272 research outputs found
Pathophysiological aspects of severe Falciparum malaria in Thailand and Ghana
The mechanisms of parasite clearance in falciparum malaria are still unclear but the spleen is considered to be the major site of parasite removal. The process of removing intraerythrocytic parasites leaving the host erythrocyte intact is termed "pitting". We have investigated several possible mechanisms for parasite clearance. Using monoclonal antibodies to Ring Erythrocyte Surface antigen, (RESA or Pf 155) an early antigen expressed on the erythrocyte surface and staining for intraerythrocytic plasmodial DNA we have demonstrated that removal of intracellular parasites by host phagocytes leaving the erythrocyte intact, occurs in vivo. During acute falciparum malaria infection, red blood cells (RBC) containing abundant RESA, but no intracellular parasites, are present in the circulation. These RESA-positive parasite-negative RBC are not seen in parasite cultures in vitro. This indicates that in acute falciparum malaria there is active removal of intra-erythrocytic parasites by a host mechanism in vivo (probably the spleen) without destruction of the parasitized RBC. The ability of parasites to form rosettes has been considered a marker of pathogenicity in malaria and those parasites with a greater potential for this phenomenon were considered inherently more pathogenic. We have reported rosetting in a Thai patient with Plasmodium ovale infection suggesting that rosetting is in fact a common property of all plasmodia. Using a laser diffraction technique, we measured red blood cell (RBC) deformability over a range of shear stresses and related this to the severity of anemia in 36 adults with severe falciparum malaria. The RBC deformability at a high shear stress of 30 Pa, similar to that encountered in the splenic sinusoids, showed a significant positive correlation with the nadir hemoglobin concentration during hospitalization (r = 0.49, P < 0.002). Reduction in RBC deformability resulted mainly from changes in non-parasitised erythrocytes. Since reduced red blood cell deformability (RBC-D) can also contribute to impaired microcirculatory flow, RBC-D was measured and compared in 23 patients with severe falciparum malaria (seven of whom subsequently died), 30 patients with uncomplicated malaria, and 17 healthy controls. The RBC-D was significantly reduced in severe malaria and was particularly low in all fatal cases. At a low shear stress of 1.7 Pascal (Pa), a red blood cell elongation index less than 0.21 on admission to the hospital predicted fatal outcome with a sensitivity of 100% (confidence interval [Cl] 59 - 100%) and a specificity of 88% (Cl = 61 - 98%). The reduction in the RBC- D appeared to result mainly from changes in unparasitized erythrocytes. This finding may provide a rationale for the use of exchange transfusion in severe malaria since this process will replace rigid cells with more deformable cells. (Abstract shortened by ProQuest.)
Excavations at Gournia, 2010-2012
This article presents previous research at Gournia, the overall goals of our project, a new plan of the settlement, and our 2010-2012 excavations in eight areas: the Pit House, the Northwest Area, the North Cemetery, North Trench, the Northeast Area, House Aa, several rooms in the palace, and House He. Analytical sections discuss the textual evidence; the painted plasters; and the botanical remains. Our excavations indicate that Gournia was first settled in the Final Neolithic period and grew into an industrial town by the Protopalatial period. Following a Middle Minoan II destruction, the town was reorganized in Middle Minoan IIIA to include the palace, which in Late Minoan IB employed Linear A
Getting shot of elves: healing, witchcraft and fairies in the Scottish witchcraft trials
This paper re-examines the evidence of the Scottish witchcraft trials for beliefs associated by scholars with "elf-shot." Some supposed evidence for elf-shot is dismissed, but other material illuminates the interplay between illness, healing and fairy-lore in early modern Scotland, and the relationship of these beliefs to witchcraft itself
Understanding the treatment benefit of hyperimmune anti-influenza intravenous immunoglobulin (Flu-IVIG) for severe human influenza
Background: Antibody-based therapies for respiratory viruses are of increasing importance. The INSIGHT 006 trial administered anti-influenza hyperimmune intravenous immunoglobulin (Flu-IVIG) to patients hospitalized with influenza. Flu-IVIG treatment improved outcomes in patients with influenza B but showed no benefit for influenza A.
Methods: To probe potential mechanisms of Flu-IVIG utility, sera collected from patients hospitalized with influenza A or B viruses (IAV or IBV) were analyzed for antibody isotype/subclass and Fcγ receptor (FcγR) binding by ELISA, bead-based multiplex, and NK cell activation assays.
Results: Influenza-specific FcγR-binding antibodies were elevated in Flu-IVIG–infused IBV- and IAV-infected patients. In IBV-infected participants (n = 62), increased IgG3 and FcγR binding were associated with more favorable outcomes. Flu-IVIG therapy also improved the odds of a more favorable outcome in patients with low levels of anti-IBV Fc-functional antibody. Higher FcγR-binding antibody was associated with less favorable outcomes in IAV-infected patients (n = 50), and Flu-IVIG worsened the odds of a favorable outcome in participants with low levels of anti-IAV Fc-functional antibody.
Conclusion: These detailed serological analyses provide insights into antibody features and mechanisms required for a successful humoral response against influenza, suggesting that IBV-specific, but not IAV-specific, antibodies with Fc-mediated functions may assist in improving influenza outcome. This work will inform development of improved influenza immunotherapies
The Organic Food Premium: A Local Assessment in the UK
The present study combines stated and revealed preferences in order to estimate the hypothetical bias of a sample of organic food consumers from Canterbury in the UK. It uses contingent valuation and hedonic pricing to compare stated and revealed preferences and employs the Almost Ideal Demand System to estimate the elasticity of organic products. The results show that the average price premium is fairly large (approximately 10%). They also demonstrate, crucially, that the size of this estimate is encouragingly similar whether a willingness-to-pay or hedonic pricing method is used. The estimated elasticity of organic products is on average above one, suggesting an elastic response to pricing policy in the present sample. Desirable next steps and potential policy applications for future research are also discussed
Challenges, solutions and research priorities for sustainable rangelands
Australia’s rangeland communities, industries, and environment are under increasing pressures from anthropogenic activities and global changes more broadly. We conducted a horizon scan to identify and prioritise key challenges facing Australian rangelands and their communities, and outline possible avenues to address these challenges, with a particular focus on research priorities. We surveyed participants of the Australian Rangeland Society 20th Biennial Conference, held in Canberra in September 2019, before the conference and in interactive workshops during the conference, in order to identify key challenges, potential solutions, and research priorities. The feedback was broadly grouped into six themes associated with supporting local communities, managing natural capital, climate variability and change, traditional knowledge, governance, and research and development. Each theme had several sub-themes and potential solutions to ensure positive, long-term outcomes for the rangelands. The survey responses made it clear that supporting ‘resilient and sustainable rangelands that provide cultural, societal, environmental and economic outcomes simultaneously’ is of great value to stakeholders. The synthesis of survey responses combined with expert knowledge highlighted that sustaining local communities in the long term will require that the inherent social, cultural and natural capital of rangelands are managed sustainably, particularly in light of current and projected variability in climate. Establishment of guidelines and approaches to address these challenges will benefit from: (i) an increased recognition of the value and contributions of traditional knowledge and practices; (ii) development of better governance that is guided by and benefits local stakeholders; and (iii) more funding to conduct and implement strong research and development activities, with research focused on addressing critical knowledge gaps as identified by the local stakeholders. This requires strong governance with legislation and policies that work for the rangelands. We provide a framework that indicates the key knowledge gaps and how innovations may be implemented and scaled out, up and deep to achieve the resilience of Australia’s rangelands. The same principles could be adapted to address challenges in rangelands on other continents, with similar beneficial outcomes
Different paths to the modern state in Europe: the interaction between domestic political economy and interstate competition
Theoretical work on state formation and capacity has focused mostly on early modern Europe and on the experience of western European states during this period. While a number of European states monopolized domestic tax collection and achieved gains in state capacity during the early modern era, for others revenues stagnated or even declined, and these variations motivated alternative hypotheses for determinants of fiscal and state capacity. In this study we test the basic hypotheses in the existing literature making use of the large date set we have compiled for all of the leading states across the continent. We find strong empirical support for two prevailing threads in the literature, arguing respectively that interstate wars and changes in economic structure towards an urbanized economy had positive fiscal impact. Regarding the main point of contention in the theoretical literature, whether it was representative or authoritarian political regimes that facilitated the gains in fiscal capacity, we do not find conclusive evidence that one performed better than the other. Instead, the empirical evidence we have gathered lends supports to the hypothesis that when under pressure of war, the fiscal performance of representative regimes was better in the more urbanized-commercial economies and the fiscal performance of authoritarian regimes was better in rural-agrarian economie
Creativity and commerce: Michael Klinger and new film history
The crisis in film studies and history concerning their legitimacy and objectives has provoked a reinvigoration of scholarly energy in historical enquiry. 'New film history' attempts to address the concerns of historians and film scholars by working self-reflexively with an expanded range of sources and a wider conception of 'film' as a dynamic set of processes rather than a series of texts. The practice of new film history is here exemplified through a detailed case study of the independent British producer Michael Klinger (active 1961-87) with a specific focus on his unsuccessful attempt to produce a war film, Green Beach, based on a memoir of the Dieppe raid (August 1942). This case study demonstrates the importance of analysing the producer's role in understanding the complexities of film-making, the continual struggle to balance the competing demands of creativity and commerce. In addition, its subject matter - an undercover raid and a Jewish hero - disturbed the dominant myths concerning the Second World War, creating what turned out to be intractable ideological as well as financial problems. The paper concludes that the concerns of film historians need to engage with broader cultural and social histories. © 2010 Taylor & Francis
A pragmatic, multicentre, randomised controlled trial comparing stapled haemorrhoidopexy to traditional excisional surgery for haemorrhoidal disease (eTHoS): study protocol for a randomised controlled trial
Background: Current interventions for haemorrhoidal disease include traditional haemorrhoidectomy (TH) and
stapled haemorrhoidopexy (SH) surgery. However, uncertainty remains as to how they compare from a clinical,
quality of life (QoL) and economic perspective. The study is therefore designed to determine whether SH is more
effective and more cost-effective, compared with TH.
Methods/Design: eTHoS (either Traditional Haemorrhoidectomy or Stapled Haemorrhoidopexy for Haemorrhoidal
Disease) is a pragmatic, multicentre, randomised controlled trial. Currently, 29 secondary care centres are open to
recruitment. Patients, aged 18 year or older, with circumferential haemorrhoids grade II to IV, are eligible to take part.
The primary clinical and economic outcomes are QoL profile (area under the curve derived from the EuroQol Group’s 5
Dimension Health Status Questionnaire (EQ-5D) at all assessment points) and incremental cost per quality adjusted life
year (QALY) based on the responses to the EQ-5D at 24 months. The secondary outcomes include a comparison of the
SF-36 scores, pain and symptoms sub-domains, disease recurrence, complication rates and direct and indirect costs
to the National Health Service (NHS). A sample size of n =338 per group has been calculated to provide 90% power
to detect a difference in the mean area under the curve (AUC) of 0.25 standard deviations derived from EQ-5D
score measurements, with a two-sided significance level of 5%. Allowing for non-response, 400 participants will
be randomised per group. Randomisation will utilise a minimisation algorithm that incorporates centre, grade of
haemorrhoidal disease, baseline EQ-5D score and gender. Blinding of participants and outcome assessors is not
attempted.
Discussion: This is one of the largest trials of its kind. In the United Kingdom alone, 29,000 operations for haemorrhoidal
disease are done annually. The trial is therefore designed to give robust evidence on which clinicians and health
service managers can base management decisions and, more importantly, patients can make informed choices.
Trial registration: Current Controlled Trials ISRCTN80061723 (assigned 8 March 2010
Prototype Testing Results of Charged Particle Detectors and Critical Subsystems for the ESRA Mission to GTO
The Experiment for Space Radiation Analysis (ESRA) is the latest of a series of Demonstration and Validation (DemVal) missions built by the Los Alamos National Laboratory, with the focus on testing a new generation of plasma and energetic paritcle sensors along with critical subsystems. The primary motivation for the ESRA payloads is to minimize size, weight, power, and cost while still providing necessary mission data. These new instruments will be demonstrated by ESRA through ground-based testing and on-orbit operations to increase their technology readiness level such that they can support the evolution of technology and mission objectives. This project will leverage a commercial off-the-shelf CubeSat avionics bus and commercial satellite ground networks to reduce the cost and timeline associated with traditional DemVal missions. The system will launch as a ride share with the DoD Space Test Program to be inserted in Geosynchronous Transfer Orbit (GTO) and allow observations of the Earth\u27s radiation belts. The ESRA CubeSat consists of two science payloads and several subsystems: the Wide field-of-view Plasma Spectrometer, the Energetic Charged Particle telescope, high voltage power supply, payload processor, flight software architecture, and distributed processor module. The ESRA CubeSat will provide measurements of the plasma and energetic charged particle populations in the GTO environment for ions ranging from ~100 eV to ~1000 MeV and electrons with energy ranging from 100 keV to 20 MeV. ESRA will utilize a commercial 12U bus and demonstrate a low-cost, rapidly deployable spaceflight platform with sufficient SWAP to enable efficient measurements of the charged particle populations in the dynamic radiation belts
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