509 research outputs found
Analysis of vibration based windmill coupled micromachined energy harvester
The present work exploits the centripetal, Coriolis and Euler forces generated in a rotating windmill. The MEMS device is placed on the blade of a windmill to harvest the energy. Modal analysis is carried out to optimize the dimensions of the structure to match the desired conditions. The real time response of the structure and the voltage generated in the piezoelectric layer are evaluated using transient analysis. It was noticed that Euler and Coriolis forces have a significant contribution in the initial time when the wind turbine accelerates from rest. The later portion is dominated by the Coriolis and Euler forces, and in some instances they cancel out each other. However, there is always a steady contribution from the centripetal force which is proportional to the magnitude of angular velocity of the wind turbine
The Sheared Central Venous Catheter?
A fractured central venous catheter (CVC) with embolization of the distal fragment may lead to life-threatening complications. We had inserted a right subclavian CVC in a 68-year-old female which upon a follow-up chest X-ray appeared to have been sheared. A guidewire was inserted through the CVC until the J-tip was just beyond the tip of the CVC which were then withdrawn as a single assembly. We suspected that the tip of the guidewire might have been entrapped in the opening of the middle port, which upon withdrawal of the guidewire could have led to CVC folding upon itself and shearing
Global Forces of Change: Implications for Forest-poverty Dynamics
This article examines global trends likely to influence forests and tree-based systems and considers the poverty implications of these interactions. The trends, identified through a series of expert discussions and review of the literature, include: (i) climatic impacts mediated through changes in forests, (ii) growth in commodity markets, (iii) shifts in private and public forest sector financing, (iv) technological advances and rising interconnectivity, (v) global socio-political movements, and (vi) emerging infectious diseases. These trends bring opportunities and risks to the forest-reliant poor. A review of available evidence suggests that in a business-as-usual scenario, the cumulative risks posed by these global forces, in conjunction with limited rights, resources, and skills required to prosper from global changes, are likely to place poor and transient poor households under additional stress. The article concludes with an assessment of how interventions for enhancing forest management, combined with supportive policy and institutional conditions, can contribute to a different and more prosperous future for forests and people
What is the evidence for the contribution of forests to poverty alleviation? A systematic map protocol
This is the final version of the article. Available from BioMed Central via the DOI in this record.Background: Forests provide an essential resource that support the livelihoods of an estimated 20% of the global population. Forests are thought to serve in three primary roles to support livelihoods: subsistence, safety nets, and pathways to prosperity. While we have a working understanding of how poor people depend on forests in individual sites and countries, much of this evidence is dispersed and not easily accessible. Thus, while the importance of forest ecosystems and resources to contribute to poverty alleviation has been increasingly emphasized in international policies, conservation and development initiatives and investments- the strength of evidence to support how forests can affect poverty outcomes is still unclear. This study takes a systematic mapping approach to scope, identify and describe studies that measure the effect of forest-based activities on poverty outcomes at local and regional scales. This effort builds upon an existing systematic map on linkages between conservation and human well-being in order to make this process more efficient. We will conduct a refined and updated search strategy pertinent to forests-poverty linkages to glean additional evidence from studies outside the scope of the original map. Results of this study can be used for informing conservation and development policy and practices in global forest ecosystems and highlight evidence gaps where future primary studies and systematic reviews can add value. Methods: We build upon the search strategy outlined in McKinnon et al. (Environ Evid 1-25, 2016) and expand our search to cover a total of 7 bibliographic databases, 15 organizational websites, 8 existing systematic reviews and maps, and evidence gap maps, and solicit key informants. All searches will be conducted in English and encompass all nations. Search results will be screened at title, abstract, and full text levels, recording both the number of excluded articles and reasons for exclusion. Full text assessment will be conducted on all included article and extracted data will be reported in a narrative review that will summarize trends in the evidence, report any knowledge gaps and gluts, and provide insight for policy, practice and future research. The data from this systematic map will be made available as well, through an open access, searchable data portal and visualization tool.We are grateful for funding support from the Program on Forests (PROFOR) (SA, SO, SC, RG) and the USDA National Institute of Food and Agriculture, Hatch Project #1009327 (DM)
A systematic map of evidence on the contribution of forests to poverty alleviation
This is the final version. Available from the publisher via the DOI in this record.Background: Forests provide an essential resource to the livelihoods of an estimated 20% of the global population. The contribution of forest ecosystems and forest-based resources to poverty reduction is increasingly emphasized in international policy discourse and conservation and development investments. However, evidence measuring the effect of forest-based activities on poverty outcomes remains scattered and unclear. Lack of systematic understanding of forest-poverty relationships, in turn, inhibits research, policymaking, and efficient financial resource allocation. Methods: To identify relevant studies for inclusion in this systematic map we searched six bibliographic databases, 15 organizational websites, eight systematic evidence syntheses (reviews and maps), and solicited information from key informants. Search results were screened for relevance against predefined inclusion criteria at title, abstract, and full text levels, according to a published protocol. Included articles were coded using a predefined framework. Trends in the evidence, knowledge gaps and relatively well-researched sub-topics are reported in a narrative synthesis. Occurrence and extent of existing evidence about links between interventions and outcomes are presented in a visual heatmap. Data are available through the open access Evidence for Nature and People Data Portal (http://www.natureandpeopleevidence.org). Results: A total of 242 articles were included in the systematic map database. Included articles measured effects of 14 forest-based intervention types on 11 poverty dimensions. The majority of the evidence base (72%) examined links between productivity-enhancement strategies (e.g. forest management, agroforestry, and habitat management) and monetary income and/or social capital outcomes. Other areas with high occurrence of articles include linkages between interventions involving governance, individual rights/empowerment or linked enterprises/livelihood alternatives with impacts on monetary income from direct sale of goods. A key knowledge gap was on the impacts of investment-based interventions (i.e. enhancing produced, human, and social capitals). Another was the impacts of forest-based interventions on financial capital (savings, debt), non-monetary benefits, and health. Conclusions: The evidence base on forest-based productive activities and poverty alleviation is growing but displays a number of biases in the distribution of articles on key linkages. Priorities for future systematic reviews and evaluations include in-depth examinations into the impacts of rights-based activities (e.g. governance, empowerment) on poverty dimensions; and productivity-enhancing activities on social capital. More comprehensive and robust evidence is needed to better understand the synergies and trade-offs among the different objectives of forest conservation and management and variation in outcomes for different social groups in different social-ecological contexts
Control Barrier Functions in UGVs for Kinematic Obstacle Avoidance: A Collision Cone Approach
In this paper, we propose a new class of Control Barrier Functions (CBFs) for
Unmanned Ground Vehicles (UGVs) that help avoid collisions with kinematic
(non-zero velocity) obstacles. While the current forms of CBFs have been
successful in guaranteeing safety/collision avoidance with static obstacles,
extensions for the dynamic case with torque/acceleration-controlled unicycle
and bicycle models have seen limited success. Moreover, with these nonholonomic
UGV models, applications of existing CBFs have been conservative in terms of
control, i.e., steering/thrust control has not been possible under certain
common scenarios. Drawing inspiration from the classical use of collision cones
for obstacle avoidance in path planning, we introduce its novel CBF formulation
with theoretical guarantees on safety for both the unicycle and bicycle models.
The main idea is to ensure that the velocity of the obstacle w.r.t. the vehicle
is always pointing away from the vehicle. Accordingly, we construct a
constraint that ensures that the velocity vector always avoids a cone of
vectors pointing at the vehicle. The efficacy of this new control methodology
is experimentally verified on the Copernicus mobile robot. We further extend it
to the bicycle model and demonstrate collision avoidance under various
scenarios in the CARLA simulator.Comment: Submitted to 2023 IEEE/RSJ International Conference on Intelligent
Robots and Systems (IROS). 8 pages, 8 figures, For supplement video follow
https://youtu.be/4qWYaWEPduM. The first and second authors have contributed
equall
Sheep Associated-Malignant Catarrhal Fever: Past, present, and future
Members of Artiodactyla can contract the infectious disease Malignant Catarrhal Fever (MCF), which has a wide range of symptoms. Ten known viruses contribute to the disease, the two most significant ones being Ovine gamma herpes virus 2 (OvHV-2) and Alcelaphine gamma herpes virus 1 (AIHV-1). In the African subcontinent, AIHV-1 is seen in most MCF cases. In the Indian scenario, Ovine gamma herpes virus-2 is the main culprit. MCF is reported in certain pockets of India. Its threat to wildlife is not yet completely understood. In AIHV-1, wildebeests serve as the primary MCF reservoir, whereas with OvHV-2, the primary MCF reservoir is sheep. In India, OvHV-2 causes MCF in deer species, bison, and water buffaloe. The life cycle and properties of this virus are not yet wholly deciphered. To understand the impact of the disease and the threat it may pose in the future, we need to have diagnostic techniques in place. Currently, PCR is the most commonly used diagnostic technique. Work should be done on field-oriented tests like ELISA and LFA, which are helpful in areas without sophisticated lab facilities. Treatment protocols must be in place, as culling bovines is not an accepted policy in India. Probable plans for overcoming all these problems are discussed in this article
A DNA microarray survey of gene expression in normal human tissues
BACKGROUND: Numerous studies have used DNA microarrays to survey gene expression in cancer and other disease states. Comparatively little is known about the genes expressed across the gamut of normal human tissues. Systematic studies of global gene-expression patterns, by linking variation in the expression of specific genes to phenotypic variation in the cells or tissues in which they are expressed, provide clues to the molecular organization of diverse cells and to the potential roles of the genes. RESULTS: Here we describe a systematic survey of gene expression in 115 human tissue samples representing 35 different tissue types, using cDNA microarrays representing approximately 26,000 different human genes. Unsupervised hierarchical cluster analysis of the gene-expression patterns in these tissues identified clusters of genes with related biological functions and grouped the tissue specimens in a pattern that reflected their anatomic locations, cellular compositions or physiologic functions. In unsupervised and supervised analyses, tissue-specific patterns of gene expression were readily discernable. By comparative hybridization to normal genomic DNA, we were also able to estimate transcript abundances for expressed genes. CONCLUSIONS: Our dataset provides a baseline for comparison to diseased tissues, and will aid in the identification of tissue-specific functions. In addition, our analysis identifies potential molecular markers for detection of injury to specific organs and tissues, and provides a foundation for selection of potential targets for selective anticancer therapy
Global forces of change : implications for forest-poverty dynamics
This article examines global trends likely to influence forests and tree-based systems and considers the poverty implications of these interactions. The trends, identified through a series of expert discussions and review of the literature, include: (i) climatic impacts mediated through changes in forests, (ii) growth in commodity markets, (iii) shifts in private and public forest sector financing, (iv) technological advances and rising interconnectivity, (v) global socio-political movements, and (vi) emerging infectious diseases. These trends bring opportunities and risks to the forest-reliant poor. A review of available evidence suggests that in a business-as-usual scenario, the cumulative risks posed by these global forces, in conjunction with limited rights, resources, and skills required to prosper from global changes, are likely to place poor and transient poor households under additional stress. The article concludes with an assessment of how interventions for enhancing forest management, combined with supportive policy and institutional conditions, can contribute to a different and more prosperous future for forests and people
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