day, lower levels of daily job control significantly predicted increased spinal shrinkage. Findings add to knowledge on how work redesign that increases job control may possibly contribute to preserving intervertebral disk function and preventing occupational back pain.

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OBJECTIVES: To analyse the results of recent studies not yet included in a 2003 report of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) on occupational exposure to low-frequency electromagnetic fields as potential risk factor for neurodegenerative diseases. METHODS: A literature search was conducted in the online databases of PubMed, ISI Web of Knowledge, DIMDI and COCHRANE, as well as in specialised databases and journals. Eight studies published between January 2000 and July 2005 were included in the review. RESULTS: The findings of these studies contribute to the evidence of an association between occupational magnetic field exposure and the risk of dementia. Regarding amyotrophic lateral sclerosis, the recent results confirm earlier observations of an association with electric and electronic work and welding. Its relationship with magnetic field exposure remains unsolved. There are only few findings pointing towards an association between magnetic field exposure and Parkinson's disease. CONCLUSIONS: The epidemiological evidence for an association between occupational exposure to low-frequency electromagnetic fields and the risk of dementia has increased during the last five years. The impact of potential confounders should be evaluated in further studies.

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A pi-conjugated tetrathiafulvalene-fused perylenediimide (TTF-PDI) molecular dyad is successfully used as a solution-processed active material for light sensitive ambipolar field-effect transistors with balanced hole and electron mobilities. The photo-response of the TTF-PDI dyad resembles its absorption profile. Wavelength-dependent photoconductivity measurements reveal an important photo-response at an energy corresponding to a PDI-localized electronic pi-pi* transition and also a more moderate effect due to an intramolecular charge transfer from the HOMO localized on the TTF unit to the LUMO localized on the PDI moiety. This work clearly elucidates the interplay between intra- and intermolecular electronic processes in organic devices.

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Since approximately two thirds of epileptic patients are non-eligible for surgery, local axonal fiber transections might be of particular interest for them. Micrometer to millimeter wide synchrotron-generated X-ray beamlets produced by spatial fractionation of the main beam could generate such fiber disruptions non-invasively. The aim of this work was to optimize irradiation parameters for the induction of fiber transections in the rat brain white matter by exposure to such beamlets. For this purpose, we irradiated cortex and external capsule of normal rats in the antero-posterior direction with a 4 mm×4 mm array of 25 to 1000 µm wide beamlets and entrance doses of 150 Gy to 500 Gy. Axonal fiber responses were assessed with diffusion tensor imaging and fiber tractography; myelin fibers were examined histopathologically. Our study suggests that high radiation doses (500 Gy) are required to interrupt axons and myelin sheaths. However, a radiation dose of 500 Gy delivered by wide minibeams (1000 µm) induced macroscopic brain damage, depicted by a massive loss of matter in fiber tractography maps. With the same radiation dose, the damage induced by thinner microbeams (50 to 100 µm) was limited to their paths. No macroscopic necrosis was observed in the irradiated target while overt transections of myelin were detected histopathologically. Diffusivity values were found to be significantly reduced. A radiation dose ≤ 500 Gy associated with a beamlet size of < 50 µm did not cause visible transections, neither on diffusion maps nor on sections stained for myelin. We conclude that a peak dose of 500 Gy combined with a microbeam width of 100 µm optimally induced axonal transections in the white matter of the brain.

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OBJECTIVE The aim of this work is to investigate and compare cardiac proton density (PD) weighted fast field echo (FFE) post-mortem magnetic resonance (PMMR) imaging with standard cardiac PMMR imaging (T1-weighted and T2-weighted turbo spin-echo (TSE)), postmortem CT (PMCT) as well as autopsy. MATERIALS AND METHODS Two human cadavers sequentially underwent cardiac PMCT and PMMR imaging (PD-weighted FFE, T1-weighted and T2-weighted TSE) and autopsy. The cardiac PMMR images were compared to each other as well as to PMCT and autopsy findings. RESULTS For the first case, cardiac PMMR exhibited a focal region of low signal in PD-weighted FFE and T2-weighted TSE images, surrounded by a signal intense rim in the T2-weighted images. T1-weighted TSE and PMCT did not appear to identify any focal abnormality. Macroscopic inspection identified a blood clot; histology confirmed this to be a thrombus with an adhering myocardial infarction. In the second case, a myocardial rupture with heart tamponade was identified in all PMMR images, located at the anterior wall of the left ventricle; PMCT excluded additional ruptures. In PD-weighted FFE and T2-weighted TSE images, it occurred hypo-intense, while resulting in small clustered hyper-intense spots in T1-weighted TSE. Autopsy confirmed the PMMR and PMCT findings. CONCLUSIONS Presented initial results have shown PD-weighted FFE to be a valuable imaging sequence in addition to traditional T2-weighted TSE imaging for blood clots and myocardial haemorrhage with clearer contrast between affected and healthy myocardium.

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The aim of this work was to clarify the mechanism taking place in field-enhanced sample injection coupled to sweeping and micellar EKC (FESI-Sweep-MEKC), with the utilization of two acidic high-conductivity buffers (HCBs), phosphoric acid or sodium phosphate buffer, in view of maximizing sensitivity enhancements. Using cationic model compounds in acidic media, a chemometric approach and simulations with SIMUL5 were implemented. Experimental design first enabled to identify the significant factors and their potential interactions. Simulation demonstrates the formation of moving boundaries during sample injection, which originate at the initial sample/HCB and HCB/buffer discontinuities and gradually change the compositions of HCB and BGE. With sodium phosphate buffer, the HCB conductivity increased during the injection, leading to a more efficient preconcentration by staking (about 1.6 times) than with phosphoric acid alone, for which conductivity decreased during injection. For the same injection time at constant voltage, however, a lower amount of analytes was injected with sodium phosphate buffer than with phosphoric acid. Consequently sensitivity enhancements were lower for the whole FESI-Sweep-MEKC process. This is why, in order to maximize sensitivity enhancements, it is proposed to work with sodium phosphate buffer as HCB and to use constant current during sample injection.

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Background There will be increasing competition for young physicians worldwide as more and more physicians retire. While enthusiasm towards GP work is important for GP teachers as role models, satisfaction within the profession has declined. This study aims to determine if medical students’ desire to become GPs is related to the job satisfaction of their teaching GPs and explore the factors tied to this job satisfaction. Methods In this cross-sectional, correlational study, teaching GPs of the University of Bern and the fourth year medical students completing internships with them filled in separate questionnaires. Results Whether or not the GP teacher is perceived by a student to be satisfied with her/his job is correlated to that student’s satisfaction with the internship, which in turn, is correlated with student’s wish to be a GP after the internship. Results show which factors are most related to GP job satisfaction and the effect of working hours and their composition. Conclusions Medical students’ perception of their GP teachers’ job satisfaction positively affect their wish to become GPs, and their satisfaction with their internships adds to this. Enhancing the positive aspects of GP work, such as recognition, and improving negative ones, such as administrative duties, are necessary to attract medical students into the GP field.

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Background. In the field of information technology (IT) time pressure is common. Working with tight deadlines together on the same task increases the risk of social stressors referring to tensions and conflicts at work. Purpose. This field study tested both the association of time pressure and social stressors with blood pressure during work. Method. Seven employees – staff of a small IT enterprise – participated in repeated ambulatory blood pressure measurements over the course of one week. Time pressure and social stressors at work were assessed by questionnaire at the beginning of the study. Results. Multilevel regression analyses of 138 samples revealed higher levels of time pressure to be related to marginally significant increases in mean arterial blood pressure at noon and in the afternoon. In addition, higher levels of social stressors at work were significantly associated to elevated mean arterial pressure in the afternoon. Conclusion. Findings support the view that threats to the social self play an important role in occupational health.