678 research outputs found

    Photometric and spectroscopic gamma-ray observations of solar transient phenomena using long duration balloons

    Get PDF
    A program currently in progress to conduct extended duration spectroscopic and photometric observation of solar X-ray phenomena from balloons is described. High photometric sensitivity to weak hard X-ray bursts is attained using a 600 sq cm array of phoswich scintillators. High spectral resolution for stronger bursts is available from an array of planar germanium detectors. These instruments are carried in a novel balloon gondola dssigned for the 15 to 20 day float durations available through using conventional zero pressure balloons in the radiation controlled (RACOON) mode

    A high-resolution gamma-ray and hard X-ray spectrometer for solar flare observations in Max 1991

    Get PDF
    A long duration balloon flight instrument for Max 1991 designed to study the acceleration of greater than 10 MeV ions and greater than 15 keV electrons in solar flares through high resolution spectroscopy of the gamma ray lines and hard X-ray and gamma ray continuum is described. The instrument, HIREGS, consists of an array of high-purity, n-type coaxial germanium detectors (HPGe) cooled to less than 90 K and surrounded by a bismuth germanate (BGO) anticoincidence shield. It will cover the energy range 15 keV to 20 MeV with keV spectral resolution, sufficient for accurate measurement of all parameters of the expected gamma ray lines with the exception of the neutron capture deuterium line. Electrical segmentation of the HPGe detector into a thin front segment and a thick rear segment, together with pulse-shape discrimination, provides optimal dynamic range and signal-to-background characteristics for flare measurements. Neutrons and gamma rays up to approximately 0.1 to 1 GeV can be detected and identified with the combination of the HPGe detectors and rear BGO shield. The HIREGS is planned for long duration balloon flights (LDBF) for solar flare studies during Max 1991. The two exploratory LDBFs carried out at mid-latitudes in 1987 to 1988 are described, and the LDBFs in Antarctica, which could in principle provide 24 hour/day solar coverage and very long flight durations (20 to 30 days) because of minimal ballast requirements are discussed

    Communicating risk from the frontline: projecting community voices into disaster risk management policies across scales, in: Urban Ark Briefing No 19. October 2018

    Get PDF
    Research carried out in Dar es Salaam, Tanzania on cross-scalar risk communication and disaster risk governance reveals that, while there is considerable potential for communities to measure and communicate risk and to prioritise actions, there is little scope for them to influence disaster risk governance at this point in time. This is partly because, although disaster risk management (DRM) is devolved in Tanzania, it has not gone far enough to give adequate powers and financing to the lowest level of government at the sub-wards, which are at the frontline of managing the biggest everyday risks that people face. The effective communication of risks upwards from communities to governments, and of DRM policies and opportunities downwards to communities and across sectors is crucial to overcome these gaps. When communication is participatory and collaborative, there is scope for local city actors to reflect on the need for action to be joined across governance scales, and to ensure communication plays a key role at and between all levels

    COVID-19 as a global challenge: towards an inclusive and sustainable future

    Get PDF
    COVID-19 is a global challenge that demands researchers, policy makers, and governments address multiple dimensions which go far beyond the implications of this pandemic for health and wellbeing. Just as the UN Sustainable Development Goals call for focus on the connections between development policy sectors, the pandemic has exposed the complex global interdependencies that underpin economies and highlighted fault lines in societal structures that perpetuate ethnic, economic, social, and gender inequalities. Here, we highlight the pandemic's emerging potential consequences for achieving sustainable development with respect to the six global challenge areas we collectively address at the UK Research and Innovation's Global Challenges Research Fund:1 food systems; education; cities and sustainable infrastructure; security, protracted conflict, refugee crises, and forced displacement; environmental resilience; and global health. As the immediate health consequences of the pandemic unfold and begin to be superseded by the impact of public health containment measures, we call for a refocusing of research and action not only to mitigate these impacts but to build sustainability and strengthened resilience into future recovery

    Advanced techniques for high resolution spectroscopic observations of cosmic gamma-ray sources

    Get PDF
    An advanced gamma-ray spectrometer that is currently in development is described. It will obtain a sensitivity of 0.0001 ph/sq cm./sec in a 6 hour balloon observation and uses innovative techniques for background reduction and source imaging

    Global tidal impacts of large-scale ice-sheet collapses

    Get PDF
    Tide model output for "Wilmes et al., (2017), Global tidal impacts of large-scale ice-sheet collapses, JGR Oceans" together with the Matlab files needed to read the model binary files Please refer to the publications for details on the run setup. h0.* contains elevation output; M2 elevations can be read in Matlab using [h,th_lim,ph_lim] = h_in(filename,1); where h is tidal elevation (abs(h) gives amplitudes and angle(h) gives phase), th_lim gives latitude limits in degs N and ph_lim longitude limits in degs E u0.* contains tidal transport output; M2 transports can be read in Matlab using [u,v,th_lim,ph_lim] = u_in(filename,1); where u and v are transports in x and y direction (real(u)/hz gives tidal current strength) grid* contains the bathymetry; can be read in Matlab using [ll_lims,hz,mz,iob] = grd_in(filename); where ll_lims gives lon and lat limits, hz is water depth, mz is the land-sea mask (0 is land, 1 is water), and iob are open boundary nodes *.it_m2_k1_00.0kyrBP_ish_no0.1sal_191322_sal4 - CTRL; bathymetry: grid_etssib_1_8_paleo_glob_ice_shelves *.it_m2_k1_00.0kyrBP_ish_5mSLR_vw_no0.1sal_191333_sal4 - 5m SLR; bathymetry: grid_etssib_1_8_paleo_glob_ice_shelves_5mSLR_vw *.it_m2_k1_00.0kyrBP_ish_7mSLR_vw_no0.1sal_191336_sal4 - 7m SLR; bathymetry: grid_etssib_1_8_paleo_glob_ice_shelves_7mSLR_vw *.it_m2_k1_1_8th_00.0kyrBP_12mSLR_vw_7048752_sal4 - 12m SLR; bathymetry: grid_etssib_1_8_paleo_glob_ice_shelves_12mSLR_vw *.it_m2_k1_00.0kyrBP_no_wais_fp_5mSLR_vw_no0.1sal_191326_sal4 - No WAIS; bathymetry: grid_etssib_1_8_glob_no_wais_SLR_fingerprint_5m_EEV_vw *.it_m2_k1_00.0kyrBP_no_gris_fp_7mSLR_vw_no0.1sal_191331_sal4 - No GIS; bathymetry: grid_etssib_1_8_glob_no_gris_SLR_fingerprint_7m_EEV_vw *.it_m2_00.0kyrBP_no_wais_gis_fp_vw_375526_sal4 - No WAIS & No GIS; bathymetry: grid_etssib_1_8_glob_no_wais_gris_SLR_fingerprint_12m_EEV_v

    Uncertain pasts and risk-sensitive futures in sub-Saharan urban transformation

    Get PDF
    This chapter explores the status and the scope for transition of risk- sensitive and transformative urban development in diverse cities of sub-Saharan Africa. Sub-Saharan Africa is important because of its large proportions of urban populations with high vulnerability and growing exposure to risks. High rates of urban growth pose increasing risks as we go into the future, yet there is also opportunity to reduce risk through integrating risk management into development. However, this opportunity space is often constrained by limited capacities to plan and manage the rapid urbanisation process, particularly in informal settlements. Limited capacities to prevent processes of risk accumulation pose threats to poverty reduction and sustainable development. In this context, there is an increasingly urgent need for squarely recognising and addressing the underlying vulnerabilities of urban populations and their root causes. Transitioning towards such sustainable urban pathways will require the strengthening of capacities and accountability of city authorities and broader governance systems, both formal and informal

    Bacterial biofilm formation on indwelling urethral catheters

    Get PDF
    Urethral catheters are the most commonly deployed medical devices and used to manage a wide range of conditions in both hospital and community care settings. The use of long-term catheterization, where the catheter remains in place for a period &gt;28 days remains common, and the care of these patients is often undermined by the acquisition of infections and formation of biofilms on catheter surfaces. Particular problems arise from colonization with urease-producing species such as Proteus mirabilis, which form unusual crystalline biofilms that encrust catheter surfaces and block urine flow. Encrustation and blockage often lead to a range of serious clinical complications and emergency hospital referrals in long-term catheterized patients. Here we review current understanding of bacterial biofilm formation on urethral catheters, with a focus on crystalline biofilm formation by P. mirabilis, as well as approaches that may be used to control biofilm formation on these devices. Significance and Impact of the Study: Urinary catheters are the most commonly used medical devices in many healthcare systems, but their use predisposes to infection and provide ideal conditions for bacterial biofilm formation. Patients managed by long-term urethral catheterization are particularly vulnerable to biofilm-related infections, with crystalline biofilm formation by urease producing species frequently leading to catheter blockage and other serious clinical complications. This review considers current knowledge regarding biofilm formation on urethral catheters, and possible strategies for their control.</p

    Water Management Decision Making in the Face of Multiple Forms of Uncertainty and Risk

    Get PDF
    In the Wasatch Range Metropolitan Area of Northern Utah, water management decision makers confront multiple forms of uncertainty and risk. Adapting to these uncertainties and risks is critical for maintaining the long‐term sustainability of the region\u27s water supply. This study draws on interview data to assess the major challenges climatic and social changes pose to Utah\u27s water future, as well as potential solutions. The study identifies the water management adaptation decision‐making space shaped by the interacting institutional, social, economic, political, and biophysical processes that enable and constrain sustainable water management. The study finds water managers and other water actors see challenges related to reallocating water, including equitable water transfers and stakeholder cooperation, addressing population growth, and locating additional water supplies, as more problematic than the challenges posed by climate change. Furthermore, there is significant disagreement between water actors over how to best adapt to both climatic and social changes. This study concludes with a discussion of the path dependencies that present challenges to adaptive water management decision making, as well as opportunities for the pursuit of a new water management paradigm based on soft‐path solutions. Such knowledge is useful for understanding the institutional and social adaptations needed for water management to successfully address future uncertainties and risks

    Conceptualizing community resilience to natural hazards - the emBRACE framework

    Get PDF
    Abstract. The level of community is considered to be vital for building disaster resilience. Yet, community resilience as a scientific concept often remains vaguely defined and lacks the guiding characteristics necessary for analysing and enhancing resilience on the ground. The emBRACE framework of community resilience presented in this paper provides a heuristic analytical tool for understanding, explaining and measuring community resilience to natural hazards. It was developed in an iterative process building on existing scholarly debates, on empirical case study work in five countries and on participatory consultation with community stakeholders, where the framework was applied and ground-tested in different contexts and for different hazard types. The framework conceptualizes resilience across three core domains: resources and capacities; actions; and learning. These three domains are conceptualized as intrinsically conjoined within a whole. Community resilience is influenced by these integral elements as well as by extra-community forces, comprising disaster risk governance and thus laws, policies and responsibilities on the one hand and on the other, the general societal context, natural and human-made disturbances and system change over time. The framework is a graphically rendered heuristic, which through application can assist in guiding the assessment of community resilience in a systematic way and identifying key drivers and barriers of resilience that affect any particular hazard-exposed community
    corecore