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Sample records for detect local malaria

  1. Microfluidic approaches to malaria detection.

    PubMed

    Gascoyne, Peter; Satayavivad, Jutamaad; Ruchirawat, Mathuros

    2004-02-01

    Microfluidic systems are under development to address a variety of medical problems. Key advantages of micrototal analysis systems based on microfluidic technology are the promise of small size and the integration of sample handling and measurement functions within a single, automated device having low mass-production costs. Here, we review the spectrum of methods currently used to detect malaria, consider their advantages and disadvantages, and discuss their adaptability towards integration into small, automated micro total analysis systems. Molecular amplification methods emerge as leading candidates for chip-based systems because they offer extremely high sensitivity, the ability to recognize malaria species and strain, and they will be adaptable to the detection of new genotypic signatures that will emerge from current genomic-based research of the disease. Current approaches to the development of chip-based molecular amplification are considered with special emphasis on flow-through PCR, and we present for the first time the method of malaria specimen preparation by dielectrophoretic field-flow-fractionation. Although many challenges must be addressed to realize a micrototal analysis system for malaria diagnosis, it is concluded that the potential benefits of the approach are well worth pursuing.

  2. Novel image processing approach to detect malaria

    NASA Astrophysics Data System (ADS)

    Mas, David; Ferrer, Belen; Cojoc, Dan; Finaurini, Sara; Mico, Vicente; Garcia, Javier; Zalevsky, Zeev

    2015-09-01

    In this paper we present a novel image processing algorithm providing good preliminary capabilities for in vitro detection of malaria. The proposed concept is based upon analysis of the temporal variation of each pixel. Changes in dark pixels mean that inter cellular activity happened, indicating the presence of the malaria parasite inside the cell. Preliminary experimental results involving analysis of red blood cells being either healthy or infected with malaria parasites, validated the potential benefit of the proposed numerical approach.

  3. Malaria transmission in two localities in north-western Argentina

    PubMed Central

    Dantur Juri, María J; Zaidenberg, Mario; Claps, Guillermo L; Santana, Mirta; Almirón, Walter R

    2009-01-01

    Background Malaria is one of the most important tropical diseases that affects people globally. The influence of environmental conditions in the patterns of temporal distribution of malaria vectors and the disease has been studied in different countries. In the present study, ecological aspects of the malaria vector Anopheles (Anopheles) pseudopunctipennis and their relationship with climatic variables, as well as the seasonality of malaria cases, were studied in two localities, El Oculto and Aguas Blancas, in north-western Argentina. Methods The fluctuation of An. pseudopunctipennis and the malaria cases distribution was analysed with Random Effect Poisson Regression. This analysis takes into account the effect of each climatic variable on the abundance of both vector and malaria cases, giving as results predicted values named Incidence Rate Radio. Results The number of specimens collected in El Oculto and Aguas Blancas was 4224 (88.07%) and 572 (11.93%), respectively. In El Oculto no marked seasonality was found, different from Aguas Blancas, where high abundance was detected at the end of spring and the beginning of summer. The maximum mean temperature affected the An. pseudopunctipennis fluctuation in El Oculto and Aguas Blancas. When considering the relationship between the number of malaria cases and the climatic variables in El Oculto, maximum mean temperature and accumulated rainfall were significant, in contrast with Aguas Blancas, where mean temperature and humidity showed a closer relationship to the fluctuation in the disease. Conclusion The temporal distribution patterns of An. pseudopunctipennis vary in both localities, but spring appears as the season with better conditions for mosquito development. Maximum mean temperature was the most important variable in both localities. Malaria cases were influenced by the maximum mean temperature in El Oculto, while the mean temperature and humidity were significant in Aguas Blancas. In Aguas Blancas peaks of

  4. Early detection and monitoring of Malaria

    NASA Astrophysics Data System (ADS)

    Rahman, Md Z.; Roytman, Leonid; Kadik, Abdelhamid; Miller, Howard; Rosy, Dilara A.

    2015-05-01

    Global Earth Observation Systems of Systems (GEOSS) are bringing vital societal benefits to people around the globe. In this research article, we engage undergraduate students in the exciting area of space exploration to improve the health of millions of people globally. The goal of the proposed research is to place students in a learning environment where they will develop their problem solving skills in the context of a world crisis (e.g., malaria). Malaria remains one of the greatest threats to public health, particularly in developing countries. The World Health Organization has estimated that over one million die of Malaria each year, with more than 80% of these found in Sub-Saharan Africa. The mosquitoes transmit malaria. They breed in the areas of shallow surface water that are suitable to the mosquito and parasite development. These environmental factors can be detected with satellite imagery, which provide high spatial and temporal coverage of the earth's surface. We investigate on moisture, thermal and vegetation stress indicators developed from NOAA operational environmental satellite data. Using these indicators and collected epidemiological data, it is possible to produce a forecast system that can predict the risk of malaria for a particular geographical area with up to four months lead time. This valuable lead time information provides an opportunity for decision makers to deploy the necessary preventive measures (spraying, treated net distribution, storing medications and etc) in threatened areas with maximum effectiveness. The main objective of the proposed research is to study the effect of ecology on human health and application of NOAA satellite data for early detection of malaria.

  5. Defining and detecting malaria epidemics in south-east Iran

    PubMed Central

    2012-01-01

    Background A lack of consensus on how to define malaria epidemics has impeded the evaluation of early detection systems. This study aimed to develop local definitions of malaria epidemics in a known malarious area of Iran, and to use that definition to evaluate the validity of several epidemic alert thresholds. Methods Epidemic definition variables generated from surveillance data were plotted against weekly malaria counts to assess which most accurately labelled aberrations. Various alert thresholds were then generated from weekly counts or log counts. Finally, the best epidemic definition was used to calculate and compare sensitivities, specificities, detection delays, and areas under ROC curves of the alert thresholds. Results The best epidemic definition used a minimum duration of four weeks and week-specific and overall smoothed geometric means plus 1.0 standard deviation. It defined 13 epidemics. A modified C-SUM alert of untransformed weekly counts using a threshold of mean + 0.25 SD had the highest combined sensitivity and specificity. Untransformed C-SUM alerts also had the highest area under the ROC curve. Conclusions Defining local malaria epidemics using objective criteria facilitated the evaluation of alert thresholds. This approach needs further study to refine epidemic definitions and prospectively evaluate epidemic alerts. PMID:22443235

  6. Rapid transdermal bloodless and reagent-free malaria detection

    NASA Astrophysics Data System (ADS)

    Lukianova-Hleb, Ekaterina Y.; Campbell, Kelly M.; Constantinou, Pamela E.; Braam, Janet; Olson, John S.; Ware, Russell E.; Sullivan, David S.; Lapotko, Dmitri

    2014-02-01

    Successful diagnosis, screening, and elimination of malaria critically depend on rapid and sensitive detection of this dangerous infection, preferably transdermally and without sophisticated reagents or blood drawing. Such diagnostic methods are not currently available. Here we show that the high optical absorbance and nanosize of endogenous heme nanoparticles called hemozoin, a unique component of all blood-stage malaria parasites, generate a transient vapor nanobubble around hemozoin in response to a short and safe near-infrared picosecond laser pulse. The acoustic signals of these malaria-specific nanobubbles provided the first transdermal non-invasive and rapid detection of a malaria infection as low as 0.00034% in animals without using any reagents or drawing blood. These on-demand transient events have no analogs among current malaria markers and probes, can detect and screen malaria in seconds and can be realized as a compact, easy to use, inexpensive and safe field technology.

  7. Anopheles ziemanni a locally important malaria vector in Ndop health district, north west region of Cameroon

    PubMed Central

    2014-01-01

    Background Malaria transmission in Cameroon is mediated by a plethora of vectors that are heterogeneously distributed across the country depending on the biotope. To effectively guide malaria control operations, regular update on the role of local Anopheles species is essential. Therefore, an entomological survey was conducted between August 2010 and May 2011 to evaluate the role of the local anopheline population in malaria transmission in three villages of the Ndop health district in the northwest region of Cameroon where malaria is holoendemic, as a means to acquiring evidence based data for improved vector intervention. Methods Mosquitoes were sampled both indoor and outdoor for four consecutive nights in each locality during each month of survey. Sampling was done by the human landing catch method on volunteers. Anopheles species were identified morphologically and their ovaries randomly dissected for parity determination. Infection with Plasmodium falciparum was detected by Circumsporozoite protein ELISA. Members of An. gambiae complex were further identified to molecular level by PCR and RFLP PCR. Results An. ziemanni was the main malaria vector and whether outdoor or indoor. The man biting rate for the vectors ranged from 6.75 to 8.29 bites per person per night (b/p/n). The entomological inoculation rate for this vector species was 0.0278 infectious bites per person per night (ib/p/n) in Mbapishi, 0.034 ib/p/n in Mbafuh, and 0.063 ib/p/n in Backyit. These were by far greater than that for An. gambiae. No difference was observed in the parity rate of these two vectors. PCR analysis revealed the presence of only An. colluzzi (M- form). Conclusions An. ziemanni is an important local malaria vector in Ndop health district. The findings provide useful baseline information on the anopheles species composition, their distribution and role in malaria transmission that would guide the implementation of integrated vector management strategies in the locality. PMID

  8. Local transmission of Plasmodium vivax malaria--Palm Beach County, Florida, 2003.

    PubMed

    2003-09-26

    The majority of malaria cases diagnosed in the United States are imported, usually by persons who travel to countries where malaria is endemic. However, small outbreaks of locally acquired mosquito-transmitted malaria continue to occur. Despite certification of malaria eradication in the United States in 1970, 11 outbreaks involving 20 cases of probable locally acquired mosquito-transmitted malaria have been reported to CDC since 1992, including two reported in July 1996 from Palm Beach County, Florida (Palm Beach County Health Department, unpublished data, 1998). This report describes the investigation of seven cases of locally acquired Plasmodium vivax malaria that occurred in Palm Beach County during July-August 2003. In addition to considering malaria in the differential diagnosis for febrile patients with a history of travel to malarious areas, health-care providers also should consider malaria as a possible cause of fever among patients who have not traveled but are experiencing alternating fevers, rigors, and sweats with no obvious cause.

  9. The incidence of malaria in travellers to South-East Asia: is local malaria transmission a useful risk indicator?

    PubMed Central

    2010-01-01

    Background The presence of ongoing local malaria transmission, identified though local surveillance and reported to regional WHO offices, by S-E Asian countries, forms the basis of national and international chemoprophylaxis recommendations in western countries. The study was designed to examine whether the strategy of using malaria transmission in a local population was an accurate estimate of the malaria threat faced by travellers and a correlate of malaria in returning travellers. Methods Malaria endemicity was described from distribution and intensity in the local populations of ten S-E Asian destination countries over the period 2003-2008 from regionally reported cases to WHO offices. Travel acquired malaria was collated from malaria surveillance reports from the USA and 12 European countries over the same period. The numbers of travellers visiting the destination countries was based on immigration and tourism statistics collected on entry of tourists to the destination countries. Results In the destination countries, mean malaria rates in endemic countries ranged between 0.01 in Korea to 4:1000 population per year in Lao PDR, with higher regional rates in a number of countries. Malaria cases imported into the 13 countries declined by 47% from 140 cases in 2003 to 66 in 2008. A total of 608 cases (27.3% Plasmodium falciparum (Pf)) were reported over the six years, the largest number acquired in Indonesia, Thailand and Korea. Four countries had an incidence > 1 case per 100,000 traveller visits; Burma (Myanmar), Indonesia, Cambodia and Laos (range 1 to 11.8-case per 100,000 visits). The remaining six countries rates were < 1 case per 100,000 visits. The number of visitors arriving from source countries increased by 60% from 8.5 Million to 13.6 million over the 6 years. Conclusion The intensity of malaria transmission particularly sub-national activity did not correlate with the risk of travellers acquiring malaria in the large numbers of arriving visitors. It

  10. Malaria

    MedlinePlus

    ... common?Malaria is a health problem in many tropical and subtropical countries, including portions of Central and ... these countries. If you are traveling to a tropical area or to a country where malaria is ...

  11. Malaria.

    ERIC Educational Resources Information Center

    Dupasquier, Isabelle

    1989-01-01

    Malaria, the greatest pandemia in the world, claims an estimated one million lives each year in Africa alone. While it may still be said that for the most part malaria is found in what is known as the world's poverty belt, cases are now frequently diagnosed in western countries. Due to resistant strains of malaria which have developed because of…

  12. Malaria

    PubMed Central

    Suh, Kathryn N.; Kain, Kevin C.; Keystone, Jay S.

    2004-01-01

    Malaria is a parasitic infection of global importance. Although relatively uncommon in developed countries, where the disease occurs mainly in travellers who have returned from endemic regions, it remains one of the most prevalent infections of humans worldwide. In endemic regions, malaria is a significant cause of morbidity and mortality and creates enormous social and economic burdens. Current efforts to control malaria focus on reducing attributable morbidity and mortality. Targeted chemoprophylaxis and use of insecticide-treated bed nets have been successful in some endemic areas. For travellers to malaria-endemic regions, personal protective measures and appropriate chemoprophylaxis can significantly reduce the risk of infection. Prompt evaluation of the febrile traveller, a high degree of suspicion of malaria, rapid and accurate diagnosis, and appropriate antimalarial therapy are essential in order to optimize clinical outcomes of infected patients. Additional approaches to malaria control, including genetic manipulation of mosquitoes and malaria vaccines, are areas of ongoing research. PMID:15159369

  13. Potential Biomarkers and Their Applications for Rapid and Reliable Detection of Malaria

    PubMed Central

    Jain, Priyamvada; Chakma, Babina; Patra, Sanjukta; Goswami, Pranab

    2014-01-01

    Malaria has been responsible for the highest mortality in most malaria endemic countries. Even after decades of malaria control campaigns, it still persists as a disease of high mortality due to improper diagnosis and rapidly evolving drug resistant malarial parasites. For efficient and economical malaria management, WHO recommends that all malaria suspected patients should receive proper diagnosis before administering drugs. It is thus imperative to develop fast, economical, and accurate techniques for diagnosis of malaria. In this regard an in-depth knowledge on malaria biomarkers is important to identify an appropriate biorecognition element and utilize it prudently to develop a reliable detection technique for diagnosis of the disease. Among the various biomarkers, plasmodial lactate dehydrogenase and histidine-rich protein II (HRP II) have received increasing attention for developing rapid and reliable detection techniques for malaria. The widely used rapid detection tests (RDTs) for malaria succumb to many drawbacks which promotes exploration of more efficient economical detection techniques. This paper provides an overview on the current status of malaria biomarkers, along with their potential utilization for developing different malaria diagnostic techniques and advanced biosensors. PMID:24804253

  14. Malaria

    MedlinePlus

    ... a parasite. You get it when an infected mosquito bites you. Malaria is a major cause of ... insect repellent with DEET Cover up Sleep under mosquito netting Centers for Disease Control and Prevention

  15. Malaria

    MedlinePlus

    ... Malaria can be carried by mosquitoes in temperate climates, but the parasite disappears over the winter. The ... a major disease hazard for travelers to warm climates. In some areas of the world, mosquitoes that ...

  16. Malaria

    DTIC Science & Technology

    2011-06-01

    established, the infection is classi- fied as cryptic malaria. A large majority of infections are transmitted by the bite of an infected female ... female anopheline mosquitoes. Plasmodium sp infecting humans include Plasmodium vivax, Plasmodium falci- parum, Plasmodium malariae, and Plasmodium ovale...paled and pigment formed within them. Later he observed male gametes form by exflagellation and described the male and female gam- etes, the

  17. Testing Local Adaptation in a Natural Great Tit-Malaria System: An Experimental Approach

    PubMed Central

    Jenkins, Tania; Delhaye, Jessica; Christe, Philippe

    2015-01-01

    Finding out whether Plasmodium spp. are coevolving with their vertebrate hosts is of both theoretical and applied interest and can influence our understanding of the effects and dynamics of malaria infection. In this study, we tested for local adaptation as a signature of coevolution between malaria blood parasites, Plasmodium spp. and its host, the great tit, Parus major. We conducted a reciprocal transplant experiment of birds in the field, where we exposed birds from two populations to Plasmodium parasites. This experimental set-up also provided a unique opportunity to study the natural history of malaria infection in the wild and to assess the effects of primary malaria infection on juvenile birds. We present three main findings: i) there was no support for local adaptation; ii) there was a male-biased infection rate; iii) infection occurred towards the end of the summer and differed between sites. There were also site-specific effects of malaria infection on the hosts. Taken together, we present one of the few experimental studies of parasite-host local adaptation in a natural malaria system, and our results shed light on the effects of avian malaria infection in the wild. PMID:26555892

  18. Malaria.

    PubMed

    Heck, J E

    1991-03-01

    Human malaria is caused by four species of the genus plasmodium. The sexual stage of the parasite occurs in the mosquito and asexual reproduction occurs in man. Symptoms of fever, chills, headache, and myalgia result from the invasion and rupture of erythrocytes. Merozoites are released from erythrocytes and invade other cells, thus propagating the infection. The most vulnerable hosts are nonimmune travelers, young children living in the tropics, and pregnant women. P. falciparum causes the most severe infections because it infects RBCs of all ages and has the propensity to develop resistance to antimalarials. Rapid diagnosis can be made with a malarial smear, and treatment should be initiated promptly. In some regions (Mexico, Central America except Panama, and North Africa) chloroquine phosphate is effective therapy. In subsaharan Africa, South America, and Southeast Asia, chloroquine resistance has become widespread, and other antimalarials are necessary. The primary care physician should have a high index of suspicion for malaria in the traveler returning from the tropics. Malaria should also be suspected in the febrile transfusion recipient and newborns of mothers with malaria.

  19. Uncomplicated malaria among pregnant women in the Brazilian Amazon: local barriers to prompt and effective case management.

    PubMed

    Luz, Tatiana Chama Borges; Suárez-Mutis, Martha Cecília; Miranda, Elaine Silva; Moritz, Angela Fernandes Esher; Freitas, Letícia Figueira; Brasil, Juliana de Castro; Osorio-de-Castro, Claudia Garcia Serpa

    2013-02-01

    Malaria in pregnancy is associated with increased risks of maternal anemia, spontaneous abortion, low birth weight, premature delivery and other adverse effects on health. In Brazil, disease transmission is highly concentrated in the multi-state region that constitutes the Brazilian Amazon (more than 99% of all cases). This study, conducted between the first bimesters of 2007 and 2008, aims to identify the local barriers to prompt and effective case management of malaria in pregnancy and was carried out in health facilities located in three endemic municipalities of the Brazilian Amazon (Manaus, Presidente Figueiredo and Porto Velho). The study design combined both qualitative and quantitative descriptive methods. The qualitative design involved semi-structured interviews with health personnel who routinely deal with malaria care. The quantitative design involved a review of medical records of pregnant women in the visited health facilities. Additionally, data were abstracted from SIVEP-Malaria Epidemiological Surveillance Information System (Brasil, 2007) and Primary Care Information System (SIAB) databases. Flaws were detected in diagnosis (only 6.8% of women tested for malaria) and treatment (for Plasmodium falciparum infections, only 44.8% of patients received recommended first-line therapy; 10.2% of prescription presented treatments were not found in national guideline and 7.3% of the prescriptions for Plasmodium vivax and 17.9% of the prescriptions for P. falciparum were not sanctioned by the official guidelines). Training (only 37.3% had had some training), knowledge and counseling were also sub-optimal. These results indicated the need to improve the health-worker performance through training. Close supervision and feedback on the health-worker performance are also needed. These findings also highlighted the need to put into practice a series of government recommendations that encourage close collaboration between the National Malaria Control Program and

  20. Reactive Case Detection for Plasmodium vivax Malaria Elimination in Rural Amazonia

    PubMed Central

    Fontoura, Pablo S.; Finco, Bruna F.; Lima, Nathália F.; de Carvalho, Jaques F.; Vinetz, Joseph M.

    2016-01-01

    Background Malaria burden in Brazil has reached its lowest levels in 35 years and Plasmodium vivax now accounts for 84% of cases countrywide. Targeting residual malaria transmission entrenched in the Amazon is the next major challenge for ongoing elimination efforts. Better strategies are urgently needed to address the vast reservoir of asymptomatic P. vivax carriers in this and other areas approaching malaria elimination. Methods We evaluated a reactive case detection (RCD) strategy tailored for P. vivax transmission in farming settlements in the Amazon Basin of Brazil. Over six months, 41 cases detected by passive surveillance triggered four rounds of RCD (0, 30, 60, and 180 days after index case enrollment), using microscopy- and quantitative real-time polymerase chain reaction (qPCR)-based diagnosis, comprising subjects sharing the household (HH) with the index case (n = 163), those living in the 5 nearest HHs within 3 km (n = 878), and individuals from 5 randomly chosen control HHs located > 5 km away from index cases (n = 841). Correlates of infection were identified with mixed-effects logistic regression models. Molecular genotyping was used to infer local parasite transmission networks. Principal findings/Conclusions Subjects in index and neighbor HHs were significantly more likely to be parasitemic than control HH members, after adjusting for potential confounders, and together harbored > 90% of the P. vivax biomass in study subjects. Clustering patterns were temporally stable. Four rounds of microscopy-based RCD would identify only 49.5% of the infections diagnosed by qPCR, but 76.8% of the total parasite biomass circulating in the proximity of index HHs. However, control HHs accounted for 27.6% of qPCR-positive samples, 92.6% of them from asymptomatic carriers beyond the reach of RCD. Molecular genotyping revealed high P. vivax diversity, consistent with complex transmission networks and multiple sources of infection within clusters, potentially

  1. Local-scale variation in malaria infection amongst rural Gambian children estimated by satellite remote sensing.

    PubMed

    Thomas, C J; Lindsay, S W

    2000-01-01

    We investigated local-scale variation in malaria transmission and infection in children within a continuous landscape by retrospective spatial analysis of entomological and clinical data collected during 1988 and 1989 in The Gambia, West Africa. Parasite prevalence was negatively correlated with vector abundance and exposure to malaria parasites in 10 villages where entomological surveillance had been carried out. Variation in bednet use did not explain this finding. Mosquito-breeding habitat was retrospectively mapped using 20-m spatial resolution multispectral SPOT satellite imagery from 1988. From these data we estimated by linear regression the risk of exposure to malaria parasites in 26 villages where clinical surveys of children had been made. As exposure increased, so did parasite prevalence; but at higher levels of exposure, parasite prevalence declined. Our findings demonstrate marked differences in exposure to malaria in villages over distances of less than 2 km from mosquito breeding sites and suggest that there are also large differences in immunity between neighbouring settlements.

  2. Local Adaptation and Vector-Mediated Population Structure in Plasmodium vivax Malaria

    PubMed Central

    Gonzalez-Ceron, Lilia; Carlton, Jane M.; Gueye, Amy; Fay, Michael; McCutchan, Thomas F.; Su, Xin-zhuan

    2008-01-01

    Plasmodium vivax in southern Mexico exhibits different infectivities to 2 local mosquito vectors, Anopheles pseudopunctipennis and Anopheles albimanus. Previous work has tied these differences in mosquito infectivity to variation in the central repeat motif of the malaria parasite's circumsporozoite (csp) gene, but subsequent studies have questioned this view. Here we present evidence that P. vivax in southern Mexico comprised 3 genetic populations whose distributions largely mirror those of the 2 mosquito vectors. Additionally, laboratory colony feeding experiments indicate that parasite populations are most compatible with sympatric mosquito species. Our results suggest that reciprocal selection between malaria parasites and mosquito vectors has led to local adaptation of the parasite. Adaptation to local vectors may play an important role in generating population structure in Plasmodium. A better understanding of coevolutionary dynamics between sympatric mosquitoes and parasites will facilitate the identification of molecular mechanisms relevant to disease transmission in nature and provide crucial information for malaria control. PMID:18385220

  3. A Multi-detection Assay for Malaria Transmitting Mosquitoes

    PubMed Central

    Lee, Yoosook; Weakley, Allison M.; Nieman, Catelyn C.; Malvick, Julia; Lanzaro, Gregory C.

    2015-01-01

    The Anopheles gambiae species complex includes the major malaria transmitting mosquitoes in Africa. Because these species are of such medical importance, several traits are typically characterized using molecular assays to aid in epidemiological studies. These traits include species identification, insecticide resistance, parasite infection status, and host preference. Since populations of the Anopheles gambiae complex are morphologically indistinguishable, a polymerase chain reaction (PCR) is traditionally used to identify species. Once the species is known, several downstream assays are routinely performed to elucidate further characteristics. For instance, mutations known as KDR in a para gene confer resistance against DDT and pyrethroid insecticides. Additionally, enzyme-linked immunosorbent assays (ELISAs) or Plasmodium parasite DNA detection PCR assays are used to detect parasites present in mosquito tissues. Lastly, a combination of PCR and restriction enzyme digests can be used to elucidate host preference (e.g., human vs. animal blood) by screening the mosquito bloodmeal for host-specific DNA. We have developed a multi-detection assay (MDA) that combines all of the aforementioned assays into a single multiplex reaction genotyping 33SNPs for 96 or 384 samples at a time. Because the MDA includes multiple markers for species, Plasmodium detection, and host blood identification, the likelihood of generating false positives or negatives is greatly reduced from previous assays that include only one marker per trait. This robust and simple assay can detect these key mosquito traits cost-effectively and in a fraction of the time of existing assays. PMID:25867057

  4. Enhancing malaria diagnosis through microfluidic cell enrichment and magnetic resonance relaxometry detection

    NASA Astrophysics Data System (ADS)

    Fook Kong, Tian; Ye, Weijian; Peng, Weng Kung; Wei Hou, Han; Marcos; Preiser, Peter Rainer; Nguyen, Nam-Trung; Han, Jongyoon

    2015-06-01

    Despite significant advancements over the years, there remains an urgent need for low cost diagnostic approaches that allow for rapid, reliable and sensitive detection of malaria parasites in clinical samples. Our previous work has shown that magnetic resonance relaxometry (MRR) is a potentially highly sensitive tool for malaria diagnosis. A key challenge for making MRR based malaria diagnostics suitable for clinical testing is the fact that MRR baseline fluctuation exists between individuals, making it difficult to detect low level parasitemia. To overcome this problem, it is important to establish the MRR baseline of each individual while having the ability to reliably determine any changes that are caused by the infection of malaria parasite. Here we show that an approach that combines the use of microfluidic cell enrichment with a saponin lysis before MRR detection can overcome these challenges and provide the basis for a highly sensitive and reliable diagnostic approach of malaria parasites. Importantly, as little as 0.0005% of ring stage parasites can be detected reliably, making this ideally suited for the detection of malaria parasites in peripheral blood obtained from patients. The approaches used here are envisaged to provide a new malaria diagnosis solution in the near future.

  5. Enhancing malaria diagnosis through microfluidic cell enrichment and magnetic resonance relaxometry detection

    PubMed Central

    Fook Kong, Tian; Ye, Weijian; Peng, Weng Kung; Wei Hou, Han; Marcos, M; Preiser, Peter Rainer; Nguyen, Nam-Trung; Han, Jongyoon

    2015-01-01

    Despite significant advancements over the years, there remains an urgent need for low cost diagnostic approaches that allow for rapid, reliable and sensitive detection of malaria parasites in clinical samples. Our previous work has shown that magnetic resonance relaxometry (MRR) is a potentially highly sensitive tool for malaria diagnosis. A key challenge for making MRR based malaria diagnostics suitable for clinical testing is the fact that MRR baseline fluctuation exists between individuals, making it difficult to detect low level parasitemia. To overcome this problem, it is important to establish the MRR baseline of each individual while having the ability to reliably determine any changes that are caused by the infection of malaria parasite. Here we show that an approach that combines the use of microfluidic cell enrichment with a saponin lysis before MRR detection can overcome these challenges and provide the basis for a highly sensitive and reliable diagnostic approach of malaria parasites. Importantly, as little as 0.0005% of ring stage parasites can be detected reliably, making this ideally suited for the detection of malaria parasites in peripheral blood obtained from patients. The approaches used here are envisaged to provide a new malaria diagnosis solution in the near future. PMID:26081638

  6. Detection of malaria infection in blood transfusion: a comparative study among real-time PCR, rapid diagnostic test and microscopy: sensitivity of Malaria detection methods in blood transfusion.

    PubMed

    Hassanpour, Gholamreza; Mohebali, Mehdi; Raeisi, Ahmad; Abolghasemi, Hassan; Zeraati, Hojjat; Alipour, Mohsen; Azizi, Ebrahim; Keshavarz, Hossein

    2011-06-01

    The transmission of malaria by blood transfusion was one of the first transfusion-transmitted infections recorded in the world. Transfusion-transmitted malaria may lead to serious problems because infection with Plasmodium falciparum may cause rapidly fatal death. This study aimed to compare real-time polymerase chain reaction (real-time PCR) with rapid diagnostic test (RDT) and light microscopy for the detection of Plasmodium spp. in blood transfusion, both in endemic and non-endemic areas of malaria disease in Iran. Two sets of 50 blood samples were randomly collected. One set was taken from blood samples donated in blood bank of Bandar Abbas, a city located in a malarious-endemic area, and the other set from Tehran, a non-endemic one. Light microscopic examination on both thin and thick smears, RDTs, and real-time PCR were performed on the blood samples and the results were compared. Thin and thick light microscopic examinations of all samples as well as RDT results were negative for Plasmodium spp. Two blood samples from endemic area were positive only with real-time PCR. It seems that real-time PCR as a highly sensitive method can be helpful for the confirmation of malaria infection in different units of blood transfusion organization especially in malaria-endemic areas where the majority of donors may be potentially infected with malaria parasites.

  7. “Tazomoka Is Not a Problem”. Local Perspectives on Malaria, Fever Case Management and Bed Net Use in Madagascar

    PubMed Central

    Raboanary, Emma; Kesteman, Thomas; Piola, Patrice; Randrianarivelojosia, Milijaona; Rogier, Christophe

    2016-01-01

    Background Although its incidence has been decreasing during the last decade, malaria is still a major public health issue in Madagascar. The use of Long Lasting Insecticidal Nets (LLIN) remains a key malaria control intervention strategy in Madagascar, however, it encounters some obstacles. The present study aimed to explore the local terminology related to malaria, information channels about malaria, attitude towards bed nets, and health care seeking practices in case of fever. This article presents novel qualitative findings about malaria. Until now, no such data has been published for Madagascar. Methods A comparative qualitative study was carried out at four sites in Madagascar, each differing by malaria epidemiology and socio-cultural background of the populations. Seventy-one semi-structured interviews were conducted with biomedical and traditional caregivers, and members of the local population. In addition, observations of the living conditions and the uses of bed net were conducted. Results Due to the differences between local and biomedical perspectives on malaria, official messages did not have the expected impact on population in terms of prevention and care seeking behaviors. Rather, most information retained about malaria was spread through informal information circulation channels. Most interviewees perceived malaria as a disease that is simple to treat. Tazomoka (“mosquito fever”), the Malagasy biomedical word for malaria, was not used by populations. Tazo (“fever”) and tazomahery (“strong fever”) were the terms more commonly used by members of the local population to refer to malaria related symptoms. According to local perceptions in all areas, tazo and tazomahery were not caused by mosquitos. Each of these symptoms required specific health recourse. The usual fever management strategies consisted of self-medication or recourse to traditional and biomedical caregivers. Usage of bed nets was intermittent and was not directly linked to

  8. Malaria detection with the Sysmex XE-2100 hematology analyzer using pseudoeosinophilia and abnormal WBC scattergram.

    PubMed

    Huh, Hee Jin; Oh, Gwi Young; Huh, Jung Won; Chae, Seok Lae

    2008-09-01

    Recent investigation using the Sysmex XE-2100 hematology analyzer (Sysmex Corporation, Japan) has demonstrated erroneously high eosinophil counts and abnormal white blood cell (WBC) scattergrams in malaria cases. This study was conducted to assess the diagnostic efficiency of the Sysmex XE-2100 analyzer for malaria. One hundred forty-four patients initially diagnosed with Plasmodium vivax infection, 319 patients with febrile illness, and 24 patients who underwent malaria treatment were analyzed. Atypical features on Sysmex XE-2100 analyzer were categorized as pseudoeosinophilia (a gap of more than 5% in eosinophil counts between the Sysmex XE-2100 analyzer and microscopic examination) and abnormal WBC scattergram. Pseudoeosinophilia or abnormal WBC scattergram were detected in 100 of 144 malaria-positive samples (sensitivity 69.4%, specificity 100%). The samples with pseudoeosinophilia or abnormal WBC scattergrams showed significantly higher parasite counts than the samples without pseudoeosinophilia or an abnormal WBC scattergram (P<0.05). All 24 samples from patients for whom the malaria smear was repeated after malaria treatment was initiated showed a normalized eosinophil count and a normal WBC histogram. In conclusion, attention to differential count and WBC scattergrams provided by the Sysmex XE-2100 would be a valuable tool in malaria detection.

  9. New insight-guided approaches to detect, cure, prevent and eliminate malaria.

    PubMed

    Kumar, Sushil; Kumari, Renu; Pandey, Richa

    2015-05-01

    New challenges posed by the development of resistance against artemisinin-based combination therapies (ACTs) as well as previous first-line therapies, and the continuing absence of vaccine, have given impetus to research in all areas of malaria control. This review portrays the ongoing progress in several directions of malaria research. The variants of RTS,S and apical membrane antigen 1 (AMA1) are being developed and test adapted as multicomponent and multistage malaria control vaccines, while many other vaccine candidates and methodologies to produce antigens are under experimentation. To track and prevent the spread of artemisinin resistance from Southeast Asia to other parts of the world, rolling circle-enhanced enzyme activity detection (REEAD), a time- and cost-effective malaria diagnosis in field conditions, and a DNA marker associated with artemisinin resistance have become available. Novel mosquito repellents and mosquito trapping and killing techniques much more effective than the prevalent ones are undergoing field testing. Mosquito lines stably infected with their symbiotic wild-type or genetically engineered bacteria that kill sympatric malaria parasites are being constructed and field tested for stopping malaria transmission. A complementary approach being pursued is the addition of ivermectin-like drug molecules to ACTs to cure malaria and kill mosquitoes. Experiments are in progress to eradicate malaria mosquito by making it genetically male sterile. High-throughput screening procedures are being developed and used to discover molecules that possess long in vivo half life and are active against liver and blood stages for the fast cure of malaria symptoms caused by simple or relapsing and drug-sensitive and drug-resistant types of varied malaria parasites, can stop gametocytogenesis and sporogony and could be given in one dose. Target-based antimalarial drug designing has begun. Some of the putative next-generation antimalarials that possess in their

  10. Local mate competition and transmission bottlenecks: a new model for understanding malaria parasite and other sex ratios.

    PubMed

    Neal, Allison T; Taylor, Peter D

    2014-12-21

    The local mate competition model from sex ratio theory predicts female-biased sex ratios in populations that are highly subdivided during mating, and is thought to accord well with the population structure of malaria parasites. However, the selective advantage of female-biased sex ratios comes from the resulting increase in total reproductive output, an advantage the transmission biology of malaria parasite likely reduces. We develop a mathematical model to determine how bottlenecks in transmission that cause diminishing fitness returns from female production affect sex ratio evolution. We develop four variations of this model that incorporate whether or not parasite clones have the ability to detect others that occupy the same host and whether or not the number of clones affects the total mating population size. Our model indicates that transmission bottlenecks favor less female-biased sex ratios than those predicted under LMC. This effect is particularly pronounced if clones have no information about the presence of coexisting clones and the number of mating individuals per patch is fixed. The model could extend our understanding of malaria parasite sex ratios in three main ways. First, it identifies inconsistencies between the theoretical predictions and the data presented in a previous study, and proposes revised predictions that are more consistent with underlying biology of the parasite. Second, it may account for the positive association between parasite density and sex ratio observed within and between some species. Third, it predicts a relationship between mortality rates in the vector and sex ratios, which appears to be supported by the little existing data we have. While the inspiration for this model came from malaria parasites, it should apply to any system in which per capita dispersal success diminishes with increasing numbers of females in a patch.

  11. High-throughput pooling and real-time PCR-based strategy for malaria detection.

    PubMed

    Taylor, Steve M; Juliano, Jonathan J; Trottman, Paul A; Griffin, Jennifer B; Landis, Sarah H; Kitsa, Paluku; Tshefu, Antoinette K; Meshnick, Steven R

    2010-02-01

    Molecular assays can provide critical information for malaria diagnosis, speciation, and drug resistance, but their cost and resource requirements limit their application to clinical malaria studies. This study describes the application of a resource-conserving testing algorithm employing sample pooling for real-time PCR assays for malaria in a cohort of 182 pregnant women in Kinshasa. A total of 1,268 peripheral blood samples were collected during the study. Using a real-time PCR assay that detects all Plasmodium species, microscopy-positive samples were amplified individually; the microscopy-negative samples were amplified after pooling the genomic DNA (gDNA) of four samples prior to testing. Of 176 microscopy-positive samples, 74 were positive by the real-time PCR assay; the 1,092 microscopy-negative samples were initially amplified in 293 pools, and subsequently, 35 samples were real-time PCR positive (3%). With the real-time PCR result as the referent standard, microscopy was 67.9% sensitive (95% confidence interval [CI], 58.3% to 76.5%) and 91.2% specific (95% CI, 89.4% to 92.8%) for malaria. In total, we detected 109 parasitemias by real-time PCR and, by pooling samples, obviated over 50% of reactions and halved the cost of testing. Our study highlights both substantial discordance between malaria diagnostics and the utility and parsimony of employing a sample pooling strategy for molecular diagnostics in clinical and epidemiologic malaria studies.

  12. Serologic markers for detecting malaria in areas of low endemicity, Somalia, 2008.

    PubMed

    Bousema, Teun; Youssef, Randa M; Cook, Jackie; Cox, Jonathan; Alegana, Victor A; Amran, Jamal; Noor, Abdisalan M; Snow, Robert W; Drakeley, Chris

    2010-03-01

    Areas in which malaria is not highly endemic are suitable for malaria elimination, but assessing transmission is difficult because of lack of sensitivity of commonly used methods. We evaluated serologic markers for detecting variation in malaria exposure in Somalia. Plasmodium falciparum or P. vivax was not detected by microscopy in cross-sectional surveys of samples from persons during the dry (0/1,178) and wet (0/1,128) seasons. Antibody responses against P. falciparum or P. vivax were detected in 17.9% (179/1,001) and 19.3% (202/1,044) of persons tested. Reactivity against P. falciparum was significantly different between 3 villages (p<0.001); clusters of seroreactivity were present. Distance to the nearest seasonal river was negatively associated with P. falciparum (p = 0.028) and P. vivax seroreactivity (p = 0.016). Serologic markers are a promising tool for detecting spatial variation in malaria exposure and evaluating malaria control efforts in areas where transmission has decreased to levels below the detection limit of microscopy.

  13. Assessing Knowledge and Perceptions Related to Preventive Methods and Treatment of Malaria in the Local Endemic Area of Trujillo, Honduras.

    PubMed

    Campodonico, Joanna; Sevilla-Martir, Javier; Arrizabalaga, Gustavo; Kochhar, Komal

    2015-01-01

    Malaria in Honduras is endemic and accounts for 40% of the total cases in Central America. Our goal was to assess knowledge of preventive methods and current treatment of malaria among the affected community of Trujillo, Honduras. A cross-sectional survey was administered to 71 individuals. Most respondents had a good understanding about common malaria symptoms but not about the complications associated with severe cases. More important, we found that less than 20% of the respondents recognized indoor residual sprays and insecticide-treated nets as effective preventive measures, which are the most efficient preventive methods. Our study highlights the perceptions the people of Trujillo have about malaria. From our observations, we put forward recommendations to implement a comprehensive campaign to educate the Trujillo population about malaria preventive methods and to recruit local and international efforts to distribute insecticide-treated nets.

  14. New molecular detection methods of malaria parasites with multiple genes from genomes.

    PubMed

    Gupta, Himanshu; Srivastava, Shikha; Chaudhari, Sima; Vasudevan, Thanvanthri G; Hande, Manjunath H; D'souza, Sydney C; Umakanth, Shashikiran; Satyamoorthy, Kapaettu

    2016-08-01

    For the effective control of malaria, development of sensitive, accurate and rapid tool to diagnose and manage the disease is essential. In humans subjects, the severe form of malaria is caused by Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) and there is need to identify these parasites in acute, chronic and latent (during and post-infection) stages of the disease. In this study, we report a species specific and sensitive diagnostic method for the detection of Pf and Pv in humans. First, we identified intra and intergenic multiloci short stretch of 152 (PfMLS152) and 110 (PvMLS110) nucleotides which is present up to 44 and 34 times in the genomes of Pf and Pv respectively. We developed the single-step amplification-based method using isolated DNA or from lysed red blood cells for the detection of the two malaria parasites. The limit of detection of real-time polymerase chain reaction based assays were 0.1copyof parasite/μl for PfMLS152 and PvMLS110 target sequences. Next, we have tested 250 clinically suspected cases of malaria to validate the method. Sensitivity and specificity for both targets were 100% compared to the quantitative buffy coat microscopy analysis and real-time PCR (Pf-chloroquine resistance transporter (PfCRT) and Pv-lactate dehydrogenase (PvLDH)) based assays. The sensitivity of microscopy and real-time PCR (PfCRT and PvLDH primers) assays were 80.63%; 95%CI 75.22%-85.31%; p<0.05 and 97.61%; 95%CI 94.50%-99.21%; p<0.05 in detecting malaria infection respectively when compared to PfMLS152 and PvMLS110 targets to identify malaria infection in patients. These improved assays may have potential applications in evaluating malaria in asymptomatic patients, treatment, blood donors and in vaccine studies.

  15. Local population structure of Plasmodium: impact on malaria control and elimination

    PubMed Central

    2012-01-01

    Background Regardless of the growing interest in detecting population structures in malarial parasites, there have been limited discussions on how to use this concept in control programmes. In such context, the effects of the parasite population structures will depend on interventions’ spatial or temporal scales. This investigation explores the problem of identifying genetic markers, in this case microsatellites, to unveil Plasmodium genetic structures that could affect decisions in the context of elimination. The study was performed in a low-transmission area, which offers a good proxy to better understand problems associated with surveillance at the final stages of malaria elimination. Methods Plasmodium vivax samples collected in Tumeremo, Venezuela, between March 2003 and November 2004 were analysed. Since Plasmodium falciparum also circulates in many low endemic areas, P. falciparum samples from the same locality and time period were included for comparison. Plasmodium vivax samples were assayed for an original set of 25 microsatellites and P. falciparum samples were assayed for 12 microsatellites. Results Not all microsatellite loci assayed offered reliable local data. A complex temporal-cluster dynamics is found in both P. vivax and P. falciparum. Such dynamics affect the numbers and the type of microsatellites required for identifying individual parasites or parasite clusters when performing cross-sectional studies. The minimum number of microsatellites required to differentiate circulating P. vivax clusters differs from the minimum number of hyper-variable microsatellites required to distinguish individuals within these clusters. Regardless the extended number of microsatellites used in P. vivax, it was not possible to separate all individual infections. Conclusions Molecular surveillance has great potential; however, it requires preliminary local studies in order to properly interpret the emerging patterns in the context of elimination. Clonal

  16. Locally adaptive document skew detection

    NASA Astrophysics Data System (ADS)

    Sauvola, Jaakko J.; Doermann, David S.; Pietikaeinen, Matti

    1997-04-01

    This paper proposes a new approach to the detection of local orientation and skew in document images. It is based on the observation that there are many documents where a single global estimate of the page skew is not sufficient. These documents require local adaptation to deal robustly with todays complex configurations of components on the page. The approach attempts to identify regions in the image which exhibit locally consistent physical properties and consistent physical properties and consistent orientation. To do this, we rapidly compute a coarse segmentation and delineate regions which differ with respect to layout and/or physical content. Each region is classified as text, graphics, mixed text/graphics, image or background using local features and additional features are extracted to estimate orientation. The local orientation decisions are propagated where appropriate to resolve ambiguity and to produce a global estimate of the skew for the page. The implementation of our algorithms is demonstrated on a set of images which have multiple regions with different orientations.

  17. Malaria in rural Burkina Faso: local illness concepts, patterns of traditional treatment and influence on health-seeking behaviour

    PubMed Central

    Beiersmann, Claudia; Sanou, Aboubakary; Wladarsch, Evelyn; De Allegri, Manuela; Kouyaté, Bocar; Müller, Olaf

    2007-01-01

    Background The literature on health care seeking behaviour in sub-Saharan Africa for children suffering from malaria is quite extensive. This literature, however, is predominately quantitative and, inevitably, fails to explore how the local concepts of illness may affect people's choices. Understanding local concepts of illness and their influence on health care-seeking behaviour can complement existing knowledge and lead to the development of more effective malaria control interventions. Methods In a rural area of Burkina Faso, four local concepts of illness resembling the biomedical picture of malaria were described according to symptoms, aetiology, and treatment. Data were collected through eight focus group discussions, 17 semi-structured interviews with key informants, and through the analysis of 100 verbal autopsy questionnaires of children under-five diagnosed with malaria. Results Sumaya, dusukun yelema, kono, and djoliban were identified as the four main local illness concepts resembling respectively uncomplicated malaria, respiratory distress syndrome, cerebral malaria, and severe anaemia. The local disease categorization was found to affect both treatment and provider choice. While sumaya is usually treated by a mix of traditional and modern methods, dusukun yelema and kono are preferably treated by traditional healers, and djoliban is preferably treated in modern health facilities. Besides the conceptualization of illness, poverty was found to be another important influencing factor of health care-seeking behaviour. Conclusion The findings complement previous evidence on health care-seeking behaviour, by showing how local concepts of illness strongly influence treatment and choice of provider. Local concepts of illness need to be considered when developing specific malaria control programmes. PMID:17686147

  18. Malaria PCR detection in Cambodian low-transmission settings: dried blood spots versus venous blood samples.

    PubMed

    Canier, Lydie; Khim, Nimol; Kim, Saorin; Eam, Rotha; Khean, Chanra; Loch, Kaknika; Ken, Malen; Pannus, Pieter; Bosman, Philippe; Stassijns, Jorgen; Nackers, Fabienne; Alipon, SweetC; Char, Meng Chuor; Chea, Nguon; Etienne, William; De Smet, Martin; Kindermans, Jean-Marie; Ménard, Didier

    2015-03-01

    In the context of malaria elimination, novel strategies for detecting very low malaria parasite densities in asymptomatic individuals are needed. One of the major limitations of the malaria parasite detection methods is the volume of blood samples being analyzed. The objective of the study was to compare the diagnostic accuracy of a malaria polymerase chain reaction assay, from dried blood spots (DBS, 5 μL) and different volumes of venous blood (50 μL, 200 μL, and 1 mL). The limit of detection of the polymerase chain reaction assay, using calibrated Plasmodium falciparum blood dilutions, showed that venous blood samples (50 μL, 200 μL, 1 mL) combined with Qiagen extraction methods gave a similar threshold of 100 parasites/mL, ∼100-fold lower than 5 μL DBS/Instagene method. On a set of 521 field samples, collected in two different transmission areas in northern Cambodia, no significant difference in the proportion of parasite carriers, regardless of the methods used was found. The 5 μL DBS method missed 27% of the samples detected by the 1 mL venous blood method, but most of the missed parasites carriers were infected by Plasmodium vivax (84%). The remaining missed P. falciparum parasite carriers (N = 3) were only detected in high-transmission areas.

  19. Modelling malaria incidence with environmental dependency in a locality of Sudanese savannah area, Mali

    PubMed Central

    Gaudart, Jean; Touré, Ousmane; Dessay, Nadine; Dicko, A lassane; Ranque, Stéphane; Forest, Loic; Demongeot, Jacques; Doumbo, Ogobara K

    2009-01-01

    Background The risk of Plasmodium falciparum infection is variable over space and time and this variability is related to environmental variability. Environmental factors affect the biological cycle of both vector and parasite. Despite this strong relationship, environmental effects have rarely been included in malaria transmission models. Remote sensing data on environment were incorporated into a temporal model of the transmission, to forecast the evolution of malaria epidemiology, in a locality of Sudanese savannah area. Methods A dynamic cohort was constituted in June 1996 and followed up until June 2001 in the locality of Bancoumana, Mali. The 15-day composite vegetation index (NDVI), issued from satellite imagery series (NOAA) from July 1981 to December 2006, was used as remote sensing data. The statistical relationship between NDVI and incidence of P. falciparum infection was assessed by ARIMA analysis. ROC analysis provided an NDVI value for the prediction of an increase in incidence of parasitaemia. Malaria transmission was modelled using an SIRS-type model, adapted to Bancoumana's data. Environmental factors influenced vector mortality and aggressiveness, as well as length of the gonotrophic cycle. NDVI observations from 1981 to 2001 were used for the simulation of the extrinsic variable of a hidden Markov chain model. Observations from 2002 to 2006 served as external validation. Results The seasonal pattern of P. falciparum incidence was significantly explained by NDVI, with a delay of 15 days (p = 0.001). An NDVI threshold of 0.361 (p = 0.007) provided a Diagnostic Odd Ratio (DOR) of 2.64 (CI95% [1.26;5.52]). The deterministic transmission model, with stochastic environmental factor, predicted an endemo-epidemic pattern of malaria infection. The incidences of parasitaemia were adequately modelled, using the observed NDVI as well as the NDVI simulations. Transmission pattern have been modelled and observed values were adequately predicted. The error

  20. Dynamic linear models using the Kalman filter for early detection and early warning of malaria outbreaks

    NASA Astrophysics Data System (ADS)

    Merkord, C. L.; Liu, Y.; DeVos, M.; Wimberly, M. C.

    2015-12-01

    Malaria early detection and early warning systems are important tools for public health decision makers in regions where malaria transmission is seasonal and varies from year to year with fluctuations in rainfall and temperature. Here we present a new data-driven dynamic linear model based on the Kalman filter with time-varying coefficients that are used to identify malaria outbreaks as they occur (early detection) and predict the location and timing of future outbreaks (early warning). We fit linear models of malaria incidence with trend and Fourier form seasonal components using three years of weekly malaria case data from 30 districts in the Amhara Region of Ethiopia. We identified past outbreaks by comparing the modeled prediction envelopes with observed case data. Preliminary results demonstrated the potential for improved accuracy and timeliness over commonly-used methods in which thresholds are based on simpler summary statistics of historical data. Other benefits of the dynamic linear modeling approach include robustness to missing data and the ability to fit models with relatively few years of training data. To predict future outbreaks, we started with the early detection model for each district and added a regression component based on satellite-derived environmental predictor variables including precipitation data from the Tropical Rainfall Measuring Mission (TRMM) and land surface temperature (LST) and spectral indices from the Moderate Resolution Imaging Spectroradiometer (MODIS). We included lagged environmental predictors in the regression component of the model, with lags chosen based on cross-correlation of the one-step-ahead forecast errors from the first model. Our results suggest that predictions of future malaria outbreaks can be improved by incorporating lagged environmental predictors.

  1. Investigation of surface enhanced Raman spectroscopy for hemozoin detection in malaria diagnosis

    NASA Astrophysics Data System (ADS)

    Chen, Keren; Xiong, Aoli; Yuen, Clement; Preiser, Peter; Liu, Quan

    2016-03-01

    We report two methods of surface enhanced Raman spectroscopy (SERS) for hemozoin detection in malaria infected human blood. In the first method, silver nanoparticles were synthesized separately and then mixed with lysed blood; while in the second method, silver nanoparticles were synthesized directly inside the parasites of Plasmodium falciparum.

  2. Photoacoustic detection of hemozoin in human mononuclear cells as an early indicator of malaria infection

    NASA Astrophysics Data System (ADS)

    Custer, Jonathan R.; Kariuki, Michael; Beerntsen, Brenda T.; Viator, John A.

    2010-02-01

    Malaria is a blood borne infection affecting hundreds of millions of people worldwide2. The parasites reproduce within the blood cells, eventually causing their death and lysis. This process releases the parasites into the blood, continuing the cycle of infection. Usually, malaria is diagnosed only after a patient presents symptoms, including high fever, nausea, and, in advanced cases, coma and death. While invading the bloodstream of a host, malaria parasites convert hemoglobin into an insoluble crystal, known as hemozoin. These crystals, approximately several hundred nanometers in size, are contained within red blood cells and white blood cells that ingest free hemozoin in the blood. Thus, infected red blood cells and white blood cells contain a unique optical absorber that can be detected in blood samples using static photoacoustic detection methods. We separated the white blood cells from malaria infected blood and tested it in a photoacoustic set up using a tunable laser system consisting of an optical parametric oscillator pumped by an Nd:YAG laser with pulse duration of 5 ns. Our threshold of detection was 10 infected white blood cells per microliter, which is more sensitive than current diagnosis methods using microscopic analysis of blood.

  3. Sensitive DNA detection and SNP discrimination using ultrabright SERS nanorattles and magnetic beads for malaria diagnostics.

    PubMed

    Ngo, Hoan T; Gandra, Naveen; Fales, Andrew M; Taylor, Steve M; Vo-Dinh, Tuan

    2016-07-15

    One of the major obstacles to implement nucleic acid-based molecular diagnostics at the point-of-care (POC) and in resource-limited settings is the lack of sensitive and practical DNA detection methods that can be seamlessly integrated into portable platforms. Herein we present a sensitive yet simple DNA detection method using a surface-enhanced Raman scattering (SERS) nanoplatform: the ultrabright SERS nanorattle. The method, referred to as the nanorattle-based method, involves sandwich hybridization of magnetic beads that are loaded with capture probes, target sequences, and ultrabright SERS nanorattles that are loaded with reporter probes. Upon hybridization, a magnet was applied to concentrate the hybridization sandwiches at a detection spot for SERS measurements. The ultrabright SERS nanorattles, composed of a core and a shell with resonance Raman reporters loaded in the gap space between the core and the shell, serve as SERS tags for signal detection. Using this method, a specific DNA sequence of the malaria parasite Plasmodium falciparum could be detected with a detection limit of approximately 100 attomoles. Single nucleotide polymorphism (SNP) discrimination of wild type malaria DNA and mutant malaria DNA, which confers resistance to artemisinin drugs, was also demonstrated. These test models demonstrate the molecular diagnostic potential of the nanorattle-based method to both detect and genotype infectious pathogens. Furthermore, the method's simplicity makes it a suitable candidate for integration into portable platforms for POC and in resource-limited settings applications.

  4. Malaria Vectors in Ecologically Heterogeneous Localities of the Colombian Pacific Region

    PubMed Central

    Naranjo-Díaz, Nelson; Altamiranda, Mariano; Luckhart, Shirley; Conn, Jan E.; Correa, Margarita M.

    2014-01-01

    The Colombian Pacific region is second nationally in number of malaria cases reported. This zone presents great ecological heterogeneity and Anopheles species diversity. However, little is known about the current spatial and temporal distribution of vector species. This study, conducted in three ecologically different localities of the Pacific region, aimed to evaluate the composition and distribution of Anopheles species and characterize transmission intensity. A total of 4,016 Anopheles mosquitoes were collected representing seven species. The composition and dominant species differed in each locality. Three species were infected with malaria parasites: Anopheles darlingi and An. calderoni were infected with Plasmodium falciparum and An. nuneztovari with Plasmodium vivax VK210 and VK247. Annual EIRs varied from 3.5–7.2 infective bites per year. These results confirm the importance of the primary vector An. nuneztovari in areas disturbed by human interventions, of An. darlingi in deforested margins of humid tropical rainforest and An. albimanus and the suspected vector An. calderoni in areas impacted by urbanization and large-scale palm oil agriculture close to the coast. This constitutes the first report in the Colombia Pacific region of naturally infected An. darlingi, and in Colombia of naturally infected An. calderoni. Further studies should evaluate the epidemiological importance of An. calderoni in the Pacific region. PMID:25090233

  5. Comparison of blood smear, antigen detection, and nested-PCR methods for screening refugees from regions where malaria is endemic after a malaria outbreak in Quebec, Canada.

    PubMed

    Ndao, Momar; Bandyayera, Etienne; Kokoskin, Evelyne; Gyorkos, Theresa W; MacLean, J Dick; Ward, Brian J

    2004-06-01

    The importation of malaria into a region where it is not endemic raises many concerns, including the timely delivery of appropriate care, safety of the blood supply, and the risk of autochthonous transmission. There is presently no consensus on the best way to screen mobile populations for malaria. Between August 2000 and March 2001, 535 refugees arrived in Quebec, Canada, from Tanzanian camps. Within 4 weeks of resettlement of the first group of 224, the McGill University Centre for Tropical Diseases noted an outbreak of malaria across the province (15 cases over a 3-week period). This group (group 1) was traced and screened for malaria between 3 and 4 months after arrival in Canada. Subsequent groups of 106 and 205 refugees were screened immediately upon arrival in Canada (group 2) and immediately prior to their departure from refugee camps (group 3), respectively. A single EDTA-blood sample was obtained from 521 refugees for testing by thick and thin blood smears (groups 1 and 2), antigen detection (ICT Malaria Pf and OptiMAL; group 1 only), and nested PCR (all groups). Overall, 98 of 521 refugees were found to be infected (18.8%). The vast majority of infections (81 of 98) were caused by Plasmodium falciparum alone. Using PCR as the "gold standard," both microscopy (sensitivity, 50%; specificity, 100%) and antigen detection (ICT sensitivity, 37.5%; ICT specificity, 100%; OptiMAL sensitivity, 29.1%; OptiMAL specificity, 95.6%) performed poorly. None of the PCR-positive subjects were symptomatic at the time of testing, and only two had recently had symptoms compatible with malaria (with or without diagnosis and treatment). Active surveillance of migrants from regions of intense malaria transmission can reduce the risk of morbidity in the migrant population and mitigate against transmission to the host population. Our data demonstrate that PCR is, by far, the most powerful tool for such surveillance.

  6. Mobile phone imaging and cloud-based analysis for standardized malaria detection and reporting

    NASA Astrophysics Data System (ADS)

    Scherr, Thomas F.; Gupta, Sparsh; Wright, David W.; Haselton, Frederick R.

    2016-06-01

    Rapid diagnostic tests (RDTs) have been widely deployed in low-resource settings. These tests are typically read by visual inspection, and accurate record keeping and data aggregation remains a substantial challenge. A successful malaria elimination campaign will require new strategies that maximize the sensitivity of RDTs, reduce user error, and integrate results reporting tools. In this report, an unmodified mobile phone was used to photograph RDTs, which were subsequently uploaded into a globally accessible database, REDCap, and then analyzed three ways: with an automated image processing program, visual inspection, and a commercial lateral flow reader. The mobile phone image processing detected 20.6 malaria parasites/microliter of blood, compared to the commercial lateral flow reader which detected 64.4 parasites/microliter. Experienced observers visually identified positive malaria cases at 12.5 parasites/microliter, but encountered reporting errors and false negatives. Visual interpretation by inexperienced users resulted in only an 80.2% true negative rate, with substantial disagreement in the lower parasitemia range. We have demonstrated that combining a globally accessible database, such as REDCap, with mobile phone based imaging of RDTs provides objective, secure, automated, data collection and result reporting. This simple combination of existing technologies would appear to be an attractive tool for malaria elimination campaigns.

  7. Mobile phone imaging and cloud-based analysis for standardized malaria detection and reporting

    PubMed Central

    Scherr, Thomas F.; Gupta, Sparsh; Wright, David W.; Haselton, Frederick R.

    2016-01-01

    Rapid diagnostic tests (RDTs) have been widely deployed in low-resource settings. These tests are typically read by visual inspection, and accurate record keeping and data aggregation remains a substantial challenge. A successful malaria elimination campaign will require new strategies that maximize the sensitivity of RDTs, reduce user error, and integrate results reporting tools. In this report, an unmodified mobile phone was used to photograph RDTs, which were subsequently uploaded into a globally accessible database, REDCap, and then analyzed three ways: with an automated image processing program, visual inspection, and a commercial lateral flow reader. The mobile phone image processing detected 20.6 malaria parasites/microliter of blood, compared to the commercial lateral flow reader which detected 64.4 parasites/microliter. Experienced observers visually identified positive malaria cases at 12.5 parasites/microliter, but encountered reporting errors and false negatives. Visual interpretation by inexperienced users resulted in only an 80.2% true negative rate, with substantial disagreement in the lower parasitemia range. We have demonstrated that combining a globally accessible database, such as REDCap, with mobile phone based imaging of RDTs provides objective, secure, automated, data collection and result reporting. This simple combination of existing technologies would appear to be an attractive tool for malaria elimination campaigns. PMID:27345590

  8. A Systems Thinking Framework for Assessing and Addressing Malaria Locally: An Alternative to the Globalization of Anti-Malaria Policies

    ERIC Educational Resources Information Center

    Willis, Derek W.

    2010-01-01

    This dissertation analyzes a decision system that was used in the early 1900s in the Federated Malay States (FMS) by Malcolm Watson in order to make anti-malaria program recommendations to decision makers in a wide range of ecological settings. Watson's recommendations to decision makers throughout the FMS led to a dramatic suppression of malaria…

  9. Polymerase chain reaction detection of human host preference and Plasmodium parasite infections in field collected potential malaria vectors.

    PubMed

    Dhiman, Sunil; Bhola, Rakesh Kumar; Goswami, Diganta; Rabha, Bipul; Kumar, Dinesh; Baruah, Indra; Singh, Lokendra

    2012-07-01

    This study was carried out to determine the human host preference and presence of Plasmodium parasite in field collected Anopheles mosquitoes among four villages around a military cantonment located in malaria endemic Sonitpur district of Assam, India. Encountered malaria vector mosquitoes were identified and tested for host preference and Plasmodium presence using PCR method. Human host preference was detected using simple PCR, whereas vectorial status for Plasmodium parasite was confirmed using first round PCR with genus specific primers and thereafter nested PCR with three Plasmodium species specific primers. Out of 1874 blood fed vector mosquitoes collected, 187 (10%) were processed for PCR, which revealed that 40·6% had fed on human blood; 9·2% of human blood fed mosquito were harbouring Plasmodium parasites, 71·4% of which were confirmed to Plasmodium falciparum. In addition to An. minimus, An. annularis and An. culicifacies were also found positive for malaria parasites. The present study exhibits the human feeding tendency of Anopheles vectors highlighting their malaria parasite transmission potential. The present study may serve as a model for understanding the human host preference of malaria vectors and detection of malaria parasite inside the anopheline vector mosquitoes in order to update their vectorial status for estimating the possible role of these mosquitoes in malaria transmission. The study has used PCR method and suggests that PCR-based method should be used in this entire malarious region to correctly report the vectorial position of different malaria vectors.

  10. Multiplexed, Patterned-Paper Immunoassay for Detection of Malaria and Dengue Fever.

    PubMed

    Deraney, Rachel N; Mace, Charles R; Rolland, Jason P; Schonhorn, Jeremy E

    2016-06-21

    Multiplex assays detect the presence of more than one analyte in a sample. For diagnostic applications, multiplexed tests save healthcare providers time and resources by performing many assays in parallel, minimizing the amount of sample needed and improving the quality of information acquired regarding the health status of a patient. These advantages are of particular importance for those diseases that present with general, overlapping symptoms, which makes presumptive treatments inaccurate and may put the patient at risk. For example, malaria and dengue fever are febrile illnesses transmitted through mosquito bites, and these common features make it difficult to obtain an accurate diagnosis by symptoms alone. In this manuscript, we describe the development of a multiplexed, patterned paper immunoassay for the detection of biomarkers of malaria and dengue fever: malaria HRP2, malaria pLDH, and dengue NS1 type 2. In areas coendemic for malaria and dengue fever, this assay could be used as a rapid, point-of-care diagnostic to determine the cause of a fever of unknown origin. The reagents required for each paper-based immunoassay are separated spatially within a three-dimensional device architecture, which allows the experimental conditions to be adjusted independently for each assay. We demonstrate the analytical performances of paper-based assays for each biomarker and we show that there is no significant difference in performance between the multiplexed immunoassay and those immunoassays performed in singleplex. Additionally, we spiked individual analytes into lysed human blood to demonstrate specificity in a clinically relevant sample matrix. Our results suggest multiplex paper-based devices can be an essential component of diagnostic assays used at the point-of-care.

  11. [The epidemic situation with malaria in Turkmenistan].

    PubMed

    Amangel'diev, K A; Morozova, K V; Medalieva, D O

    2000-01-01

    As a result of comprehensive research on the causative agents and vectors of malaria and wide use of synthetic antimalarials and highly effective residual insecticides, endemic malaria was eliminated in Turkmenistan by 1960. During the period 1965-1980, 23 local cases of malaria were recorded in Turkmenistan. These local cases were confined to the regions of Mary and Akhal, on the borders of neighbouring countries. In 1998 the epidemiological situation in the country worsened and local transmission of infection resumed. During the year the number of cases recorded was 137:134 being a first diagnosis of the disease and three being relapsed cases. In comparison with 1997, the previous year, incidence was up by 123 cases (a 9.7-fold increase), while the incidence of imported cases of malaria went up by 11 (a 2.2-fold increase), principally in Dashkhovuz and Lebar regions, being brought in from malaria foci in Gushgin district, Turkey, Azerbaijan and Tadjikistan. Local transmission of malaria went up by 111 cases (a 27.7 fold increase); 108 cases were recorded in Gushgin district, Mary region. The first case of malaria in Gushkin district was detected in June 1998. At that time there were five active foci. The approximate number of inhabitants in the active focus area was 10,000. The appearance of local malaria in border districts was caused by the periodic influx of infected mosquitos from neighbouring countries (Afghanistan).

  12. PCR detection of malaria parasites in desiccated Anopheles mosquitoes is uninhibited by storage time and temperature

    PubMed Central

    2012-01-01

    Background Reliable methods to preserve mosquito vectors for malaria studies are necessary for detecting Plasmodium parasites. In field settings, however, maintaining a cold chain of storage from the time of collection until laboratory processing, or accessing other reliable means of sample preservation is often logistically impractical or cost prohibitive. As the Plasmodium infection rate of Anopheles mosquitoes is a central component of the entomological inoculation rate and other indicators of transmission intensity, storage conditions that affect pathogen detection may bias malaria surveillance indicators. This study investigated the effect of storage time and temperature on the ability to detect Plasmodium parasites in desiccated Anopheles mosquitoes by real-time polymerase chain reaction (PCR). Methods Laboratory-infected Anopheles stephensi mosquitoes were chloroform-killed and stored over desiccant for 0, 1, 3, and 6 months while being held at four different temperatures: 28, 37, -20 and -80°C. The detection of Plasmodium DNA was evaluated by real-time PCR amplification of a 111 base pair region of block 4 of the merozoite surface protein. Results Varying the storage time and temperature of desiccated mosquitoes did not impact the sensitivity of parasite detection. A two-way factorial analysis of variance suggested that storage time and temperature were not associated with a loss in the ability to detect parasites. Storage of samples at 28°C resulted in a significant increase in the ability to detect parasite DNA, though no other positive associations were observed between the experimental storage treatments and PCR amplification. Conclusions Cold chain maintenance of desiccated mosquito samples is not necessary for real-time PCR detection of parasite DNA. Though field-collected mosquitoes may be subjected to variable conditions prior to molecular processing, the storage of samples over an inexpensive and logistically accessible desiccant will likely

  13. Usefulness of quantitative buffy coat blood parasite detection system in diagnosis of malaria.

    PubMed

    Pinto, M J; Rodrigues, S R; Desouza, R; Verenkar, M P

    2001-01-01

    A rapid test for diagnosis of malaria based on acridine orange staining of centrifuged blood samples in a microhematocrit tube (QBC) was compared with thick and thin peripheral blood smears in 2274 samples. Malaria was diagnosed in 239 (10.5%) patients by Leishman's staining technique and QBC method. The QBC method allowed detection of an additional 89 (3.9%) cases. Thus the prevalence rate of malaria during the study was 14.4%. In 1946 patients who were negative by the QBC technique, the Leishman's stained smears did not provide any help in malaria diagnosis. Analysis of the relative quantity of parasites in the specimens, in the QBC method, revealed that 80 out of 89 QBC positive but smear negative cases, had a very low parasite number (less than 10 parasites per QBC field). Although QBC method was superior to the smear for malarial parasite detection, species identification was not possible in 26 (7.9%) cases by this technique. In 95.7% (n = 314) QBC positive cases, the buffy coat in the QBC tube appeared pigmented (gray to black). The colour of the buffy coat was therefore considered by us as a predictor of positivity and could be taken as an indicator for a careful and more prolonged search for the parasites. Thus, the QBC technique has its advantages in terms of speed, sensitivity and ease, especially in an endemic area as ours, where the level of parasitaemia is low and more than 70 to 80 smears need to be examined per day. However, the age old Romanowsky stains still appear superior for species identification.

  14. Comparison of two real-time PCR assays for the detection of malaria parasites from hemolytic blood samples - Short communication.

    PubMed

    Hagen, Ralf Matthias; Hinz, Rebecca; Tannich, Egbert; Frickmann, Hagen

    2015-06-01

    We compared the performance of an in-house and a commercial malaria polymerase chain reaction (PCR) assay using freeze-thawed hemolytic blood samples. A total of 116 freeze-thawed ethylenediamine tetraacetic acid (EDTA) blood samples of patients with suspicion of malaria were analyzed by an in-house as well as by a commercially available real-time PCR. Concordant malaria negative PCR results were reported for 39 samples and malaria-positive PCR results for 67 samples. The in-house assay further detected one case of Plasmodium falciparum infection, which was negative in the commercial assay as well as five cases of P. falciparum malaria and three cases of Plasmodium vivax malaria, which showed sample inhibition in the commercial assay. The commercial malaria assay was positive in spite of a negative in-house PCR result in one case. In all concordant results, cycle threshold values of P. falciparum-positive samples were lower in the commercial PCR than in the in-house assay. Although Ct values of the commercial PCR kit suggest higher sensitivity in case of concordant results, it is prone to inhibition if it is applied to hemolytic freeze-thawed blood samples. The number of misidentifications was, however, identical for both real-time PCR assays.

  15. Evaluating local vegetation cover as a risk factor for malaria transmission: a new analytical approach using ImageJ

    PubMed Central

    2014-01-01

    Background In places where malaria transmission is unstable or is transmitted under hypoendemic conditions, there are periods where limited foci of cases still occur and people become infected. These residual “hot spots” are likely reservoirs of the parasite population and so are fundamental to the seasonal spread and decline of malaria. It is, therefore, important to understand the ecological conditions that permit vector mosquitoes to survive and forage in these specific areas. Features such as local waterways and vegetation, as well as local ecology, particularly nocturnal temperature, humidity, and vegetative sustainability, are important for modeling local mosquito behavior. Vegetation around a homestead likely provides refuge for outdoor resting of these insects and may be a risk factor for malaria transmission. Analysis of this vegetation can be done using satellite information and mapping programs, such as Google Earth, but manual quantification is difficult and can be tedious and subjective. A more objective method is required. Methods Vegetation cover in the environment is reasonably static, particularly in and around homesteads. In order to evaluate and enumerate such information, ImageJ, an image processing software, was used to analyse Google Earth satellite imagery. The number of plants, total amount of vegetation around a homestead and its percentage of the total area were calculated and related to homesteads where cases of malaria were recorded. Results Preliminary results were obtained from a series of field trials carried out in South East Zambia in the Choma and Namwala districts from a base at the Macha District Hospital. Conclusions This technique is objective, clear and simple to manipulate and has potential application to determine the role that vegetation proximal to houses may play in affecting mosquito behaviour, foraging and subsequent malaria incidence. PMID:24620929

  16. Prevalence of PCR detectable malaria infection among febrile patients with a negative Plasmodium falciparum specific rapid diagnostic test in Zanzibar.

    PubMed

    Baltzell, Kimberly A; Shakely, Deler; Hsiang, Michelle; Kemere, Jordan; Ali, Abdullah Suleiman; Björkman, Anders; Mårtensson, Andreas; Omar, Rahila; Elfving, Kristina; Msellem, Mwinyi; Aydin-Schmidt, Berit; Rosenthal, Philip J; Greenhouse, Bryan

    2013-02-01

    We screened for malaria in 594 blood samples from febrile patients who tested negative by a Plasmodium falciparum-specific histidine-rich protein-2-based rapid diagnostic test at 12 health facilities in Zanzibar districts North A and Micheweni, from May to August 2010. Screening was with microscopy, polymerase chain reaction (PCR) targeting the cytochrome b gene (cytbPCR) of the four major human malaria species, and quantitative PCR (qPCR). The prevalence of cytbPCR-detectable malaria infection was 2% (12 of 594), including 8 P. falciparum, 3 Plasmodium malariae, and 1 Plasmodium vivax infections. Microscopy identified 4 of 8 P. falciparum infections. Parasite density as estimated by microscopy or qPCR was > 4,000 parasites/μL in 5 of 8 cytbPCR-detectable P. falciparum infections. The infections that were missed by the rapid diagnostic test represent a particular challenge in malaria elimination settings and highlight the need for more sensitive point-of-care diagnostic tools to improve case detection of all human malaria species in febrile patients.

  17. Reproductive isolation and local adaptation quantified for a chromosome inversion in a malaria mosquito.

    PubMed

    Ayala, Diego; Guerrero, Rafael F; Kirkpatrick, Mark

    2013-04-01

    Chromosome inversions have long been thought to be involved in speciation and local adaptation. We have little quantitative information, however, about the effects that inversion polymorphisms have on reproductive isolation and viability. Here we provide the first estimates from any organism for the total amount of reproductive isolation associated with an inversion segregating in natural populations. We sampled chromosomes from 751 mosquitoes of the malaria vector Anopheles funestus along a 1421 km transect in Cameroon that traverses savannah, highland, and rainforest ecological zones. We then developed a series of population genetic models that account for selection, migration, and assortative mating, and fit the models to the data using likelihood. Results from the best-fit models suggest there is strong local adaptation, with relative viabilities of homozygotes ranging from 25% to 130% compared to heterozygotes. Viabilities vary qualitatively between regions: the inversion is underdominant in the savannah, whereas in the highlands it is overdominant. The inversion is also implicated in strong assortative mating. In the savannah, the two homozygote forms show 92% reproductive isolation, suggesting that this one inversion can generate most of the genetic barriers needed for speciation.

  18. Detection and localization of satellites

    NASA Astrophysics Data System (ADS)

    Bautista Aranda, Manuel

    The surveillance of orbital space is conducted in order to (1) detect military activities, (2) keep a tally of active and 'dead' satellites, launch vehicle upper stages, explosion debris, etc., and (3) prevent collisions with active satellites, as well as anticipate the exact timing of satellite reentries. An account is presently given of the complex system of optical- and radar-sensor space surveillance conducted by agencies of the U.S. government.

  19. Development and clinical performance of high throughput loop-mediated isothermal amplification for detection of malaria

    PubMed Central

    Perera, Rushini S.; Ding, Xavier C.; Tully, Frank; Oliver, James; Bright, Nigel; Bell, David; Chiodini, Peter L.; Gonzalez, Iveth J.; Polley, Spencer D.

    2017-01-01

    Background Accurate and efficient detection of sub-microscopic malaria infections is crucial for enabling rapid treatment and interruption of transmission. Commercially available malaria LAMP kits have excellent diagnostic performance, though throughput is limited by the need to prepare samples individually. Here, we evaluate the clinical performance of a newly developed high throughput (HTP) sample processing system for use in conjunction with the Eiken malaria LAMP kit. Methods The HTP system utilised dried blood spots (DBS) and liquid whole blood (WB), with parallel sample processing of 94 samples per run. The system was evaluated using 699 samples of known infection status pre-determined by gold standard nested PCR. Results The sensitivity and specificity of WB-HTP-LAMP was 98.6% (95% CI, 95.7–100), and 99.7% (95% CI, 99.2–100); sensitivity of DBS-HTP-LAMP was 97.1% (95% CI, 93.1–100), and specificity 100% against PCR. At parasite densities greater or equal to 2 parasites/μL, WB and DBS HTP-LAMP showed 100% sensitivity and specificity against PCR. At densities less than 2 p/μL, WB-HTP-LAMP sensitivity was 88.9% (95% CI, 77.1–100) and specificity was 99.7% (95% CI, 99.2–100); sensitivity and specificity of DBS-HTP-LAMP was 77.8% (95% CI, 54.3–99.5) and 100% respectively. Conclusions The HTP-LAMP system is a highly sensitive diagnostic test, with the potential to allow large scale population screening in malaria elimination campaigns. PMID:28166235

  20. Violation of local realism versus detection efficiency

    SciTech Connect

    Massar, Serge; Pironio, Stefano

    2003-12-01

    We put bounds on the minimum detection efficiency necessary to violate local realism in Bell experiments. These bounds depend on simple parameters like the number of measurement settings or the dimensionality of the entangled quantum state. We derive them by constructing explicit local hidden variable models which reproduce the quantum correlations for sufficiently small detectors efficiency.

  1. Low autochtonous urban malaria in Antananarivo (Madagascar)

    PubMed Central

    Rabarijaona, Léon Paul; Ariey, Frédéric; Matra, Robert; Cot, Sylvie; Raharimalala, Andrianavalona Lucie; Ranaivo, Louise Henriette; Le Bras, Jacques; Robert, Vincent; Randrianarivelojosia, Milijaona

    2006-01-01

    Background The study of urban malaria is an area undergoing rapid expansion, after many years of neglect. The problem of over-diagnosis of malaria, especially in low transmission settings including urban areas, is also receiving deserved attention. The primary objective of the present study was to assess the frequency of malaria among febrile outpatients seen in private and public primary care facilities of Antananarivo. The second aim was to determine, among the diagnosed malaria cases, the contribution of autochthonous urban malaria. Methods Two cross-sectional surveys in 43 health centres in Antananarivo in February 2003 (rainy season) and in July 2003 (dry season) were conducted. Consenting clinically suspected malaria patients with fever or history of fever in the past 48 hours were included. Malaria rapid diagnostic tests and microscopy were used to diagnose malaria. Basic information was collected from patients to try to identify the origin of the infection: autochthonous or introduced. Results In February, among 771 patients, 15 (1.9%) positive cases were detected. Three malaria parasites were implicated: Plasmodium. falciparum (n = 12), Plasmodium vivax (n = 2) and Plasmodium. ovale (n = 1). Only two cases, both P. falciparum, were likely to have been autochthonous (0.26%). In July, among 739 blood smears examined, 11 (1.5%) were positive: P. falciparum (n = 9) and P. vivax (n = 2). Three cases of P. falciparum malaria were considered to be of local origin (0.4%). Conclusion This study demonstrates that malaria cases among febrile episodes are low in Antananarivo and autochthonous malaria cases exist but are rare. PMID:16573843

  2. Sample-ready multiplex qPCR assay for detection of malaria

    PubMed Central

    2014-01-01

    Background Microscopy and antigen detecting rapid diagnostic tests are the diagnostic tests of choice in management of clinical malaria. However, due to their limitations, the need to utilize more sensitive methods such as real-time PCR (qPCR) is evident as more studies are now utilizing molecular methods in detection of malaria. Some of the challenges that continue to limit the widespread utilization of qPCR include lack of assay standardization, assay variability, risk of contamination, and the need for cold-chain. Lyophilization of molecular assays can overcome some of these limitations and potentially enable widespread qPCR utilization. Methods A recently published multiplex malaria qPCR assay was lyophilized by freezing drying into Sample-Ready™ format (MMSR). MMSR assay contained all the required reagents for qPCR including primers and probes, requiring only the addition of water and sample to perform qPCR. The performance of the MMSR assay was compared to the non-freeze dried, “wet” assay. Stability studies were done by maintaining the MMSR assays at four different ambient temperatures of 4°C, room temperature (RT), 37°C and 42°C over a period of 42 days, tested at seven-day intervals. Plasmodium falciparum and Plasmodium vivax DNAs were used for analysis of the MMSR assay either as single or mixed parasites, at two different concentrations. The CT values and the standard deviations (SD) were used in the analysis of the assay performance. Results The limit of detection for the MMSR assay was 0.244 parasites/μL for Plasmodium spp. (PLU) and P. falciparum (FAL) assay targets compared to “wet” assay which was 0.39 and 3.13 parasites/μL for PLU and FAL assay targets, respectively. The MMSR assay performed with high efficiencies similar to those of the “wet” assay and was stable at 37°C for 42 days, with estimated shelf-life of 5 months. When used to analyse field clinical samples, MMSR assay performed with 100% sensitivity and specificity

  3. Molecular Detection of Plasmodium malariae/Plasmodium brasilianum in Non-Human Primates in Captivity in Costa Rica

    PubMed Central

    Fuentes-Ramírez, Alicia; Jiménez-Soto, Mauricio; Castro, Ruth; Romero-Zuñiga, Juan José

    2017-01-01

    One hundred and fifty-two blood samples of non-human primates of thirteen rescue centers in Costa Rica were analyzed to determine the presence of species of Plasmodium using thick blood smears, semi-nested multiplex polymerase chain reaction (SnM-PCR) for species differentiation, cloning and sequencing for confirmation. Using thick blood smears, two samples were determined to contain the Plasmodium malariae parasite, with SnM-PCR, a total of five (3.3%) samples were positive to P. malariae, cloning and sequencing confirmed both smear samples as P. malariae. One sample amplified a larger and conserved region of 18S rDNA for the genus Plasmodium and sequencing confirmed the results obtained microscopically and through SnM-PCR tests. Sequencing and construction of a phylogenetic tree of this sample revealed that the P. malariae/P. brasilianum parasite (GenBank KU999995) found in a howler monkey (Alouatta palliata) is identical to that recently reported in humans in Costa Rica. The SnM-PCR detected P. malariae/P. brasilianum parasite in different non-human primate species in captivity and in various regions of the southern Atlantic and Pacific coast of Costa Rica. The similarity of the sequences of parasites found in humans and a monkey suggests that monkeys may be acting as reservoirs of P.malariae/P. brasilianum, for which reason it is important, to include them in control and eradication programs. PMID:28125696

  4. Molecular Detection of Plasmodium malariae/Plasmodium brasilianum in Non-Human Primates in Captivity in Costa Rica.

    PubMed

    Fuentes-Ramírez, Alicia; Jiménez-Soto, Mauricio; Castro, Ruth; Romero-Zuñiga, Juan José; Dolz, Gaby

    2017-01-01

    One hundred and fifty-two blood samples of non-human primates of thirteen rescue centers in Costa Rica were analyzed to determine the presence of species of Plasmodium using thick blood smears, semi-nested multiplex polymerase chain reaction (SnM-PCR) for species differentiation, cloning and sequencing for confirmation. Using thick blood smears, two samples were determined to contain the Plasmodium malariae parasite, with SnM-PCR, a total of five (3.3%) samples were positive to P. malariae, cloning and sequencing confirmed both smear samples as P. malariae. One sample amplified a larger and conserved region of 18S rDNA for the genus Plasmodium and sequencing confirmed the results obtained microscopically and through SnM-PCR tests. Sequencing and construction of a phylogenetic tree of this sample revealed that the P. malariae/P. brasilianum parasite (GenBank KU999995) found in a howler monkey (Alouatta palliata) is identical to that recently reported in humans in Costa Rica. The SnM-PCR detected P. malariae/P. brasilianum parasite in different non-human primate species in captivity and in various regions of the southern Atlantic and Pacific coast of Costa Rica. The similarity of the sequences of parasites found in humans and a monkey suggests that monkeys may be acting as reservoirs of P.malariae/P. brasilianum, for which reason it is important, to include them in control and eradication programs.

  5. A local space–time kriging approach applied to a national outpatient malaria data set

    PubMed Central

    Gething, P.W.; Atkinson, P.M.; Noor, A.M.; Gikandi, P.W.; Hay, S.I.; Nixon, M.S.

    2007-01-01

    Increases in the availability of reliable health data are widely recognised as essential for efforts to strengthen health-care systems in resource-poor settings worldwide. Effective health-system planning requires comprehensive and up-to-date information on a range of health metrics and this requirement is generally addressed by a Health Management Information System (HMIS) that coordinates the routine collection of data at individual health facilities and their compilation into national databases. In many resource-poor settings, these systems are inadequate and national databases often contain only a small proportion of the expected records. In this paper, we take an important health metric in Kenya (the proportion of outpatient treatments for malaria (MP)) from the national HMIS database and predict the values of MP at facilities where monthly records are missing. The available MP data were densely distributed across a spatiotemporal domain and displayed second-order heterogeneity. We used three different kriging methodologies to make cross-validation predictions of MP in order to test the effect on prediction accuracy of (a) the extension of a spatial-only to a space–time prediction approach, and (b) the replacement of a globally stationary with a locally varying random function model. Space–time kriging was found to produce predictions with 98.4% less mean bias and 14.8% smaller mean imprecision than conventional spatial-only kriging. A modification of space–time kriging that allowed space–time variograms to be recalculated for every prediction location within a spatially local neighbourhood resulted in a larger decrease in mean imprecision over ordinary kriging (18.3%) although the mean bias was reduced less (87.5%). PMID:19424510

  6. Can urine dipstick tests detect renal impairment in Plasmodium falciparum malaria in a rural setup?

    PubMed

    Pati, Sudhanshu S; Mishra, Saroj K

    2010-04-01

    Renal impairment in falciparum malaria leads to poor prognosis. Serum creatinine is the mainstay of diagnosis. However, the serum creatinine concentration is only observed when the glomerular filtration rate falls below 50%. We evaluated the use of the urine dipstick method to predict renal impairment in 77 patients. Twenty-three (29.8%) had haematuria and 52 (67.5%) had urinary protein > or = 300 mg/L. Renal impairment (plasma creatinine > or = 1.2 mg/dL) was observed in 17 patients. The sensitivity and specificity of haematuria in the detection of renal impairment was 94.1% and 90.8%, but for proteinuria it was 88.2% and 62.7%, respectively. There was a positive correlation of plasma urea and creatinine with haematuria (r = 0.56, P < 0.001; r = 0.46, P < 0.01) but not with proteinuria. The detection of haematuria using a dipstick seems to be a highly specific and sensitive method of observing renal impairment in malaria. This is probably the first study which utilizes a commonly available tool that can be easily adopted for early recognition in rural areas.

  7. Expression, characterization, and cellular localization of knowpains, papain-like cysteine proteases of the Plasmodium knowlesi malaria parasite.

    PubMed

    Prasad, Rajesh; Atul; Soni, Awakash; Puri, Sunil Kumar; Sijwali, Puran Singh

    2012-01-01

    Papain-like cysteine proteases of malaria parasites degrade haemoglobin in an acidic food vacuole to provide amino acids for intraerythrocytic parasites. These proteases are potential drug targets because their inhibitors block parasite development, and efforts are underway to develop chemotherapeutic inhibitors of these proteases as the treatments for malaria. Plasmodium knowlesi has recently been shown to be an important human pathogen in parts of Asia. We report expression and characterization of three P. knowlesi papain-like proteases, termed knowpains (KP2-4). Recombinant knowpains were produced using a bacterial expression system, and tested for various biochemical properties. Antibodies against recombinant knowpains were generated and used to determine their cellular localization in parasites. Inhibitory effects of the cysteine protease inhibitor E64 were assessed on P. knowlesi culture to validate drug target potential of knowpains. All three knowpains were present in the food vacuole, active in acidic pH, and capable of degrading haemoglobin at the food vacuolar pH (≈5.5), suggesting roles in haemoglobin degradation. The proteases showed absolute (KP2 and KP3) to moderate (KP4) preference for peptide substrates containing leucine at the P2 position; KP4 preferred arginine at the P2 position. While the three knowpains appear to have redundant roles in haemoglobin degradation, KP4 may also have a role in degradation of erythrocyte cytoskeleton during merozoite egress, as it displayed broad substrate specificity and was primarily localized at the parasite periphery. Importantly, E64 blocked erythrocytic development of P. knowlesi, with enlargement of food vacuoles, indicating inhibition of haemoglobin hydrolysis and supporting the potential for inhibition of knowpains as a strategy for the treatment of malaria. Functional expression and characterization of knowpains should enable simultaneous screening of available cysteine protease inhibitor libraries

  8. Efficiency of Nested-PCR in Detecting Asymptomatic Cases toward Malaria Elimination Program in an Endemic Area of Iran

    PubMed Central

    TURKI, Habibollah; RAEISI, Ahmad; MALEKZADEH, Kianoosh; GHANBARNEJAD, Amin; ZOGHI, Samaneh; YERYAN, Masoud; ABEDI NEJAD, Masoumeh; MOHSENI, Fatemeh; SHEKARI, Mohammad

    2015-01-01

    Background: The aim of this study was to detect low parasite and asymptomatic malaria infections by means of three malaria diagnostic tests, in a low transmission region of Minab district, Hormozgan Province, southern Iran. Methods: Blood samples of 200 healthy volunteers from Bagh-e-Malek area were evaluated using microscopic, rapid diagnostic tests (RDT) and nested-PCR to inspect malaria parasite. Results: The results showed no Plasmodium parasite in subjects by means of microscopy and RDT. However, 3 P. vivax positive samples (1.5%) were discovered by Nested-PCR while microscopy and RDT missed the cases. Conclusion: Microscopy as the gold standard method and RDT correctly identified 98.5% of cases, and molecular analysis is sensitive and reliable, especially in the detection of “asymptomatic” infections for active case surveillance. Regarding the existence of asymptomatic malaria in endemic area of Hormozgan, Iran, nested-PCR could be considered as a sensitive tool to interrupt malaria transmission in the country, beside the microscopic and RDT methods. PMID:25904944

  9. Adult and child malaria mortality in India

    PubMed Central

    Dhingra, Neeraj; Jha, Prabhat; Sharma, Vinod P; Cohen, Alan A; Jotkar, Raju M; Rodriguez, Peter S; Bassani, Diego G; Suraweera, Wilson; Laxminaryan, Ramanan; Peto, Richard

    2010-01-01

    Summary Background Malaria, a non-fatal disease if detected promptly and treated properly, still causes many deaths in malaria-endemic countries with limited healthcare facilities. National malaria mortality rates are, however, particularly difficult to assess reliably in such countries, as any fevers reliably diagnosed as malaria are likely therefore to be cured. Hence, most malaria deaths are from undiagnosed malaria, which may be misattributed in retrospective enquiries to other febrile causes of death, or vice-versa. Aim To estimate plausible ranges of malaria mortality in India, the most populous country where it remains common. Methods Nationally representative retrospective study of 122,000 deaths during 2001-03 in 6671 areas. Full-time non-medical field workers interviewed families or other respondents about each death, obtaining a half-page narrative plus answers to specific questions about the severity and course of any fevers. Each field report was scanned and emailed to two of 130 trained physicians, who independently coded underlying causes, with discrepancies resolved either via anonymous reconciliation or, failing that, adjudication. Findings Of all coded deaths at ages 1 month to 70 years, 3.6% (2681/75,342) were attributed to malaria. Of these, 2419 (90%) were rural and 2311 (86%) were not in any healthcare facility. Malaria-attributed death rates correlated geographically with local malaria transmission rates derived independently from the Indian malaria control programme, and rose after the wet season began. The adjudicated results suggest 205,000 malaria deaths per year in India before age 70 (55,000 in early childhood, 30,000 at ages 5-14, 120,000 at ages 15-69); cumulative probability 1.8% of death from malaria before age 70. Plausible upper and lower bounds (based only on the initial coding) were 125,000 to 277,000. Interpretation Despite inevitable uncertainty as to which unattended febrile deaths are from malaria, even the lower bound

  10. Two-stage sample-to-answer system based on nucleic acid amplification approach for detection of malaria parasites.

    PubMed

    Liu, Qing; Nam, Jeonghun; Kim, Sangho; Lim, Chwee Teck; Park, Mi Kyoung; Shin, Yong

    2016-08-15

    Rapid, early, and accurate diagnosis of malaria is essential for effective disease management and surveillance, and can reduce morbidity and mortality associated with the disease. Although significant advances have been achieved for the diagnosis of malaria, these technologies are still far from ideal, being time consuming, complex and poorly sensitive as well as requiring separate assays for sample processing and detection. Therefore, the development of a fast and sensitive method that can integrate sample processing with detection of malarial infection is desirable. Here, we report a two-stage sample-to-answer system based on nucleic acid amplification approach for detection of malaria parasites. It combines the Dimethyl adipimidate (DMA)/Thin film Sample processing (DTS) technique as a first stage and the Mach-Zehnder Interferometer-Isothermal solid-phase DNA Amplification (MZI-IDA) sensing technique as a second stage. The system can extract DNA from malarial parasites using DTS technique in a closed system, not only reducing sample loss and contamination, but also facilitating the multiplexed malarial DNA detection using the fast and accurate MZI-IDA technique. Here, we demonstrated that this system can deliver results within 60min (including sample processing, amplification and detection) with high sensitivity (<1 parasite μL(-1)) in a label-free and real-time manner. The developed system would be of great potential for better diagnosis of malaria in low-resource settings.

  11. DNA from pre-erythrocytic stage malaria parasites is detectable by PCR in the faeces and blood of hosts.

    PubMed

    Abkallo, Hussein M; Liu, Weimin; Hokama, Sarina; Ferreira, Pedro E; Nakazawa, Shusuke; Maeno, Yoshimasa; Quang, Nguyen T; Kobayashi, Nobuyuki; Kaneko, Osamu; Huffman, Michael A; Kawai, Satoru; Marchand, Ron P; Carter, Richard; Hahn, Beatrice H; Culleton, Richard

    2014-06-01

    Following the bite of an infective mosquito, malaria parasites first invade the liver where they develop and replicate for a number of days before being released into the bloodstream where they invade red blood cells and cause disease. The biology of the liver stages of malaria parasites is relatively poorly understood due to the inaccessibility of the parasites to sampling during this phase of their life cycle. Here we report the detection in blood and faecal samples of malaria parasite DNA throughout their development in the livers of mice and before the parasites begin their growth in the blood circulation. It is shown that parasite DNA derived from pre-erythrocytic stage parasites reaches the faeces via the bile. We then show that different primate malaria species can be detected by PCR in blood and faecal samples from naturally infected captive macaque monkeys. These results demonstrate that pre-erythrocytic parasites can be detected and quantified in experimentally infected animals. Furthermore, these results have important implications for both molecular epidemiology and phylogenetics of malaria parasites. In the former case, individuals who are malaria parasite negative by microscopy, but PCR positive for parasite DNA in their blood, are considered to be "sub-microscopic" blood stage parasite carriers. We now propose that PCR positivity is not necessarily an indicator of the presence of blood stage parasites, as the DNA could derive from pre-erythrocytic parasites. Similarly, in the case of molecular phylogenetics based on DNA sequences alone, we argue that DNA amplified from blood or faeces does not necessarily come from a parasite species that infects the red blood cells of that particular host.

  12. Detection of edges using local geometry

    NASA Technical Reports Server (NTRS)

    Gualtieri, J. A.; Manohar, M.

    1989-01-01

    Researchers described a new representation, the local geometry, for early visual processing which is motivated by results from biological vision. This representation is richer than is often used in image processing. It extracts more of the local structure available at each pixel in the image by using receptive fields that can be continuously rotated and that go to third order spatial variation. Early visual processing algorithms such as edge detectors and ridge detectors can be written in terms of various local geometries and are computationally tractable. For example, Canny's edge detector has been implemented in terms of a local geometry of order two, and a ridge detector in terms of a local geometry of order three. The edge detector in local geometry was applied to synthetic and real images and it was shown using simple interpolation schemes that sufficient information is available to locate edges with sub-pixel accuracy (to a resolution increase of at least a factor of five). This is reasonable even for noisy images because the local geometry fits a smooth surface - the Taylor series - to the discrete image data. Only local processing was used in the implementation so it can readily be implemented on parallel mesh machines such as the MPP. Researchers expect that other early visual algorithms, such as region growing, inflection point detection, and segmentation can also be implemented in terms of the local geometry and will provide sufficiently rich and robust representations for subsequent visual processing.

  13. Field Evaluation of the ICT Malaria P.f/P.v Immunochromatographic Test for Detection of Plasmodium falciparum and Plasmodium vivax in Patients with a Presumptive Clinical Diagnosis of Malaria in Eastern Indonesia

    PubMed Central

    Tjitra, Emiliana; Suprianto, Sri; Dyer, Mary; Currie, Bart J.; Anstey, Nicholas M.

    1999-01-01

    In areas such as eastern Indonesia where both Plasmodium falciparum and Plasmodium vivax occur, rapid antigen detection tests for malaria need to be able to detect both species. We evaluated the new combined P. falciparum-P. vivax immunochromatographic test (ICT Malaria P.f/P.v.) in Radamata Primary Health Centre, Sumba, Indonesia, from February to May 1998 with 560 symptomatic adults and children with a presumptive clinical diagnosis of malaria. Blinded microscopy was used as the “gold standard,” with all discordant and 20% of concordant results cross-checked blindly. Only 50% of those with a presumptive clinical diagnosis of malaria were parasitemic. The ICT Malaria P.f/P.v immunochromatographic test was sensitive (95.5%) and specific (89.8%) for the diagnosis of falciparum malaria, with a positive predictive value (PPV) and a negative predictive value (NPV) of 88.1 and 96.2%, respectively. HRP2 and panmalarial antigen line intensities were associated with parasitemia density for both species. Although the specificity and NPV for the diagnosis of vivax malaria were 94.8 and 98.2%, respectively, the overall sensitivity (75%) and PPV (50%) for the diagnosis of vivax malaria were less than the desirable levels. The sensitivity for the diagnosis of P. vivax malaria was 96% with parasitemias of >500/μl but only 29% with parasitemias of <500/μl. Nevertheless, compared with the test with HRP2 alone, use of the combined antigen detection test would reduce the rate of undertreatment from 14.7 to 3.6% for microscopy-positive patients, and this would be at the expense of only a modest increase in the rate of overtreatment of microscopy-negative patients from 7.1 to 15.4%. Cost remains a major obstacle to widespread use in areas of endemicity. PMID:10405377

  14. Field evaluation of the ICT malaria P.f/P.v immunochromatographic test for detection of Plasmodium falciparum and Plasmodium vivax in patients with a presumptive clinical diagnosis of malaria in eastern Indonesia.

    PubMed

    Tjitra, E; Suprianto, S; Dyer, M; Currie, B J; Anstey, N M

    1999-08-01

    In areas such as eastern Indonesia where both Plasmodium falciparum and Plasmodium vivax occur, rapid antigen detection tests for malaria need to be able to detect both species. We evaluated the new combined P. falciparum-P. vivax immunochromatographic test (ICT Malaria P.f/P.v.) in Radamata Primary Health Centre, Sumba, Indonesia, from February to May 1998 with 560 symptomatic adults and children with a presumptive clinical diagnosis of malaria. Blinded microscopy was used as the "gold standard," with all discordant and 20% of concordant results cross-checked blindly. Only 50% of those with a presumptive clinical diagnosis of malaria were parasitemic. The ICT Malaria P.f/P.v immunochromatographic test was sensitive (95. 5%) and specific (89.8%) for the diagnosis of falciparum malaria, with a positive predictive value (PPV) and a negative predictive value (NPV) of 88.1 and 96.2%, respectively. HRP2 and panmalarial antigen line intensities were associated with parasitemia density for both species. Although the specificity and NPV for the diagnosis of vivax malaria were 94.8 and 98.2%, respectively, the overall sensitivity (75%) and PPV (50%) for the diagnosis of vivax malaria were less than the desirable levels. The sensitivity for the diagnosis of P. vivax malaria was 96% with parasitemias of >500/microl but only 29% with parasitemias of <500/microl. Nevertheless, compared with the test with HRP2 alone, use of the combined antigen detection test would reduce the rate of undertreatment from 14.7 to 3.6% for microscopy-positive patients, and this would be at the expense of only a modest increase in the rate of overtreatment of microscopy-negative patients from 7.1 to 15. 4%. Cost remains a major obstacle to widespread use in areas of endemicity.

  15. Detecting structure of haplotypes and local ancestry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We present a two-layer hidden Markov model to detect the structure of haplotypes for unrelated individuals. This allows us to model two scales of linkage disequilibrium (one within a group of haplotypes and one between groups), thereby taking advantage of rich haplotype information to infer local an...

  16. Automated detection of malaria in Giemsa-stained thin blood smears.

    PubMed

    Mushabe, Mark C; Dendere, Ronald; Douglas, Tania S

    2013-01-01

    The current gold standard of malaria diagnosis is the manual, microscopy-based analysis of Giemsa-stained blood smears, which is a time-consuming process requiring skilled technicians. This paper presents an algorithm that identifies and counts red blood cells (RBCs) as well as stained parasites in order to perform a parasitaemia calculation. Morphological operations and histogram-based thresholding are used to extract the red blood cells. Boundary curvature calculations and Delaunay triangulation are used to split clumped red blood cells. The stained parasites are classified using a Bayesian classifier with their RGB pixel values as features. The results show 98.5% sensitivity and 97.2% specificity for detecting infected red blood cells.

  17. Automated Detection of Malarial Retinopathy in Digital Fundus Images for Improved Diagnosis in Malawian Children with Clinically Defined Cerebral Malaria.

    PubMed

    Joshi, Vinayak; Agurto, Carla; Barriga, Simon; Nemeth, Sheila; Soliz, Peter; MacCormick, Ian J; Lewallen, Susan; Taylor, Terrie E; Harding, Simon P

    2017-02-15

    Cerebral malaria (CM), a complication of malaria infection, is the cause of the majority of malaria-associated deaths in African children. The standard clinical case definition for CM misclassifies ~25% of patients, but when malarial retinopathy (MR) is added to the clinical case definition, the specificity improves from 61% to 95%. Ocular fundoscopy requires expensive equipment and technical expertise not often available in malaria endemic settings, so we developed an automated software system to analyze retinal color images for MR lesions: retinal whitening, vessel discoloration, and white-centered hemorrhages. The individual lesion detection algorithms were combined using a partial least square classifier to determine the presence or absence of MR. We used a retrospective retinal image dataset of 86 pediatric patients with clinically defined CM (70 with MR and 16 without) to evaluate the algorithm performance. Our goal was to reduce the false positive rate of CM diagnosis, and so the algorithms were tuned at high specificity. This yielded sensitivity/specificity of 95%/100% for the detection of MR overall, and 65%/94% for retinal whitening, 62%/100% for vessel discoloration, and 73%/96% for hemorrhages. This automated system for detecting MR using retinal color images has the potential to improve the accuracy of CM diagnosis.

  18. Automated Detection of Malarial Retinopathy in Digital Fundus Images for Improved Diagnosis in Malawian Children with Clinically Defined Cerebral Malaria

    NASA Astrophysics Data System (ADS)

    Joshi, Vinayak; Agurto, Carla; Barriga, Simon; Nemeth, Sheila; Soliz, Peter; MacCormick, Ian J.; Lewallen, Susan; Taylor, Terrie E.; Harding, Simon P.

    2017-02-01

    Cerebral malaria (CM), a complication of malaria infection, is the cause of the majority of malaria-associated deaths in African children. The standard clinical case definition for CM misclassifies ~25% of patients, but when malarial retinopathy (MR) is added to the clinical case definition, the specificity improves from 61% to 95%. Ocular fundoscopy requires expensive equipment and technical expertise not often available in malaria endemic settings, so we developed an automated software system to analyze retinal color images for MR lesions: retinal whitening, vessel discoloration, and white-centered hemorrhages. The individual lesion detection algorithms were combined using a partial least square classifier to determine the presence or absence of MR. We used a retrospective retinal image dataset of 86 pediatric patients with clinically defined CM (70 with MR and 16 without) to evaluate the algorithm performance. Our goal was to reduce the false positive rate of CM diagnosis, and so the algorithms were tuned at high specificity. This yielded sensitivity/specificity of 95%/100% for the detection of MR overall, and 65%/94% for retinal whitening, 62%/100% for vessel discoloration, and 73%/96% for hemorrhages. This automated system for detecting MR using retinal color images has the potential to improve the accuracy of CM diagnosis.

  19. Automated Detection of Malarial Retinopathy in Digital Fundus Images for Improved Diagnosis in Malawian Children with Clinically Defined Cerebral Malaria

    PubMed Central

    Joshi, Vinayak; Agurto, Carla; Barriga, Simon; Nemeth, Sheila; Soliz, Peter; MacCormick, Ian J.; Lewallen, Susan; Taylor, Terrie E.; Harding, Simon P.

    2017-01-01

    Cerebral malaria (CM), a complication of malaria infection, is the cause of the majority of malaria-associated deaths in African children. The standard clinical case definition for CM misclassifies ~25% of patients, but when malarial retinopathy (MR) is added to the clinical case definition, the specificity improves from 61% to 95%. Ocular fundoscopy requires expensive equipment and technical expertise not often available in malaria endemic settings, so we developed an automated software system to analyze retinal color images for MR lesions: retinal whitening, vessel discoloration, and white-centered hemorrhages. The individual lesion detection algorithms were combined using a partial least square classifier to determine the presence or absence of MR. We used a retrospective retinal image dataset of 86 pediatric patients with clinically defined CM (70 with MR and 16 without) to evaluate the algorithm performance. Our goal was to reduce the false positive rate of CM diagnosis, and so the algorithms were tuned at high specificity. This yielded sensitivity/specificity of 95%/100% for the detection of MR overall, and 65%/94% for retinal whitening, 62%/100% for vessel discoloration, and 73%/96% for hemorrhages. This automated system for detecting MR using retinal color images has the potential to improve the accuracy of CM diagnosis. PMID:28198460

  20. Action plan to regain unnecessary deferred blood donors due to malaria risk in Turkey.

    PubMed

    Değirmenci, Aysu; Döşkaya, Mert; Caner, Ayşe; Nergis, Sebnem; Gül, Kadri; Aydınok, Yeşim; Ertop, Tufan; Aksoy, Nurten; Korkmaz, Metin; Alkan, Mehmet Ziya; Üner, Ahmet; Gürüz, Yüksel

    2012-06-01

    Malaria was expected to be a major problem during blood donation in Turkey due to existence of malaria cases in southeastern region of Turkey. The present study aimed for the first time, to investigate malaria in "donors deferred for malaria risk" and to determine the regional rates of malaria deferral in Turkey. Blood samples were collected from several Blood Banks of southeastern provinces where local malaria cases still exist and from Blood Bank of Ege University Medical School (EUMS) located in western Turkey where malaria is eradicated decades ago. Plasmodium spp. and specific antibodies were investigated by stained smears, antigen detection, PCR and ELISA. Among the donors deferred for malaria risk, Plasmodium spp. were not detected by microscopy, PCR or antigen detection. Seroprevalances were 2% and 3.92% in western and southeastern regions, respectively. Rate of donor deferral for malaria risk was 0.9% in EUMS and deferrals were exclusively because of travel to southeastern Turkey. In southeastern provinces, deferrals were mainly due to malaria like fever history. The present study first time assessed regional rates of donor deferral due to malaria risk in Turkey. Previously, malaria was expected to be a major problem during blood donation in Turkey due to existence of malaria cases in southeastern region of Turkey. The results of the study showed that 97% of the deferrals were unnecessary. In conclusion, to reduce unnecessary donor deferrals in Turkey, in addition to comprehensive questioning for malaria history, the usage of a malaria antibody screening method should be initiated prior to deferral decision.

  1. Detection of avian malaria (Plasmodium spp.) in native land birds of American Samoa

    USGS Publications Warehouse

    Jarvi, S.I.; Farias, M.E.M.; Baker, H.; Freifeld, H.B.; Baker, P.E.; Van Gelder, E.; Massey, J.G.; Atkinson, C.T.

    2003-01-01

    This study documents the presence of Plasmodium spp. in landbirds of central Polynesia. Blood samples collected from eight native and introduced species from the island of Tutuila, American Samoa were evaluated for the presence of Plasmodium spp. by nested rDNA PCR, serology and/or microscopy. A total of 111/188 birds (59%) screened by nested PCR were positive. Detection of Plasmodium spp. was verified by nucleotide sequence comparisons of partial 18S ribosomal RNA and TRAP (thrombospondin-related anonymous protein) genes using phylogenetic analyses. All samples screened by immunoblot to detect antibodies that cross-react with Hawaiian isolates of Plasmodium relictum (153) were negative. Lack of cross-reactivity is probably due to antigenic differences between the Hawaiian and Samoan Plasmodium isolates. Similarly, all samples examined by microscopy (214) were negative. The fact that malaria is present, but not detectable by blood smear evaluation is consistent with low peripheral parasitemia characteristic of chronic infections. High prevalence of apparently chronic infections, the relative stability of the native land bird communities, and the presence of mosquito vectors which are considered endemic and capable of transmitting avian Plasmodia, suggest that these parasites are indigenous to Samoa and have a long coevolutionary history with their hosts.

  2. Molecular Detection of Malaria at Delivery Reveals a High Frequency of Submicroscopic Infections and Associated Placental Damage in Pregnant Women from Northwest Colombia

    PubMed Central

    Arango, Eliana M.; Samuel, Roshini; Agudelo, Olga M.; Carmona-Fonseca, Jaime; Maestre, Amanda; Yanow, Stephanie K.

    2013-01-01

    Plasmodium infection in pregnancy causes substantial maternal and infant morbidity and mortality. In Colombia, both P. falciparum and P. vivax are endemic, but the impact of either species on pregnancy is largely unknown in this country. A cross-sectional study was carried out with 96 pregnant women who delivered at their local hospital. Maternal, placental, and cord blood were tested for malaria infection by microscopy and real-time quantitative polymerase chain reaction (qPCR). A high frequency of infection was detected by qPCR (45%). These infections had low concentrations of parasite DNA, and 79% were submicroscopic. Submicroscopic infections were associated with placental villitis and intervillitis. In conclusion, the overall frequency of Plasmodium infection at delivery in Colombia is much higher than previously reported. These data prompt a re-examination of the local epidemiology of malaria using molecular diagnostics to establish the clinical relevance of submicroscopic infections during pregnancy as well as their consequences for mothers and newborns. PMID:23716408

  3. Artemisinin resistance containment project in Thailand. (I): Implementation of electronic-based malaria information system for early case detection and individual case management in provinces along the Thai-Cambodian border

    PubMed Central

    2012-01-01

    Background The Bureau of Vector-borne Diseases, Ministry of Public Health, Thailand, has implemented an electronic Malaria Information System (eMIS) as part of a strategy to contain artemisinin resistance. The attempt corresponds to the WHO initiative, funded by the Bill & Melinda Gates Foundation, to contain anti-malarial drug resistance in Southeast Asia. The main objective of this study was to demonstrate the eMIS’ functionality and outputs after implementation for use in the Thailand artemisinin-resistance containment project. Methods The eMIS had been functioning since 2009 in seven Thai-Cambodian border provinces. The eMIS has covered 61 malaria posts/clinics, 27 Vector-borne Disease Units covering 12,508 hamlets at risk of malaria infections. The eMIS was designed as an evidence-based and near real-time system to capture data for early case detection, intensive case investigation, monitoring drug compliance and on/off-site tracking of malarial patients, as well as collecting data indicating potential drug resistance among patients. Data captured by the eMIS in 2008–2011 were extracted and presented. Results The core functionalities of the eMIS have been utilized by malaria staff at all levels, from local operational units to ministerial management. The eMIS case detection module suggested decreasing trends during 2009–2011; the number of malaria cases detected in the project areas over the years studied were 3818, 2695, and 2566, with sero-positive rates of 1.24, 0.98, and 1.16%, respectively. The eMIS case investigation module revealed different trends in weekly Plasmodium falciparum case numbers, when classified by responsible operational unit, local and migrant status, and case-detection type. It was shown that most Thai patients were infected within their own residential district, while migrants were infected either at their working village or from across the border. The data mapped in the system suggested that P. falciparum-infected cases and

  4. Efficacy of local neem extracts for sustainable malaria vector control in an African village

    PubMed Central

    Gianotti, Rebecca L; Bomblies, Arne; Dafalla, Mustafa; Issa-Arzika, Ibrahim; Duchemin, Jean-Bernard; Eltahir, Elfatih AB

    2008-01-01

    Background Larval control of malaria vectors has been historically successful in reducing malaria transmission, but largely fell out of favour with the introduction of synthetic insecticides and bed nets. However, an integrated approach to malaria control, including larval control methods, continues to be the best chance for success, in view of insecticide resistance, the behavioural adaptation of the vectors to changing environments and the difficulties of reaching the poorest populations most at risk,. Laboratory studies investigating the effects of neem seed (Azadirachta indica) extracts on Anopheles larvae have shown high rates of larval mortality and reductions in adult longevity, as well as low potential for resistance development. Methods This paper describes a method whereby seeds of the neem tree can be used to reduce adult Anopheles gambiae s.l. abundance in a way that is low cost and can be implemented by residents of rural villages in western Niger. The study was conducted in Banizoumbou village, western Niger. Neem seeds were collected from around the village. Dried seeds were ground into a coarse powder, which was then sprinkled onto known Anopheles larvae breeding habitats twice weekly during the rainy season 2007. Adult mosquitoes were captured on a weekly basis in the village and captures compared to those from 2005 and 2006 over the same period. Adult mosquitoes were also captured in a nearby village, Zindarou, as a control data set and compared to those from Banizoumbou. Results It was found that twice-weekly applications of the powder to known breeding habitats of Anopheles larvae in 2007 resulted in 49% fewer adult female Anopheles gambiae s.l. mosquitoes in Banizoumbou, compared with previous captures under similar environmental conditions and with similar habitat characteristics in 2005 and 2006. The productivity of the system in 2007 was found to be suppressed compared to the mean behaviour of 2005 and 2006 in Banizoumbou, whereas no change

  5. History of malaria control in Tajikistan and rapid malaria appraisal in an agro-ecological setting

    PubMed Central

    Matthys, Barbara; Sherkanov, Tohir; Karimov, Saifudin S; Khabirov, Zamonidin; Mostowlansky, Till; Utzinger, Jürg; Wyss, Kaspar

    2008-01-01

    Background Reported malaria cases in rice growing areas in western Tajikistan were at the root of a rapid appraisal of the local malaria situation in a selected agro-ecological setting where only scarce information was available. The rapid appraisal was complemented by a review of the epidemiology and control of malaria in Tajikistan and Central Asia from 1920 until today. Following a resurgence in the 1990s, malaria transmission has been reduced considerably in Tajikistan as a result of concerted efforts by the government and international agencies. The goal for 2015 is transmission interruption, with control interventions and surveillance currently concentrated in the South, where foci of Plasmodium vivax and Plasmodium falciparum persist. Methods The rapid malaria appraisal was carried out in six communities of irrigated rice cultivation during the peak of malaria transmission (August/September 2007) in western Tajikistan. In a cross-sectional survey, blood samples were taken from 363 schoolchildren and examined for Plasmodium under a light microscope. A total of 56 farmers were interviewed about agricultural activities and malaria. Potential Anopheles breeding sites were characterized using standardized procedures. A literature review on the epidemiology and control of malaria in Tajikistan was conducted. Results One case of P. vivax was detected among the 363 schoolchildren examined (0.28%). The interviewees reported to protect themselves against mosquito bites and used their own concepts on fever conditions, which do not distinguish between malaria and other diseases. Three potential malaria vectors were identified, i.e. Anopheles superpictus, Anopheles pulcherrimus and Anopheles hyrcanus in 58 of the 73 breeding sites examined (79.5%). Rice paddies, natural creeks and man-made ponds were the most important Anopheles habitats. Conclusion The presence of malaria vectors and parasite reservoirs, low awareness of, and protection against malaria in the face of

  6. High resolution FTIR imaging provides automated discrimination and detection of single malaria parasite infected erythrocytes on glass.

    PubMed

    Perez-Guaita, David; Andrew, Dean; Heraud, Philip; Beeson, James; Anderson, David; Richards, Jack; Wood, Bayden R

    2016-06-23

    New highly sensitive tools for malaria diagnostics are urgently needed to enable the detection of infection in asymptomatic carriers and patients with low parasitemia. In pursuit of a highly sensitive diagnostic tool that can identify parasite infections at the single cell level, we have been exploring Fourier transform infrared (FTIR) microscopy using a Focal Plane Array (FPA) imaging detector. Here we report for the first time the application of a new optic configuration developed by Agilent that incorporates 25× condenser and objective Cassegrain optics with a high numerical aperture (NA = 0.81) along with additional high magnification optics within the microscope to provide 0.66 micron pixel resolution (total IR system magnification of 61×) to diagnose malaria parasites at the single cell level on a conventional glass microscope slide. The high quality images clearly resolve the parasite's digestive vacuole demonstrating sub-cellular resolution using this approach. Moreover, we have developed an algorithm that first detects the cells in the infrared image, and secondly extracts the average spectrum. The average spectrum is then run through a model based on Partial Least Squares-Discriminant Analysis (PLS-DA), which diagnoses unequivocally the infected from normal cells. The high quality images, and the fact this measurement can be achieved without a synchrotron source on a conventional glass slide, shows promise as a potential gold standard for malaria detection at the single cell level.

  7. Direct optical nanoscopy with axially localized detection

    NASA Astrophysics Data System (ADS)

    Bourg, N.; Mayet, C.; Dupuis, G.; Barroca, T.; Bon, P.; Lécart, S.; Fort, E.; Lévêque-Fort, S.

    2015-09-01

    Evanescent light excitation is widely used in super-resolution fluorescence microscopy to confine light and reduce background noise. Here, we propose a method of exploiting evanescent light in the context of emission. When a fluorophore is located in close proximity to a medium with a higher refractive index, its near-field component is converted into light that propagates beyond the critical angle. This so-called supercritical-angle fluorescence can be captured using a high-numerical-aperture objective and used to determine the axial position of the fluorophore with nanometre precision. We introduce a new technique for three-dimensional nanoscopy that combines direct stochastic optical reconstruction microscopy (dSTORM) with dedicated detection of supercritical-angle fluorescence emission. We demonstrate that our approach of direct optical nanoscopy with axially localized detection (DONALD) typically yields an isotropic three-dimensional localization precision of 20 nm within an axial range of ∼150 nm above the coverslip.

  8. Probe functionalization with a Rhop-3 antibody: toward a Rhop-3 antigen immunosensor for detection of malaria.

    PubMed

    Saleh, Salaam; Moreno-Molek, Susan; Perera, Indika; Riga, Alan; Sam-Yellowe, Tobili; Bayachou, Mekki

    2012-03-01

    The antibody specific for the malaria protein, Rhop-3, and FL-Rhop-3, were immobilized on the surface of a gold electrode modified with cysteamine. Colloidal gold was used to enhance the detection signal for Rhop-3 antigens. The Rhop-3 antibody was also immobilized on gold electrodes preactivated with dithiobis(succinimidyl proprionate) (DSP). Immobilization was performed at room temperature and at 37 °C. Cyclic voltammetry (CV) was used to monitor the interaction between the immobilized antibody and its cognate antigen in solution, using ferricyanide, K3Fe(CN)6, as reporting electroactive probe. Tests indicate recognition of Rhop-3 protein by the immobilized antibody. Antigen recognition was enhanced by incubation at 37 °C compared with room-temperature incubation. Our results suggest that an immunosensor can be developed and optimized to aid detection of Rhop-3 antigens in samples from malaria patients. As far as we are aware, this is the first amperometric immunosensor targeting Rhop-3 antigen as a malaria biomarker.

  9. Automated detection of malaria-associated pseudoeosinophilia and abnormal WBC scattergram by the Sysmex XE-2100 hematology analyzer: a clinical study with 1,801 patients and real-time quantitative PCR analysis in vivax malaria-endemic area.

    PubMed

    Yoo, Jong-Ha; Song, Jaewoo; Lee, Kyung-A; Sun, Young-Kyu; Kim, Young-Ah; Park, Tae Sung; Choi, Jong Rak

    2010-03-01

    Recently, the XE-2100 hematology analyzer was investigated in a rather small patient group; pseudoeosinophilia or abnormal white blood cell (WBC) scattergrams reported by this instrument were considered as significantly valuable diagnostic parameters in detecting vivax malaria. This study was conducted not only to assess the usefulness of pseudoeosinophilia or abnormal WBC scattergram in vivax malaria-endemic areas with large patient groups (N = 1,801) but also to investigate the correlation of parasitemia and platelet count with pseudoeosinophilia and abnormal WBC scattergrams. Of the 1,801 analyzed patients, 413 (22.9%) were found to have malaria by Wright-Giemsa stained blood smears. Overall, either pseudoeosinophilia or abnormal WBC scattergram was detected in 191 of 413 malaria patients and 4 of 1,388 patients without malaria (sensitivity = 46.2%, specificity = 99.7%). We suggest that clinical hematology laboratories using the XE-2100 analyzer should be aware of such specific parameters, even with the absence of a clinical request.

  10. The identification of malaria in paleopathology-An in-depth assessment of the strategies to detect malaria in ancient remains.

    PubMed

    Bianucci, Raffaella; Araujo, Adauto; Pusch, Carsten M; Nerlich, Andreas G

    2015-12-01

    The comprehensive analyses of human remains from various places and time periods, either by immunological or molecular approaches, provide circumstantial evidence that malaria tropica haunted humankind at least since dynastic ancient Egypt. Here we summarize the "actual state-of-the-art" of these bio-molecular investigations and offer a solid basis for the discussion of the paleopathology of malaria in human history.

  11. Malaria Facts

    MedlinePlus

    ... Laveran and the Discovery of the Malaria Parasite Ross and the Discovery that Mosquitoes Transmit Malaria Parasites ... for work associated with malaria: to Sir Ronald Ross (1902), Charles Louis Alphonse Laveran (1907), Julius Wagner- ...

  12. Environmental data analysis and remote sensing for early detection of dengue and malaria

    NASA Astrophysics Data System (ADS)

    Rahman, Md Z.; Roytman, Leonid; Kadik, Abdelhamid; Rosy, Dilara A.

    2014-06-01

    Malaria and dengue fever are the two most common mosquito-transmitted diseases, leading to millions of serious illnesses and deaths each year. Because the mosquito vectors are sensitive to environmental conditions such as temperature, precipitation, and humidity, it is possible to map areas currently or imminently at high risk for disease outbreaks using satellite remote sensing. In this paper we propose the development of an operational geospatial system for malaria and dengue fever early warning; this can be done by bringing together geographic information system (GIS) tools, artificial neural networks (ANN) for efficient pattern recognition, the best available ground-based epidemiological and vector ecology data, and current satellite remote sensing capabilities. We use Vegetation Health Indices (VHI) derived from visible and infrared radiances measured by satellite-mounted Advanced Very High Resolution Radiometers (AVHRR) and available weekly at 4-km resolution as one predictor of malaria and dengue fever risk in Bangladesh. As a study area, we focus on Bangladesh where malaria and dengue fever are serious public health threats. The technology developed will, however, be largely portable to other countries in the world and applicable to other disease threats. A malaria and dengue fever early warning system will be a boon to international public health, enabling resources to be focused where they will do the most good for stopping pandemics, and will be an invaluable decision support tool for national security assessment and potential troop deployment in regions susceptible to disease outbreaks.

  13. Malaria ecotypes and stratification.

    PubMed

    Schapira, Allan; Boutsika, Konstantina

    2012-01-01

    To deal with the variability of malaria, control programmes need to stratify their malaria problem into a number of smaller units. Such stratification may be based on the epidemiology of malaria or on its determinants such as ecology. An ecotype classification was developed by the World Health Organization (WHO) around 1990, and it is time to assess its usefulness for current malaria control as well as for malaria modelling on the basis of published research. Journal and grey literature was searched for articles on malaria or Anopheles combined with ecology or stratification. It was found that all malaria in the world today could be assigned to one or more of the following ecotypes: savanna, plains and valleys; forest and forest fringe; foothill; mountain fringe and northern and southern fringes; desert fringe; coastal and urban. However, some areas are in transitional or mixed zones; furthermore, the implications of any ecotype depend on the biogeographical region, sometimes subregion, and finally, the knowledge on physiography needs to be supplemented by local information on natural, anthropic and health system processes including malaria control. Ecotyping can therefore not be seen as a shortcut to determine control interventions, but rather as a framework to supplement available epidemiological and entomological data so as to assess malaria situations at the local level, think through the particular risks and opportunities and reinforce intersectoral action. With these caveats, it does however emerge that several ecotypic distinctions are well defined and have relatively constant implications for control within certain biogeographic regions. Forest environments in the Indo-malay and the Neotropics are, with a few exceptions, associated with much higher malaria risk than in adjacent areas; the vectors are difficult to control, and the anthropic factors also often converge to impose constraints. Urban malaria in Africa is associated with lower risk than savanna

  14. A rapid malaria appraisal in the Venezuelan Amazon

    PubMed Central

    2009-01-01

    Background While the federal state of Amazonas bears the highest risk for malaria in Venezuela (2007: 68.4 cases/1000 inhabitants), little comprehensive information about the malaria situation is available from this area. The purpose of this rapid malaria appraisal (RMA) was to provide baseline data about malaria and malaria control in Amazonas. Methods The RMA methodology corresponds to a rapid health impact assessment (HIA) as described in the 1999 Gothenburg consensus. In conjunction with the actors of the malaria surveillance system, all useful data and information, which were accessible within a limited time-frame of five visits to Amazonas, were collected, analysed and interpreted. Results Mortality from malaria is low (< 1 in 105) and slide positivity rates have stayed at the same level for the last two decades (15% ± 6% (SD)). Active case detection accounts for ca. 40% of slides taken. The coverage of the censured population with malaria notification points (NPs) has been achieved in recent years. The main parasite is Plasmodium vivax (84% of cases). The proportion of Plasmodium falciparum is on the decline, possibly driven by the introduction of cost-free artemisinin-based combination therapy (ACT) (1988: 33.4%; 2007: 15.4%). Monitoring and documentation is complete, systematic and consistent, but poorly digitalized. Malaria transmission displayed a visible lag behind rainfall in the capital municipality of Atures, but not in the other municipalities. In comparison to reference microscopy, quality of field microscopy and rapid diagnostic tests (RDTs) is suboptimal (kappa < 0.75). Hot spots of malaria risk were seen in some indigenous ethnic groups. Conflicting strategies in respect of training of community health workers (CHW) and the introduction of new diagnostic tools (RDTs) were observed. Conclusion Malaria control is possible, even in tropical rain forest areas, if the health system is working adequately. Interventions have to be carefully designed

  15. Evaluation of Antigen Detection Tests, Microscopy, and Polymerase Chain Reaction for Diagnosis of Malaria in Peripheral Blood in Asymptomatic Pregnant Women in Nanoro, Burkina Faso

    PubMed Central

    Kattenberg, Johanna H.; Tahita, Christian M.; Versteeg, Inge A. J.; Tinto, Halidou; Traoré/Coulibaly, Maminata; D'Alessandro, Umberto; Schallig, Henk D. F. H.; Mens, Petra F.

    2012-01-01

    Rapid diagnostics tests (RDTs) detect malaria specific antigen(s) in the circulation, even when parasites are sequestered in the placenta and not visible by microscopy. However, research on their diagnostic accuracy during pregnancy is limited. Pregnant women (n = 418) were screened for malaria during routine antenatal care by using two RDTs that detect histidine-rich protein 2 (HRP2) or Plasmodium lactate dehydrogenase, and enzyme-linked immunosorbent assays with antibodies that detect dihydrofolate reductase–thymidylate synthase or heme-detoxification protein, and compared with real-time polymerase chain reaction (RT-PCR) and microscopy for evaluation of their diagnostic accuracy. Prevalence of malaria infection was high (53% by PCR). The RT-PCR and the HRP2 RDT detected most cases of malaria during pregnancy, whereas microscopy, the Plasmodium lactate dehydrogenase RDT, and enzyme-linked immunosorbent assays for dihydrofolate reductase–thymidylate synthase and heme-detoxification protein antibodies did not detect several low-density infections. Therefore, the HRP2 RDT could be a useful tool in high-transmission areas for diagnosis of malaria in asymptomatic pregnant women. PMID:22859362

  16. Towards a noninvasive approach to malaria diagnosis: detection of parasite DNA in body secretions and surface mucosa.

    PubMed

    A-Elgayoum, Salwa M E; El-Rayah, El-Amin; Giha, Hayder A

    2010-01-01

    Invasive procedures for diagnostic or therapeutic purposes bear a relative risk of transmission of serious blood-borne infectious disease. In this study, a noninvasive approach to malaria diagnosis using polymerase chain reaction (PCR) for the detection of parasite DNA in saliva, buccal mucosa and urine (alternative samples) was examined. Saliva, buccal mucosa and urine samples were collected simultaneously with blood samples from 93 patients with microscopically confirmed Plasmodium falciparum infection. Species-specific primers detected the parasite DNA only in blood samples. However, when the PCR analysis was repeated using MSP1 and MSP2 primers in a subgroup of 21 complete sets of samples, the parasite DNA was detected in all except 3 samples, which were found to be negative with the MSP2 primers. Parasite density, body temperature or patient age did not influence the PCR results. In conclusion, P. falciparum parasite DNA was detected equally in saliva, buccal mucosa and urine of malaria patients, regardless of their ages, body temperatures or parasite density. Surprisingly, the parasite DNA was not amplified by species-specific primers in the alternative samples whereas it was in the blood samples.

  17. SEASONAL DISTRIBUTION OF MALARIA VECTORS (DIPTERA: CULICIDAE) IN RURAL LOCALITIES OF PORTO VELHO, RONDÔNIA, BRAZILIAN AMAZON

    PubMed Central

    GIL, Luiz Herman Soares; RODRIGUES, Moreno de Souza; de LIMA, Alzemar Alves; KATSURAGAWA, Tony Hiroshi

    2015-01-01

    We conducted a survey of the malaria vectors in an area where a power line had been constructed, between the municipalities of Porto Velho and Rio Branco, in the states of Rondônia and Acre, respectively. The present paper relates to the results of the survey of Anopheles fauna conducted in the state of Rondônia. Mosquito field collections were performed in six villages along the federal highway BR 364 in the municipality of Porto Velho, namely Porto Velho, Jaci Paraná, Mutum Paraná, Vila Abunã, Vista Alegre do Abunã, and Extrema. Mosquito captures were performed at three distinct sites in each locality during the months of February, July, and October 2011 using a protected human-landing catch method; outdoor and indoor captures were conducted simultaneously at each site for six hours. In the six sampled areas, we captured 2,185 mosquitoes belonging to seven Anopheles species. Of these specimens, 95.1% consisted of Anopheles darlingi, 1.8% An. triannulatus l.s., 1.7% An. deaneorum, 0.8% An. konderi l.s., 0.4 An. braziliensis, 0.1% An. albitarsis l.s., and 0.1% An. benarrochi. An. darlingi was the only species found in all localities; the remaining species occurred in sites with specific characteristics. PMID:26200969

  18. Preparation for malaria resurgence in China: approach in risk assessment and rapid response.

    PubMed

    Qian, Ying-Jun; Zhang, Li; Xia, Zhi-Gui; Vong, Sirenda; Yang, Wei-Zhong; Wang, Duo-Quan; Xiao, Ning

    2014-01-01

    With the shrinking of indigenous malaria cases and endemic areas in the People's Republic of China (P.R. China), imported malaria predominates over all reported cases accounting for more than 90% of the total. On the way to eliminate malaria, prompt detection and rapid response to the imported cases are crucial for the prevention of secondary transmission in previous endemic areas. Through a comprehensive literature review, this chapter aims to identify risk determinants of potential local transmission caused by the imported malaria cases and discusses gaps to be addressed to reach the elimination goal by 2020. Current main gaps with respect to dealing with potential malaria resurgence in P.R. China include lack of cross-sectoral cooperation, lack of rapid response and risk assessment, poor public awareness, and inadequate research and development in the national malaria elimination programme.

  19. Processing and Microfiltration of Mosquitoes for Malaria Antigen Detection in a Rapid Dot Immunobinding Assay

    DTIC Science & Technology

    1990-08-01

    then mixed and homogenized to- as Leishmania spp. in sand flies and Borrelia spp. in ticks. gether as described above with 0.01% SDS. A total of 100 1...through the mem- tweede patient met malaria tropica op natuurlijke wijzeverkregen in Nederland. Ned. Tijdschr. Geneeskd. 125:375-377.branes. As positive

  20. Five-minute Giemsa stain for rapid detection of malaria parasites in blood smears.

    PubMed

    Jager, M M; Murk, J L; Piqué, R D; Hekker, T A M; Vandenbroucke-Grauls, C M J E

    2011-01-01

    The Giemsa stain is used as the gold standard for the diagnosis of malaria on blood smears. The classical staining procedure requires between 30 and 45 min. We modified the Giemsa stain and reduced the staining time to 5 min without any loss of quality.

  1. Detection of 1014F kdr mutation in four major Anopheline malaria vectors in Indonesia

    PubMed Central

    2010-01-01

    Background Malaria is a serious public health problem in Indonesia, particularly in areas outside Java and Bali. The spread of resistance to the currently available anti-malarial drugs or insecticides used for mosquito control would cause an increase in malaria transmission. To better understand patterns of transmission and resistance in Indonesia, an integrated mosquito survey was conducted in three areas with different malaria endemicities, Purworejo in Central Java, South Lampung District in Sumatera and South Halmahera District in North Mollucca. Methods Mosquitoes were collected from the three areas through indoor and outdoor human landing catches (HLC) and indoor restinging catches. Specimens were identified morphologically by species and kept individually in 1.5 ml Eppendorf microtube. A fragment of the VGSC gene from 95 mosquito samples was sequenced and kdr allelic variation determined. Results The molecular analysis of these anopheline mosquitoes revealed the existence of the 1014F allele in 4 major malaria vectors from South Lampung. These species include, Anopheles sundaicus, Anopheles aconitus, Anopheles subpictus and Anopheles vagus. The 1014F allele was not found in the other areas. Conclusion The finding documents the presence of this mutant allele in Indonesia, and implies that selection pressure on the Anopheles population in this area has occurred. Further studies to determine the impact of the resistance allele on the efficacy of pyrethroids in control programmes are needed. PMID:21054903

  2. Differential immune response associated to malaria outcome is detectable in peripheral blood following Plasmodium yoelii infection in mice.

    PubMed

    Azcárate, Isabel G; Marín-García, Patricia; Kamali, Alí N; Pérez-Benavente, Susana; Puyet, Antonio; Diez, Amalia; Bautista, José M

    2014-01-01

    Malaria infection in humans elicits a wide range of immune responses that can be detected in peripheral blood, but we lack detailed long-term follow-up data on the primary and subsequent infections that lead to naturally acquired immunity. Studies on antimalarial immune responses in mice have been based on models yielding homogenous infection profiles. Here, we present a mouse model in which a heterogeneous course of Plasmodium yoelii lethal malaria infection is produced in a non-congenic ICR strain to allow comparison among different immunological and clinical outcomes. Three different disease courses were observed ranging from a fatal outcome, either early or late, to a self-resolved infection that conferred long-term immunity against re-infection. Qualitative and quantitative changes produced in leukocyte subpopulations and cytokine profiles detected in peripheral blood during the first week of infection revealed that monocytes, dendritic cells and immature B cells were the main cell subsets present in highly-parasitized mice dying in the first week after infection. Besides, CD4(+)CD25(high) T cells expanded at an earlier time point in early deceased mice than in surviving mice and expressed higher levels of intracellular Foxp3 protein. In contrast, survivors showed a limited increase of cytokines release and stable circulating innate cells. From the second week of infection, mice that would die or survive showed similar immune profiles, although CD4(+)CD25(high) T cells number increased earlier in mice with the worst prognosis. In surviving mice the expansion of activated circulating T cell and switched-class B cells with a long-term protective humoral response from the second infection week is remarkable. Our results demonstrate that the follow-up studies of immunological blood parameters during a malaria infection can offer information about the course of the pathological process and the immune response.

  3. Preliminary Biological Studies on Larvae and Adult Anopheles Mosquitoes (Diptera: Culicidae) in Miraflores, a Malaria Endemic Locality in Guaviare Department, Amazonian Colombia

    PubMed Central

    JIMÉNEZ, IRENE P.; CONN, JAN E.; BROCHERO, HELENA

    2015-01-01

    In the malaria endemic municipality of Miraflores in southeastern Amazonian Colombia, several aspects of the biology of local Anopheles species were investigated to supplement the limited entomological surveillance information available and to provide baseline data for malaria prevention and vector control. Anopheles darlingi Root, 1926 was the most abundant species (95.6%), followed by Anopheles braziliensis (Chagas) (3.6%) and Anopheles oswaldoi s.l. (Peryassu) (0.7%). During the dry season, exophagic activity was prevalent only between 1800–2100 hours; after this (2100–0600 hours) only endophagy was encountered. In contrast, during the rainy season, both endophagy and exophagy occurred throughout the collection period. The human biting rate for An. darlingi was 8.6. This species was positive for Plasmodium vivax VK210 with a sporozoite rate = 0.13 (1/788). Breeding sites corresponded to stream (n = 7), flooded excavations (n = 4), flooded forest (n = 1), wetlands (n = 2), and an abandoned water reservoir (n = 1). An. darlingi predominated in these sites in both seasons. Based on these data, An. darlingi is the main local malaria vector, and we recommend that local prevention and control efforts focus on strengthening entomological surveillance to determine potential changes of species biting behavior and time to reduce human–vector interactions. PMID:25276930

  4. Evidence that the Malaria Parasite Plasmodium falciparum Putative Rhoptry Protein 2 Localizes to the Golgi Apparatus throughout the Erythrocytic Cycle

    PubMed Central

    Hallée, Stéphanie; Richard, Dave

    2015-01-01

    Invasion of a red blood cell by Plasmodium falciparum merozoites is an essential step in the malaria lifecycle. Several of the proteins involved in this process are stored in the apical complex of the merozoite, a structure containing secretory organelles that are released at specific times during invasion. The molecular players involved in erythrocyte invasion thus represent potential key targets for both therapeutic and vaccine-based strategies to block parasite development. In our quest to identify and characterize new effectors of invasion, we investigated the P. falciparum homologue of a P. berghei protein putatively localized to the rhoptries, the Putative rhoptry protein 2 (PbPRP2). We show that in P. falciparum, the protein colocalizes extensively with the Golgi apparatus across the asexual erythrocytic cycle. Furthermore, imaging of merozoites caught at different times during invasion show that PfPRP2 is not secreted during the process instead staying associated with the Golgi apparatus. Our evidence therefore suggests that PfPRP2 is a Golgi protein and that it is likely not a direct effector in the process of merozoite invasion. PMID:26375591

  5. Plasmodium falciparum: food vacuole localization of nitric oxide-derived species in intraerythrocytic stages of the malaria parasite

    PubMed Central

    Ostera, Graciela; Tokumasu, Fuyuki; Oliveira, Fabiano; Sa, Juliana; Furuya, Tetsuya; Teixeira, Clarissa; Dvorak, James

    2008-01-01

    Nitric oxide (NO) has diverse biological functions. Numerous studies have documented NO’s biosynthetic pathway in a wide variety of organisms. Little is known, however, about NO production in intraerythrocytic Plasmodium falciparum. Using diaminorhodamine-4-methyl acetoxymethylester (DAR-4M AM), a fluorescent indicator, we obtained direct evidence of NO and NO-derived reactive nitrogen species (RNS) production in intraerythrocytic P. falciparum parasites, as well as in isolated food vacuoles from trophozoite stage parasites. We preliminarily identified two gene sequences that might be implicated in NO synthesis in intraerythrocytic P. falciparum. We showed localization of the protein product of one of these two genes, a molecule that is structurally similar to a plant nitrate reductase, in trophozoite food vacuole membranes. We confirmed previous reports on the antiproliferative effect of NOS (nitric oxide synthase) inhibitors in P.falciparum cultures; however, we did not obtain evidence that NOS inhibitors had the ability to inhibit RNS production or that there is an active NOS in mature forms of the parasite. We concluded that a nitrate reductase activity produce NO and NO-derived RNS in or around the food vacuole in P. falciparum parasites. The food vacuole is a critical parasitic compartment involved in hemoglobin degradation, heme detoxification and a target for antimalarial drug action. Characterization of this relatively unexplored synthetic activity could provide important clues into poorly understood metabolic processes of the malaria parasite, PMID:18504040

  6. Evidence that the Malaria Parasite Plasmodium falciparum Putative Rhoptry Protein 2 Localizes to the Golgi Apparatus throughout the Erythrocytic Cycle.

    PubMed

    Hallée, Stéphanie; Richard, Dave

    2015-01-01

    Invasion of a red blood cell by Plasmodium falciparum merozoites is an essential step in the malaria lifecycle. Several of the proteins involved in this process are stored in the apical complex of the merozoite, a structure containing secretory organelles that are released at specific times during invasion. The molecular players involved in erythrocyte invasion thus represent potential key targets for both therapeutic and vaccine-based strategies to block parasite development. In our quest to identify and characterize new effectors of invasion, we investigated the P. falciparum homologue of a P. berghei protein putatively localized to the rhoptries, the Putative rhoptry protein 2 (PbPRP2). We show that in P. falciparum, the protein colocalizes extensively with the Golgi apparatus across the asexual erythrocytic cycle. Furthermore, imaging of merozoites caught at different times during invasion show that PfPRP2 is not secreted during the process instead staying associated with the Golgi apparatus. Our evidence therefore suggests that PfPRP2 is a Golgi protein and that it is likely not a direct effector in the process of merozoite invasion.

  7. Enhancing community detection by using local structural information

    NASA Astrophysics Data System (ADS)

    Xiang, Ju; Hu, Ke; Zhang, Yan; Bao, Mei-Hua; Tang, Liang; Tang, Yan-Ni; Gao, Yuan-Yuan; Li, Jian-Ming; Chen, Benyan; Hu, Jing-Bo

    2016-03-01

    Many real-world networks, such as gene networks, protein-protein interaction networks and metabolic networks, exhibit community structures, meaning the existence of groups of densely connected vertices in the networks. Many local similarity measures in the networks are closely related to the concept of the community structures, and may have a positive effect on community detection in the networks. Here, various local similarity measures are used to extract local structural information, which is then applied to community detection in the networks by using the edge-reweighting strategy. The effect of the local similarity measures on community detection is carefully investigated and compared in various networks. The experimental results show that the local similarity measures are crucial for the improvement of community detection methods, while the positive effect of the local similarity measures is closely related to the networks under study and applied community detection methods.

  8. A Motion Detection Algorithm Using Local Phase Information

    PubMed Central

    Lazar, Aurel A.; Ukani, Nikul H.; Zhou, Yiyin

    2016-01-01

    Previous research demonstrated that global phase alone can be used to faithfully represent visual scenes. Here we provide a reconstruction algorithm by using only local phase information. We also demonstrate that local phase alone can be effectively used to detect local motion. The local phase-based motion detector is akin to models employed to detect motion in biological vision, for example, the Reichardt detector. The local phase-based motion detection algorithm introduced here consists of two building blocks. The first building block measures/evaluates the temporal change of the local phase. The temporal derivative of the local phase is shown to exhibit the structure of a second order Volterra kernel with two normalized inputs. We provide an efficient, FFT-based algorithm for implementing the change of the local phase. The second processing building block implements the detector; it compares the maximum of the Radon transform of the local phase derivative with a chosen threshold. We demonstrate examples of applying the local phase-based motion detection algorithm on several video sequences. We also show how the locally detected motion can be used for segmenting moving objects in video scenes and compare our local phase-based algorithm to segmentation achieved with a widely used optic flow algorithm. PMID:26880882

  9. Development of a Multiplex PCR-Ligase Detection Reaction Assay for Diagnosis of Infection by the Four Parasite Species Causing Malaria in Humans

    PubMed Central

    McNamara, David T.; Thomson, Jodi M.; Kasehagen, Laurin J.; Zimmerman, Peter A.

    2004-01-01

    The diagnosis of infections caused by Plasmodium species is critical for understanding the nature of malarial disease, treatment efficacy, malaria control, and public health. The demands of field-based epidemiological studies of malaria will require faster and more sensitive diagnostic methods as new antimalarial drugs and vaccines are explored. We have developed a multiplex PCR-ligase detection reaction (LDR) assay that allows the simultaneous diagnosis of infection by all four parasite species causing malaria in humans. This assay exhibits sensitivity and specificity equal to those of other PCR-based assays, identifying all four human malaria parasite species at levels of parasitemias equal to 1 parasitized erythrocyte/μl of blood. The multiplex PCR-LDR assay goes beyond other PCR-based assays by reducing technical procedures and by detecting intraindividual differences in species-specific levels of parasitemia. Application of the multiplex PCR-LDR assay will provide the sensitivity and specificity expected of PCR-based diagnostic assays and will contribute new insight regarding relationships between the human malaria parasite species and the human host in future epidemiological studies. PMID:15184411

  10. Development of a multiplex PCR-ligase detection reaction assay for diagnosis of infection by the four parasite species causing malaria in humans.

    PubMed

    McNamara, David T; Thomson, Jodi M; Kasehagen, Laurin J; Zimmerman, Peter A

    2004-06-01

    The diagnosis of infections caused by Plasmodium species is critical for understanding the nature of malarial disease, treatment efficacy, malaria control, and public health. The demands of field-based epidemiological studies of malaria will require faster and more sensitive diagnostic methods as new antimalarial drugs and vaccines are explored. We have developed a multiplex PCR-ligase detection reaction (LDR) assay that allows the simultaneous diagnosis of infection by all four parasite species causing malaria in humans. This assay exhibits sensitivity and specificity equal to those of other PCR-based assays, identifying all four human malaria parasite species at levels of parasitemias equal to 1 parasitized erythrocyte/microl of blood. The multiplex PCR-LDR assay goes beyond other PCR-based assays by reducing technical procedures and by detecting intraindividual differences in species-specific levels of parasitemia. Application of the multiplex PCR-LDR assay will provide the sensitivity and specificity expected of PCR-based diagnostic assays and will contribute new insight regarding relationships between the human malaria parasite species and the human host in future epidemiological studies.

  11. Entomological Monitoring and Evaluation: Diverse Transmission Settings of ICEMR Projects Will Require Local and Regional Malaria Elimination Strategies.

    PubMed

    Conn, Jan E; Norris, Douglas E; Donnelly, Martin J; Beebe, Nigel W; Burkot, Thomas R; Coulibaly, Mamadou B; Chery, Laura; Eapen, Alex; Keven, John B; Kilama, Maxwell; Kumar, Ashwani; Lindsay, Steve W; Moreno, Marta; Quinones, Martha; Reimer, Lisa J; Russell, Tanya L; Smith, David L; Thomas, Matthew B; Walker, Edward D; Wilson, Mark L; Yan, Guiyun

    2015-09-01

    The unprecedented global efforts for malaria elimination in the past decade have resulted in altered vectorial systems, vector behaviors, and bionomics. These changes combined with increasingly evident heterogeneities in malaria transmission require innovative vector control strategies in addition to the established practices of long-lasting insecticidal nets and indoor residual spraying. Integrated vector management will require focal and tailored vector control to achieve malaria elimination. This switch of emphasis from universal coverage to universal coverage plus additional interventions will be reliant on improved entomological monitoring and evaluation. In 2010, the National Institutes for Allergies and Infectious Diseases (NIAID) established a network of malaria research centers termed ICEMRs (International Centers for Excellence in Malaria Research) expressly to develop this evidence base in diverse malaria endemic settings. In this article, we contrast the differing ecology and transmission settings across the ICEMR study locations. In South America, Africa, and Asia, vector biologists are already dealing with many of the issues of pushing to elimination such as highly focal transmission, proportionate increase in the importance of outdoor and crepuscular biting, vector species complexity, and "sub patent" vector transmission.

  12. Entomological Monitoring and Evaluation: Diverse Transmission Settings of ICEMR Projects Will Require Local and Regional Malaria Elimination Strategies

    PubMed Central

    Conn, Jan E.; Norris, Douglas E.; Donnelly, Martin J.; Beebe, Nigel W.; Burkot, Thomas R.; Coulibaly, Mamadou B.; Chery, Laura; Eapen, Alex; Keven, John B.; Kilama, Maxwell; Kumar, Ashwani; Lindsay, Steve W.; Moreno, Marta; Quinones, Martha; Reimer, Lisa J.; Russell, Tanya L.; Smith, David L.; Thomas, Matthew B.; Walker, Edward D.; Wilson, Mark L.; Yan, Guiyun

    2015-01-01

    The unprecedented global efforts for malaria elimination in the past decade have resulted in altered vectorial systems, vector behaviors, and bionomics. These changes combined with increasingly evident heterogeneities in malaria transmission require innovative vector control strategies in addition to the established practices of long-lasting insecticidal nets and indoor residual spraying. Integrated vector management will require focal and tailored vector control to achieve malaria elimination. This switch of emphasis from universal coverage to universal coverage plus additional interventions will be reliant on improved entomological monitoring and evaluation. In 2010, the National Institutes for Allergies and Infectious Diseases (NIAID) established a network of malaria research centers termed ICEMRs (International Centers for Excellence in Malaria Research) expressly to develop this evidence base in diverse malaria endemic settings. In this article, we contrast the differing ecology and transmission settings across the ICEMR study locations. In South America, Africa, and Asia, vector biologists are already dealing with many of the issues of pushing to elimination such as highly focal transmission, proportionate increase in the importance of outdoor and crepuscular biting, vector species complexity, and “sub patent” vector transmission. PMID:26259942

  13. Prokaryotic ancestry and gene fusion of a dual localized peroxiredoxin in malaria parasites

    PubMed Central

    Djuika, Carine F.; Huerta-Cepas, Jaime; Przyborski, Jude M.; Deil, Sophia; Sanchez, Cecilia P.; Doerks, Tobias; Bork, Peer; Lanzer, Michael; Deponte, Marcel

    2015-01-01

    Horizontal gene transfer has emerged as a crucial driving force for the evolution of eukaryotes. This also includes Plasmodium falciparum and related economically and clinically relevant apicomplexan parasites, whose rather small genomes have been shaped not only by natural selection in different host populations but also by horizontal gene transfer following endosymbiosis. However, there is rather little reliable data on horizontal gene transfer between animal hosts or bacteria and apicomplexan parasites. Here we show that apicomplexan homologues of peroxiredoxin 5 (Prx5) have a prokaryotic ancestry and therefore represent a special subclass of Prx5 isoforms in eukaryotes. Using two different immunobiochemical approaches, we found that the P. falciparum Prx5 homologue is dually localized to the parasite plastid and cytosol. This dual localization is reflected by a modular Plasmodium-specific gene architecture consisting of two exons. Despite the plastid localization, our phylogenetic analyses contradict an acquisition by secondary endosymbiosis and support a gene fusion event following a horizontal prokaryote-to-eukaryote gene transfer in early apicomplexans. The results provide unexpected insights into the evolution of apicomplexan parasites as well as the molecular evolution of peroxiredoxins, an important family of ubiquitous, usually highly concentrated thiol-dependent hydroperoxidases that exert functions as detoxifying enzymes, redox sensors and chaperones. PMID:28357258

  14. A Novel Xenomonitoring Technique Using Mosquito Excreta/Feces for the Detection of Filarial Parasites and Malaria

    PubMed Central

    Pilotte, Nils; Zaky, Weam I.; Abrams, Brian P.; Chadee, Dave D.; Williams, Steven A.

    2016-01-01

    Background Given the continued successes of the world’s lymphatic filariasis (LF) elimination programs and the growing successes of many malaria elimination efforts, the necessity of low cost tools and methodologies applicable to long-term disease surveillance is greater than ever before. As many countries reach the end of their LF mass drug administration programs and a growing number of countries realize unprecedented successes in their malaria intervention efforts, the need for practical molecular xenomonitoring (MX), capable of providing surveillance for disease recrudescence in settings of decreased parasite prevalence is increasingly clear. Current protocols, however, require testing of mosquitoes in pools of 25 or fewer, making high-throughput examination a challenge. The new method we present here screens the excreta/feces from hundreds of mosquitoes per pool and provides proof-of-concept for a practical alternative to traditional methodologies resulting in significant cost and labor savings. Methodology/Principal Findings Excreta/feces of laboratory reared Aedes aegypti or Anopheles stephensi mosquitoes provided with a Brugia malayi microfilaria-positive or Plasmodium vivax-positive blood meal respectively were tested for the presence of parasite DNA using real-time PCR. A titration of samples containing various volumes of B. malayi-negative mosquito feces mixed with positive excreta/feces was also tested to determine sensitivity of detection. Real-time PCR amplification of B. malayi and P. vivax DNA from the excreta/feces of infected mosquitoes was demonstrated, and B. malayi DNA in excreta/feces from one to two mf-positive blood meal-receiving mosquitoes was detected when pooled with volumes of feces from as many as 500 uninfected mosquitoes. Conclusions/Significance While the operationalizing of excreta/feces testing may require the development of new strategies for sample collection, the high-throughput nature of this new methodology has the

  15. Determination of Malaria Epidemiological Status in Iran’s Malarious Areas as Baseline Information for Implementation of Malaria Elimination Program in Iran

    PubMed Central

    RAEISI, Ahmad; GOUYA, Mohammad Mehdi; NADIM, Abolhassan; RANJBAR, Mansour; HASANZEHI, Abdolghafar; FALLAHNEZHAD, Mojtaba; SAKENI, Mohammad; SAFARI, Reza; SAFFARI, Mehdi; MASHYEKHI, Minoo; AHMADI KAHNALI, Assadalah; MIRKHANI, Vahid; ALMASIAN, Elham; Faraji, Leila; PAKTINAT JALALI, Bita; NIKPOUR, Fatemeh

    2013-01-01

    Background According to willingness of the Ministry of Health, Iran and presence of appropriate conditions for disease elimination, national malaria control program decided to conduct a research to clarify malaria status in 2007 and to provide required information to perform the elimination program. This review is comprised of the basis of national malaria elimination program in vision of 2025, which was started in 2010. Methods: In this descriptive study, data were analyzed by applications of different variables at district level. All districts in the three south eastern provinces, in which malaria has local transmission, were considered. Malaria cases has been determined and studied based on the national malaria surveillance system. Results: Since vivax malaria is predominant in Sistan & Baluchestan Province, number of vivax cases is equal to malaria positive cases approximately. The important point is that Nikshahr contains the maximum number of local vivax cases in this province and the maximum number of falciparum cases is reported from Sarbaz district. Among all districts of Hormozgan Province, no case of autochthonous falciparum was detected except in Bandar Jask and one case in Minab. There was no case of autochthonous falciparum in Kerman Province, except in Kahnoj and Ghale Ganj that each of them had one case in 2007. Conclusion: It appears that the report of locally transmitted cases in Iran is increasing over the past few years, before starting malaria elimination plan. Since the Afghan refugees started to return to their own country so the main source of reporting of imported malaria cases reduced and local cases would be demonstrated more clearly. PMID:23641411

  16. Active testing for face detection and localization.

    PubMed

    Sznitman, Raphael; Jedynak, Bruno

    2010-10-01

    We provide a novel search technique which uses a hierarchical model and a mutual information gain heuristic to efficiently prune the search space when localizing faces in images. We show exponential gains in computation over traditional sliding window approaches, while keeping similar performance levels.

  17. Detecting local haplotype sharing and haplotype association

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel haplotype association method is presented, and its power is demonstrated. Relying on a statistical model for linkage disequilibrium (LD), the method first infers ancestral haplotypes and their loadings at each marker for each individual. The loadings are then used to quantify local haplotype...

  18. Effect of Early Detection and Treatment on Malaria Related Maternal Mortality on the North-Western Border of Thailand 1986–2010

    PubMed Central

    McGready, Rose; Boel, Machteld; Rijken, Marcus J.; Ashley, Elizabeth A.; Cho, Thein; Moo, Oh; Paw, Moo Koh; Pimanpanarak, Mupawjay; Hkirijareon, Lily; Carrara, Verena I.; Lwin, Khin Maung; Phyo, Aung Pyae; Turner, Claudia; Chu, Cindy S.; van Vugt, Michele; Price, Richard N.; Luxemburger, Christine; ter Kuile, Feiko O.; Tan, Saw Oo; Proux, Stephane; Singhasivanon, Pratap; White, Nicholas J.; Nosten, François H.

    2012-01-01

    Introduction Maternal mortality is high in developing countries, but there are few data in high-risk groups such as migrants and refugees in malaria-endemic areas. Trends in maternal mortality were followed over 25 years in antenatal clinics prospectively established in an area with low seasonal transmission on the north-western border of Thailand. Methods and Findings All medical records from women who attended the Shoklo Malaria Research Unit antenatal clinics from 12th May 1986 to 31st December 2010 were reviewed, and maternal death records were analyzed for causality. There were 71 pregnancy-related deaths recorded amongst 50,981 women who attended antenatal care at least once. Three were suicide and excluded from the analysis as incidental deaths. The estimated maternal mortality ratio (MMR) overall was 184 (95%CI 150–230) per 100,000 live births. In camps for displaced persons there has been a six-fold decline in the MMR from 499 (95%CI 200–780) in 1986–90 to 79 (40–170) in 2006–10, p<0.05. In migrants from adjacent Myanmar the decline in MMR was less significant: 588 (100–3260) to 252 (150–430) from 1996–2000 to 2006–2010. Mortality from P.falciparum malaria in pregnancy dropped sharply with the introduction of systematic screening and treatment and continued to decline with the reduction in the incidence of malaria in the communities. P.vivax was not a cause of maternal death in this population. Infection (non-puerperal sepsis and P.falciparum malaria) accounted for 39.7 (27/68) % of all deaths. Conclusions Frequent antenatal clinic screening allows early detection and treatment of falciparum malaria and substantially reduces maternal mortality from P.falciparum malaria. No significant decline has been observed in deaths from sepsis or other causes in refugee and migrant women on the Thai–Myanmar border. PMID:22815732

  19. Malaria elimination in Isabel Province, Solomon Islands: establishing a surveillance-response system to prevent introduction and reintroduction of malaria

    PubMed Central

    2011-01-01

    Background The Solomon Islands National Malaria Programme is currently focused on intensified control and progressive elimination. Recent control efforts in Isabel Province have reduced their malaria incidence to 2.6/1,000 population in 2009 [1] whereas most neighbouring provinces have much higher incidences. A malaria surveillance-response system that involves testing all travellers entering Isabel Province using rapid diagnostic tests (RDT) to prevent cases being imported had been proposed by local health authorities. This study provides information on the feasibility and acceptability of implementing a new approach of surveillance and response in the context of low levels of indigenous malaria transmission in Isabel Province. Methods A total of 13 focus group discussions (FGD) and 22 key informant interviews (KII) were conducted in Isabel Province, Solomon Islands. Key topics included: the travel patterns of people to, from and within Isabel Province; the acceptability, community perceptions, attitudes and suggestions towards the proposed surveillance programme; and management of suspected malaria cases. This information was triangulated with data obtained from port authorities, airlines and passenger ships travelling to and from Isabel Province in the preceding two years. Results Travel within Isabel Province and to and from other provinces is common with marked seasonality. The majority of inter-provincial travel is done on scheduled public transport; namely passenger ships and aircrafts. In Isabel Province there is a healthy community spirit as well as high concern regarding malaria and its importation and there is currently effective malaria passive case detection and management. Conducting malaria screening at ports and airports would be acceptable to the community. Conclusion A robust surveillance-response system is essential when moving towards malaria elimination. Many factors contribute positively towards the feasibility of an RDT based malaria

  20. Detection, Classification, and Localization Workshop 2011

    DTIC Science & Technology

    2011-09-30

    The Fourth International Conference on Detection and Classification of Marine Mammals using Passive Acoustics ( Pavia , Italy, 2009) • The...International BioAcoustic Congress ( Pavia , Italy, 2009) The workshop was also announced through postings to these electronic mailing lists: • the

  1. Homology blocks of Plasmodium falciparum var genes and clinically distinct forms of severe malaria in a local population

    PubMed Central

    2013-01-01

    Background The primary target of the human immune response to the malaria parasite Plasmodium falciparum, P. falciparum erythrocyte membrane protein 1 (PfEMP1), is encoded by the members of the hyper-diverse var gene family. The parasite exhibits antigenic variation via mutually exclusive expression (switching) of the ~60 var genes within its genome. It is thought that different variants exhibit different host endothelial binding preferences that in turn result in different manifestations of disease. Results Var sequences comprise ancient sequence fragments, termed homology blocks (HBs), that recombine at exceedingly high rates. We use HBs to define distinct var types within a local population. We then reanalyze a dataset that contains clinical and var expression data to investigate whether the HBs allow for a description of sequence diversity corresponding to biological function, such that it improves our ability to predict disease phenotype from parasite genetics. We find that even a generic set of HBs, which are defined for a small number of non-local parasites: capture the majority of local sequence diversity; improve our ability to predict disease severity from parasite genetics; and reveal a previously hypothesized yet previously unobserved parasite genetic basis for two forms of severe disease. We find that the expression rates of some HBs correlate more strongly with severe disease phenotypes than the expression rates of classic var DBLα tag types, and principal components of HB expression rate profiles further improve genotype-phenotype models. More specifically, within the large Kenyan dataset that is the focus of this study, we observe that HB expression differs significantly for severe versus mild disease, and for rosetting versus impaired consciousness associated severe disease. The analysis of a second much smaller dataset from Mali suggests that these HB-phenotype associations are consistent across geographically distant populations, since we find

  2. Malaria outbreak in a malaria-free region in Oman 1998: unknown impact of civil war in Africa.

    PubMed

    Baomar, A; Mohamed, A

    2000-11-01

    Beginning in April 1998, the surveillance system in Dhofar region, Oman, detected malaria cases among individuals who had no risk factors for the acquisition of malaria. An investigation was conducted to describe the outbreak and to identify its possible causes. A malaria case was defined as an unexplained fever (>38 degrees C) in a resident of the Dhofar region from April to September 1998. The investigation consisted of enhanced passive case detection, active case finding through contact screening, mass blood survey and school survey. Also an entomological survey was conducted and meteorological data was reviewed. Over a period of seven months, 1279 patients with fever were examined for malaria parasites. Sixty-five cases were positive; 60 (92%) males and 5 (8%) females. Cases occurred in all age groups (range: 2-63 years, median 25 years). Most cases were among illegal Somali immigrants (28, 43%) followed by Omanis (20, 31%). Out of the 2323 slides collected from the community and 2487 from school children, 21 slides were positive. All of them were from illegal immigrants. The entomological survey detected three vectors, previously found in the region: A. d'thali, A. sergenti and A. stephensi. Although the region is classified as a malaria-free region, it has the potential for malaria introduction. This outbreak most likely occurred due to the influx of hundreds of illegal Somali immigrants due to the civil war into the Dhofar region, providing a sufficient number of gametocyte carriers for local anopheline mosquitoes to feed on.

  3. Local modularity for community detection in complex networks

    NASA Astrophysics Data System (ADS)

    Xiang, Ju; Hu, Tao; Zhang, Yan; Hu, Ke; Li, Jian-Ming; Xu, Xiao-Ke; Liu, Cui-Cui; Chen, Shi

    2016-02-01

    Community detection is a topic of interest in the study of complex networks such as the protein-protein interaction networks and metabolic networks. In recent years, various methods were proposed to detect community structures of the networks. Here, a kind of local modularity with tunable parameter is derived from the Newman-Girvan modularity by a special self-loop strategy that depends on the community division of the networks. By the self-loop strategy, one can easily control the definition of modularity, and the resulting modularity can be optimized by using the existing modularity optimization algorithms. The local modularity is used as the target function for community detection, and a self-consistent method is proposed for the optimization of the local modularity. We analyze the behaviors of the local modularity and show the validity of the local modularity in detecting community structures on various networks.

  4. [Malaria in Algerian Sahara].

    PubMed

    Hammadi, D; Boubidi, S C; Chaib, S E; Saber, A; Khechache, Y; Gasmi, M; Harrat, Z

    2009-08-01

    Thanks to the malaria eradication campaign launched in Algeria in 1968, the number of malaria cases fell down significantly from 95,424 cases in 1960 to 30 cases in 1978. At that time the northern part of the country was declared free of Plasmodium falciparum. Only few cases belonging to P. vivax persisted in residual foci in the middle part of the country. In the beginning of the eighties, the south of the country was marked by an increase of imported malaria cases. The resurgence of the disease in the oases coincided with the opening of the Trans-Saharan road and the booming trade with the neighbouring southern countries. Several authors insisted on the risk of introduction of malaria or its exotic potential vectors in Algeria via this new road. Now, the totality of malaria autochthonous cases in Algeria are located in the south of the country where 300 cases were declared during the period (1980-2007). The recent outbreak recorded in 2007 at the borders with Mall and the introduction of Anopheles gambiae into the Algerian territory show the vulnerability of this area to malaria which is probably emphasized by the local environmental changes. The authors assess the evolution of malaria in the Sahara region and draw up the distribution of the anopheles in this area.

  5. Species concepts and malaria parasites: detecting a cryptic species of Plasmodium.

    PubMed Central

    Perkins, S L

    2000-01-01

    Species of malaria parasite (phylum Apicomplexa: genus Plasmodium) have traditionally been described using the similarity species concept (based primarily on differences in morphological or life-history characteristics). The biological species concept (reproductive isolation) and phylogenetic species concept (based on monophyly) have not been used before in defining species of Plasmodium. Plasmodium azurophilum, described from Anolis lizards in the eastern Caribbean, is actually a two-species cryptic complex. The parasites were studied from eight islands, from Puerto Rico in the north to Grenada in the south. Morphology of the two species is very similar (differences are indistinguishable to the eye), but one infects only erythrocytes and the other only white blood cells. Molecular data for the cytochrome b gene reveal that the two forms are reproductively isolated; distinct haplotypes are present on each island and are never shared between the erythrocyte-infecting and leucocyte-infecting species. Each forms a monophyletic lineage indicating that they diverged before becoming established in the anoles of the eastern Caribbean. This comparison of the similarity, biological and phylogenetic species concepts for malaria parasites reveals the limited value of using only similarity measures in defining protozoan species. PMID:11413654

  6. SYBR Green real-time PCR-RFLP assay targeting the plasmodium cytochrome B gene--a highly sensitive molecular tool for malaria parasite detection and species determination.

    PubMed

    Xu, Weiping; Morris, Ulrika; Aydin-Schmidt, Berit; Msellem, Mwinyi I; Shakely, Delér; Petzold, Max; Björkman, Anders; Mårtensson, Andreas

    2015-01-01

    A prerequisite for reliable detection of low-density Plasmodium infections in malaria pre-elimination settings is the availability of ultra-sensitive and high-throughput molecular tools. We developed a SYBR Green real-time PCR restriction fragment length polymorphism assay (cytb-qPCR) targeting the cytochrome b gene of the four major human Plasmodium species (P. falciparum, P. vivax, P. malariae, and P. ovale) for parasite detection and species determination with DNA extracted from dried blood spots collected on filter paper. The performance of cytb-qPCR was first compared against four reference PCR methods using serially diluted Plasmodium samples. The detection limit of the cytb-qPCR was 1 parasite/μl (p/μl) for P. falciparum and P. ovale, and 2 p/μl for P. vivax and P. malariae, while the reference PCRs had detection limits of 0.5-10 p/μl. The ability of the PCR methods to detect low-density Plasmodium infections was then assessed using 2977 filter paper samples collected during a cross-sectional survey in Zanzibar, a malaria pre-elimination setting in sub-Saharan Africa. Field samples were defined as 'final positive' if positive in at least two of the five PCR methods. Cytb-qPCR preformed equal to or better than the reference PCRs with a sensitivity of 100% (65/65; 95%CI 94.5-100%) and a specificity of 99.9% (2910/2912; 95%CI 99.7-100%) when compared against 'final positive' samples. The results indicate that the cytb-qPCR may represent an opportunity for improved molecular surveillance of low-density Plasmodium infections in malaria pre-elimination settings.

  7. [Malaria in the Rostov Region: retrospective analysis of the malaria situation in 1952-2007].

    PubMed

    Kormilenko, I V; Aĭdinov, G T; Shvager, M M

    2009-01-01

    In the Rostov Region, no cases of local malaria transmission have been notified since 1958, but cases of import malaria are recorded every year. The region is one of malaria-susceptible areas in the Russian Federation, which is characterized by intensive migration, the malariogenic potential sufficient for local transmission (malariogenic index 1.2), and the optimum conditions for resurgence of malaria when it is imported. The prevention of undesirable consequences of malaria importation requires the strict monitoring of feverish patients, cohorts of high-risk patients who go for trips to malaria-endemic countries.

  8. High and Heterogeneous Prevalence of Asymptomatic and Sub-microscopic Malaria Infections on Islands in Lake Victoria, Kenya

    PubMed Central

    Idris, Zulkarnain Md; Chan, Chim W.; Kongere, James; Gitaka, Jesse; Logedi, John; Omar, Ahmeddin; Obonyo, Charles; Machini, Beatrice Kemunto; Isozumi, Rie; Teramoto, Isao; Kimura, Masatsugu; Kaneko, Akira

    2016-01-01

    Kenya is intensifying its national efforts in malaria control to achieve malaria elimination. Detailed characterization of malaria infection among populations living in the areas where the disease is endemic in Kenya is a crucial priority, especially for planning and evaluating future malaria elimination strategy. This study aimed to investigate the distribution and extent of malaria infection on islands in Lake Victoria of Kenya to aid in designing new interventions for malaria elimination. Five cross-sectional surveys were conducted between January 2012 and August 2014 on four islands (Mfangano, Takawiri, Kibuogi and Ngodhe) in Lake Victoria and a coastal mainland (Ungoye). Malaria prevalence varied significantly among settings: highest in Ungoye, followed by the large island of Mfangano and lowest in the three remaining small islands. Of the 3867 malaria infections detected by PCR, 91.8% were asymptomatic, 50.3% were sub-microscopic, of which 94% were also asymptomatic. We observed geographical differences and age dependency in both proportion of sub-microscopic infections and asymptomatic parasite carriage. Our findings highlighted the local heterogeneity in malaria prevalence on islands and a coastal area in Lake Victoria, and provided support for the inclusion of mass drug administration as a component of the intervention package to eliminate malaria on islands. PMID:27841361

  9. High and Heterogeneous Prevalence of Asymptomatic and Sub-microscopic Malaria Infections on Islands in Lake Victoria, Kenya.

    PubMed

    Idris, Zulkarnain Md; Chan, Chim W; Kongere, James; Gitaka, Jesse; Logedi, John; Omar, Ahmeddin; Obonyo, Charles; Machini, Beatrice Kemunto; Isozumi, Rie; Teramoto, Isao; Kimura, Masatsugu; Kaneko, Akira

    2016-11-14

    Kenya is intensifying its national efforts in malaria control to achieve malaria elimination. Detailed characterization of malaria infection among populations living in the areas where the disease is endemic in Kenya is a crucial priority, especially for planning and evaluating future malaria elimination strategy. This study aimed to investigate the distribution and extent of malaria infection on islands in Lake Victoria of Kenya to aid in designing new interventions for malaria elimination. Five cross-sectional surveys were conducted between January 2012 and August 2014 on four islands (Mfangano, Takawiri, Kibuogi and Ngodhe) in Lake Victoria and a coastal mainland (Ungoye). Malaria prevalence varied significantly among settings: highest in Ungoye, followed by the large island of Mfangano and lowest in the three remaining small islands. Of the 3867 malaria infections detected by PCR, 91.8% were asymptomatic, 50.3% were sub-microscopic, of which 94% were also asymptomatic. We observed geographical differences and age dependency in both proportion of sub-microscopic infections and asymptomatic parasite carriage. Our findings highlighted the local heterogeneity in malaria prevalence on islands and a coastal area in Lake Victoria, and provided support for the inclusion of mass drug administration as a component of the intervention package to eliminate malaria on islands.

  10. Mapping residual transmission for malaria elimination.

    PubMed

    Reiner, Robert C; Le Menach, Arnaud; Kunene, Simon; Ntshalintshali, Nyasatu; Hsiang, Michelle S; Perkins, T Alex; Greenhouse, Bryan; Tatem, Andrew J; Cohen, Justin M; Smith, David L

    2015-12-29

    Eliminating malaria from a defined region involves draining the endemic parasite reservoir and minimizing local malaria transmission around imported malaria infections . In the last phases of malaria elimination, as universal interventions reap diminishing marginal returns, national resources must become increasingly devoted to identifying where residual transmission is occurring. The needs for accurate measures of progress and practical advice about how to allocate scarce resources require new analytical methods to quantify fine-grained heterogeneity in malaria risk. Using routine national surveillance data from Swaziland (a sub-Saharan country on the verge of elimination), we estimated individual reproductive numbers. Fine-grained maps of reproductive numbers and local malaria importation rates were combined to show 'malariogenic potential', a first for malaria elimination. As countries approach elimination, these individual-based measures of transmission risk provide meaningful metrics for planning programmatic responses and prioritizing areas where interventions will contribute most to malaria elimination.

  11. Smart sensing skin for detection and localization of fatigue cracks

    NASA Astrophysics Data System (ADS)

    Kharroub, Sari; Laflamme, Simon; Song, Chunhui; Qiao, Daji; Phares, Brent; Li, Jian

    2015-06-01

    Fatigue cracks on steel components may have strong consequences on the structure’s serviceability and strength. Their detection and localization is a difficult task. Existing technologies enabling structural health monitoring have a complex link signal-to-damage or have economic barriers impeding large-scale deployment. A solution is to develop sensing methods that are inexpensive, scalable, with signals that can directly relate to damage. The authors have recently proposed a smart sensing skin for structural health monitoring applications to mesosystems. The sensor is a thin film soft elastomeric capacitor (SEC) that transduces strain into a measurable change in capacitance. Arranged in a network configuration, the SEC would have the capacity to detect and localize damage by detecting local deformation over a global surface, analogous to biological skin. In this paper, the performance of the SEC at detecting and localizing fatigue cracks in steel structures is investigated. Fatigue cracks are induced in steel specimens equipped with SECs, and data measured continuously. Test results show that the fatigue crack can be detected at an early stage. The smallest detectable crack length and width are 27.2 and 0.254 mm, respectively, and the average detectable crack length and width are 29.8 and 0.432 mm, respectively. Results also show that, when used in a network configuration, only the sensor located over the formed fatigue crack detect the damage, thus validating the capacity of the SEC at damage localization.

  12. Diagnosing infection levels of four human malaria parasite species by a polymerase chain reaction/ligase detection reaction fluorescent microsphere-based assay.

    PubMed

    McNamara, David T; Kasehagen, Laurin J; Grimberg, Brian T; Cole-Tobian, Jennifer; Collins, William E; Zimmerman, Peter A

    2006-03-01

    Improving strategies for diagnosing infection by the four human Plasmodium species parasites is important as field-based epidemiologic and clinical studies focused on malaria become more ambitious. Expectations for malaria diagnostic assays include rapid processing with minimal expertise, very high specificity and sensitivity, and quantitative evaluation of parasitemia to be delivered at a very low cost. Toward fulfilling many of these expectations, we have developed a post-polymerase chain reaction (PCR)/ligase detection reaction-fluorescent microsphere assay (LDR-FMA). This assay, which uses Luminex FlexMAP microspheres, provides simultaneous, semi-quantitative detection of infection by all four human malaria parasite species at a sensitivity and specificity equal to other PCR-based assays. In blinded studies using P. falciparum-infected blood from in vitro cultures, we identified infected and uninfected samples with 100% concordance. Additionally, in analyses of P. falciparum in vitro cultures and P. vivax-infected monkeys, comparisons between parasitemia and LDR-FMA signal intensity showed very strong positive correlations (r > 0.95). Application of this multiplex Plasmodium species LDR-FMA diagnostic assay will increase the speed, accuracy, and reliability of diagnosing human Plasmodium species infections in epidemiologic studies of complex malaria-endemic settings.

  13. Comparative performance of the ParaSight F test for detection of Plasmodium falciparum in malaria-immune and nonimmune populations in Irian Jaya, Indonesia.

    PubMed Central

    Fryauff, D. J.; Gomez-Saladin, E.; Purnomo; Sumawinata, I.; Sutamihardja, M. A.; Tuti, S.; Subianto, B.; Richie, T. L.

    1997-01-01

    A comparison was made of the performance of the ParaSight F test (F test) for detection of Plasmodium falciparum in blood from malaria-immune (410 native Irianese) and nonimmune (369 new transmigrants) populations in Irian Jaya, Indonesia, where malaria is hyperendemic and all four species of human malaria occur. There were highly significant differences between populations in the sensitivity (Irianese, 60% versus transmigrants, 84%; P < 0.001) and specificity (Irianese, 97% versus transmigrants, 84%; P < 0.001) of the F test. The test had comparably high levels of sensitivity for Irianese children aged < or = 10 years, both age groups of transmigrants (76-85%), but low sensitivity for Irianese aged > 10 years (40%), among whom only 7% of parasitaemias < 120 per microliter and 69% of those > 120 per microliter were detected. Specificity was comparably high for transmigrant children aged < or = 10 years and both age groups of Irianese (93-98%). The low specificity for transmigrants aged > 10 years (79%) was due to a preponderance of false positives, frequently identified by microscopy as P. vivax. The results suggest that comparison based on microscopy underestimated the performance of the ParaSight F test and that malaria immune status, irrespective of P. falciparum density, may influence the test's sensitivity. PMID:9509627

  14. Sensitive Detection of Plasmodium vivax Using a High-Throughput, Colourimetric Loop Mediated Isothermal Amplification (HtLAMP) Platform: A Potential Novel Tool for Malaria Elimination

    PubMed Central

    Britton, Sumudu; Cheng, Qin; Grigg, Matthew J.; Poole, Catherine B.; Pasay, Cielo; William, Timothy; Fornace, Kimberley; Anstey, Nicholas M.; Sutherland, Colin J.; Drakeley, Chris; McCarthy, James S.

    2016-01-01

    Introduction Plasmodium vivax malaria has a wide geographic distribution and poses challenges to malaria elimination that are likely to be greater than those of P. falciparum. Diagnostic tools for P. vivax infection in non-reference laboratory settings are limited to microscopy and rapid diagnostic tests but these are unreliable at low parasitemia. The development and validation of a high-throughput and sensitive assay for P. vivax is a priority. Methods A high-throughput LAMP assay targeting a P. vivax mitochondrial gene and deploying colorimetric detection in a 96-well plate format was developed and evaluated in the laboratory. Diagnostic accuracy was compared against microscopy, antigen detection tests and PCR and validated in samples from malaria patients and community controls in a district hospital setting in Sabah, Malaysia. Results The high throughput LAMP-P. vivax assay (HtLAMP-Pv) performed with an estimated limit of detection of 1.4 parasites/ μL. Assay primers demonstrated cross-reactivity with P. knowlesi but not with other Plasmodium spp. Field testing of HtLAMP-Pv was conducted using 149 samples from symptomatic malaria patients (64 P. vivax, 17 P. falciparum, 56 P. knowlesi, 7 P. malariae, 1 mixed P. knowlesi/P. vivax, with 4 excluded). When compared against multiplex PCR, HtLAMP-Pv demonstrated a sensitivity for P. vivax of 95% (95% CI 87–99%); 61/64), and specificity of 100% (95% CI 86–100%); 25/25) when P. knowlesi samples were excluded. HtLAMP-Pv testing of 112 samples from asymptomatic community controls, 7 of which had submicroscopic P. vivax infections by PCR, showed a sensitivity of 71% (95% CI 29–96%; 5/7) and specificity of 93% (95% CI87-97%; 98/105). Conclusion This novel HtLAMP-P. vivax assay has the potential to be a useful field applicable molecular diagnostic test for P. vivax infection in elimination settings. PMID:26870958

  15. Local community detection based on modularity metric G

    NASA Astrophysics Data System (ADS)

    Xia, Zhengyou; Gao, Xiangying; Zhang, Xia

    2015-12-01

    In complex network analysis, the local community detection problem is getting more and more attention. Because of the difficulty to get complete information of the network, such as the World Wide Web, the local community detection has been proposed by researcher. That is, we can detect a community from a certain source vertex with limited knowledge of an entire graph. The previous methods of local community detection now are more or less inadequate in some places. In this paper, we have proposed a new local modularity metric G and based on it, a two-phase algorithm is proposed. The method we have taken is a greedy addition algorithm which means adding vertices into the community until G does not increase. Compared with the previous methods, when our method is calculating the modularity metric, the range of vertices what we considered may affect the quality of the community detection wider. The results of experiments show that whether in computer-generated random graph or in the real networks, our method can effectively solve the problem of the local community detection.

  16. Adaptive geostatistical sampling enables efficient identification of malaria hotspots in repeated cross-sectional surveys in rural Malawi

    PubMed Central

    Chipeta, Michael G.; McCann, Robert S.; Phiri, Kamija S.; van Vugt, Michèle; Takken, Willem; Diggle, Peter; Terlouw, Anja D.

    2017-01-01

    Introduction In the context of malaria elimination, interventions will need to target high burden areas to further reduce transmission. Current tools to monitor and report disease burden lack the capacity to continuously detect fine-scale spatial and temporal variations of disease distribution exhibited by malaria. These tools use random sampling techniques that are inefficient for capturing underlying heterogeneity while health facility data in resource-limited settings are inaccurate. Continuous community surveys of malaria burden provide real-time results of local spatio-temporal variation. Adaptive geostatistical design (AGD) improves prediction of outcome of interest compared to current random sampling techniques. We present findings of continuous malaria prevalence surveys using an adaptive sampling design. Methods We conducted repeated cross sectional surveys guided by an adaptive sampling design to monitor the prevalence of malaria parasitaemia and anaemia in children below five years old in the communities living around Majete Wildlife Reserve in Chikwawa district, Southern Malawi. AGD sampling uses previously collected data to sample new locations of high prediction variance or, where prediction exceeds a set threshold. We fitted a geostatistical model to predict malaria prevalence in the area. Findings We conducted five rounds of sampling, and tested 876 children aged 6–59 months from 1377 households over a 12-month period. Malaria prevalence prediction maps showed spatial heterogeneity and presence of hotspots—where predicted malaria prevalence was above 30%; predictors of malaria included age, socio-economic status and ownership of insecticide-treated mosquito nets. Conclusions Continuous malaria prevalence surveys using adaptive sampling increased malaria prevalence prediction accuracy. Results from the surveys were readily available after data collection. The tool can assist local managers to target malaria control interventions in areas with the

  17. Identification and localization of ERD2 in the malaria parasite Plasmodium falciparum: separation from sites of sphingomyelin synthesis and implications for organization of the Golgi.

    PubMed Central

    Elmendorf, H G; Haldar, K

    1993-01-01

    The ERD2 gene product in mammalian cells and yeast is a receptor required for protein retention in the endoplasmic reticulum (ER); immunolocalization studies indicate that the protein is concentrated in the cis Golgi. We have identified a homologue of ERD2 in the malaria parasite, Plasmodium falciparum (PfERD2). The deduced protein sequence is 42% identical to mammalian and yeast homologues and bears striking homology in its proposed tertiary structure. PfERD2 is tightly confined to a single focus of staining in the perinuclear region as seen by indirect immunofluorescence. This is redistributed by brefeldin A (BFA) to a diffuse pattern similar to that of parasite BiP, a marker for the ER; removal of the drug results in recovery of the single focus, consistent with the localization of PfERD2 to the parasite Golgi and its participation in a retrograde transport pathway to the ER. Sphingomyelin synthesis is a second resident activity of the cis Golgi whose organization is sensitive to BFA in mammalian cells. Within the parasite it again localizes to a perinuclear region but does not reorganize upon BFA treatment. The results strongly suggest that these two activities are in distinct compartments of the Golgi in the malaria parasite. Images PMID:8223485

  18. Imported malaria.

    PubMed

    Schultz, M G

    1974-01-01

    There have been 4 waves of imported malaria in the USA. They occurred during the colonization of the country and during the Second World War, the UN Police Action in Korea, and the Viet-Nam conflict. The first 3 episodes are briefly described and the data on imported malaria from Viet-Nam are discussed in detail.Endemic malaria is resurgent in many tropical countries and international travel is also on the rise. This increases the likelihood of malaria being imported from an endemic area and introduced into a receptive area. The best defence for countries threatened by imported malaria is a vigorous surveillance programme. The principles of surveillance are discussed and an example of their application is provided by a description of the methods used to conduct surveillance of malaria in the USA.

  19. Correlation between automatic detection of malaria on thin film and experts' parasitaemia scores

    NASA Astrophysics Data System (ADS)

    Sunarko, Budi; Williams, Simon; Prescott, William R.; Byker, Scott M.; Bottema, Murk J.

    2017-03-01

    An algorithm was developed to diagnose the presence of malaria and to estimate the depth of infection by automatically counting individual normal and infected erythrocytes in images of thin blood smears. During the training stage, the parameters of the algorithm were optimized to maximize correlation with estimates of parasitaemia from expert human observers. The correlation was tested on a set of 1590 images from seven thin film blood smears. The correlation between the results from the algorithm and expert human readers was r = 0.836. Results indicate that reliable estimates of parasitaemia may be achieved by computational image analysis methods applied to images of thin film smears. Meanwhile, compared to biological experiments, the algorithm fitted well the three high parasitaemia slides and a mid-level parasitaemia slide, and overestimated the three low parasitaemia slides. To improve the parasitaemia estimation, the sources of the overestimation were identified. Emphasis is laid on the importance of further research in order to identify parasites independently of their erythrocyte hosts

  20. Effects of Local Anthropogenic Changes on Potential Malaria Vector Anopheles hyrcanus and West Nile Virus Vector Culex modestus, Camargue, France

    PubMed Central

    Ponçon, Nicolas; Balenghien, Thomas; Toty, Céline; Ferré, Jean Baptiste; Thomas, Cyrille; Dervieux, Alain; L’Ambert, Grégory; Schaffner, Francis; Bardin, Olivier

    2007-01-01

    Using historical data, we highlight the consequences of anthropogenic ecosystem modifications on the abundance of mosquitoes implicated as the current most important potential malaria vector, Anopheles hyrcanus, and the most important West Nile virus (WNV) vector, Culex modestus, in the Camargue region, France. From World War II to 1971, populations of these species increased as rice cultivation expanded in the region in a political context that supported agriculture. They then fell, likely because of decreased cultivation and increased pesticide use to control a rice pest. The species increased again after 2000 with the advent of more targeted pest-management strategies, mainly the results of European regulations decisions. An intertwined influence of political context, environmental constraints, technical improvements, and social factors led to changes in mosquito abundance that had potential consequences on malaria and WNV transmission. These findings suggest that anthropogenic changes should not be underestimated in vectorborne disease recrudescence. PMID:18258028

  1. Seasonal genetic partitioning in the neotropical malaria vector, Anopheles darlingi

    PubMed Central

    2014-01-01

    Background Anopheles darlingi is the main malaria mosquito vector in the Amazonia region. In spite of being considered a riverine, forest-dwelling species, this mosquito is becoming more abundant in peri-urban areas, increasing malaria risk. This has been associated with human-driven environmental changes such as deforestation. Methods Microsatellites were used to characterize A. darlingi from seven localities along the Madeira River, Rondônia (Brazil), collected in the early and late periods of the rainy season. Results Two genetically distinct subpopulations were detected: one (subpopulation A) was associated with the late rainfall period and seems to be ecologically closer to the typical forest A. darlingi; the other (subpopulation B) was associated with the early rainfall period and is probably more adapted to drier conditions by exploiting permanent anthropogenic breeding sites. Results suggest also a pattern of asymmetric introgression, with more subpopulation A alleles introgressed into subpopulation B. Both subpopulations (and admixed mosquitoes) presented similar malaria infection rates, highlighting the potential for perennial malaria transmission in the region. Conclusions The co-occurrence of two genetically distinct subpopulations of A. darlingi adapted to different periods of rainfall may promote a more perennial transmission of malaria throughout the year. These findings, in a context of strong environmental impact due to deforestation and dam construction, have serious implications for malaria epidemiology and control in the Amazonian region. PMID:24885508

  2. Local prevalence and transmission of avian malaria in the Alakai Plateau of Kauai, Hawaii, U.S.A.

    PubMed

    Glad, Anouk; Crampton, Lisa H

    2015-12-01

    Avian malaria is among the most important threats to native Hawaiian forest birds. It is caused by the parasite Plasmodium relictum and is transmitted by the introduced mosquito vector Culex quinquefasciatus. Temperature increases and precipitation declines due to climate change over the last decade may be responsible for the observed recent expansion in the range and prevalence of avian malaria on the Alakai Plateau, Kauai Island. To examine the hypothesis that conditions are now favorable for transmission of malaria on the Plateau, mosquitoes were sampled with CO2 and Reiter oviposition traps at three sites (Kawaikoi, Halepa'akai, and Koke'e) on several occasions between October, 2013 and April, 2014. P. relictum infection was assessed by PCR or dissection under a microscope. We also surveyed mosquito larvae along Halepa'akai and Kawaikoi streams. We observed that Cx. quinquefasciatus is well established on the Alakai Plateau, as mosquitoes were caught on all field trips, except in April at Halepa'akai, and larvae were found throughout the year. We observed differences in adult abundance among sites and microhabitats (stream vs ridge lines).

  3. Malaria Research

    MedlinePlus

    ... critical role in development of those next-generation strategies. Read more about malaria prevention, treatment and control Global Cooperation Collaboration involving scientists from diverse disciplines is ...

  4. Accuracy of the health information system on malaria surveillance in Vietnam.

    PubMed

    Erhart, A; Thang, N D; Xa, N X; Thieu, N Q; Hung, L X; Hung, N Q; Nam, N V; Toi, L V; Tung, N M; Bien, T H; Tuy, T Q; Cong, L D; Thuan, L K; Coosemans, M; D'Alessandro, U

    2007-03-01

    The health information system (HIS) is a key component of control programs and its accuracy is necessary for the assessment of disease risks, the formulation of priorities and the evaluation of the cost-effectiveness of different interventions. In order to assess the quality of the HIS in estimating malaria morbidity in Vietnam, we compared data obtained by a 2-year active (ACD) and passive case detection (PCD) study with those routinely collected at the local commune health centres (CHC) at three sites having different malaria epidemiology. The majority of malaria cases (80-95%) detected by ACD were missed by the HIS. Similarly, most malaria cases (50-90%) detected by PCD were also missed by the HIS, and this was proportional to the number of active private practitioners. Reasons for this low sensitivity are low CHC attendance, high attendance at private health facilities, widespread self-medication and attendance at central health facilities. In conclusion, although malaria has sharply decreased in Vietnam over the past 10 years, the current HIS greatly underestimates the malaria burden. Involvement of the private sector and the establishment of sentinel sites might improve the quality of data and the relevance of HIS in malaria control.

  5. Fingerprint spoof detection using wavelet based local binary pattern

    NASA Astrophysics Data System (ADS)

    Kumpituck, Supawan; Li, Dongju; Kunieda, Hiroaki; Isshiki, Tsuyoshi

    2017-02-01

    In this work, a fingerprint spoof detection method using an extended feature, namely Wavelet-based Local Binary Pattern (Wavelet-LBP) is introduced. Conventional wavelet-based methods calculate wavelet energy of sub-band images as the feature for discrimination while we propose to use Local Binary Pattern (LBP) operation to capture the local appearance of the sub-band images instead. The fingerprint image is firstly decomposed by two-dimensional discrete wavelet transform (2D-DWT), and then LBP is applied on the derived wavelet sub-band images. Furthermore, the extracted features are used to train Support Vector Machine (SVM) classifier to create the model for classifying the fingerprint images into genuine and spoof. Experiments that has been done on Fingerprint Liveness Detection Competition (LivDet) datasets show the improvement of the fingerprint spoof detection by using the proposed feature.

  6. Signal detection to identify serious adverse events (neuropsychiatric events) in travelers taking mefloquine for chemoprophylaxis of malaria

    PubMed Central

    Naing, Cho; Aung, Kyan; Ahmed, Syed Imran; Mak, Joon Wah

    2012-01-01

    Background For all medications, there is a trade-off between benefits and potential for harm. It is important for patient safety to detect drug-event combinations and analyze by appropriate statistical methods. Mefloquine is used as chemoprophylaxis for travelers going to regions with known chloroquine-resistant Plasmodium falciparum malaria. As such, there is a concern about serious adverse events associated with mefloquine chemoprophylaxis. The objective of the present study was to assess whether any signal would be detected for the serious adverse events of mefloquine, based on data in clinicoepidemiological studies. Materials and methods We extracted data on adverse events related to mefloquine chemoprophylaxis from the two published datasets. Disproportionality reporting of adverse events such as neuropsychiatric events and other adverse events was presented in the 2 × 2 contingency table. Reporting odds ratio and corresponding 95% confidence interval [CI] data-mining algorithm was applied for the signal detection. The safety signals are considered significant when the ROR estimates and the lower limits of the corresponding 95% CI are ≥2. Results Two datasets addressing adverse events of mefloquine chemoprophylaxis (one from a published article and one from a Cochrane systematic review) were included for analyses. Reporting odds ratio 1.58, 95% CI: 1.49–1.68 based on published data in the selected article, and 1.195, 95% CI: 0.94–1.44 based on data in the selected Cochrane review. Overall, in both datasets, the reporting odds ratio values of lower 95% CI were less than 2. Conclusion Based on available data, findings suggested that signals for serious adverse events pertinent to neuropsychiatric event were not detected for mefloquine. Further studies are needed to substantiate this. PMID:22936859

  7. Vehicle Localization by LIDAR Point Correlation Improved by Change Detection

    NASA Astrophysics Data System (ADS)

    Schlichting, A.; Brenner, C.

    2016-06-01

    LiDAR sensors are proven sensors for accurate vehicle localization. Instead of detecting and matching features in the LiDAR data, we want to use the entire information provided by the scanners. As dynamic objects, like cars, pedestrians or even construction sites could lead to wrong localization results, we use a change detection algorithm to detect these objects in the reference data. If an object occurs in a certain number of measurements at the same position, we mark it and every containing point as static. In the next step, we merge the data of the single measurement epochs to one reference dataset, whereby we only use static points. Further, we also use a classification algorithm to detect trees. For the online localization of the vehicle, we use simulated data of a vertical aligned automotive LiDAR sensor. As we only want to use static objects in this case as well, we use a random forest classifier to detect dynamic scan points online. Since the automotive data is derived from the LiDAR Mobile Mapping System, we are able to use the labelled objects from the reference data generation step to create the training data and further to detect dynamic objects online. The localization then can be done by a point to image correlation method using only static objects. We achieved a localization standard deviation of about 5 cm (position) and 0.06° (heading), and were able to successfully localize the vehicle in about 93 % of the cases along a trajectory of 13 km in Hannover, Germany.

  8. The relationship between species detection probability and local extinction probability

    USGS Publications Warehouse

    Alpizar-Jara, R.; Nichols, J.D.; Hines, J.E.; Sauer, J.R.; Pollock, K.H.; Rosenberry, C.S.

    2004-01-01

    In community-level ecological studies, generally not all species present in sampled areas are detected. Many authors have proposed the use of estimation methods that allow detection probabilities that are < 1 and that are heterogeneous among species. These methods can also be used to estimate community-dynamic parameters such as species local extinction probability and turnover rates (Nichols et al. Ecol Appl 8:1213-1225; Conserv Biol 12:1390-1398). Here, we present an ad hoc approach to estimating community-level vital rates in the presence of joint heterogeneity of detection probabilities and vital rates. The method consists of partitioning the number of species into two groups using the detection frequencies and then estimating vital rates (e.g., local extinction probabilities) for each group. Estimators from each group are combined in a weighted estimator of vital rates that accounts for the effect of heterogeneity. Using data from the North American Breeding Bird Survey, we computed such estimates and tested the hypothesis that detection probabilities and local extinction probabilities were negatively related. Our analyses support the hypothesis that species detection probability covaries negatively with local probability of extinction and turnover rates. A simulation study was conducted to assess the performance of vital parameter estimators as well as other estimators relevant to questions about heterogeneity, such as coefficient of variation of detection probabilities and proportion of species in each group. Both the weighted estimator suggested in this paper and the original unweighted estimator for local extinction probability performed fairly well and provided no basis for preferring one to the other.

  9. The relationship between species detection probability and local extinction probability

    USGS Publications Warehouse

    Alpizar-Jara, R.; Nichols, J.D.; Hines, J.E.; Sauer, J.R.; Pollock, K.H.; Rosenberry, C.S.

    2004-01-01

    In community-level ecological studies, generally not all species present in sampled areas are detected. Many authors have proposed the use of estimation methods that allow detection probabilities that are <1 and that are heterogeneous among species. These methods can also be used to estimate community-dynamic parameters such as species local extinction probability and turnover rates (Nichols et al. Ecol Appl 8:1213-1225; Conserv Biol 12:1390-1398). Here, we present an ad hoc approach to estimating community-level vital rates in the presence of joint heterogeneity of detection probabilities and vital rates. The method consists of partitioning the number of species into two groups using the detection frequencies and then estimating vital rates (e.g., local extinction probabilities) for each group. Estimators from each group are combined in a weighted estimator of vital rates that accounts for the effect of heterogeneity. Using data from the North American Breeding Bird Survey, we computed such estimates and tested the hypothesis that detection probabilities and local extinction probabilities were negatively related. Our analyses support the hypothesis that species detection probability covaries negatively with local probability of extinction and turnover rates. A simulation study was conducted to assess the performance of vital parameter estimators as well as other estimators relevant to questions about heterogeneity, such as coefficient of variation of detection probabilities and proportion of species in each group. Both the weighted estimator suggested in this paper and the original unweighted estimator for local extinction probability performed fairly well and provided no basis for preferring one to the other.

  10. Saliency detection for videos using 3D FFT local spectra

    NASA Astrophysics Data System (ADS)

    Long, Zhiling; AlRegib, Ghassan

    2015-03-01

    Bottom-up spatio-temporal saliency detection identifies perceptually important regions of interest in video sequences. The center-surround model proves to be useful for visual saliency detection. In this work, we explore using 3D FFT local spectra as features for saliency detection within the center-surround framework. We develop a spectral location based decomposition scheme to divide a 3D FFT cube into two components, one related to temporal changes and the other related to spatial changes. Temporal saliency and spatial saliency are detected separately using features derived from each spectral component through a simple center-surround comparison method. The two detection results are then combined to yield a saliency map. We apply the same detection algorithm to different color channels (YIQ) and incorporate the results into the final saliency determination. The proposed technique is tested with the public CRCNS database. Both visual and numerical evaluations verify the promising performance of our technique.

  11. Joint detection and localization of multiple anatomical landmarks through learning

    NASA Astrophysics Data System (ADS)

    Dikmen, Mert; Zhan, Yiqiang; Zhou, Xiang Sean

    2008-03-01

    Reliable landmark detection in medical images provides the essential groundwork for successful automation of various open problems such as localization, segmentation, and registration of anatomical structures. In this paper, we present a learning-based system to jointly detect (is it there?) and localize (where?) multiple anatomical landmarks in medical images. The contributions of this work exist in two aspects. First, this method takes the advantage from the learning scenario that is able to automatically extract the most distinctive features for multi-landmark detection. Therefore, it is easily adaptable to detect arbitrary landmarks in various kinds of imaging modalities, e.g., CT, MRI and PET. Second, the use of multi-class/cascaded classifier architecture in different phases of the detection stage combined with robust features that are highly efficient in terms of computation time enables a seemingly real time performance, with very high localization accuracy. This method is validated on CT scans of different body sections, e.g., whole body scans, chest scans and abdominal scans. Aside from improved robustness (due to the exploitation of spatial correlations), it gains a run time efficiency in landmark detection. It also shows good scalability performance under increasing number of landmarks.

  12. Eradicating malaria.

    PubMed

    Breman, Joel G

    2009-01-01

    The renewed interest in malaria research and control is based on the intolerable toll this disease takes on young children and pregnant women in Africa and other vulnerable populations; 150 to 300 children die each hour from malaria amounting to 1 to 2 million deaths yearly. Malaria-induced neurologic impairment, anemia, hypoglycemia, and low birth weight imperil normal development and survival. Resistance of Plasmodium falciparum to drugs and Anopheles mosquitoes to insecticides has stimulated discovery and development of artemisinin-based combination treatments (ACTs) and other drugs, long-lasting insecticide-treated bednets (with synthetic pyrethroids) and a search for non-toxic, long-lasting, affordable insecticides for indoor residual spraying (IRS). Malaria vaccine development and testing are progressing rapidly and a recombinant protein (RTS,S/AS02A) directed against the circumsporozoite protein is soon to be in Phase 3 trials. Support for malaria control, research, and advocacy through the Global Fund for HIV/AIDS, Tuberculosis and Malaria, the U.S. President's Malaria Initiative, the Bill & Melinda Gates Foundation, WHO and other organizations is resulting in decreasing morbidity and mortality in many malarious countries. Sustainability of effective programs through training and institution strengthening will be the key to malaria elimination coupled with improved surveillance and targeted research.

  13. Linking local knowledge with global action: examining the Global Fund to Fight AIDS, Tuberculosis and Malaria through a knowledge system lens.

    PubMed

    van Kerkhoff, Lorrae; Szlezák, Nicole

    2006-08-01

    New global public health institutions are increasingly emphasizing transparency in decision-making, developing-country ownership of projects and programmes, and merit- and performance-based funding. Such principles imply an institutional response to the challenge of bridging the "know-do gap", by basing decisions explicitly on results, evidence and best practice. Using a knowledge systems framework, we examine how the Global Fund to Fight AIDS, Tuberculosis and Malaria has affected the ways in which knowledge is used in efforts to combat these three diseases. We outline the formal knowledge system embedded in current rules and practices associated with the Global Fund's application process, and give three examples that illustrate the complexity of the knowledge system in action: human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) policy in China; successful applications from Haiti; and responses to changing research on malaria. These examples show that the Global Fund has created strong incentives for knowledge to flow to local implementers, but with little encouragement and few structures for the potentially valuable lessons from implementation to flow back to global best practice or research-based knowledge. The Global Fund could play an influential role in fostering much-needed learning from implementation. We suggest that three initial steps are required to start this process: acknowledging shared responsibility for learning across the knowledge system; analysing the Global Fund's existing data (and refining data collection over time); and supporting recipients and technical partners to invest resources in linking implementation with best practice and research.

  14. Linking local knowledge with global action: examining the Global Fund to Fight AIDS, Tuberculosis and Malaria through a knowledge system lens.

    PubMed Central

    van Kerkhoff, Lorrae; Szlezák, Nicole

    2006-01-01

    New global public health institutions are increasingly emphasizing transparency in decision-making, developing-country ownership of projects and programmes, and merit- and performance-based funding. Such principles imply an institutional response to the challenge of bridging the "know-do gap", by basing decisions explicitly on results, evidence and best practice. Using a knowledge systems framework, we examine how the Global Fund to Fight AIDS, Tuberculosis and Malaria has affected the ways in which knowledge is used in efforts to combat these three diseases. We outline the formal knowledge system embedded in current rules and practices associated with the Global Fund's application process, and give three examples that illustrate the complexity of the knowledge system in action: human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) policy in China; successful applications from Haiti; and responses to changing research on malaria. These examples show that the Global Fund has created strong incentives for knowledge to flow to local implementers, but with little encouragement and few structures for the potentially valuable lessons from implementation to flow back to global best practice or research-based knowledge. The Global Fund could play an influential role in fostering much-needed learning from implementation. We suggest that three initial steps are required to start this process: acknowledging shared responsibility for learning across the knowledge system; analysing the Global Fund's existing data (and refining data collection over time); and supporting recipients and technical partners to invest resources in linking implementation with best practice and research. PMID:16917650

  15. Malaria Parasitemia among Febrile Patients Seeking Clinical Care at an Outpatient Health Facility in an Urban Informal Settlement Area in Nairobi, Kenya

    PubMed Central

    Njuguna, Henry N.; Montgomery, Joel M.; Cosmas, Leonard; Wamola, Newton; Oundo, Joseph O.; Desai, Meghna; Buff, Ann M.; Breiman, Robert F.

    2016-01-01

    Nairobi is considered a low-risk area for malaria transmission, but travel can influence transmission of malaria. We investigated the demographic characteristics and travel history of patients with documented fever and malaria in a study clinic in a population-based surveillance system over a 5-year period, January 1, 2007 to December 31, 2011. During the study period, 11,480 (68%) febrile patients had a microscopy test performed for malaria, of which 2,553 (22%) were positive. Malaria was detected year-round with peaks in January, May, and September. Children aged 5–14 years had the highest proportion (28%) of positive results followed by children aged 1–4 years (23%). Almost two-thirds of patients with malaria reported traveling outside Nairobi; 79% of these traveled to three counties in western Kenya. History of recent travel (i.e., in past month) was associated with malaria parasitemia (odds ratio: 10.0, 95% confidence interval: 9.0–11.0). Malaria parasitemia was frequently observed among febrile patients at a health facility in the urban slum of Kibera, Nairobi. The majority of patients had traveled to western Kenya. However, 34% reported no travel history, which raises the possibility of local malaria transmission in this densely populated, urban setting. These findings have important implications for malaria control in large Nairobi settlements. PMID:26598567

  16. Malaria Parasitemia Among Febrile Patients Seeking Clinical Care at an Outpatient Health Facility in an Urban Informal Settlement Area in Nairobi, Kenya.

    PubMed

    Njuguna, Henry N; Montgomery, Joel M; Cosmas, Leonard; Wamola, Newton; Oundo, Joseph O; Desai, Meghna; Buff, Ann M; Breiman, Robert F

    2016-01-01

    Nairobi is considered a low-risk area for malaria transmission, but travel can influence transmission of malaria. We investigated the demographic characteristics and travel history of patients with documented fever and malaria in a study clinic in a population-based surveillance system over a 5-year period, January 1, 2007 to December 31, 2011. During the study period, 11,480 (68%) febrile patients had a microscopy test performed for malaria, of which 2,553 (22%) were positive. Malaria was detected year-round with peaks in January, May, and September. Children aged 5-14 years had the highest proportion (28%) of positive results followed by children aged 1-4 years (23%). Almost two-thirds of patients with malaria reported traveling outside Nairobi; 79% of these traveled to three counties in western Kenya. History of recent travel (i.e., in past month) was associated with malaria parasitemia (odds ratio: 10.0, 95% confidence interval: 9.0-11.0). Malaria parasitemia was frequently observed among febrile patients at a health facility in the urban slum of Kibera, Nairobi. The majority of patients had traveled to western Kenya. However, 34% reported no travel history, which raises the possibility of local malaria transmission in this densely populated, urban setting. These findings have important implications for malaria control in large Nairobi settlements.

  17. Direction finding antenna system for spark detection and localization

    NASA Astrophysics Data System (ADS)

    Topor, Raluca E.; Bucuci, Stefania C.; Tamas, Razvan D.; Danisor, Alin; Dumitrascu, Ana; Berescu, Serban

    2015-02-01

    This paper proposes a novel UWB antenna system for spark detection and localization by using the amplitude comparison direction finding (DF) method. The proposed design consists of two identical axially crossed "padlock" shaped UWB antennas, with unbalanced feeding. Simulation results show that such radiating systems can be used for assessing the direction of arrival for short pulses.

  18. Glaucoma detection based on local binary patterns in fundus photographs

    NASA Astrophysics Data System (ADS)

    Alsheh Ali, Maya; Hurtut, Thomas; Faucon, Timothée.; Cheriet, Farida

    2014-03-01

    Glaucoma, a group of diseases that lead to optic neuropathy, is one of the most common reasons for blindness worldwide. Glaucoma rarely causes symptoms until the later stages of the disease. Early detection of glaucoma is very important to prevent visual loss since optic nerve damages cannot be reversed. To detect glaucoma, purely data-driven techniques have advantages, especially when the disease characteristics are complex and when precise image-based measurements are difficult to obtain. In this paper, we present our preliminary study for glaucoma detection using an automatic method based on local texture features extracted from fundus photographs. It implements the completed modeling of Local Binary Patterns to capture representative texture features from the whole image. A local region is represented by three operators: its central pixel (LBPC) and its local differences as two complementary components, the sign (which is the classical LBP) and the magnitude (LBPM). An image texture is finally described by both the distribution of LBP and the joint-distribution of LBPM and LBPC. Our images are then classified using a nearest-neighbor method with a leave-one-out validation strategy. On a sample set of 41 fundus images (13 glaucomatous, 28 non-glaucomatous), our method achieves 95:1% success rate with a specificity of 92:3% and a sensitivity of 96:4%. This study proposes a reproducible glaucoma detection process that could be used in a low-priced medical screening, thus avoiding the inter-experts variability issue.

  19. Local Barriers and Solutions to Improve Care-Seeking for Childhood Pneumonia, Diarrhoea and Malaria in Kenya, Nigeria and Niger: A Qualitative Study

    PubMed Central

    Bedford, K. Juliet A.; Sharkey, Alyssa B.

    2014-01-01

    We present qualitative research findings on care-seeking and treatment uptake for pneumonia, diarrhoea and malaria among children under 5 in Kenya, Nigeria and Niger. The study aimed to determine the barriers caregivers face in accessing treatment for these conditions; to identify local solutions that facilitate more timely access to treatment; and to present these findings as a platform from which to develop context-specific strategies to improve care-seeking for childhood illness. Kenya, Nigeria and Niger are three high burden countries with low rates of related treatment coverage, particularly in underserved areas. Data were collected in Homa Bay County in Nyanza Province, Kenya; in Kebbi and Cross River States, Nigeria; and in the Maradi and Tillabéri regions of Niger. Primary caregivers of children under 5 who did not regularly engage with health services or present their child at a health facility during illness episodes were purposively selected for interview. Data underwent rigorous thematic analysis. We organise the identified barriers and related solutions by theme: financial barriers; distance/location of health facilities; socio-cultural barriers and gender dynamics; knowledge and information barriers; and health facility deterrents. The relative importance of each differed by locality. Participant suggested solutions ranged from community-level actions to facility-level and more policy-oriented actions, plus actions to change underlying problems such as social perceptions and practices and gender dynamics. We discuss the feasibility and implications of these suggested solutions. Given the high burden of childhood morbidity and mortality due to pneumonia, diarrhoea and malaria in Kenya, Nigeria and Niger, this study provides important insights relating to demand-side barriers and locally proposed solutions. Significant advancements are possible when communities participate in both problem identification and resolution, and are engaged as important

  20. UK malaria treatment guidelines.

    PubMed

    Lalloo, David G; Shingadia, Delane; Pasvol, Geoffrey; Chiodini, Peter L; Whitty, Christopher J; Beeching, Nicholas J; Hill, David R; Warrell, David A; Bannister, Barbara A

    2007-02-01

    Malaria is the tropical disease most commonly imported into the UK, with 1500-2000 cases reported each year, and 10-20 deaths. Approximately three-quarters of reported malaria cases in the UK are caused by Plasmodium falciparum, which is capable of invading a high proportion of red blood cells and rapidly leading to severe or life-threatening multi-organ disease. Most non-falciparum malaria cases are caused by Plasmodium vivax; a few cases are caused by the other two species of Plasmodium: Plasmodium ovale or Plasmodium malariae. Mixed infections with more than 1 species of parasite can occur; they commonly involve P. falciparum with the attendant risks of severe malaria. Management of malaria depends on awareness of the diagnosis and on performing the correct diagnostic tests: the diagnosis cannot be excluded until 3 blood specimens have been examined by an experienced microscopist. There are no typical clinical features of malaria, even fever is not invariably present. The optimum diagnostic procedure is examination of thick and thin blood films by an expert to detect and speciate the malarial parasites; P. falciparum malaria can be diagnosed almost as accurately using rapid diagnostic tests (RDTs) which detect plasmodial antigens or enzymes, although RDTs for other Plasmodium species are not as reliable. The treatment of choice for non-falciparum malaria is a 3-day course of oral chloroquine, to which only a limited proportion of P. vivax strains have gained resistance. Dormant parasites (hypnozoites) persist in the liver after treatment of P. vivax or P. ovale infection: the only currently effective drug for eradication of hypnozoites is primaquine. This must be avoided or given with caution under expert supervision in patients with glucose-6-phosphate dehydrogenase deficiency (G6PD), in whom it may cause severe haemolysis. Uncomplicated P. falciparum malaria can be treated orally with quinine, atovaquone plus proguanil (Malarone) or co-artemether (Riamet

  1. Improved detection of malaria cases in island settings of Vanuatu and Kenya by PCR that targets the Plasmodium mitochondrial cytochrome c oxidase III (cox3) gene.

    PubMed

    Isozumi, Rie; Fukui, Mayumi; Kaneko, Akira; Chan, Chim W; Kawamoto, Fumihiko; Kimura, Masatsugu

    2015-06-01

    Detection of sub-microscopic parasitemia is crucial for all malaria elimination programs. PCR-based methods have proven to be sensitive, but two rounds of amplification (nested PCR) are often needed to detect the presence of Plasmodium DNA. To simplify the detection process, we designed a nested PCR method whereby only the primary PCR is required for the detection of the four major human Plasmodium species. Primers designed for the detection of the fifth species, Plasmodium knowlesi, were not included in this study due to the absence of appropriate field samples. Compared to the standard 18S rDNA PCR method, our cytochrome c oxidase III (cox3) method detected 10-50% more cases while maintaining high sensitivities (1.00) for all four Plasmodium species in our samples from Vanuatu (n=77) and Kenya (n=76). Improvement in detection efficiency was more substantial for samples with sub-microscopic parasitemia (54%) than those with observable parasitemia (10-16%). Our method will contribute to improved malaria surveillance in low endemicity settings.

  2. Overtaking vehicles detection and localization for driver assistance

    NASA Astrophysics Data System (ADS)

    Lin, Jiun-Yann; Huang, Chung-Lin

    2014-03-01

    This paper proposed an effective overtaking vehicle detection and localization system based on wheel detection. Using the windshield-mounted camera, it can detect the vehicles in rear-view and side-view. It extracts the MB-LBP feature for the cascaded Adaboost classifiers. Differing from traditional approaches, our method can overcome the perspective variation of the wheels in the images. It can detect the wheels of different aspect rations with varying scales. After wheel detection, it can locate the overtaking vehicle by pairing the front/rear wheels. The experiments show that our system can identify and locate the vehicle appearing in side-view as well as in rear-view. The performance of wheel detector is demonstrated with the precision rate as 0.91 and recall rate as 0.96.

  3. Reflection symmetry detection using locally affine invariant edge correspondence.

    PubMed

    Wang, Zhaozhong; Tang, Zesheng; Zhang, Xiao

    2015-04-01

    Reflection symmetry detection receives increasing attentions in recent years. The state-of-the-art algorithms mainly use the matching of intensity-based features (such as the SIFT) within a single image to find symmetry axes. This paper proposes a novel approach by establishing the correspondence of locally affine invariant edge-based features, which are superior to the intensity based in the aspects that it is insensitive to illumination variations, and applicable to textureless objects. The locally affine invariance is achieved by simple linear algebra for efficient and robust computations, making the algorithm suitable for detections under object distortions like perspective projection. Commonly used edge detectors and a voting process are, respectively, used before and after the edge description and matching steps to form a complete reflection detection pipeline. Experiments are performed using synthetic and real-world images with both multiple and single reflection symmetry axis. The test results are compared with existing algorithms to validate the proposed method.

  4. Malaria Treatment (United States)

    MedlinePlus

    ... Malaria Branch clinician. malaria@cdc.gov Malaria Treatment (United States) Recommend on Facebook Tweet Share Compartir Treatment of Malaria: Guidelines For Clinicians (United States) Download PDF version of Parts 1-3 formatted ...

  5. Plasmodium malariae blood-stage dynamics.

    PubMed

    McKenzie, F E; Jeffery, G M; Collins, W E

    2001-06-01

    We examine the dynamics of parasitemia, fever, and gametocytemia reflected in the preintervention charts of 180 malaria-naive U.S. neurosyphilis patients infected with the USPHS strain of Plasmodium malariae, for malariatherapy, focusing on the 84 charts for which more than 35 days of patency preceded intervention and daily records encompassed 92% or more of the duration of each infection. Inoculum size did not influence any outcome variable. Fevers (days with temperatures > or =101 F) followed patterns that fit recognized brood structures more often than did our approximations of merogony cycles (via local peaks in parasitemia), but neither closely fit textbook quartan patterns. There were no discernable patterns in gametocytemia. Successful transmission to mosquitoes increased following subcurative drug treatment but did not depend on detectable gametocytemia.

  6. Malaria Pathogenesis

    NASA Astrophysics Data System (ADS)

    Miller, Louis H.; Good, Michael F.; Milon, Genevieve

    1994-06-01

    Malaria is a disease caused by repeated cycles of growth of the parasite Plasmodium in the erythrocyte. Various cellular and molecular strategies allow the parasite to evade the human immune response for many cycles of parasite multiplication. Under certain circumstances Plasmodium infection causes severe anemia or cerebral malaria; the expression of disease is influenced by both parasite and host factors, as exemplified by the exacerbation of disease during pregnancy. This article provides an overview of malaria pathogenesis, synthesizing the recent field, laboratory, and epidemiological data that will lead to the development of strategies to reduce mortality and morbidity.

  7. First field trial of an immunoradiometric assay for the detection of malaria sporozoites in mosquitoes

    SciTech Connect

    Collins, F.H.; Zavala, F.; Graves, P.M.; Cochrane, A.H.; Gwadz, R.W.; Akoh, J.; Nussenzweig, R.S.

    1984-07-01

    An immunoradiometric assay (IRMA) using a monoclonal antibody to the major surface protein of Plasmodium falciparum sporozoites was used to assess the P. falciparum sporozoite rate in a West African population of Anopheles gambiae (s.1.). Unlike current dissection techniques, the IRMA could detect sporozoite antigen in dried as well as fresh mosquitoes. In a controlled comparison, the sensitivity of the IRMA was comparable that of the dissection technique. Additionally, the IRMA was species specific and quantitative. Sensitivity of the assay was sufficient to detect sporozoite infections resulting from the development of a single oocyst.

  8. Detecting and localizing the foci in human epileptic seizures

    NASA Astrophysics Data System (ADS)

    Ben-Jacob, Eshel; Boccaletti, Stefano; Pomyalov, Anna; Procaccia, Itamar; Towle, Vernon L.

    2007-12-01

    We consider the electrical signals recorded from a subdural array of electrodes placed on the pial surface of the brain for chronic evaluation of epileptic patients before surgical resection. A simple and computationally fast method to analyze the interictal phase synchrony between such electrodes is introduced and developed with the aim of detecting and localizing the foci of the epileptic seizures. We evaluate the method by comparing the results of surgery to the localization predicted here. We find an indication of good correspondence between the success or failure in the surgery and the agreement between our identification and the regions actually operated on.

  9. Lower arm electromyography (EMG) activity detection using local binary patterns.

    PubMed

    McCool, Paul; Chatlani, Navin; Petropoulakis, Lykourgos; Soraghan, John J; Menon, Radhika; Lakany, Heba

    2014-09-01

    This paper presents a new electromyography activity detection technique in which 1-D local binary pattern histograms are used to distinguish between periods of activity and inactivity in myoelectric signals. The algorithm is tested on forearm surface myoelectric signals occurring due to hand gestures. The novel features of the presented method are that: 1) activity detection is performed across multiple channels using few parameters and without the need for majority vote mechanisms, 2) there are no per-channel thresholds to be tuned, which makes the process of activity detection easier and simpler to implement and less prone to errors, 3) it is not necessary to measure the properties of the signal during a quiescent period before using the algorithm. The algorithm is compared to other offline single- and double-threshold activity detection methods and, for the data sets tested, it is shown to have a better overall performance with greater tolerance to the noise in the real data set used.

  10. Disentangling the Effect of Local and Global Spatial Variation on a Mosquito-Borne Infection in a Neotropical Heterogeneous Environment

    PubMed Central

    Grillet, María-Eugenia; Barrera, Roberto; Martínez, Juan-Eudes; Berti, Jesús; Fortin, Marie-Josée

    2010-01-01

    Mosquito-borne pathogen transmission exhibits spatial-temporal variability caused by ecological interactions acting at different scales. We used local spatial statistics and geographically weighted regression (GWR) to determine the spatial pattern of malaria incidence and persistence in northeastern Venezuela. Seven to 11 hot spots of malaria transmission were detected by using local spatial statistics, although disease persistence was explained only for four of those hot spots. The GWR models greatly improved predictions of malaria risk compared with ordinary least squares (OLS) regression models. Malaria incidence was largely explained by the proximity to and number of Anopheles aquasalis habitats nearby (1–3 km), and low-elevation terrains. Disease persistence was associated with greater human population density, lower elevations, and proximity to aquatic habitats. However, there was significant local spatial variation in the relationship between malaria and environmental variables. Spatial modeling improves the understanding of the causal factors operating at several scales in the transmission of malaria. PMID:20133991

  11. Accounting for Limited Detection Efficiency and Localization Precision in Cluster Analysis in Single Molecule Localization Microscopy

    PubMed Central

    Shivanandan, Arun; Unnikrishnan, Jayakrishnan; Radenovic, Aleksandra

    2015-01-01

    Single Molecule Localization Microscopy techniques like PhotoActivated Localization Microscopy, with their sub-diffraction limit spatial resolution, have been popularly used to characterize the spatial organization of membrane proteins, by means of quantitative cluster analysis. However, such quantitative studies remain challenged by the techniques’ inherent sources of errors such as a limited detection efficiency of less than 60%, due to incomplete photo-conversion, and a limited localization precision in the range of 10 – 30nm, varying across the detected molecules, mainly depending on the number of photons collected from each. We provide analytical methods to estimate the effect of these errors in cluster analysis and to correct for them. These methods, based on the Ripley’s L(r) – r or Pair Correlation Function popularly used by the community, can facilitate potentially breakthrough results in quantitative biology by providing a more accurate and precise quantification of protein spatial organization. PMID:25794150

  12. Local graph regularized coding for salient object detection

    NASA Astrophysics Data System (ADS)

    Huo, Lina; Yang, Shuyuan; Jiao, Licheng; Wang, Shuang; Shi, Jiao

    2016-07-01

    Subspace segmentation based salient object detection has received increasing interests in recent years. To preserve the locality and similarity of regions, a grouping effect of representation is introduced to segment the salient object and background in subspace. Then a new saliency map is calculated by incorporating this local graph regularizer into coding, which explicitly explores the data self-representation model and thus locate more accurate salient regions. Moreover, a heuristic object-based dictionary from background superpixels is obtained in border set removing the image regions within the potential object regions. Experimental results on four large benchmark databases demonstrate that the proposed method performs favorably against eight recent state-of-the-art methods in terms of three evaluation criterions, with a reduction of MAE by 19.8% than GR and 29.3% than CB in the two SED datasets, respectively. Meanwhile, our method also runs faster than the comparative detection approaches.

  13. Shooter Localization using Soldier-Worn Gunfire Detection Systems

    DTIC Science & Technology

    2011-07-01

    localization, gunfire detection system, maximum likelihood estimation, Gauss -Newton method. I. INTRODUCTION There is an eminent need for highly accurate...is given in section IV. Section V presents the Gauss -Newton method to solve the nonlinear least-squares problem and section VI presents the results...i Figure 1. Geometry of the bullet trajectory and propagation of the muzzle blast and shockwave to the sensor node. When a gun fires, the blast from

  14. Malaria vaccine.

    PubMed

    1994-05-01

    Some have argued that the vaccine against malaria developed by Manuel Pattaroyo, a Colombian scientist, is being tested prematurely in humans and that it is unlikely to be successful. While the Pattaroyo vaccine has been shown to confer protection against the relatively mild malaria found in Colombia, doubts exist over whether it will be effective in Africa. Encouraging first results, however, are emerging from field tests in Tanzania. The vaccine triggered a strong new immune response, even in individuals previously exposed to malaria. Additional steps must be taken to establish its impact upon mortality and morbidity. Five major trials are underway around the world. The creator estimates that the first ever effective malaria vaccine could be available for widespread use within five years and he has no intention of securing a patent for the discovery. In another development, malaria specialists from 35 African countries convened at an international workshop in Zimbabwe to compare notes. Participants disparaged financial outlays for the fight against malaria equivalent to 2% of total AIDS funding as insufficient; noted intercountry differences in prevention, diagnosis, and treatment; and found information exchange between anglophone and francophone doctors to be generally poor.

  15. WHO Expert Committee on Malaria. Seventeenth report.

    PubMed

    1979-01-01

    This publication consists of guidelines to assist health administrators and planners in planning, implementing, and evaluating malaria control programs that reflect the reorientation of the World Health Organization malaria control strategy endorsed by the World Health Assembly. The report stresses approaches to malaria control, describing the recent resurgence of malaria and present constraints on malaria control; prerequisites for implementation of the revised antimalaria strategy; objectives of a malaria control program; factors affecting planning of control programs including epidemiological factors related to the environment, man, the vector, and the parasite; socioeconomic factors; and the use of antimalaria measures in 4 different situations for reduction and prevention of mortality due to malaria, reduction and prevention of mortality and morbidity particularly in high risk groups, reduction of prevalence and endemicity of malaria, or countrywide malaria control aimed ultimately at eradication; program implementation, including definition of targets, interrelationship of the malaria services, general health services, and community, and program implementation in relation to each of the 4 tactical variants; and general principles, operational and epidemiological criteria, and socioeconomic indicators for program evaluation. Factors determining malaria epidemics, outbreaks of malaria during eradication or control campaigns, forecasting and detection of malaria epidemics, and control of epidemics are then discussed. Training in malaria control and advances in antimalaria measures including drugs, immunological methods, antimosquito measures, and biological and genetic approaches to vector control and their potential value are assessed. Program coordination between countries and at regional and global levels and data collection and dissemination for international surveillance are discussed. A series of recommendations is offered for various aspects of malaria

  16. Utilizing Metalized Fabrics for Liquid and Rip Detection and Localization

    SciTech Connect

    Holland, Stephen; Mahan, Cody; Kuhn, Michael J; Rowe, Nathan C

    2013-01-01

    This paper proposes a novel technique for utilizing conductive textiles as a distributed sensor for detecting and localizing liquids (e.g., blood), rips (e.g., bullet holes), and potentially biosignals. The proposed technique is verified through both simulation and experimental measurements. Circuit theory is utilized to depict conductive fabric as a bounded, near-infinite grid of resistors. Solutions to the well-known infinite resistance grid problem are used to confirm the accuracy and validity of this modeling approach. Simulations allow for discontinuities to be placed within the resistor matrix to illustrate the effects of bullet holes within the fabric. A real-time experimental system was developed that uses a multiplexed Wheatstone bridge approach to reconstruct the resistor grid across the conductive fabric and detect liquids and rips. The resistor grid model is validated through a comparison of simulated and experimental results. Results suggest accuracy proportional to the electrode spacing in determining the presence and location of discontinuities in conductive fabric samples. Future work is focused on refining the experimental system to provide more accuracy in detecting and localizing events as well as developing a complete prototype that can be deployed for field testing. Potential applications include intelligent clothing, flexible, lightweight sensing systems, and combat wound detection.

  17. Dependence of malaria detection and species diagnosis by microscopy on parasite density.

    PubMed

    McKenzie, F Ellis; Sirichaisinthop, Jeeraphat; Miller, R Scott; Gasser, Robert A; Wongsrichanalai, Chansuda

    2003-10-01

    Giemsa-stained blood smears from each of 2,190 patients from Thai government-operated clinics on the Thailand-Myanmar border were independently examined by the on-duty microscopists at the clinics and by 2-3 research microscopists, each blinded to the clinics' and each other's reports. Using a strictly defined protocol, a consensus reference-standard blood smear interpretation for each sample was produced by the research microscopists. This result was compared with the clinic's diagnostic interpretation for the corresponding sample with respect to detection of parasitemia and diagnosis of infecting species. Reference-standard results reported parasitemia in 13.2% of the samples reported negative by the clinic. Reference-standard results were negative in 24.3% of the samples reported parasite-positive by the clinic. For samples in which both the reference-standard result and the clinic result reported parasitemia, species identification differed for 13.7% of the samples. The likelihood of parasite detection and correct diagnosis at the clinic varied in accordance with the reference-standard estimates of parasite density.

  18. DEPENDENCE OF MALARIA DETECTION AND SPECIES DIAGNOSIS BY MICROSCOPY ON PARASITE DENSITY

    PubMed Central

    McKENZIE, F. ELLIS; SIRICHAISINTHOP, JEERAPHAT; MILLER, R. SCOTT; GASSER, ROBERT A.; WONGSRICHANALAI, CHANSUDA

    2008-01-01

    Giemsa-stained blood smears from each of 2,190 patients from Thai government-operated clinics on the Thailand-Myanmar border were independently examined by the on-duty microscopists at the clinics and by 2–3 research microscopists, each blinded to the clinics’ and each other’s reports. Using a strictly defined protocol, a consensus reference-standard blood smear interpretation for each sample was produced by the research microscopists. This result was compared with the clinic’s diagnostic interpretation for the corresponding sample with respect to detection of parasitemia and diagnosis of infecting species. Reference-standard results reported parasitemia in 13.2% of the samples reported negative by the clinic. Reference-standard results were negative in 24.3% of the samples reported parasite-positive by the clinic. For samples in which both the reference-standard result and the clinic result reported parasitemia, species identification differed for 13.7% of the samples. The likelihood of parasite detection and correct diagnosis at the clinic varied in accordance with the reference-standard estimates of parasite density. PMID:14640495

  19. A marked decline in the incidence of malaria in a remote region of Malaita, Solomon Islands, 2008 to 2013

    PubMed Central

    Oloifana-Polosovai, Hellen; Gwala, John; Harrington, Humpress; Massey, Peter D; Ribeyro, Elmer; Flores, Angelica; Speare, Christopher; McBride, Edwin; MacLaren, David

    2014-01-01

    Setting Atoifi Adventist Hospital (AAH), Solomon Islands, the only hospital in the East Kwaio region. Objective To use routine surveillance data to assess the trends in malaria from 2008 to 2013. Design Descriptive study of records from (1) AAH laboratory malaria records; (2) admissions to AAH for malaria; and (3) malaria treatments from outpatient records. Results AAH examined 35 608 blood films and diagnosed malaria in 4443 samples comprised of 2667 Plasmodium falciparum (Pf) and 1776 Plasmodium vivax (Pv). Between 2008 and 2013 the total number of malaria cases detected annually decreased by 86.5%, Pf by 96.7% and Pv by 65.3%. The ratio of Pf to Pv reversed in 2010 from 2.06 in 2008 to 0.19 in 2013. For 2013, Pf showed a seasonal pattern with no cases diagnosed in four months. From 2008 to 2013 admissions in AAH for malaria declined by 90.8%, and malaria mortality fell from 54 per 100 000 to zero. The annual parasite index (API) for 2008 and 2013 was 195 and 24, respectively. Village API has identified a group of villages with higher malaria incidence rates. Conclusion The decline in malaria cases in the AAH catchment area has been spectacular, particularly for Pf. This was supported by three sources of hospital surveillance data (laboratory, admissions and treatment records). The decline was associated with the use of artemisinin-based combined therapy and improved vertical social capital between the AAH and the local communities. Calculating village-specific API has highlighted which villages need to be targeted by the AAH malaria control team. PMID:25320674

  20. Focused Screening and Treatment (FSAT): a PCR-based strategy to detect malaria parasite carriers and contain drug resistant P. falciparum, Pailin, Cambodia.

    PubMed

    Hoyer, Stefan; Nguon, Sokomar; Kim, Saorin; Habib, Najibullah; Khim, Nimol; Sum, Sarorn; Christophel, Eva-Maria; Bjorge, Steven; Thomson, Andrew; Kheng, Sim; Chea, Nguon; Yok, Sovann; Top, Samphornarann; Ros, Seyha; Sophal, Uth; Thompson, Michelle M; Mellor, Steve; Ariey, Frédéric; Witkowski, Benoit; Yeang, Chhiang; Yeung, Shunmay; Duong, Socheat; Newman, Robert D; Menard, Didier

    2012-01-01

    Recent studies have shown that Plasmodium falciparum malaria parasites in Pailin province, along the border between Thailand and Cambodia, have become resistant to artemisinin derivatives. To better define the epidemiology of P. falciparum populations and to assess the risk of the possible spread of these parasites outside Pailin, a new epidemiological tool named "Focused Screening and Treatment" (FSAT), based on active molecular detection of asymptomatic parasite carriers was introduced in 2010. Cross-sectional malariometric surveys using PCR were carried out in 20 out of 109 villages in Pailin province. Individuals detected as P. falciparum carriers were treated with atovaquone-proguanil combination plus a single dose of primaquine if the patient was non-G6PD deficient. Interviews were conducted to elicit history of cross-border travel that might contribute to the spread of artemisinin-resistant parasites. After directly observed treatment, patients were followed up and re-examined on day 7 and day 28. Among 6931 individuals screened, prevalence of P. falciparum carriers was less than 1%, of whom 96% were asymptomatic. Only 1.6% of the individuals had a travel history or plans to go outside Cambodia, with none of those tested being positive for P. falciparum. Retrospective analysis, using 2010 routine surveillance data, showed significant differences in the prevalence of asymptomatic carriers discovered by FSAT between villages classified as "high risk" and "low risk" based on malaria incidence data. All positive individuals treated and followed-up until day 28 were cured. No mutant-type allele related to atovaquone resistance was found. FSAT is a potentially useful tool to detect, treat and track clusters of asymptomatic carriers of P. falciparum along with providing valuable epidemiological information regarding cross-border movements of potential malaria parasite carriers and parasite gene flow.

  1. Focused Screening and Treatment (FSAT): A PCR-Based Strategy to Detect Malaria Parasite Carriers and Contain Drug Resistant P. falciparum, Pailin, Cambodia

    PubMed Central

    Hoyer, Stefan; Nguon, Sokomar; Kim, Saorin; Habib, Najibullah; Khim, Nimol; Sum, Sarorn; Christophel, Eva-Maria; Bjorge, Steven; Thomson, Andrew; Kheng, Sim; Chea, Nguon; Yok, Sovann; Top, Samphornarann; Ros, Seyha; Sophal, Uth; Thompson, Michelle M.; Mellor, Steve; Ariey, Frédéric; Witkowski, Benoit; Yeang, Chhiang; Yeung, Shunmay; Duong, Socheat; Newman, Robert D.; Menard, Didier

    2012-01-01

    Recent studies have shown that Plasmodium falciparum malaria parasites in Pailin province, along the border between Thailand and Cambodia, have become resistant to artemisinin derivatives. To better define the epidemiology of P. falciparum populations and to assess the risk of the possible spread of these parasites outside Pailin, a new epidemiological tool named “Focused Screening and Treatment” (FSAT), based on active molecular detection of asymptomatic parasite carriers was introduced in 2010. Cross-sectional malariometric surveys using PCR were carried out in 20 out of 109 villages in Pailin province. Individuals detected as P. falciparum carriers were treated with atovaquone-proguanil combination plus a single dose of primaquine if the patient was non-G6PD deficient. Interviews were conducted to elicit history of cross-border travel that might contribute to the spread of artemisinin-resistant parasites. After directly observed treatment, patients were followed up and re-examined on day 7 and day 28. Among 6931 individuals screened, prevalence of P. falciparum carriers was less than 1%, of whom 96% were asymptomatic. Only 1.6% of the individuals had a travel history or plans to go outside Cambodia, with none of those tested being positive for P. falciparum. Retrospective analysis, using 2010 routine surveillance data, showed significant differences in the prevalence of asymptomatic carriers discovered by FSAT between villages classified as “high risk” and “low risk” based on malaria incidence data. All positive individuals treated and followed-up until day 28 were cured. No mutant-type allele related to atovaquone resistance was found. FSAT is a potentially useful tool to detect, treat and track clusters of asymptomatic carriers of P. falciparum along with providing valuable epidemiological information regarding cross-border movements of potential malaria parasite carriers and parasite gene flow. PMID:23049687

  2. [Diagnosis of malaria in Antananarivo City: examination of the results obtained at the Institut Pasteur de Madagascar from 2001 to 2004].

    PubMed

    Bencimon, C; Belmonte, O; Randrianarivelojosia, M; Grosjean, P; Pfister, P; Combe, P

    2006-07-01

    Malaria diagnosis is part of the daily activities of the Clinical Biology Center (CBC) of the Institut Pasteur de Madagascar in Antananarivo. Over a period of four years (2001-2004), regardless the methods being used, out of 6537 blood samples examined, 159 (2.43%) tests were positive. All four species of Plasmodium infecting human. were detected with a high prevalence of P. falciparum (87.2%). 49/159 patients were foreigners, but their files did not allow us to distinguish imported from locally acquired malaria cases. Also, among Malagasy patients, there was no possibility to recognize introduced malaria cases (contracted in coastal areas). In Madagascar malaria remains a public health problem. But fever and recent history of fever are often considered and treated as malaria. Our results demonstrated that confirmed malaria rate was very low. Reporting malaria on the basis of clinical signs overestimates malaria cases at the national level. The importance of malaria biological diagnosis is discussed in this article.

  3. Passive detection, characterization, and localization of multiple LFMCW LPI signals

    NASA Astrophysics Data System (ADS)

    Hamschin, Brandon; Clancy, John; Grabbe, Mike; Fortier, Matthew; Novak, John

    2014-06-01

    A method for passive Detection, Characterization, and Localization (DCL) of multiple low power, Linear Frequency Modulated Continuous Wave (LFMCW) (i.e., Low Probability of Intercept (LPI)) signals is proposed. In contrast to other detection and characterization approaches, such as those based on the Wigner-Ville Transform (WVT) 1or the Wigner-Ville Hough Transform (WVHT) ,2 our approach does not begin with a parametric model of the received signal that is specified directly in terms of its LFMCW constituents. Rather, we analyze the signal over time intervals that are short, non-overlapping, and contiguous by modeling it within these intervals as a sum of sinusoidal (i.e., harmonic) components with unknown frequencies, deterministic but unknown amplitudes, unknown order (i.e., number of harmonic components), and unknown noise autocorrelation function. Using this model of the signal, which we refer to as the Short-Time Harmonic Model (STHM), we implement a detection statistic based on Thompson's Method for harmonic analysis,3 which leads to a detection threshold that is a function of False Alarm Probability PFA and not a function of the noise properties. By doing so we reliably detect the presence of multiple LFMCW signals in colored noise without the need for prewhitening, efficiently estimate (i.e., characterize) their parameters, provide estimation error variances for a subset of these parameters, and produce Time-of-Arrival (TOA) estimates that can be used to estimate the geographical location of (i.e., localize) each LFMCW source. Finally, by using the entire time-series we refine these parameter estimates by using them as initial conditions to the Maximum Likelihood Estimator (MLE), which was originally given in1 and later found in2 to be too computationally expensive for multiple LFMCW signals if accurate initial conditions were not available to limit the search space. We demonstrate the performance of our approach via simulation.

  4. Detection of Plasmodium falciparum and Plasmodium vivax subclinical infection in non-endemic region: implications for blood transfusion and malaria epidemiology

    PubMed Central

    2014-01-01

    Background In Brazil, malaria is endemic in the Amazon River basin and non-endemic in the extra-Amazon region, which includes areas of São Paulo state. In this state, a number of autochthonous cases of malaria occur annually, and the prevalence of subclinical infection is unknown. Asymptomatic infections may remain undetected, maintaining transmission of the pathogen, including by blood transfusion. In these report it has been described subclinical Plasmodium infection in blood donors from a blood transfusion centre in São Paulo, Brazil. Methods In this cross-sectional study, representative samples of blood were obtained from 1,108 healthy blood donors at the Fundação Pró-Sangue Hemocentro de São Paulo, the main blood transfusion centre in São Paulo. Malaria exposure was defined by the home region (exposed: forest region; non-exposed: non-forest region). Real-time PCR was used to detect Plasmodium falciparum and Plasmodium vivax. Subclinical malaria cases were geo-referenced. Results Eighty-four (7.41%) blood donors tested positive for Plasmodium; 57 of these were infected by P. falciparum, 25 by P. vivax, and 2 by both. The prevalence of P. falciparum and P. vivax was 5.14 and 2.26, respectively. The overall prevalence ratio (PR) was 3.23 (95% confidence interval (CI) 2.03, 5.13); P. falciparum PR was 16.11 (95% CI 5.87, 44.21) and P. vivax PR was 0.47 (95% CI 0.2, 1.12). Plasmodium falciparum subclinical malaria infection in the Atlantic Forest domain was present in the mountain regions while P. vivax infection was observed in cities from forest-surrounded areas. Conclusions The presence of Plasmodium in healthy blood donors from a region known as non-endemic, which is important in the context of transfusion biosafety, was described. Infected recipients may become asymptomatic carriers and a reservoir for parasites, maintaining their transmission. Furthermore, P. falciparum PR was positively associated with the forest environment, and P. vivax was

  5. Utilizing metalized fabrics for liquid and rip detection and localization

    NASA Astrophysics Data System (ADS)

    Holland, Stephen A.; Mahan, Cody A.; Kuhn, Michael J.; Rowe, Nathan C.

    2013-05-01

    This paper proposes a novel technique for utilizing electrically conductive textiles as a distributed sensor for detecting and localizing liquids (e.g., blood), damage (e.g., rips, cuts, bullet holes) and, potentially, biosignals. The proposed technique is verified through both simulation and experimental measurements. Circuit theory is employed to depict conductive fabric as a bounded, near-infinite grid of resistors. Solutions to the well-known infinite resistance grid problem are used to confirm the accuracy and validity of this modeling approach. Simulations allow for discontinuities to be placed within the resistor matrix to illustrate the effects of bullet holes within the fabric. A real-time experimental system was developed that uses a multiplexed, Wheatstone bridge measurement approach to determine the resistances of a coarse electrode grid across the conductive fabric. Non-uniform resistance values of the grid infer the presence of liquids and rips in the fabric. The resistor-grid model is validated through a comparison of simulated and experimental results. Results suggest accuracy proportional to the electrode spacing in determining the presence and location of disturbances in conductive fabric samples. Future work is focused on refining the experimental system to provide more accuracy in detecting and localizing events (although just the knowledge of a penetration may be adequate for some intended applications) as well as developing a complete prototype that can be deployed for field testing. Potential applications include intelligent clothing, flexible, lightweight sensing systems, and combat wound detection.

  6. Label propagation algorithm based on local cycles for community detection

    NASA Astrophysics Data System (ADS)

    Zhang, Xian-Kun; Fei, Song; Song, Chen; Tian, Xue; Ao, Yang-Yue

    2015-12-01

    Label propagation algorithm (LPA) has been proven to be an extremely fast method for community detection in large complex networks. But an important issue of the algorithm has not yet been properly addressed that random update orders in label propagation process hamper the algorithm robustness of algorithm. We note that when there are multiple maximal labels among a node neighbors' labels, choosing a node' label from which there is a local cycle to the node instead of a random node' label can avoid the labels propagating among communities at random. In this paper, an improved LPA based on local cycles is given. We have evaluated the proposed algorithm on computer-generated networks with planted partition and some real-world networks whose community structure are already known. The result shows that the performance of the proposed approach is even significantly improved.

  7. Network detection of radiation sources using ROSD localization

    SciTech Connect

    Wu, Qishi; Berry, M. L..; Grieme, M.; Rao, Nageswara S; Sen, Satyabrata; Brooks, Richard R

    2015-01-01

    We propose a localization-based radiation source detection (RSD) algorithm using the Ratio of Squared Distance (ROSD) method. Compared with the triangulation-based method, the advantages of this ROSD method are multi-fold: i) source location estimates based on four detectors improve their accuracy, ii) ROSD provides closed-form source location estimates and thus eliminates the imaginary-roots issue, and iii) ROSD produces a unique source location estimate as opposed to two real roots (if any) in triangulation, and obviates the need to identify real phantom roots during clustering.

  8. Characterizing Types of Human Mobility to Inform Differential and Targeted Malaria Elimination Strategies in Northeast Cambodia

    PubMed Central

    Peeters Grietens, Koen; Gryseels, Charlotte; Dierickx, Susan; Bannister-Tyrrell, Melanie; Trienekens, Suzan; Uk, Sambunny; Phoeuk, Pisen; Suon, Sokha; Set, Srun; Gerrets, René; Hoibak, Sarah; Muela Ribera, Joan; Hausmann-Muela, Susanna; Tho, Sochantha; Durnez, Lies; Sluydts, Vincent; d’Alessandro, Umberto; Coosemans, Marc; Erhart, Annette

    2015-01-01

    Human population movements currently challenge malaria elimination in low transmission foci in the Greater Mekong Subregion. Using a mixed-methods design, combining ethnography (n = 410 interviews), malariometric data (n = 4996) and population surveys (n = 824 indigenous populations; n = 704 Khmer migrants) malaria vulnerability among different types of mobile populations was researched in the remote province of Ratanakiri, Cambodia. Different structural types of human mobility were identified, showing differential risk and vulnerability. Among local indigenous populations, access to malaria testing and treatment through the VMW-system and LLIN coverage was high but control strategies failed to account for forest farmers’ prolonged stays at forest farms/fields (61% during rainy season), increasing their exposure (p = 0.002). The Khmer migrants, with low acquired immunity, active on plantations and mines, represented a fundamentally different group not reached by LLIN-distribution campaigns since they were largely unregistered (79%) and unaware of the local VMW-system (95%) due to poor social integration. Khmer migrants therefore require control strategies including active detection, registration and immediate access to malaria prevention and control tools from which they are currently excluded. In conclusion, different types of mobility require different malaria elimination strategies. Targeting mobility without an in-depth understanding of malaria risk in each group challenges further progress towards elimination. PMID:26593245

  9. Detecting Abrupt Changes in a Piecewise Locally Stationary Time Series

    PubMed Central

    Last, Michael; Shumway, Robert

    2007-01-01

    Non-stationary time series arise in many settings, such as seismology, speech-processing, and finance. In many of these settings we are interested in points where a model of local stationarity is violated. We consider the problem of how to detect these change-points, which we identify by finding sharp changes in the time-varying power spectrum. Several different methods are considered, and we find that the symmetrized Kullback-Leibler information discrimination performs best in simulation studies. We derive asymptotic normality of our test statistic, and consistency of estimated change-point locations. We then demonstrate the technique on the problem of detecting arrival phases in earthquakes. PMID:19190715

  10. Copy-move forgery detection using multiresolution local binary patterns.

    PubMed

    Davarzani, Reza; Yaghmaie, Khashayar; Mozaffari, Saeed; Tapak, Meysam

    2013-09-10

    Copy-move forgery is one of the most popular tampering artifacts in digital images. In this paper, we present an efficient method for copy-move forgery detection using Multiresolution Local Binary Patterns (MLBP). The proposed method is robust to geometric distortions and illumination variations of duplicated regions. Furthermore, the proposed block-based method recovers parameters of the geometric transformations. First, the image is divided into overlapping blocks and feature vectors for each block are extracted using LBP operators. The feature vectors are sorted based on lexicographical order. Duplicated image blocks are determined in the block matching step using k-d tree for more time reduction. Finally, in order to both determine the parameters of geometric transformations and remove the possible false matches, RANSAC (RANdom SAmple Consensus) algorithm is used. Experimental results show that the proposed approach is able to precisely detect duplicated regions even after distortions such as rotation, scaling, JPEG compression, blurring and noise adding.

  11. Stability and Wash Resistance of Local Made Mosquito Bednets and Detergents Treated with Pyrethroids against Susceptible Strain of Malaria Vector Anopheles stephensi

    PubMed Central

    Vatandoost, H; Ramin, E; Rassi, Y; Abai, MR

    2009-01-01

    Background We aimed to evaluate different fibres of bednets impregnated with various pyrethroids. The stability of insecticide on the bednet was measured using different methods of washings as well as local made detergents. Methods: The entire test was carried out according to the WHO-recommended methods. In addition, the impact of the numbers of washes on the stability of the insecticides was determined. Permethrin 10% (EC), deltamethrin 10% (SC), lambdacyhalothrin 2.5% (CS) and cyfluthrin 5% (EW) were used at the recommended dosages. Three different local detergents were used. Two kinds of washing methods (shaking, no shaking) were used and in each method four kinds of washings, i.e. no wash, one wash, two washes and three washes was done. The main malaria vectors, Anopheles stephensi, which is susceptible to all insecticides (BEECH strain), was tested with impregnated bednets in 3 minutes exposure time and the mortality was measured after 24 hours recovery period. Knock-down was measured as well using appropriate statistical methods. Results: Lambdacyhalothrin has saved its insecticidal impact after being washed, whereas, deltamethrin has lost its activity faster than other insecticides. Tow other insecticides had moderate effect. Golnar soap detergent has least effect on the durability of insecticides, but the Shoma had the most. Whit increasing the times of washing, insecticidal effects was decreased, but shaking had no influence on the decreasing of the quality of insecticidal impact. Conclusion: Results will be useful for local people who wish to use pyrethroid-impregnated bednets with their own local made detergent and bednets. PMID:22808368

  12. Symmetrized local co-registration optimization for anomalous change detection

    SciTech Connect

    Wohlberg, Brendt E; Theiler, James P

    2009-01-01

    The goal of anomalous change detection (ACD) is to identify what unusual changes have occurred in a scene, based on two images of the scene taken at different times and under different conditions. The actual anomalous changes need to be distinguished from the incidental differences that occur throughout the imagery, and one of the most common and confounding of these incidental differences is due to the misregistration of the images, due to limitations of the registration pre-processing applied to the image pair. We propose a general method to compensate for residual misregistration in any ACD algorithm which constructs an estimate of the degree of 'anomalousness' for every pixel in the image pair. The method computes a modified misregistration-insensitive anomalousness by making local re-registration adjustments to minimize the local anomalousness. In this paper we describe a symmetrized version of our initial algorithm, and find significant performance improvements in the anomalous change detection ROC curves for a number of real and synthetic data sets.

  13. Prostate cancer: multiparametric MR imaging for detection, localization, and staging.

    PubMed

    Hoeks, Caroline M A; Barentsz, Jelle O; Hambrock, Thomas; Yakar, Derya; Somford, Diederik M; Heijmink, Stijn W T P J; Scheenen, Tom W J; Vos, Pieter C; Huisman, Henkjan; van Oort, Inge M; Witjes, J Alfred; Heerschap, Arend; Fütterer, Jurgen J

    2011-10-01

    This review presents the current state of the art regarding multiparametric magnetic resonance (MR) imaging of prostate cancer. Technical requirements and clinical indications for the use of multiparametric MR imaging in detection, localization, characterization, staging, biopsy guidance, and active surveillance of prostate cancer are discussed. Although reported accuracies of the separate and combined multiparametric MR imaging techniques vary for diverse clinical prostate cancer indications, multiparametric MR imaging of the prostate has shown promising results and may be of additional value in prostate cancer localization and local staging. Consensus on which technical approaches (field strengths, sequences, use of an endorectal coil) and combination of multiparametric MR imaging techniques should be used for specific clinical indications remains a challenge. Because guidelines are currently lacking, suggestions for a general minimal protocol for multiparametric MR imaging of the prostate based on the literature and the authors' experience are presented. Computer programs that allow evaluation of the various components of a multiparametric MR imaging examination in one view should be developed. In this way, an integrated interpretation of anatomic and functional MR imaging techniques in a multiparametric MR imaging examination is possible. Education and experience of specialist radiologists are essential for correct interpretation of multiparametric prostate MR imaging findings. Supportive techniques, such as computer-aided diagnosis are needed to obtain a fast, cost-effective, easy, and more reproducible prostate cancer diagnosis out of more and more complex multiparametric MR imaging data.

  14. Nanoscale Membrane Curvature detected by Polarized Localization Microscopy

    NASA Astrophysics Data System (ADS)

    Kelly, Christopher; Maarouf, Abir; Woodward, Xinxin

    Nanoscale membrane curvature is a necessary component of countless cellular processes. Here we present Polarized Localization Microscopy (PLM), a super-resolution optical imaging technique that enables the detection of nanoscale membrane curvature with order-of-magnitude improvements over comparable optical techniques. PLM combines the advantages of polarized total internal reflection fluorescence microscopy and fluorescence localization microscopy to reveal single-fluorophore locations and orientations without reducing localization precision by point spread function manipulation. PLM resolved nanoscale membrane curvature of a supported lipid bilayer draped over polystyrene nanoparticles on a glass coverslip, thus creating a model membrane with coexisting flat and curved regions and membrane radii of curvature as small as 20 nm. Further, PLM provides single-molecule trajectories and the aggregation of curvature-inducing proteins with super-resolution to reveal the correlated effects of membrane curvature, dynamics, and molecular sorting. For example, cholera toxin subunit B has been observed to induce nanoscale membrane budding and concentrate at the bud neck. PLM reveals a previously hidden and critical information of membrane topology.

  15. Acoustic Emission Beamforming for Detection and Localization of Damage

    NASA Astrophysics Data System (ADS)

    Rivey, Joshua Callen

    The aerospace industry is a constantly evolving field with corporate manufacturers continually utilizing innovative processes and materials. These materials include advanced metallics and composite systems. The exploration and implementation of new materials and structures has prompted the development of numerous structural health monitoring and nondestructive evaluation techniques for quality assurance purposes and pre- and in-service damage detection. Exploitation of acoustic emission sensors coupled with a beamforming technique provides the potential for creating an effective non-contact and non-invasive monitoring capability for assessing structural integrity. This investigation used an acoustic emission detection device that employs helical arrays of MEMS-based microphones around a high-definition optical camera to provide real-time non-contact monitoring of inspection specimens during testing. The study assessed the feasibility of the sound camera for use in structural health monitoring of composite specimens during tensile testing for detecting onset of damage in addition to nondestructive evaluation of aluminum inspection plates for visualizing stress wave propagation in structures. During composite material monitoring, the sound camera was able to accurately identify the onset and location of damage resulting from large amplitude acoustic feedback mechanisms such as fiber breakage. Damage resulting from smaller acoustic feedback events such as matrix failure was detected but not localized to the degree of accuracy of larger feedback events. Findings suggest that beamforming technology can provide effective non-contact and non-invasive inspection of composite materials, characterizing the onset and the location of damage in an efficient manner. With regards to the nondestructive evaluation of metallic plates, this remote sensing system allows us to record wave propagation events in situ via a single-shot measurement. This is a significant improvement over

  16. [Current malaria situation in the Republic of Kazakhstan].

    PubMed

    Bismil'din, F B; Shapieva, Zh Zh; Anpilova, E N

    2001-01-01

    The Republic of Kazakhstan is situated in the northern hemisphere on the boundary of two continents--Europe and Asia--at a longitude of 45 degrees E--87 degrees E and a latitude of 40 degrees N--55 degrees N. The total area of the republic is 2,724,900 square kilometers. Kazakhstan shares a border with the Russian Federation to the north-west, north and east: the border between the two countries is almost 6500 km long. To the south, Kazakhstan shares a border with the Central Asian states of Turkmenistan (380 km), Uzbekistan (2300 km) and Kyrgystan (980 km). To the south-east, it shares a border with China (1460 km): to the west is the Caspian Sea (600 km). Thus, the total length of Kazakhstan's external borders is 12,000 km. Because of the geographical, natural and climatic features prevailing throughout most of the Republic, there is a potential danger that local transmission of malaria may begin again if the disease is imported from abroad. The areas most at risk are the Panfilov and Uigur raions of Almaty oblast, which share a border with malaria-endemic regions of China, and the Saryagash and Makhtaral' raions of South Kazakhstan oblast along the border with Uzbekistan. The Government of the Republic of Kazakhstan places particular emphasis on malaria prevention and control, taking into account the historical data about the prevalence of malaria from the late 1920s to the early 1940s, amounting to hundreds of thousands of cases every year. Government Decree No. 840 entitled "Urgent Measures to Protect the Population from Blood-Sucking Insects and Ticks Dangerous to Humans", which lays down measures for the control of malarial mosquitoes in the areas most susceptible to malaria resurgence, was adopted in 1996. The Ministry of Health of the Republic of Kazakhstan issued instructions in 1998 and 1999 which were designed to motivate all health facilities in the field of malaria prevention and control. At present, as part of the directives developed by the

  17. The Properties of IRAS Detected Mergers in the Local Universe

    NASA Astrophysics Data System (ADS)

    Carpineti, Alfredo; Kaviraj, S.; Clements, D. L.; Darg, D.; Hyde, A. K.; Lintott, C.

    2012-01-01

    Galaxy merging is a fundamental aspect of the standard hierarchical galaxy formation paradigm. We have used a large, homogeneous set of nearby mergers, selected through direct visual inspection of the entire SDSS using the GalaxyZoo project, to perform the first blind far-infrared (FIR) study of the local merger population. 3300+ mergers were cross-matched with the Imperial IRAS-FSC Redshift Catalogue, resulting in 606 FIR detections. The IRAS- detected mergers are typically more massive, with smaller separations, weaker tidal forces and bluer colours than their undetected counterparts. The IRAS-detected mergers are mostly (98%) spiral-spiral systems, with a median FIR luminosity of 1011 LSun and a median star-formation rate of around 15 MSun per year. They reside in low density environments but we find no dependence between group richness and their infrared properties. Their SFR seems to depend on the total mass of the system with little dependence on the mass ratio. Optical emission line ratios indicate that the AGN fraction increases with increasing FIR luminosity with a dramatic increase in the members that are ULIRGs . Comparing the typical separations of mergers that are LIRGs and those that are ULIRGs we estimate the timescale for this transition and find a value of (50 ± 16) Myr .

  18. Cerebral Malaria.

    PubMed

    Marsden, P D; Bruce-Chwatt, L J

    1975-01-01

    Cerebral malaria is an acute diffuse encephalopathy associated only with Plasmodium falciparum. It is probably a consequence of the rapid proliferation of the parasites in the body of man in relation to red cell invasion, and results in stagnation of blood flow in cerebralcapillaries with thromobotic occlusion of large numbers of cerebral capillaries. The subsequent cerebral pathology is cerebral infarction with haemorrhage and cerebral oedema. The wide prevalence of P. falciparum in highly endemic areas results in daily challenges to patients from several infected mosquitoes. It is thus important to understand the characteristics of P. falciparum, since this is one of the most important protozoan parasites of man and severe infection from it constitutes one of the few real clinical emergencies in tropical medicine. One of the more important aspects of the practice of medicine in the tropics is to establish a good understanding of the pattern of medical practice in that area. This applies to malaria as well as to other diseases. The neophyte might be somewhat surprised to learn, for example that an experienced colleague who lives in a holoendemic malarious area such as West Africa, sees no cerebral malaria. But the explanation is simple when the doctor concerned has a practice which involves treating adults only. Cerebral malaria is rare in adults, because in highly endemic areas, by the age of 1 year most of the infants in a group under study have already experienced their first falciparum infection. By the time they reach adult life, they have a solid immunity against severe falciparum infections. In fact, "clinical malaria" could occur in such a group under only two circumstances: 1) in pregnancy, a patent infection with P. falciparum might develop, probably due to an IgG drain across the placenta to the foetus;2) in an individual who has constantly taken antimalarials and who may have an immunity at such a low level that when antimalarial therapy is interrupted

  19. Current therapies and prophylaxis of malaria.

    PubMed

    Ehrich, R

    1994-09-01

    Malaria is a potentially life-threatening disease. Although not commonplace in the United States, malaria cases are occurring more frequently due to an influx of military personnel returning from duty in malarious areas, increased numbers of immigrants, and tourist and business travel to endemic areas. Careful history taking and proper laboratory diagnosis are essential in detecting malaria. Malaria should be considered in the differential diagnosis with any fever of unknown origin. Due to the increase in chloroquine resistant P. falciparum malaria worldwide it behooves the clinician to keep abreast of current therapies in the treatment and prophylaxis of malaria. The Centers for Disease Control and Prevention is one of the best resources for up-to-date recommended therapies.

  20. Detection and Localization of Subsurface Two-Dimensional Metallic Objects

    NASA Astrophysics Data System (ADS)

    Meschino, S.; Pajewski, L.; Schettini, G.

    2009-04-01

    "Roma Tre" University, Applied Electronics Dept.v. Vasca Navale 84, 00146 Rome, Italy Non-invasive identification of buried objects in the near-field of a receiver array is a subject of great interest, due to its application to the remote sensing of the earth's subsurface, to the detection of landmines, pipes, conduits, to the archaeological site characterization, and more. In this work, we present a Sub-Array Processing (SAP) approach for the detection and localization of subsurface perfectly-conducting circular cylinders. We consider a plane wave illuminating the region of interest, which is assumed to be a homogeneous, unlossy medium of unknown permittivity containing one or more targets. In a first step, we partition the receiver array so that the field scattered from the targets result to be locally plane at each sub-array. Then, we apply a Direction of Arrival (DOA) technique to obtain a set of angles for each locally plane wave, and triangulate these directions obtaining a collection of crossing crowding in the expected object locations [1]. We compare several DOA algorithms such as the traditional Bartlett and Capon Beamforming, the Pisarenko Harmonic Decomposition (PHD), the Minimum-Norm method, the Multiple Signal Classification (MUSIC) and the Estimation of Signal Parameters via Rotational Techinque (ESPRIT) [2]. In a second stage, we develop a statistical Poisson based model to manage the crossing pattern in order to extract the probable target's centre position. In particular, if the crossings are Poisson distributed, it is possible to feature two different distribution parameters [3]. These two parameters perform two density rate for the crossings, so that we can previously divide the crossing pattern in a certain number of equal-size windows and we can collect the windows of the crossing pattern with low rate parameters (that probably are background windows) and remove them. In this way we can consider only the high rate parameter windows (that most

  1. Binaural Sound Localizer for Azimuthal Movement Detection Based on Diffraction

    PubMed Central

    Kim, Keonwook; Choi, Anthony

    2012-01-01

    Sound localization can be realized by utilizing the physics of acoustics in various methods. This paper investigates a novel detection architecture for the azimuthal movement of sound source based on the interaural level difference (ILD) between two receivers. One of the microphones in the system is surrounded by barriers of various heights in order to cast the direction dependent diffraction of the incoming signal. The gradient analysis of the ILD between the structured and unstructured microphone demonstrates the rotation directions as clockwise, counter clockwise, and no rotation of the sound source. Acoustic experiments with different types of sound source over a wide range of target movements show that the average true positive and false positive rates are 67% and 16%, respectively. Spectral analysis demonstrates that the low frequency delivers decreased true and false positive rates and the high frequency presents increases of both rates, overall. PMID:23112617

  2. Nonlinear damage detection and localization using a time domain approach

    NASA Astrophysics Data System (ADS)

    Boccardi, S.; Calla, D.-B.; Malfense Fierro, G.-P.; Ciampa, F.; Meo, M.

    2016-04-01

    This paper presents a damage detection and localization technique based on nonlinear elastic waves propagation in a damage composite laminate. The proposed method relies on the time of arrival estimation of the second harmonic nonlinear response obtained with second order phase symmetry analysis filtering and burst excitation. The Akaike Information Criterion approach was used to estimate the arrival times measured by six receiver transducers. Then, a combination of Newton's method and unconstrained optimization was employed to solve a system of nonlinear equations in order to obtain the material damage coordinates. To validate this methodology, experimental tests were carried out on a damaged composite plate. The results showed that the technique allows calculating the damage position with high accuracy (maximum error ~5 mm).

  3. Developmental differences in auditory detection and localization of approaching vehicles.

    PubMed

    Barton, Benjamin K; Lew, Roger; Kovesdi, Casey; Cottrell, Nicholas D; Ulrich, Thomas

    2013-04-01

    Pedestrian safety is a significant problem in the United States, with thousands being injured each year. Multiple risk factors exist, but one poorly understood factor is pedestrians' ability to attend to vehicles using auditory cues. Auditory information in the pedestrian setting is increasing in importance with the growing number of quieter hybrid and all-electric vehicles on America's roadways that do not emit sound cues pedestrians expect from an approaching vehicle. Our study explored developmental differences in pedestrians' detection and localization of approaching vehicles. Fifty children ages 6-9 years, and 35 adults participated. Participants' performance varied significantly by age, and with increasing speed and direction of the vehicle's approach. Results underscore the importance of understanding children's and adults' use of auditory cues for pedestrian safety and highlight the need for further research.

  4. Laser-induced fluorescence spectroscopy in tissue local necrosis detection

    NASA Astrophysics Data System (ADS)

    Cip, Ondrej; Buchta, Zdenek; Lesundak, Adam; Randula, Antonin; Mikel, Bretislav; Lazar, Josef; Veverkova, Lenka

    2014-03-01

    The recent effort leads to reliable imaging techniques which can help to a surgeon during operations. The fluorescence spectroscopy was selected as very useful online in vivo imaging method to organics and biological materials analysis. The presented work scopes to a laser induced fluorescence spectroscopy technique to detect tissue local necrosis in small intestine surgery. In first experiments, we tested tissue auto-fluorescence technique but a signal-to-noise ratio didn't express significant results. Then we applied a contrast dye - IndoCyanine Green (ICG) which absorbs and emits wavelengths in the near IR. We arranged the pilot experimental setup based on highly coherent extended cavity diode laser (ECDL) used for stimulating of some critical areas of the small intestine tissue with injected ICG dye. We demonstrated the distribution of the ICG exciter with the first file of shots of small intestine tissue of a rabbit that was captured by high sensitivity fluorescent cam.

  5. Malaria and Travelers

    MedlinePlus

    ... CDC’s Malaria Maps are another reference to help locate areas with malaria. Conduct an individualized risk assessment Prevention of malaria involves a balance between ensuring that all people who will be at risk of infection use ...

  6. A simple method for defining malaria seasonality

    PubMed Central

    2009-01-01

    Background There is currently no standard way of defining malaria seasonality, resulting in a wide range of definitions reported in the literature. Malaria cases show seasonal peaks in most endemic settings, and the choice and timing for optimal malaria control may vary by seasonality. A simple approach is presented to describe the seasonality of malaria, to aid localized policymaking and targeting of interventions. Methods A series of systematic literature reviews were undertaken to identify studies reporting on monthly data for full calendar years on clinical malaria, hospital admission with malaria and entomological inoculation rates (EIR). Sites were defined as having 'marked seasonality' if 75% or more of all episodes occurred in six or less months of the year. A 'concentrated period of malaria' was defined as the six consecutive months with the highest cumulative proportion of cases. A sensitivity analysis was performed based on a variety of cut-offs. Results Monthly data for full calendar years on clinical malaria, all hospital admissions with malaria, and entomological inoculation rates were available for 13, 18, and 11 sites respectively. Most sites showed year-round transmission with seasonal peaks for both clinical malaria and hospital admissions with malaria, with a few sites fitting the definition of 'marked seasonality'. For these sites, consistent results were observed when more than one outcome or more than one calendar year was available from the same site. The use of monthly EIR data was found to be of limited value when looking at seasonal variations of malaria transmission, particularly at low and medium intensity levels. Conclusion The proposed definition discriminated well between studies with 'marked seasonality' and those with less seasonality. However, a poor fit was observed in sites with two seasonal peaks. Further work is needed to explore the applicability of this definition on a wide-scale, using routine health information system data

  7. Evaluation of the malaria rapid diagnostic test SDFK90: detection of both PfHRP2 and Pf-pLDH

    PubMed Central

    2012-01-01

    Background Rapid diagnosis of Plasmodium falciparum infections is important because of the potentially fatal complications. SDFK90 is a recently marketed malaria rapid diagnostic test (RDT) targeting both histidine-rich protein 2 (PfHRP2) and P. falciparum-specific Plasmodium lactate dehydrogenase (Pf-pLDH). The present study evaluated its diagnostic accuracy. Methods SDFK90 was tested against a panel of stored whole blood samples (n= 591) obtained from international travellers suspected of malaria, including the four human Plasmodium species and Plasmodium negative samples. Microscopy was used as a reference method, corrected by PCR for species diagnosis. In addition, SDFK90 was challenged against 59 P. falciparum samples with parasite density ≥4% to assess the prozone effect (no or weak visible line on initial testing and a higher intensity upon 10-fold dilution). Results Overall sensitivity for the detection of P. falciparum was 98.5% and reached 99.3% at parasite densities >100/μl. There were significantly more PfHRP2 lines visible compared to Pf-pLDH (97.3% vs 86.9%), which was mainly absent at parasite densities <100/μl. Specificity of SDFK90 was 98.8%. No lot-to-lot variability was observed (p = 1.00) and test results were reproducible. A prozone effect was seen for the PfHRP2 line in 14/59 (23.7%) P. falciparum samples tested, but not for the Pf-pLDH line. Few minor shortcomings were observed in the kit’s packaging and information insert. Conclusions SDFK90 performed excellent for P. falciparum diagnosis. The combination of PfHRP2 and Pf-pLDH ensures a low detection threshold and counters potential problems of PfHRP2 detection such as gene deletions and the prozone effect. PMID:23107162

  8. Cerebral malaria

    PubMed Central

    Newton, C.; Hien, T. T.; White, N.

    2000-01-01

    Cerebral malaria may be the most common non-traumatic encephalopathy in the world. The pathogenesis is heterogenous and the neurological complications are often part of a multisystem dysfunction. The clinical presentation and pathophysiology differs between adults and children. Recent studies have elucidated the molecular mechanisms of pathogenesis and raised possible interventions. Antimalarial drugs, however, remain the only intervention that unequivocally affects outcome, although increasing resistance to the established antimalarial drugs is of grave concern. Artemisinin derivatives have made an impact on treatment, but other drugs may be required. With appropriate antimalarial drugs, the prognosis of cerebral malaria often depends on the management of other complications—for example, renal failure and acidosis. Neurological sequelae are increasingly recognised, but further research on the pathogenesis of coma and neurological damage is required to develop other ancillary treatments.

 PMID:10990500

  9. Imported malaria in United Arab Emirates: evaluation of a new DNA extraction technique using nested PCR.

    PubMed

    Sultan, Doaa M; Khalil, Marwa M; Abdouh, Ahmed S; Doleh, Wafaa F; Al Muthanna, Abdul Aziz M

    2009-09-01

    Local malaria transmission in the United Arab Emirates (UAE) came to an end in 1997. Nevertheless, UAE has been subjected to substantial importation of malaria cases from abroad, concerning both UAE nationals and immigrants from malarious countries with a total number of 2,119 cases in 2007. To evaluate a new DNA extraction technique using nested PCR, blood samples were collected from 132 individuals who presented to Infectious Diseases Department in Rashid Hospital, Dubai, and Central Department of Malaria Control with fever and persistent headache. Giemsa-stained blood films and ELISA test for malaria antibodies were carried out for detection of Plasmodium infection. Plasmodium infections were identified with the genus-specific primer set and species differentiation using nested PCR. A rapid procedure for diagnosis of malaria infections directly from dried blood spots using for the first time DNA extract from FTA Elute cards was evaluated in contrast to extraction techniques using FTA classic cards and rapid boiling technique. Our new simple technique for DNA extraction using FTA Elute cards was very sensitive giving a sensitivity of 100% compared to 94% using FTA classic cards and 62% in the rapid boiling technique. No complex preparation of blood samples was required prior to the amplification. The production cost of DNA isolation in our PCR assay was much less in comparable to that of other DNA extraction protocols. The nested PCR detected plasmodial infection and could differentiate P. falciparum from P. vivax, and also detected the mixed infection.

  10. Local pulmonary structure classification for computer-aided nodule detection

    NASA Astrophysics Data System (ADS)

    Bahlmann, Claus; Li, Xianlin; Okada, Kazunori

    2006-03-01

    We propose a new method of classifying the local structure types, such as nodules, vessels, and junctions, in thoracic CT scans. This classification is important in the context of computer aided detection (CAD) of lung nodules. The proposed method can be used as a post-process component of any lung CAD system. In such a scenario, the classification results provide an effective means of removing false positives caused by vessels and junctions thus improving overall performance. As main advantage, the proposed solution transforms the complex problem of classifying various 3D topological structures into much simpler 2D data clustering problem, to which more generic and flexible solutions are available in literature, and which is better suited for visualization. Given a nodule candidate, first, our solution robustly fits an anisotropic Gaussian to the data. The resulting Gaussian center and spread parameters are used to affine-normalize the data domain so as to warp the fitted anisotropic ellipsoid into a fixed-size isotropic sphere. We propose an automatic method to extract a 3D spherical manifold, containing the appropriate bounding surface of the target structure. Scale selection is performed by a data driven entropy minimization approach. The manifold is analyzed for high intensity clusters, corresponding to protruding structures. Techniques involve EMclustering with automatic mode number estimation, directional statistics, and hierarchical clustering with a modified Bhattacharyya distance. The estimated number of high intensity clusters explicitly determines the type of pulmonary structures: nodule (0), attached nodule (1), vessel (2), junction (>3). We show accurate classification results for selected examples in thoracic CT scans. This local procedure is more flexible and efficient than current state of the art and will help to improve the accuracy of general lung CAD systems.

  11. Vivax malaria

    PubMed Central

    Price, Ric N; Tjitra, Emiliana; Guerra, Carlos A; Yeung, Shunmay; White, Nicholas J; Anstey, Nicholas M

    2009-01-01

    Plasmodium vivax threatens almost 40% of the world’s population, resulting in 132 - 391 million clinical infections each year. Most of these cases originate from South East Asia and the Western Pacific, although a significant number also occur in Africa and South America. Although often regarded as causing a benign and self-limiting infection, there is increasing evidence that the overall burden, economic impact and severity of disease from P. vivax have been underestimated. Malaria control strategies have had limited success and are confounded by the lack of access to reliable diagnosis, emergence of multidrug resistant isolates and the parasite’s ability to transmit early in the course of disease and relapse from dormant liver stages at varying time intervals after the initial infection. Progress in reducing the burden of disease will require improved access to reliable diagnosis and effective treatment of both blood-stage and latent parasites, and more detailed characterization of the epidemiology, morbidity and economic impact of vivax malaria. Without these, vivax malaria will continue to be neglected by ministries of health, policy makers, researchers and funding bodies. PMID:18165478

  12. Expression and Evaluation of Recombinant Plasmodium knowlesi Merozoite Surface Protein-3 (MSP-3) for Detection of Human Malaria

    PubMed Central

    2016-01-01

    Malaria remains a major health threat in many parts of the globe and causes high mortality and morbidity with 214 million cases of malaria occurring globally in 2015. Recent studies have outlined potential diagnostic markers and vaccine candidates one of which is the merozoite surface protein (MSP)-3. In this study, novel recombinant Plasmodium knowlesi MSP-3 was cloned, expressed and purified in an Escherichia coli system. Subsequently, the recombinant protein was evaluated for its sensitivity and specificity. The recombinant pkMSP-3 protein reacted with sera from patients with P. knowlesi infection in both Western blot (61%) and ELISA (100%). Specificity-wise, pkMSP-3 did not react with healthy donor sera in either assay and only reacted with a few non-malarial parasitic patient sera in the ELISA assay (3 of 49). In conclusion, sensitivity and specificity of pkMSP-3 was found to be high in the ELISA and Western Blot assay and thus utilising both assays in tandem would provide the best sero-diagnostic result for P. knowlesi infection. PMID:27391270

  13. A systematic review of knowledge, attitudes and beliefs about malaria among the South Asian population

    PubMed Central

    Regmi, Krishna; Kunwar, Anju; Ortega, Leonard

    2016-01-01

    Background Malaria is one of the deadliest mosquito-borne diseases in the world. More than 80% of the total populations are at risk of malaria in the 22 countries in Asia and the Pacific. South Asia alone is home to an estimated 1.4 billion people at risk of contracting malaria. Despite the remarkable progress in reducing the burden of malaria, evidence of the disease based on knowledge of the social and cultural contexts from a South Asian perspective is limited. Our objective was to understand the knowledge, attitudes and beliefs about malaria in South Asian communities. Methodology We conducted a systematic literature review, searching six databases, between 1990 and 2015, focusing on knowledge, attitudes and beliefs about malaria in South Asia. Databases were searched using both ‘free terms’ and ‘index terms’ funnelled using Boolean operators and truncations. Inclusion and exclusion criteria were set, and included papers were scrutinised, employing a critical appraisal tool to find the best available evidences to support the study purpose. Results and discussion Evidence from 32 articles (26 quantitative, four qualitative and two mixed methods). General knowledge and awareness of the disease, its transmission, and control and preventative measures were generally found to be lacking amongst both the general public and healthcare professionals. In addition, the study shows that poor socio-economic factors – including limited access to services due to poor/limited availability – and issues of affordability are considered as major risk factors. Conclusion This review suggests the importance of increasing health awareness, mobilising the local or community healthcare professionals, for prevention as well as early detection and effective treatment of malaria among people who are at risk. Malaria is also a disease associated with poverty and socio-cultural factors; therefore, strong political will, wider partnerships between health and non-health sectors

  14. Infrared moving point target detection based on spatial-temporal local contrast filter

    NASA Astrophysics Data System (ADS)

    Deng, Lizhen; Zhu, Hu; Tao, Chao; Wei, Yantao

    2016-05-01

    Infrared moving point target detection is a challenging task. In this paper, we define a novel spatial local contrast (SLC) and a novel temporal local contrast (TLC) to enhance the target's contrast. Based on the defined spatial local contrast and temporal local contrast, we propose a simple but powerful spatial-temporal local contrast filter (STLCF) to detect moving point target from infrared image sequences. In order to verify the performance of spatial-temporal local contrast filter on detecting moving point target, different detection methods are used to detect the target from several infrared image sequences for comparison. The experimental results show that the proposed spatial-temporal local contrast filter has great superiority in moving point target detection.

  15. [Current malaria situation in Turkmenistan].

    PubMed

    Amangel'diev, K A

    2001-01-01

    administrative areas in ways of improving senior staff's skills in the laboratory diagnosis of malaria. The laboratory equipment which the country has received makes it possible to train high-level specialists and to equip its main malaria diagnosis centers with microscopes and reagents. The received insecticides and sprayers enable mosquitoes to be eliminated in an area of 960,000 sq. km (240 foci of infection): for this, our sincere thanks and gratitude are due to Dr. Guido Sabatinelli. Specialists teams have been created in each region by a decree of the Ministry of Health and Medical Industry to conduct mosquito elimination activities, with personal responsibility for their progress. Three-day vector control seminars have been held for disinfectors in all regions. We should stress that 5 extra posts have been created in the parasitology department of the Central Laboratory of Hygiene and Epidemiology, State Epidemiological Surveillance Service in order to strengthen preventive malaria control activities in Turkmenistan (organizational and methodological support for health facilities, staff training, etc.). To prevent the emergence of new breeding grounds for malaria vectors, the state system of health surveillance over the hygiene and technical status of water facilities and the rules governing their work have been reinforced. Local executive authorities do every effort to eliminate small, economically unprofitable water areas by draining, filling in or cleaning them. All existing and potential mosquito breeding grounds within a three-kilometer radius of any community were identified. These water areas were certified and their previous certifications analyzed, taking into account any changes and additional information which has become available about the area. Seasonal variations in the number of larvae and imagoes were monitored in the specimen areas of water and daytime resting sites. The existing vector species were identified and a list of the main species in all areas

  16. Timeliness of Malaria Surveillance System in Iran

    PubMed Central

    AKBARI, Hossein; MAJDZADEH, Reza; RAHIMI FOROUSHANI, Abbas; RAEISI, Ahmad

    2013-01-01

    Background: We aimed to evaluate the timeliness of reporting of malaria surveillance system and understanding the existing problems. Methods: The timeliness of malaria surveillance system of Iran was evaluated in four provinces of Iran including Sistan & Baluchistan, Hormozgan, Kerman (as provinces with local malaria transmission) and Khuzestan (without local malaria transmission). In this descriptive-analytic cross-sectional study two levels of Primary Health Care service providers including first level (Health Houses) and second level (Urban or Rural Health care units) were evaluated with regard to reporting of malaria surveillance system. Results: Forms number 1 (87% reported within one day) and number 2 (reporting median: 2 days) are reported from first level to second level, and forms number 4 (median: 4 days), number 3 (median: 6 days), number 7 (median: 9 days), number 5 (median: 11 days) and number 6 (median: 19 days) are reported from second level to the third level respectively in a shorter time. Independent variables such as distance, local malaria transmission level, and case finding type, are the factors affecting the reporting delay. Conclusion: Reporting in the first level compared to the second level is done with lower delay. In the areas where there is a deadline set for reporting, reporting is done more timely. Whatever number of malaria cases is decreased, sensitivity and subsequently timeliness reduced. It is recommended that the studies of timeliness be done with sensitivity and usefulness analysis of surveillance system. PMID:23515191

  17. Detection of Local/Regional Events in Kuwait Using Next-Generation Detection Algorithms

    SciTech Connect

    Gok, M. Rengin; Al-Jerri, Farra; Dodge, Douglas; Al-Enezi, Abdullah; Hauk, Terri; Mellors, R.

    2014-12-10

    Seismic networks around the world use conventional triggering algorithms to detect seismic signals in order to locate local/regional seismic events. Kuwait National Seismological Network (KNSN) of Kuwait Institute of Scientific Research (KISR) is operating seven broad-band and short-period three-component stations in Kuwait. The network is equipped with Nanometrics digitizers and uses Antelope and Guralp acquisition software for processing and archiving the data. In this study, we selected 10 days of archived hourly-segmented continuous data of five stations (Figure 1) and 250 days of continuous recording at MIB. For the temporary deployment our selection criteria was based on KNSN catalog intensity for the period of time we test the method. An autonomous event detection and clustering framework is employed to test a more complete catalog of this short period of time. The goal is to illustrate the effectiveness of the technique and pursue the framework for longer period of time.

  18. Malaria in Brazil: an overview

    PubMed Central

    2010-01-01

    Malaria is still a major public health problem in Brazil, with approximately 306 000 registered cases in 2009, but it is estimated that in the early 1940s, around six million cases of malaria occurred each year. As a result of the fight against the disease, the number of malaria cases decreased over the years and the smallest numbers of cases to-date were recorded in the 1960s. From the mid-1960s onwards, Brazil underwent a rapid and disorganized settlement process in the Amazon and this migratory movement led to a progressive increase in the number of reported cases. Although the main mosquito vector (Anopheles darlingi) is present in about 80% of the country, currently the incidence of malaria in Brazil is almost exclusively (99,8% of the cases) restricted to the region of the Amazon Basin, where a number of combined factors favors disease transmission and impair the use of standard control procedures. Plasmodium vivax accounts for 83,7% of registered cases, while Plasmodium falciparum is responsible for 16,3% and Plasmodium malariae is seldom observed. Although vivax malaria is thought to cause little mortality, compared to falciparum malaria, it accounts for much of the morbidity and for huge burdens on the prosperity of endemic communities. However, in the last few years a pattern of unusual clinical complications with fatal cases associated with P. vivax have been reported in Brazil and this is a matter of concern for Brazilian malariologists. In addition, the emergence of P. vivax strains resistant to chloroquine in some reports needs to be further investigated. In contrast, asymptomatic infection by P. falciparum and P. vivax has been detected in epidemiological studies in the states of Rondonia and Amazonas, indicating probably a pattern of clinical immunity in both autochthonous and migrant populations. Seropidemiological studies investigating the type of immune responses elicited in naturally-exposed populations to several malaria vaccine candidates in

  19. Think locally, act locally: Detection of small, medium-sized, and large communities in large networks

    NASA Astrophysics Data System (ADS)

    Jeub, Lucas G. S.; Balachandran, Prakash; Porter, Mason A.; Mucha, Peter J.; Mahoney, Michael W.

    2015-01-01

    networks, the output of locally biased methods that focus on communities that are centered around a given seed node (or set of seed nodes) might have better conceptual grounding and greater practical utility than the output of global community-detection methods. They also illustrate structural properties that are important to consider in the development of better benchmark networks to test methods for community detection.

  20. Automated Terrestrial EMI Emitter Detection, Classification, and Localization

    NASA Astrophysics Data System (ADS)

    Stottler, R.; Bowman, C.; Bhopale, A.

    2016-09-01

    Clear operating spectrum at ground station antenna locations is critically important for communicating with, commanding, controlling, and maintaining the health of satellites. Electro Magnetic Interference (EMI) can interfere with these communications so tracking down the source of EMI is extremely important to prevent it from occurring in the future. The Terrestrial RFI-locating Automation with CasE based Reasoning (TRACER) system is designed to automate terrestrial EMI emitter localization and identification, providing improved space situational awareness, realizing significant manpower savings, dramatically shortening EMI response time, providing capabilities for the system to evolve without programmer involvement, and offering increased support for adversarial scenarios (e.g. jamming). TRACER has been prototyped and tested with real data (amplitudes versus frequency over time) for both satellite communication antennas and sweeping Direction Finding (DF) antennas located near them. TRACER monitors the satellite communication and DF antenna signals to detect and classify EMI using neural network technology trained on past cases of both normal communications and EMI events. Based on details of the signal (its classification, its direction and strength, etc.) one or more cases of EMI investigation methodologies are retrieved, represented as graphical behavior transition networks (BTNs), which very naturally represent the flowchart-like process often followed by experts in time pressured situations, are intuitive to SMEs, and easily edited by them. The appropriate actions, as determined by the BTN are executed and the resulting data processed by Bayesian Networks to update the probabilities of the various possible platforms and source types of the EMI. Bearing sweep of the EMI is used to determine if the EMI's platform is aerial, a ground vehicle or ship, or stationary. If moving, the Friis transmission equation is used to plot the emitter's location and compare it

  1. Transdermal Diagnosis of Malaria Using Vapor Nanobubbles

    PubMed Central

    Lukianova-Hleb, Ekaterina; Bezek, Sarah; Szigeti, Reka; Khodarev, Alexander; Kelley, Thomas; Hurrell, Andrew; Berba, Michail; Kumar, Nirbhay; D’Alessandro, Umberto

    2015-01-01

    A fast, precise, noninvasive, high-throughput, and simple approach for detecting malaria in humans and mosquitoes is not possible with current techniques that depend on blood sampling, reagents, facilities, tedious procedures, and trained personnel. We designed a device for rapid (20-second) noninvasive diagnosis of Plasmodium falciparum infection in a malaria patient without drawing blood or using any reagent. This method uses transdermal optical excitation and acoustic detection of vapor nanobubbles around intraparasite hemozoin. The same device also identified individual malaria parasite–infected Anopheles mosquitoes in a few seconds and can be realized as a low-cost universal tool for clinical and field diagnoses. PMID:26079141

  2. Transdermal Diagnosis of Malaria Using Vapor Nanobubbles.

    PubMed

    Lukianova-Hleb, Ekaterina; Bezek, Sarah; Szigeti, Reka; Khodarev, Alexander; Kelley, Thomas; Hurrell, Andrew; Berba, Michail; Kumar, Nirbhay; D'Alessandro, Umberto; Lapotko, Dmitri

    2015-07-01

    A fast, precise, noninvasive, high-throughput, and simple approach for detecting malaria in humans and mosquitoes is not possible with current techniques that depend on blood sampling, reagents, facilities, tedious procedures, and trained personnel. We designed a device for rapid (20-second) noninvasive diagnosis of Plasmodium falciparum infection in a malaria patient without drawing blood or using any reagent. This method uses transdermal optical excitation and acoustic detection of vapor nanobubbles around intraparasite hemozoin. The same device also identified individual malaria parasite-infected Anopheles mosquitoes in a few seconds and can be realized as a low-cost universal tool for clinical and field diagnoses.

  3. Malaria infection and human evolution.

    PubMed

    Sabbatani, Sergio; Manfredi, Roberto; Fiorino, Sirio

    2010-03-01

    During the evolution of the genus Homo, with regard to the species habilis, erectus and sapiens, malaria has played a key biological role in influencing human development. The plasmodia causing malaria have evolved in two ways, in biological and phylogenetic terms: Plasmodium vivax, Plasmodium malariae and Plasmodium ovale appear to have either coevolved with human mankind, or encountered human species during the most ancient phases of Homo evolution; on the other hand, Plasmodium falciparum has been transmitted to humans by monkeys in a more recent period, probably between the end of the Mesolithic and the beginning of the Neolithic age. The authors show both direct and indirect biomolecular evidence of malarial infection, detected in buried subjects, dating to ancient times and brought to light in the course of archaeological excavations in major Mediterranean sites. In this review of the literature the authors present scientific evidence confirming the role of malaria in affecting the evolution of populations in Mediterranean countries. The people living in several different Mediterranean regions, the cradle of western civilization, have been progressively influenced by malaria in the course of the spread of this endemic disease in recent millennia. In addition, populations affected by endemic malaria progressively developed cultural, dietary and behavioural adaptation mechanisms, which contributed to diminish the risk of disease. These habits were probably not fully conscious. Nevertheless it may be thought that both these customs and biological modifications, caused by malarial plasmodia, favoured the emergence of groups of people with greater resistance to malaria. All these factors have diminished the unfavourable demographic impact of the disease, also positively influencing the general development and growth of civilization.

  4. Prevalence of gestational, placental and congenital malaria in north-west Colombia

    PubMed Central

    2013-01-01

    Background The frequency of pregnancy-associated malaria is increasingly being documented in American countries. In Colombia, with higher frequency of Plasmodium vivax over Plasmodium falciparum infection, recent reports confirmed gestational malaria as a serious public health problem. Thick smear examination is the gold standard to diagnose malaria in endemic settings, but in recent years, molecular diagnostic methods have contributed to elucidate the dimension of the problem of gestational malaria. The study was aimed at exploring the prevalence of gestational, placental and congenital malaria in women who delivered at the local hospitals of north-west Colombia, between June 2008 and April 2011. Methods A group of 129 parturient women was selected to explore the prevalence of gestational, placental and congenital malaria in a descriptive, prospective and transversal (prevalence) design. Diagnosis was based on the simultaneous application of two independent diagnostic tests: microscopy of thick blood smears and a polymerase chain reaction assay (PCR). Results The prevalence of gestational malaria (thick smear /PCR) was 9.1%/14.0%; placental malaria was 3.3%/16.5% and congenital malaria was absent. A history of gestational malaria during the current pregnancy was significantly associated with gestational malaria at delivery. Plasmodium vivax caused 65% of cases of gestational malaria, whereas P. falciparum caused most cases of placental malaria. Conclusions Gestational and placental malaria are a serious problem in the region, but the risk of congenital malaria is low. A history of malaria during pregnancy may be a practical indicator of infection at delivery. PMID:24053184

  5. LOCI: Fast Outlier Detection Using the Local Correlation Integral

    DTIC Science & Technology

    2002-11-01

    Density-based approach. This was proposed by M. Breunig , et al. [BKNS00]. It relies on the local outlier factor (LOF) of each object, which depends...VLDB, pages 299–310, 1995. [BKNS00] M.M. Breunig , H.P. Kriegel, R.T. Ng, and J. Sander. Lof: Identifying density-based local outliers. In Proc

  6. Monitoring of Plasmodium infection in humans and potential vectors of malaria in a newly emerged focus in southern Iran.

    PubMed

    Kalantari, Mohsen; Soltani, Zahra; Ebrahimi, Mostafa; Yousefi, Masoud; Amin, Masoumeh; Shafiei, Ayda; Azizi, Kourosh

    2017-02-01

    Despite control programs, which aim to eliminate malaria from Iran by 2025, transmission of malaria has not been removed from the country. This study aimed to monitor malaria from asymptomatic parasitaemia and clinical cases from about one year of active case surveillance and potential vectors of malaria in the newly emerged focus of Mamasani and Rostam, southern Iran during 2014-2015. Samples were collected and their DNAs were extracted for Polymerase Chain Reaction (PCR) assay using specific primers for detection of Plasmodium species. The Annual Parasite Incidence rate (API) was three cases per 1,000 population from 2,000 individuals in three villages. Parasites species were detected in 9 out of the 4,000 blood smear samples among which, 6 cases were indigenous and had no history of travels to endemic areas of malaria. Also, the prevalence rate of asymptomatic parasites was about 0.3%. Overall, 1073 Anopheles spp. were caught from 9 villages. Totally, 512 female samples were checked by PCR, which indicated that none of them was infected with Plasmodium. Despite new malaria local transmission in humans in Mamasani and Rostam districts, no infection with Plasmodium was observed in Anopheles species. Because of neighboring of the studied area to the re-emerged focus in Fars province (Kazerun) and important endemic foci of malaria in other southern provinces, such as Hormozgan and Kerman, monitoring of the vectors and reservoir hosts of Plasmodium species would be unavoidable. Application of molecular methods, such as PCR, can simplify access to the highest level of accuracy in malaria researches.

  7. Defining the Global Spatial Limits of Malaria Transmission in 2005

    PubMed Central

    Guerra, C.A.; Snow, R.W.; Hay, S.I.

    2011-01-01

    There is no accurate contemporary global map of the distribution of malaria. We show how guidelines formulated to advise travellers on appropriate chemoprophylaxis for areas of reported Plasmodium falciparum and Plasmodium vivax malaria risk can be used to generate crude spatial limits. We first review and amalgamate information on these guidelines to define malaria risk at national and sub-national administrative boundary levels globally. We then adopt an iterative approach to reduce these extents by applying a series of biological limits imposed by altitude, climate and population density to malaria transmission, specific to the local dominant vector species. Global areas of, and population at risk from, P. falciparum and often-neglected P. vivax malaria are presented for 2005 for all malaria endemic countries. These results reveal that more than 3 billion people were at risk of malaria in 2005. PMID:16647970

  8. Vaccines against malaria.

    PubMed

    Ouattara, Amed; Laurens, Matthew B

    2015-03-15

    Despite global efforts to control malaria, the illness remains a significant public health threat. Currently, there is no licensed vaccine against malaria, but an efficacious vaccine would represent an important public health tool for successful malaria elimination. Malaria vaccine development continues to be hindered by a poor understanding of antimalarial immunity, a lack of an immune correlate of protection, and the genetic diversity of malaria parasites. Current vaccine development efforts largely target Plasmodium falciparum parasites in the pre-erythrocytic and erythrocytic stages, with some research on transmission-blocking vaccines against asexual stages and vaccines against pregnancy-associated malaria. The leading pre-erythrocytic vaccine candidate is RTS,S, and early results of ongoing Phase 3 testing show overall efficacy of 46% against clinical malaria. The next steps for malaria vaccine development will focus on the design of a product that is efficacious against the highly diverse strains of malaria and the identification of a correlate of protection against disease.

  9. Localized surface plasmon resonance mercury detection system and methods

    DOEpatents

    James, Jay; Lucas, Donald; Crosby, Jeffrey Scott; Koshland, Catherine P.

    2016-03-22

    A mercury detection system that includes a flow cell having a mercury sensor, a light source and a light detector is provided. The mercury sensor includes a transparent substrate and a submonolayer of mercury absorbing nanoparticles, e.g., gold nanoparticles, on a surface of the substrate. Methods of determining whether mercury is present in a sample using the mercury sensors are also provided. The subject mercury detection systems and methods find use in a variety of different applications, including mercury detecting applications.

  10. Epidemiology and Clinical Burden of Malaria in the War-Torn Area, Orakzai Agency in Pakistan

    PubMed Central

    Karim, Asad Mustafa; Hussain, Irfan; Malik, Sumera Kausar; Lee, Jung Hun; Cho, Ill Hwan; Kim, Young Bae; Lee, Sang Hee

    2016-01-01

    Background Military conflict has been a major challenge in the detection and control of emerging infectious diseases such as malaria. It poses issues associated with enhancing emergence and transmission of infectious diseases by destroying infrastructure and collapsing healthcare systems. The Orakzai agency in Pakistan has witnessed a series of intense violence and destruction. Military conflicts and instability in Afghanistan have resulted in the migration of refugees into the area and possible introduction of many infectious disease epidemics. Due to the ongoing violence and Talibanization, it has been a challenge to conduct an epidemiological study. Methodology/Principal Findings All patients were sampled within the transmission season. After a detailed clinical investigation of patients, data were recorded. Baseline venous blood samples were taken for microscopy and nested polymerase chain reaction (nPCR) analysis. Plasmodium species were detected using nested PCR (nPCR) and amplification of the small subunit ribosomal ribonucleic acid (ssrRNA) genes using the primer pairs. We report a clinical assessment of the epidemic situation of malaria caused by Plasmodium vivax (86.5%) and Plasmodium falciparum (11.79%) infections with analysis of complications in patients such as decompensated shock (41%), anemia (8.98%), hypoglycaemia (7.3%), multiple convulsions (6.7%), hyperpyrexia (6.17%), jaundice (5%), and hyperparasitaemia (4.49%). Conclusions/Significance This overlooked distribution of P. vivax should be considered by malaria control strategy makers in the world and by the Government of Pakistan. In our study, children were the most susceptible population to malaria infection while they were the least expected to use satisfactory prevention strategies in such a war-torn deprived region. Local health authorities should initiate malaria awareness programs in schools and malaria-related education should be further promoted at the local level reaching out to both

  11. Detecting measurement-induced relative-position localization

    NASA Astrophysics Data System (ADS)

    Knott, P. A.; Sindt, J.; Dunningham, J. A.

    2013-05-01

    The theory of decoherence explains how classicality emerges from an underlying quantum reality. An additional interpretation to this has been proposed in which scattering events induce the localization of relative observables (Rau et al 2003 Science 301 1081). An interesting consequence of this process is that it involves the build-up of certain robust entanglements between the observables being localized. To date the weakness of this interpretation has been the lack of a clear experimental signature that allows it to be tested. Here we provide a simple experimentally accessible scheme that enables just that. We also discuss a Bayesian technique that could, in principle, allow experiments to confirm the localization to any desired degree of accuracy and we present precision requirements that are achievable with current experiments. Finally, we extend the scheme from its initial one dimensional proof of principle to the more real world scenario of three dimensional localization.

  12. Prophylaxis of Malaria

    PubMed Central

    Schwartz, Eli

    2012-01-01

    Malaria prevention in travelers to endemic areas remains dependent principally on chemoprophylaxis. Although malaria chemoprophylaxis refers to all malaria species, a distinction should be drawn between falciparum malaria prophylaxis and the prophylaxis of the relapsing malaria species (vivax & ovale). While the emergence of drug resistant strains, as well as the costs and adverse reactions to medications, complicate falciparum prophylaxis use, there are virtually no drugs available for vivax prophylaxis, beside of primaquine. Based on traveler’s malaria data, a revised recommendation for using chemoprophylaxis in low risk areas should be considered. PMID:22811794

  13. UK malaria treatment guidelines 2016.

    PubMed

    Lalloo, David G; Shingadia, Delane; Bell, David J; Beeching, Nicholas J; Whitty, Christopher J M; Chiodini, Peter L

    2016-06-01

    1.Malaria is the tropical disease most commonly imported into the UK, with 1300-1800 cases reported each year, and 2-11 deaths. 2. Approximately three quarters of reported malaria cases in the UK are caused by Plasmodium falciparum, which is capable of invading a high proportion of red blood cells and rapidly leading to severe or life-threatening multi-organ disease. 3. Most non-falciparum malaria cases are caused by Plasmodium vivax; a few cases are caused by the other species of plasmodium: Plasmodium ovale, Plasmodium malariae or Plasmodium knowlesi. 4. Mixed infections with more than one species of parasite can occur; they commonly involve P. falciparum with the attendant risks of severe malaria. 5. There are no typical clinical features of malaria; even fever is not invariably present. Malaria in children (and sometimes in adults) may present with misleading symptoms such as gastrointestinal features, sore throat or lower respiratory complaints. 6. A diagnosis of malaria must always be sought in a feverish or sick child or adult who has visited malaria-endemic areas. Specific country information on malaria can be found at http://travelhealthpro.org.uk/. P. falciparum infection rarely presents more than six months after exposure but presentation of other species can occur more than a year after exposure. 7. Management of malaria depends on awareness of the diagnosis and on performing the correct diagnostic tests: the diagnosis cannot be excluded until more than one blood specimen has been examined. Other travel related infections, especially viral haemorrhagic fevers, should also be considered. 8. The optimum diagnostic procedure is examination of thick and thin blood films by an expert to detect and speciate the malarial parasites. P. falciparum and P. vivax (depending upon the product) malaria can be diagnosed almost as accurately using rapid diagnostic tests (RDTs) which detect plasmodial antigens. RDTs for other Plasmodium species are not as reliable. 9

  14. Utilization of combined remote sensing techniques to detect environmental variables influencing malaria vector densities in rural West Africa

    PubMed Central

    2012-01-01

    Introduction The use of remote sensing has found its way into the field of epidemiology within the last decades. With the increased sensor resolution of recent and future satellites new possibilities emerge for high resolution risk modeling and risk mapping. Methods A SPOT 5 satellite image, taken during the rainy season 2009 was used for calculating indices by combining the image's spectral bands. Besides the widely used Normalized Difference Vegetation Index (NDVI) other indices were tested for significant correlation against field observations. Multiple steps, including the detection of surface water, its breeding appropriateness for Anopheles and modeling of vector imagines abundance, were performed. Data collection on larvae, adult vectors and geographic parameters in the field, was amended by using remote sensing techniques to gather data on altitude (Digital Elevation Model = DEM), precipitation (Tropical Rainfall Measurement Mission = TRMM), land surface temperatures (LST). Results The DEM derived altitude as well as indices calculations combining the satellite's spectral bands (NDTI = Normalized Difference Turbidity Index, NDWI Mac Feeters = Normalized Difference Water Index) turned out to be reliable indicators for surface water in the local geographic setting. While Anopheles larvae abundance in habitats is driven by multiple, interconnected factors - amongst which the NDVI - and precipitation events, the presence of vector imagines was found to be correlated negatively to remotely sensed LST and positively to the cumulated amount of rainfall in the preceding 15 days and to the Normalized Difference Pond Index (NDPI) within the 500 m buffer zone around capture points. Conclusions Remotely sensed geographical and meteorological factors, including precipitations, temperature, as well as vegetation, humidity and land cover indicators could be used as explanatory variables for surface water presence, larval development and imagines densities. This modeling

  15. Prevention of Malaria Resurgence in Greece through the Association of Mass Drug Administration (MDA) to Immigrants from Malaria-Endemic Regions and Standard Control Measures

    PubMed Central

    Tseroni, Maria; Baka, Agoritsa; Kapizioni, Christina; Snounou, Georges; Tsiodras, Sotirios; Charvalakou, Maria; Georgitsou, Maria; Panoutsakou, Maria; Psinaki, Ioanna; Tsoromokou, Maria; Karakitsos, George; Pervanidou, Danai; Vakali, Annita; Mouchtouri, Varvara; Georgakopoulou, Theano; Mamuris, Zissis; Papadopoulos, Nikos; Koliopoulos, George; Badieritakis, Evangelos; Diamantopoulos, Vasilis; Tsakris, Athanasios; Kremastinou, Jenny; Hadjichristodoulou, Christos

    2015-01-01

    Greece was declared malaria-free in 1974 after a long antimalarial fight. In 2011–2012, an outbreak of P. vivax malaria was reported in Evrotas, an agricultural area in Southern Greece, where a large number of immigrants from endemic countries live and work. A total of 46 locally acquired and 38 imported malaria cases were detected. Despite a significant decrease of the number of malaria cases in 2012, a mass drug administration (MDA) program was considered as an additional measure to prevent reestablishment of the disease in the area. During 2013 and 2014, a combination of 3-day chloroquine and 14-day primaquine treatment was administered under direct observation to immigrants living in the epicenter of the 2011 outbreak in Evrotas. Adverse events were managed and recorded on a daily basis. The control measures implemented since 2011 continued during the period of 2013–2014 as a part of a national integrated malaria control program that included active case detection (ACD), vector control measures and community education. The MDA program was started prior to the transmission periods (from May to December). One thousand ninety four (1094) immigrants successfully completed the treatment, corresponding to 87.3% coverage of the target population. A total of 688 adverse events were recorded in 397 (36.2%, 95% C.I.: 33.4–39.1) persons, the vast majority minor, predominantly dizziness and headache for chloroquine (284 events) and abdominal pain (85 events) for primaquine. A single case of primaquine-induced hemolysis was recorded in a person whose initial G6PD test proved incorrect. No malaria cases were recorded in Evrotas, Laconia, in 2013 and 2014, though three locally acquired malaria cases were recorded in other regions of Greece in 2013. Preventive antimalarial MDA to a high-risk population in a low transmission setting appears to have synergized with the usual antimalarial activities to achieve malaria elimination. This study suggests that judicious use of

  16. Prevention of Malaria Resurgence in Greece through the Association of Mass Drug Administration (MDA) to Immigrants from Malaria-Endemic Regions and Standard Control Measures.

    PubMed

    Tseroni, Maria; Baka, Agoritsa; Kapizioni, Christina; Snounou, Georges; Tsiodras, Sotirios; Charvalakou, Maria; Georgitsou, Maria; Panoutsakou, Maria; Psinaki, Ioanna; Tsoromokou, Maria; Karakitsos, George; Pervanidou, Danai; Vakali, Annita; Mouchtouri, Varvara; Georgakopoulou, Theano; Mamuris, Zissis; Papadopoulos, Nikos; Koliopoulos, George; Badieritakis, Evangelos; Diamantopoulos, Vasilis; Tsakris, Athanasios; Kremastinou, Jenny; Hadjichristodoulou, Christos

    2015-11-01

    Greece was declared malaria-free in 1974 after a long antimalarial fight. In 2011-2012, an outbreak of P. vivax malaria was reported in Evrotas, an agricultural area in Southern Greece, where a large number of immigrants from endemic countries live and work. A total of 46 locally acquired and 38 imported malaria cases were detected. Despite a significant decrease of the number of malaria cases in 2012, a mass drug administration (MDA) program was considered as an additional measure to prevent reestablishment of the disease in the area. During 2013 and 2014, a combination of 3-day chloroquine and 14-day primaquine treatment was administered under direct observation to immigrants living in the epicenter of the 2011 outbreak in Evrotas. Adverse events were managed and recorded on a daily basis. The control measures implemented since 2011 continued during the period of 2013-2014 as a part of a national integrated malaria control program that included active case detection (ACD), vector control measures and community education. The MDA program was started prior to the transmission periods (from May to December). One thousand ninety four (1094) immigrants successfully completed the treatment, corresponding to 87.3% coverage of the target population. A total of 688 adverse events were recorded in 397 (36.2%, 95% C.I.: 33.4-39.1) persons, the vast majority minor, predominantly dizziness and headache for chloroquine (284 events) and abdominal pain (85 events) for primaquine. A single case of primaquine-induced hemolysis was recorded in a person whose initial G6PD test proved incorrect. No malaria cases were recorded in Evrotas, Laconia, in 2013 and 2014, though three locally acquired malaria cases were recorded in other regions of Greece in 2013. Preventive antimalarial MDA to a high-risk population in a low transmission setting appears to have synergized with the usual antimalarial activities to achieve malaria elimination. This study suggests that judicious use of MDA can

  17. Malaria infection and life-style factors among hilltribes along the Thai-Myanmar border area, northern Thailand.

    PubMed

    Pichainarong, Natchaporn; Chaveepojnkamjorn, Wisit

    2004-12-01

    A cross sectional study was conducted between January, 2001 and June, 2002 to determine the life-style factors associated with malaria infection among hilltribes in the Chiang Rai Province, Mae Fah Luang district located along the Thai-Myanmar border, northern Thailand. The data collected were a thick blood film examination and a face-to-face interview using a local language interviewer at a mobile clinic or a home visit. The chi-square test, odds ratio, 95% confidence interval and multiple logistic regression were used as data analysis. P. vivax (61.3%) was detected more than P falciparum (38.2%). Parasitic infection was seen in 45.8% of a total of 417 blood examinations. The study area was in a valley covered with forests and small streams, which was ideal for a malaria epidemic. The communities were distributed along different ethnic groups. There were 12 ethnic groups, dominated by the Muser, Eko, and Akha tribes (60-70%). The risk factors included living or working in the forest, accompanying their family during movement through the forest, age < or =14 years (40.9%), poor knowledge of how to protect against malaria (75-80%), and unavailability of protection against malaria via long sleeved clothes, topical repellents, and insecticide treated nets (use and carry), which resulted in an increased exposure to malaria and risk for malaria infection.

  18. Detection of localized fatigue damage in steel by thermography

    NASA Astrophysics Data System (ADS)

    Medgenberg, Justus; Ummenhofer, Thomas

    2007-04-01

    Fatigue damage of unalloyed steels in the high cycle regime is governed by localized cyclic plastic deformations and subsequent crack initiation. The extent of early microplastic deformations depends on the applied stress level, stress concentration at macroscopic notches, surface treatment, residual stresses etc. The onset of a nonlinear material response can be regarded as an early indicator of fatigue damage. During fatigue loading thermoelastic coupling and thermoplastic dissipation cause characteristic temperature variations in tested specimens which have been assessed by a highly sensitive infrared camera. A specialized data processing method in the time domain has been developed which allows to separate the different contributions to the measured temperature signal. In contrast to other methods - as e.g. measuring the rise of mean temperature during fatigue loading - the proposed methodology is based on measurements during the stabilized temperature regimen and offers very high spatial resolution of localized phenomena. Investigations have been made on mildly notched cylindrical and also on welded specimens. The results confirm the close relation between the local temperature signal and typical fatigue phenomena. The new methodology allows for a much better localization and quantification of effects as cyclic plasticity, crack initiation, crack growth etc. The following paper presents considerations and experimental results of an application of thermography to the local assessment of fatigue damage.

  19. [WHO's malaria program Roll Back Malaria].

    PubMed

    Myrvang, B; Godal, T

    2000-05-30

    Malaria is one of the main health problems in the world with 300-500 millions cases yearly and about one million deaths, mainly children in Sub-Saharan Africa. In the 1990s the malaria problem in Africa has increased, although we have methods to control the disease. In 1998 the new secretary general of WHO, Gro Harlem Brundtland, established the Roll Back Malaria programme, with the aim to markedly reduce malaria morbidity and mortality. Governments in malaria-affected countries have to take the lead in Roll Back Malaria. Their health systems must be improved and malaria control integrated into the general health system, and the methods available for prevention and treatment have to be intensified and improved. At the same time, Roll Back Malaria will encourage and promote malaria research which hopefully will result in new medicines, vaccines and other tools which will improve the chances of reducing malaria-related deaths and suffering. Roll Back Malaria is a cabinet project within the WHO, and the organisation has a key role as manager, co-ordinator and monitor of the project. However, it depends for resources on international support and commitment from other UN bodies, the World Bank, governments in the western world, pharmaceutical industry, philanthropists and other sources. At present an optimistic view prevails, and the preliminary aim, to halve the malaria mortality by the year 2010, seems realistic even with the control methods of today. However, if research efforts result in new and better tools to combat the disease, the task will definitely be easier.

  20. Importation of malaria into the USSR from Afghanistan, 1981-89.

    PubMed Central

    Sergiev, V. P.; Baranova, A. M.; Orlov, V. S.; Mihajlov, L. G.; Kouznetsov, R. L.; Neujmin, N. I.; Arsenieva, L. P.; Shahova, M. A.; Glagoleva, L. A.; Osipova, M. M.

    1993-01-01

    Between 1981 and 1989, a total of 7683 cases of Plasmodium vivax [corrected] malaria were imported into the USSR from Afghanistan, mainly by demobilized military personnel. For 23.8% of these cases the clinical manifestations appeared within a month of returning to the USSR, for 22.5% after 1-3 months, for 20% after 4-6 months, for 2% after > 1 year, and for 0.6% after > 2 years. For 13 patients the clinical manifestations of malaria appeared 3 years after returning from Afghanistan (up to 38 months). Nearly 69% of the patients did not take malaria prophylaxis at all while they were in Afghanistan, and 19% took chloroquine irregularly. Only 12.5% of the patients received a full course of prophylactic treatment with primaquine before leaving Afghanistan. A total of 56% of the cases were detected during the period most favourable for malaria transmission in the USSR (May-September) and of these, half were imported into formerly malarious areas of the country. Activation of a surveillance system greatly reduced the consequences of the massive importation of malaria, to which the local vectors were susceptible. PMID:8324858

  1. Battling malaria iceberg incorporating strategic reforms in achieving Millennium Development Goals & malaria elimination in India

    PubMed Central

    Sharma, V. P.

    2012-01-01

    Malaria control in India has occupied high priority in health sector consuming major resources of the Central and State governments. Several new initiatives were launched from time to time supported by foreign aids but malaria situation has remained static and worsened in years of good rainfall. At times malaria relented temporarily but returned with vengeance at the local, regional and national level, becoming more resilient by acquiring resistance in the vectors and the parasites. National developments to improve the economy, without health impact assessment, have had adverse consequences by providing enormous breeding grounds for the vectors that have become refractory to interventions. As a result, malaria prospers and its control is in dilemma, as finding additional resources is becoming difficult with the ongoing financial crisis. Endemic countries must contribute to make up the needed resources, if malaria is to be contained. Malaria control requires long term planning, one that will reduce receptivity and vulnerability, and uninterrupted financial support for sustained interventions. While this seems to be a far cry, the environment is becoming more receptive for vectors, and epidemics visit the country diverting major resources in their containment, e.g. malaria, dengue and dengue haemorrhagic fevers, and Chikungunya virus infection. In the last six decades malaria has taken deep roots and diversified into various ecotypes, the control of these ecotypes requires local knowledge about the vectors and the parasites. In this review we outline the historical account of malaria and methods of control that have lifted the national economy in many countries. While battles against malaria should continue at the local level, there is a need for large scale environmental improvement. Global Fund for AIDS, Tuberculosis and Malaria has provided huge funds for malaria control worldwide touching US$ 2 billion in 2011. Unfortunately it is likely to decline to US$ 1

  2. Malaria (For Parents)

    MedlinePlus

    ... period for malaria is the time between the mosquito bite and the release of parasites from the ... Health authorities try to prevent malaria by using mosquito-control programs aimed at killing mosquitoes that carry ...

  3. Malaria (For Parents)

    MedlinePlus

    ... it is passed from person to person (from mother to child in "congenital malaria," or through blood ... risk for malaria. Your doctor can give your family anti-malarial drugs to prevent the disease, which ...

  4. Local Leak Detection and Health Monitoring of Pressurized Tanks

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt; Witherow, William; Korman, Valentin; Sinko, John; Hendrickson, Adam

    2011-01-01

    An optical gas-detection sensor safely monitors pressurized systems (such as cryogenic tanks) and distribution systems for leaks. This sensor system is a fiber-coupled, solid optical body interferometer that allows for the miniaturized sensing element of the device to be placed in the smallest of recesses, and measures a wide range of gas species and densities (leaks). The deflection of the fringe pattern is detected and recorded to yield the time-varying gas density in the gap. This technology can be used by manufacturers or storage facilities with toxic, hazardous, or explosive gases. The approach is to monitor the change in the index of refraction associated with low-level gas leaks into a vacuum environment. The completion of this work will provide NASA with an enabling capability to detect gas system leaks in space, and to verify that pressurized systems are in a safe (i.e. non-leaking) condition during manned docking and transit operations. By recording the output of the sensor, a time-history of the leak can be constructed to indicate its severity. Project risk is mitigated by having several interferometric geometries and detection techniques available, each potentially leveraging hardware and lessons learned to enhance detectability.

  5. Radar Monitoring of Wetlands for Malaria Control

    NASA Technical Reports Server (NTRS)

    Pope, Kevin O.

    1997-01-01

    Malaria is perhaps the most serious human disease problem. It inflicts millions worldwide and is on the rise in many countries where it was once under control. This rise is in part due to the high costs, both economic and environmental, of current control programs. The search for more cost-effective means to combat malaria has focussed attention on new technologies, one of which is remote sensing. Remote sensing has become an important tool in the effort to control a variety of diseases worldwide and malaria is perhaps one of the most promising. This study is part of the malaria control effort in the Central American country of Belize, which has experienced a resurgence of malaria in the last two decades. The proposed project is a feasibility study of the use of Radarsat (and other similar radar systems) to monitor seasonal changes in the breeding sites of the anopheline mosquito, which is responsible for malaria transmission. We propose that spatial and temporal changes in anopheline mosquito production can be predicted by sensing where and when their breeding sites are flooded. Timely knowledge of anopheline mosquito production is a key factor in control efforts. Such knowledge can be used by local control agencies to direct their limited resources to selected areas and time periods when the human population is at greatest risk. Radar is a key sensor in this application because frequent cloud cover during the peak periods of malaria transmission precludes the use of optical sensors.

  6. Spatial targeting of interventions against malaria.

    PubMed Central

    Carter, R.; Mendis, K. N.; Roberts, D.

    2000-01-01

    Malaria transmission is strongly associated with location. This association has two main features. First, the disease is focused around specific mosquito breeding sites and can normally be transmitted only within certain distances from them: in Africa these are typically between a few hundred metres and a kilometre and rarely exceed 2-3 kilometres. Second, there is a marked clustering of persons with malaria parasites and clinical symptoms at particular sites, usually households. In localities of low endemicity the level of malaria risk or case incidence may vary widely between households because the specific characteristics of houses and their locations affect contact between humans and vectors. Where endemicity is high, differences in human/vector contact rates between different households may have less effect on malaria case incidences. This is because superinfection and exposure-acquired immunity blur the proportional relationship between inoculation rates and case incidences. Accurate information on the distribution of malaria on the ground permits interventions to be targeted towards the foci of transmission and the locations and households of high malaria risk within them. Such targeting greatly increases the effectiveness of control measures. On the other hand, the inadvertent exclusion of these locations causes potentially effective control measures to fail. The computerized mapping and management of location data in geographical information systems should greatly assist the targeting of interventions against malaria at the focal and household levels, leading to improved effectiveness and cost-effectiveness of control. PMID:11196487

  7. Elimination of Plasmodium vivax Malaria in Azerbaijan

    PubMed Central

    Mammadov, Suleyman; Gasimov, Elkhan; Kurdova-Mintcheva, Rossitza; Wongsrichanalai, Chansuda

    2016-01-01

    Azerbaijan in the south caucasus region of far southeastern Europe has a long history of malaria endemicity but just successfully eliminated local transmission. After a period of relatively stable malaria situation (1960–1970), the country witnessed an epidemic followed by a series of outbreaks of various magnitudes in the following two decades, all caused by Plasmodium vivax. Compared with 1993, the number of malaria cases in the country jumped 29 times in 1994, 123 times in 1995, and 571 times in 1996 at the peak of the epidemic, when 13,135 cases were officially registered. Incidence rate increased dramatically from 0.2/100,000 population in 1991 to over 17/100,000 population in 1996. Scaled-up malaria control led to the containment of the epidemic and to a dramatic decrease of malaria burden nationwide. Azerbaijan has applied contemporary, complex control and surveillance strategies and approaches and is currently in the prevention of reintroduction phase. This article describes Azerbaijan's public health experience in conducting malaria control and elimination interventions over several decades until 2013 when the country reached an important milestone—no indigenous malaria cases were recorded. PMID:27708184

  8. Magnetic relaxometry as applied to sensitive cancer detection and localization

    SciTech Connect

    De Haro, Leyma P.; Karaulanov, Todor; Vreeland, Erika C.; Anderson, Bill; Hathaway, Helen J.; Huber, Dale L.; Matlashov, Andrei N.; Nettles, Christopher P.; Price, Andrew D.; Monson, Todd C.; Flynn, Edward R.

    2015-06-02

    Abstract

    Here we describe superparamagnetic relaxometry (SPMR), a technology that utilizes highly sensitive magnetic sensors and superparamagnetic nanoparticles for cancer detection. Using SPMR, we sensitively and specifically detect nanoparticles conjugated to biomarkers for various types of cancer. SPMR offers high contrast

    In SPMR measurements, a brief magnetizing pulse is used to align superparamagnetic nanoparticles of a discrete size. Following the pulse, an array of superconducting quantum interference detectors (SQUID) sensors detect the decaying magnetization field. NP size is chosen so that, when bound, the induced field decays in seconds. They are functionalized with specific biomarkers and incubated with cancer cells

    As a result, superparamagnetic NPs developed here have small size dispersion. Cell incubation studies measure specificity for different cell lines and antibodies with very high contrast.

  9. Magnetic relaxometry as applied to sensitive cancer detection and localization

    DOE PAGES

    De Haro, Leyma P.; Karaulanov, Todor; Vreeland, Erika C.; ...

    2015-06-02

    Here we describe superparamagnetic relaxometry (SPMR), a technology that utilizes highly sensitive magnetic sensors and superparamagnetic nanoparticles for cancer detection. Using SPMR, we sensitively and specifically detect nanoparticles conjugated to biomarkers for various types of cancer. SPMR offers high contrast In SPMR measurements, a brief magnetizing pulse is used to align superparamagnetic nanoparticles of a discrete size. Following the pulse, an array of superconducting quantum interference detectors (SQUID) sensors detect the decaying magnetization field. NP size is chosen so that, when bound, the induced field decays in seconds. They are functionalized with specific biomarkers and incubated with cancer cellsmore » As a result, superparamagnetic NPs developed here have small size dispersion. Cell incubation studies measure specificity for different cell lines and antibodies with very high contrast.« less

  10. Bead-based immunoassay allows sub-picogram detection of histidine-rich protein 2 from Plasmodium falciparum and estimates reliability of malaria rapid diagnostic tests

    PubMed Central

    Rogier, Eric; Plucinski, Mateusz; Lucchi, Naomi; Mace, Kimberly; Chang, Michelle; Lemoine, Jean Frantz; Candrinho, Baltazar; Colborn, James; Dimbu, Rafael; Fortes, Filomeno; Udhayakumar, Venkatachalam; Barnwell, John

    2017-01-01

    Detection of histidine-rich protein 2 (HRP2) from the malaria parasite Plasmodium falciparum provides evidence for active or recent infection, and is utilized for both diagnostic and surveillance purposes, but current laboratory immunoassays for HRP2 are hindered by low sensitivities and high costs. Here we present a new HRP2 immunoassay based on antigen capture through a bead-based system capable of detecting HRP2 at sub-picogram levels. The assay is highly specific and cost-effective, allowing fast processing and screening of large numbers of samples. We utilized the assay to assess results of HRP2-based rapid diagnostic tests (RDTs) in different P. falciparum transmission settings, generating estimates for true performance in the field. Through this method of external validation, HRP2 RDTs were found to perform well in the high-endemic areas of Mozambique and Angola with 86.4% and 73.9% of persons with HRP2 in their blood testing positive by RDTs, respectively, and false-positive rates of 4.3% and 0.5%. However, in the low-endemic setting of Haiti, only 14.5% of persons found to be HRP2 positive by the bead assay were RDT positive. Additionally, 62.5% of Haitians showing a positive RDT test had no detectable HRP2 by the bead assay, likely indicating that these were false positive tests. In addition to RDT validation, HRP2 biomass was assessed for the populations in these different settings, and may provide an additional metric by which to estimate P. falciparum transmission intensity and measure the impact of interventions. PMID:28192523

  11. The Toolbox for Local and Global Plagiarism Detection

    ERIC Educational Resources Information Center

    Butakov, Sergey; Scherbinin, Vladislav

    2009-01-01

    Digital plagiarism is a problem for educators all over the world. There are many software tools on the market for uncovering digital plagiarism. Most of them can work only with text submissions. In this paper, we present a new architecture for a plagiarism detection tool that can work with many different kinds of digital submissions, from plain or…

  12. Improved change detection with local co-registration adjustments

    SciTech Connect

    Wohlberg, Brendt E; Theiler, James P

    2009-01-01

    We introduce a simple approach for compensating for residual misregistration error on the performance of anomalous change detection algorithms. Using real data with a simulation framework for anomalous change and with a real anomalous change, we illustrate the approach and investigate its effectiveness.

  13. Update on Malaria Diagnostics and Test Utilization.

    PubMed

    Mathison, Blaine A; Pritt, Bobbi S

    2017-04-12

    Malaria is a potentially life-threatening disease requiring rapid diagnosis and treatment. Although microscopic examination of thick and thin blood films remains the gold standard for laboratory diagnosis, rapid antigen tests and nucleic acid amplification methods may also play a useful role for detection of acute infection. This review discusses the advantages and disadvantages of the commonly-used diagnostic methods and provides important practice points for optimal malaria test utilization.

  14. Malaria. Can WHO roll back malaria?

    PubMed

    Balter, M

    2000-10-20

    In October 1998, World Health Organization Director-General Gro Harlem Brundtland announced Roll Back Malaria, a multiagency crusade that aims to cut malaria mortality in half over the next 10 years. Brundtland might just be the one to pull it off, say numerous public health experts, although some researchers question whether the goal is realistic.

  15. Latest Progress of Fault Detection and Localization in Complex Electrical Engineering

    NASA Astrophysics Data System (ADS)

    Zhao, Zheng; Wang, Can; Zhang, Yagang; Sun, Yi

    2014-01-01

    In the researches of complex electrical engineering, efficient fault detection and localization schemes are essential to quickly detect and locate faults so that appropriate and timely corrective mitigating and maintenance actions can be taken. In this paper, under the current measurement precision of PMU, we will put forward a new type of fault detection and localization technology based on fault factor feature extraction. Lots of simulating experiments indicate that, although there are disturbances of white Gaussian stochastic noise, based on fault factor feature extraction principal, the fault detection and localization results are still accurate and reliable, which also identifies that the fault detection and localization technology has strong anti-interference ability and great redundancy.

  16. [Evaluation of epidemiological data of malaria between 2001-2011 in Sanliurfa, Turkey].

    PubMed

    Yentür Doni, Nebiye; Yıldız Zeyrek, Fadile; Seyrek, Adnan; Şimşek, Zeynep; Gürses, Gülcan; Topluoğlu, Seher

    2016-04-01

    -9 years, 10-14 years and 15 years were as follows; 2.5%, 15.1%, 18%, 13.9% and 50.5%, respectively. The detection of Plasmodium spp. in the samples examined in 2002 (1244/110.533; 1.1%) was the highest, and in 2011 (1/50.981; 0.002%) was the lowest. The distribution rates of 4394 cases according to the years between 2001 to 2011, were found as 25.4%, 28.3%, 17.8%, 10.9%, 8.9%, 5.6%, 1.4%, 1.4%, 0.2%, 0.009% and 0.02%, respectively. Of all cases, 80.6% were autochthonous and 19.4% were imported. Most of the cases were detected in Siverek county with a rate of 71.4%, followed by Ceylanpınar (13.5%) and Viranşehir (6.6%) counties. Although malaria cases were detected throughout the year in Sanliurfa in respect to the climate, the highest numbers were recorded in September (832/4394; 18.9%) and November (1054/4394; 24%). This study emphasized that malaria cases due to local transmission declined to zero in Sanliurfa like the recent situation in Turkey. However, P.falciparum malaria cases are being reported due to the travels to endemic countries or migrations from those countries. Effective malaria control attempts, within the scope of Malaria Elimination Programme implemented in Turkey, should be continued with the same stability without any abruption in Sanliurfa province where the disease had been endemic in the past.

  17. Ungulate malaria parasites

    PubMed Central

    Templeton, Thomas J.; Asada, Masahito; Jiratanh, Montakan; Ishikawa, Sohta A.; Tiawsirisup, Sonthaya; Sivakumar, Thillaiampalam; Namangala, Boniface; Takeda, Mika; Mohkaew, Kingdao; Ngamjituea, Supawan; Inoue, Noboru; Sugimoto, Chihiro; Inagaki, Yuji; Suzuki, Yasuhiko; Yokoyama, Naoaki; Kaewthamasorn, Morakot; Kaneko, Osamu

    2016-01-01

    Haemosporida parasites of even-toed ungulates are diverse and globally distributed, but since their discovery in 1913 their characterization has relied exclusively on microscopy-based descriptions. In order to bring molecular approaches to bear on the identity and evolutionary relationships of ungulate malaria parasites, we conducted Plasmodium cytb-specific nested PCR surveys using blood from water buffalo in Vietnam and Thailand, and goats in Zambia. We found that Plasmodium is readily detectable from water buffalo in these countries, indicating that buffalo Plasmodium is distributed in a wider region than India, which is the only area in which buffalo Plasmodium has been reported. Two types (I and II) of Plasmodium sequences were identified from water buffalo and a third type (III) was isolated from goat. Morphology of the parasite was confirmed in Giemsa-reagent stained blood smears for the Type I sample. Complete mitochondrial DNA sequences were isolated and used to infer a phylogeny in which ungulate malaria parasites form a monophyletic clade within the Haemosporida, and branch prior to the clade containing bird, lizard and other mammalian Plasmodium. Thus it is likely that host switching of Plasmodium from birds to mammals occurred multiple times, with a switch to ungulates independently from other mammalian Plasmodium. PMID:26996979

  18. Detection of Plasmodium vivax and Plasmodium falciparum DNA in human saliva and urine: loop-mediated isothermal amplification for malaria diagnosis.

    PubMed

    Ghayour Najafabadi, Zahra; Oormazdi, Hormozd; Akhlaghi, Lame; Meamar, Ahmad Reza; Nateghpour, Mehdi; Farivar, Leila; Razmjou, Elham

    2014-08-01

    This study investigated loop-mediated isothermal amplification (LAMP) detection of Plasmodium falciparum and Plasmodium vivax in urine and saliva of malaria patients. From May to November 2011, 108 febrile patients referred to health centers in Sistan and Baluchestan Province of south-eastern Iran participated in the study. Saliva, urine, and blood samples were analyzed with nested PCR and LAMP targeting the species-specific nucleotide sequence of small subunit ribosomal RNA gene (18S rRNA) of P. falciparum and P. vivax and evaluated for diagnostic accuracy by comparison to blood nested PCR assay. When nested PCR of blood is used as standard, microscopy and nested PCR of saliva and urine samples showed sensitivity of 97.2%, 89.4% and 71% and specificity of 100%, 97.3% and 100%, respectively. LAMP sensitivity of blood, saliva, and urine was 95.8%, 47% and 29%, respectively, whereas LAMP specificity of these samples was 100%. Microscopy and nested PCR of saliva and LAMP of blood were comparable to nested PCR of blood (к=0.95, 0.83, and 0.94, respectively), but agreement for nested PCR of urine was moderate (к=0.64) and poor to fair for saliva LAMP and urine LAMP (к=0.38 and 0.23, respectively). LAMP assay showed low sensitivity for detection of Plasmodium DNA in human saliva and urine compared to results with blood and to nested PCR of blood, saliva, and urine. However, considering the advantages of LAMP technology and of saliva and urine sampling, further research into the method is worthwhile. LAMP protocol and precise preparation protocols need to be defined and optimized for template DNA of saliva and urine.

  19. Detection of Localized Heat Damage in a Polymer Matrix Composite by Thermo-Elastic Method (Preprint)

    DTIC Science & Technology

    2007-02-01

    AFRL-ML-WP-TP-2007-437 DETECTION OF LOCALIZED HEAT DAMAGE IN A POLYMER MATRIX COMPOSITE BY THERMO-ELASTIC METHOD (PREPRINT) John Welter...GRANT NUMBER 4. TITLE AND SUBTITLE DETECTION OF LOCALIZED HEAT DAMAGE IN A POLYMER MATRIX COMPOSITE BY THERMO-ELASTIC METHOD (PREPRINT) 5c...Include Area Code) N/A Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39-18 1 DETECTION OF LOCALIZED HEAT DAMAGE IN A POLYMER MATRIX COMPOSITE BY

  20. [Diagnosis and treatment for three imported Plasmodium malariae malaria cases in Henan Province].

    PubMed

    Deng, Yan; Zhou, Rui-Min; Zhang, Hong-Wei; Qian, Dan; Liu, Ying; Chen, Wei-Qi; Zhao, Xu-Dong

    2014-02-01

    Giemsa-stained blood film microscopy, CareStart rapid detection and PCR were used to detect the three cases who returned from Angola and Equatorial Guinea to Henan Province. Onset of malaria symptoms for two patients occurred 15 d and 27 d after their return from Angola, respectively. Two months after returning home, another case relapsed who had suffered from malaria in Equatorial Guinea. All three patients had the symptoms such as irregular fever, headache, chills and so on. Two cases had elevated total bilirubin and splenomegaly. The cases were confirmed as P. malariae infection by microscopic morphological examination. Amplified bands were produced by 18S rRNA nested PCR, which was the same with P. malariae in size, whereas the results of CareStart repaid detection test were all negative. They were cured by using artemisinin-based combination therapy (ACT).

  1. Climate change unlikely to increase malaria burden in West Africa

    NASA Astrophysics Data System (ADS)

    Yamana, Teresa K.; Bomblies, Arne; Eltahir, Elfatih A. B.

    2016-11-01

    The impact of climate change on malaria transmission has been hotly debated. Recent conclusions have been drawn using relatively simple biological models and statistical approaches, with inconsistent predictions. Consequently, the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5) echoes this uncertainty, with no clear guidance for the impacts of climate change on malaria transmission, yet recognizing a strong association between local climate and malaria. Here, we present results from a decade-long study involving field observations and a sophisticated model simulating village-scale transmission. We drive the malaria model using select climate models that correctly reproduce historical West African climate, and project reduced malaria burden in a western sub-region and insignificant impact in an eastern sub-region. Projected impacts of climate change on malaria transmission in this region are not of serious concern.

  2. Congenital Malaria in Calabar, Nigeria: The Molecular Perspective

    PubMed Central

    Oduwole, Olabisi A.; Ejezie, G. C.; Odey, Friday A.; Oringanje, Chioma M.; Nwakanma, Davis; Bello, Segun; Oriero, Eniyou; Okebe, Joseph; Alaribe, Anyawu A.; Etuk, Saturday; Meremikwu, Martin

    2011-01-01

    Polymerase chain reaction (PCR) has been shown to be more sensitive in detecting low-level parasitemia than conventional blood film microscopy. We estimated the prevalence of congenital malaria using nested PCR amplification of the small subunit 18S RNA gene to detect low-level parasitemia and identify Plasmodium species in 204 mother–neonate pairs. Cord-blood parasitemia was detected in four babies by PCR, giving a prevalence of 2.0%. The newborns of primidgravidae were more susceptible to congenital malaria than those of multigravidae (P < 0.0001). There was a strong correlation between placental malaria and congenital malaria (odds ratio = 10.1, 95% confidence interval = 1.3–76.1, P = 0.0487). We conclude that the prevalence of congenital malaria in Calabar detected by PCR is lower than has been reported in this environment through microscopy. PMID:21363974

  3. The Malaria Transition on the Arabian Peninsula: Progress toward a Malaria-Free Region between 1960–2010

    PubMed Central

    Snow, Robert W.; Amratia, Punam; Zamani, Ghasem; Mundia, Clara W.; Noor, Abdisalan M.; Memish, Ziad A.; Al Zahrani, Mohammad H.; Al Jasari, Adel; Fikri, Mahmoud; Atta, Hoda

    2014-01-01

    The transmission of malaria across the Arabian Peninsula is governed by the diversity of dominant vectors and extreme aridity. It is likely that where malaria transmission was historically possible it was intense and led to a high disease burden. Here, we review the speed of elimination, approaches taken, define the shrinking map of risk since 1960 and discuss the threats posed to a malaria-free Arabian Peninsula using the archive material, case data and published works. From as early as the 1940s, attempts were made to eliminate malaria on the peninsula but were met with varying degrees of success through to the 1970s; however, these did result in a shrinking of the margins of malaria transmission across the peninsula. Epidemics in the 1990s galvanised national malaria control programmes to reinvigorate control efforts. Before the launch of the recent global ambition for malaria eradication, countries on the Arabian Peninsula launched a collaborative malaria-free initiative in 2005. This initiative led a further shrinking of the malaria risk map and today locally acquired clinical cases of malaria are reported only in Saudi Arabia and Yemen, with the latter contributing to over 98% of the clinical burden. PMID:23548086

  4. Uncertainty in Mapping Malaria Epidemiology: Implications for Control

    PubMed Central

    Sullivan, David

    2010-01-01

    Malaria is a location-specific, dynamic infectious disease transmitted by mosquitoes to humans and is influenced by environmental, vector, parasite, and host factors. The principal purposes of malarial epidemiology are 1) to describe the malarial distribution in space and time along with the physical, biologic, and social etiologic factors and 2) to guide control objectives for either modeling impact or measuring progress of control tactics. Mapping malaria and many of its causative factors has been achieved on many different levels from global distribution to biologic quantitative trait localization in humans, parasites, and mosquitoes. Despite these important achievements, a large degree of uncertainty still exists on the annual burden of malarial cases. Accurate, sensitive detection and treatment of asymptomatic reservoirs important to infectious transmission are additional components necessary for future control measures. Presently spurred by the leadership and funding of Bill and Melinda Gates, the malarial community is developing and implementing plans for elimination of malaria. The challenge for malariologists is to digitally integrate and map epidemiologic factors and intervention measures in space and time to target effective, sustainable control alongside research efforts. PMID:20581219

  5. RESUME OF METHODS FOR CONTROL OF MALARIA: INDICATIONS; RESULTS; COSTS

    PubMed Central

    Carter, H. R.

    1920-01-01

    Eighty to ninety-nine per cent reduction in physicians' calls to malaria patients has been the result of malaria control work in the South. The author notes that there is no set rule for all localities. Cost is a factor not to be ignored. Quinine is sometimes necessary, but usually mosquito control is adopted. PMID:18010329

  6. Localization of tumors in various organs, using edge detection algorithms

    NASA Astrophysics Data System (ADS)

    López Vélez, Felipe

    2015-09-01

    The edge of an image is a set of points organized in a curved line, where in each of these points the brightness of the image changes abruptly, or has discontinuities, in order to find these edges there will be five different mathematical methods to be used and later on compared with its peers, this is with the aim of finding which of the methods is the one that can find the edges of any given image. In this paper these five methods will be used for medical purposes in order to find which one is capable of finding the edges of a scanned image more accurately than the others. The problem consists in analyzing the following two biomedicals images. One of them represents a brain tumor and the other one a liver tumor. These images will be analyzed with the help of the five methods described and the results will be compared in order to determine the best method to be used. It was decided to use different algorithms of edge detection in order to obtain the results shown below; Bessel algorithm, Morse algorithm, Hermite algorithm, Weibull algorithm and Sobel algorithm. After analyzing the appliance of each of the methods to both images it's impossible to determine the most accurate method for tumor detection due to the fact that in each case the best method changed, i.e., for the brain tumor image it can be noticed that the Morse method was the best at finding the edges of the image but for the liver tumor image it was the Hermite method. Making further observations it is found that Hermite and Morse have for these two cases the lowest standard deviations, concluding that these two are the most accurate method to find the edges in analysis of biomedical images.

  7. Targeting Human Transmission Biology for Malaria Elimination

    PubMed Central

    Buckee, Caroline; Marti, Matthias

    2015-01-01

    Malaria remains one of the leading causes of death worldwide, despite decades of public health efforts. The recent commitment by many endemic countries to eliminate malaria marks a shift away from programs aimed at controlling disease burden towards one that emphasizes reducing transmission of the most virulent human malaria parasite, Plasmodium falciparum. Gametocytes, the only developmental stage of malaria parasites able to infect mosquitoes, have remained understudied, as they occur in low numbers, do not cause disease, and are difficult to detect in vivo by conventional methods. Here, we review the transmission biology of P. falciparum gametocytes, featuring important recent discoveries of genes affecting parasite commitment to gametocyte formation, microvesicles enabling parasites to communicate with each other, and the anatomical site where immature gametocytes develop. We propose potential parasite targets for future intervention and highlight remaining knowledge gaps. PMID:26086192

  8. Novel detection of local tooth damage in gears by the wavelet bicoherence

    NASA Astrophysics Data System (ADS)

    Combet, F.; Gelman, L.; LaPayne, G.

    2012-01-01

    A new technique, the instantaneous wavelet bicoherence (WB) is proposed and investigated. The use of the instantaneous and locally averaged WB from vibration measurements for local damage detection in gears is investigated for the first time; these bicoherences are better adapted than the classical Fourier bicoherence to the case of non-stationary signals. A new diagnostic feature based on the integrated modulus of the WB in a specific frequency range and a methodology for feature estimation are proposed. The WB techniques are applied to detection of a multiple "like natural" pitting on a back-to-back industrial spur gearbox system and natural pitting on a gear at test rig and show the possibility of early detection of local tooth faults. The detection effectiveness is evaluated by a local Fisher criterion estimated at each angular position of gear for the unpitted and pitted cases. The proposed WB-based diagnostic feature demonstrates robust experimental performance and superior detection capabilities (i.e., effective early damage detection differentially for teeth of the gear wheel) over the conventional detection methods based on the wavelet transform. The reason for this superior effectiveness is that the WB exploits the phase couplings of the wavelet transform at different frequencies, which contain useful additional information for detection of non-linear phenomena induced by local faults. The proposed approaches are compared with the two conventional approaches based on the wavelet transform.

  9. Changes in the burden of malaria following scale up of malaria control interventions in Mutasa District, Zimbabwe

    PubMed Central

    2013-01-01

    Background To better understand trends in the burden of malaria and their temporal relationship to control activities, a survey was conducted to assess reported cases of malaria and malaria control activities in Mutasa District, Zimbabwe. Methods Data on reported malaria cases were abstracted from available records at all three district hospitals, three rural hospitals and 25 rural health clinics in Mutasa District from 2003 to 2011. Results Malaria control interventions were scaled up through the support of the Roll Back Malaria Partnership, the Global Fund to Fight AIDS, Tuberculosis and Malaria, and The President’s Malaria Initiative. The recommended first-line treatment regimen changed from chloroquine or a combination of chloroquine plus sulphadoxine/pyrimethamine to artemisinin-based combination therapy, the latter adopted by 70%, 95% and 100% of health clinics by 2008, 2009 and 2010, respectively. Diagnostic capacity improved, with rapid diagnostic tests (RDTs) available in all health clinics by 2008. Vector control consisted of indoor residual spraying and distribution of long-lasting insecticidal nets. The number of reported malaria cases initially increased from levels in 2003 to a peak in 2008 but then declined 39% from 2008 to 2010. The proportion of suspected cases of malaria in older children and adults remained high, ranging from 75% to 80%. From 2008 to 2010, the number of RDT positive cases of malaria decreased 35% but the decrease was greater for children younger than five years of age (60%) compared to older children and adults (26%). Conclusions The burden of malaria in Mutasa District decreased following the scale up of malaria control interventions. However, the persistent high number of cases in older children and adults highlights the need for strategies to identify locally effective control measures that target all age groups. PMID:23815862

  10. Impact of Malaria in Pregnancy as Latin America Approaches Elimination.

    PubMed

    Yanow, Stephanie K; Gavina, Kenneth; Gnidehou, Sedami; Maestre, Amanda

    2016-05-01

    In Latin America, four million pregnancies are at risk of malaria annually, but malaria in pregnancy is largely overlooked. As countries progress toward malaria elimination, targeting reservoirs of transmission is a priority. Pregnant women are an important risk group because they harbor asymptomatic infections and dormant liver stages of Plasmodium vivax that cause relapses. Of significant concern is the discovery that most infections in pregnant women fail to be detected by routine diagnostics. We review here recent findings on malaria in pregnancy within Latin America. We focus on the Amazon basin and Northwest Colombia, areas that harbor the greatest burden of malaria, and propose that more sensitive diagnostics and active surveillance at antenatal clinics will be necessary to eliminate malaria from these final frontiers.

  11. Towards malaria risk prediction in Afghanistan using remote sensing

    PubMed Central

    2010-01-01

    Background Malaria is a significant public health concern in Afghanistan. Currently, approximately 60% of the population, or nearly 14 million people, live in a malaria-endemic area. Afghanistan's diverse landscape and terrain contributes to the heterogeneous malaria prevalence across the country. Understanding the role of environmental variables on malaria transmission can further the effort for malaria control programme. Methods Provincial malaria epidemiological data (2004-2007) collected by the health posts in 23 provinces were used in conjunction with space-borne observations from NASA satellites. Specifically, the environmental variables, including precipitation, temperature and vegetation index measured by the Tropical Rainfall Measuring Mission and the Moderate Resolution Imaging Spectoradiometer, were used. Regression techniques were employed to model malaria cases as a function of environmental predictors. The resulting model was used for predicting malaria risks in Afghanistan. The entire time series except the last 6 months is used for training, and the last 6-month data is used for prediction and validation. Results Vegetation index, in general, is the strongest predictor, reflecting the fact that irrigation is the main factor that promotes malaria transmission in Afghanistan. Surface temperature is the second strongest predictor. Precipitation is not shown as a significant predictor, as it may not directly lead to higher larval population. Autoregressiveness of the malaria epidemiological data is apparent from the analysis. The malaria time series are modelled well, with provincial average R2 of 0.845. Although the R2 for prediction has larger variation, the total 6-month cases prediction is only 8.9% higher than the actual cases. Conclusions The provincial monthly malaria cases can be modelled and predicted using satellite-measured environmental parameters with reasonable accuracy. The Third Strategic Approach of the WHO EMRO Malaria Control and

  12. Community mobilization for malaria elimination: application of an open space methodology in Ruhuha sector, Rwanda

    PubMed Central

    2014-01-01

    Background Despite the significant reduction of malaria transmission in Rwanda, Ruhuha sector is still a highly endemic area for malaria. The objective of this activity was to explore and brainstorm the potential roles of various community stakeholders in malaria elimination. Methods Horizontal participatory approaches such as ‘open space’ have been deployed to explore local priorities, stimulate community contribution to project planning, and to promote local capacity to manage programmes. Two open space meetings were conducted with 62 and 82 participants in years 1 and 2, respectively. Participants included purposively selected community and local organizations’ representatives. Results Malaria was perceived as a health concern by the respondents despite the reported reduction in prevalence from 60 to 20% for cases at the local health centre. Some misconceptions of the cause of malaria and misuse of preventive strategies were noted. Poverty was deemed to be a contributing factor to malaria transmission, with suggestions that improvement of living conditions for poor families might help malaria reduction. Participants expressed willingness to contribute to malaria elimination and underscored the need for constant education, sensitization and mobilization towards malaria control in general. Active diagnosis, preventative strategies and prompt treatment of malaria cases were all mentioned by participants as ways to reduce malaria. Participants suggested that partnership of stakeholders at various levels could speed up programme activities. A community rewards system was deemed important to motivate engaged participants, i.e., community health workers and households. Establishment of malaria clubs in schools settings was also suggested as crucial to speed up community awareness and increase skills towards further malaria reduction. Conclusions This bottom-up approach was found useful in engaging the local community, enabling them to explore issues related to

  13. Psychosomatics of malaria.

    PubMed

    Houghton, D L

    1980-03-01

    Cerebral malaria with psychosomatic manifestations is one aspect of malaria which may be mistaken for mental illness. However, the psychosomatic aspects of the disease also relate to the biological, psychological and social influences which may determine changes in disease incidence and distribution. The history of the Global Malaria Eradication Campaign and the resurgence of malaria in many countries of the world have influenced attitudes and the professional milieu in which present day malaria control programmes seek to operate. The individual in a malarious area may obstruct malaria control operations by refusing to allow indoor spraying or to take prophylactic medication. Cultural beliefs often described the history of malaria in a community and the way in which the community had come to terms with this disease. Socio-economic development and population movement may disturb this equilibrium and result in a rise in malaria incidence. Behavioural habits may increase malaria risk and the degree to which the community is prepared to become involved in malaria control may influence its experience with the disease.

  14. Detecting Breakdowns in Local Coherence in the Writing of Chinese English Learners

    ERIC Educational Resources Information Center

    Wang, Y.; Harrington, M.; White, P.

    2012-01-01

    This paper introduces "CTutor", an automated writing evaluation (AWE) tool for detecting breakdowns in local coherence and reports on a study that applies it to the writing of Chinese L2 English learners. The program is based on Centering theory (CT), a theory of local coherence and salience. The principles of CT are first introduced and…

  15. [Malaria and intestinal protozoa].

    PubMed

    Rojo-Marcos, Gerardo; Cuadros-González, Juan

    2016-03-01

    Malaria is life threatening and requires urgent diagnosis and treatment. Incidence and mortality are being reduced in endemic areas. Clinical features are unspecific so in imported cases it is vital the history of staying in a malarious area. The first line treatments for Plasmodium falciparum are artemisinin combination therapies, chloroquine in most non-falciparum and intravenous artesunate if any severity criteria. Human infections with intestinal protozoa are distributed worldwide with a high global morbid-mortality. They cause diarrhea and sometimes invasive disease, although most are asymptomatic. In our environment populations at higher risk are children, including adopted abroad, immune-suppressed, travelers, immigrants, people in contact with animals or who engage in oral-anal sex. Diagnostic microscopic examination has low sensitivity improving with antigen detection or molecular methods. Antiparasitic resistances are emerging lately.

  16. Multifocal autochthonous transmission of malaria--Florida, 2003.

    PubMed

    2004-05-21

    The majority of malaria cases diagnosed in the United States are imported, usually by persons traveling from areas where malaria is endemic. However, small outbreaks of locally acquired mosquito-borne malaria continue to occur. During July-September 2003, an outbreak of malaria (eight cases of Plasmodium vivax malaria) occurred in Palm Beach County, Florida. During the same period, two patients were evaluated for malaria in neighboring Okeechobee County, approximately 75 miles from the Palm Beach County transmission area. One patient was thought to have acquired infection with the same parasite species (P. vivax), and concerns were raised about a possible link. To determine whether infection was acquired in Okeechobee County and whether a possible link existed to the Palm Beach County outbreak, the Florida Department of Health (FDOH) initiated an investigation. This report describes that investigation, which determined that although initial laboratory results suggested local transmission, subsequent evaluation and testing confirmed the case as imported malaria. These findings underscore the importance of a rapid and thorough investigation of any malaria case suspected to be acquired through local mosquito-borne transmission.

  17. Malaria Imported from Ghana by Returning Gold Miners, China, 2013

    PubMed Central

    Li, Zhongjie; Yang, Yichao; Xiao, Ning; Zhou, Sheng; Lin, Kangming; Wang, Duoquan; Zhang, Qian; Jiang, Weikang; Li, Mei; Feng, Xinyu; Yu, Jianxin; Ren, Xiang; Lai, Shengjie; Sun, Junling; Fang, Zhongliao; Hu, Wenbiao; Clements, Archie C.A.; Zhou, Xiaonong

    2015-01-01

    During May-August 2013, a malaria outbreak comprising 874 persons in Shanglin County, China, was detected among 4,052 persons returning from overseas. Ghana was the predominant destination country, and 92.3% of malarial infections occurred in gold miners. Preventive measures should be enhanced for persons in high-risk occupations traveling to malaria-endemic countries. PMID:25897805

  18. Malaria Prevalence, Spatial Clustering and Risk Factors in a Low Endemic Area of Eastern Rwanda: A Cross Sectional Study

    PubMed Central

    Bizimana, Jean Pierre; Agaba, Steven; Dukuzumuremyi, Javier; Baas, Lisette; de Dieu Harelimana, Jean; Mens, Petra F.; Boer, Kimberly R.; de Vries, Peter J.

    2013-01-01

    Background Rwanda reported significant reductions in malaria burden following scale up of control intervention from 2005 to 2010. This study sought to; measure malaria prevalence, describe spatial malaria clustering and investigate for malaria risk factors among health-centre-presumed malaria cases and their household members in Eastern Rwanda. Methods A two-stage health centre and household-based survey was conducted in Ruhuha sector, Eastern Rwanda from April to October 2011. At the health centre, data, including malaria diagnosis and individual level malaria risk factors, was collected. At households of these Index cases, a follow-up survey, including malaria screening for all household members and collecting household level malaria risk factor data, was conducted. Results Malaria prevalence among health centre attendees was 22.8%. At the household level, 90 households (out of 520) had at least one malaria-infected member and the overall malaria prevalence for the 2634 household members screened was 5.1%. Among health centre attendees, the age group 5–15 years was significantly associated with an increased malaria risk and a reported ownership of ≥4 bednets was significantly associated with a reduced malaria risk. At the household level, age groups 5–15 and >15 years and being associated with a malaria positive index case were associated with an increased malaria risk, while an observed ownership of ≥4 bednets was associated with a malaria risk-protective effect. Significant spatial malaria clustering among household cases with clusters located close to water- based agro-ecosystems was observed. Conclusions Malaria prevalence was significantly higher among health centre attendees and their household members in an area with significant household spatial malaria clustering. Circle surveillance involving passive case finding at health centres and proactive case detection in households can be a powerful tool for identifying household level malaria burden

  19. Attractive toxic sugar bait (ATSB) methods decimate populations of Anopheles malaria vectors in arid environments regardless of the local availability of favoured sugar-source blossoms

    PubMed Central

    2012-01-01

    Background Attractive toxic sugar bait (ATSB) methods are a new and promising "attract and kill" strategy for mosquito control. Sugar-feeding female and male mosquitoes attracted to ATSB solutions, either sprayed on plants or in bait stations, ingest an incorporated low-risk toxin such as boric acid and are killed. This field study in the arid malaria-free oasis environment of Israel compares how the availability of a primary natural sugar source for Anopheles sergentii mosquitoes: flowering Acacia raddiana trees, affects the efficacy of ATSB methods for mosquito control. Methods A 47-day field trial was conducted to compare impacts of a single application of ATSB treatment on mosquito densities and age structure in isolated uninhabited sugar-rich and sugar-poor oases relative to an untreated sugar-rich oasis that served as a control. Results ATSB spraying on patches of non-flowering vegetation around freshwater springs reduced densities of female An. sergentii by 95.2% in the sugar-rich oasis and 98.6% in the sugar-poor oasis; males in both oases were practically eliminated. It reduced daily survival rates of female An. sergentii from 0.77 to 0.35 in the sugar-poor oasis and from 0.85 to 0.51 in the sugar-rich oasis. ATSB treatment reduced the proportion of older more epidemiologically dangerous mosquitoes (three or more gonotrophic cycles) by 100% and 96.7%, respectively, in the sugar-poor and sugar-rich oases. Overall, malaria vectorial capacity was reduced from 11.2 to 0.0 in the sugar-poor oasis and from 79.0 to 0.03 in the sugar-rich oasis. Reduction in vector capacity to negligible levels days after ATSB application in the sugar-poor oasis, but not until after 2 weeks in the sugar-rich oasis, show that natural sugar sources compete with the applied ATSB solutions. Conclusion While readily available natural sugar sources delay ATSB impact, they do not affect overall outcomes because the high frequency of sugar feeding by mosquitoes has an accumulating effect

  20. Global malaria connectivity through air travel

    PubMed Central

    2013-01-01

    Background Air travel has expanded at an unprecedented rate and continues to do so. Its effects have been seen on malaria in rates of imported cases, local outbreaks in non-endemic areas and the global spread of drug resistance. With elimination and global eradication back on the agenda, changing levels and compositions of imported malaria in malaria-free countries, and the threat of artemisinin resistance spreading from Southeast Asia, there is a need to better understand how the modern flow of air passengers connects each Plasmodium falciparum- and Plasmodium vivax-endemic region to the rest of the world. Methods Recently constructed global P. falciparum and P.vivax malaria risk maps, along with data on flight schedules and modelled passenger flows across the air network, were combined to describe and quantify global malaria connectivity through air travel. Network analysis approaches were then utilized to describe and quantify the patterns that exist in passenger flows weighted by malaria prevalence. Finally, the connectivity within and to the Southeast Asia region where the threat of imported artemisinin resistance arising is highest, was examined to highlight risk routes for its spread. Results The analyses demonstrate the substantial connectivity that now exists between and from malaria-endemic regions through air travel. While the air network provides connections to previously isolated malarious regions, it is clear that great variations exist, with significant regional communities of airports connected by higher rates of flow standing out. The structures of these communities are often not geographically coherent, with historical, economic and cultural ties evident, and variations between P. falciparum and P. vivax clear. Moreover, results highlight how well connected the malaria-endemic areas of Africa are now to Southeast Asia, illustrating the many possible routes that artemisinin-resistant strains could take. Discussion The continuing growth in air

  1. Malaria resurgence in India: a critical study.

    PubMed

    Sharma, V P; Mehrotra, K N

    1986-01-01

    In 1953, the Indian National Malaria Control Programme (NMCP) was started. Encouraged by the results, and the fact that insecticide resistance in vector species may evolve and become an obstacle, in 1958 a control programme was converted to the National Malaria Eradication Programme (NMEP). By 1964, malaria was eradicated from 88% of the area and it was in the advanced stage of spraying in the remaining parts. At that time, focal outbreaks that occurred in 1965 and increased in later years, could not be contained due to the shortages of DDT. As a result, large areas in consolidation and maintenance phases were reverted to the attack phase. Besides, the infrastructure in general health services was not adequate and mature enough to take up surveillance and vigilance. This produced a large number of secondary cases due to the re-introduction and relapse of malaria. Added to this was the problem of urban malaria, the control of which was the responsibility of local bodies. Malaria cases increased in towns, and started diffusing to the rural areas, due to inadequate staff and the shortages of malarial larvicidal oil (MLO). Later, it turned out, that while it was technically feasible to eradicate malaria from 91% of the population, the strategy of indoor spraying of DDT to interrupt transmission did not succeed in 9.0% of the population, despite more than 12-14 years of regular spraying. During the years of resurgence, there was no research support to the programme, so that technical problems were not properly appreciated, understood and tackled. The reservoir of parasites that were present throughout the country started multiplying and spreading to newer areas due to the presence of vectors in high densities. Thus malaria resurged and re-established itself even in areas that were at one time freed from the disease. The analysis of the pattern of malaria resurgence revealed that malaria outbreaks preceded the true problem of insecticide resistance. It is noteworthy to

  2. Spatial synchrony of malaria outbreaks in a highland region of Ethiopia.

    PubMed

    Wimberly, Michael C; Midekisa, Alemayehu; Semuniguse, Paulos; Teka, Hiwot; Henebry, Geoffrey M; Chuang, Ting-Wu; Senay, Gabriel B

    2012-10-01

    To understand the drivers and consequences of malaria in epidemic-prone regions, it is important to know whether epidemics emerge independently in different areas as a consequence of local contingencies, or whether they are synchronised across larger regions as a result of climatic fluctuations and other broad-scale drivers. To address this question, we collected historical malaria surveillance data for the Amhara region of Ethiopia and analysed them to assess the consistency of various indicators of malaria risk and determine the dominant spatial and temporal patterns of malaria within the region. We collected data from a total of 49 districts from 1999-2010. Data availability was better for more recent years and more data were available for clinically diagnosed outpatient malaria cases than confirmed malaria cases. Temporal patterns of outpatient malaria case counts were correlated with the proportion of outpatients diagnosed with malaria and confirmed malaria case counts. The proportion of outpatients diagnosed with malaria was spatially clustered, and these cluster locations were generally consistent from year to year. Outpatient malaria cases exhibited spatial synchrony at distances up to 300 km, supporting the hypothesis that regional climatic variability is an important driver of epidemics. Our results suggest that decomposing malaria risk into separate spatial and temporal components may be an effective strategy for modelling and forecasting malaria risk across large areas. They also emphasise both the value and limitations of working with historical surveillance datasets and highlight the importance of enhancing existing surveillance efforts.

  3. Biodiversity Can Help Prevent Malaria Outbreaks in Tropical Forests

    PubMed Central

    Laporta, Gabriel Zorello; de Prado, Paulo Inácio Knegt Lopez; Kraenkel, Roberto André; Coutinho, Renato Mendes; Sallum, Maria Anice Mureb

    2013-01-01

    Background Plasmodium vivax is a widely distributed, neglected parasite that can cause malaria and death in tropical areas. It is associated with an estimated 80–300 million cases of malaria worldwide. Brazilian tropical rain forests encompass host- and vector-rich communities, in which two hypothetical mechanisms could play a role in the dynamics of malaria transmission. The first mechanism is the dilution effect caused by presence of wild warm-blooded animals, which can act as dead-end hosts to Plasmodium parasites. The second is diffuse mosquito vector competition, in which vector and non-vector mosquito species compete for blood feeding upon a defensive host. Considering that the World Health Organization Malaria Eradication Research Agenda calls for novel strategies to eliminate malaria transmission locally, we used mathematical modeling to assess those two mechanisms in a pristine tropical rain forest, where the primary vector is present but malaria is absent. Methodology/Principal Findings The Ross–Macdonald model and a biodiversity-oriented model were parameterized using newly collected data and data from the literature. The basic reproduction number () estimated employing Ross–Macdonald model indicated that malaria cases occur in the study location. However, no malaria cases have been reported since 1980. In contrast, the biodiversity-oriented model corroborated the absence of malaria transmission. In addition, the diffuse competition mechanism was negatively correlated with the risk of malaria transmission, which suggests a protective effect provided by the forest ecosystem. There is a non-linear, unimodal correlation between the mechanism of dead-end transmission of parasites and the risk of malaria transmission, suggesting a protective effect only under certain circumstances (e.g., a high abundance of wild warm-blooded animals). Conclusions/Significance To achieve biological conservation and to eliminate Plasmodium parasites in human populations

  4. Vaccines Against Malaria

    PubMed Central

    Ouattara, Amed; Laurens, Matthew B.

    2015-01-01

    Despite global efforts to control malaria, the illness remains a significant public health threat. Currently, there is no licensed vaccine against malaria, but an efficacious vaccine would represent an important public health tool for successful malaria elimination. Malaria vaccine development continues to be hindered by a poor understanding of antimalarial immunity, a lack of an immune correlate of protection, and the genetic diversity of malaria parasites. Current vaccine development efforts largely target Plasmodium falciparum parasites in the pre-erythrocytic and erythrocytic stages, with some research on transmission-blocking vaccines against asexual stages and vaccines against pregnancy-associated malaria. The leading pre-erythrocytic vaccine candidate is RTS,S, and early results of ongoing Phase 3 testing show overall efficacy of 46% against clinical malaria. The next steps for malaria vaccine development will focus on the design of a product that is efficacious against the highly diverse strains of malaria and the identification of a correlate of protection against disease. PMID:25452593

  5. Risk Assessment of Malaria Prevalence in Ludian, Yongshan, and Jinggu Counties, Yunnan Province, after 2014 Earthquake Disaster

    PubMed Central

    Feng, Jun; Xia, Zhigui; Zhang, Li; Cheng, Siyuan; Wang, Rubo

    2016-01-01

    The objective of this study was to investigate malaria prevalence after the 2014 earthquakes in Ludian, Yongshan, and Jinggu counties, Yunnan Province, China. We collected and analyzed epidemiological data and made a risk assessment of transmission probability. From January 2005 to July 2015, 87 malaria cases were reported in the three counties, most of which (81.6%) occurred between 2005 and 2009, with five cases reported in Jinggu County between January 2014 and July 2015, of which one case was reported after the earthquake. In addition, no local transmission occurred in the three counties from 2010, and 95.5% of imported malaria occurred in patients who had returned from Myanmar. The townships of Lehong, Qingsheng, and Weiyuan were the main endemic areas in the three counties. The probability of malaria transmission in the three counties was low, but Jinggu County had a higher risk due to the existence of infected patients and an appropriate vector. With sporadic cases reported annually, close monitoring should continue to enhance early detection of a possible malaria outbreak. PMID:26711514

  6. Aperture optimization in emission imaging using ideal observers for joint detection and localization

    NASA Astrophysics Data System (ADS)

    Zhou, Lili; Khurd, Parmeshwar; Kulkarni, Santosh; Rangarajan, Anand; Gindi, Gene

    2008-04-01

    For the familiar 2-class detection problem (signal present/absent), ideal observers have been applied to optimization of pinhole and collimator parameters in planar emission imaging. Given photon noise and background and signal variabilities, such experiments show how to optimize an aperture to maximize detectability of the signal. Here, we consider a fundamentally different, more realistic task in which the observer is required to both detect and localize a signal. The signal is embedded in a variable background and is known except for location. We inquire whether the addition of a localization requirement changes conclusions on aperture optimization. We have previously formulated an ideal observer for this joint detection/localization task, and here apply it to the classic problem of determining an optimal pinhole diameter in a planar emission imaging system. We conclude that as search tolerance on localization decreases, the optimal pinhole diameter shrinks from that required by detection alone, and, in addition, task performance becomes more sensitive to fluctuations about the optimal pinhole diameter. As in the case for detection only, the optimal pinhole diameter shrinks as the amount of background variability grows and, in addition, conspicuity limits can be observed. Unlike the case for detection only, our task leads to a finite aperture size in the absence of background variability. For both tasks, the inclusion of background variability yields a finite aperture size.

  7. Remotely Sensed Environmental Conditions and Malaria Mortality in Three Malaria Endemic Regions in Western Kenya

    PubMed Central

    Ahlm, Clas; Rocklöv, Joacim

    2016-01-01

    Background Malaria is an important cause of morbidity and mortality in malaria endemic countries. The malaria mosquito vectors depend on environmental conditions, such as temperature and rainfall, for reproduction and survival. To investigate the potential for weather driven early warning systems to prevent disease occurrence, the disease relationship to weather conditions need to be carefully investigated. Where meteorological observations are scarce, satellite derived products provide new opportunities to study the disease patterns depending on remotely sensed variables. In this study, we explored the lagged association of Normalized Difference Vegetation Index (NVDI), day Land Surface Temperature (LST) and precipitation on malaria mortality in three areas in Western Kenya. Methodology and Findings The lagged effect of each environmental variable on weekly malaria mortality was modeled using a Distributed Lag Non Linear Modeling approach. For each variable we constructed a natural spline basis with 3 degrees of freedom for both the lag dimension and the variable. Lag periods up to 12 weeks were considered. The effect of day LST varied between the areas with longer lags. In all the three areas, malaria mortality was associated with precipitation. The risk increased with increasing weekly total precipitation above 20 mm and peaking at 80 mm. The NDVI threshold for increased mortality risk was between 0.3 and 0.4 at shorter lags. Conclusion This study identified lag patterns and association of remote- sensing environmental factors and malaria mortality in three malaria endemic regions in Western Kenya. Our results show that rainfall has the most consistent predictive pattern to malaria transmission in the endemic study area. Results highlight a potential for development of locally based early warning forecasts that could potentially reduce the disease burden by enabling timely control actions. PMID:27115874

  8. Arboviral diseases and malaria in Australia, 2009-10: annual report of the National Arbovirus and Malaria Advisory Committee.

    PubMed

    Wright, Phil; Fitzsimmons, Gerard J; Johansen, Cheryl A; Whelan, Peter I

    2012-03-31

    The National Notifiable Diseases Surveillance System received 7,609 notified cases of disease transmitted by mosquitoes for the season 1 July 2009 to 30 June 2010. The alphaviruses Barmah Forest virus and Ross River virus, accounted for 6,546 (79%) of these notifications during the 2009-10 season. There were 37 notifications of dengue virus infection locally-acquired from North Queensland and 581 notified cases in Australia that resulted from overseas travel. This number of overseas acquired cases continues to rise each year due to increasing disease activity in the Asia-Pacific region and increased air travel. Detection of flavivirus seroconversions in sentinel chicken flocks across Australia provides an early warning of increased levels of Murray Valley encephalitis virus and Kunjin virus activity. Flavivirus activity was detected in western and northern Australia in 2009-10, which prompted public health action. No human cases of Murray Valley encephalitis virus infection were notified, while there were 2 cases of Kunjin virus infection notified. There were no notifications of locally-acquired malaria in Australia and 429 notifications of overseas-acquired malaria during the 2009-10 season. This annual report presents information of diseases transmitted by mosquitoes in Australia and notified to the National Notifiable Diseases Surveillance System.

  9. Clinical algorithm for malaria during low and high transmission seasons

    PubMed Central

    Muhe, L.; Oljira, B.; Degefu, H.; Enquesellassie, F.; Weber, M.

    1999-01-01

    OBJECTIVES—To assess the proportion of children with febrile disease who suffer from malaria and to identify clinical signs and symptoms that predict malaria during low and high transmission seasons.
STUDY DESIGN—2490 children aged 2 to 59 months presenting to a health centre in rural Ethiopia with fever had their history documented and the following investigations: clinical examination, diagnosis, haemoglobin measurement, and a blood smear for malaria parasites. Clinical findings were related to the presence of malaria parasitaemia.
RESULTS—Malaria contributed to 5.9% of all febrile cases from January to April and to 30.3% during the rest of the year. Prediction of malaria was improved by simple combinations of a few signs and symptoms. Fever with a history of previous malarial attack or absence of cough or a finding of pallor gave a sensitivity of 83% in the high risk season and 75% in the low risk season, with corresponding specificities of 51% and 60%; fever with a previous malaria attack or pallor or splenomegaly had sensitivities of 80% and 69% and specificities of 65% and 81% in high and low risk settings, respectively.
CONCLUSION—Better clinical definitions are possible for low malaria settings when microscopic examination cannot be done. Health workers should be trained to detect pallor and splenomegaly because these two signs improve the specificity for malaria.

 PMID:10451393

  10. Locally Estimated Hemodynamic Response Function and Activation Detection Sensitivity in Heroin-Cue Reactivity Study

    PubMed Central

    Maleki-Balajoo, Somayeh; Hossein-Zadeh, Gholam-Ali; Soltanian-Zadeh, Hamid; Ekhtiari, Hamed

    2016-01-01

    Introduction: A fixed hemodynamic response function (HRF) is commonly used for functional magnetic resonance imaging (fMRI) analysis. However, HRF may vary from region to region and subject to subject. We investigated the effect of locally estimated HRF (in functionally homogenous parcels) on activation detection sensitivity in a heroin cue reactivity study. Methods: We proposed a novel exploratory method for brain parcellation based on a probabilistic model to segregate the brain into spatially connected and functionally homogeneous components. Then, we estimated HRF and detected activated regions in response to an experimental task in each parcel using a joint detection estimation (JDE) method. We compared the proposed JDE method with the general linear model (GLM) that uses a fixed HRF and is implemented in FEAT (as a part of FMRIB Software Library, version 4.1). Results: 1) Regions detected by JDE are larger than those detected by fixed HRF, 2) In group analysis, JDE found areas of activation not detected by fixed HRF. It detected drug craving a priori “regions-of-interest” in the limbic lobe (anterior cingulate cortex [ACC], posterior cingulate cortex [PCC] and cingulate gyrus), basal ganglia, especially striatum (putamen and head of caudate), and cerebellum in addition to the areas detected by the fixed HRF method, 3) JDE obtained higher Z-values of local maxima compared to those obtained by fixed HRF. Conclusion: In our study of heroin cue reactivity, our proposed method (that estimates HRF locally) outperformed the conventional GLM that uses a fixed HRF. PMID:27872691

  11. An algorithm for automated detection, localization and measurement of local calcium signals from camera-based imaging.

    PubMed

    Ellefsen, Kyle L; Settle, Brett; Parker, Ian; Smith, Ian F

    2014-09-01

    Local Ca(2+) transients such as puffs and sparks form the building blocks of cellular Ca(2+) signaling in numerous cell types. They have traditionally been studied by linescan confocal microscopy, but advances in TIRF microscopy together with improved electron-multiplied CCD (EMCCD) cameras now enable rapid (>500 frames s(-1)) imaging of subcellular Ca(2+) signals with high spatial resolution in two dimensions. This approach yields vastly more information (ca. 1 Gb min(-1)) than linescan imaging, rendering visual identification and analysis of local events imaged both laborious and subject to user bias. Here we describe a routine to rapidly automate identification and analysis of local Ca(2+) events. This features an intuitive graphical user-interfaces and runs under Matlab and the open-source Python software. The underlying algorithm features spatial and temporal noise filtering to reliably detect even small events in the presence of noisy and fluctuating baselines; localizes sites of Ca(2+) release with sub-pixel resolution; facilitates user review and editing of data; and outputs time-sequences of fluorescence ratio signals for identified event sites along with Excel-compatible tables listing amplitudes and kinetics of events.

  12. A new ELISA kit which uses a combination of Plasmodium falciparum extract and recombinant Plasmodium vivax antigens as an alternative to IFAT for detection of malaria antibodies

    PubMed Central

    Doderer, Cecile; Heschung, Aurelie; Guntz, Phillippe; Cazenave, Jean-Pierre; Hansmann, Yves; Senegas, Alexandre; Pfaff, Alexander W; Abdelrahman, Tamer; Candolfi, Ermanno

    2007-01-01

    Background The methods most commonly used to measure malarial antibody titres are the Indirect Fluorescence Antibody Test (IFAT), regarded as the gold standard, and the Enzyme-Linked ImmunoSorbent Assay (ELISA). The objective here was to assess the diagnostic performance, i.e. the sensitivity and specificity, of a new malaria antibody ELISA kit in comparison to IFAT. This new ELISA kit, the ELISA malaria antibody test (DiaMed), uses a combination of crude soluble Plasmodium falciparum extract and recombinant Plasmodium vivax antigens. Methods Two groups were used: 95 samples from malaria patients to assess the clinical sensitivity and 2,152 samples from blood donors, who had not been exposed to malaria, to assess the clinical specificity. Results The DiaMed ELISA test kit had a clinical sensitivity of 84.2% and a clinical specificity of 99.6% as compared with 70.5% and 99.6% respectively, using the IFAT method. The ELISA method was more sensitive than the IFAT method for P. vivax infections (75% vs. 25%). However, in 923 malaria risk donors the analytical sensitivity of the ELISA test was 40% and its specificity 98.3%, performances impaired by large numbers of equivocal results non-concordant between ELISA and IFAT. When the overall analytical performances of ELISA was compared to IFAT, the ELISA efficiency J index was 0.84 versus 0.71 for IFAT. Overall analytical sensitivity was 93.1% and the analytical specificity 96.7%. Overall agreement between the two methods reached 0.97 with a reliability k index of 0.64. Conclusion The DiaMed ELISA test kit shows a good correlation with IFAT for analytical and clinical parameters. It may be an interesting method to replace the IFAT especially in blood banks, but further extensive investigations are needed to examine the analytical performance of the assay, especially in a blood bank setting. PMID:17313669

  13. An infrared small target detection algorithm based on high-speed local contrast method

    NASA Astrophysics Data System (ADS)

    Cui, Zheng; Yang, Jingli; Jiang, Shouda; Li, Junbao

    2016-05-01

    Small-target detection in infrared imagery with a complex background is always an important task in remote sensing fields. It is important to improve the detection capabilities such as detection rate, false alarm rate, and speed. However, current algorithms usually improve one or two of the detection capabilities while sacrificing the other. In this letter, an Infrared (IR) small target detection algorithm with two layers inspired by Human Visual System (HVS) is proposed to balance those detection capabilities. The first layer uses high speed simplified local contrast method to select significant information. And the second layer uses machine learning classifier to separate targets from background clutters. Experimental results show the proposed algorithm pursue good performance in detection rate, false alarm rate and speed simultaneously.

  14. 4Pi fluorescence detection and 3D particle localization with a single objective

    PubMed Central

    Schnitzbauer, J.; McGorty, R.; Huang, B.

    2013-01-01

    Coherent detection through two opposing objectives (4Pi configuration) improves the precision of three-dimensional (3D) single-molecule localization substantially along the axial direction, but suffers from instrument complexity and maintenance difficulty. To address these issues, we have realized 4Pi fluorescence detection by sandwiching the sample between the objective and a mirror, and create interference of direct incidence and mirror-reflected signal at the camera with a spatial light modulator. Multifocal imaging using this single-objective mirror interference scheme offers improvement in the axial localization similar to the traditional 4Pi method. We have also devised several PSF engineering schemes to enable 3D localization with a single emitter image, offering better axial precision than normal single-objective localization methods such as astigmatic imaging. PMID:24105517

  15. FTIR imaging of brain tissue reveals crystalline creatine deposits are an ex vivo marker of localized ischemia during murine cerebral malaria: general implications for disease neurochemistry.

    PubMed

    Hackett, Mark J; Lee, Joonsup; El-Assaad, Fatima; McQuillan, James A; Carter, Elizabeth A; Grau, Georges E; Hunt, Nicholas H; Lay, Peter A

    2012-12-19

    Phosphocreatine is a major cellular source of high energy phosphates, which is crucial to maintain cell viability under conditions of impaired metabolic states, such as decreased oxygen and energy availability (i.e., ischemia). Many methods exist for the bulk analysis of phosphocreatine and its dephosphorylated product creatine; however, no method exists to image the distribution of creatine or phosphocreatine at the cellular level. In this study, Fourier transform infrared (FTIR) spectroscopic imaging has revealed the ex vivo development of creatine microdeposits in situ in the brain region most affected by the disease, the cerebellum of cerebral malaria (CM) diseased mice; however, such deposits were also observed at significantly lower levels in the brains of control mice and mice with severe malaria. In addition, the number of deposits was observed to increase in a time-dependent manner during dehydration post tissue cutting. This challenges the hypotheses in recent reports of FTIR spectroscopic imaging where creatine microdeposits found in situ within thin sections from epileptic, Alzheimer's (AD), and amlyoid lateral sclerosis (ALS) diseased brains were proposed to be disease specific markers and/or postulated to contribute to the brain pathogenesis. As such, a detailed investigation was undertaken, which has established that the creatine microdeposits exist as the highly soluble HCl salt or zwitterion and are an ex-vivo tissue processing artifact and, hence, have no effect on disease pathogenesis. They occur as a result of creatine crystallization during dehydration (i.e., air-drying) of thin sections of brain tissue. As ischemia and decreased aerobic (oxidative metabolism) are common to many brain disorders, regions of elevated creatine-to-phosphocreatine ratio are likely to promote crystal formation during tissue dehydration (due to the lower water solubility of creatine relative to phosphocreatine). The results of this study have demonstrated that

  16. Malaria epidemic and drug resistance, Djibouti.

    PubMed

    Rogier, Christophe; Pradines, Bruno; Bogreau, H; Koeck, Jean-Louis; Kamil, Mohamed-Ali; Mercereau-Puijalon, Odile

    2005-02-01

    Analysis of Plasmodium falciparum isolates collected before, during, and after a 1999 malaria epidemic in Djibouti shows that, despite a high prevalence of resistance to chloroquine, the epidemic cannot be attributed to a sudden increase in drug resistance of local parasite populations.

  17. The endothelial protein C receptor and malaria.

    PubMed

    van der Poll, Tom

    2013-08-01

    In this issue of Blood, Moxon et al provide novel insight into the pathogenesis of cerebral malaria, linking loss of the endothelial protein C receptor (EPCR) on brain vessels, caused by cytoadherent infected erythrocytes, with localized coagulation, inflammation, and disruption of endothelial barrier function.

  18. Malaria control in the African Region: perceptions and viewspoints on proceedings of the Africa Leaders Malaria Alliance (ALMA)

    PubMed Central

    2011-01-01

    Background In 2009 a total of 153,408 malaria deaths were reported in Africa. Eleven countries showed a reduction of more than 50% in either confirmed malaria cases or malaria admissions and deaths in recent years. However, many African countries are not on track to achieve the malaria component of the Millennium Development Goal (MDG) 6. The African Leaders Malaria Alliance (ALMA) working session at the 15th African Union Summit discussed the bottlenecks to achieving MDG 6 (specifically halting and beginning to reverse the incidence of malaria by 2015), success factors, and what countries needed to do to accelerate achievement of the MDG. The purpose of this article is to reflect on the proceedings of the ALMA working session. Methods Working methods of the session included speeches and statements by invited speakers and high-level panel discussions. Discussion The main bottlenecks identified related to the capacity of the health systems to deliver quality care and accessibility issues; need for strong, decentralized malaria-control programmes with linkages with other health and development sectors, the civil society and private sector entities; benefits of co-implementation of malaria control programmes with child survival or other public health interventions; systematic application of integrated promotive, preventive, diagnostic and case management interventions with full community participation; adapting approaches to local political, socio-cultural and administrative environments. The following prerequisites for success were identified: a clear vision and effective leadership of national malaria control programmes; high level political commitment to ensure adequate capacity in expertise, skill mix and number of managers, technicians and service providers; national ownership, intersectoral collaboration and accountability, as well as strong civil society and private sector involvement; functional epidemiological surveillance systems; and levering of African

  19. Field experiments of Anopheles gambiae attraction to local fruits/seedpods and flowering plants in Mali to optimize strategies for malaria vector control in Africa using attractive toxic sugar bait methods

    PubMed Central

    2010-01-01

    Background Based on recent studies in Israel demonstrating that attractive toxic sugar bait (ATSB) methods can be used to decimate local anopheline and culicine mosquito populations, an important consideration is whether the same methods can be adapted and improved to attract and kill malaria vectors in Africa. The ATSB approach uses fruit or flower scent as an attractant, sugar solution as a feeding stimulant, and an oral toxin. The ATSB solutions are either sprayed on vegetation or suspended in simple bait stations, and the mosquitoes ingesting the toxic solutions are killed. As such, this approach targets sugar-feeding female and male mosquitoes. This study examines the attractiveness of African malaria vectors to local fruits/seedpods and flowering plants, key biological elements of the ATSB approach for mosquito control. Methods Three field experiments were conducted at sites in Mali. The attraction of Anopheles gambiae s.l. to 26 different local fruits and seedpods was determined at a site in the semi-arid Bandiagara District of Mali. Wire mesh glue traps with fruits/seedpods suspended on skewers inside were set along a seasonal lagoon. Seven replicates of each fruit/seedpod species were tested, with a water-soaked sponge and a sugar-soaked sponge as controls. The attraction of An. gambiae s.l. to 26 different types of flowering plants was determined at a site near Mopti in Mali. The flowering plants held in a water-filled buried container were tested using the same glue traps, with controls including water only and sugar solution. Six replicates of each selected plant type were tested on transects between rice paddies. Additional studies using CDC light traps were done to determine the relative densities and periodicity of An. gambiae s.l. attraction to branches of the most highly attractive flowering plant, branches without flowers, human odor, and candescent light. Results Of the 26 fruits and seedpods tested, 6 were attractive to An. gambiae s.l. females

  20. Improved system for object detection and star/galaxy classification via local subspace analysis.

    PubMed

    Liu, Zhi-Yong; Chiu, Kai-Chun; Xu, Lei

    2003-01-01

    The two traditional tasks of object detection and star/galaxy classification in astronomy can be automated by neural networks because the nature of the problems is that of pattern recognition. A typical existing system can be further improved by using one of the local Principal Component Analysis (PCA) models. Our analysis in the context of object detection and star/galaxy classification reveals that local PCA is not only superior to global PCA in feature extraction, but is also superior to gaussian mixture in clustering analysis. Unlike global PCA which performs PCA for the whole data set, local PCA applies PCA individually to each cluster of data. As a result, local PCA often outperforms global PCA for data of multi-modes. Moreover, since local PCA can effectively avoid the trouble of having to specify a large number of free elements of each covariance matrix of gaussian mixture, it can give a better description of local subspace structures of each cluster when applied on high dimensional data with small sample size. In this paper, the local PCA model proposed by Xu [IEEE Trans. Neural Networks 12 (2001) 822] under the general framework of Bayesian Ying Yang (BYY) normalization learning will be adopted. Endowed with the automatic model selection ability of BYY learning, the BYY normalization learning-based local PCA model can cope with those object detection and star/galaxy classification tasks with unknown model complexity. A detailed algorithm for implementation of the local PCA model will be proposed, and experimental results using both synthetic and real astronomical data will be demonstrated.

  1. A hyperspectral imagery anomaly detection algorithm based on local three-dimensional orthogonal subspace projection

    NASA Astrophysics Data System (ADS)

    Zhang, Xing; Wen, Gongjian

    2015-10-01

    Anomaly detection (AD) becomes increasingly important in hyperspectral imagery analysis with many practical applications. Local orthogonal subspace projection (LOSP) detector is a popular anomaly detector which exploits local endmembers/eigenvectors around the pixel under test (PUT) to construct background subspace. However, this subspace only takes advantage of the spectral information, but the spatial correlat ion of the background clutter is neglected, which leads to the anomaly detection result sensitive to the accuracy of the estimated subspace. In this paper, a local three dimensional orthogonal subspace projection (3D-LOSP) algorithm is proposed. Firstly, under the jointly use of both spectral and spatial information, three directional background subspaces are created along the image height direction, the image width direction and the spectral direction, respectively. Then, the three corresponding orthogonal subspaces are calculated. After that, each vector along three direction of the local cube is projected onto the corresponding orthogonal subspace. Finally, a composite score is given through the three direction operators. In 3D-LOSP, the anomalies are redefined as the target not only spectrally different to the background, but also spatially distinct. Thanks to the addition of the spatial information, the robustness of the anomaly detection result has been improved greatly by the proposed 3D-LOSP algorithm. It is noteworthy that the proposed algorithm is an expansion of LOSP and this ideology can inspire many other spectral-based anomaly detection methods. Experiments with real hyperspectral images have proved the stability of the detection result.

  2. [Microbiological diagnosis of imported malaria].

    PubMed

    Torrús, Diego; Carranza, Cristina; Manuel Ramos, José; Carlos Rodríguez, Juan; Rubio, José Miguel; Subirats, Mercedes; Ta-Tang, Thuy-Huong

    2015-07-01

    Current diagnosis of malaria is based on the combined and sequential use of rapid antigen detection tests (RDT) of Plasmodium and subsequent visualization of the parasite stained with Giemsa solution in a thin and thick blood smears. If an expert microscopist is not available, should always be a sensitive RDT to rule out infection by Plasmodium falciparum, output the result immediately and prepare thick smears (air dried) and thin extensions (fixed with methanol) for subsequent staining and review by an expert microscopist. The RDT should be used as an initial screening test, but should not replace microscopy techniques, which should be done in parallel. The diagnosis of malaria should be performed immediately after clinical suspicion. The delay in laboratory diagnosis (greater than 3 hours) should not prevent the initiation of empirical antimalarial treatment if the probability of malaria is high. If the first microscopic examination and RDT are negative, they must be repeated daily in patients with high suspicion. If suspicion remains after three negative results must be sought the opinion of an tropical diseases expert. Genomic amplification methods (PCR) are useful as confirmation of microscopic diagnosis, to characterize mixed infections undetectable by other methods, and to diagnose asymptomatic infections with submicroscopic parasitaemia.

  3. Effectiveness of Implementation of Electronic Malaria Information System as the National Malaria Surveillance System in Thailand

    PubMed Central

    2016-01-01

    system implemented has achieved its objective. The results of the study suggested that the eMIS helps improve the quality of Thailand’s malaria surveillance system. As the national malaria surveillance system, the eMIS’s functionalities have provided the malaria staff working at the point of care with close-to-real-time case management data quality, covering case detection, case investigation, drug compliance, and follow-up visits. Such features has led to an improvement in the quality of the malaria control program; the government officials now have quicker access to both individual and aggregated data to promptly react to possible outbreak. The eMIS thus plays one of the key roles in moving toward the national goal of malaria elimination by the next decade. PMID:27227156

  4. Osler on typhoid fever: differentiating typhoid from typhus and malaria.

    PubMed

    Cunha, Burke A

    2004-03-01

    Early in the history of medicine, physician had a difficult time differentiating acute febrile illnesses without localizing signs. Typhoid fever and malaria share common features, which caused diagnostic problems during the 1800s. Physician even introduced a new term, typho-malaria, a testimony to their diagnostic confusion. Osler, consummate clinician and careful observer, had vast experience with typhoid fever and malaria. He was able to easily discern between the key features of both of these infections. He also relied on fever patterns to clearly differentiate typhoid fever from malaria. Osler is credited for debunking the term typho-malaria. His clinical description of typhoid fever remains unsurpassed. Clinicians still can benefit greatly from reading Osler's clinical description of typhoid fever.

  5. Epidemiological and ecological aspects related to malaria in the area of influence of the lake at Porto Primavera dam, in western São Paulo State, Brazil.

    PubMed

    Gomes, Almério de C; Paula, Marcia B de; Duarte, Ana Maria R de C; Lima, Maura A; Malafronte, Rosely dos S; Mucci, Luis F; Gotlieb, Sabina Lea D; Natal, Delsio

    2008-01-01

    A study was carried out in the area of influence of the Porto Primavera Hydroelectric Power Station, in western São Paulo State, to investigate ecological and epidemiological aspects of malaria in the area and monitor the profile of the anopheline populations following the environmental changes brought about by the construction of the lake. Mosquitoes captured were analyzed by standardized indicator species analysis (ISA) before and during different flooding phases (253 m and 257 m elevations). The local human population was studied by means of parasitological (thin/thick blood smears), molecular (PCR) and serological tests. Serological tests consisted of Enzyme Linked Immunosorbent Assay (ELISA) with synthetic peptides of the circumsporozoite protein (CSP) from classic Plasmodium vivax, P. vivax variants (VK247 and "vivax-like"), P. malariae and P. falciparum and Indirect Immunofluorescence Assay (IFA) with asexual forms of P. vivax, P. malariae and P. falciparum. The results of the entomological survey indicated that, although the Anopheles darlingi population increased after the flooding, the population density remained very low. No malaria, parasite infection or DNA was detected in the inhabitants of the study area. However, there was a low frequency of antibodies against asexual forms and a significant prevalence of antibodies against P. vivax, P. vivax variants, P. falciparum and P. malariae; the presence of these antibodies may result from recent or less recent contact with human or simian Plasmodium (a parallel study in the same area revealed the existence of a sylvatic cycle). Nevertheless, these results suggest that, as in other places where malaria is present and potential vectors circulate, the local epidemiological conditions observed could potentially support the transmission of malaria in Porto Primavera Lake if infected individuals are introduced in sufficient numbers. Further studies are required to elucidate the phenomena described in this paper.

  6. Socio-Demographics and the Development of Malaria Elimination Strategies in the Low Transmission Setting

    PubMed Central

    Chuquiyauri, Raul; Paredes, Maribel; Peñataro, Pablo; Torres, Sonia; Marin, Silvia; Tenorio, Alexander; Brouwer, Kimberly C.; Abeles, Shira; Llanos-Cuentas, Alejandro; Gilman, Robert H.; Kosek, Margaret; Vinetz, Joseph M.

    2011-01-01

    This analysis presents a comprehensive description of malaria burden and risk factors in Peruvian Amazon villages where malaria transmission is hypoendemic. More than 9,000 subjects were studied in contrasting village settings within the Department of Loreto, Peru, where most malaria occurs in the country. Plasmodium vivax is responsible for more than 75% of malaria cases; severe disease from any form of malaria is uncommon and death rare. The association between lifetime malaria episodes and individual and household covariates was studied using polychotomous logistic regression analysis, assessing effects on odds of some vs. no lifetime malaria episodes. Malaria morbidity during lifetime was strongly associated with age, logging, farming, travel history, and living with a logger or agriculturist. Select groups of adults, particularly loggers and agriculturists acquire multiple malaria infections in transmission settings outside of the main domicile, and may be mobile human reservoirs by which malaria parasites move within and between micro-regions within malaria endemic settings. For example, such individuals might well be reservoirs of transmission by introducing or reintroducing malaria into their home villages and their own households, depending on vector ecology and the local village setting. Therefore, socio-demographic studies can identify people with the epidemiological characteristic of transmission risk, and these individuals would be prime targets against which to deploy transmission blocking strategies along with insecticide treated bednets and chemoprophylaxis. PMID:22100446

  7. Epidemiological risk stratification of malaria in the Americas.

    PubMed

    Castillo-Salgado, C

    1992-01-01

    During the last years, malaria had a significant increase in Latin America, emerging again as one critical health problem in the Region of the Americas. More than 1.04 million new cases were reported in 1990. This resurgence of malaria needed a comprehensive strategy for its prevention and control. National malaria control programs recognized the epidemiological stratification of malaria as a valuable method to assist them in the recognition of local variations and factors that specifically contribute to the level and intensity of transmission in critical malarious areas. Also it serves as a useful instrument for the selection of needed malaria prevention and control activities. The principal feature of this approach is to provide a dynamic and ongoing process for assessing the epidemiological importance of different risk factors (socio-economic, ecological, organization of health services) in malaria transmission. Health interventions are based on this assessment and are aimed directly at the reduction or elimination of the identified risk factors operating at the local level. Intersectorial co-participation and the integration of malaria programs in local health services are also important aspects of this public health approach.

  8. Seasonal prevalence of malaria in West Sumba district, Indonesia

    PubMed Central

    Syafruddin, Din; Krisin; Asih, Puji; Sekartuti; Dewi, Rita M; Coutrier, Farah; Rozy, Ismail E; Susanti, Augustina I; Elyazar, Iqbal RF; Sutamihardja, Awalludin; Rahmat, Agus; Kinzer, Michael; Rogers, William O

    2009-01-01

    Background Accurate information about the burden of malaria infection at the district or provincial level is required both to plan and assess local malaria control efforts. Although many studies of malaria epidemiology, immunology, and drug resistance have been conducted at many sites in Indonesia, there is little published literature describing malaria prevalence at the district, provincial, or national level. Methods Two stage cluster sampling malaria prevalence surveys were conducted in the wet season and dry season across West Sumba, Nusa Tenggara Province, Indonesia. Results Eight thousand eight hundred seventy samples were collected from 45 sub-villages in the surveys. The overall prevalence of malaria infection in the West Sumba District was 6.83% (95% CI, 4.40, 9.26) in the wet season and 4.95% (95% CI, 3.01, 6.90) in the dry. In the wet season Plasmodium falciparum accounted for 70% of infections; in the dry season P. falciparum and Plasmodium vivax were present in equal proportion. Malaria prevalence varied substantially across the district; prevalences in individual sub-villages ranged from 0–34%. The greatest malaria prevalence was in children and teenagers; the geometric mean parasitaemia in infected individuals decreased with age. Malaria infection was clearly associated with decreased haemoglobin concentration in children under 10 years of age, but it is not clear whether this association is causal. Conclusion Malaria is hypoendemic to mesoendemic in West Sumba, Indonesia. The age distribution of parasitaemia suggests that transmission has been stable enough to induce some clinical immunity. These prevalence data will aid the design of future malaria control efforts and will serve as a baseline against which the results of current and future control efforts can be assessed. PMID:19134197

  9. Probable autochthonous Plasmodium vivax malaria transmission in Michigan: case report and epidemiological investigation.

    PubMed

    Sunstrum, J; Elliott, L J; Barat, L M; Walker, E D; Zucker, J R

    2001-12-01

    In September 1995, a Michigan resident with no history of international travel was diagnosed with Plasmodium vivax infection, and local mosquito-borne transmission was suspected. An epidemiological investigation did not identify additional cases of local transmission, and there was no apparent link to the 12 imported malaria cases detected in the region. Potential sites of nighttime outdoor exposure included a campground in a swampy area, close to a racetrack frequented by international travelers, some of whom were known to come from countries with malaria transmission. Entomological investigation identified Anopheles spp. larvae and adults near the campsite. Summer temperatures 4.2 degrees C above average would have contributed to shortened maturation time of P. vivax within the insect vector, increasing the likelihood of infectivity. These investigations indicated that this patient probably acquired P. vivax infection through the bite of a locally infected Anopheles spp. mosquito. Physicians need to consider malaria as a possible cause of unexplained febrile illness, even in the absence of international travel, particularly during the summer months.

  10. Integration of local and global features for anatomical object detection in ultrasound.

    PubMed

    Rahmatullah, Bahbibi; Papageorghiou, Aris T; Noble, J Alison

    2012-01-01

    The use of classifier-based object detection has found to be a promising approach in medical anatomy detection. In ultrasound images, the detection task is very challenging due to speckle, shadows and low contrast characteristic features. Typical detection algorithms that use purely intensity-based image features with an exhaustive scan of the image (sliding window approach) tend not to perform very well and incur a very high computational cost. The proposed approach in this paper achieves a significant improvement in detection rates while avoiding exhaustive scanning, thereby gaining a large increase in speed. Our approach uses the combination of local features from an intensity image and global features derived from a local phase-based image known as feature symmetry. The proposed approach has been applied to 2384 two-dimensional (2D) fetal ultrasound abdominal images for the detection of the stomach and the umbilical vein. The results presented show that it outperforms prior related work that uses only local or only global features.

  11. Dissociation of visual localization and visual detection in rhesus monkeys (Macaca mulatta).

    PubMed

    Andersen, Lau M; Basile, Benjamin M; Hampton, Robert R

    2014-05-01

    Conscious and unconscious cognitive processes contribute independently to human behavior and can be dissociated. For example, humans report failing to see objects clearly in the periphery while simultaneously being able to grasp those objects accurately (Milner in Proc R Soc B Biol Sci 279:2289-2298, 2012). Knowing whether similar dissociations are present in nonverbal species is critical to our understanding of comparative psychology and the evolution of brains. However, such dissociations are difficult to detect in nonhumans because verbal reports of experience are the main way we discriminate putative conscious from unconscious processing. We trained monkeys in a localization task in which they responded to the location where a target appeared, and a matched detection task in which they reported the presence or absence of the same target. We used masking to manipulate the visibility of targets. Accuracy was high in both tasks when stimuli were unmasked and was attenuated by visual masking. At the strongest level of masking, performance in the detection task was at chance, while localization remained significantly above chance. Critically, errors in the detection task were predominantly misses, indicating that the monkeys' behavior remained under stimulus control, but that the monkeys did not detect the target despite above-chance localization. While these results cannot establish the existence of phenomenal vision in monkeys, the dissociation of visually guided action from detection parallels the dissociation of conscious and unconscious vision seen in humans.

  12. Malaria transmission modelling: a network perspective.

    PubMed

    Liu, Jiming; Yang, Bo; Cheung, William K; Yang, Guojing

    2012-11-01

    Malaria transmission can be affected by multiple or even hidden factors, making it difficult to timely and accurately predict the impact of elimination and eradication programs that have been undertaken and the potential resurgence and spread that may continue to emerge. One approach at the moment is to develop and deploy surveillance systems in an attempt to identify them as timely as possible and thus to enable policy makers to modify and implement strategies for further preventing the transmission. Most of the surveillance data will be of temporal and spatial nature. From an interdisciplinary point of view, it would be interesting to ask the following important as well as challenging question: Based on the available surveillance data in temporal and spatial forms, how can we build a more effective surveillance mechanism for monitoring and early detecting the relative prevalence and transmission patterns of malaria? What we can note from the existing clustering-based surveillance software systems is that they do not infer the underlying transmission networks of malaria. However, such networks can be quite informative and insightful as they characterize how malaria transmits from one place to another. They can also in turn allow public health policy makers and researchers to uncover the hidden and interacting factors such as environment, genetics and ecology and to discover/predict malaria transmission patterns/trends. The network perspective further extends the present approaches to modelling malaria transmission based on a set of chosen factors. In this article, we survey the related work on transmission network inference, discuss how such an approach can be utilized in developing an effective computational means for inferring malaria transmission networks based on partial surveillance data, and what methodological steps and issues may be involved in its formulation and validation.

  13. Malaria--a disease of travellers.

    PubMed

    Korzeniewski, Krzysztof; Pieruń, Katarzyna

    2012-01-01

    The number of people travelling to regions with hot climate such as Asia, Africa and South America increases steadily every year. The reason for travel varies greatly, from business trips to tourist excursions, the latter definitely prevailing. There has been an increase in travel to destinations where exposure to vector-borne, food- and water-borne, air-borne or sexually transmitted pathogens is common. As one of vector-borne diseases, malaria poses as a serious health hazard to local as well as immigrant populations. Over 40% of the world's inhabitants live in malaria-endemic regions. Although highly developed countries of North America and Europe are generally free from endemic malaria foci, numerous cases of imported infections are observed. Some cases of malaria are also reported in Poland, they are usually brought by persons returning from tropical regions in Africa, Asia, South America, Australia and Oceania. The number of cases depends on the destination as well as on the use or rejection of chemoprophylaxis. The article provides general information on epidemiology, pathogenesis, clinical manifestation and diagnosis of malaria. Emphasis has been put on treatment as well as on chemoprophylaxis of the disease, which are changing relatively quickly, what is mainly related to increasing Plasmodium resistance to applied medicines.

  14. [Epidemiology and control of malaria in Suriname].

    PubMed

    Rozendaal, J A

    1991-12-01

    Malaria is endemic in the interior of Suriname, which is inhabited by descendants of black slaves and Amerindian tribes. Analysis of epidemiological data for the period 1965-1985 reveals that within that area malaria is endemic only in the territory of the Djuka Indians in the Upper Marowijne region. The endemicity may be due in part to the presence of a relatively large and stable population of the local vector, Anopheles darlingi, and also to the Djukas' frequent travels within their own territory. During 1985, transmission occurred year-round in only two of the many villages of the region, and the majority of cases were found in those same villages. Research following outbreaks of malaria in isolated villages in the plains region and the interior showed that the Djukas employed by the governmental services near these villages probably acted as partially immune carriers of the malaria parasites, transporting them from the reservoir to the villages where the outbreaks occurred. Recommendations are being formulated for the prevention and control of malaria in the interior of Suriname.

  15. Tackling Imported Malaria: An Elimination Endgame

    PubMed Central

    Sturrock, Hugh J. W.; Roberts, Kathryn W.; Wegbreit, Jennifer; Ohrt, Colin; Gosling, Roly D.

    2015-01-01

    As countries move toward malaria elimination, imported infections become increasingly significant as they often represent the majority of cases, can sustain transmission, cause resurgences, and lead to mortality. Here we review and critique current methods to prevent malaria importation in countries pursuing elimination and explore methods applied in other transmission settings and to other diseases that could be transferred to support malaria elimination. To improve intervention targeting we need a better understanding of the characteristics of populations importing infections and their patterns of migration, improved methods to reliably classify infections as imported or acquired locally, and ensure early and accurate diagnosis. The potential for onward transmission in the most receptive and vulnerable locations can be predicted through high-resolution risk mapping that can help malaria elimination or prevention of reintroduction programs target resources. Cross border and regional initiatives can be highly effective when based on an understanding of human and parasite movement. Ultimately, determining the optimal combinations of approaches to address malaria importation will require an evaluation of their impact, cost effectiveness, and operational feasibility. PMID:26013369

  16. Evaluation of sCMOS cameras for detection and localization of single Cy5 molecules.

    PubMed

    Saurabh, Saumya; Maji, Suvrajit; Bruchez, Marcel P

    2012-03-26

    The ability to detect single molecules over the electronic noise requires high performance detector systems. Electron Multiplying Charge-Coupled Device (EMCCD) cameras have been employed successfully to image single molecules. Recently, scientific Complementary Metal Oxide Semiconductor (sCMOS) based cameras have been introduced with very low read noise at faster read out rates, smaller pixel sizes and a lower price compared to EMCCD cameras. In this study, we have compared the two technologies using two EMCCD and three sCMOS cameras to detect single Cy5 molecules. Our findings indicate that the sCMOS cameras perform similar to EMCCD cameras for detecting and localizing single Cy5 molecules.

  17. High-contrast subcutaneous vein detection and localization using multispectral imaging

    NASA Astrophysics Data System (ADS)

    Wang, Fengtao; Behrooz, Ali; Morris, Michael; Adibi, Ali

    2013-05-01

    Multispectral imaging has shown promise in subcutaneous vein detection and localization in human subjects. While many limitations of single-wavelength methods are addressed in multispectral vein detection methods, their performance is still limited by artifacts arising from background skin reflectance and optimality of postprocessing algorithms. We propose a background removal technique that enhances the contrast and performance of multispectral vein detection. We use images acquired at visible wavelengths as reference for removing skin reflectance background from subcutaneous structures in near-infrared images. Results are validated by experiments on human subjects.

  18. Hierarchical leak detection and localization method in natural gas pipeline monitoring sensor networks.

    PubMed

    Wan, Jiangwen; Yu, Yang; Wu, Yinfeng; Feng, Renjian; Yu, Ning

    2012-01-01

    In light of the problems of low recognition efficiency, high false rates and poor localization accuracy in traditional pipeline security detection technology, this paper proposes a type of hierarchical leak detection and localization method for use in natural gas pipeline monitoring sensor networks. In the signal preprocessing phase, original monitoring signals are dealt with by wavelet transform technology to extract the single mode signals as well as characteristic parameters. In the initial recognition phase, a multi-classifier model based on SVM is constructed and characteristic parameters are sent as input vectors to the multi-classifier for initial recognition. In the final decision phase, an improved evidence combination rule is designed to integrate initial recognition results for final decisions. Furthermore, a weighted average localization algorithm based on time difference of arrival is introduced for determining the leak point's position. Experimental results illustrate that this hierarchical pipeline leak detection and localization method could effectively improve the accuracy of the leak point localization and reduce the undetected rate as well as false alarm rate.

  19. Hierarchical Leak Detection and Localization Method in Natural Gas Pipeline Monitoring Sensor Networks

    PubMed Central

    Wan, Jiangwen; Yu, Yang; Wu, Yinfeng; Feng, Renjian; Yu, Ning

    2012-01-01

    In light of the problems of low recognition efficiency, high false rates and poor localization accuracy in traditional pipeline security detection technology, this paper proposes a type of hierarchical leak detection and localization method for use in natural gas pipeline monitoring sensor networks. In the signal preprocessing phase, original monitoring signals are dealt with by wavelet transform technology to extract the single mode signals as well as characteristic parameters. In the initial recognition phase, a multi-classifier model based on SVM is constructed and characteristic parameters are sent as input vectors to the multi-classifier for initial recognition. In the final decision phase, an improved evidence combination rule is designed to integrate initial recognition results for final decisions. Furthermore, a weighted average localization algorithm based on time difference of arrival is introduced for determining the leak point’s position. Experimental results illustrate that this hierarchical pipeline leak detection and localization method could effectively improve the accuracy of the leak point localization and reduce the undetected rate as well as false alarm rate. PMID:22368464

  20. Geographical and environmental approaches to urban malaria in Antananarivo (Madagascar)

    PubMed Central

    2010-01-01

    Background Previous studies, conducted in the urban of Antananarivo, showed low rate of confirmed malaria cases. We used a geographical and environmental approach to investigate the contribution of environmental factors to urban malaria in Antananarivo. Methods Remote sensing data were used to locate rice fields, which were considered to be the principal mosquito breeding sites. We carried out supervised classification by the maximum likelihood method. Entomological study allowed vector species determination from collected larval and adult mosquitoes. Mosquito infectivity was studied, to assess the risk of transmission, and the type of mosquito breeding site was determined. Epidemiological data were collected from November 2006 to December 2007, from public health centres, to determine malaria incidence. Polymerase chain reaction was carried out on dried blood spots from patients, to detect cases of malaria. Rapid diagnostic tests were used to confirm malaria cases among febrile school children in a school survey. A geographical information system was constructed for data integration. Altitude, temperature, rainfall, population density and rice field surface area were analysed and the effects of these factors on the occurrence of confirmed malaria cases were studied. Results Polymerase chain reaction confirmed malaria in 5.1% of the presumed cases. Entomological studies showed An. arabiensis as potential vector. Rice fields remained to be the principal breeding sites. Travel report was considered as related to the occurrence of P. falciparum malaria cases. Conclusion Geographical and environmental factors did not show direct relationship with malaria incidence but they seem ensuring suitability of vector development. Absence of relationship may be due to a lack of statistical power. Despite the presence of An. arabiensis, scarce parasitic reservoir and rapid access to health care do not constitute optimal conditions to a threatening malaria transmission. However

  1. Human movement data for malaria control and elimination strategic planning

    PubMed Central

    2012-01-01

    Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM) in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i) discuss relevant types of HPM across spatial and temporal scales, (ii) document where datasets exist to quantify HPM, (iii) highlight where data gaps remain and (iv) briefly put forward methods for integrating these datasets in a Geographic Information System (GIS) framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements. PMID:22703541

  2. Human movement data for malaria control and elimination strategic planning.

    PubMed

    Pindolia, Deepa K; Garcia, Andres J; Wesolowski, Amy; Smith, David L; Buckee, Caroline O; Noor, Abdisalan M; Snow, Robert W; Tatem, Andrew J

    2012-06-18

    Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM) in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i) discuss relevant types of HPM across spatial and temporal scales, (ii) document where datasets exist to quantify HPM, (iii) highlight where data gaps remain and (iv) briefly put forward methods for integrating these datasets in a Geographic Information System (GIS) framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements.

  3. Limitations of a localized surface plasmon resonance sensor on Salmonella detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have designed a localized surface plasmon resonance (LSPR) biosensor to perform the whole cell detection of Salmonella using gold nanoparticls fabricated by oblique angle deposition technique. The LSPR sensor showed a plasmon peak shift due to the Salmonella antigen and anti-Salmonella antibody r...

  4. Advanced Methods for Passive Acoustic Detection, Classification, and Localization of Marine Mammals

    DTIC Science & Technology

    2015-09-30

    marine mammal vocalizations and ultimately, in some cases, provide data for estimating the population density of the species present. In recent years...pose significant challenges. In this project, we are developing improved methods for detection, classification, and localization of many types of marine mammal sounds.

  5. A local fuzzy method based on “p-strong” community for detecting communities in networks

    NASA Astrophysics Data System (ADS)

    Yi, Shen; Gang, Ren; Yang, Liu; Jia-Li, Xu

    2016-06-01

    In this paper, we propose a local fuzzy method based on the idea of “p-strong” community to detect the disjoint and overlapping communities in networks. In the method, a refined agglomeration rule is designed for agglomerating nodes into local communities, and the overlapping nodes are detected based on the idea of making each community strong. We propose a contribution coefficient to measure the contribution of an overlapping node to each of its belonging communities, and the fuzzy coefficients of the overlapping node can be obtained by normalizing the to all its belonging communities. The running time of our method is analyzed and varies linearly with network size. We investigate our method on the computer-generated networks and real networks. The testing results indicate that the accuracy of our method in detecting disjoint communities is higher than those of the existing local methods and our method is efficient for detecting the overlapping nodes with fuzzy coefficients. Furthermore, the local optimizing scheme used in our method allows us to partly solve the resolution problem of the global modularity. Project supported by the National Natural Science Foundation of China (Grant Nos. 51278101 and 51578149), the Science and Technology Program of Ministry of Transport of China (Grant No. 2015318J33080), the Jiangsu Provincial Post-doctoral Science Foundation, China (Grant No. 1501046B), and the Fundamental Research Funds for the Central Universities, China (Grant No. Y0201500219).

  6. Final report of DOE project "Detection, Localization and Diagnosis of Performance Problems Using PerfSONAR"

    SciTech Connect

    Dovrolis, Konstantinos

    2014-04-15

    We present the development of a middleware service, called Pythia, that is able to detect, localize, and diagnose performance problems in the network paths that interconnect research sites that are of interest to DOE. The proposed service can analyze perfSONAR data collected from all participating sites.

  7. Network-based gene prediction for Plasmodium falciparum malaria towards genetics-based drug discovery

    PubMed Central

    2015-01-01

    Background Malaria is the most deadly parasitic infectious disease. Existing drug treatments have limited efficacy in malaria elimination, and the complex pathogenesis of the disease is not fully understood. Detecting novel malaria-associated genes not only contributes in revealing the disease pathogenesis, but also facilitates discovering new targets for anti-malaria drugs. Methods In this study, we developed a network-based approach to predict malaria-associated genes. We constructed a cross-species network to integrate human-human, parasite-parasite and human-parasite protein interactions. Then we extended the random walk algorithm on this network, and used known malaria genes as the seeds to find novel candidate genes for malaria. Results We validated our algorithms using 77 known malaria genes: 14 human genes and 63 parasite genes were ranked averagely within top 2% and top 4%, respectively among human and parasite genomes. We also evaluated our method for predicting novel malaria genes using a set of 27 genes with literature supporting evidence. Our approach ranked 12 genes within top 1% and 24 genes within top 5%. In addition, we demonstrated that top-ranked candied genes were enriched for drug targets, and identified commonalities underlying top-ranked malaria genes through pathway analysis. In summary, the candidate malaria-associated genes predicted by our data-driven approach have the potential to guide genetics-based anti-malaria drug discovery. PMID:26099491

  8. Estimation of Distribution Algorithm with Local Sampling Strategy for Community Detection in Complex Networks

    NASA Astrophysics Data System (ADS)

    Yu, Fahong; Li, Wenping; He, Feng; Yu, Bolin; Xia, Xiaoyun; Ma, Longhua

    2016-12-01

    It is important to discover the potential community structure for analyzing complex networks. In this paper, an estimation of distribution algorithm with local sampling strategy for community detection in complex networks is presented to optimize the modularity density function. In the proposed algorithm, the evolution probability model is built according to eminent individuals selected by simulated annealing mechanism and a local sampling strategy based on a local similarity model is adopted to improve both the speed and the accuracy for detecting community structure in complex networks. At the same time, a more general version of the criterion function with a tunable parameter λ is used to avoid the resolution limit. Experiments on synthetic and real-life networks demonstrate the performance and the comparison of experimental results with those of several state-of-the-art methods, the proposed algorithm is considerably efficient and competitive.

  9. DETECTION, LOCALIZATION, AND CHARACTERIZATION OF GRAVITATIONAL WAVE BURSTS IN A PULSAR TIMING ARRAY

    SciTech Connect

    Finn, Lee Samuel; Lommen, Andrea N.

    2010-08-01

    Efforts to detect gravitational waves by timing an array of pulsars have traditionally focused on stationary gravitational waves, e.g., stochastic or periodic signals. Gravitational wave bursts-signals whose duration is much shorter than the observation period-will also arise in the pulsar timing array waveband. Sources that give rise to detectable bursts include the formation or coalescence of supermassive black holes (SMBHs), the periapsis passage of compact objects in highly elliptic or unbound orbits about an SMBH, or cusps on cosmic strings. Here, we describe how pulsar timing array data may be analyzed to detect and characterize these bursts. Our analysis addresses, in a mutually consistent manner, a hierarchy of three questions. (1) What are the odds that a data set includes the signal from a gravitational wave burst? (2) Assuming the presence of a burst, what is the direction to its source? (3) Assuming the burst propagation direction, what is the burst waveform's time dependence in each of its polarization states? Applying our analysis to synthetic data sets, we find that we can detect gravitational waves even when the radiation is too weak to either localize the source or infer the waveform, and detect and localize sources even when the radiation amplitude is too weak to permit the waveform to be determined. While the context of our discussion is gravitational wave detection via pulsar timing arrays, the analysis itself is directly applicable to gravitational wave detection using either ground- or space-based detector data.

  10. Outlier Detection in GNSS Pseudo-Range/Doppler Measurements for Robust Localization.

    PubMed

    Zair, Salim; Le Hégarat-Mascle, Sylvie; Seignez, Emmanuel

    2016-04-22

    In urban areas or space-constrained environments with obstacles, vehicle localization using Global Navigation Satellite System (GNSS) data is hindered by Non-Line Of Sight (NLOS) and multipath receptions. These phenomena induce faulty data that disrupt the precise localization of the GNSS receiver. In this study, we detect the outliers among the observations, Pseudo-Range (PR) and/or Doppler measurements, and we evaluate how discarding them improves the localization. We specify a contrario modeling for GNSS raw data to derive an algorithm that partitions the dataset between inliers and outliers. Then, only the inlier data are considered in the localization process performed either through a classical Particle Filter (PF) or a Rao-Blackwellization (RB) approach. Both localization algorithms exclusively use GNSS data, but they differ by the way Doppler measurements are processed. An experiment has been performed with a GPS receiver aboard a vehicle. Results show that the proposed algorithms are able to detect the 'outliers' in the raw data while being robust to non-Gaussian noise and to intermittent satellite blockage. We compare the performance results achieved either estimating only PR outliers or estimating both PR and Doppler outliers. The best localization is achieved using the RB approach coupled with PR-Doppler outlier estimation.

  11. Outlier Detection in GNSS Pseudo-Range/Doppler Measurements for Robust Localization

    PubMed Central

    Zair, Salim; Le Hégarat-Mascle, Sylvie; Seignez, Emmanuel

    2016-01-01

    In urban areas or space-constrained environments with obstacles, vehicle localization using Global Navigation Satellite System (GNSS) data is hindered by Non-Line Of Sight (NLOS) and multipath receptions. These phenomena induce faulty data that disrupt the precise localization of the GNSS receiver. In this study, we detect the outliers among the observations, Pseudo-Range (PR) and/or Doppler measurements, and we evaluate how discarding them improves the localization. We specify a contrario modeling for GNSS raw data to derive an algorithm that partitions the dataset between inliers and outliers. Then, only the inlier data are considered in the localization process performed either through a classical Particle Filter (PF) or a Rao-Blackwellization (RB) approach. Both localization algorithms exclusively use GNSS data, but they differ by the way Doppler measurements are processed. An experiment has been performed with a GPS receiver aboard a vehicle. Results show that the proposed algorithms are able to detect the ‘outliers’ in the raw data while being robust to non-Gaussian noise and to intermittent satellite blockage. We compare the performance results achieved either estimating only PR outliers or estimating both PR and Doppler outliers. The best localization is achieved using the RB approach coupled with PR-Doppler outlier estimation. PMID:27110796

  12. Mothers’ understanding of childhood malaria and practices in rural communities of Ise-Orun, Nigeria: implications for malaria control

    PubMed Central

    Orimadegun, Adebola Emmanuel; Ilesanmi, Kemisola Stella

    2015-01-01

    Introduction: Regular evaluations of communities’ understanding of malaria-related practices are essential for control of the disease in endemic areas. This study was aimed at investigating the perceptions, prevention and treatments practices for childhood malaria by mothers in rural communities. Materials and Methods: We conducted a community-based cross-sectional study at rural communities of Ise-Orun local Government area, Nigeria. We randomly sampled 422 mothers of children less than 5 years and administered a validated questionnaire to assess their perceptions and practices relating to childhood malaria. We used a 10-point scale to assess perception and classified it as good (≥5) or poor (<5). Predictive factors for poor perceptions were identified using logistic regression. Results: Approximately 51% of the mothers had poor perception and 14.2% ascribed malaria illness to mosquito bite only. Majority (85.8%) of the mothers practiced malaria preventive measures, including: Insecticide treated nets (70.0%), chemoprophylaxis (20.1%) and environmental sanitation (44.8%). Of the 200 mothers whose children had malaria fever within the 3 months prior to the study visits, home treatment was adopted by 87.5%. Local herbal remedies were combined with orthodox medicine in the treatments of malaria for 91.5% of the children. The main reasons for not seeking medical treatment at existing formal health facilities were “high cost”, “challenges of access to facilities” and “mothers’ preference for herbal remedies”. Lack of formal education was the only independent predictor of poor malaria perceptions among mothers (OR = 1.91, 95% CI = 1.18, 3.12). Conclusions: Considerable misconceptions about malaria exist among mothers in the rural communities. The implications for malaria control in holoendemic areas are highlighted. PMID:25949972

  13. Helmet-mounted acoustic array for hostile fire detection and localization in an urban environment

    NASA Astrophysics Data System (ADS)

    Scanlon, Michael V.

    2008-04-01

    The detection and localization of hostile weapons firing has been demonstrated successfully with acoustic sensor arrays on unattended ground sensors (UGS), ground-vehicles, and unmanned aerial vehicles (UAVs). Some of the more mature systems have demonstrated significant capabilities and provide direct support to ongoing counter-sniper operations. The Army Research Laboratory (ARL) is conducting research and development for a helmet-mounted system to acoustically detect and localize small arms firing, or other events such as RPG, mortars, and explosions, as well as other non-transient signatures. Since today's soldier is quickly being asked to take on more and more reconnaissance, surveillance, & target acquisition (RSTA) functions, sensor augmentation enables him to become a mobile and networked sensor node on the complex and dynamic battlefield. Having a body-worn threat detection and localization capability for events that pose an immediate danger to the soldiers around him can significantly enhance their survivability and lethality, as well as enable him to provide and use situational awareness clues on the networked battlefield. This paper addresses some of the difficulties encountered by an acoustic system in an urban environment. Complex reverberation, multipath, diffraction, and signature masking by building structures makes this a very harsh environment for robust detection and classification of shockwaves and muzzle blasts. Multifunctional acoustic detection arrays can provide persistent surveillance and enhanced situational awareness for every soldier.

  14. Localized surface plasmon resonance detection of biological toxins using cell surface oligosaccharides on glyco chips.

    PubMed

    Nagatsuka, Takehiro; Uzawa, Hirotaka; Sato, Keita; Kondo, Satoshi; Izumi, Masayuki; Yokoyama, Kenji; Ohsawa, Isaac; Seto, Yasuo; Neri, Paola; Mori, Hiroshi; Nishida, Yoshihiro; Saito, Masato; Tamiya, Eiichi

    2013-05-22

    We have detected biological toxins using localized surface plasmon resonance (LSPR) and synthetic glycosyl ceramides (β-lactoside, globosyl trisaccharide (Gb3), or GM1 pentasaccharide) attached to gold (Au) nanoparticles. The particle diameters ranged from 5-100 nm. The detection sensitivity for three toxins (ricin, Shiga toxin, and cholera toxin) was found to depend not only on the attached glycoside but also on the diameter of the Au nanoparticles. For the detection of ricin, the 20-nm β-lactoside-coated Au nanoparticle exhibited the highest LSPR response, whereas 40-nm Gb3- and GM1-coated Au nanoparticles gave the best results for Shiga toxin and cholera toxin, respectively. In addition, a blocking process on the nanoparticle surface greatly improved the detection sensitivity for cholera toxin. The LSPR system enabled us to detect ricin at 30 ng/mL, Shiga toxin at 10 ng/mL, and the cholera toxin at 20 ng/mL.

  15. Anomaly detection based on PCA and local RXOSP in hyperspectral image

    NASA Astrophysics Data System (ADS)

    Lin, Juan; Gao, Kun; Wang, Lijing; Gong, Xuemei

    2016-10-01

    Aiming at the noise vulnerability and the low detection performance of the classical RX algorithm under the complex background, an improved RX-OSP hyperspectral anomaly detection method is proposed. Firstly, PCA dimension reduction method is applied to suppress the background of hyper-spectral image. Secondly, RX operator is used to detect the pixels owning the most prominent anomaly and the pixels are projected to their orthogonal complement subspaces. Then RXOSP processing is repeated according to the foregoing steps until there is no obvious anomaly. During the process of detection, the covariance matrix is calculated by localization instead of the traditional global approach to reduce the false detection effectively. Finally, ROC curve is adopted as the evaluation index for the experiment results, which reveals that the improved RXOSP algorithm is superior to RX, PCA-RX and RXOSP algorithms.

  16. Distributed Pedestrian Detection Alerts Based on Data Fusion with Accurate Localization

    PubMed Central

    García, Fernando; Jiménez, Felipe; Anaya, José Javier; Armingol, José María; Naranjo, José Eugenio; de la Escalera, Arturo

    2013-01-01

    Among Advanced Driver Assistance Systems (ADAS) pedestrian detection is a common issue due to the vulnerability of pedestrians in the event of accidents. In the present work, a novel approach for pedestrian detection based on data fusion is presented. Data fusion helps to overcome the limitations inherent to each detection system (computer vision and laser scanner) and provides accurate and trustable tracking of any pedestrian movement. The application is complemented by an efficient communication protocol, able to alert vehicles in the surroundings by a fast and reliable communication. The combination of a powerful location, based on a GPS with inertial measurement, and accurate obstacle localization based on data fusion has allowed locating the detected pedestrians with high accuracy. Tests proved the viability of the detection system and the efficiency of the communication, even at long distances. By the use of the alert communication, dangerous situations such as occlusions or misdetections can be avoided. PMID:24008284

  17. Distributed pedestrian detection alerts based on data fusion with accurate localization.

    PubMed

    García, Fernando; Jiménez, Felipe; Anaya, José Javier; Armingol, José María; Naranjo, José Eugenio; de la Escalera, Arturo

    2013-09-04

    Among Advanced Driver Assistance Systems (ADAS) pedestrian detection is a common issue due to the vulnerability of pedestrians in the event of accidents. In the present work, a novel approach for pedestrian detection based on data fusion is presented. Data fusion helps to overcome the limitations inherent to each detection system (computer vision and laser scanner) and provides accurate and trustable tracking of any pedestrian movement. The application is complemented by an efficient communication protocol, able to alert vehicles in the surroundings by a fast and reliable communication. The combination of a powerful location, based on a GPS with inertial measurement, and accurate obstacle localization based on data fusion has allowed locating the detected pedestrians with high accuracy. Tests proved the viability of the detection system and the efficiency of the communication, even at long distances. By the use of the alert communication, dangerous situations such as occlusions or misdetections can be avoided.

  18. Detection of aerosolized varicella-zoster virus DNA in patients with localized herpes zoster.

    PubMed

    Suzuki, Kayoko; Yoshikawa, Tetsushi; Tomitaka, Akiko; Matsunaga, Kayoko; Asano, Yoshizo

    2004-03-15

    We examined the excretion of varicella zoster virus (VZV) in hospitalized patients with herpes zoster localized to the thoracic region whose skin lesions were covered with either hydrocolloid dressing agents (hydrocolloid group) or conventional gauze bandages (gauze group). The presence of VZV DNA in swab samples from lesion coverings, the throat, and filters of air purifiers was examined by use of a sensitive polymerase chain reaction assay. For the hydrocolloid group, VZV was detected in none of the samples from lesion coverings or air purifier filters; for the gauze group, VZV DNA was detected in samples from gauze coverings and air purifier filters for all 6 patients. VZV DNA was detected less frequently in throat samples from patients in the hydrocolloid group than in those from patients in the gauze group. The results of the present study suggest that hydrocolloid dressing agents prevent excretion of aerosolized VZV DNA from skin lesions of patients with localized herpes zoster.

  19. Limitations in the spectral method for graph partitioning: Detectability threshold and localization of eigenvectors.

    PubMed

    Kawamoto, Tatsuro; Kabashima, Yoshiyuki

    2015-06-01

    Investigating the performance of different methods is a fundamental problem in graph partitioning. In this paper, we estimate the so-called detectability threshold for the spectral method with both un-normalized and normalized Laplacians in sparse graphs. The detectability threshold is the critical point at which the result of the spectral method is completely uncorrelated to the planted partition. We also analyze whether the localization of eigenvectors affects the partitioning performance in the detectable region. We use the replica method, which is often used in the field of spin-glass theory, and focus on the case of bisection. We show that the gap between the estimated threshold for the spectral method and the threshold obtained from Bayesian inference is considerable in sparse graphs, even without eigenvector localization. This gap closes in a dense limit.

  20. Limitations in the spectral method for graph partitioning: Detectability threshold and localization of eigenvectors

    NASA Astrophysics Data System (ADS)

    Kawamoto, Tatsuro; Kabashima, Yoshiyuki

    2015-06-01

    Investigating the performance of different methods is a fundamental problem in graph partitioning. In this paper, we estimate the so-called detectability threshold for the spectral method with both un-normalized and normalized Laplacians in sparse graphs. The detectability threshold is the critical point at which the result of the spectral method is completely uncorrelated to the planted partition. We also analyze whether the localization of eigenvectors affects the partitioning performance in the detectable region. We use the replica method, which is often used in the field of spin-glass theory, and focus on the case of bisection. We show that the gap between the estimated threshold for the spectral method and the threshold obtained from Bayesian inference is considerable in sparse graphs, even without eigenvector localization. This gap closes in a dense limit.

  1. Malaria and Vascular Endothelium

    PubMed Central

    de Alencar, Aristóteles Comte; de Lacerda, Marcus Vinícius Guimarães; Okoshi, Katashi; Okoshi, Marina Politi

    2014-01-01

    Involvement of the cardiovascular system in patients with infectious and parasitic diseases can result from both intrinsic mechanisms of the disease and drug intervention. Malaria is an example, considering that the endothelial injury by Plasmodium-infected erythrocytes can cause circulatory disorders. This is a literature review aimed at discussing the relationship between malaria and endothelial impairment, especially its effects on the cardiovascular system. We discuss the implications of endothelial aggression and the interdisciplinarity that should guide the malaria patient care, whose acute infection can contribute to precipitate or aggravate a preexisting heart disease. PMID:25014058

  2. Methods to Increase the Sensitivity of High Resolution Melting Single Nucleotide Polymorphism Genotyping in Malaria.

    PubMed

    Daniels, Rachel; Hamilton, Elizabeth J; Durfee, Katelyn; Ndiaye, Daouda; Wirth, Dyann F; Hartl, Daniel L; Volkman, Sarah K

    2015-11-10

    Despite decades of eradication efforts, malaria remains a global burden. Recent renewed interest in regional elimination and global eradication has been accompanied by increased genomic information about Plasmodium parasite species responsible for malaria, including characteristics of geographical populations as well as variations associated with reduced susceptibility to anti-malarial drugs. One common genetic variation, single-nucleotide polymorphisms (SNPs), offers attractive targets for parasite genotyping. These markers are useful not only for tracking drug resistance markers but also for tracking parasite populations using markers not under drug or other selective pressures. SNP genotyping methods offer the ability to track drug resistance as well as to fingerprint individual parasites for population surveillance, particularly in response to malaria control efforts in regions nearing elimination status. While informative SNPs have been identified that are agnostic to specific genotyping technologies, high-resolution melting (HRM) analysis is particularly suited to field-based studies. Compared to standard fluorescent-probe based methods that require individual SNPs in a single labeled probe and offer at best 10% sensitivity to detect SNPs in samples that contain multiple genomes (polygenomic), HRM offers 2-5% sensitivity. Modifications to HRM, such as blocked probes and asymmetric primer concentrations as well as optimization of amplification annealing temperatures to bias PCR towards amplification of the minor allele, further increase the sensitivity of HRM. While the sensitivity improvement depends on the specific assay, we have increased detection sensitivities to less than 1% of the minor allele. In regions approaching malaria eradication, early detection of emerging or imported drug resistance is essential for prompt response. Similarly, the ability to detect polygenomic infections and differentiate imported parasite types from cryptic local reservoirs

  3. Molecular entomology and prospects for malaria control.

    PubMed Central

    Collins, F. H.; Kamau, L.; Ranson, H. A.; Vulule, J. M.

    2000-01-01

    During the past decade, the techniques of molecular and cell biology have been embraced by many scientists doing research on anopheline vectors of malaria parasites. Some of the most important research advances in molecular entomology have concerned the development of sophisticated molecular tools for procedures such as genetic and physical mapping and germ line transformation. Major advances have also been made in the study of specific biological processes such as insect defence against pathogens and the manner in which malaria parasites and their anopheline hosts interact during sporogony. One of the most important highlights of this research trend has been the emergence during the past year of a formal international Anopheles gambiae genome project, which at present includes investigators in several laboratories in Europe and the USA. Although much of this molecular research is directed towards the development of malaria control strategies that are probably many years from implementation, there are some important areas of molecular entomology that may have a more near-term impact on malaria control. We highlight developments over the past decade in three such areas that we believe can make important contributions to the development of near-term malaria control strategies. These areas are anopheline species identification, the detection and monitoring of insecticide susceptibility/resistance in wild anopheline populations and the determination of the genetic structure of anopheline populations. PMID:11196488

  4. Tools and Strategies for Malaria Control and Elimination: What Do We Need to Achieve a Grand Convergence in Malaria?

    PubMed

    Hemingway, Janet; Shretta, Rima; Wells, Timothy N C; Bell, David; Djimdé, Abdoulaye A; Achee, Nicole; Qi, Gao

    2016-03-01

    Progress made in malaria control during the past decade has prompted increasing global dialogue on malaria elimination and eradication. The product development pipeline for malaria has never been stronger, with promising new tools to detect, treat, and prevent malaria, including innovative diagnostics, medicines, vaccines, vector control products, and improved mechanisms for surveillance and response. There are at least 25 projects in the global malaria vaccine pipeline, as well as 47 medicines and 13 vector control products. In addition, there are several next-generation diagnostic tools and reference methods currently in development, with many expected to be introduced in the next decade. The development and adoption of these tools, bolstered by strategies that ensure rapid uptake in target populations, intensified mechanisms for information management, surveillance, and response, and continued financial and political commitment are all essential to achieving global eradication.

  5. Tools and Strategies for Malaria Control and Elimination: What Do We Need to Achieve a Grand Convergence in Malaria?

    PubMed Central

    Hemingway, Janet; Shretta, Rima; Wells, Timothy N. C.; Bell, David; Djimdé, Abdoulaye A.; Achee, Nicole; Qi, Gao

    2016-01-01

    Progress made in malaria control during the past decade has prompted increasing global dialogue on malaria elimination and eradication. The product development pipeline for malaria has never been stronger, with promising new tools to detect, treat, and prevent malaria, including innovative diagnostics, medicines, vaccines, vector control products, and improved mechanisms for surveillance and response. There are at least 25 projects in the global malaria vaccine pipeline, as well as 47 medicines and 13 vector control products. In addition, there are several next-generation diagnostic tools and reference methods currently in development, with many expected to be introduced in the next decade. The development and adoption of these tools, bolstered by strategies that ensure rapid uptake in target populations, intensified mechanisms for information management, surveillance, and response, and continued financial and political commitment are all essential to achieving global eradication. PMID:26934361

  6. Bacterial coinfections in travelers with malaria: rationale for antibiotic therapy.

    PubMed

    Sandlund, Johanna; Naucler, Pontus; Dashti, Saduddin; Shokri, Akhar; Eriksson, Sara; Hjertqvist, Marika; Karlsson, Lillemor; Capraru, Teodor; Färnert, Anna

    2013-01-01

    Malaria predisposes children in areas where malaria is endemic to concurrent bacteremia, often with severe outcomes. The importance of bacterial coinfections in patients diagnosed with malaria in nonendemic settings has, however, not been reported. A retrospective analysis of microbiology data was performed in 755 travelers diagnosed with malaria in Sweden. Bacterial cultures from blood and other locations were correlated to clinical outcome and antibiotic treatment. Blood cultures were drawn from 417 (55%) patients (88% of whom were >15 years old), and bacterial isolates of clinical relevance (Salmonella enterica serovar Enteritidis and Escherichia coli) were detected in 2 patients (0.3%). Cultures from other locations (mainly urine, nasopharyngeal, and fecal samples) were obtained from 44% of the patients with 4.9% positivity. Of the 38 patients given antibiotics, 47% had neither severe malaria nor positive cultures and/or radiology signs indicative of treatment. C-reactive protein levels were associated with bacterial infections but had only a fair predictive value. Bacterial coinfections are uncommon among travelers with malaria. These data suggest a weaker association between malaria and bacteremia than previously described in endemic settings and might indicate different patient populations with different pathophysiological mechanisms and microbial environments. The study supports a restrictive antibiotic policy in returning travelers with malaria.

  7. The Utility of Malaria Rapid Diagnostic Tests as a Tool in Enhanced Surveillance for Malaria Elimination in Vanuatu

    PubMed Central

    Guintran, Jean-Olivier; Iata, Harry; Anderson, Karen; Nausien, Johnny; Gresty, Karryn J; Waters, Norman C.; Vestergaard, Lasse S.; Taleo, George; Cheng, Qin

    2016-01-01

    Background As part of efforts to eliminate malaria, Vanuatu has piloted the implementation of enhanced malaria surveillance and response strategies since 2011. This involves passive case detection (PCD) in health facilities, proactive case detection (Pro-ACD) and reactive case detection (Re-ACD) in communities using malaria rapid diagnostic tests (RDTs). While RDTs improve case management, their utility for detection of malaria infections in ACDs in this setting is unclear. Methods The utility of malaria RDTs as diagnostic tools was evaluated in PCD, in five rounds of Pro-ACDs and five rounds of Re-ACDs conducted in Tafea and Torba Provinces between 2011 and 2014. The number of malaria infections detected by RDTs was compared to that detected by PCR from collected used-RDTs. Results PCD in Tafea Province (2013) showed a RDT-positive rate of 0.21% (2/939) and a PCR-positive rate of 0.44% (2/453), indicating less than 1% of suspected malaria cases in Tafea Province were due to malaria. In Pro-ACDs conducted in Tafea and Torba Provinces, RDT-positive rates in 2013 and 2014 were 0.14% (3/2145) and 0% (0/2823), respectively, while the corresponding PCR-positive rates were 0.72% (9/1242) and 0.79% (9/1141). PCR identified villages in both provinces appearing to be transmission foci with a small number of low-density infections, mainly P. falciparum infections. In five rounds of Re-ACD, RDTs did not identify any additional infections while PCR detected only one among 173 subjects screened. Conclusions PCD and Pro-ACDs demonstrate that both Tafea and Torba Provinces in Vanuatu has achieved very low malaria prevalence. In these low-transmission areas, conducting Pro-ACD and Re-ACDs using RDTs appears not cost-effective and may have limited impact on interrupting malaria transmission due to the small number of infections identified by RDTs and considerable operational resources invested. More sensitive, field deployable and affordable diagnostic tools will improve malaria

  8. Rapid Urban Malaria Appraisal (RUMA) III: epidemiology of urban malaria in the municipality of Yopougon (Abidjan)

    PubMed Central

    Wang, Shr-Jie; Lengeler, Christian; Smith, Thomas A; Vounatsou, Penelope; Cissé, Guéladio; Tanner, Marcel

    2006-01-01

    Background Currently, there is a significant lack of knowledge concerning urban malaria patterns in general and in Abidjan in particular. The prevalence of malaria, its distribution in the city and the fractions of fevers attributable to malaria in the health facilities have not been previously investigated. Methods A health facility-based survey and health care system evaluation was carried out in a peripheral municipality of Abidjan (Yopougon) during the rainy season of 2002, applying a standardized Rapid Urban Malaria Appraisal (RUMA) methodology. Results According to national statistics, approximately 240,000 malaria cases (both clinical cases and laboratory confirmed cases) were reported by health facilities in the whole of Abidjan in 2001. They accounted for 40% of all consultations. In the health facilities of the Yopougon municipality, the malaria infection rates in fever cases for different age groups were 22.1% (under one year-olds), 42.8% (one to five years-olds), 42.0% (> five to 15 years-olds) and 26.8% (over 15 years-olds), while those in the control group were 13.0%. 26.7%, 21.8% and 14.6%, respectively. The fractions of malaria-attributable fever were 0.12, 0.22, 0.27 and 0.13 in the same age groups. Parasitaemia was homogenously detected in different areas of Yopougon. Among all children, 10.1% used a mosquito net (treated or not) the night before the survey and this was protective (OR = 0.52, 95% CI 0.29–0.97). Travel to rural areas within the last three months was frequent (31% of all respondents) and associated with a malaria infection (OR = 1.75, 95% CI 1.25–2.45). Conclusion Rapid urbanization has changed malaria epidemiology in Abidjan and endemicity was found to be moderate in Yopougon. Routine health statistics are not fully reliable to assess the burden of disease, and the low level of the fractions of malaria-attributable fevers indicated substantial over-treatment of malaria. PMID:16584575

  9. ASSESSMENT OF THREE BLOOD GENOMIC-DNA PREPARATION METHODS FOR MALARIA MOLECULAR DIAGNOSIS.

    PubMed

    Al-Harti, Saeed A

    2016-04-01

    Species-specific PCR techniques are highly sensitive and reliable alternatives to classical methods for malaria diagnosis and speciation, especially in endemic regions under advanced control or elimination programs where asymptomatic and low-density infections are increasingly reported. Nevertheless, the performance of these techniques is directly affected by the quality of isolated DNA templates. A Plasmodium falciparum/vivax-specific diagnostic Nested-PCR (Pƒ/Pv N-PCR) was used to assess three DNA preparation methods, Qiagen® Mini-Chromatographic kit (QIAmp®) and Jena-Biosciences® DNA isolation kit (JB®) for genomic DNA extraction from EDTA-preserved whole blood samples, and Whatman-FTA® purification reagent (FTA®) for DNA preparation from dry blood spots (DBS) collected onto FTA®- cards. A total of 84 out of 137 blood specimens collected from malaria suspicious febrile patients who visited five health care centres in south-western endemic localities of Saudi Arabia were found P. falciparum positive by at least one method. Among these, only 76 (90%) were reported P. falciparum malaria positive by two expert microscopists. No other species of Plasmodium were detected. Pƒ/Pv N-PCR revealed 84/84 (100%), 75/84 (89%), and 81 (96%) P. falciparum positive samples using DNA templates prepared by QIAmp®, JB®, and FTA® purification methods, respectively. Therefore, Pƒ/Pv N-PCR, when applied to QIAmp® DNA templates showed to be a highly sensitive diagnostic method, particularly useful for submicroscopic specimens from clinically malaria suspicious patients in endemic areas. On the other hand, Pƒ/Pv N-PCR of FTA®-DBS DNA templates revealed 5 positive cases missed by microscopy, encouraging its use as an affordable field semi-adapted protocol for malaria active screening, especially in remqte rural regions with limited laboratory infrastructure.

  10. Species Composition and Diversity of Malaria Vector Breeding Habitats in Trincomalee District of Sri Lanka

    PubMed Central

    Gunathilaka, Nayana; Abeyewickreme, Wimaladharma; Hapugoda, Menaka; Wickremasinghe, Rajitha

    2015-01-01

    Introduction. Mosquito larval ecology is important in determining larval densities and species assemblage. This in turn influences malaria transmission in an area. Therefore, understanding larval habitat ecology is important in designing malaria control programs. Method. Larval surveys were conducted in 20 localities under five sentinel sites (Padavisiripura, Gomarankadawala, Thoppur, Mollipothana, and Ichchallampaththu) in Trincomalee District, Eastern Province of Sri Lanka, between June 2010 and July 2013. The relationship between seven abiotic variables (temperature, pH, conductivity, Total Dissolved Solid (TDS), turbidity, Dissolved Oxygen (DO), and salinity) was measured. Results. A total of 21,347 anophelines were recorded representing 15 species. Anopheles subpictus 24.72% (5,278/21,347) was the predominant species, followed by 24.67% (5,267/21,347) of An. nigerrimus and 14.56% (3,109/21,347) of An. peditaeniatus. A total of 9,430 breeding habitats under twenty-one categories were identified. An. culcicifacies was noted to be highest from built wells (20.5%) with high salinity (1102.3 ± 81.8 mg/L), followed by waste water collections (20.2%) having low DO levels (2.85 ± 0.03 mg/L) and high TDS (1,654 ± 140 mg/L). Conclusion. This study opens an avenue to explore new breeding habitats of malaria vectors in the country and reemphasizes the requirement of conducting entomological surveillance to detect potential transmission of malaria in Sri Lanka under the current malaria elimination programme. PMID:26583136

  11. Rapid guided wave delamination detection and quantification in composites using global-local sensing

    NASA Astrophysics Data System (ADS)

    Tian, Zhenhua; Yu, Lingyu; Leckey, Cara

    2016-08-01

    This paper presents a rapid guided ultrasonic wave inspection approach through global inspection by phased array beamforming and local damage evaluation via wavenumber analysis. The global-local approach uses a hybrid system consisting of a PZT wafer and a non-contact laser vibrometer. The overall inspection is performed in two steps. First, a phased array configured by a small number of measurements performs beamforming and beamsteering over the entire plate in order to detect and locate the presence of the damage. A local area is identified as target damage area for the second step. Then a high density wavefield measurement is taken over the target damage area and a spatial wavenumber imaging is performed to quantitatively evaluate the damage. The two-step inspection has been applied to locate and quantify impact-induced delamination damage in a carbon fiber reinforced polymer composite plate. The detected delamination location, size and shape agree well with those of an ultrasonic C-scan. For the test case studied in this work the global-local approach reduced the total composite inspection (damage detection and characterization) time by ∼97% compared to using a full scan approach.

  12. Are Exam Questions Known in Advance? Using Local Dependence to Detect Cheating.

    PubMed

    Zimmermann, Stefan; Klusmann, Dietrich; Hampe, Wolfgang

    2016-01-01

    Cheating is a common phenomenon in high stakes admission, licensing and university exams and threatens their validity. To detect if some exam questions had been affected by cheating, we simulated how data would look like if some test takers possessed item preknowledge: Responses to a small number of items were set to correct for 1-10% of test takers. Item difficulty, item discrimination, item fit, and local dependence were computed using an IRT 2PL model. Then changes in these item properties from the non-compromised to the compromised dataset were scrutinized for their sensitivity to item preknowledge. A decline in the discrimination parameter compared with previous test versions and an increase in local item dependence turned out to be the most sensitive indicators of item preknowledge. A multiplicative combination of shifts in item discrimination, item difficulty, and local item dependence detected item preknowledge with a sensitivity of 1.0 and a specificity of .95 if 11 of 80 items were preknown to 10% of the test takers. Cheating groups smaller than 5% of the test takers were not detected reliably. In the discussion, we outline an effective search for items affected by cheating, which would enable faculty staff without IRT knowledge to detect compromised items and exclude them from scoring.

  13. Low-frequency phased-array 2D fluorescence localization in breast cancer detection

    NASA Astrophysics Data System (ADS)

    Liu, Qian; Chen, Yu; Chance, Britton; Luo, Qingming

    2003-12-01

    A method for rapid, non-invasive 2D fluorescence localization of breast cancer using low frequency phased array near-infrared technique is presented in this article. In our study, we have developed a dual-channel fluorescence detection system to locate breast cancer. This system consists two pair of in-phase and out-of-phase light emitting diodes (LEDs) as the light sources and Photomultiplier Tube (PMT) as the detector. Two null planes generated by cancellation of diffusion photon density waves (DPDW) will indicate the 2D position of breast cancer with exogenous contrast agents. The fluorescent contrast agent used in this study is Indocyanine Green (ICG) and the minimum amount of ICG detected by our system is 0.5 μM. With the 2 cm separation of sources and detector, the maximum depth our system can detect is 10 mm. The whole system is in compact size and portable. Phantom experiments show that the system can provide real time detection and localization of small hidden absorbing-fluorescent objects inside the highly scattering medium with high accuracy of +/-3 mm. The potential application is that it is low-cost and can be used for breast cancer localization as operation aid and self-examination.

  14. Convolution Comparison Pattern: An Efficient Local Image Descriptor for Fingerprint Liveness Detection.

    PubMed

    Gottschlich, Carsten

    2016-01-01

    We present a new type of local image descriptor which yields binary patterns from small image patches. For the application to fingerprint liveness detection, we achieve rotation invariant image patches by taking the fingerprint segmentation and orientation field into account. We compute the discrete cosine transform (DCT) for these rotation invariant patches and attain binary patterns by comparing pairs of two DCT coefficients. These patterns are summarized into one or more histograms per image. Each histogram comprises the relative frequencies of pattern occurrences. Multiple histograms are concatenated and the resulting feature vector is used for image classification. We name this novel type of descriptor convolution comparison pattern (CCP). Experimental results show the usefulness of the proposed CCP descriptor for fingerprint liveness detection. CCP outperforms other local image descriptors such as LBP, LPQ and WLD on the LivDet 2013 benchmark. The CCP descriptor is a general type of local image descriptor which we expect to prove useful in areas beyond fingerprint liveness detection such as biological and medical image processing, texture recognition, face recognition and iris recognition, liveness detection for face and iris images, and machine vision for surface inspection and material classification.

  15. The Mayo Lung Project for early detection and localization of bronchogenic carcinoma: a status report.

    PubMed

    Fontana, R S; Sanderson, D R; Woolner, L B; Miller, W E; Bernatz, P E; Payne, W S; Taylor, W F

    1975-05-01

    The Mayo Lung Project (MLP) is a screening program designed to detect bronchogenic carcinoma at a curable stage. Screening tests include chest roentgenograms, three-day "pooled" sputum cytology studies, and lung-health questionnaires. These are being applied every four months to a study population of outpatients who have a high probability of developing lung cancer. Initial patient acceptance of the screening program has been excellent. Small asymptomatic lung cancers have been detected both roentgenographically and cytologically. The two procedures have complemented each other with little overlap. Chest roentgenography has proved most useful in diagnosing peripherally situated cancers, whereas sputum cytology studies have been most effective in identifying early squamous cancer involving major airways. At present, more cancers have been detected roentgenographically than cytologically, but the cytologically detected cases appear to have a better prognosis. Roentgenographically occult cancers have been localized with regularity, although the localization process is complicated. Theoretically, vigorous application of radiologic and cytologic screening, combined with optimum use of localizing procedures and treatment, could increase the five-year survival rate among lung cancer patients to nearly 50 percent. However, the actual survivorship attained will ultimately be determined by currently imponderable factors such as patient acceptance of longterm screening, frequency of multicentric respiratory cancers, and incidence of noncancerous smoking-related diseases, especially chronic obstructive pulmonary disease and ischemic heart disease.

  16. Are Exam Questions Known in Advance? Using Local Dependence to Detect Cheating

    PubMed Central

    Zimmermann, Stefan; Klusmann, Dietrich; Hampe, Wolfgang

    2016-01-01

    Cheating is a common phenomenon in high stakes admission, licensing and university exams and threatens their validity. To detect if some exam questions had been affected by cheating, we simulated how data would look like if some test takers possessed item preknowledge: Responses to a small number of items were set to correct for 1–10% of test takers. Item difficulty, item discrimination, item fit, and local dependence were computed using an IRT 2PL model. Then changes in these item properties from the non-compromised to the compromised dataset were scrutinized for their sensitivity to item preknowledge. A decline in the discrimination parameter compared with previous test versions and an increase in local item dependence turned out to be the most sensitive indicators of item preknowledge. A multiplicative combination of shifts in item discrimination, item difficulty, and local item dependence detected item preknowledge with a sensitivity of 1.0 and a specificity of .95 if 11 of 80 items were preknown to 10% of the test takers. Cheating groups smaller than 5% of the test takers were not detected reliably. In the discussion, we outline an effective search for items affected by cheating, which would enable faculty staff without IRT knowledge to detect compromised items and exclude them from scoring. PMID:27907190

  17. Convolution Comparison Pattern: An Efficient Local Image Descriptor for Fingerprint Liveness Detection

    PubMed Central

    Gottschlich, Carsten

    2016-01-01

    We present a new type of local image descriptor which yields binary patterns from small image patches. For the application to fingerprint liveness detection, we achieve rotation invariant image patches by taking the fingerprint segmentation and orientation field into account. We compute the discrete cosine transform (DCT) for these rotation invariant patches and attain binary patterns by comparing pairs of two DCT coefficients. These patterns are summarized into one or more histograms per image. Each histogram comprises the relative frequencies of pattern occurrences. Multiple histograms are concatenated and the resulting feature vector is used for image classification. We name this novel type of descriptor convolution comparison pattern (CCP). Experimental results show the usefulness of the proposed CCP descriptor for fingerprint liveness detection. CCP outperforms other local image descriptors such as LBP, LPQ and WLD on the LivDet 2013 benchmark. The CCP descriptor is a general type of local image descriptor which we expect to prove useful in areas beyond fingerprint liveness detection such as biological and medical image processing, texture recognition, face recognition and iris recognition, liveness detection for face and iris images, and machine vision for surface inspection and material classification. PMID:26844544

  18. A RF time domain approach for electric arcs detection and localization systems

    NASA Astrophysics Data System (ADS)

    Deacu, Daniela; Tamas, Razvan; Petrescu, Teodor; Paun, Mirel; Anchidin, Liliana; Algiu, Madalina

    2016-12-01

    In this paper we propose a new method for detection and localization of electric arcs by using two ultra-wide band (UWB) antennas together with data processing in the time-domain. The source of electric arcs is localized by computing an average on the inter-correlation functions of the signals received on two channels. By calculating the path length difference to the antennas, the direction of the electric arcs is then found. The novelty of the method consists in the spatial averaging in order to reduce the incertitude caused by the finite sampling rate.

  19. Blind Detection of Digital Forgery Image Based on the Local Entropy of the Gradient

    NASA Astrophysics Data System (ADS)

    Li, Zhe; Zheng, Jiang-Bin

    A novel method based on the local entropy of the gradient is proposed to detect the forged digital images. The method can discover some traces of artificial feather operation, which is necessary to create a smooth transition between a forged image region and its surroundings. The local entropy of the gradient is used to determine the forged region, and the credibility is computed to show the reality level of the image. Results of experiments on several forged images demonstrate the effectiveness of the algorithm.

  20. MALARIA RESEARCH PROGRAM.

    DTIC Science & Technology

    Analytical clinical summaries are presented on the following: Summary and analysis of therapeutic effect of new drugs in human volunteers with...Falciparum Malaria; Summary and analysis of therapeutic effect of new drugs in human volunteers with Vivax Malaria; Potentiation by drug combination...Problems of resistance for both old and new drugs ; Analysis of P. berghei infections; Studies on mechanisms of drug action; Cumulative summary of all new drug trials.

  1. Malaria in pregnancy.

    PubMed

    Alvarez, Jesus R; Al-Khan, Abdulla; Apuzzio, Joseph J

    2005-12-01

    Recently, there has been a resurgence of malaria in densely populated areas of the United States secondary to human migration from endemic areas where factors such as cessation of vector control, vector resistance to insecticides, disease resistance to drugs, environmental changes, political instability, and indifference, have played a role for malaria becoming an overwhelming infection of these tropical underdeveloped countries. It is important for health care providers of gravida to be alert of the disease and its effects on pregnancy.

  2. A New Approach for Copy-Move Detection Based on Improved Weber Local Descriptor.

    PubMed

    Saadat, Shabnam; Moghaddam, Mohsen Ebrahimi; Mohammadi, Mohsen

    2015-11-01

    One of the most common image tampering techniques is copy-move; in this technique, one or more parts of the image are copied and pasted in another area of the image. Recently, various methods have been proposed for copy-move detection; however, many of these techniques are not robust to additional changes like geometric transformation, and they are failed to be useful for detecting small copied areas. In this paper, a new method based on point descriptors which are derived from the integration of textural feature-based Weber law and statistical features of the image is presented. In this proposed approach, modified multiscale version of Weber local descriptor is presented to make the method robust versus geometric transformation and detect small copied areas. The results of the experiments showed that our method can detect small copied areas and copy-move tampered images which are influenced by rotation, scaling, noise addition, compression, blurring, and mirroring.

  3. Local concurrent error detection and correction in data structures using virtual backpointers

    NASA Technical Reports Server (NTRS)

    Li, Chung-Chi Jim; Chen, Paul Peichuan; Fuchs, W. Kent

    1989-01-01

    A new technique, based on virtual backpointers, for local concurrent error detection and correction in linked data strutures is presented. Two new data structures, the Virtual Double Linked List, and the B-tree with Virtual Backpointers, are described. For these structures, double errors can be detected in 0(1) time and errors detected during forward moves can be corrected in 0(1) time. The application of a concurrent auditor process to data structure error detection and correction is analyzed, and an implementation is described, to determine the effect on mean time to failure of a multi-user shared database system. The implementation utilizes a Sequent shared memory multiprocessor system operating on a shared database of Virtual Double Linked Lists.

  4. Local concurrent error detection and correction in data structures using virtual backpointers

    NASA Technical Reports Server (NTRS)

    Li, C. C.; Chen, P. P.; Fuchs, W. K.

    1987-01-01

    A new technique, based on virtual backpointers, for local concurrent error detection and correction in linked data structures is presented. Two new data structures, the Virtual Double Linked List, and the B-tree with Virtual Backpointers, are described. For these structures, double errors can be detected in 0(1) time and errors detected during forward moves can be corrected in 0(1) time. The application of a concurrent auditor process to data structure error detection and correction is analyzed, and an implementation is described, to determine the effect on mean time to failure of a multi-user shared database system. The implementation utilizes a Sequent shared memory multiprocessor system operating on a shared databased of Virtual Double Linked Lists.

  5. ARX model-based gearbox fault detection and localization under varying load conditions

    NASA Astrophysics Data System (ADS)

    Yang, Ming; Makis, Viliam

    2010-11-01

    The development of the fault detection schemes for gearbox systems has received considerable attention in recent years. Both time series modeling and feature extraction based on wavelet methods have been considered, mostly under constant load. Constant load assumption implies that changes in vibration data are caused only by deterioration of the gearbox. However, most real gearbox systems operate under varying load and speed which affect the vibration signature of the system and in general make it difficult to recognize the occurrence of an impending fault. This paper presents a novel approach to detect and localize the gear failure occurrence for a gearbox operating under varying load conditions. First, residual signal is calculated using an autoregressive model with exogenous variables (ARX) fitted to the time-synchronously averaged (TSA) vibration data and filtered TSA envelopes when the gearbox operated under various load conditions in the healthy state. The gear of interest is divided into several sections so that each section includes the same number of adjacent teeth. Then, the fault detection and localization indicator is calculated by applying F-test to the residual signal of the ARX model. The proposed fault detection scheme indicates not only when the gear fault occurs, but also in which section of the gear. Finally, the performance of the fault detection scheme is checked using full lifetime vibration data obtained from the gearbox operating from a new condition to a breakdown under varying load.

  6. A localized double-quantum filter for the in vivo detection of brain glucose.

    PubMed

    Keltner, J R; Wald, L L; Ledden, P J; Chen, Y C; Matthews, R T; Küestermann, E H; Baker, J R; Rosen, B R; Jenkins, B G

    1998-04-01

    A double-quantum filter (DQF) sequence with PRESS localization was developed for in vivo detection of the glucose resonances in the 3.85-ppm region of the brain proton spectrum. The efficiency and spectral editing characteristics were studied in phantom and animal experiments. Approximately 45% detection efficiency was achieved at 4.7 T with TE = 68 ms. Since the efficiency of the DQF method is dependent on the relative phases of the RF pulses, a phase calibration procedure was used to correct for phase shifts induced by the spatial localization. In addition to detecting the 3.85-ppm glucose resonances with approximately 45% efficiency, the DQF sequence simultaneously detects 1.3-ppm lactate resonance with approximately 20% efficiency. The use of the DQF technique for simultaneously monitoring both the input and output of anaerobic glycolysis in the brain was demonstrated by detecting brain glucose and lactate in the same acquisition after iv injection of glucose followed by the induction of global ischemia.

  7. Glaucoma detection using novel optic disc localization, hybrid feature set and classification techniques.

    PubMed

    Akram, M Usman; Tariq, Anam; Khalid, Shehzad; Javed, M Younus; Abbas, Sarmad; Yasin, Ubaid Ullah

    2015-12-01

    Glaucoma is a chronic and irreversible neuro-degenerative disease in which the neuro-retinal nerve that connects the eye to the brain (optic nerve) is progressively damaged and patients suffer from vision loss and blindness. The timely detection and treatment of glaucoma is very crucial to save patient's vision. Computer aided diagnostic systems are used for automated detection of glaucoma that calculate cup to disc ratio from colored retinal images. In this article, we present a novel method for early and accurate detection of glaucoma. The proposed system consists of preprocessing, optic disc segmentation, extraction of features from optic disc region of interest and classification for detection of glaucoma. The main novelty of the proposed method lies in the formation of a feature vector which consists of spatial and spectral features along with cup to disc ratio, rim to disc ratio and modeling of a novel mediods based classier for accurate detection of glaucoma. The performance of the proposed system is tested using publicly available fundus image databases along with one locally gathered database. Experimental results using a variety of publicly available and local databases demonstrate the superiority of the proposed approach as compared to the competitors.

  8. Acoustic detection and localization of weapons fire by unattended ground sensors and aerostat-borne sensors

    NASA Astrophysics Data System (ADS)

    Naz, P.; Marty, Ch.; Hengy, S.; Miller, L. S.

    2009-05-01

    The detection and localization of artillery guns on the battlefield is envisaged by means of acoustic and seismic waves. The main objective of this work is to examine the different frequency ranges usable for the detection of small arms, mortars, and artillery guns on the same hardware platform. The main stages of this study have consisted of: data acquisition of the acoustic signals of the different weapons used, signal processing and evaluation of the localization performance for various types of individual arrays, and modeling of the wave propagation in the atmosphere. The study of the propagation effects on the signatures of these weapons is done by comparing the acoustic signals measured during various days, at ground level and at the altitude of our aerostat (typically 200 m). Numerical modeling has also been performed to reinforce the interpretation of the experimental results.

  9. Graph-Theoretic Statistical Methods for Detecting and Localizing Distributional Change in Multivariate Data

    DTIC Science & Technology

    2015-06-01

    THEORETIC STATISTICAL METHODS FOR DETECTING AND LOCALIZING DISTRIBUTIONAL CHANGE IN MULTIVARIATE DATA by Matthew A. Hawks June 2015...existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this...DISTRIBUTIONAL CHANGE IN MULTIVARIATE DATA 5. FUNDING NUMBERS 6. AUTHOR(S) Hawks, Matthew A. 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES

  10. Wavelet-based analysis of electroencephalogram (EEG) signals for detection and localization of epileptic seizures

    NASA Astrophysics Data System (ADS)

    Benke, George; Bozek-Kuzmicki, Maribeth; Colella, David; Jacyna, Garry M.; Benedetto, John J.

    1995-04-01

    A wavelet-based technique WISP is used to discriminate normal brain activity from brain activity during epileptic seizures. The WISP technique is used to exploit the noted difference in frequency content during the normal brain state and the seizure brain state so that detection and localization decisions can be made. An AR-Pole statistic technique is used as a comparative measure to base-line the WISP performance.

  11. Graphical rule of transforming continuous-variable graph states by local homodyne detection

    SciTech Connect

    Zhang Jing

    2010-09-15

    Graphical rule, describing that any single-mode homodyne detection turns a given continuous-variable (CV) graph state into a new one, is presented. Employing two simple graphical rules--local complement operation and vertex deletion (single quadrature-amplitude x measurement)--the graphical rule for any single-mode quadrature component measurement can be obtained. The shape of CV weighted graph state may be designed and constructed easily from a given larger graph state by applying this graphical rule.

  12. Think Locally, Act Locally: The Detection of Small, Medium-Sized, and Large Communities in Large Networks

    PubMed Central

    Jeub, Lucas G. S.; Balachandran, Prakash; Porter, Mason A.; Mucha, Peter J.; Mahoney, Michael W.

    2016-01-01

    , for many large realistic networks, the output of locally-biased methods that focus on communities that are centered around a given seed node might have better conceptual grounding and greater practical utility than the output of global community-detection methods. They also illustrate subtler structural properties that are important to consider in the development of better benchmark networks to test methods for community detection. PMID:25679670

  13. Robotic vehicle uses acoustic array for detection and localization in urban environments

    NASA Astrophysics Data System (ADS)

    Young, Stuart H.; Scanlon, Michael V.

    2001-09-01

    Sophisticated robotic platforms with diverse sensor suites are quickly replacing the eyes and ears of soldiers on the complex battlefield. The Army Research Laboratory (ARL) in Adelphi, Maryland has developed a robot-based acoustic detection system that will detect an impulsive noise event, such as a sniper's weapon firing or door slam, and activate a pan-tilt to orient a visible and infrared camera toward the detected sound. Once the cameras are cued to the target, onboard image processing can then track the target and/or transmit the imagery to a remote operator for navigation, situational awareness, and target detection. Such a vehicle can provide reconnaissance, surveillance, and target acquisition for soldiers, law enforcement, and rescue personnel, and remove these people from hazardous environments. ARL's primary robotic platforms contain 16-in. diameter, eight-element acoustic arrays. Additionally, a 9- in. array is being developed in support of DARPA's Tactical Mobile Robot program. The robots have been tested in both urban and open terrain. The current acoustic processing algorithm has been optimized to detect the muzzle blast from a sniper's weapon, and reject many interfering noise sources such as wind gusts, generators, and self-noise. However, other detection algorithms for speech and vehicle detection/tracking are being developed for implementation on this and smaller robotic platforms. The collaboration between two robots, both with known positions and orientations, can provide useful triangulation information for more precise localization of the acoustic events. These robots can be mobile sensor nodes in a larger, more expansive, sensor network that may include stationary ground sensors, UAVs, and other command and control assets. This report will document the performance of the robot's acoustic localization, describe the algorithm, and outline future work.

  14. Effective localized collection and identification of airborne species through electrodynamic precipitation and SERS-based detection

    PubMed Central

    Lin, En-Chiang; Fang, Jun; Park, Se-Chul; Johnson, Forrest W.; Jacobs, Heiko O.

    2013-01-01

    Various nanostructured sensor designs currently aim to achieve or claim single molecular detection by a reduction of the active sensor size. However, a reduction of the sensor size has the negative effect of reducing the capture probability considering the diffusion-based analyte transport commonly used. Here we introduce and apply a localized programmable electrodynamic precipitation concept as an alternative to diffusion. The process provides higher collection rates of airborne species and detection at lower concentration. As an example, we compare an identical nanostructured surfaced-enhanced Raman spectroscopy sensor with and without localized delivery and find that the sensitivity and detection time is improved by at least two orders of magnitudes. Localized collection in an active-matrix array-like fashion is also tested, yielding hybrid molecular arrays on a single chip over a broad range of molecular weights, including small benzenethiol (110.18 Da) and 4-fluorobenzenethiol (128.17 Da), or large macromolecules such as anti-mouse IgG (~150 kDa). PMID:23535657

  15. In vivo detection of GABA in human brain using a localized double-quantum filter technique.

    PubMed

    Keltner, J R; Wald, L L; Frederick, B D; Renshaw, P F

    1997-03-01

    A proton MR spectral editing technique employing a spatially localized, double-quantum filter (DQF) was used to measure gamma-aminobutyric acid (GABA) in the human brain at 1.5 T. The double-quantum method provided robust, single-shot suppression of uncoupled resonances from choline, creatine, and NAA and allowed detection of the gamma CH2 GABA (3.0 ppm) resonance with 30% efficiency. Spatial localization of the GABA measurement was achieved by incorporating PRESS localization within the double-quantum excitation and detection sequence. A calibration technique was developed to adjust the relative phases of the RF pulses to maximize the in vivo double-quantum detection efficiency for an arbitrary voxel location. The sequence efficiency, degree of suppression of uncoupled reasonances, and characterization of the in vivo DQF technique was examined in phantom experiments and in a study of the occipital lobe of 10 normal subjects. The ratio of the 3.0-ppm GABA resonance to the 3.0-ppm creatine resonance was found to be 0.20 +/- 0.05 (SD).

  16. Plasmodium malariae Prevalence and csp Gene Diversity, Kenya, 2014 and 2015

    PubMed Central

    Nguyen, Kristie; Nguyen, Jennifer; Hemming-Schroeder, Elizabeth; Xu, Jiaobao; Etemesi, Harrisone; Githeko, Andrew

    2017-01-01

    In Africa, control programs that target primarily Plasmodium falciparum are inadequate for eliminating malaria. To learn more about prevalence and genetic variability of P. malariae in Africa, we examined blood samples from 663 asymptomatic and 245 symptomatic persons from western Kenya during June–August of 2014 and 2015. P. malariae accounted for 5.3% (35/663) of asymptomatic infections and 3.3% (8/245) of clinical cases. Among asymptomatic persons, 71% (32/45) of P. malariae infections detected by PCR were undetected by microscopy. The low sensitivity of microscopy probably results from the significantly lower parasitemia of P. malariae. Analyses of P. malariae circumsporozoite protein gene sequences revealed high genetic diversity among P. malariae in Africa, but no clear differentiation among geographic populations was observed. Our findings suggest that P. malariae should be included in the malaria elimination strategy in Africa and highlight the need for sensitive and field-applicable methods to identify P. malariae in malaria-endemic areas. PMID:28322694

  17. Plasmodium malariae Prevalence and csp Gene Diversity, Kenya, 2014 and 2015.

    PubMed

    Lo, Eugenia; Nguyen, Kristie; Nguyen, Jennifer; Hemming-Schroeder, Elizabeth; Xu, Jiaobao; Etemesi, Harrisone; Githeko, Andrew; Yan, Guiyun

    2017-04-01

    In Africa, control programs that target primarily Plasmodium falciparum are inadequate for eliminating malaria. To learn more about prevalence and genetic variability of P. malariae in Africa, we examined blood samples from 663 asymptomatic and 245 symptomatic persons from western Kenya during June-August of 2014 and 2015. P. malariae accounted for 5.3% (35/663) of asymptomatic infections and 3.3% (8/245) of clinical cases. Among asymptomatic persons, 71% (32/45) of P. malariae infections detected by PCR were undetected by microscopy. The low sensitivity of microscopy probably results from the significantly lower parasitemia of P. malariae. Analyses of P. malariae circumsporozoite protein gene sequences revealed high genetic diversity among P. malariae in Africa, but no clear differentiation among geographic populations was observed. Our findings suggest that P. malariae should be included in the malaria elimination strategy in Africa and highlight the need for sensitive and field-applicable methods to identify P. malariae in malaria-endemic areas.

  18. Sparsity divergence index based on locally linear embedding for hyperspectral anomaly detection

    NASA Astrophysics Data System (ADS)

    Zhang, Lili; Zhao, Chunhui

    2016-04-01

    Hyperspectral imagery (HSI) has high spectral and spatial resolutions, which are essential for anomaly detection (AD). Many anomaly detectors assume that the spectrum signature of HSI pixels can be modeled with a Gaussian distribution, which is actually not accurate and often leads to many false alarms. Therefore, a sparsity model without any distribution hypothesis is usually employed. Dimensionality reduction (DR) as a preprocessing step for HSI is important. Principal component analysis as a conventional DR method is a linear projection and cannot exploit the nonlinear properties in hyperspectral data, whereas locally linear embedding (LLE) as a local, nonlinear manifold learning algorithm works well for DR of HSI. A modified algorithm of sparsity divergence index based on locally linear embedding (SDI-LLE) is thus proposed. First, kernel collaborative representation detection is adopted to calculate the sparse dictionary matrix of local reconstruction weights in LLE. Then, SDI is obtained both in the spectral and spatial domains, where spatial SDI is computed after DR by LLE. Finally, joint SDI, combining spectral SDI and spatial SDI, is computed, and the optimal SDI is performed for AD. Experimental results demonstrate that the proposed algorithm significantly improves the performance, when compared with its counterparts.

  19. Robust MR spine detection using hierarchical learning and local articulated model.

    PubMed

    Zhan, Yiqiang; Maneesh, Dewan; Harder, Martin; Zhou, Xiang Sean

    2012-01-01

    A clinically acceptable auto-spine detection system, i.e., localization and labeling of vertebrae and inter-vertebral discs, is required to have high robustness, in particular to severe diseases (e.g., scoliosis) and imaging artifacts (e.g. metal artifacts in MR). Our method aims to achieve this goal with two novel components. First, instead of treating vertebrae/discs as either repetitive components or completely independent entities, we emulate a radiologist and use a hierarchial strategy to learn detectors dedicated to anchor (distinctive) vertebrae, bundle (non-distinctive) vertebrae and inter-vertebral discs, respectively. At run-time, anchor vertebrae are detected concurrently to provide redundant and distributed appearance cues robust to local imaging artifacts. Bundle vertebrae detectors provide candidates of vertebrae with subtle appearance differences, whose labels are mutually determined by anchor vertebrae to gain additional robustness. Disc locations are derived from a cloud of responses from disc detectors, which is robust to sporadic voxel-level errors. Second, owing to the non-rigidness of spine anatomies, we employ a local articulated model to effectively model the spatial relations across vertebrae and discs. The local articulated model fuses appearance cues from different detectors in a way that is robust to abnormal spine geometry resulting from severe diseases. Our method is validated by 300 MR spine scout scans and exhibits robust performance, especially to cases with severe diseases and imaging artifacts.

  20. Space-time clustering of childhood malaria at the household level: a dynamic cohort in a Mali village

    PubMed Central

    Gaudart, Jean; Poudiougou, Belco; Dicko, Alassane; Ranque, Stéphane; Toure, Ousmane; Sagara, Issaka; Diallo, Mouctar; Diawara, Sory; Ouattara, Amed; Diakite, Mahamadou; Doumbo, Ogobara K

    2006-01-01

    Background Spatial and temporal heterogeneities in the risk of malaria have led the WHO to recommend fine-scale stratification of the epidemiological situation, making it possible to set up actions and clinical or basic researches targeting high-risk zones. Before initiating such studies it is necessary to define local patterns of malaria transmission and infection (in time and in space) in order to facilitate selection of the appropriate study population and the intervention allocation. The aim of this study was to identify, spatially and temporally, high-risk zones of malaria, at the household level (resolution of 1 to 3 m). Methods This study took place in a Malian village with hyperendemic seasonal transmission as part of Mali-Tulane Tropical Medicine Research Center (NIAID/NIH). The study design was a dynamic cohort (22 surveys, from June 1996 to June 2001) on about 1300 children (<12 years) distributed between 173 households localized by GPS. We used the computed parasitological data to analyzed levels of Plasmodium falciparum, P. malariae and P. ovale infection and P. falciparum gametocyte carriage by means of time series and Kulldorff's scan statistic for space-time cluster detection. Results The time series analysis determined that malaria parasitemia (primarily P. falciparum) was persistently present throughout the population with the expected seasonal variability pattern and a downward temporal trend. We identified six high-risk clusters of P. falciparum infection, some of which persisted despite an overall tendency towards a decrease in risk. The first high-risk cluster of P. falciparum infection (rate ratio = 14.161) was detected from September 1996 to October 1996, in the north of the village. Conclusion This study showed that, although infection proportions tended to decrease, high-risk zones persisted in the village particularly near temporal backwaters. Analysis of this heterogeneity at the household scale by GIS methods lead to target preventive

  1. Longitudinal Visuomotor Development in a Malaria Endemic Area: Cerebral Malaria and Beyond

    PubMed Central

    MacCormick, Ian J. C.; Mbale, Emme; Malewa, Macpherson; Czanner, Gabriela; Harding, Simon P.

    2016-01-01

    Paediatric cerebral malaria is the most serious complication of Plasmodium falciparum infection. While the majority recover, long-term cognitive impairment has been highlighted as a significant and neglected problem. Persistent or serious deficits in processes such as attention or behavioural inhibition should be manifest in changes to performance on oculomotor tasks. Therefore we investigated the impact of cerebral malaria on the development of reflexive pro-saccades and antisaccades. In a longitudinal study, 47 children previously admitted with retinopathy-confirmed cerebral malaria (mean age at admission 54 months), were compared with 37 local healthy controls (mean ages at first study visit 117 and 110 months respectively). In each of three or four test sessions, over a period of up to 32 months, participants completed 100 prosaccade tasks and 100 antisaccade tasks. Eye movements were recorded using infrared reflectance oculography; prosaccade, correct antisaccade and error prosaccade latency, and antisaccade directional error rate were calculated. Hierarchical linear modelling was used to investigate the effect of age and the influence of cerebral malaria on these parameters. Data were also collected from an independent, older group (mean age 183 months) of 37 local healthy participants in a separate cross-sectional study. Longitudinal data exhibited the expected decrease in latency with age for all saccade types, and a decrease in the antisaccade directional error rate. Hierarchical linear modelling confirmed that age had a statistically significant effect on all parameters (p< = 0.001). However, there were no statistically significant differences between the cerebral malaria and control groups. Combining groups, comparison with the literature demonstrated that antisaccade directional error rate for the Malawi sample was significantly higher than expected, while latencies for all saccade types were indistinguishable from published. The high directional error

  2. Longitudinal Visuomotor Development in a Malaria Endemic Area: Cerebral Malaria and Beyond.

    PubMed

    Knox, Paul C; MacCormick, Ian J C; Mbale, Emme; Malewa, Macpherson; Czanner, Gabriela; Harding, Simon P

    2016-01-01

    Paediatric cerebral malaria is the most serious complication of Plasmodium falciparum infection. While the majority recover, long-term cognitive impairment has been highlighted as a significant and neglected problem. Persistent or serious deficits in processes such as attention or behavioural inhibition should be manifest in changes to performance on oculomotor tasks. Therefore we investigated the impact of cerebral malaria on the development of reflexive pro-saccades and antisaccades. In a longitudinal study, 47 children previously admitted with retinopathy-confirmed cerebral malaria (mean age at admission 54 months), were compared with 37 local healthy controls (mean ages at first study visit 117 and 110 months respectively). In each of three or four test sessions, over a period of up to 32 months, participants completed 100 prosaccade tasks and 100 antisaccade tasks. Eye movements were recorded using infrared reflectance oculography; prosaccade, correct antisaccade and error prosaccade latency, and antisaccade directional error rate were calculated. Hierarchical linear modelling was used to investigate the effect of age and the influence of cerebral malaria on these parameters. Data were also collected from an independent, older group (mean age 183 months) of 37 local healthy participants in a separate cross-sectional study. Longitudinal data exhibited the expected decrease in latency with age for all saccade types, and a decrease in the antisaccade directional error rate. Hierarchical linear modelling confirmed that age had a statistically significant effect on all parameters (p< = 0.001). However, there were no statistically significant differences between the cerebral malaria and control groups. Combining groups, comparison with the literature demonstrated that antisaccade directional error rate for the Malawi sample was significantly higher than expected, while latencies for all saccade types were indistinguishable from published. The high directional error

  3. Coffee rings as low-resource diagnostics: detection of the malaria biomarker Plasmodium falciparum histidine-rich protein-II using a surface-coupled ring of Ni(II)NTA gold-plated polystyrene particles.

    PubMed

    Gulka, Christopher P; Swartz, Joshua D; Trantum, Joshua R; Davis, Keersten M; Peak, Corey M; Denton, Alexander J; Haselton, Frederick R; Wright, David W

    2014-05-14

    We report a novel, low-resource malaria diagnostic platform inspired by the coffee ring phenomenon, selective for Plasmodium falciparum histidine-rich protein-II (PfHRP-II), a biomarker indicative of the P. falciparum parasite strain. In this diagnostic design, a recombinant HRP-II (rcHRP-II) biomarker is sandwiched between 1 μm Ni(II)nitrilotriacetic acid (NTA) gold-plated polystyrene microspheres (AuPS) and Ni(II)NTA-functionalized glass. After rcHRP-II malaria biomarkers had reacted with Ni(II)NTA-functionalized particles, a 1 μL volume of the particle-protein conjugate solution is deposited onto a functionalized glass slide. Drop evaporation produces the radial flow characteristic of coffee ring formation, and particle-protein conjugates are transported toward the drop edge, where, in the presence of rcHRP-II, particles bind to the Ni(II)NTA-functionalized glass surface. After evaporation, a wash with deionized water removes nonspecifically bound materials while maintaining the integrity of the surface-coupled ring produced by the presence of the protein biomarker. The dynamic range of this design was found to span 3 orders of magnitude, and rings are visible with the naked eye at protein concentrations as low as 10 pM, 1 order of magnitude below the 100 pM PfHRP-II threshold recommended by the World Health Organization. Key enabling features of this design are the inert and robust gold nanoshell to reduce nonspecific interactions on the particle surface, inclusion of a water wash step after drop evaporation to reduce nonspecific binding to the glass, a large diameter particle to project a large two-dimensional viewable area after ring formation, and a low particle density to favor radial flow toward the drop edge and reduce vertical settling to the glass surface in the center of the drop. This robust, antibody-free assay offers a simple user interface and clinically relevant limits of biomarker detection, two critical features required for low

  4. The treatment of malaria.

    PubMed

    White, N J

    1996-09-12

    Increasing drug resistance in Plasmodium falciparum and a resurgence of malaria in tropical areas have effected a change in treatment of malaria in the last two decades. Symptoms of malaria are fever, chills, headache, and malaise. The prognosis worsens as the parasite counts, counts of mature parasites, and counts of neutrophils containing pigment increase. Treatment depends on severity, age of patient, degree of background immunity, likely pattern of susceptibility to antimalarial drugs, and the cost and availability of drugs. Chloroquine should be used for P. vivax, P. malariae, and P. ovale. P. vivax has shown high resistance to chloroquine in Oceania, however. Primaquine may be needed to treat P. vivax and P. ovale to rid the body of hypnozoites that survive in the liver. Chloroquine can treat P. falciparum infections acquired in North Africa, Central America north of the Panama Canal, Haiti, or the Middle East but not in most of Africa and some parts of Asia and South America. In areas of low grade resistance to chloroquine, amodiaquine can be used to effectively treat falciparum malaria. A combination of sulfadoxine-pyrimethamine is responsive to falciparum infections with high grade resistance to chloroquine. Mefloquine, halofantrine, or quinine with tetracycline can be used to treat multidrug-resistant P. falciparum. Derivatives of artemisinin obtained from qinghao or sweet wormwood developed as pharmaceuticals in China are the most rapidly acting of all antimalarial drugs. Children tend to tolerate antimalarial drugs well. Children who weigh less than 15 kg should not be given mefloquine. Health workers should not prescribe primaquine to pregnant women or newborns due to the risk of hemolysis. Chloroquine, sulfadoxine-pyrimethamine, quinine, and quinidine can be safely given in therapeutic doses throughout pregnancy. Clinical manifestations of severe malaria are hypoglycemia, convulsions, severe anemia, acute renal failure, jaundice, pulmonary edema

  5. [Malaria in the Americas].

    PubMed

    Carme, B; Venturin, C

    1999-01-01

    In 1996, malaria involving Plasmodium vivax, Plasmodium falciparum, and, to a lesser extent, Plasmodium malariae was endemic in 21 countries in the Americas. The Amazon river basin and bordering areas including the Guyanas were the most affected zones. Until the mid 1970s, endemic malaria appeared to be under control. However in the ensuing 15 year period, the situation deteriorated drastically. Although trends varied depending on location, aggregate indexes indicated a twofold increase with recrudescence in previously settled areas and emergence in newly populated zones. Since 1990, the situation has worsened further in some areas where increased incidences have been associated with a high levels of drug-resistant Plasmodium falciparum. However this species remains in minority except in the Guyanas where the highest annual incidences (100 to 500 cases per 1000) and the most drug-resistant Plasmodium have been reported. The causes underlying this deterioration are numerous and complex. In regions naturally prone to transmission of the disease, outbreaks have been intensified by unrestrained settlement. The resulting deforestation has created new breeding areas for Anopheles darlingi, the main vector of malaria in the Americas. Migration of poor populations to newly opened farming and mining areas has created highly exposed areas for malaria infection. Implementation of adequate medical care and prevention measures has been hindered by a lack of money and sociopolitical unrest. Climatic phenomenon related the El Nino have also been favorable to the return of malaria to the region. Except with regard to financial resources and political unrest, the same risk factors for malaria are present in French Guiana.

  6. SuBSENSE: a universal change detection method with local adaptive sensitivity.

    PubMed

    St-Charles, Pierre-Luc; Bilodeau, Guillaume-Alexandre; Bergevin, Robert

    2015-01-01

    Foreground/background segmentation via change detection in video sequences is often used as a stepping stone in high-level analytics and applications. Despite the wide variety of methods that have been proposed for this problem, none has been able to fully address the complex nature of dynamic scenes in real surveillance tasks. In this paper, we present a universal pixel-level segmentation method that relies on spatiotemporal binary features as well as color information to detect changes. This allows camouflaged foreground objects to be detected more easily while most illumination variations are ignored. Besides, instead of using manually set, frame-wide constants to dictate model sensitivity and adaptation speed, we use pixel-level feedback loops to dynamically adjust our method's internal parameters without user intervention. These adjustments are based on the continuous monitoring of model fidelity and local segmentation noise levels. This new approach enables us to outperform all 32 previously tested state-of-the-art methods on the 2012 and 2014 versions of the ChangeDetection.net dataset in terms of overall F-Measure. The use of local binary image descriptors for pixel-level modeling also facilitates high-speed parallel implementations: our own version, which used no low-level or architecture-specific instruction, reached real-time processing speed on a midlevel desktop CPU. A complete C++ implementation based on OpenCV is available online.

  7. Simultaneous Life Detection and Localization Using a Wideband Chaotic Signal with an Embedded Tone.

    PubMed

    Liu, Li; Guo, Chaoyi; Li, Jingxia; Xu, Hang; Zhang, Jianguo; Wang, Bingjie

    2016-11-06

    A hybrid life detection radar system which transmits a wideband chaotic signal containing an embedded single-tone is proposed. The chaotic signal is used for target localization by the time-domain correlation method and synthetic aperture technique, and the single-tone signal is used to measure the frequencies of breathing and heartbeat based on an on-chip split-ring integrated sensor and Michelson interference principle. Experimental results in free space and in through-wall scenarios demonstrate that the system can realize human detection and localization simultaneously with high range resolution, high sensitivity, and large dynamic range without complex signal processing. The range resolution is about 10 cm, and the dynamic range is 35 dB for the respiration signal detection and 25 dB for the heartbeat signal detection. Due to its good immunity to interference/jamming and high spectrum efficiency, the proposed system is suitable for post-disaster rescue, elder/infant/patient vitality monitoring, and anti-terrorism enforcement applications.

  8. An adaptive locally linear embedding manifold learning approach for hyperspectral target detection

    NASA Astrophysics Data System (ADS)

    Ziemann, Amanda K.; Messinger, David W.

    2015-05-01

    Algorithms for spectral analysis commonly use parametric or linear models of the data. Research has shown, however, that hyperspectral data -- particularly in materially cluttered scenes -- are not always well-modeled by statistical or linear methods. Here, we propose an approach to hyperspectral target detection that is based on a graph theory model of the data and a manifold learning transformation. An adaptive nearest neighbor (ANN) graph is built on the data, and then used to implement an adaptive version of locally linear embedding (LLE). We artificially induce a target manifold and incorporate it into the adaptive LLE transformation. The artificial target manifold helps to guide the separation of the target data from the background data in the new, transformed manifold coordinates. Then, target detection is performed in the manifold space using Spectral Angle Mapper. This methodology is an improvement over previous iterations of this approach due to the incorporation of ANN, the artificial target manifold, and the choice of detector in the transformed space. We implement our approach in a spatially local way: the image is delineated into square tiles, and the detection maps are normalized across the entire image. Target detection results will be shown using laboratory-measured and scene-derived target data from the SHARE 2012 collect.

  9. Simultaneous Life Detection and Localization Using a Wideband Chaotic Signal with an Embedded Tone

    PubMed Central

    Liu, Li; Guo, Chaoyi; Li, Jingxia; Xu, Hang; Zhang, Jianguo; Wang, Bingjie

    2016-01-01

    A hybrid life detection radar system which transmits a wideband chaotic signal containing an embedded single-tone is proposed. The chaotic signal is used for target localization by the time-domain correlation method and synthetic aperture technique, and the single-tone signal is used to measure the frequencies of breathing and heartbeat based on an on-chip split-ring integrated sensor and Michelson interference principle. Experimental results in free space and in through-wall scenarios demonstrate that the system can realize human detection and localization simultaneously with high range resolution, high sensitivity, and large dynamic range without complex signal processing. The range resolution is about 10 cm, and the dynamic range is 35 dB for the respiration signal detection and 25 dB for the heartbeat signal detection. Due to its good immunity to interference/jamming and high spectrum efficiency, the proposed system is suitable for post-disaster rescue, elder/infant/patient vitality monitoring, and anti-terrorism enforcement applications. PMID:27827976

  10. In vivo microscopy of hemozoin: towards a needle free diagnostic for malaria

    PubMed Central

    Burnett, Jennifer L.; Carns, Jennifer L.; Richards-Kortum, Rebecca

    2015-01-01

    Clinical diagnosis of malaria suffers from poor specificity leading to overtreatment with antimalarial medications. Alternatives, like blood smear microscopy or antigen-based tests, require a blood sample. We investigate in vivo microscopy as a needle-free malaria diagnostic. Two optical signatures, birefringence and absorbance, of the endogenous malaria by-product hemozoin were evaluated as in vivo optical biomarkers. Hemozoin birefringence was difficult to detect in highly scattering tissue; however, hemozoin absorbance was observed in increasingly complex biological environments and detectable over a clinically-relevant range of parasitemia in vivo in a P. yoelii-infected mouse model of malaria. PMID:26417515

  11. Potential impact of global climate change on malaria risk

    SciTech Connect

    Martens, W.J.M.; Rotmans, J. |; Niessen, L.W.; Jetten, T.H.; McMichael, A.J.

    1995-05-01

    The biological activity and geographic distribution of the malarial parasite and its vector are sensitive to climatic influences, especially temperature and precipitation. We have incorporated General Circulation Model-based scenarios of anthropogenic global climate change in an integrated linked-system model for predicting changes in malaria epidemic potential in the next century. The concept of the disability-adjusted life years is included to arrive at a single measure of the effect of anthropogenic climate change on the health impact of malaria. Assessment of the potential impact of global climate change on the incidence of malaria suggests a widespread increase of risk due to expansion of the areas suitable for malaria transmission. This predicted increase is most pronounced at the borders of endemic malaria areas and at higher altitudes within malarial areas. The incidence of infection is sensitive to climate changes in areas of Southeast Asia, South America, and parts of Africa where the disease is less endemic; in these regions the numbers of years of healthy life lost may increase significantly. However, the simulated changes in malaria risk must be interpreted on the basis of local environmental conditions, the effects of socioeconomic developments, and malaria control programs or capabilities. 33 refs., 5 figs., 1 tab.

  12. Malaria Ecology, Disease Burden and Global Climate Change

    NASA Astrophysics Data System (ADS)

    Mccord, G. C.

    2014-12-01

    Malaria has afflicted human society for over 2 million years, and remains one of the great killer diseases today. The disease is the fourth leading cause of death for children under five in low income countries (after neonatal disorders, diarrhea, and pneumonia) and is responsible for at least one in every five child deaths in sub-Saharan Africa. It kills up to 3 million people a year, though in recent years scale up of anti-malaria efforts in Africa may have brought deaths to below 1 million. Malaria is highly conditioned by ecology, because of which climate change is likely to change the local dynamics of the disease through changes in ambient temperature and precipitation. To assess the potential implications of climate change for the malaria burden, this paper employs a Malaria Ecology Index from the epidemiology literature, relates it to malaria incidence and mortality using global country-level data , and then draws implications for 2100 by extrapolating the index using several general circulation model (GCM) predictions of temperature and precipitation. The results highlight the climate change driven increase in the basic reproduction number of the disease and the resulting complications for further gains in elimination. For illustrative purposes, I report the change in malaria incidence and mortality if climate change were to happen immediately under current technology and public health efforts.

  13. Mass drug administration for malaria

    PubMed Central

    Poirot, Eugenie; Skarbinski, Jacek; Sinclair, David; Kachur, S Patrick; Slutsker, Laurence; Hwang, Jimee

    2013-01-01

    first month post-MDA, the single cluster-randomized trial from the Gambia in 1999 found no significant difference in parasite prevalence (one study, low quality evidence). However, prevalence was much lower during the MDA programmes in three non-randomized controlled studies conducted in the 1960s and 1970s (RR 0.17, 95% CI 0.11 to 0.27, three studies, moderate quality evidence), and within one month of MDA in four uncontrolled before-and-after studies (RR 0.37, 95% CI 0.28 to 0.49, four studies,low quality evidence). Four trials reported changes in prevalence beyond three months. In the Gambia, the single cluster-randomized trial found no difference at five months (one trial, moderate quality evidence). The three uncontrolled before-and-after studies had mixed findings with large studies from Palestine and Cambodia showing sustained reductions at four months and 12 months, respectively, and a small study from Malaysia showing no difference after four to six months of follow-up (three studies,low quality evidence). 8-aminoquinolines We found no studies directly comparing MDA regimens that included 8-aminoquinolines with regimens that did not. In a crude subgroup analysis with a limited number of studies, we were unable to detect any evidence of additional benefit of primaquine in moderate- and high-transmission settings. Plasmodium species In studies that reported species-specific outcomes, the same interventions resulted in a larger impact on Plasmodium falciparum compared to P. vivax. Authors' conclusions MDA appears to reduce substantially the initial risk of malaria parasitaemia. However, few studies showed sustained impact beyond six months post-MDA, and those that did were conducted on small islands or in highland settings. To assess whether there is an impact of MDA on malaria transmission in the longer term requires more quasi experimental studies with the intention of elimination, especially in low- and moderate-transmission settings. These studies need to

  14. Risk factors for malaria in UK travellers.

    PubMed

    Moore, David A; Grant, Alison D; Armstrong, Margaret; Stümpfle, Richard; Behrens, Ron H

    2004-01-01

    After observing an apparent increase in severe falciparum malaria among travellers returning from The Gambia to the United Kingdom (UK) in the last quarter of 2000, we conducted a case-control study to investigate risk factors for malaria. The study participants had visited The Gambia between 1 September and 31 December 2000, travelling with the largest UK tour operator serving this destination. The main outcome measures were risk factors associated with malaria. Forty-six cases and 557 controls were studied. Eighty-seven percent of all participants reported antimalarial use (41% chloroquine/proguanil, 31% mefloquine). On univariate analysis the strongest risk factors for disease were: early calendar period of visit, longer duration of stay, non-use of antimalarial prophylaxis, non-use of mefloquine, lack of room air-conditioning, less use of insect repellent, prior visit to another malarial area and accommodation in 'hotel X'. After adjustment in multivariate analysis, use of mefloquine remained strongly protective (odds ratios, OR 0.13 [95% confidence intervals, 95% CI 0.04-0.40]), and the strongest independent risk factors for malaria were early calendar period (OR 5.19 [2.35-11.45] for 1 September to 9 November 2000 versus 10 November to 31 December 2000), prior visit to another malarial area (OR 3.27 [1.41-7.56]), main accommodation in 'hotel X' (OR 3.24 [1.51-6.97]) and duration of stay (OR 2.05 per extra week [1.42-2.95]). Neither any use, nor > 90% adherence to chloroquine/proguanil were protective (adjusted OR for any use 0.57 [0.27-1.21], P = 0.14). We concluded mefloquine use was strongly protective against malaria (87% protective efficacy), whereas chloroquine/proguanil, which is no longer recommended but remains widely used, was less than half as effective (43% protective efficacy). Waning efficacy of chloroquine/proguanil may have contributed to the observed increase in malaria among travellers to The Gambia in 2000. Local factors may also influence

  15. Detection of linear features using a localized radon transform with a wavelet filter

    SciTech Connect

    Warrick, A L; Delaney, P A

    1999-12-13

    One problem of interest to the oceanic engineering community is the detection and enhancement of internal wakes in open water synthetic aperture radar (SAR) images. Internal wakes, which occur when a ship travels in a stratified medium, have a V shape extending from the ship, and a chirp-like feature across each arm. The Radon transform has been applied to the detection and the enhancement problems in internal wake images to account for the linear features while the wavelet transform has been applied to the enhancement problem in internal wake images to account for the chirp-like features. In this paper, a new transform, a localized Radon transform with a wavelet filter (LRTWF), is developed which accounts for both the linear and the chirp-like features of the internal wake. This transform is then incorporated into optimal and sub-optimal detection schemes for images (with these features) which are contaminated by additive Gaussian noise.

  16. Detecting continuous spontaneous localization with charged bodies in a Paul trap

    NASA Astrophysics Data System (ADS)

    Li, Ying; Steane, Andrew M.; Bedingham, Daniel; Briggs, G. Andrew D.

    2017-03-01

    Continuous spontaneous localization (CSL) is a model that captures the effects of a class of extensions to quantum theory which are expected to result from quantum gravity and is such that wave-function collapse is a physical process. The rate of such a process could be very much lower than the upper bounds set by searches to date and yet still modify greatly the interpretation of quantum mechanics and solve the quantum measurement problem. Consequently experiments are sought to explore this. We describe an experiment that has the potential to extend sensitivity to CSL by many orders of magnitude. The method is to detect heating of the motion of charged macroscopic objects confined in a Paul trap. We discuss the detection and the chief noise sources. We find that CSL with standard parameters could be observed using a vibration-isolated ion trap of size 1 cm at ultralow pressure with optical interferometric detection.

  17. Real-time detection of generic objects using objectness estimation and locally adaptive regression kernels matching

    NASA Astrophysics Data System (ADS)

    Zheng, Zhihui; Gao, Lei; Xiao, Liping; Zhou, Bin; Gao, Shibo

    2015-12-01

    Our purpose is to develop a detection algorithm capable of searching for generic interest objects in real time without large training sets and long-time training stages. Instead of the classical sliding window object detection paradigm, we employ an objectness measure to produce a small set of candidate windows efficiently using Binarized Normed Gradients and a Laplacian of Gaussian-like filter. We then extract Locally Adaptive Regression Kernels (LARKs) as descriptors both from a model image and the candidate windows which measure the likeness of a pixel to its surroundings. Using a matrix cosine similarity measure, the algorithm yields a scalar resemblance map, indicating the likelihood of similarity between the model and the candidate windows. By employing nonparametric significance tests and non-maxima suppression, we detect the presence of objects similar to the given model. Experiments show that the proposed detection paradigm can automatically detect the presence, the number, as well as location of similar objects to the given model. The high quality and efficiency of our method make it suitable for real time multi-category object detection applications.

  18. Outlier detection for particle image velocimetry data using a locally estimated noise variance

    NASA Astrophysics Data System (ADS)

    Lee, Yong; Yang, Hua; Yin, ZhouPing

    2017-03-01

    This work describes an adaptive spatial variable threshold outlier detection algorithm for raw gridded particle image velocimetry data using a locally estimated noise variance. This method is an iterative procedure, and each iteration is composed of a reference vector field reconstruction step and an outlier detection step. We construct the reference vector field using a weighted adaptive smoothing method (Garcia 2010 Comput. Stat. Data Anal. 54 1167-78), and the weights are determined in the outlier detection step using a modified outlier detector (Ma et al 2014 IEEE Trans. Image Process. 23 1706-21). A hard decision on the final weights of the iteration can produce outlier labels of the field. The technical contribution is that the spatial variable threshold motivation is embedded in the modified outlier detector with a locally estimated noise variance in an iterative framework for the first time. It turns out that a spatial variable threshold is preferable to a single spatial constant threshold in complicated flows such as vortex flows or turbulent flows. Synthetic cellular vortical flows with simulated scattered or clustered outliers are adopted to evaluate the performance of our proposed method in comparison with popular validation approaches. This method also turns out to be beneficial in a real PIV measurement of turbulent flow. The experimental results demonstrated that the proposed method yields the competitive performance in terms of outlier under-detection count and over-detection count. In addition, the outlier detection method is computational efficient and adaptive, requires no user-defined parameters, and corresponding implementations are also provided in supplementary materials.

  19. Application of loop analysis for evaluation of malaria control interventions

    PubMed Central

    2014-01-01

    Background Despite continuous efforts and recent rapid expansion in the financing and implementation of malaria control interventions, malaria still remains one of the most devastating global health issues. Even in countries that have been successful in reducing the incidence of malaria, malaria control is becoming more challenging because of the changing epidemiology of malaria and waning community participation in control interventions. In order to improve the effectiveness of interventions and to promote community understanding of the necessity of continued control efforts, there is an urgent need to develop new methodologies that examine the mechanisms by which community-based malaria interventions could reduce local malaria incidence. Methods This study demonstrated how the impact of community-based malaria control interventions on malaria incidence can be examined in complex systems by qualitative analysis combined with an extensive review of literature. First, sign digraphs were developed through loop analysis to analyse seven interventions: source reduction, insecticide/larvicide use, biological control, treatment with anti-malarials, insecticide-treated mosquito net/long-lasting insecticidal net, non-chemical personal protection measures, and educational intervention. Then, for each intervention, the sign digraphs and literature review were combined to analyse a variety of pathways through which the intervention can influence local malaria incidence as well as interactions between variables involved in the system. Through loop analysis it is possible to see whether increases in one variable qualitatively increases or decreases other variables or leaves them unchanged and the net effect of multiple, interacting variables. Results Qualitative analysis, specifically loop analysis, can be a useful tool to examine the impact of community-based malaria control interventions. Without relying on numerical data, the analysis was able to describe pathways through

  20. A family of locally constrained CCA models for detecting activation patterns in fMRI.

    PubMed

    Zhuang, Xiaowei; Yang, Zhengshi; Curran, Tim; Byrd, Richard; Nandy, Rajesh; Cordes, Dietmar

    2017-04-01

    Canonical correlation analysis (CCA) has been used in Functional Magnetic Resonance Imaging (fMRI) for improved detection of activation by incorporating time series from multiple voxels in a local neighborhood. To improve the specificity of local CCA methods, spatial constraints were previously proposed. In this study, constraints are generalized by introducing a family model of spatial constraints for CCA to further increase both sensitivity and specificity in fMRI activation detection. The proposed locally-constrained CCA (cCCA) model is formulated in terms of a multivariate constrained optimization problem and solved efficiently with numerical optimization techniques. To evaluate the performance of this cCCA model, simulated data are generated with a Signal-To-Noise Ratio of 0.25, which is realistic to the noise level contained in episodic memory fMRI data. Receiver operating characteristic (ROC) methods are used to compare the performance of different models. The cCCA model with optimum parameters (called optimum-cCCA) obtains the largest area under the ROC curve. Furthermore, a novel validation method is proposed to validate the selected optimum-cCCA parameters based on ROC from simulated data and real fMRI data. Results for optimum-cCCA are then compared with conventional fMRI analysis methods using data from an episodic memory task. Wavelet-resampled resting-state data are used to obtain the null distribution of activation. For simulated data, accuracy in detecting activation increases for the optimum-cCCA model by about 43% as compared to the single voxel analysis with comparable Gaussian smoothing. Results from the real fMRI data set indicate a significant increase in activation detection, particularly in hippocampus, para-hippocampal area and nearby medial temporal lobe regions with the proposed method.

  1. Selective Intermittent Preventive Treatment of Vivax Malaria: Reduction of Malaria Incidence in an Open Cohort Study in Brazilian Amazon

    PubMed Central

    Gil, Luiz Herman Soares; de Lima, Alzemar Alves; Freitag, Elci Marlei; dos Santos, Tatiana Marcondes; do Nascimento Filha, Maria Teixeira; dos Santos Júnior, Alcides Procópio Justiniano; da Silva, Josiane Mendes; Rodrigues, Aline de Freitas; Tada, Mauro Shugiro; Fontes, Cor Jesus Fernandes; Pereira da Silva, Luiz Hildebrando

    2013-01-01

    In children, the Intermittent Preventive Treatment (IPTc), currently called Seasonal Malaria Chemoprevention (SMC), was considered effective on malaria control due to the reduction of its incidence in Papua New Guinea and in some areas with seasonal malaria in Africa. However, the IPT has not been indicated because of its association with drug resistance and for hindering natural immunity development. Thus, we evaluated the alternative IPT impact on malaria incidence in three riverside communities on Madeira River, in the municipality of Porto Velho, RO. We denominate this scheme Selective Intermittent Preventive Treatment (SIPT). The SIPT consists in a weekly dose of two 150 mg chloroquine tablets for 12 weeks, for adults, and an equivalent dose for children, after complete supervised treatment for P. vivax infection. This scheme is recommend by Brazilian Health Ministry to avoid frequent relapses. The clinic parasitological and epidemiological surveillance showed a significant reduction on vivax malaria incidence. The results showed a reduction on relapses and recurrence of malaria after SIPT implementation. The SIPT can be effective on vivax malaria control in localities with high transmission risk in the Brazilian Amazon. PMID:23577276

  2. The drug sensitivity and transmission dynamics of human malaria on Nias Island, North Sumatra, Indonesia.

    PubMed

    Fryauff, D J; Leksana, B; Masbar, S; Wiady, I; Sismadi, P; Susanti, A I; Nagesha, H S; Syafruddin; Atmosoedjono, S; Bangs, M J; Baird, J K

    2002-07-01

    Nias Island, off the north-western coast of Sumatra, Indonesia, was one of the first locations in which chloroquine-resistant Plasmodium vivax malaria was reported. This resistance is of particular concern because its ancient megalithic culture and the outstanding surfing conditions make the island a popular tourist destination. International travel to and from the island could rapidly spread chloroquine-resistant strains of P. vivax across the planet. The threat posed by such strains, locally and internationally, has led to the routine and periodic re-assessment of the efficacy of antimalarial drugs and transmission potential on the island. Active case detection identified malaria in 124 (17%) of 710 local residents whereas passive case detection, at the central health clinic, confirmed malaria in 77 (44%) of 173 cases of presumed 'clinical malaria'. Informed consenting volunteers who had malarial parasitaemias were treated, according to the Indonesian Ministry of Health's recommendations, with sulfadoxine-pyrimethamine (SP) on day 0 (for P. falciparum) or with chloroquine (CQ) on days 0, 1 and 2 (for P. vivax). Each volunteer was then monitored for clinical and parasite response until day 28. Recurrent parasitaemia by day 28 treatment was seen in 29 (83%) of the 35 P. falciparum cases given SP (14, 11 and four cases showing RI, RII and RIII resistance, respectively). Recurrent parasitaemia was also observed, between day 11 and day 21, in six (21%) of the 28 P. vivax cases given CQ. Although the results of quantitative analysis confirmed only low prevalences of CQ-resistant P. vivax malaria, the prevalence of SP resistance among the P. falciparum cases was among the highest seen in Indonesia. When the parasites present in the volunteers with P. falciparum infections were genotyped, mutations associated with pyrimethamine resistance were found at high frequency in the dhfr gene but there was no evidence of selection for sulfadoxine resistance in the dhps gene

  3. Comparative evaluation of two rapid field tests for malaria diagnosis: Partec Rapid Malaria Test® and Binax Now® Malaria Rapid Diagnostic Test

    PubMed Central

    2011-01-01

    Background About 90% of all malaria deaths in sub-Saharan Africa occur in children under five years. Fast and reliable diagnosis of malaria requires confirmation of the presence of malaria parasites in the blood of patients with fever or history suggestive of malaria; hence a prompt and accurate diagnosis of malaria is the key to effective disease management. Confirmation of malaria infection requires the availability of a rapid, sensitive, and specific testing at an affordable cost. We compared two recent methods (the novel Partec Rapid Malaria Test® (PT) and the Binax Now® Malaria Rapid Diagnostic Test (BN RDT) with the conventional Giemsa stain microscopy (GM) for the diagnosis of malaria among children in a clinical laboratory of a hospital in a rural endemic area of Ghana. Methods Blood samples were collected from 263 children admitted with fever or a history of fever to the pediatric clinic of the Agogo Presbyterian Hospital. The three different test methods PT, BN RDT and GM were performed independently by well trained and competent laboratory staff to assess the presence of malaria parasites. Results were analyzed and compared using GM as the reference standard. Results In 107 (40.7%) of 263 study participants, Plasmodium sp. was detected by GM. PT and BN RDT showed positive results in 111 (42.2%) and 114 (43.4%), respectively. Compared to GM reference standard, the sensitivities of the PT and BN RDT were 100% (95% CI: 96.6-100) and 97.2% (95% CI: 92.0-99.4), respectively, specificities were 97.4% (95% CI: 93.6-99.3) and 93.6% (95% CI: 88.5-96.9), respectively. There was a strong agreement (kappa) between the applied test methods (GM vs PT: 0.97; p < 0.001 and GM vs BN RDT: 0.90; p < 0.001). The average turnaround time per tests was 17 minutes. Conclusion In this study two rapid malaria tests, PT and BN RDT, demonstrated a good quality of their performance compared to conventional GM. Both methods require little training, have short turnaround times, are

  4. [Malaria cases in Malatya during the past seven years].

    PubMed

    Karaman, Ulkü; Atambay, Metin; Yaşar, Safa; Colak, Cemil; Miman, Ozlem; Daldal, Nilgün

    2007-01-01

    Malaria can be seen in every region inhabited by human blood-sucking Anopheles and species of disease-causing Plasmodium. Since the region is on the crossroads of other cities where malaria is more widespread and it has a population of seasonal workers and an increasing number of tourists during the summer, additional imported cases may also be detected in the Malatya region. The aim of this study was to determine the state of malaria for the past seven years in Malatya. According to the records of the Malaria Control Unit of the Health Directorate of the Malatya province, 189 positive patients were reported during the seven years from 1999-2005. Of these cases, 186 (98.4%) were P. vivax, while 3 (1.6%) were imported cases of P. falciparum malaria. The rate of positivity was found to be 58.2% in male patients and 41.8% in female patients. Consequently, malaria can be said to persist as a health problem in Malatya region. It was concluded that people in the region should be informed about malaria and the ways to protect themselves.

  5. [Malaria in mangrove areas of the Saloum delta (Senegal)].

    PubMed

    Diop, Abdoulaye; Konate, Lassana; Molez, Jean-François; Diouf, Malick; Gaye, Oumar; Fontenille, Didier; Diagne, Moussa; Faye, Ousmane

    2006-01-01

    epidemics. It is therefore important to set up a functional system of epidemiological monitoring to detect any malaria outbreaks.

  6. Absence of detectable transgenes in local landraces of maize in Oaxaca, Mexico (2003-2004).

    PubMed

    Ortiz-García, S; Ezcurra, E; Schoel, B; Acevedo, F; Soberón, J; Snow, A A

    2005-08-30

    In 2000, transgenes were detected in local maize varieties (landraces) in the mountains of Oaxaca, Mexico [Quist, D. & Chapela, I. H. (2001) Nature 414, 541-543]. This region is part of the Mesoamerican center of origin for maize (Zea mays L.), and the genetic diversity that is maintained in open-pollinated landraces is recognized as an important genetic resource of great cultural value. The presence of transgenes in landraces was significant because transgenic maize has never been approved for cultivation in Mexico. Here we provide a systematic survey of the frequency of transgenes in currently grown landraces. We sampled maize seeds from 870 plants in 125 fields and 18 localities in the state of Oaxaca during 2003 and 2004. We then screened 153,746 sampled seeds for the presence of two transgene elements from the 35S promoter of the cauliflower mosaic virus and the nopaline synthase gene (nopaline synthase terminator) from Agrobacterium tumefaciens. One or both of these transgene elements are present in all transgenic commercial varieties of maize. No transgenic sequences were detected with highly sensitive PCR-based markers, appropriate positive and negative controls, and duplicate samples for DNA extraction. We conclude that transgenic maize seeds were absent or extremely rare in the sampled fields. This study provides a much-needed preliminary baseline for understanding the biological, socioeconomic, and ethical implications of the inadvertent dispersal of transgenes from the United States and elsewhere to local landraces of maize in Mexico.

  7. Intensity and resolution enhancement of local regions for object detection and tracking in wide area surveillance

    NASA Astrophysics Data System (ADS)

    Krieger, Evan; Asari, Vijayan K.; Arigela, Saibabu; Aspiras, Theus

    2015-05-01

    Object tracking in wide area motion imagery is a complex problem that consists of object detection and target tracking over time. This challenge can be solved by human analysts who naturally have the ability to keep track of an object in a scene. A computer vision solution for object tracking has the potential to be a much faster and efficient solution. However, a computer vision solution faces certain challenges that do not affect a human analyst. To overcome these challenges, a tracking process is proposed that is inspired by the known advantages of a human analyst. First, the focus of a human analyst is emulated by doing processing only the local object search area. Second, it is proposed that an intensity enhancement process should be done on the local area to allow features to be detected in poor lighting conditions. This simulates the ability of the human eye to discern objects in complex lighting conditions. Third, it is proposed that the spatial resolution of the local search area is increased to extract better features and provide more accurate feature matching. A quantitative evaluation is performed to show tracking improvement using the proposed method. The three databases, each grayscale sequences that were obtained from aircrafts, used for these evaluations include the Columbus Large Image Format database, the Large Area Image Recorder database, and the Sussex database.

  8. Absence of detectable transgenes in local landraces of maize in Oaxaca, Mexico (2003–2004)

    PubMed Central

    Ortiz-García, S.; Ezcurra, E.; Schoel, B.; Acevedo, F.; Soberón, J.; Snow, A. A.

    2005-01-01

    In 2000, transgenes were detected in local maize varieties (landraces) in the mountains of Oaxaca, Mexico [Quist, D. & Chapela, I. H. (2001) Nature 414, 541–543]. This region is part of the Mesoamerican center of origin for maize (Zea mays L.), and the genetic diversity that is maintained in open-pollinated landraces is recognized as an important genetic resource of great cultural value. The presence of transgenes in landraces was significant because transgenic maize has never been approved for cultivation in Mexico. Here we provide a systematic survey of the frequency of transgenes in currently grown landraces. We sampled maize seeds from 870 plants in 125 fields and 18 localities in the state of Oaxaca during 2003 and 2004. We then screened 153,746 sampled seeds for the presence of two transgene elements from the 35S promoter of the cauliflower mosaic virus and the nopaline synthase gene (nopaline synthase terminator) from Agrobacterium tumefaciens. One or both of these transgene elements are present in all transgenic commercial varieties of maize. No transgenic sequences were detected with highly sensitive PCR-based markers, appropriate positive and negative controls, and duplicate samples for DNA extraction. We conclude that transgenic maize seeds were absent or extremely rare in the sampled fields. This study provides a much-needed preliminary baseline for understanding the biological, socioeconomic, and ethical implications of the inadvertent dispersal of transgenes from the United States and elsewhere to local landraces of maize in Mexico. PMID:16093316

  9. Impact of climate change on global malaria distribution.

    PubMed

    Caminade, Cyril; Kovats, Sari; Rocklov, Joacim; Tompkins, Adrian M; Morse, Andrew P; Colón-González, Felipe J; Stenlund, Hans; Martens, Pim; Lloyd, Simon J

    2014-03-04

    Malaria is an important disease that has a global distribution and significant health burden. The spatial limits of its distribution and seasonal activity are sensitive to climate factors, as well as the local capacity to control the disease. Malaria is also one of the few health outcomes that has been modeled by more than one research group and can therefore facilitate the first model intercomparison for health impacts under a future with climate change. We used bias-corrected temperature and rainfall simulations from the Coupled Model Intercomparison Project Phase 5 climate models to compare the metrics of five statistical and dynamical malaria impact models for three future time periods (2030s, 2050s, and 2080s). We evaluated three malaria outcome metrics at global and regional levels: climate suitability, additional population at risk and additional person-months at risk across the model outputs. The malaria projections were based on five different global climate models, each run under four emission scenarios (Representative Concentration Pathways, RCPs) and a single population projection. We also investigated the modeling uncertainty associated with future projections of populations at risk for malaria owing to climate change. Our findings show an overall global net increase in climate suitability and a net increase in the population at risk, but with large uncertainties. The model outputs indicate a net increase in the annual person-months at risk when comparing from RCP2.6 to RCP8.5 from the 2050s to the 2080s. The malaria outcome metrics were highly sensitive to the choice of malaria impact model, especially over the epidemic fringes of the malaria distribution.

  10. Impact of climate change on global malaria distribution

    PubMed Central

    Caminade, Cyril; Kovats, Sari; Rocklov, Joacim; Tompkins, Adrian M.; Morse, Andrew P.; Colón-González, Felipe J.; Stenlund, Hans; Martens, Pim; Lloyd, Simon J.

    2014-01-01

    Malaria is an important disease that has a global distribution and significant health burden. The spatial limits of its distribution and seasonal activity are sensitive to climate factors, as well as the local capacity to control the disease. Malaria is also one of the few health outcomes that has been modeled by more than one research group and can therefore facilitate the first model intercomparison for health impacts under a future with climate change. We used bias-corrected temperature and rainfall simulations from the Coupled Model Intercomparison Project Phase 5 climate models to compare the metrics of five statistical and dynamical malaria impact models for three future time periods (2030s, 2050s, and 2080s). We evaluated three malaria outcome metrics at global and regional levels: climate suitability, additional population at risk and additional person-months at risk across the model outputs. The malaria projections were based on five different global climate models, each run under four emission scenarios (Representative Concentration Pathways, RCPs) and a single population projection. We also investigated the modeling uncertainty associated with future projections of populations at risk for malaria owing to climate change. Our findings show an overall global net increase in climate suitability and a net increase in the population at risk, but with large uncertainties. The model outputs indicate a net increase in the annual person-months at risk when comparing from RCP2.6 to RCP8.5 from the 2050s to the 2080s. The malaria outcome metrics were highly sensitive to the choice of malaria impact model, especially over the epidemic fringes of the malaria distribution. PMID:24596427

  11. Identifying Malaria Transmission Foci for Elimination Using Human Mobility Data.

    PubMed

    Ruktanonchai, Nick W; DeLeenheer, Patrick; Tatem, Andrew J; Alegana, Victor A; Caughlin, T Trevor; Zu Erbach-Schoenberg, Elisabeth; Lourenço, Christopher; Ruktanonchai, Corrine W; Smith, David L

    2016-04-01

    Humans move frequently and tend to carry parasites among areas with endemic malaria and into areas where local transmission is unsustainable. Human-mediated parasite mobility can thus sustain parasite populations in areas where they would otherwise be absent. Data describing human mobility and malaria epidemiology can help classify landscapes into parasite demographic sources and sinks, ecological concepts that have parallels in malaria control discussions of transmission foci. By linking transmission to parasite flow, it is possible to stratify landscapes for malaria control and elimination, as sources are disproportionately important to the regional persistence of malaria parasites. Here, we identify putative malaria sources and sinks for pre-elimination Namibia using malaria parasite rate (PR) maps and call data records from mobile phones, using a steady-state analysis of a malaria transmission model to infer where infections most likely occurred. We also examined how the landscape of transmission and burden changed from the pre-elimination setting by comparing the location and extent of predicted pre-elimination transmission foci with modeled incidence for 2009. This comparison suggests that while transmission was spatially focal pre-elimination, the spatial distribution of cases changed as burden declined. The changing spatial distribution of burden could be due to importation, with cases focused around importation hotspots, or due to heterogeneous application of elimination effort. While this framework is an important step towards understanding progressive changes in malaria distribution and the role of subnational transmission dynamics in a policy-relevant way, future work should account for international parasite movement, utilize real time surveillance data, and relax the steady state assumption required by the presented model.

  12. Identifying Malaria Transmission Foci for Elimination Using Human Mobility Data

    PubMed Central

    Ruktanonchai, Nick W.; DeLeenheer, Patrick; Tatem, Andrew J.; Alegana, Victor A.; Caughlin, T. Trevor; zu Erbach-Schoenberg, Elisabeth; Lourenço, Christopher; Ruktanonchai, Corrine W.; Smith, David L.

    2016-01-01

    Humans move frequently and tend to carry parasites among areas with endemic malaria and into areas where local transmission is unsustainable. Human-mediated parasite mobility can thus sustain parasite populations in areas where they would otherwise be absent. Data describing human mobility and malaria epidemiology can help classify landscapes into parasite demographic sources and sinks, ecological concepts that have parallels in malaria control discussions of transmission foci. By linking transmission to parasite flow, it is possible to stratify landscapes for malaria control and elimination, as sources are disproportionately important to the regional persistence of malaria parasites. Here, we identify putative malaria sources and sinks for pre-elimination Namibia using malaria parasite rate (PR) maps and call data records from mobile phones, using a steady-state analysis of a malaria transmission model to infer where infections most likely occurred. We also examined how the landscape of transmission and burden changed from the pre-elimination setting by comparing the location and extent of predicted pre-elimination transmission foci with modeled incidence for 2009. This comparison suggests that while transmission was spatially focal pre-elimination, the spatial distribution of cases changed as burden declined. The changing spatial distribution of burden could be due to importation, with cases focused around importation hotspots, or due to heterogeneous application of elimination effort. While this framework is an important step towards understanding progressive changes in malaria distribution and the role of subnational transmission dynamics in a policy-relevant way, future work should account for international parasite movement, utilize real time surveillance data, and relax the steady state assumption required by the presented model. PMID:27043913

  13. Single photon detection and localization accuracy with an ebCMOS camera

    NASA Astrophysics Data System (ADS)

    Cajgfinger, T.; Dominjon, A.; Barbier, R.

    2015-07-01

    The CMOS sensor technologies evolve very fast and offer today very promising solutions to existing issues facing by imaging camera systems. CMOS sensors are very attractive for fast and sensitive imaging thanks to their low pixel noise (1e-) and their possibility of backside illumination. The ebCMOS group of IPNL has produced a camera system dedicated to Low Light Level detection and based on a 640 kPixels ebCMOS with its acquisition system. After reminding the principle of detection of an ebCMOS and the characteristics of our prototype, we confront our camera to other imaging systems. We compare the identification efficiency and the localization accuracy of a point source by four different photo-detection devices: the scientific CMOS (sCMOS), the Charge Coupled Device (CDD), the Electron Multiplying CCD (emCCD) and the Electron Bombarded CMOS (ebCMOS). Our ebCMOS camera is able to identify a single photon source in less than 10 ms with a localization accuracy better than 1 μm. We report as well efficiency measurement and the false positive identification of the ebCMOS camera by identifying more than hundreds of single photon sources in parallel. About 700 spots are identified with a detection efficiency higher than 90% and a false positive percentage lower than 5. With these measurements, we show that our target tracking algorithm can be implemented in real time at 500 frames per second under a photon flux of the order of 8000 photons per frame. These results demonstrate that the ebCMOS camera concept with its single photon detection and target tracking algorithm is one of the best devices for low light and fast applications such as bioluminescence imaging, quantum dots tracking or adaptive optics.

  14. Locally centred Mahalanobis distance: a new distance measure with salient features towards outlier detection.

    PubMed

    Todeschini, Roberto; Ballabio, Davide; Consonni, Viviana; Sahigara, Faizan; Filzmoser, Peter

    2013-07-17

    Outlier detection is a prerequisite to identify the presence of aberrant samples in a given set of data. The identification of such diverse data samples is significant particularly for multivariate data analysis where increasing data dimensionality can easily hinder the data exploration and such outliers often go undetected. This paper is aimed to introduce a novel Mahalanobis distance measure (namely, a pseudo-distance) termed as locally centred Mahalanobis distance, derived by centering the covariance matrix at each data sample rather than at the data centroid as in the classical covariance matrix. Two parameters, called as Remoteness and Isolation degree, were derived from the resulting pairwise distance matrix and their salient features facilitated a better identification of atypical samples isolated from the rest of the data, thus reflecting their potential application towards outlier detection. The Isolation degree demonstrated to be able to detect a new kind of outliers, that is, isolated samples within the data domain, thus resulting in a useful diagnostic tool to evaluate the reliability of predictions obtained by local models (e.g. k-NN models). To better understand the role of Remoteness and Isolation degree in identification of such aberrant data samples, some simulated and published data sets from literature were considered as case studies and the results were compared with those obtained by using Euclidean distance and classical Mahalanobis distance.

  15. Robust Statistical Approaches for RSS-Based Floor Detection in Indoor Localization

    PubMed Central

    Razavi, Alireza; Valkama, Mikko; Lohan, Elena Simona

    2016-01-01

    Floor detection for indoor 3D localization of mobile devices is currently an important challenge in the wireless world. Many approaches currently exist, but usually the robustness of such approaches is not addressed or investigated. The goal of this paper is to show how to robustify the floor estimation when probabilistic approaches with a low number of parameters are employed. Indeed, such an approach would allow a building-independent estimation and a lower computing power at the mobile side. Four robustified algorithms are to be presented: a robust weighted centroid localization method, a robust linear trilateration method, a robust nonlinear trilateration method, and a robust deconvolution method. The proposed approaches use the received signal strengths (RSS) measured by the Mobile Station (MS) from various heard WiFi access points (APs) and provide an estimate of the vertical position of the MS, which can be used for floor detection. We will show that robustification can indeed increase the performance of the RSS-based floor detection algorithms. PMID:27258279

  16. Detection and localization of continuous gravitational waves with pulsar timing arrays: the role of pulsar terms

    NASA Astrophysics Data System (ADS)

    Zhu, X.-J.; Wen, L.; Xiong, J.; Xu, Y.; Wang, Y.; Mohanty, S. D.; Hobbs, G.; Manchester, R. N.

    2016-09-01

    A pulsar timing array is a Galactic-scale detector of nanohertz gravitational waves (GWs). Its target signals contain two components: the `Earth term' and the `pulsar term' corresponding to GWs incident on the Earth and pulsar, respectively. In this work we present a Frequentist method for the detection and localization of continuous waves that takes into account the pulsar term and is significantly faster than existing methods. We investigate the role of pulsar terms by comparing a full-signal search with an Earth-term-only search for non-evolving black hole binaries. By applying the method to synthetic data sets, we find that (i) a full-signal search can slightly improve the detection probability (by about five per cent); (ii) sky localization is biased if only Earth terms are searched for and the inclusion of pulsar terms is critical to remove such a bias; (iii) in the case of strong detections (with signal-to-noise ratio ≳30), it may be possible to improve pulsar distance estimation through GW measurements.

  17. Robust Statistical Approaches for RSS-Based Floor Detection in Indoor Localization.

    PubMed

    Razavi, Alireza; Valkama, Mikko; Lohan, Elena Simona

    2016-05-31

    Floor detection for indoor 3D localization of mobile devices is currently an important challenge in the wireless world. Many approaches currently exist, but usually the robustness of such approaches is not addressed or investigated. The goal of this paper is to show how to robustify the floor estimation when probabilistic approaches with a low number of parameters are employed. Indeed, such an approach would allow a building-independent estimation and a lower computing power at the mobile side. Four robustified algorithms are to be presented: a robust weighted centroid localization method, a robust linear trilateration method, a robust nonlinear trilateration method, and a robust deconvolution method. The proposed approaches use the received signal strengths (RSS) measured by the Mobile Station (MS) from various heard WiFi access points (APs) and provide an estimate of the vertical position of the MS, which can be used for floor detection. We will show that robustification can indeed increase the performance of the RSS-based floor detection algorithms.

  18. Hook Wire Localization Procedure and Early Detection of Breast Cancer - Our Experience

    PubMed Central

    Dimitrovska, Maja Jakimovska; Mitreska, Nadica; Lazareska, Menka; Jovanovska, Elizabeta Stojovska; Dodevski, Ace; Stojkoski, Aleksandar

    2015-01-01

    AIM: The purpose of this study is to describe our experience with needle localization technique in diagnosing small breast cancers. MATERIAL AND METHODS: This retrospective study included a hundred and twenty patients’ with impalpable breast lesions and they underwent wire localization. All patients had mammography, ultrasound exam and pathohystological results. We use Mammomat Inspiration Siemens digital unit for diagnosing mammography, machine - Lorad Affinity with fenestrated compressive pad for wire localization and ultrasound machine Acuson X300 with linear array probe 10 MhZ. We use two types of wire: Bard hook wire and Kopans breast lesion localization needle, Cook. Comparative radiologic and pathologic data were collected and analyzed. RESULTS: In 120 asymptomatic women, 68 malignancies and 52 benign findings were detected with mammography and ultrasound. The mean age for patients with malignancy was 58.6 years. According BI-RADS classification for mammography the distribution is our group was: BI-RADS 3 was presented in 6 (8.82%) patients, BI-RADS 4 was presented in 56 (82.35%) patients and BI-RADS 5 was present in 6 (8.82%) of the patients. Most wire localizations were performed under mammographic guidance in 58 from 68 patients with malignant lesions (85.29%) and with ultrasound in 10 (14.7%). According the mammographic findings patients with mass on mammograms were 29 (42.65%), mass with calcifications 9 (13.23%), calcifications 20 (29.41%) and architectural distortions or asymmetry 10 (14.71%). CONCLUSION: Wire localization is a well established technique for the management of impalpable breast lesions. PMID:27275234

  19. Malaria: Biology and Disease.

    PubMed

    Cowman, Alan F; Healer, Julie; Marapana, Danushka; Marsh, Kevin

    2016-10-20

    Malaria has been a major global health problem of humans through history and is a leading cause of death and disease across many tropical and subtropical countries. Over the last fifteen years renewed efforts at control have reduced the prevalence of malaria by over half, raising the prospect that elimination and perhaps eradication may be a long-term possibility. Achievement of this goal requires the development of new tools including novel antimalarial drugs and more efficacious vaccines as well as an increased understanding of the disease and biology of the parasite. This has catalyzed a major effort resulting in development and regulatory approval of the first vaccine against malaria (RTS,S/AS01) as well as identification of novel drug targets and antimalarial compounds, some of which are in human clinical trials.

  20. Improving the Detectability of the Catalan Seismic Network for Local Seismic Activity Monitoring

    NASA Astrophysics Data System (ADS)

    Jara, Jose Antonio; Frontera, Tànit; Batlló, Josep; Goula, Xavier

    2016-04-01

    The seismic survey of the territory of Catalonia is mainly performed by the regional seismic network operated by the Cartographic and Geologic Institute of Catalonia (ICGC). After successive deployments and upgrades, the current network consists of 16 permanent stations equipped with 3 component broadband seismometers (STS2, STS2.5, CMG3ESP and CMG3T), 24 bits digitizers (Nanometrics Trident) and VSAT telemetry. Data are continuously sent in real-time via Hispasat 1D satellite to the ICGC datacenter in Barcelona. Additionally, data from other 10 stations of neighboring areas (Spain, France and Andorra) are continuously received since 2011 via Internet or VSAT, contributing both to detect and to locate events affecting the region. More than 300 local events with Ml ≥ 0.7 have been yearly detected and located in the region. Nevertheless, small magnitude earthquakes, especially those located in the south and south-west of Catalonia may still go undetected by the automatic detection system (DAS), based on Earthworm (USGS). Thus, in order to improve the detection and characterization of these missed events, one or two new stations should be installed. Before making the decision about where to install these new stations, the performance of each existing station is evaluated taking into account the fraction of detected events using the station records, compared to the total number of events in the catalogue, occurred during the station operation time from January 1, 2011 to December 31, 2014. These evaluations allow us to build an Event Detection Probability Map (EDPM), a required tool to simulate EDPMs resulting from different network topology scenarios depending on where these new stations are sited, and becoming essential for the decision-making process to increase and optimize the event detection probability of the seismic network.

  1. Imported malaria in Kuwait.

    PubMed

    Hira, P R; Behbehani, K; Al-Kandari, S

    1985-01-01

    The number of imported malaria cases in Kuwait rose from 87 in 1980 to 504 in 1983, an increase of 579%. The continued resurgence of malaria in endemic zones, improved diagnostic techniques and a heightened awareness of imported malaria have contributed to the increase in the number of microscopically proved cases. Thick blood films fixed in acetone and stained in Giemsa proved a rapid method of diagnosis; species identification on the basis of a thin film on the same slide was performed with ease. Malaria was acquired in 38 countries. Most patients were young male adults. Most of the cases were due to Plasmodium vivax originating from India, although an increasing number of P. falciparum cases are also now being diagnosed from there. P. falciparum infections were evenly distributed throughout the year and most cases presented within 14 days of their arrival in the country. The highest number of P. vivax cases were diagnosed between May and October, when heat stress might have been a factor in precipitating a clinical attack of an infection previously acquired in the endemic zone. Attention is drawn to the importance of delayed attacks of P. vivax and, in semi-immunes, of P. falciparum. The time interval involved in establishing a history of "recent" travel in clinically suspected cases of malaria needs to be more clearly defined in each geographical area. Cases of induced malaria due to transfusion, accidental and congenital infections were identified. The fatality rate due to P. falciparum infections was low. In terms of the risk of renewed transmission, Kuwait may be considered a vulnerable area.

  2. Protective role of brain water channel AQP4 in murine cerebral malaria

    PubMed Central

    Promeneur, Dominique; Lunde, Lisa Kristina; Amiry-Moghaddam, Mahmood; Agre, Peter

    2013-01-01

    Tragically common among children in sub-Saharan Africa, cerebral malaria is characterized by rapid progression to coma and death. In this study, we used a model of cerebral malaria appearing in C57BL/6 WT mice after infection with the rodent malaria parasite Plasmodium berghei ANKA. Expression and cellular localization of the brain water channel aquaporin-4 (AQP4) was investigated during the neurological syndrome. Semiquantitative real-time PCR comparing uninfected and infected mice showed a reduction of brain AQP4 transcript in cerebral malaria, and immunoblots revealed reduction of brain AQP4 protein. Reduction of brain AQP4 protein was confirmed in cerebral malaria by quantitative immunogold EM; however, polarized distribution of AQP4 at the perivascular and subpial astrocyte membranes was not altered. To further examine the role of AQP4 in cerebral malaria, WT mice and littermates genetically deficient in AQP4 were infected with P. berghei. Upon development of cerebral malaria, WT and AQP4-null mice exhibited similar increases in width of perivascular astroglial end-feet in brain. Nevertheless, the AQP4-null mice exhibited more severe signs of cerebral malaria with greater brain edema, although disruption of the blood–brain barrier was similar in both groups. In longitudinal studies, cerebral malaria appeared nearly 1 d earlier in the AQP4-null mice, and reduced survival was noted when chloroquine rescue was attempted. We conclude that the water channel AQP4 confers partial protection against cerebral malaria. PMID:23277579

  3. Protective role of brain water channel AQP4 in murine cerebral malaria.

    PubMed

    Promeneur, Dominique; Lunde, Lisa Kristina; Amiry-Moghaddam, Mahmood; Agre, Peter

    2013-01-15

    Tragically common among children in sub-Saharan Africa, cerebral malaria is characterized by rapid progression to coma and death. In this study, we used a model of cerebral malaria appearing in C57BL/6 WT mice after infection with the rodent malaria parasite Plasmodium berghei ANKA. Expression and cellular localization of the brain water channel aquaporin-4 (AQP4) was investigated during the neurological syndrome. Semiquantitative real-time PCR comparing uninfected and infected mice showed a reduction of brain AQP4 transcript in cerebral malaria, and immunoblots revealed reduction of brain AQP4 protein. Reduction of brain AQP4 protein was confirmed in cerebral malaria by quantitative immunogold EM; however, polarized distribution of AQP4 at the perivascular and subpial astrocyte membranes was not altered. To further examine the role of AQP4 in cerebral malaria, WT mice and littermates genetically deficient in AQP4 were infected with P. berghei. Upon development of cerebral malaria, WT and AQP4-null mice exhibited similar increases in width of perivascular astroglial end-feet in brain. Nevertheless, the AQP4-null mice exhibited more severe signs of cerebral malaria with greater brain edema, although disruption of the blood-brain barrier was similar in both groups. In longitudinal studies, cerebral malaria appeared nearly 1 d earlier in the AQP4-null mice, and reduced survival was noted when chloroquine rescue was attempted. We conclude that the water channel AQP4 confers partial protection against cerebral malaria.

  4. Event detection and localization for small mobile robots using reservoir computing.

    PubMed

    Antonelo, E A; Schrauwen, B; Stroobandt, D

    2008-08-01

    Reservoir Computing (RC) techniques use a fixed (usually randomly created) recurrent neural network, or more generally any dynamic system, which operates at the edge of stability, where only a linear static readout output layer is trained by standard linear regression methods. In this work, RC is used for detecting complex events in autonomous robot navigation. This can be extended to robot localization tasks which are solely based on a few low-range, high-noise sensory data. The robot thus builds an implicit map of the environment (after learning) that is used for efficient localization by simply processing the input stream of distance sensors. These techniques are demonstrated in both a simple simulation environment and in the physically realistic Webots simulation of the commercially available e-puck robot, using several complex and even dynamic environments.

  5. Locality Preserving Projection Based on Endmember Extraction for Hyperspectral Image Dimensionality Reduction and Target Detection.

    PubMed

    Wang, Yiting; Huang, Shiqi; Liu, Zhigang; Wang, Hongxia; Liu, Daizhi

    2016-09-01

    In order to reduce the effect of spectral variability on calculation precision for the weighted matrix in the locality preserving projection (LPP) algorithm, an improved dimensionality reduction method named endmember extraction-based locality preserving projection (EE-LPP) is proposed in this paper. The method primarily uses the vertex component analysis (VCA) method to extract endmember spectra from hyperspectral imagery. It then calculates the similarity between pixel spectra and the endmember spectra by using the spectral angle distance, and uses it as the basis for selecting neighboring pixels in the image and constructs a weighted matrix between pixels. Finally, based on the weighted matrix, the idea of the LPP algorithm is applied to reduce the dimensions of hyperspectral image data. Experimental results of real hyperspectral data demonstrate that the low-dimensional features acquired by the proposed methods can fully reflect the characteristics of the original image and further improve target detection accuracy.

  6. Detection and localization of GLUTs 1, 2, 3 and 5 in donkey spermatozoa.

    PubMed

    Bucci, D; Spinaci, M; Vallorani, C; Contri, A; Carluccio, A; Isani, G; Tamanini, C; Galeati, G

    2010-10-01

    GLUTs are a family of proteins that facilitate the transport of glucose and other hexoses through the plasma membrane of the cells. GLUTs are present in mammalian spermatozoon's membrane in different isoforms and they supply metabolic substrates for all the cell's activities such as motility, homoeostasis and fertilization. As studies about donkey spermatozoa and their metabolism are lacking, this study was aimed at detecting GLUTs 1, 2, 3 and 5 presence by western blotting technique and at determining their localization on the plasma membrane by indirect immunofluorescence. Each protein showed a typical localization on the sperm cells' plasma membrane, differencing the one to the other on the basis of the hexose they transport. We also highlighted some differences between GLUTs distribution and molecular weight in donkey spermatozoa and its nearest relative, the horse.

  7. RadTrac : A system for detecting, localizing, and tracking radioactive sources in real time.

    SciTech Connect

    Vilim, R.; Klann, R.; Nuclear Engineering Division

    2009-10-01

    Within the homeland security and emergency response communities, there is a need for a low-profile system to detect and locate radioactive sources. RadTrac has been developed at Argonne National Laboratory as an integrated system for the detection, localization, identification, and tracking of radioactive sources in real time. The system is based on a network of radiation detectors and advanced signal-processing algorithms. Features include video surveillance, automated tracking, easy setup, and logging of all data and images. This paper describes the advanced algorithms that were developed and implemented for source detection, localization, and tracking in real time. In the physio-spatial integration approach to source localization, counts from multiple detectors are processed according to the underlying physics linking these counts to obtain the probability that a source is present at any point in space. This information is depicted in a probability density function map. This type of depiction allows the results to be presented in a simple, easy-to-understand manner. It also allows for many different complicated factors to be accounted for in a single image as each factor is computed as a probability density in space. These factors include spatial limitations, variable shielding, directional detectors, moving detectors, and different detector sizes and orientations. The utility and versatility of this approach is described in further detail. Advanced signal-processing algorithms have also been incorporated to improve real-time tracking and to increase signal-to-noise ratios including temporal linking and energy binning. Measurements aimed at demonstrating the sensitivity improvements through the use of advanced signal-processing techniques were performed and are presented. Results of tracking weak sources (<100 {micro}Ci {sup 137}Cs) using four fixed-position detectors are presented.

  8. Machine-learning model observer for detection and localization tasks in clinical SPECT-MPI

    NASA Astrophysics Data System (ADS)

    Parages, Felipe M.; O'Connor, J. Michael; Pretorius, P. Hendrik; Brankov, Jovan G.

    2016-03-01

    In this work we propose a machine-learning MO based on Naive-Bayes classification (NB-MO) for the diagnostic tasks of detection, localization and assessment of perfusion defects in clinical SPECT Myocardial Perfusion Imaging (MPI), with the goal of evaluating several image reconstruction methods used in clinical practice. NB-MO uses image features extracted from polar-maps in order to predict lesion detection, localization and severity scores given by human readers in a series of 3D SPECT-MPI. The population used to tune (i.e. train) the NB-MO consisted of simulated SPECT-MPI cases - divided into normals or with lesions in variable sizes and locations - reconstructed using filtered backprojection (FBP) method. An ensemble of five human specialists (physicians) read a subset of simulated reconstructed images, and assigned a perfusion score for each region of the left-ventricle (LV). Polar-maps generated from the simulated volumes along with their corresponding human scores were used to train five NB-MOs (one per human reader), which are subsequently applied (i.e. tested) on three sets of clinical SPECT-MPI polar maps, in order to predict human detection and localization scores. The clinical "testing" population comprises healthy individuals and patients suffering from coronary artery disease (CAD) in three possible regions, namely: LAD, LcX and RCA. Each clinical case was reconstructed using three reconstruction strategies, namely: FBP with no SC (i.e. scatter compensation), OSEM with Triple Energy Window (TEW) SC method, and OSEM with Effective Source Scatter Estimation (ESSE) SC. Alternative Free-Response (AFROC) analysis of perfusion scores shows that NB-MO predicts a higher human performance for scatter-compensated reconstructions, in agreement with what has been reported in published literature. These results suggest that NB-MO has good potential to generalize well to reconstruction methods not used during training, even for reasonably dissimilar datasets (i

  9. Multiscale Transient Signal Detection: Localizing Transients in Geodetic Data Through Wavelet Transforms and Sparse Estimation Techniques

    NASA Astrophysics Data System (ADS)

    Riel, B.; Simons, M.; Agram, P.

    2012-12-01

    Transients are a class of deformation signals on the Earth's surface that can be described as non-periodic accumulation of strain in the crust. Over seismically and volcanically active regions, these signals are often challenging to detect due to noise and other modes of deformation. Geodetic datasets that provide precise measurements of surface displacement over wide areas are ideal for exploiting both the spatial and temporal coherence of transient signals. We present an extension to the Multiscale InSAR Time Series (MInTS) approach for analyzing geodetic data by combining the localization benefits of wavelet transforms (localizing signals in space) with sparse optimization techniques (localizing signals in time). Our time parameterization approach allows us to reduce geodetic time series to sparse, compressible signals with very few non-zero coefficients corresponding to transient events. We first demonstrate the temporal transient detection by analyzing GPS data over the Long Valley caldera in California and along the San Andreas fault near Parkfield, CA. For Long Valley, we are able to resolve the documented 2002-2003 uplift event with greater temporal precision. Similarly for Parkfield, we model the postseismic deformation by specific integrated basis splines characterized by timescales that are largely consistent with postseismic relaxation times. We then apply our method to ERS and Envisat InSAR datasets consisting of over 200 interferograms for Long Valley and over 100 interferograms for Parkfield. The wavelet transforms reduce the impact of spatially correlated atmospheric noise common in InSAR data since the wavelet coefficients themselves are essentially uncorrelated. The spatial density and extended temporal coverage of the InSAR data allows us to effectively localize ground deformation events in both space and time with greater precision than has been previously accomplished.

  10. Metabolomics and malaria biology

    PubMed Central

    Lakshmanan, Viswanathan; Rhee, Kyu Y.; Daily, Johanna P.

    2010-01-01

    Metabolomics has ushered in a novel and multi-disciplinary realm in biological research. It has provided researchers with a platform to combine powerful biochemical, statistical, computational, and bioinformatics techniques to delve into the mysteries of biology and disease. The application of metabolomics to study malaria parasites represents a major advance in our approach towards gaining a more comprehensive perspective on parasite biology and disease etiology. This review attempts to highlight some of the important aspects of the field of metabolomics, and its ongoing and potential future applications to malaria research. PMID:20970461

  11. Research toward Malaria Vaccines

    NASA Astrophysics Data System (ADS)

    Miller, Louis H.; Howard, Russell J.; Carter, Richard; Good, Michael F.; Nussenzweig, Victor; Nussenzweig, Ruth S.

    1986-12-01

    Malaria exacts a toll of disease to people in the Tropics that seems incomprehensible to those only familiar with medicine and human health in the developed world. The methods of molecular biology, immunology, and cell biology are now being used to develop an antimalarial vaccine. The Plasmodium parasites that cause malaria have many stages in their life cycle. Each stage is antigenically distinct and potentially could be interrupted by different vaccines. However, achieving complete protection by vaccination may require a better understanding of the complexities of B- and T-cell priming in natural infections and the development of an appropriate adjuvant for use in humans.

  12. Malaria vector species in Colombia - A review

    PubMed Central

    Montoya-Lerma, James; Solarte, Yezid A; Giraldo-Calderón, Gloria Isabel; Quiñones, Martha L; Ruiz-López, Freddy; Wilkerson, Richard C; González, Ranulfo

    2016-01-01

    Here we present a comprehensive review of the literature on the vectorial importance of the major Anopheles malaria vectors in Colombia. We provide basic information on the geographical distribution, altitudinal range, immature habitats, adult behaviour, feeding preferences and anthropophily, endophily and infectivity rates. We additionally review information on the life cycle, longevity and population fluctuation of Colombian Anopheles species. Emphasis was placed on the primary vectors that have been epidemiologically incriminated in malaria transmission: Anopheles darlingi, Anopheles albimanus and Anopheles nuneztovari. The role of a selection of local, regional or secondary vectors (e.g., Anopheles pseudopunctipennis and Anopheles neivai) is also discussed. We highlight the importance of combining biological, morphological and molecular data for the correct taxonomical determination of a given species, particularly for members of the species complexes. We likewise emphasise the importance of studying the bionomics of primary and secondary vectors along with an examination of the local conditions affecting the transmission of malaria. The presence and spread of the major vectors and the emergence of secondary species capable of transmitting human Plasmodia are of great interest. When selecting control measures, the anopheline diversity in the region must be considered. Variation in macroclimate conditions over a species’ geographical range must be well understood and targeted to plan effective control measures based on the population dynamics of the local Anopheles species. PMID:21881778

  13. Isotropic proton-detected local-field nuclear magnetic resonancein solids

    SciTech Connect

    Havlin, Robert H.; Walls, Jamie D.; Pines, Alexander

    2004-08-04

    A new nuclear magnetic resonance (NMR) method is presented which produces linear, isotropic proton-detected local-field spectra for InS spin systems in powdered samples. The method, HETeronuclear Isotropic Evolution (HETIE), refocuses the anisotropic portion of the heteronuclear dipolar coupling frequencies by evolving the system under a series of specially designed Hamiltonians and evolution pathways. The theory behind HETIE is represented along with experimental studies conducted on a powdered sample of ferrocene, demonstrating the methodology outlined in this paper. Applications of HETIE for structural determination in solid-state NMR are discussed.

  14. Eliminating Malaria in the American South: An Analysis of the Decline of Malaria in 1930s Alabama

    PubMed Central

    Mohler, George

    2013-01-01

    Until the 1930s, malaria was endemic throughout large swaths of the American South. We used a Poisson mixture model to analyze the decline of malaria at the county level in Alabama (an archetypical Deep South cotton state) during the 1930s. Employing a novel data set, we argue that, contrary to a leading theory, the decline of malaria in the American South was not caused by population movement away from malarial areas or the decline of Southern tenant farming. We elaborate and provide evidence for an alternate explanation that emphasizes the role of targeted New Deal–era public health interventions and the development of local-level public health infrastructure. We show that, rather than disappearing as a consequence of social change or economic improvements, malaria was eliminated in the Southern United States in the face of economic dislocation and widespread and deep-seated poverty. PMID:23763415

  15. Eliminating malaria in the American South: an analysis of the decline of malaria in 1930s Alabama.

    PubMed

    Sledge, Daniel; Mohler, George

    2013-08-01

    Until the 1930s, malaria was endemic throughout large swaths of the American South. We used a Poisson mixture model to analyze the decline of malaria at the county level in Alabama (an archetypical Deep South cotton state) during the 1930s. Employing a novel data set, we argue that, contrary to a leading theory, the decline of malaria in the American South was not caused by population movement away from malarial areas or the decline of Southern tenant farming. We elaborate and provide evidence for an alternate explanation that emphasizes the role of targeted New Deal-era public health interventions and the development of local-level public health infrastructure. We show that, rather than disappearing as a consequence of social change or economic improvements, malaria was eliminated in the Southern United States in the face of economic dislocation and widespread and deep-seated poverty.

  16. A cross-sectional analysis of traditional medicine use for malaria alongside free antimalarial drugs treatment amongst adults in high-risk malaria endemic provinces of Indonesia

    PubMed Central

    Suswardany, Dwi Linna; Sibbritt, David W.; Supardi, Sudibyo; Pardosi, Jerico F.; Chang, Sungwon; Adams, Jon

    2017-01-01

    Background The level of traditional medicine use, particularly Jamu use, in Indonesia is substantial. Indonesians do not always seek timely treatment for malaria and may seek self-medication via traditional medicine. This paper reports findings from the first focused analyses of traditional medicine use for malaria in Indonesia and the first such analyses worldwide to draw upon a large sample of respondents across high-risk malaria endemic areas. Methods A sub-study of the Indonesia Basic Health Research/Riskesdas Study 2010 focused on 12,226 adults aged 15 years and above residing in high-risk malaria-endemic provinces. Logistic regression was undertaken to determine the significant associations for traditional medicine use for malaria symptoms. Findings Approximately one in five respondents use traditional medicine for malaria symptoms and the vast majority experiencing multiple episodes of malaria use traditional medicine alongside free antimalarial drug treatments. Respondents consuming traditional medicine for general health/common illness purposes every day (odds ratio: 3.75, 95% Confidence Interval: 2.93 4.79), those without a hospital in local vicinity (odds ratio: 1.31, 95% Confidence Interval: 1.10 1.57), and those living in poorer quality housing, were more likely to use traditional medicine for malaria symptoms. Conclusion A substantial percentage of those with malaria symptoms utilize traditional medicine for treating their malaria symptoms. In order to promote safe and effective malaria treatment, all providing malaria care in Indonesia need to enquire with their patients about possible traditional medicine use. PMID:28329019

  17. Predictors of malaria-association with rubber plantations in Thailand

    PubMed Central

    2012-01-01

    Background The national Global Fund-supported malaria (GFM) program in Thailand, which focuses on the household-level implementation of vector control via insecticide-treated nets (ITNs)/long-lasting insecticidal nets (LLINs) combined with indoor residual spraying (IRS), has been combating malaria risk situations in different provinces with complex epidemiological settings. By using the perception of malaria villagers (MVs), defined as villagers who recognized malaria burden and had local understanding of mosquitoes, malaria, and ITNs/LLINs and practiced preventive measures, this study investigated the predictors for malaria that are associated with rubber plantations in an area of high household-level implementation coverage of IRS (2007–2010) and ITNs/LLINs (2008–2010) in Prachuap Khiri Khan Province. Methods A structured questionnaire addressing socio-demographics, household characteristics and health behavioral factors (knowledge, perceptions and practices) regarding the performed interventions was administered to the 313 households (70 malaria-affected and 243 malaria-unaffected) that had respondents aged ≥18 years of both genders. In the univariate and multivariate analyses, only 246 (78.6%) MV respondents (62 malaria-affected and 184 malaria-unaffected) were analyzed to determine the predictors for risk (morbidity). Results The majority (70%) of households were covered by IRS. For a combination of ITNs/LLINs, there were 74% of malaria-affected households covered and 46% of malaria-unaffected households. In a logistic regression analysis using odds ratios (aORs) adjusted on the variables and a 95% confidence interval (CI), malaria affecting MVs was associated with daily worker (i.e., earning daily income by normally practicing laborious activities mostly in agriculture such as rubber tapping and rubber sheet processing at the smallholdings of rubber plantations) (aOR = 2.9, 95% CI: 1.1-7.4), low-moderate level of malaria knowledge (aOR = 2.4, 95% CI: 1

  18. Malaria control in Nicaragua: social and political influences on disease transmission and control activities.

    PubMed

    Garfield, R

    1999-07-31

    Throughout Central America, a traditional malaria control strategy (depending on heavy use of organic pesticides) became less effective during the 1970s. In Nicaragua, an alternative strategy, based on frequent local epidemiological assessments and community participation, was developed in the 1980s. Despite war-related social instability, and continuing vector resistance, this approach was highly successful. By the end of the contra war, there finally existed organisational and ecological conditions that favoured improved malaria control. Yet the expected improvements did not occur. In the 1990s, Nicaragua experienced its worst recorded malaria epidemics. This situation was partly caused by the country's macroeconomic structural adjustment programme. Volunteers now take fewer slides and provide less treatment, malaria control workers are less motivated by the spirit of public service, and some malaria control stations charge for diagnosis or treatment. To "roll back malaria", in Nicaragua at least, will require the roll-back of some erroneous aspects of structural adjustment.

  19. Severe Malaria Complicated by G6PD Deficiency in a Pediatric Tanzanian Immigrant

    PubMed Central

    Damhoff, Heather N.; Stadler, Laura P.

    2014-01-01

    Approximately 1,500 cases of malaria are diagnosed in the United States each year. Most cases are travelers and immigrants returning from parts of the world where malaria transmission occurs. Malaria is the most frequent cause of systemic febrile illness without localizing symptoms in travelers returning from the developing world, so vigilance by providers is needed when evaluating patients returning from areas in which malaria is endemic. Despite the availability of effective treatment, malaria still accounts for more than 1 million deaths per year worldwide, with rates being disproportionately high in young children under the age of 5. We present the case of a 4-year-old refugee who emigrated from Tanzania with severe malaria due to dual infections of Plasmodium falciparum and P. ovale, whose treatment course was complicated by quinidine gluconate cardiotoxicity and glucose-6-phosphate dehydrogenase deficiency. PMID:25762879

  20. Detection and localization using an acoustic array on a small robotic platform

    NASA Astrophysics Data System (ADS)

    Young, Stuart H.; Scanlon, Michael V.

    2003-09-01

    The future battlefield will require an unprecedented level of automation in which soldier-operated autonomous and semi-autonomous ground, air and sea platforms along with mounted and dismounted soldiers will function as a tightly coupled team. Sophisticated robotic platforms with diverse sensor suites will be an integral part of the Objective Force, and must be able to collaborate not only amongst themselves but also with their manned partners. The Army Research Laboratory has developed a robot-based acoustic detection system that will detect and localize on an impulsive noise event, such as a sniper's weapon firing. Additionally, acoustic sensor arrays worn on a soldier's helmet or equipment can enhance his situational awareness and RSTA capabilities. The Land Warrior or Objective Force Warrior body-worn computer can detect tactically significant impulsive signatures from bullets, mortars, artillery, and missiles or spectral signatures from tanks, helicopters, UAVs, and mobile robots. Time-difference-of-arrival techniques can determine a sound's direction of arrival, while head attitude sensors can instantly determine the helmet orientation at time of capture. With precision GPS location of the soldier, along with the locations of other soldiers, robots, or unattended ground sensors that heard the same event, triangulation techniques can produce an accurate location of the target. Data from C-4 explosions and 0.50-Caliber shots shows that both helmet and robot systems can localize on the same event. This provides an awesome capability - mobile robots and soldiers working together on an ever-changing battlespace to detect the enemy and improve the survivability, mobility, and lethality of our future warriors.

  1. Transmission Risk from Imported Plasmodium vivax Malaria in the China-Myanmar Border Region.

    PubMed

    Wang, Duoquan; Li, Shengguo; Cheng, Zhibin; Xiao, Ning; Cotter, Chris; Hwang, Jimee; Li, Xishang; Yin, Shouqin; Wang, Jiazhi; Bai, Liang; Zheng, Zhi; Wang, Sibao

    2015-10-01

    Malaria importation and local vector susceptibility to imported Plasmodium vivax infection are a continuing risk along the China-Myanmar border. Malaria transmission has been prevented in 3 border villages in Tengchong County, Yunnan Province, China, by use of active fever surveillance, integrated vector control measures, and intensified surveillance and response.

  2. Twin signal signature sensing: Application to shorted winding monitoring, detection and localization

    SciTech Connect

    Streifel, R.J.; Marks, R.J.; El-Sharkawi, A.E.; Kerszenbaum, I.

    1995-12-31

    Using twin signal sensing we propose a method to monitor, detect and localize shorts in power system devices with windings: including rotors, transformers and motors. There has, to date, been no effective way to do so. The most obvious approach, time domain reflectometry, fails due to the reactive coupling of the windings. Twin signal signature sensing of shorts results from identical signals being simultaneously injected in both sides of the windings. The reflected signals are measured and the difference amplified to produce the signature signal. The signature signal characterizes the current state of the windings. When winding shorts are present, the electrical characteristics of the device will be different and thus the signature signal will also change. The changes in the signature signal can be monitored to detect shorted windings. While a device is in operation, the signature signals can be monitored and the development of winding shorts can be diagnosed through the process of novelty detection. After a device is cleaned or otherwise known to be functioning correctly (no winding shorts), signature signals can be collected which represent the healthy device. If a sufficient number of signals can be collected, the signal space representing healthy windings can be characterized. A detection surface can be placed around the healthy signature signals to provide a partition of the signal space into two regions: healthy and faulty. Any signature signal which is not within the healthy signature partition will indicate a faulted device.

  3. Dynamic N-occupancy models: estimating demographic rates and local abundance from detection-nondetection data.

    PubMed

    Rossman, Sam; Yackulic, Charles B; Saunders, Sarah P; Reid, Janice; Davis, Ray; Zipkin, Elise F

    2016-12-01

    Occupancy modeling is a widely used analytical technique for assessing species distributions and range dynamics. However, occupancy analyses frequently ignore variation in abundance of occupied sites, even though site abundances affect many of the parameters being estimated (e.g., extinction, colonization, detection probability). We introduce a new model ("dynamic N-occupancy") capable of providing accurate estimates of local abundance, population gains (reproduction/immigration), and apparent survival probabilities while accounting for imperfect detection using only detection/nondetection data. Our model utilizes heterogeneity in detection based on variations in site abundances to estimate latent demographic rates via a dynamic N-mixture modeling framework. We validate our model using simulations across a wide range of values and examine the data requirements, including the number of years and survey sites needed, for unbiased and precise estimation of parameters. We apply our model to estimate spatiotemporal heterogeneity in abundances of barred owls (Strix varia) within a recently invaded region in Oregon (USA). Estimates of apparent survival and population gains are consistent with those from a nearby radio-tracking study and elucidate how barred owl abundances have increased dramatically over time. The dynamic N-occupancy model greatly improves inferences on individual-level population processes from occupancy data by explicitly modeling the latent population structure.

  4. A simple frequency-based delamination detection and localization method without baseline model

    NASA Astrophysics Data System (ADS)

    Guechaichia, A.; Trendafilova, I.

    2012-08-01

    This study suggests a novel non-model-based method for structural vibration-based health monitoring for composite laminated beams which utilises only the first natural frequency of the beam in order to detect and localise delamination. The method is based on the application of a static force in different positions along the beam. It is shown that the application of a static force on a damaged beam induces forces that push the delaminated layers together resulting in an increase of stiffness to a maximum when the static force is applied on the top and the middle of the delamination area. This stiffness increase in turn causes changes in the structural natural frequencies. The method does not require the frequency of the beam in its baseline condition. A very simple procedure for damage detection is suggested which uses a static force applied at only three points along the beam to detect and localise delamination. The method is numerically validated for a simply supported beam, using a finite element model of the beam. Our results show that the frequency variation with the change of the force application point can be used to detect, localize and in the same time quantify very precisely single delamination.

  5. Measuring Socioeconomic Inequalities in Relation to Malaria Risk: A Comparison of Metrics in Rural Uganda

    PubMed Central

    Tusting, Lucy S.; Rek, John C.; Arinaitwe, Emmanuel; Staedke, Sarah G.; Kamya, Moses R.; Bottomley, Christian; Johnston, Deborah; Lines, Jo; Dorsey, Grant; Lindsay, Steve W.

    2016-01-01

    Socioeconomic position (SEP) is an important risk factor for malaria, but there is no consensus on how to measure SEP in malaria studies. We evaluated the relative strength of four indicators of SEP in predicting malaria risk in Nagongera, Uganda. A total of 318 children resident in 100 households were followed for 36 months to measure parasite prevalence routinely every 3 months and malaria incidence by passive case detection. Household SEP was determined using: 1) two wealth indices, 2) income, 3) occupation, and 4) education. Wealth Index I (reference) included only asset ownership variables. Wealth Index II additionally included food security and house construction variables, which may directly affect malaria. In multivariate analysis, only Wealth Index II and income were associated with the human biting rate, only Wealth Indices I and II were associated with parasite prevalence, and only caregiver's education was associated with malaria incidence. This is the first evaluation of metrics beyond wealth and consumption indices for measuring the association between SEP and malaria. The wealth index still predicted malaria risk after excluding variables directly associated with malaria, but the strength of association was lower. In this setting, wealth indices, income, and education were stronger predictors of socioeconomic differences in malaria risk than occupation. PMID:26811432

  6. Mosquito Vectors and the Globalization of Plasmodium falciparum Malaria.

    PubMed

    Molina-Cruz, Alvaro; Zilversmit, Martine M; Neafsey, Daniel E; Hartl, Daniel L; Barillas-Mury, Carolina

    2016-11-23

    Plasmodium falciparum malaria remains a devastating public health problem. Recent discoveries have shed light on the origin and evolution of Plasmodium parasites and their interactions with their vertebrate and mosquito hosts. P. falciparum malaria originated in Africa from a single horizontal transfer between an infected gorilla and a human, and became global as the result of human migration. Today, P. falciparum malaria is transmitted worldwide by more than 70 different anopheline mosquito species. Recent studies indicate that the mosquito immune system can be a barrier to malaria transmission and that the P. falciparum Pfs47 gene allows the parasite to evade mosquito immune detection. Here, we review the origin and globalization of P. falciparum and integrate this history with analysis of the biology, evolution, and dispersal of the main mosquito vectors. This new perspective broadens our understanding of P. falciparum population structure and the dispersal of important parasite genetic traits.

  7. Modelling climate change and malaria transmission.

    PubMed

    Parham, Paul E; Michael, Edwin

    2010-01-01

    The impact of climate change on human health has received increasing attention in recent years, with potential impacts due to vector-borne diseases only now beginning to be understood. As the most severe vector-borne disease, with one million deaths globally in 2006, malaria is thought most likely to be affected by changes in climate variables due to the sensitivity of its transmission dynamics to environmental conditions. While considerable research has been carried out using statistical models to better assess the relationship between changes in environmental variables and malaria incidence, less progress has been made on developing process-based climate-driven mathematical models with greater explanatory power. Here, we develop a simple model of malaria transmission linked to climate which permits useful insights into the sensitivity of disease transmission to changes in rainfall and temperature variables. Both the impact of changes in the mean values of these key external variables and importantly temporal variation in these values are explored. We show that the development and analysis of such dynamic climate-driven transmission models will be crucial to understanding the rate at which P. falciparum and P. vivax may either infect, expand into or go extinct in populations as local environmental conditions change. Malaria becomes endemic in a population when the basic reproduction number R0 is greater than unity and we identify an optimum climate-driven transmission window for the disease, thus providing a useful indicator for determing how transmission risk may change as climate changes. Overall, our results indicate that considerable work is required to better understand ways in which global malaria incidence and distribution may alter with climate change. In particular, we show that the roles of seasonality, stochasticity and variability in environmental variables, as well as ultimately anthropogenic effects, require further study. The work presented here

  8. A randomized longitudinal factorial design to assess malaria vector control and disease management interventions in rural Tanzania.

    PubMed

    Kramer, Randall A; Mboera, Leonard E G; Senkoro, Kesheni; Lesser, Adriane; Shayo, Elizabeth H; Paul, Christopher J; Miranda, Marie Lynn

    2014-05-16

    The optimization of malaria control strategies is complicated by constraints posed by local health systems, infrastructure, limited resources, and the complex interactions between infection, disease, and treatment. The purpose of this paper is to describe the protocol of a randomized factorial study designed to address this research gap. This project will evaluate two malaria control interventions in Mvomero District, Tanzania: (1) a disease management strategy involving early detection and treatment by community health workers using rapid diagnostic technology; and (2) vector control through community-supported larviciding. Six study villages were assigned to each of four groups (control, early detection and treatment, larviciding, and early detection and treatment plus larviciding). The primary endpoint of interest was change in malaria infection prevalence across the intervention groups measured during annual longitudinal cross-sectional surveys. Recurring entomological surveying, household surveying, and focus group discussions will provide additional valuable insights. At baseline, 962 households across all 24 villages participated in a household survey; 2,884 members from 720 of these households participated in subsequent malariometric surveying. The study design will allow us to estimate the effect sizes of different intervention mixtures. Careful documentation of our study protocol may also serve other researchers designing field-based intervention trials.

  9. Changes in malaria morbidity and mortality in Mpumalanga Province, South Africa (2001- 2009): a retrospective study

    PubMed Central

    2012-01-01

    results highlight the need to continue with IRS together with other control strategies until interruption in local malaria transmission is completely achieved. However, the goal to eliminate malaria as a public health problem requires efforts to be directed towards the control of imported malaria cases; development of strategies to interrupt local transmission; and maintaining high quality surveillance and reporting system. PMID:22239855

  10. Computer-aided diagnosis: detection and localization of prostate cancer within the peripheral zone.

    PubMed

    Rampun, Andrik; Chen, Zhili; Malcolm, Paul; Tiddeman, Bernie; Zwiggelaar, Reyer

    2016-05-01

    We propose a methodology for prostate cancer detection and localization within the peripheral zone based on combining multiple segmentation techniques. We extract four image features using Gaussian and median filters. Subsequently, we use each image feature separately to generate binary segmentations. Finally, we take the intersection of all four binary segmentations, incorporating a model of the peripheral zone, and perform erosion to remove small false-positive regions. The initial evaluation of this method is based on 275 MRI images from 37 patients, and 86% of the slices were classified correctly with 87% and 86% sensitivity and specificity achieved, respectively. This paper makes two contributions: firstly, a novel computer-aided diagnosis approach, which is based on combining multiple segmentation techniques using only a small number of simple image features, and secondly, the development of the proposed method and its application in prostate cancer detection and localization using a single MRI modality with the results comparable with the state-of-the-art multimodality and advanced computer vision methods in the literature. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Fast approach to evaluate map reconstruction for lesion detection and localization

    SciTech Connect

    Qi, Jinyi; Huesman, Ronald H.

    2004-02-01

    Lesion detection is an important task in emission tomography. Localization ROC (LROC) studies are often used to analyze the lesion detection and localization performance. Most researchers rely on Monte Carlo reconstruction samples to obtain LROC curves, which can be very time-consuming for iterative algorithms. In this paper we develop a fast approach to obtain LROC curves that does not require Monte Carlo reconstructions. We use a channelized Hotelling observer model to search for lesions, and the results can be easily extended to other numerical observers. We theoretically analyzed the mean and covariance of the observer output. Assuming the observer outputs are multivariate Gaussian random variables, an LROC curve can be directly generated by integrating the conditional probability density functions. The high-dimensional integrals are calculated using a Monte Carlo method. The proposed approach is very fast because no iterative reconstruction is involved. Computer simulations show that the results of the proposed method match well with those obtained using the tradition LROC analysis.

  12. Local isotropic phase symmetry measure for detection of beta cells and lymphocytes

    PubMed Central

    Kuse, Manohar; Wang, Yi-Fang; Kalasannavar, Vinay; Khan, Michael; Rajpoot, Nasir

    2011-01-01

    Diabetes can be associated with a reduction in functional β cell mass, which must be restored if the disease is to be cured or progress is to be arrested. To study the cell count, it is also necessary to determine the number of nuclei within the insulin stained area. It can take a single experimentalist several months to complete a single study of this kind, results of which may still be quite subjective. In this paper, we propose a framework based on a novel measure of local symmetry for detection of cells. The local isotropic phase symmetry measure (LIPSyM) is designed to give high values at or near the cell centers. We demonstrate the effectiveness of our algorithm for detection of two types of specific cells in histology images, cells in mouse pancreatic sections and lymphocytes in human breast tissue. Experimental results for these two problems show that our algorithm performs better than human experts for the former problem, and outperforms the best reported results for the latter. PMID:22811958

  13. Electromagnetic and acoustic bimodality for the detection and localization of electrical arc faults

    NASA Astrophysics Data System (ADS)

    Vasile, C.; Ioana, C.; Digulescu, A.; Candel, I.

    2016-12-01

    Electrical arc faults pose an important problem to electrical installations worldwide, be it production facilities or distribution systems. In this context, it is easy to assess the economic repercussions of such a fault, when power supply is cut off downstream of its location, while also realizing that an early detection of the on-site smaller scale faults would be of great benefit. This articles serves as a review of the current state-of-the-art work that has been carried out on the subject of detection and localization of electrical arc faults, by exploiting the bimodality of this phenomenon, which generates simultaneously electromagnetic and acoustic waves, propagating in a free space path. En experimental setup has been defined, to demonstrate principles stated in previous works by the authors, and signal processing methods have been used in order to determine the DTOA (difference-of-time-of-arrival) of the acoustic signals, which allows localization of the transient fault. In the end there is a discussion regarding the results and further works, which aims to validate this approach in more real-life applications.

  14. Detection of localized inclusions of gold nanoparticles in Intralipid-1% by point-radiance spectroscopy.

    PubMed

    Grabtchak, Serge; Palmer, Tyler J; Whelan, William M

    2011-07-01

    Interstitial fiber-optic-based approaches used in both diagnostic and therapeutic applications rely on localized light-tissue interactions. We present an optical technique to identify spectrally and spatially specific exogenous chromophores in highly scattering turbid media. Point radiance spectroscopy is based on directional light collection at a single point with a side-firing fiber that can be rotated up to 360 deg. A side firing fiber accepts light within a well-defined, solid angle, thus potentially providing an improved spatial resolution. Measurements were performed using an 800-μm diameter isotropic spherical diffuser coupled to a halogen light source and a 600 μm, ∼43 deg cleaved fiber (i.e., radiance detector). The background liquid-based scattering phantom was fabricated using 1% Intralipid. Light was collected with 1 deg increments through 360 deg-segment. Gold nanoparticles , placed into a 3.5-mm diameter capillary tube were used as localized scatterers and absorbers introduced into the liquid phantom both on- and off-axis between source and detector. The localized optical inhomogeneity was detectable as an angular-resolved variation in the radiance polar plots. This technique is being investigated as a potential noninvasive optical modality for prostate cancer monitoring.

  15. Ligand Binding Site Detection by Local Structure Alignment and Its Performance Complementarity

    PubMed Central

    Lee, Hui Sun; Im, Wonpil

    2013-01-01

    Accurate determination of potential ligand binding sites (BS) is a key step for protein function characterization and structure-based drug design. Despite promising results of template-based BS prediction methods using global structure alignment (GSA), there is a room to improve the performance by properly incorporating local structure alignment (LSA) because BS are local structures and often similar for proteins with dissimilar global folds. We present a template-based ligand BS prediction method using G-LoSA, our LSA tool. A large benchmark set validation shows that G-LoSA predicts drug-like ligands’ positions in single-chain protein targets more precisely than TM-align, a GSA-based method, while the overall success rate of TM-align is better. G-LoSA is particularly efficient for accurate detection of local structures conserved across proteins with diverse global topologies. Recognizing the performance complementarity of G-LoSA to TM-align and a non-template geometry-based method, fpocket, a robust consensus scoring method, CMCS-BSP (Complementary Methods and Consensus Scoring for ligand Binding Site Prediction), is developed and shows improvement on prediction accuracy. The G-LoSA source code is freely available at http://im.bioinformatics.ku.edu/GLoSA. PMID:23957286

  16. Sentinel node detection and radioguided occult lesion localization in breast cancer.

    PubMed

    Trifirò, Guiseppe; Lavinia Travaini, Laura; De Cicco, Concetta; Paganelli, Giovanni

    2006-01-01

    Sentinel lymph node biopsy might replace complete axillary dissection for staging of the axilla in clinically N0 breast cancer patients and represent a significant advantage as a minimally invasive procedure, considering that about 70% of patients are found to be free from metastatic disease, yet axillary node dissection can lead to significant morbidity. In our Institute, Radioguided Occult Lesion Localization is the standard method to locate non-palpable breast lesions and the gamma probes is very effective in assisting intra-operative localization and removal, as in sentinel node biopsy. The rapid spread of sentinel lymph node biopsy has led to its use in clinical settings previously considered contraindications to sentinel lymph node biopsy. In this contest, we evaluated in a large group of patients possible factors affecting sentinel node detection and the reliability of sentinel lymph node biopsy carried out after large excisional breast biopsy. Our data confirm that a previous breast surgery does not prohibit efficient sentinel lymph node localization and sentinel lymph node biopsy can correctly stage the axialla in these patients.

  17. Turbulent bubbly flow: A new method for robust local phase detection

    NASA Astrophysics Data System (ADS)

    Luther, Stefan

    2002-11-01

    Hot--film anemometry is one of the standard techniques for measurements in turbulent two phase flows. The time series contains valuable information about the local properties of the fluid as well as the gaseous phase. However, the disentanglement of the fluid and gaseous part of the signal is intricate due to its multiscale nature. Hitherto methods require an a priori knowledge of probability distribution of the signal or its derivatives. At low Reynolds number this distribution is assumed to be bi--modal and therefore an optimal (Bayesian) classifier can be derived. At high Reynolds number turbulent flow, this assumption is in general not valid. This leads to faulty classification due to intermittency or strong velocity fluctuations. We propose a novel algorithm which reformulates the problem of local phase detection as an general pattern recognition task. The algorithm consists of an optimal signal decomposition using wavelet packet dictionaries and local basis discrimination. The classification is done by learning vector quantization. The performance of the algorithm is validated for turbulent bubbly flows at various Reynolds numbers and void fractions. In particular, we discuss the feasibility of the algorithm for the evaluation of structure functions and velocity spectra, focusing on the scaling properties.

  18. Detection and localization of particle-emitting sources with compound-eye inspired detector arrays

    NASA Astrophysics Data System (ADS)

    Liu, Zhi

    2007-08-01

    We develop methods to detect and localize particle-emitting sources using detector arrays that are inspired by biological compound eyes. The sources of interest may be optical, nuclear, or cosmic; they emit particles such as visible photons, neutrons, protons, or charged particles. Our results may have wide applications to artificial vision, which can be important in robotics (robot vision) or medicine (e.g., artificial e