739 research outputs found

    Lessons Learned: Case Studies in Sustainable Use, Conclusion

    Get PDF
    The conclusion of Lessons Learned: Case Studies in Sustainable Use summarizes the overarching lessons learned from the case studies provided in the volume. 1. Sustainability of uses of renewable natural resources is dependent on the existence of a 'sustainable society'at the local, national and global levels. 2. Successful biological conservation is a function of equity and democracy. 3. To achieve greater sustainability of uses of natural resources will likely require modification of the roles of organizations and government agencies in authority. 4. The current conservation paradigm of Protected Areas (including as applied to the 'biodiversity hotspots'concept) may not be economically viable in many developing countries, simply because the opportunitycosts often exceed the value local people receive from their existence. National and international agencies and organizations realize most of the value from designation of protected areas and 'hotspots'. 5. It is not possible to transpose directly the combination of factors that influence one case to another site, and expect the same impact or result.6. Donor agencies and/or central government policies need to consider management requirements beyond project cycles in order to promote long-term sustainability of resource uses.7. External factors such as war and natural disasters can have an over-riding influence on the sustainability of resource use. 8. Interventions on key resources by external institutions often pressure transformation of local governance systems. The impact of these changes is often overlooked. More specific observations of common features. Furthermore, the conclusion provides lessons related to policy, social processes, institutions, and information

    Drop Impact on Liquid Surfaces: Formation of Lens and Spherical Drops at the Air-Liquid Interface

    Full text link
    Droplets at the air-liquid interface of immiscible liquids usually form partially-submerged lens shapes (e.g. water on oil). In addition to this structure, we showed that droplets released from critical heights above the target liquid can sustain the impact and at the end maintain a spherical ball-shape configuration above the surface, despite undergoing large deformation. Spherical drops are unstable and will transform into the lens mode due to slight disturbances. Precision dispensing needles with various tip diameter sizes were used to release pendant drops of deionized water onto the surface of fluorocarbon liquid (FC-43, 3M). A cubic relationship was found between the nozzle tip diameter and the released droplet diameter. Drop impact was recorded by a high speed camera at a rate of 2000 frames per second. In order for the water drops to sustain the impact and retain a spherical configuration at the surface of the target liquid pool, it is required that they be of a critical size and be released from a certain height; otherwise the commonly observed lens shape droplets will form at the surface

    Elastic uplift in southeast Greenland due to rapid ice mass loss

    Get PDF
    This is the publisher's version, also available electronically from "http://onlinelibrary.wiley.com".[1] The rapid unloading of ice from the southeastern sector of the Greenland ice sheet between 2001 and 2006 caused an elastic uplift of ∼35 mm at a GPS site in Kulusuk. Most of the uplift results from ice dynamic-induced volume losses on two nearby outlet glaciers. Volume loss from Helheim Glacier, calculated from sequential digital elevation models, contributes about ∼16 mm of the observed uplift, with an additional ∼5 mm from volume loss of Kangerdlugssuaq Glacier. The remaining uplift signal is attributed to significant melt-induced ice volume loss from the ice sheet margin along the southeast coast between 62°N and 66°N

    Lessons Learned: Case Studies in Sustainable Use, Preface Page

    Get PDF
    This preface page of the volume Lessons Learned: Case Studies in Sustainable Use, provides a summary of the book's purpose and structure. Enhancing sustainability requires a multidisciplinary approach. Because there is such diversity in resources, uses, and users, there is no universal formula, yet to promote, or assess, practices in context is essential. Without this capacity approaches to sustainable use will remain superficial and ineffective.The present volume presents six detailed cases of uses of different facets of biological diversity in Africa (East, West and Southern), Central Asia and South America-Latin America;. The objective of the project was to identify 'Lessons Learned' from examples of sustainable use. To address this objective, six cases were selected because they had been implemented for several years and they were being implemented in different regions, thus enhancing the potential for identifying key lessons. Each of the case studies was examined using an 'Analytic Framework for Assessing the Factors that Influence Sustainability of Uses of Wild Living Natural Resources' The Analytic Framework (Annex 1) provided a consistent, systematic approach to the analysis of the cases according to 'domains of issues' considered important in assessing sustainability, including inter alia, ecological processes and functions, economic factors, societal and institutional factors

    Modelled glacier dynamics over the last quarter of a century at Jakobshavn Isbræ

    Get PDF
    Observations over the past 2 decades show substantial ice loss associated with the speed-up of marine-terminating glaciers in Greenland. Here we use a regional three-dimensional outlet glacier model to simulate the behaviour of Jakobshavn Isbræ (JI) located in western Greenland. Our approach is to model and understand the recent behaviour of JI with a physical process-based model. Using atmospheric forcing and an ocean parametrization we tune our model to reproduce observed frontal changes of JI during 1990–2014. In our simulations, most of the JI retreat during 1990–2014 is driven by the ocean parametrization used and the glacier's subsequent response, which is largely governed by bed geometry. In general, the study shows significant progress in modelling the temporal variability of the flow at JI. Our results suggest that the overall variability in modelled horizontal velocities is a response to variations in terminus position. The model simulates two major accelerations that are consistent with observations of changes in glacier terminus. The first event occurred in 1998 and was triggered by a retreat of the front and moderate thinning of JI prior to 1998. The second event, which started in 2003 and peaked in the summer 2004, was triggered by the final break-up of the floating tongue. This break-up reduced the buttressing at the JI terminus that resulted in further thinning. As the terminus retreated over a reverse bed slope into deeper water, sustained high velocities over the last decade have been observed at JI. Our model provides evidence that the 1998 and 2003 flow accelerations are most likely initiated by the ocean parametrization used but JI's subsequent dynamic response was governed by its own bed geometry. We are unable to reproduce the observed 2010–2012 terminus retreat in our simulations. We attribute this limitation to either inaccuracies in basal topography or to misrepresentations of the climatic forcings that were applied. Nevertheless, the model is able to simulate the previously observed increase in mass loss through 2014

    Pediatric Bacterial Meningitis Surveillance in Niger: Increased Importance of Neisseria meningitidis Serogroup C, and a Decrease in Streptococcus pneumoniae Following 13-Valent Pneumococcal Conjugate Vaccine Introduction.

    Get PDF
    BACKGROUND: Meningitis is endemic in Niger. Haemophilus influenzae type b (Hib) vaccine and the 13-valent pneumococcal conjugate vaccine (PCV13) were introduced in 2008 and 2014, respectively. Vaccination campaign against Neisseria meningitidis serogroup A was carried out in 2010-2011. We evaluated changes in pathogen distribution using data from hospital-based surveillance in Niger from 2010 through 2016. METHODS: Cerebrospinal fluid (CSF) specimens from children <5 years old with suspected meningitis were tested to detect vaccine-preventable bacterial pathogens. Confirmatory identification and serotyping/grouping of Streptococcus pneumoniae, N. meningitidis, and H. influenzae were done. Antimicrobial susceptibility testing and whole genome sequencing were performed on S. pneumoniae isolates. RESULTS: The surveillance included 2580 patients with suspected meningitis, of whom 80.8% (2085/2580) had CSF collected. Bacterial meningitis was confirmed in 273 patients: 48% (131/273) was N. meningitidis, 45% (123/273) S. pneumoniae, and 7% (19/273) H. influenzae. Streptococcus pneumoniae meningitis decreased from 34 in 2014, to 16 in 2016. PCV13 serotypes made up 88% (7/8) of S. pneumoniae meningitis prevaccination and 20% (5/20) postvaccination. Neisseria meningitidis serogroup C (NmC) was responsible for 59% (10/17) of serogrouped N. meningitidis meningitis. Hib caused 67% (2/3) of the H. influenzae meningitis isolates serotyped. Penicillin resistance was found in 16% (4/25) of S. pneumoniae isolates. Sequence type 217 was the most common lineage among S. pneumoniae isolates. CONCLUSIONS: Neisseria meningitidis and S. pneumoniae remain important causes of meningitis in children in Niger. The decline in the numbers of S. pneumoniae meningitis post-PCV13 is encouraging and should continue to be monitored. NmC is the predominant serogroup causing N. meningitidis meningitis
    • …
    corecore