686 research outputs found
Cr-Hollandite: Breaking Tradition with Todorokite-type Manganese Oxides
The synthesis of a tunneled hollandite-type manganese oxide with interstitial and framework Cr3+ is described. This unique material is prepared from a layered buserite precursor under conditions previously believed to only yield todorokite-type manganese oxides with larger tunnels. The influence of Cr3+ in promoting the hollandite structure has been investigated by selectively placing the cation either in interstitial or framework sites. The use of framework Cr3+ in combination with other interstitial cations generates related hollandite and todorokite derivatives. Catalytic oxidation reactions with benzyl alcohol and carbon monoxide have also been examined
"I want to see a drowning-free Philippines": a qualitative study of the current situation, key challenges and future recommendations for drowning prevention in the Philippines
Drowning is described as a public health challenge by the World Health Organization. This challenge faces the Philippines where drowning claims an average of 3276 lives annually (3.50/100,000 population). However, no research comprehensively documents prevention strategies implemented by government and non-government agencies at a national or local level in the Philippines. This study aimed to qualitatively explore the current situation and key challenges of preventing drowning in the Philippines through key informant interviews and make recommendations to guide prevention efforts. Interviews were conducted among government and non-government agencies involved in drowning prevention using purposive sampling. Qualitative data collected were thematically analyzed. Findings indicate government and non-government agencies implement drowning prevention programs or strategies based on the mandate of their institutions. Most commonly cited were activities related to education or information awareness, emergency and disaster preparedness, and swimming skills. It was revealed that each agency was relatively unaware of the drowning prevention programs of other agencies. A multisector approach is needed to develop coordinated and comprehensive programs and activities aimed at preventing drowning. In this way, duplication will be avoided and the minimal resources available will be used effectively to reduce the burden of drowning in the Philippines
Application of the PRECEDE-PROCEED model in the development of evidence-informed interventions for drowning prevention: a mixed-methods study protocol
Introduction Drowning is a global public health threat, disproportionately impacting low-income and middle-income countries. In the Philippines, it is estimated that more than 5200 people die from drowning per annum. This number is likely to be higher than currently estimated with the inclusion of disaster-related and transportation-related drowning. Drowning is preventable if appropriate preventive interventions are put in place which redress known risk factors. Methods and analysis This study uses the PRECEDE-PROCEED model (PPM), an eight-step health promotion planning and evaluation model for building and improving intervention programmes. This mixed-methods study, which can be used in any location, will be implemented in Los BaĂ
os, Laguna, Philippines, identified as an area of concern for drowning. Using the PPM, data on drowning will be collected from death records, community observation, key informant interviews, focus group discussions and community survey. A range of analytical methods will be used to explore drowning data including univariate and Ï 2 analyses, analysis of variance, relative risk and calculating rates using population data. The quantitative data and themes drawn from qualitative data will be used to populate the first four phases of the PPM. Following the data collection, the remaining stages of the PPM will be designed and implemented in the barangay (village) with the highest drowning rate. Ethics and dissemination This study has obtained ethical clearance from the University of the Philippines Manila Research Ethics Board (UPMREB 2017-425-01). Study findings will be disseminated through workshops and presentations to the local community as well as through peer-reviewed literature and conference presentations. The PPM has rarely been applied to drowning prevention and it is the aim that the study described in this protocol is expanded across other areas of the Philippines and to other countries with a high drowning burden to inform prevention efforts
The role of stress and fluid saturation on the acoustic response of fractured rock
Standard rock physics models are formulated to describe the behavior of porous sedimentary reservoirs, with clean sandstones being the archetypal system; however, many situations demand geophysical monitoring of rocks with significantly different structures, such as low porosity, fractured reservoirs. Conventional models also suggest that these âstiffâ reservoirs can be challenging to monitor seismically due to small fluid substitution effects, but the presence of fractures leads to stress dependence which may be leveraged for remote monitoring purposes. Using samples from the Duperow Formation (dolostone) obtained from the Danielson test well in Kevin Dome, MT, we conducted ultrasonic and multi-scale structural (profilometry, synchrotron micro-tomography, pressure sensitive film) measurements on naturally fractured core in order to characterize the effects of fluid substitution and effective stress on the acoustic response of fractured reservoir rock with a focus in particular on the textural and seismic characteristics of natural fractures. We find that changes in effective stress can yield changes in velocity of up to 20% and changes in attenuation up to 200%. Measured fluid substitution effects are resolvable, but stress effects dominate. These measurements provide insight into the physical processes controlling acoustic response of fractured rocks in general and can also be used to inform monitoring efforts in fractured reservoirs
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Validation of reference tissue modelling for [11C]flumazenil positron emission tomography following head injury.
OBJECTIVE: [(11)C]Flumazenil ([(11)C]FMZ) positron emission tomography (PET) can be used as a measure of neuronal loss. The purpose of this study was to validate reference tissue kinetic modelling of [(11)C]FMZ PET within a group of patients with head injury. METHODS: Following earlier studies, the pons was used as the reference region. PET scans were performed on 16 controls and 11 patients at least 6 months following injury, each of whom also had arterial blood sampling to provide whole blood and metabolite-corrected plasma input functions. Regional non-displaceable binding potentials (BP(ND)) were calculated from five reference tissue models and compared to BP(ND) from arterial input models. For the patients, the regions included a peri-lesional region of interest (ROI). RESULTS: Total distribution volume of the pons was not significantly different between control and patient groups (P = 0.24). BP(ND) from all the reference tissue approaches correlated well with BP(ND) from the plasma input models for both controls (r (2) = 0.98-1.00; P < 0.001) and patients (r (2) = 0.99-1.00; P < 0.001). For the peri-lesional regions (n = 11 ROI values), the correlation was also high (r (2) = 0.91). CONCLUSIONS: These results indicate that reference tissue modelling with the pons as the reference region is valid for [(11)C]FMZ PET in head-injured patients at 6 months following injury within both normal appearing and peri-lesional brain regions
Improved Tests of Relations for Baryon Isomultiplet Splittings
The least well-known octet baryon mass is MeV.
The prospect of an improved measurement of its mass by the KTeV experimental
program at Fermilab, and opportunities for improvements in charged and excited
hyperon and mass measurements, makes it timely to re-examine
descriptions of isospin splittings in baryons containing light quarks. It is
possible by examining such relations as the Coleman-Glashow relation to distinguish between
those models making use of one- or two-body effects involving quarks and those
involving genuine three-body effects. A hierarchy based on an expansion in
, where is the number of quark colors, is useful in this respect.
The present status of other quark-model mass relations involving mixing and the baryon decuplet is also noted, and the degree to which
one can determine parameters such as quark mass differences and individual
electromagnetic contributions to splittings is discussed.Comment: 16 pages, LaTeX, no figures. Revised February 1998: further text and
reference
Preventing child drowning in the Philippines: the need to address the determinants of health
Drowning is a public health issue in the Philippines, with children at significantly increased risk. Determinants of health (DoH) such as education, socio-economic status, ethnicity, and urbanization are factors that impact drowning risk. As drowning is a multisectoral issue, a national drowning prevention plan can drive collaboration with relevant stakeholders. This study reports trends in unintentional child (0â14 years) drowning in the Philippines (incidence, rates, and trends over time for fatal and non-fatal (years lived with a disability (YLDs) and disability adjusted life years (DALYs) from 2008â2017 and conducts an analysis of the Philippinesâ Multisector Action Plan (MSAP) on Drowning Prevention. From 2008â2017, 27,928 (95%UI [Uncertainty Interval]: 22,794â33,828) children aged 0â14 years died from drowning (52.7% aged 5â14 years old). Rates of drowning have declined among both age groups, with greater reductions seen among 0â4 year olds (y = â0.3368x + 13.035; R2 = 0.9588). The MSAP has 12 child drowning-specific activities and 20 activities were identified where DoH will need to be considered during development and implementation. The MSAP activities, and work done to prevent drowning more generally, must consider DoH such as education, urbanization, water and sanitation health, and safe water transportation. A national drowning surveillance system and investment in research in the Philippines are recommended
Synaptic Loss in Primary Tauopathies Revealed by [11 C]UCB-J Positron Emission Tomography.
BACKGROUND: Synaptic loss is a prominent and early feature of many neurodegenerative diseases. OBJECTIVES: We tested the hypothesis that synaptic density is reduced in the primary tauopathies of progressive supranuclear palsy (PSP) (Richardson's syndrome) and amyloid-negative corticobasal syndrome (CBS). METHODS: Forty-four participants (15 CBS, 14 PSP, and 15 age-/sex-/education-matched controls) underwent PET with the radioligand [11 C]UCB-J, which binds to synaptic vesicle glycoprotein 2A, a marker of synaptic density; participants also had 3 Tesla MRI and clinical and neuropsychological assessment. RESULTS: Nine CBS patients had negative amyloid biomarkers determined by [11 C]PiB PET and hence were deemed likely to have corticobasal degeneration (CBD). Patients with PSP-Richardson's syndrome and amyloid-negative CBS were impaired in executive, memory, and visuospatial tasks. [11 C]UCB-J binding was reduced across frontal, temporal, parietal, and occipital lobes, cingulate, hippocampus, insula, amygdala, and subcortical structures in both PSP and CBD patients compared to controls (P <â0.01), with median reductions up to 50%, consistent with postmortem data. Reductions of 20% to 30% were widespread even in areas of the brain with minimal atrophy. There was a negative correlation between global [11 C]UCB-J binding and the PSP and CBD rating scales (R = -0.61, P <â0.002; R = -0.72, P <â0.001, respectively) and a positive correlation with the revised Addenbrooke's Cognitive Examination (R = 0.52; P =â0.01). CONCLUSIONS: We confirm severe synaptic loss in PSP and CBD in proportion to disease severity, providing critical insight into the pathophysiology of primary degenerative tauopathies. [11 C]UCB-J may facilitate treatment strategies for disease-modification, synaptic maintenance, or restoration. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
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