falciparum malaria revisiting: Topics by WorldWideScience.org

A prospective analysis of the Ab response to Plasmodium falciparum before and after a malaria season by protein microarray

BackgroundPregnant women are more susceptible to severe Plasmodium falciparum malaria, which can lead to poor maternal and fetal outcomes. Few data exist on the...Full Text Available

Phylogenomic analyses of malaria parasites and evolution of their exported proteins

Abs are central to malaria immunity, which is only acquired after years of exposure to Plasmodium falciparum (Pf). Despite the enormous worldwide burden of malaria,...Full Text Available

2010-04-13

Efficacy of drug prophylaxis.

BackgroundPlasmodium falciparum is the most malignant agent of human malaria. It belongs to the taxon Laverania, which includes other ape-infecting Plasmodium...Full Text Available

Contrasting Population Structures of the Genes Encoding Ten Leading Vaccine-Candidate Antigens of the Human Malaria Parasite, Plasmodium falciparum

With the spread of chloroquine resistant Plasmodium falciparum the control of malaria has become increasingly complex. In recent years, particular concern has arisen over how best to prevent malaria...Full Text Available

1989-01-01

The extensive diversity of Plasmodium falciparum antigens is a major obstacle to a broadly effective malaria vaccine but population genetics has rarely been used to guide vaccine design....Full Text Available

Molecular Mechanistic Insights into the Endothelial Receptor Mediated Cytoadherence of Plasmodium falciparum-Infected Erythrocytes

Naturally acquired immunity to Plasmodium falciparum malaria in malaria holoendemic areas is characterized by the gradual, age-related development of protection against high-density...Full Text Available

Accumulation of Plasmodium berghei-Infected Red Blood Cells in the Brain Is Crucial for the Development of Cerebral Malaria in Mice?

Cytoadherence or sequestration is essential for the pathogenesis of the most virulent human malaria species, Plasmodium falciparum (P. falciparum). Similar to leukocyte-endothelium...Full Text Available

The relationship between the Plasmodium falciparum parasite ratio in childhood and climate estimates of malaria transmission in Kenya

Cerebral malaria is the most severe complication of human infection with Plasmodium falciparum. It was shown that Plasmodium berghei ANKA-induced cerebral malaria was...Full Text Available

2010-09-01

The Dynamics of Naturally Acquired Immune Responses to Plasmodium falciparum Sexual Stage Antigens Pfs230 & Pfs48/45 in a Low Endemic Area in Tanzania

BackgroundPlasmodium falciparum morbid and fatal risks are considerably higher in areas supporting parasite prevalence ≥25%, when compared with low transmission...Full Text Available

Population genetic analysis of large sequence polymorphisms in Plasmodium falciparum blood-stage antigens

BackgroundNaturally acquired immune responses against sexual stages of P. falciparum can reduce the transmission of malaria from humans to mosquitoes. These antigens...Full Text Available

Diagnosis of Plasmodium falciparum infection using a solid-phase radioimmunoassay for the detection of malaria antigens

Plasmodium falciparum, the causative agent of human malaria, invades host erythrocytes using several proteins on the surface of the invasive merozoite, which have been proposed...Full Text Available

2010-03-01

Common variation in the ABO glycosyltransferase is associated with susceptibility to severe Plasmodium falciparum malaria

A serodiagnostic test has been developed for the detection of Plasmodium falciparum in infected blood. Using parasite antigens and infected red blood cells from in vitro...Full Text Available

1980-01-01

Blood Group A Antigen Is a Coreceptor in Plasmodium falciparum Rosetting

There is growing epidemiological and molecular evidence that ABO blood group affects host susceptibility to severe Plasmodium falciparum infection. The high frequency of common...Full Text Available

2008-02-15

Efficacy and safety of a fixed-dose oral combination of pyronaridine-artesunate compared with artemether-lumefantrine in children and adults with uncomplicated Plasmodium falciparum malaria: a randomised non-inferiority trial.

The malaria parasite Plasmodium falciparum utilizes molecules present on the surface of uninfected red blood cells (RBC) for rosette formation, and a dependency on ABO antigens has...Full Text Available

2000-05-01

Antibodies from malaria-exposed pregnant women recognize trypsin resistant epitopes on the surface of Plasmodium falciparum-infected erythrocytes selected for adhesion to chondroitin sulphate A

PMID:20417857

2010-04-24

DEFF Research Database (Denmark)

Udgivelsesdato: 2004-Sep-6

2004-01-01

Evaluation of the OptiMAL Test for Rapid Diagnosis of Plasmodium vivax and Plasmodium falciparum Malaria

Diagnostic comparison of malaria infection in peripheral blood, placental blood and placental biopsies in Cameroonian parturient women

The development of rapid and specific diagnostic tests to identify individuals infected with malaria is of paramount importance in efforts to control the severe public health impact of this disease....Full Text Available

1998-01-01

ABO blood group phenotypes influence parity specific immunity to Plasmodium falciparum malaria in Malawian women

BackgroundIn sub-Saharan Africa, Plasmodium falciparum malaria in pregnancy presents an enormous diagnostic challenge. The epidemiological and clinical relevance...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

BackgroundBlood group O has been significantly associated with increased placental malaria infection in primiparae and reduced risk of infection in multiparae in the Gambia, an area...Full Text Available

Summary Background There is a need for new artemisinin-based combination therapies that are convenient, effective, and safe. We compared the efficacy and safety of pyronaridine-artesunate with that of artemether-lumefantrine for treatment of uncomplicated P falciparum malaria. Methods This phase 3, parallel-group, double-blind, randomised, non-inferiority trial was undertaken in seven sites in Africa and three sites in southeast Asia. In a double-dummy design, patients aged 3-60 years with uncomplicated P falciparum malaria were randomly assigned in a 2:1 ratio to receive pyronaridine-artesunate once a day or artemether-lumefantrine twice a day, orally for 3 days, plus respective placebo. Randomisation was done by computer-generated randomisation sequence in blocks of nine by study centre....

2010-01-01

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Multiplicity of Plasmodium falciparum infection in asymptomatic children in Senegal: relation to transmission, age and erythrocyte variants

Measuring the efficacy of anti-malarial drugs in vivo: quantitative PCR measurement of parasite clearance

BackgroundIndividuals living in malaria endemic areas generally harbour multiple parasite strains. Multiplicity of infection (MOI) can be an indicator of immune status. However,...Full Text Available

Efficacy of sulphadoxine-pyrimethamine with or without artesunate for the treatment of uncomplicated Plasmodium falciparum malaria in southern Mozambique: a randomized controlled trial

BackgroundArtemisinin-based combination therapy, currently considered the therapy of choice for uncomplicated Plasmodium falciparum malaria in endemic countries,...Full Text Available

Deletion of the Plasmodium falciparum Merozoite Surface Protein 7 Gene Impairs Parasite Invasion of Erythrocytes?

BackgroundAn artemisinin-based combination therapy, artesunate (AS) plus sulphadoxine-pyrimethamine (SP), was compared to SP monotherapy to provide evidence of further treatment...Full Text Available

Comparative Transcriptional and Genomic Analysis of Plasmodium falciparum Field Isolates

Merozoite surface proteins have been implicated in the initial attachment to the host red blood cell membrane that begins the process of invasion, an important step in the life cycle of the malaria...Full Text Available

2008-12-01

An improved method for undertaking limiting dilution assays for in vitro cloning of Plasmodium falciparum parasites

Mechanisms for differential regulation of gene expression may underlie much of the phenotypic variation and adaptability of malaria parasites. Here we describe transcriptional variation among culture-adapted...Full Text Available

2009-10-01

Evaluation of the rapid diagnostic test SDFK40 (Pf-pLDH/pan-pLDH) for the diagnosis of malaria in a non-endemic setting

BackgroundObtaining single parasite clones is required for many techniques in malaria research. Cloning by limiting dilution using microscopy-based assessment for parasite growth...Full Text Available

An open randomized clinical trial in comparing two artesunate-based combination treatments on Plasmodium falciparum malaria in Nigerian children: artesunate/sulphamethoxypyrazine/pyrimethamine (fixed dose over 24 hours) versus artesunate/amodiaquine (fixed dose over 48 hours)

BackgroundThe present study evaluated the SD Bioline Malaria Ag 05FK40 (SDFK40), a three-band RDT detecting Plasmodium falciparum-specific parasite lactate dehydrogenase...Full Text Available

T Cell Responses to the RTS,S/AS01_E and RTS,S/AS02_D Malaria Candidate Vaccines Administered According to Different Schedules to Ghanaian Children

BackgroundSeveral studies have demonstrated the efficacy of artemisinin-combination therapy (ACT) across malaria zones of the world. Fixed dose ACT with shorter courses and fewer...Full Text Available

Anti-plasmodial activity and toxicity of extracts of plants used in traditional malaria therapy in Meru and Kilifi Districts of Kenya

BackgroundThe Plasmodium falciparum pre-erythrocytic stage candidate vaccine RTS,S is being developed for protection of young children against...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

The methanol and aqueous extracts of 10 plant species (Acacia nilotica, Azadirachta indica, Carissa edulis, Fagaropsis angolensis, Harrissonia abyssinica, Myrica salicifolia, Neoboutonia macrocalyx, Strychnos heningsii, Withania somnifera and Zanthoxylum usambarensis) used to treat malaria in Meru and Kilifi Districts, Kenya, were tested for brine shrimp lethality and in vitro anti-plasmodial activity against chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum (NF54 and ENT30). Of the plants tested, 40% of the methanol extracts were toxic to the brine shrimp (LD5050N. macrocalyx had the highest toxicity to brine shrimp nauplii (LD50 21.04+-1.8mg/ml). Methanol extracts of the rest of the plants exhibited mild or no brine shrimp toxicity (LD50>50mg/ml). The aqueo...

2006-01-01

Adult and child malaria mortality in India

THE BALDWIN EFFECT AND GENETIC ASSIMILATION: REVISITING TWO MECHANISMS OF EVOLUTIONARY CHANGE MEDIATED BY PHENOTYPIC ...

SummaryBackgroundMalaria, a non-fatal disease if detected promptly and treated properly, still causes many deaths in malaria-endemic countries with...Full Text Available

2010-11-20

Malaria vectors and transmission dynamics in coastal south-western Cameroon

... 1111/j.1558-5646.2007.00203.x THE BALDWIN EFFECT AND GENETIC ASSIMILATION: REVISITING TWO MECHANISMS OF ... to phenotypic plast...

CDC - Malaria - Malaria Worldwide - How Can Malaria Cases and...

BackgroundMalaria is a major public health problem in Cameroon. Unlike in the southern forested areas where the epidemiology of malaria has been better studied prior to the implementation...Full Text Available

A Rapid Murine Coma and Behavior Scale for Quantitative Assessment of Murine Cerebral Malaria

vaccination card during trial enrollment at the KEMRI/CDC site in Kenya. (Alan Rubin, KEMRI) KEMRI Clinical Officer Paul Ogai reviews a prospective participant's...

2011-09-24

Malaria transmission in two localities in north-western Argentina

BackgroundCerebral malaria (CM) is a neurological syndrome that includes coma and seizures following malaria parasite infection. The pathophysiology is not fully understood and cannot...Full Text Available

var gene transcription and PfEMP1 expression in the rosetting and cytoadhesive Plasmodium falciparum clone FCR3S1.2

BackgroundMalaria is one of the most important tropical diseases that affects people globally. The influence of environmental conditions in the patterns of temporal distribution...Full Text Available

Sensitivity of Plasmodium falciparum to chloroquine and sulfadoxine/pyrimethamine in Nigerian children.

BackgroundThe pathogenicity of Plasmodium falciparum is in part due to the ability of the parasitized red blood cell (pRBC) to adhere to intra-vascular host cell...Full Text Available

Sex and Death: The Effects of Innate Immune Factors on the Sexual Reproduction of Malaria Parasites

The in vivo sensitivity of Plasmodium falciparum to chloroquine and sulfadoxine/pyrimethamine was evaluated in children under 5 years of age in two areas of southern Nigeria in 1987. A modification...Full Text Available

1990-01-01

Relationship Between Exposure, Clinical Malaria, and Age in an Area of Changing Transmission Intensity

Malaria parasites must undergo a round of sexual reproduction in the blood meal of a mosquito vector to be transmitted between hosts. Developing a transmission-blocking intervention to prevent parasites...Full Text Available

2011-03-01

Prospects, achievements, challenges and opportunities for scaling-up malaria chemoprevention in pregnancy in Tanzania: the perspective of national level officers

The relationship between malaria transmission intensity and clinical disease is important for predicting the outcome of control measures that reduce transmission. Comparisons of hospital data...Full Text Available

2008-08-01

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Performance and usefulness of the Hexagon rapid diagnostic test in children with asymptomatic malaria living in the Mount Cameroon region

ObjectivesTo describe the prospects, achievements, challenges and opportunities for implementing intermittent preventive treatment for malaria in pregnancy (IPTp) in Tanzania in...Full Text Available

An Immune Basis for Malaria Protection by the Sickle Cell Trait

BackgroundRapid and correct diagnosis of malaria is considered an important strategy in the control of the disease. However, it remains to be determined how well these tests can...Full Text Available

A Research Agenda for Malaria Eradication: Drugs

BackgroundMalaria resistance by the sickle cell trait (genotype HbAS) has served as the prime example of genetic selection for over half a century. Nevertheless, the mechanism...Full Text Available

2005-05-01

Genetic Applications in Avian Conservation

Antimalarial drugs will be essential tools at all stages of malaria elimination along the path towards eradication, including the early control or “attack” phase to drive down transmission...Full Text Available

2011-01-01

Intermittent preventive treatment of malaria during pregnancy: a qualitative study of knowledge, attitudes and practices of district health managers, antenatal care staff and pregnant women in Korogwe District, North-Eastern Tanzania

... structure along an elevational gradient in Hawaiian honeycreepers reveals contrasting evolutionary responses to avian malaria. BMC Evolutionary Biology 8: ... ...

Ribose metabolism and nucleic acid synthesis in normal and glucose-6-phosphate dehydrogenase-deficient human erythrocytes infected with Plasmodium falciparum.

BackgroundIntermittent preventive treatment of malaria during pregnancy (IPTp) is a key intervention in the national strategy for malaria control in Tanzania. SP, the current drug...Full Text Available

Intelligence Oversight Revisited: Does CONUS Base Security ...

The metabolism of pentose-phosphate was investigated in Plasmodium falciparum-infected normal and glucose-6-phosphate dehydrogenase (G6PD)-deficient human red blood cells in vitro. 5'-Phosphoribosyl-1-pyrophosphate...Full Text Available

1986-04-01

Deja vu: The Unified Command Plan of the Future Revisited

... Department of Defense (DoD) Directive 5240.1-R. Procedures Governing the Activities of DoD Intelligence Components that Affect United States ...

2001-04-01

Cognitive and Functional Decline in Huntington's Disease: Dementia Criteria Revisited

... WHS- Washington Headquarters Service. ... The standing Joint Task Force concept should be used more to provide warfighter forces and ...

2011-05-19

Decreased semen quality in a male infected with malaria.

The importance of designating criteria for diagnosing dementia lies in its implications for clinical treatment, research, caregiving, and decision-making. Dementia diagnosis in Huntington's...Full Text Available

2010-07-15

Contributions of Anopheles larval control to malaria suppression in tropical Africa: review of achievements and potential

A 33-year-old male of proven fertility suffered six attacks of malaria while resident in an African country. For this he received anti-malarial drugs. Semen analysis performed after the fourth attack, and repeated during the following 2 years after his return to Israel, revealed severe oligozoospermia, necrozoospermia and occasionally even azoospermia. Immunological examination of the patient revealed an inverse ratio of T-cell subsets and mast cell degranulation in response to palludrin. Twenty-five months after the last attack of malaria a significant improvement was found in semen quality and there was an increase in the ratio of T-helper to T-suppressor cytotoxic cells. These observations indicate that although malaria and its treatment may affect spermatogenesis, recovery may be expected eventually. PMID:3500921

1987-10-01

British Library Electronic Table of Contents (United Kingdom)

Abstract. Malaria vector control targeting the larval stages of mosquitoes was applied successfully against many species of Anopheles (Diptera: Culicidae) in malarious countries until the mid-20th Century. Since the introduction of DDT in the 1940s and the associated development of indoor residual spraying (IRS), which usually has a more powerful impact than larval control on vectorial capacity, the focus of malaria prevention programmes has shifted to the control of adult vectors. In the Afrotropical Region, where malaria is transmitted mainly by Anopheles funestus Giles and members of the Anopheles gambiae Giles complex, gaps in information on larval ecology and the ability of An. gambiae sensu lato to exploit a wide variety of larval habitats have discouraged efforts to develop and impl...

2007-01-01

Chemical and anti malaria study In vivo and In vitro of extracts of among barks of Maytenus rigid (Celastraceae)

Building the Perfect Parasite: Cell Division in Apicomplexa

Portuguese 2004 [1 p.] Brazil Estevam, Charles dos S. Andrade Neto,

Statistical properties of nucleotide clusters in DNA sequences*

Apicomplexans are pathogens responsible for malaria, toxoplasmosis, and crytposporidiosis in humans, and a wide range of livestock diseases. These unicellular eukaryotes are stealthy invaders, sheltering...Full Text Available

2007-06-01

Impact of Plasmodium falciparum infection on the frequency of moderate to severe anaemia in children below 10 years of age in Gabon

Using the complete genome of Plasmodium falciparum 3D7 which has 14 chromosomes as an example, we have examined the distribution functions for the amount of C or G and A or T consecutively...Full Text Available

2005-05-01

Socio-economic differences and health seeking behaviour for the diagnosis and treatment of malaria: a case study of four local government areas operating the Bamako initiative programme in south-east Nigeria

BackgroundImproving the understanding of childhood malarial anaemia may help in the design of appropriate management strategies.MethodsA...Full Text Available

A Randomized Trial Assessing the Safety and Immunogenicity of AS01 and AS02 Adjuvanted RTS,S Malaria Vaccine Candidates in Children in Gabon

BackgroundMalaria is one of the leading causes of mortality and morbidity in Nigeria. It is not known how user fees introduced under the Bamako Initiative (BI) system affect healthcare...Full Text Available

Two-site exchange revisited: a new method for extracting exchange parameters in biological systems.

BackgroundThe malaria vaccine candidate antigen RTS,S includes parts of the pre-erythrocytic stage circumsporozoite protein fused to the Hepatitis B surface antigen. Two Adjuvant...Full Text Available

Luetic aortopathy: Revisited

A new analysis is presented which links real volume fractions, relaxation rates, and intracompartmental exchange rates directly with apparent volume fractions and relaxation rates obtained from biexponential...Full Text Available

1989-02-01

Using schoolchildren's reports of bed net use monitored by schoolteachers as a proxy of community coverage in malaria endemic areas of Uganda:

We report a case of 38-year-old male, who presented with a large pulsatile swelling on the left side of the anterior chest wall of 4 months’ duration with a gradual increase in size. He gave...Full Text Available

2010-07-01

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British Library Electronic Table of Contents (United Kingdom)

Summary Objective Community-based information on the delivery and use of health interventions is important to monitor the effectiveness of the Roll Back Malaria programme. However, community surveys to determine coverage for insecticide-treated bed nets are time-consuming and costly. We wanted to assess whether schoolchildren's reports of household ownership of a bed net and coverage among high-risk groups monitored by schoolteachers through a questionnaire could be used as a proxy of household ownership of bed net and coverage at community level, for routine monitoring of malaria control programmes. Method 3602 schoolchildren in 39 randomly selected schools and 2798 heads of households in 39 villages were interviewed about their use of either insecticide-treated or untreated bed nets. Res...

2007-01-01

Studies on the breeding habitats of the vector mosquito Anopheles baimai and its relationship to malaria incidence in Northeastern region of India

British Library Electronic Table of Contents (United Kingdom)

Entomological survey was conducted to know the breeding habitat preference of the forest breeder malaria vector Anopheles baimaii, known earlier as An. dirus species D in the northeastern region of India. Breeding potential of the vector in forest areas was found to be high in water stored in jungle pool (69.84%) followed by elephant footprints with clear water (39.13%) and with turbid water (26.19%), whereas in forest fringe areas, the vector breeding was more prominent in elephant footprints: 65.11% in clear water and 62.5% in turbid water. Although other habitats had shown only low breeding of the vector, all types of habitats were positively correlated with malaria occurrence. Cattle hoof marks (r?=?0.998) and elephant footprint (turbid; r?=?0.999) explained nearly the same amount of v...

2010-01-01

Revisiting light neutralino scenarios in the MSSM

Satellite imagery in the study and forecast of malaria

We revisit the case of a light neutralino LSP in the framework of the MSSM. We consider a model with eleven free parameters. We show that all scenarios where the annihilation of light neutralinos rely mainly on the exchange of a light pseudoscalar are excluded by direct detection searches and by Fermi measurements of the gamma-flux from dwarf spheroidal galaxies. On the other hand, we find scenarios with light sleptons that satisfy all collider and astroparticle physics constraints. In this case, the lower limit on the LSP mass is 12.6 GeV. We discuss how the parameter space of the model will be further probed by new physics searches at the LHC.

2011-01-01

Reduction of anti-malarial consumption after rapid diagnostic tests implementation in Dar es Salaam: a before-after and cluster randomized controlled study

More than 30 years ago, human beings looked back from the Moon to see the magnificent spectacle of Earth-rise. The technology that put us into space has since been used to assess the damage...Full Text Available

2002-02-07

Reduced Efficacy of Insecticide-treated Nets and Indoor Residual Spraying for Malaria Control in Pyrethroid Resistance Area, Benin

BackgroundPresumptive treatment of all febrile patients with anti-malarials leads to massive over-treatment. The aim was to assess the effect of implementing malaria rapid diagnostic...Full Text Available

Processing and microfiltration of mosquitoes for malaria antigen detection in a rapid dot immunobinding assay.

The pyrethroid knockdown resistance gene (kdr) has become widespread in Anopheles gambiae in West Africa. A trial to test the continuing efficacy of insecticide-treated...Full Text Available

2007-02-01

Prevalence of contraindications to mefloquine use among USA military personnel deployed to Afghanistan

Data on a technique for the detection of antigen from arthropod vectors in a dot immunobinding assay are presented. In this system, antigen present in the vector was first solubilized in sodium dodecyl...Full Text Available

1990-08-01

Measuring Urbanization Pattern and Extent for Malaria Research: A Review of Remote Sensing Approaches

BackgroundMefloquine has historically been considered safe and well-tolerated for long-term malaria chemoprophylaxis, but its prescribing requires careful attention to rule out contraindications...Full Text Available

Malaria knowledge and agricultural practices that promote mosquito breeding in two rural farming communities in Oyo State, Nigeria

Within the next 30 years, the proportion of urban dwellers will rise from under half to two thirds of the world’s population. Such a shift will entail massive public health consequences,...Full Text Available

2004-09-01

Larvicidal effects of a neem (Azadirachta indica) oil formulation on the malaria vector Anopheles gambiae

BackgroundAgricultural practices such as the use of irrigation during rice cultivation, the use of ponds for fish farming and the storage of water in tanks for livestock provide...Full Text Available

Landscape determinants and remote sensing of anopheline mosquito larval habitats in the western Kenya highlands

BackgroundLarviciding is a key strategy used in many vector control programmes around the world. Costs could be reduced if larvicides could be manufactured locally. The potential...Full Text Available

Impact of repeated four-monthly anthelmintic treatment on Plasmodium infection in preschool children: a double-blind placebo-controlled randomized trial

BackgroundIn the past two decades the east African highlands have experienced several major malaria epidemics. Currently there is a renewed interest in exploring the possibility...Full Text Available

Field application of a colorimetric method of assaying chloroquine and desethylchloroquine in urine

BackgroundHelminth infections can alter susceptibility to malaria. Studies need to determine whether or not deworming programs can impact on Plasmodium infections...Full Text Available

Effect of discriminative plant-sugar feeding on the survival and fecundity of Anopheles gambiae

In a study in western Kenya of malaria-infected adult women who had been treated with chloroquine, we compared the level of chloroquine and its principal metabolite, desethylchloroquine, in urine,...Full Text Available

1988-01-01

ABO blood group and the risk of placental malaria in sub-Saharan Africa

BackgroundA previous study showed for Anopheles gambiae s.s. a gradation of feeding preference on common plant species growing in a malaria holoendemic area in western...Full Text Available

Adult abundance, biting behavior and parity of Anopheles aquasalis, Curry 1932 in two malarious areas of Sucre State, Venezuela

BackgroundIn malarious areas of the world, a higher proportion of the population has blood group O than in non-malarious areas. This is probably due to a survival advantage conferred...Full Text Available

Scientific Electronic Library Online (English)

Abstract in english The principal vector of malaria in eastern Venezuela, Anopheles aquasalis, is exophagic and exophilic. Control using indoor insecticide house sprays has failed to lower the number of malaria cases. Therefore, studies were initiated in two villages of the eastern coastal state of Sucre to better understand this vector's biology and develop a more integrated control program. An. aquasalis was found to have a crepuscular biting behavior with a major peak at dusk and a minor (more) peak at dawn. Mosquitos were collected more outdoors than indoors. Forty-seven percent of the biting took place before people went to bed (22:30 hr) and 69% of the mosquitos biting during this time period bite outdoors. Outdoor biting could be the reason why indoor spraying alone did not lower malaria cases. Seasonal abundance was greater in the rainy season compared to the dry season. Seasonal parous rates were high (78.3%-100%) ...

1993-09-01

Revisited the mathematical derivation wall thickness measurement of pipe for radiography

Vibrational spectra of vinylarsine: A joint IR experimental and anharmonic theoretical study

Wall thickness measurement of pipe is very important of the structural integrity of the industrial plant. However, the radiography method has an advantage because the ability of penetrating the insulated pipe. This will have economic benefit for industry. Moreover, the era of digital radiography has more advantages because the speed of radiographic work, less exposure time and no chemical used for film development. Either the conventional radiography or digital radiology, the wall thickness measurement is using the tangential radiography technique (TRT). In case, of a large diameter, pipe (more than inches) the determination maximum penetration wall thickness must be taken into the consideration. This paper is revisited the mathematical derivation of the determination of wall thickness measurement based on tangential radiography technique (TRT). The mathematical approach used in this derivation is the Pythagoras theorem and geometrical principles. In order to ...

2007-07-01

British Library Electronic Table of Contents (United Kingdom)

A joint experimental and theoretical analyses based on the grounds of DFT anharmonic potential and the use of a variational method allow us to revisit and assign the gas phase spectra of vinylarsine in the mid-IR area until 6300cm-1. Several weak and very weak bands corresponding to overtones and combinations are newly observed and assigned in complement to the fundamental bands.

2009-01-01

Tachyons revisited

Super-heavy Quarkonia and the Gluon Condensate

An apparently significant result in an experiment to search for tachyons in the interval of time immediately preceding in the arrival of air showers of energy approximately 10"1"5 eV is considered. Several similar experiments have been completed, all of which have yielded null results. The original data of the foregoing reference have been re-examined and it is shown that an artifact of the apparatus was contributing to the original apparently significant results. (orig./BJ).

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Revisiting new variant famine: the case of Swaziland

The early idea that a non-perturbative gluon condensate affects the spectrum of heavy quarks is revisited in the light of modern simulation techniques. We evaluate the low lying spectrum of bound states of two heavy quarks for large hypothetical quark mass, m_Q > m_b, using non-relativistic QCD and compare with other models to test the consistency.

1999-01-01

British Library Electronic Table of Contents (United Kingdom)

The ?new variant famine? hypothesis posits links between HIV/AIDS and new patterns of impoverishment, food insecurity and hunger, in southern and eastern Africa. This paper explores the relevance of the NVF hypothesis to understanding Swaziland?s recurrent food crises and high HIV prevalence. Evidence exists that all four markers of NVF are present in Swaziland. The national government and the international community will have to contend with this phenomenon in future planning for the wellbeing of Swazi citizens.

2009-01-01

Randomized controlled trials of the efficacy of lung cancer screening by sputum cytology revisited: a combined mortality analysis from the Johns Hopkins Lung Project and the Memorial Sloan-Kettering Lung Study

Energy flux operator, current conservation and the formal Fourier's law

BackgroundTwo randomized controlled trials of lung cancer screening initiated in the 1970's, the Johns Hopkins Lung Project and the Memorial Sloan-Kettering Lung...Full Text Available

2009-11-01

Comment on 'Magnetic braking revisited: activities for the undergraduate laboratory'

By revisiting previous definitions, we show that one can define an energy current operator that satisfies the continuity equation for a general Hamiltonian in one dimension. This expression is useful for studying electronic, phononic and photonic energy flow in linear systems and in hybrid structures. The definition allows us to deduce the necessary conditions that result in current conservation for general-statistics systems. The discrete form of the Fourier's law of heat conduction naturally emerges in the present definition.

2009-01-16

Malaria and other vector-borne infection surveillance in the U.S. Department of Defense Armed Forces Health Surveillance Center-Global Emerging Infections Surveillance program: review of 2009 accomplishments

Here, we consider a recent paper concerned with magnetic braking by induced currents (Ireson and Twidle 2008 Eur. J. Phys. 29 745-51). Our objective is to elucidate why measurement of speed in which a magnet is dropped through a non-ferromagnetic conductive tube depends on its geometry in a non-monotonic way, which was not clearly explained by the authors. (letters and comments)

2009-03-01

Identification of a novel class of insect glutathione S-transferases involved in resistance to DDT in the malaria vector Anopheles gambiae.

Vector-borne infections (VBI) are defined as infectious diseases transmitted by the bite or mechanical transfer of arthropod vectors. They constitute a significant proportion of the global infectious...Full Text Available

Control of pyrethroid and DDT-resistant Anopheles gambiae by application of indoor residual spraying or mosquito nets treated with a long-lasting organophosphate insecticide, chlorpyrifos-methyl

The sequence and cytological location of five Anopheles gambiae glutathione S-transferase (GST) genes are described. Three of these genes, aggst1-8, aggst1-9 and aggst1-10, belong to the insect class...Full Text Available

2001-10-15

A qualitative study of the feasibility and community perception on the effectiveness of artemether-lumefantrine use in the context of home management of malaria in south-west Nigeria

BackgroundScaling up of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) with support from the Global Fund and President's Malaria Initiative is providing...Full Text Available

The quantum Zeno paradox revisited: the time evolution for a two-level system interacting with a reservoir

BackgroundIn Nigeria ACT use at the community level has not been evaluated and the use of antimalarial drugs (commonly chloroquine (CQ)) at home has been shown to be largely incorrect....Full Text Available

Firewall Configuration Errors Revisited

We revisited the quantum Zeno paradox, which claims that a generic quantum system prepared in a state which is not an eigenstate of the Hamiltonian operator and is continuously observed never decays. Since any perfectly isolated quantum system always interact with a vacuum field, we analyze the possibility of using this fact to solve the above mentioned conceptual problem. Therefore we discuss a two-level system or qubit-Bose field interaction Hamiltonians. We consider the quantum dynamics of this two-level system, prepared in the excited state interacting with a Bose field prepared in the Poincare invariant vacuum state. Using a first-order approximation in time-dependent perturbation theory, we evaluate the probability of spontaneous decay of the two-level system driven by the vacuum field. This probability is evaluated for a finite time interval. Using the standard argument to obtain the quantum Zeno paradox, we consider N measurements where N {yields} ...

2006-12-15

IDEAS: The Science, Sociology and Economics of Food Production and Access to Food, Springer

The first quantitative evaluation of the quality of corporate firewall configurations appeared in 2004, based on Check Point FireWall-1 rule-sets. In general that survey indicated that corporate firewalls were often enforcing poorly written rule-sets, containing many mistakes. The goal of this work is to revisit the first survey. The current study is much larger. Moreover, for the first time, the study includes configurations from two major vendors. The study also introduce a novel "Firewall Complexity" (FC) measure, that applies to both types of firewalls. The findings of the current study indeed validate the 2004 study's main observations: firewalls are (still) poorly configured, and a rule-set's complexity is (still) positively correlated with the number of detected risk items. Thus we can conclude that, for well-configured firewalls, ``small is (still) beautiful''. However, unlike the 2004 study, we see no significant indication that later software versions ...

2009-01-01

Wastenet

... (restricted)] 251-260 Revisiting new variant famine: the case of Swaziland by Scott Naysmith & Alex Waal & Alan Whiteside [Downloadable! (restricted)] 261-269 Food prices and the HIV response: findings from rapid regional assessments in eastern and southern Africa in 2008[InlineMediaObject not available: see fulltext.][InlineMediaObject not available: see fulltext.] by Stuart Gillespie & Paul Jere & John Msuya & Scott Drimie [Downloadable! (restricted)] 271-289 Declining global per capita agricultural production and warming oceans ...

Antiprotozoal and cytotoxic activities in vitro of Colombian Annonaceae

British Library Electronic Table of Contents (United Kingdom)

Ethnobotanical and chemotaxonomical studies for antiparasitic activity of Colombian Annonaceae were carried out. In vitro antiprotozoal activity of 36 extracts obtained from six different species was determined against promastigotes of three Leishmania species, epimastigotes of Trypanosoma cruzi and both chloroquine sensitive (F32) and resistant (W2) Plasmodium falciparum. Cytotoxic activity was evaluated in U-937 cells. Active extracts were selected according their selectivity index (SI). Extracts from Annona muricata, Rollinia exsucca, Rollinia pittieri and Xylopia aromatica were active against Leishmania spp. and Trypanosoma cruzi showing IC50 values lower than 25mg/ml. Hexane extract from Rollinia pittieri leaves was the most selective against Trypanosoma cruzi and Leishmania spp. (IS=...

2007-01-01

Neuroinflammation and brain infections: Historical context and current perspectives

British Library Electronic Table of Contents (United Kingdom)

An overview of current concepts on neuroinflammation and on the dialogue between neurons and non-neuronal cells in three important infections of the central nervous systems (rabies, cerebral malaria, and human African trypanosomiasis or sleeping sickness) is here presented. Large numbers of cases affected by these diseases are currently reported. In the context of an issue dedicated to Camillo Golgi, historical notes on seminal discoveries on these diseases are also presented. Neuroinflammation is currently closely associated with pathogenetic mechanisms of chronic neurodegenerative diseases. Neuroinflammatory signaling in brain infections is instead relatively neglected in the neuroscience community, despite the fact that the above infections provide paradigmatic examples of alterations o...

2011-01-01

Transformed Governance and the Education for All-Fast Track Initiative. Policy Brief 2010-02

The two-dimensional derivative-coupling model revisited

The Education for All-Fast Track Initiative (FTI) grew out of the "New Focus on Education for All" communique of the G-8 when Canada hosted the summit in 2002 at Kananaskis. As Canada prepares again to host the G-8, and Korea assumes leadership of the newly-empowered G-20, it is a valuable moment to revisit and re-think the current global education architecture. By adopting some of the recommendations from the recent independent evaluation of the FTI and borrowing some lessons from global partnerships in other sectors, the FTI could set a new course toward the achievement of universal basic education. The FTI should broaden and strengthen the role of diverse stakeholders from developing countries and civil society in its governance structure in order to fully harness the energies of these stakeholders in resource mobilization and effective implementation. (Contains 9 endnotes.)

2010-05-01

The evaporation pan technique revisited: Old theory and a new application for time-weighted synoptic tracing of the isotopic composition of atmospheric vapour

Using the operator approach we reexamine the two-dimensional model describing a massive Fermi field interacting via derivative couplings with two massless Bose fields, one scalar and the other pseudoscalar. Performing a canonical transformation on the Bose field algebra, the Fermi field operator is written in terms of the Mandelstam soliton operator and the derivative-coupling (DC) model is mapped into the massive Thirring model with two vector-current-scalar-derivative interactions (Schroer-Thirring model). The DC model with massless fermions can be mapped into the massless Rothe-Stamatescu model with a Thirring interaction (massless Rothe-Stamatescu-Thirring model). Within the present approach the weak equivalence between the fermionic sector of the DC model and the massive Thirring model is exhibited compactly.

2007-05-11

The environmental Kuznets curve hypothesis for water pollution: Do regions matter?

Reliable and consistent characterization of the stable isotope composition of atmospheric water vapour and its temporal variability are important prerequisites to the wider application of isotope mass balance methods in atmospheric and water balance studies. A new approach is proposed which utilizes standard class-A evaporation pans, which have sufficient volume to buffer short-term transient variations in atmospheric conditions, justifying the assumption of constant kinetic isotopic fractionation effects in concert with precisely measured temperature and relative humidity to derive vapour isotopic composition. The results of the studies suggest that isotopic sampling of existing, conventionally operated class-A evaporation pans could offer a straightforward and cost-effective solution to the problem of documenting the shifting isotopic distribution in atmospheric moisture

1999-12-01

The environmental Kuznets curve hypothesis for water pollution: Do regions matter?

This study revisits the environmental Kuznets curve (EKC) hypothesis for water pollution by using a recent dynamic technique, which is the generalized method of moments (GMM) approach, for a board sample of 97 countries during the period 1980-2001. On a global scale, as we cannot obtain the EKC relationship between real income and biological oxygen demand (BOD) emissions, this paper further classifies these countries into four regional groups - Africa, Asia and Oceania, America, and Europe - to explore whether the different regions have different ECK relationships. The empirical results show evidence of the inverted U-shaped EKC relationships' existence in America and Europe, but not in Africa and Asia and Oceania. Thus, the regional difference of EKC for water pollution is supported. Furthermore, the estimated turning points are, approximately, US$13,956 and US$38,221 for America and Europe, respectively.

2010-01-15

The environmental Kuznets curve hypothesis for water pollution. Do regions matter?

2010-01-01

100

The Aldous-Shields model revisited (with application to cellular ageing)

2010-01-15

1 2 3 4 5 6 7

101

Testing an agent-based model of bacterial cell motility: How nutrient concentration affects speed distribution

In Aldous and Shields (1988), a model for a rooted, growing random binary tree was presented. For some c>0, an external vertex splits at rate c^(-i) (and becomes internal) if its distance from the root (depth) is i. For c>1, we reanalyse the tree profile, i.e. the numbers of external vertices in depth i=1,2,.... Our main result are concrete formulas for the expectation and covariance-structure of the profile. In addition, we present the application of the model to cellular ageing. Here, we assume that nodes in depth h+1 are senescent, i.e. do not split. We obtain a limit result for the proportion of non-senescent vertices for large h.

2010-01-01

102

British Library Electronic Table of Contents (United Kingdom)

We revisit a recently proposed agent-based model of active biological motion and compare its predictions with own experimental findings for the speed distribution of bacterial cells, Salmonella typhimurium. Agents move according to a stochastic dynamics and use energy stored in an internal depot for metabolism and active motion. We discuss different assumptions of how the conversion from internal to kinetic energy d(v) may depend on the actual speed, to conclude that d 2 v ? with either ? = 2 or 1 ? < 2 are promising hypotheses. To test these, we compare the model?s prediction with the speed distribution of bacteria which were obtained in media of different nutrient concentration and at different times. We find that both hypotheses are in line with the experimental observations, with ? bet...

2011-01-01

103

Tachyons revisited - comments on a search for faster-than-light particles

Spectroscopy of gadolinium gallium garnet crystals doped with Y b3+ revisited

An apparently significant result in an experiment to search for tachyons in the interval of time immediately preceding the arrival of air showers of energy greater than 10"1"5 eV has been reported by Clay and Crouch (Clay, R.W. and Crouch, P.C., 1974, Nature, vol.248,28-30). Several similar experiments have been completed, all of which have yielded null results. The original data of Clay and Crouch have been re-examined and it is shown that an artifact of the apparatus was contributing to the original, apparently significant, result. An upper limit estimate shows that the number of tachyons is less than the number of hadrons of energy greater than 100 GeV in showers of average size N = 6 x 10"5 particles. (author).

104

Revisiting an old hypothesis of human thermal perception: alliesthesia

The optical spectroscopy measurements of gadolinium gallium garnet (GGG) crystals doped with Yb show evidence of the presence of non-equivalent optical centers with very similar radiative decay rates. The energy level schemes of those centers have been determined on the basis of optical absorption, luminescence and Raman experiments. Crystal field fitting resulted in two sets of slightly different crystal field parameters for two non-equivalent Yb centers. Both sets of parameters describe perfectly the experimentally detected Y b3+ energy levels. Correlation between systematic trends in the experimental energy level schemes and crystal field parameters is discussed.

2010-06-30

105

British Library Electronic Table of Contents (United Kingdom)

Many new technologies and approaches to the provision of comfort inside buildings such as displacement ventilation, mixed-mode strategies, personally controllable (task-ambient) designs, chilled beams as well as some old but recently fashionable ones such as natural ventilation are prompting a rethink of the accepted comfort wisdom. How can a single combination of thermal environmental parameters be deemed unacceptable in a conventional heating ventilation and air-conditioning setting, and yet be regarded as acceptable, or even pleasant, in a naturally ventilated or mixed-mode setting? Why do current comfort standards prescribe static and isothermal conditions for comfort in one building, and dynamic and spatially variable indoor climates for comfort in another? The phenomenon of alliesthe...

2011-01-01

106

Particle Flow at CMS and the ILC

On the sensitivity of coastal quasigeostrophic edge wave interaction to bottom boundary characteristics: possible implications for eddy parameterizations

This thesis describes hadron reconstruction at the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN, Geneva. The focus is on the particle flow reconstruction of these objects. This thesis revisits the subject of the CMS calorimeters' non-linear response to hadrons. Data from testbeam experiments conducted in 2006 & 2007 is compared with simulations and substantial differences are found. A particle flow calibration to correct the energy response of the testbeam data is evaluated. The reconstructed jet response is found to change by ~ 5% when a data-driven calibration is used in place of the calibration derived from simulation. Collision data taken at the early stage of CMS' commissioning is also presented. The hadron response in data is determined to be compatible with testbeam results presented in this thesis. This thesis also details the use of neural networks to improve the energy measurement of hadrons at CMS. The networks ...

2010-01-01

107

On Essential Incompleteness of Hertz's Experiments on Propagation of Electromagnetic Interactions

The Eady problem of baroclinic instability as applicable to quasi-geostrophic oceanic flows with zero internal PV gradients is revisited by introducing a mild slope and Ekman pumping on the lower boundary. The solution behaviour is determined by the isopycnal slope relative to either the bottom slope or the ratio of Ekman depth to horizontal wavenumber. Attention is paid to the physical interpretation of the growing, decaying and stable disturbances, with emphasis on the intimate connection between the quasigeostrophic edge waves and Eady waves, and the role of the isopycnal slope for the stability properties as opposed to the bottom density gradient. The disturbance structure is found to be strongly influenced by the boundary conditions. For a sloping bottom boundary, the growth rate is enhanced for the most unstable waves if the isopycnals tilt in the same direction as the bottom, but in general non-standard boundary conditions tend to retard the growth of ...

2004-01-01

108

Linearization effect in multifractal analysis: Insights from Random Energy Model analysis

The historical background of the 19th century electromagnetic theory is revisited from the standpoint of the opposition between alternative approaches in respect to the problem of interactions. The 19th century electrodynamics became the battle-field of a paramount importance to test existing conceptions of interactions. Hertz's experiments were designed to bring a solid experimental evidence in favor of one of them. The modern scientific method applied to analyze Hertz's experimental approach as well as the analysis of his laboratory notes, dairy and private letters show that Hertz's "\\textit{crucial}" experiments cannot be considered as conclusive at many points as it is generally implied. We found that alternative Helmholtz's electrodynamics did not contradict any of Hertz's experimental observations of transverse components as Maxwell's theory predicted. Moreover, as we now know from recently published Hertz's dairy and private notes, his first experimental ...

2005-01-01

109

Is Gold Really Softer than Silver? HSAB Principle Revisited

The analysis of the linearization effect in multifractal analysis, and hence of the estimation of moments for multifractal processes, is revisited borrowing concepts from the statistical physics of disordered systems, notably from the analysis of the so-called Random Energy Model. Considering a standard multifractal process (compound Poisson motion), chosen as a simple representative example, we show: i) the existence of a critical order q* beyond which moments, though finite, cannot be estimated through empirical averages, irrespective of the sample size of the observation; ii) that multifractal exponents necessarily behave linearly in q, for q > q*. Tailoring the analysis conducted for the Random Energy Model to that of Compound Poisson motion, we provide explicative and quantitative predictions for the values of q* and for the slope controlling the linear behavior of the multifractal exponents. These quantities are shown to be related only to the definition ...

2010-01-01

110

GHG emissions, GDP growth and the Kyoto Protocol: A revisit of Environmental Kuznets Curve hypothesis

A detailed comparison of the softness of gold and silver has been reported in the light of hard soft acid base (HSAB) principle. Gold and silver nanoparticles in organic media (i.e., organosol) have been exploited individually to establish the principle. Sulfur and nitrogen were employed as soft and borderline donating atoms to examine the metal-ligand interactions. In this regard, thiols and amines have been considered as interacting ligands with sulfur and nitrogen donor atoms respectively. The stronger affinity of gold towards softer sulfur donor as compared to nitrogen and conversely a reasonable interaction of silver nanoparticles with both the atoms authenticate the softer nature of gold nanoparticle as compared to silver one.

2006-02-15

111

British Library Electronic Table of Contents (United Kingdom)

The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis.This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of "hot air" which is significant to the implementation of the Kyoto Protocol. In addition, through the ...

2008-01-01

112

Cosmic time dilation: The clock paradox revisited

Biochemical basis of circadian rhythms and diseases: With emphasis on post-traumatic stress disorder

The relativistic time dilation is reviewed in a cosmological context. We show that a clock or twin paradox does not arise if cosmic time is properly taken into account. The receding galaxy background provides a unique frame of reference, and the proper times of geodesic as well as accelerated observers can be linked to the universal cosmic time parameter. This suggests to compare the proper time differentials of the respective observers by determining their state of motion in the galaxy grid. In this way, each observer can figure out whether his proper time is dilated or contracted relative to any other. In particular one can come to unambiguous conclusions on the aging of uniformly moving observers, without reference to asymmetries in measurement procedures or accelerations they may have undergone.

2004-05-01

113

British Library Electronic Table of Contents (United Kingdom)

Circadian rhythms affect several processes in the body physiology. This commentary revisits the topic of `metabolic basis of diseases' with a view to shed light on how cellular energy requirements feed-forward to a sequential signaling of hormonal response, blood glucose metabolism, antioxidant activities, and pathophysiology. Attempt is made to explain how diseases that may not appear to be closely related, such as bone metabolism and vasculopathy, have an increase in oxidative damage as a common underlying biochemistry. Importantly, this article identifies oxidative damage as an outcome of sleep disturbance and hypothesize that sleep complaint is not merely one of many resulting symptoms of PTSD, but a core feature that arise from trauma and gives rise to the stress biochemistry, which i...

2011-01-01

114

A Hundred Years of Physics on Show

CERN Multimedia

The New Yorker Richard Feynman, well known to all physicists for his diagrams. Eleven vivid posters have recently been hung along the Theoretical Physics corridor on the first floor of Building 53. They tell the story of a century of physics, between 1900 and the end of the nineteen-nineties, the century that gave us atomic and quantum physics and the great breakthroughs that have rocked our understanding of the world and the universe. The posters are a gift from the American Physical Society to the CERN Library. As they were designed for high school and university book collections in the US, they necessarily have a somewhat American view of the history of science. But it is still instructive to revisit contemporary physics through its great figures, such as Marie Curie, Stephen Hawking, and Richard Feynman, not to mention Albert Einstein and many others. Why not take the time for a little trip down this particular stretch of Memory Lane?

2002-01-01

115

The H-test probability distribution revisited: Improved sensitivity

The BESS model revisited as a Higgsless Linear Moose @ the LHC

Aims: To provide a significantly improved probability distribution for the H-test for periodicity in X-ray and $\\gamma$-ray arrival times, which is already extensively used by the $\\gamma$-ray pulsar community. Also, to obtain an analytical probability distribution for stacked test statistics in the case of a search for pulsed emission from an ensemble of pulsars where the significance per pulsar is relatively low, making individual detections insignificant on their own. This information is timely given the recent rapid discovery of new pulsars with the Fermi-LAT t $\\gamma$-ray telescope. Methods: Approximately $10^{14}$ realisations of the H-statistic ($H$) for random (white) noise is calculated from a random number generator for which the repitition cycle is $\\gg 10^{14}$. From these numbers the probability distribution $P(>H)$ is calculated. Results: The distribution of $H$ is is found to be exponential with parameter $\\lambda=0.4$ so that the cumulative probability ...

2010-01-01

116

Single Higgs-boson production at a photon-photon collider: general 2HDM versus MSSM

We study the phenomenological consequences of a four site Higgsless model based on the SU(2)_L x SU(2)_1 x SU(2)_2 x U(1)_Y gauge symmetry, which predicts two neutral and four charged extra gauge bosons, Z_{1,2} and W_{1,2}. The model represents an extension of the minimal three site version (or BESS model), largely investigated in the literature, which includes three heavy vector bosons. We compute the properties of the new particles, and derive indirect and direct limits on their masses and couplings from LEP and Tevatron data and from the perturbative unitarity requirements. In contrast to other Higgsless models characterized by fermiophobic extra gauge bosons, here sizeable fermion-boson couplings are allowed by the electroweak precision data. The prospects of detecting the new predicted particles in the favoured Drell-Yan channel at the LHC are thus investigated. The outcome is that all six extra gauge bosons could be discovered in the early stage of the LHC low-luminosity run.

2010-01-01

117

Safety and Environmental Aspects of Inertial Fusion Energy: An Overview of Recent Activities and Developments in the United States

We revisit the production of a single Higgs boson from direct \\gamma \\gamma -scattering at a photon collider. We compute the total cross section \\sigma(\\gamma \\gamma \\to h) (for h=h0, H0, A0), and the strength of the effective g_{h \\gamma \\gamma} coupling normalized to the Standard Model (SM), for both the general Two-Higgs-Doublet Model (2HDM) and the Minimal Supersymmetric Standard Model (MSSM). In both cases the predicted production rates for the CP-even (odd) states render up to 10^4 (10^3) events per 500 \\invfb of integrated luminosity, in full consistency with all the theoretical and phenomenological constraints. Depending on the channel the maximum rates can be larger or smaller than the SM expectations, but in most of the parameter space they should be well measurable. We analyze how these departures depend on the dynamics underlying each of the models, supersymmetric and non-supersymmetric, and highlight the possible distinctive phenomenological ...

2011-01-01

118

Radiation hardening revisited: role of intracascade clustering

During the past 2 yr, significant progress has been made in several areas related to the safety and environmental (S and E) aspects of inertial fusion energy (IFE). An updated methodology has been developed, and accident analyses have been performed for two IFE conceptual power plants and a target fabrication facility. Parallel to the consequence analyses of different accident scenarios, ongoing studies of accident initiating events are being used to support safety assessment and create a basic framework of types of events to consider in future risk characterization of new plant designs. Target designers/fabrication specialists have been provided with ranking information related to the S and E characteristics of candidate target materials. We have revisited waste management options for IFE, introducing the concept of clearance versus the traditional shallow land burial. A brief summary of results in each of these activities is given, and plans for future work are ...

2003-05-01

119

Promise and Possibility in Special Education Services for Students with Emotional or Behavioral Disorders: Peacock Hill Revisited

Experimental observations related to the initiation of plastic deformation in metals and alloys irradiated with fission neutrons have been analyzed. The experimental results, showing irradiation-induced increase in the upper yield stress followed by a yield drop and plastic instability, cannot be explained in terms of conventional dispersed-barrier hardening because (a) the grown-in dislocations are not free, and (b) irradiation-induced defect clusters are not rigid indestructible Orowan obstacles. A new model called 'cascade-induced source hardening' is presented where glissile loops produced directly in cascades are envisaged to decorate the grown-in dislocations so that they cannot act as dislocation sources. The upper yield stress is related to the breakaway stress which is necessary to pull the dislocation away from the clusters/loops decorating it. The magnitude of the breakaway stress has been estimated and is found to be in good agreement with the measured increase in the ...

120

HD 75289Ab revisited - Searching for starlight reflected from a hot Jupiter

This article provides an historical look at how programs and practices for students with emotional or behavior disorders (E/BD) have been evaluated since 1964, leading to a codified, although not universally recognized, set of recommendations for evaluating best practices for students with E/BD set out by The Peacock Hill Working Group (1991). The authors contend that, in addition to the programmatic features of best practice, the addition of the quality indicators and standards for research in special education add a critical dimension for examining the quality of the scientific research of identified best practices. Taken together, these set of recommendations and quality indicators represent the state of the art in program evaluation for best practice and programs for students with E/BD. The goal of this article is to outline the current recommendations and apply them to current behavior intervention practices to identify how well the field is meeting the criteria. Then, extending ...

2010-08-01

1 2 3 4 5 6 7

121

Experimental Electron Heat Diffusion in TJ-II ECRH Plasmas

Aims. We attempt to detect starlight reflected from a hot Jupiter, orbiting the main-sequence star HD 75289Ab. We report a revised analysis of observations of this planetary system presented previously by another research group. Methods. We analyse high-precision, high-resolution spectra, collected over four nights using UVES at the VLT/UT2, by way of data synthesis. We try to interpret our data using different atmospheric models for hot Jupiters. Results. We do not find any evidence for reflected light, and, therefore, establish revised upper limits to the planet-to-star flux ratio at the 99.9% significance level. At high orbital inclinations, where the best sensitivity is attained, we can limit the relative reflected radiation to be less than e = 6.7 x 10-5 assuming a grey albedo, and e = 8.3 x 10-5 assuming an Class IV function, respectively. This implies a geometric albedo smaller than p = 0.46 and p = 0.57, for the grey albedo and the Class IV albedo shape, respectively, assuming ...

2008-01-01

122

Challenges in environmental monitoring and reporting

Interpretative transport has been used to revisit the global scalings of TJ-II ECRH plasmas from a local perspective. Density, rotational transform and ERCH power scans were analysed based upon Thomson Scattering data (electron density and temperature) in steady state discharges. A simple formula to obtain the thermal conductivity, assuming pure diffusion and negligible convective heat fluxes was used in a set of 161 discharges. All the analysis was performed with the ASTRA transport shell. The density scan indicates that inside n=0,4 there is no significant change of e with density in the range studied (0.4 <ne>(1019m-3) 1.0), while in 0,5 <0,8 approximately, e decreases with density. In the rotational transform scan it is found that the values of e when a low order rational of the rotational transform is present locally seem to be smaller for the corresponding range, although it is apparent a general beneficial effect of the corresponding ...

2006-07-01

123

The life span of the biosphere revisited

The Canadian Association of Petroleum Producers (CAPP) represents about 170 crude oil and natural gas exploration, development and production companies in regulatory hearings and legal proceedings. Its principal role is to enhance the economic well-being and sustainability of the Canadian upstream petroleum industry. This presentation explores the role that information technology (IT) plays in knowledge and information management and how this role relates to meeting Canada`s target for greenhouse gas emissions reductions set by the Kyoto Protocol. Actions such as the Voluntary Challenge Registry (VCR) and emissions reductions trading are re-visited and the information requirements associated with these actions are highlighted. It is shown that among others, emissions databases between jurisdictions (provincial, national, international) have to be integrated, reduction claims must be tracked, verified and cross-referenced to eliminate double counting, comprehensive ...

1998-12-31

124

The Stefan Problem Revisited: A Continuum Model of Frost Heave

A decade ago, Lovelock and Whitfield raised the question of how much longer the biosphere can survive on Earth. They pointed out that, despite the current fossil-fuel induced increase in the atmospheric CO[sub 2] concentration, the long-term trend should be in the opposite direction: as increased solar luminosity warms the Earth, silicate rocks should weather more readily, causing atmospheric CO[sub 2] to decrease. In their model, atmospheric CO[sub 2] falls below the critical level for C3 photosynthesis, 150 parts per million (p.p.m.), in only 100 Myr, and this is assumed to mark the demise of the biosphere as a whole. Here, this problem is re-examined using a more elaborate model that includes a more accurate treatment of the greenhouse effect of CO[sub 2] a biologically mediated weathering parameterization, and the realization that C4 photosynthesis can persist to much lower concentrations of atmospheric CO[sub 2] ([lt]10 p.p.m.). It was found that a C4-plant-based biosphere could ...

1992-12-24

125

THE BURST MODE OF ACCRETION AND DISK FRAGMENTATION IN THE EARLY EMBEDDED STAGES OF STAR FORMATION

The classical Stefan problem describes the motion of a solidification front through a uniform half-space in response to a step change in temperature on its boundary. The predictions of such a model can be applied quite accurately to the freezing of water in a porous medium so long as the pore geometry remains unaltered by the passing solidification front. It is observed, however, that in fine-grained porous media, ice has a tendency to form in segregated horizontal bands, known as ice lenses, that disrupt the regular pattern of heat flow through their enhanced consumption of latent heat. This process, known as frost heave, causes significant ground deformation in regions subject to prolonged freezing, and is one of the most important weathering processes in polar and alpine regions. Recent improvements to our understanding of the mechanics of ice lens nucleation and growth are applied here to predict the conditions and characteristics of frost heave in a step-freezing configuration. ...

2005-12-01

126

Revisit to the helicity and the generalized self-organization theory

We revisit our original papers on the burst mode of accretion by incorporating a detailed energy balance equation into a thin-disk model for the formation and evolution of circumstellar disks around low-mass protostars. Our model includes the effect of radiative cooling, viscous and shock heating, and heating due to stellar and background irradiation. Following the collapse from the prestellar phase allows us to model the early embedded phase of disk formation and evolution. During this time, the disk is susceptible to fragmentation, depending upon the properties of the initial prestellar core. Globally, we find that higher initial core angular momentum and mass content favors more fragmentation, but higher levels of background radiation can moderate the tendency to fragment. A higher rate of mass infall onto the disk than that onto the star is a necessary but not a sufficient condition for disk fragmentation. More locally, both the Toomre Q-parameter needs to be ...

2010-08-20

127

Phase Formation and Transformations in Transmutation Fuel Materials for the LIFE Engine Part I - Path Forward

It is clarified that the so-caned 'helicity conservation law' is never the conservation equation of the helicity K itself', but is merely 'the time change rate equation of K', which is passively and resultantly determined by the mutually independent volume and surface integral terms. It is shown that since the total helicity K can never be conserved in the real experimental systems, the conjecture of the total helicity invariance is not physically available to real magnetized plasmas in an exact sense. The well-known relaxation theory by Dr. J. B. Taylor is clarified to be neither the variational principle nor the energy principle, but be merely a mathematical calculation, using the variational calculus in order to find the minimum magnetic energy solution from the set of solutions having the same value of K. With the use of auto-correlations for physical quantities, it is presented that a novel basic formulation of an extended generalized ...

2000-09-01

128

LIFE Materials: Phase Formation and Transformations in Transmutation Fuel Materials for the LIFE Engine Part I - Path Forward Volume 3

The current specifications of the LLNL fusion-fission hybrid proposal, namely LIFE, impose severe constraints on materials, and in particular on the nuclear fissile or fertile nuclear fuel and its immediate environment. This constitutes the focus of the present report with special emphasis on phase formation and phase transformations of the transmutation fuel and their consequences on particle and pebble thermal, chemical and mechanical integrities. We first review the work that has been done in recent years to improve materials properties under the Gen-IV project, and with in particular applications to HTGR and MSR, and also under GNEP and AFCI in the USA. Our goal is to assess the nuclear fuel options that currently exist together with their issues. Among the options, it is worth mentioning TRISO, IMF, and molten salts. The later option will not be discussed in details since an entire report is dedicated to it. Then, in a second part, with the specific LIFE specifications in mind, ...

2008-11-10

129

Hydrogen embrittlement, revisited by in situ electrochemical nanoindentation

The current specifications of the LLNL fusion-fission hybrid proposal, namely LIFE, impose severe constraints on materials, and in particular on the nuclear fissile or fertile nuclear fuel and its immediate environment. This constitutes the focus of the present report with special emphasis on phase formation and phase transformations of the transmutation fuel and their consequences on particle and pebble thermal, chemical, and mechanical integrities. We first review the work that has been done in recent years to improve materials properties under the Gen-IV project, and with in particular applications to HTGR and MSR, and also under GNEP and AFCI in the USA. Our goal is to assess the nuclear fuel options that currently exist together with their issues. Among the options, it is worth mentioning TRISO, IMF, and molten salts. The later option will not be discussed in details since an entire report (Volume 8 - Molten-salt Fuels) is dedicated to it. Then, in a second part, with the specific ...

2008-12-19

130

GHG emissions, GDP growth and the Kyoto Protocol: A revisit of Environmental Kuznets Curve hypothesis

The fine scale mechanical probing capability of NI-AFM was used to examine hydrogen interaction with plasticity. To realize this, an electrochemical three electrode setup was incorporated into the NI-AFM. The developed ECNI-AFM is capable of performing nanoindentation as well as imaging surfaces inside electrolytes. The developed ECNI-AFM setup was used to examine the effect of cathodically charged hydrogen on dislocation nucleation in pure metals and alloys. It was shown that hydrogen reduces the pop-in load in all of the tested materials except Cu. The reduced pop-in load can be interpreted as the HELP mechanism. Classical dislocation theory was used to model the homogeneous dislocation nucleation and it was shown that H reduces the activation energy for dislocation nucleation in H sensitive metals which are not undergoing a phase transformation. The activation energy for dislocation nucleation is related to the material specific parameters; shear modulus {mu}, dislocation core ...

2007-07-01

131

GHG emissions, GDP growth and the Kyoto Protocol: A revisit of Environmental Kuznets Curve hypothesis

The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis. This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of 'hot air' which is significant to the implementation of the Kyoto Protocol. In addition, through the analysis of single-country time series data and GDP data, this research demonstrated that statistical data for most of the Annex II countries do not possess evidence that ...

2008-01-15

132

Classical tachyons and possible applications

The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis. This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of 'hot air' which is significant to the implementation of the Kyoto Protocol. In addition, through the analysis of single-country time series data and GDP data, this research demonstrated that statistical data for most of the Annex II countries do not possess evidence that ...

2008-01-15

133

Accident analysis in research reactors

This article is divided in five parts, the first one having nothing to do with tachyons. In fact, to prepare the ground, in part I (sect.2) we shall merely show that special relativity - even without tachyons - can be given a form such to describe both particles and antiparticles. Part II is the largest one: initially, after some historical remarks and having revisited the postulates of special relativity, we presnt a review of the elegant ''model theory'' of tachyons in two dimensions; passing then to four dimensions, we review the main results of the classical theory of tachyons that do not depend on the existence of Superluminal reference frames (or that are at least independent of the explicit form of the Superluminal Lorentz ''transformations''). In particular, we discuss how tachyons would look like, i.e. their apparent ''shape''. Last but not least, ...

1986-01-01

134

Antimalarial activity of selected Sudanese medicinal plants with emphasis to Maytenus senegalensis

Full text: Full text: The incomplete understanding of the complex mechanisms connected with the interaction between thermal-hydraulic and neutron kinetics still challenges the design and the operation of nuclear reactors and imposes the adoption of conservatism in the evaluation of safety limits. The recent availability of powerful computer and computational techniques together with the continuing increase in operational experience suggests the revisiting of those areas and the identification of design/operation requirements that can be relaxed. So far, almost all of the safety analyses of research reactors have been performed using conservative computational tools such as channel codes but, nowadays, the application of Best-Estimate (BE) methods constitutes a real necessity. The global aim of the current work is an attempt to apply the best-estimate system thermal-hydraulic code Relap5. For this purpose, the generic IAEA research reactor Benchmark problem is ...

2006-10-15

135

PROBABILISTIC SAFETY ASSESSMENT OF OPERATIONAL ACCIDENTS AT THE WASTE ISOLATION PILOT PLANT

The aim of the present study is to identify and characterize the antimalrial agents from traitional Sudanese medicinal plants. 49 plants parts representing 26 species from 15 families were extracted and screened for their in vitro antimalrial activity using P. falciparum strain 3D7 which is chloroquine sensitive and Dd2 strain which is chloroquine resistant and pyrimethamine sensitive.The plant species investigated exhibited diverse botanical families. They includes Annonaceae, Aristolochiaceae, Asteraceae, Balantiaceae, Caesalpiniceae, Celasteraceae, Cucurbitaceae, Fabaceae, Graminae, Meliaceae, Myrtaceae, Polygonaceae, Rubiaceae, Rutaceae, and simaroubaceae. The evaluation of these plants for their antimalarial activity and their effect on lymphocyte proliferation was carried out. 57 extracts were tested on the chloroquine sensitive strain (3D7). Where 34 extracts (59%) exhibited significant activity against 3D7 with IC_5_0 values #100 #mu# g/ml), where as ...

136