bluuebunny/crossref_metadata_2025 huggingface dataset:
ANTIGENICITY, IMMUNOGENICITY, AND PROTECTIVE EFFICACY OF PLASMODIUM VIVAX MSP1 PV200L: A POTENTIAL MALARIA VACCINE SUBUNIT
Authors: VALDERRAMA-AGUIRRE AUGUSTO , QUINTERO GUSTAVO , GÓMEZ ANDRÉS , CASTELLANOS ALEJANDRO , PÉREZ YOBANA , MÉNDEZ FABIÁN , ARÉVALO-HERRERA MYRIAM , HERRERA SÓCRATES
Published: May 2017

The merozoite surface protein 1 (MSP-1) is expressed in all Plasmodium species and is considered a major malaria vaccine candidate. We found that MSP-1 from Plasmodium vivax (PvMSP-1) contains a region of significant sequence homology with the 190L subunit vaccine derived from the P. falciparum MSP-1. The fragment, termed Pv200L, was expressed as a recombinant protein in Escherichia coli (rPv200L) and used to asses its immunologic relevance as a vaccine target. A cross-sectional, seroepidemiologic study conducted in Buenaventura, Colombia showed that 52.2% (95% confidence interval [CI] = 39.8–64.3) of individuals previously exposed to P. vivax and 72.8% (95% CI = 61.8–82.1) of P. vivax–infected patients had IgG antibodies to rPv200L. Immunization of BALB/c mice and Aotus monkeys induced IgG antibodies (titer > 106) that cross-reacted with P. vivax parasites. Immunized monkeys displayed partial protection against a challenge with P. vivax blood stages. Our results suggest that Pv200L is a new malaria vaccine subunit and deserves further testing.
SAFETY AND ELICITATION OF HUMORAL AND CELLULAR RESPONSES IN COLOMBIAN MALARIA-NAIVE VOLUNTEERS BY A PLASMODIUM VIVAX CIRCUMSPOROZOITE PROTEIN–DERIVED SYNTHETIC VACCINE
Authors: HERRERA SÓCRATES , BONELO ANILZA , PERLAZA BLANCA LILIANA , FERNÁNDEZ OLGA LUCÍA , VICTORIA LEONARDO , LENIS ANA MILENA , SOTO LILIANA , HURTADO HUGO , ACUÑA LINA MARÍA , VÉLEZ JUAN DIEGO , PALACIOS RICARDO , CHEN-MOK MARIO , CORRADIN GIAMPIETRO , ARÉVALO-HERRERA MYRIAM
Published: May 2017

Substantial experimental evidence indicates that the Plasmodium circumsporozoite (CS) protein has great potential as a vaccine candidate. We tested the safety and immunogenicity of vaccines composed of P. vivax CS-derived synthetic peptides. Sixty-nine healthy, malaria-naive volunteers were randomized to receive three injections of placebo or synthetic proteins N, R, or C (10, 30, or 100 μg/dose) in a double-blinded fashion. Vaccines were well tolerated and no serious adverse events were observed. Peptides N and R elicited humoral responses at all doses; peptide C elicicted these responses only at doses of 30 and 100 μg. The N peptide at a dose of 100 μg elicited the greatest antibody response. Antibodies to the three peptides recognized P. vivax sporozoites in an immunofluorescent antibody test. Peripheral blood mononuclear cells from most immunized volunteers also produced interferon-γ upon peptide in vitro stimulation. These vaccines appear safe, well tolerated, and immunogenic in malaria-naive volunteers. Further optimization and development of this vaccine is being attempted to conduct phase II clinical trials.
INDUCTION OF TRANSMISSION-BLOCKING IMMUNITY IN AOTUS MONKEYS BY VACCINATION WITH A PLASMODIUM VIVAX CLINICAL GRADE PVS25 RECOMBINANT PROTEIN
Authors: ARÉVALO-HERRERA MYRIAM , SOLARTE YEZID , YASNOT MARÍA FERNANDA , CASTELLANOS ANGÉLICA , RINCÓN ADRIANA , SAUL ALLAN , MU JIANBING , LONG CAROLE , MILLER LOUIS , HERRERA SÓCRATES
Published: May 2017

Aotus monkeys were used to determine the immunogenicity of Pvs25 protein expressed in the zygote/ookinete surface. Animals were immunized in three times with 100 μg of Pvs25 formulated in Montanide ISA-720. Antibodies to Pvs25 detected by an enzyme-linked immunosorbent assay appeared by day 30 after the first immunization, with a peak of antibodies levels on day 150. These antibodies were still detectable on day 300. Plasma samples on day 150 from experimental group were able to completely block the development of the parasite in Anopheles albimanus mosquitoes artificially fed with human isolates of Plasmodium vivax. Immunized Aotus monkeys were infected with blood forms of the P. vivax Salvador I strain and no boosting effect of blood infection on titers of antibodies to Pvs25 was observed despite the presence of infective gametocytes. In conclusion, Pvs25 protein formulated in Montanide ISA-720 induces efficient and long-lasting transmission-blocking antibodies that cannot be boosted by parasite infection.
ANTIBODY RESPONSE TO PLASMODIUM VIVAX ANTIGENS IN FY-NEGATIVE INDIVIDUALS FROM THE COLOMBIAN PACIFIC COAST
Authors: HERRERA SÓCRATES , GÓMEZ ANDRÉS , VERA OMAIRA , VERGARA JUANA , VALDERRAMA-AGUIRRE AUGUSTO , MAESTRE AMANDA , MÉNDEZ FABIÁN , WANG RUOBING , CHITNIS CHETAN E. , YAZDANI SYED S. , ARÉVALO-HERRERA MYRIAM
Published: May 2017

The Duffy antigen (Fy) is necessary for Plasmodium vivax invasion of human erythrocytes. Some populations have a highly prevalent Fy-negative phenotype; such persons are naturally protected from P. vivax blood infection but are expected to completely support the P. vivax pre-erythrocytic cycle, representing a valuable model for studying the immune response during these parasitic stages. We typed 214 individuals, mostly Afro-Colombians, from a P. vivax-endemic area for Fy expression and determined the antibody response to P. vivax pre-erythrocytic (sporozoites and CS) and blood-stage antigens (blood forms, P. vivax merozoite surface protein 1, and P. vivax Duffy binding protein [PvDBP]). Antibody titers to P. vivax circumsporozoite protein, P11, and N-terminal peptides and the number of responders were similar in Fy-negative and Fy-positive individuals. The number of responders to sporozoites, blood forms, and PvDBP were different between these groups. Thus, Fy-negative individuals from malaria-endemic areas can be used to study the immune response to the P. vivax liver phase without interference of the erythrocytic cycle.
MODELING A FIELD TRIAL OF THE RTS,S/AS02A MALARIA VACCINE
Authors: MAIRE NICOLAS , APONTE JOHN J. , ROSS AMANDA , THOMPSON RICARDO , ALONSO PEDRO , UTZINGER JÜRG , TANNER MARCEL , SMITH THOMAS
Published: May 2017

A double-blind, phase IIb, randomized controlled trial of the malaria vaccine RTS,S/AS02A showed an efficacy of 45.0% in reducing the force of infection for Plasmodium falciparum and of 29.9% in reducing incidence of clinical malaria in children 1–4 years of age in Manhiça, Mozambique. We simulate this trial using a stochastic model of P. falciparum epidemiology, and the setting-specific seasonal pattern of entomologic inoculations as input. The simulated incidence curve for the control group was comparable with that observed in the trial. To reproduce the observed efficacy in extending time to first infection, the model needed to assume an efficacy of 52% in reducing the force of infection. This bias arises as a result of acquired partial immunity against blood stages, thus suggesting an explanation for the lower efficacy observed in a previous trial in semi-immune adult men in The Gambia. The shape of the incidence of infection curve for the vaccine cohort in Manhiça indicates that the vaccine provides incomplete protection to a large proportion of the vaccinees, rather than offering complete protection to some recipients and none to others. This behavior is compatible with a model of no decay in efficacy over the six-month surveillance period of the trial. The model accurately reproduced the lower efficacy against clinical disease than against infection. In the simulations this finding resulted from loss of acquired clinical immunity as a result of a reduction in the force of infection in the vaccinated cohort. The model also predicted greater efficacy against severe diseases than against clinical disease. The success of the simulation model in reproducing the results of the Manhiça trial encourages us to apply the same model to predict the potential public health and economic impact if RTS,S/AS02A were to be introduced into the existing expanded program on immunization.
PREDICTIONS OF THE EPIDEMIOLOGIC IMPACT OF INTRODUCING A PRE-ERYTHROCYTIC VACCINE INTO THE EXPANDED PROGRAM ON IMMUNIZATION IN SUB-SAHARAN AFRICA
Authors: MAIRE NICOLAS , TEDIOSI FABRIZIO , ROSS AMANDA , SMITH THOMAS
Published: May 2017

We predict the effects of introduction of a pre-erythrocytic vaccine against Plasmodium falciparum into a malaria-endemic population in Africa. We use a stochastic simulation model that includes components of transmission, parasitology, and clinical epidemiology of malaria and was validated using the results of field trials of the RTS,S/AS02A vaccine. The results suggest that vaccines with efficacy similar to that of RTS,S/AS02A have a substantial impact on malaria morbidity and mortality during the first decade after their introduction, but have negligible effects on malaria transmission at levels of endemicity typical for sub-Saharan Africa. The main benefits result from prevention of morbidity and mortality in the first years of life. Vaccines with very short half-life or low efficacy may have little overall effect on incidence of severe malaria. A similar approach can be used to make predictions for other strategies for deployment of the vaccine and to other types of malaria vaccines and interventions.
THE COSTS OF INTRODUCING A MALARIA VACCINE THROUGH THE EXPANDED PROGRAM ON IMMUNIZATION IN TANZANIA
Authors: HUTTON GUY , TEDIOSI FABRIZIO
Published: May 2017

This report presents an approach to costing the delivery of a malaria vaccine through the expanded program on immunization (EPI), and presents the predicted cost per dose delivered and cost per fully immunized child (FIC) in Tanzania, which are key inputs to the cost-effectiveness analysis. The costs included in the analysis are those related to the purchase of the vaccine taking into account the wastage rate; the costs of distributing and storing the vaccine at central, zonal, district, and facility level; those of managing the vaccination program; the costs of delivery at facility level (including personnel, syringes, safety boxes, and waste management); and those of additional training of EPI personnel and of social mobilization activities. The average cost per FIC increases almost linearly from US$4.2 per FIC at a vaccine price of US$1 per dose to US$31.2 at vaccine price of US$10 per dose. The marginal cost is approximately 5% less than the average cost. Although the vaccine price still determines most of the total delivery costs, the analysis shows that other costs are relevant and should be taken into account before marketing the vaccine and planning its inclusion into the EPI.
PREDICTING THE COST-EFFECTIVENESS OF INTRODUCING A PRE-ERYTHROCYTIC MALARIA VACCINE INTO THE EXPANDED PROGRAM ON IMMUNIZATION IN TANZANIA
Authors: TEDIOSI FABRIZIO , HUTTON GUY , MAIRE NICOLAS , SMITH THOMAS A. , ROSS AMANDA , TANNER MARCEL
Published: May 2017

We model the cost-effectiveness of the introduction of a pre-erythrocytic malaria vaccine into the Expanded Program on Immunization. We use a dynamic stochastic simulation model of the epidemiology of Plasmodium falciparum in malaria-endemic areas and of case management in Tanzania. We consider a range of vaccine characteristics and a range of transmission settings. At low vaccine prices, the cost-effectiveness of such vaccines may be similar to that of other established preventative and curative interventions against malaria. The cost-effectiveness ratio increases rapidly and approximately linearly with vaccine cost per dose. The approach can be adopted for comparative analyses of the cost effectiveness of different vaccines and other intervention strategies.
A MODEL FOR NATURAL IMMUNITY TO ASEXUAL BLOOD STAGES OF PLASMODIUM FALCIPARUM MALARIA IN ENDEMIC AREAS
Authors: MAIRE NICOLAS , SMITH THOMAS , ROSS AMANDA , OWUSU-AGYEI SETH , DIETZ KLAUS , MOLINEAUX LOUIS
Published: May 2017

Most mathematical models for acquired immunity to Plasmodium falciparum consider effects of immunity on duration of infection and infectiousness, but do not consider the most evident effect of immunity, which is to reduce parasite densities. Few attempts have been made to fit such models to field data. We propose a stochastic simulation model to predict the distributions of P. falciparum parasite densities in endemic areas, in which acquired immunity acts by reducing parasite densities. We have fitted this model to age-specific prevalence and geometric mean densities from settings in Ghana, Nigeria, and Tanzania. The model appears to reproduce reasonably well the parasitologic patterns seen in malariologic surveys in endemic areas and is appropriate for predicting the impact of interventions such as vaccination in the context of continual exposure to P. falciparum.
RELATIONSHIPS BETWEEN HOST INFECTIVITY TO MOSQUITOES AND ASEXUAL PARASITE DENSITY IN PLASMODIUM FALCIPARUM
Authors: ROSS AMANDA , KILLEEN GERRY , SMITH THOMAS
Published: May 2017

We describe a statistical model for the relationship between asexual parasite densities of Plasmodium falciparum and the infectivity of the host to mosquitoes. The model takes into account the delay between asexual parasitemia and infectivity resulting from the time course of gametocytemia. It also allows for the need for the blood meal to contain gametocytes of both sexes if infection is to take place. We show that by fitting this model to data from malariatherapy patients it can explain observed patterns of infectiousness of the human host and is consistent with distributions of gametocyte densities in malariatherapy patients. By integrating this model into an individual-based simulation of human populations exposed to endemic P. falciparum transmission, we are able to predict the contributions of different host age groups to the infectious reservoir. Comparison of model predictions with published estimates of this quantity confirms that infected adults hosts are likely to make a significant contribution to the reservoir of transmission, and points to the need for improved population-based estimates of this age-dependence in infectivity of humans in endemic areas.
MATHEMATICAL MODEL OF THE FIRST WAVE OF PLASMODIUM FALCIPARUM ASEXUAL PARASITEMIA IN NON-IMMUNE AND VACCINATED INDIVIDUALS
Authors: DIETZ KLAUS , RADDATZ GÜNTER , MOLINEAUX LOUIS
Published: May 2017

We present a dynamic model of the highly pathogenic first wave of Plasmodium falciparum asexual parasitemia in non-immune persons. The model was successfully fitted to malaria therapy data. This required four case-specific parameters: the basic two-day multiplication factor, the time of onset of adaptive immunity, and the effective dose 50 densities for the innate and adaptive immune responses, respectively. All four parameters show large case-dependent variation that is mainly attributable to host factors. According to the model, the maximum value of the first wave is controlled mainly by the innate immune response. We used the model to explore the expected effects of vaccines targeting the parasite’s asexual blood stages on the basis of what we consider to be the biologically most plausible assumptions concerning the parameter modifications induced by vaccination. According to our simulations, the benefit of antiparasitic vaccination is strongly host dependent and vaccine efficacy at low immunogenicity is much larger against severe disease than against fever. This has implications for the early testing of the protective efficacy of a vaccine in humans.
AN EPIDEMIOLOGIC MODEL OF SEVERE MORBIDITY AND MORTALITY CAUSED BY PLASMODIUM FALCIPARUM
Authors: ROSS AMANDA , MAIRE NICOLAS , MOLINEAUX LOUIS , SMITH THOMAS
Published: May 2017

The intensity of Plasmodium falciparum transmission has multifarious and sometimes counter-intuitive effects on age-specific rates of severe morbidity and mortality in endemic areas. This has led to conflicting speculations about the likely impact of malaria control interventions. We propose a quantitative framework to reconcile the various apparently contradictory observations relating morbidity and mortality rates to malaria transmission. Our model considers two sub-categories of severe malaria episodes. These comprise episodes with extremely high parasite densities in hosts with little previous exposure, and acute malaria episodes accompanied by co-morbidity or other risk factors enhancing susceptibility. In addition to direct malaria mortality from severe malaria episodes, the model also considers the enhanced risk of indirect mortality following acute episodes accompanied by co-morbidity after the parasites have been cleared. We fit this model to summaries of field data from endemic areas of Africa, and show that it can account for the observed age- and exposure-specific patterns of pediatric severe malaria and malaria-associated mortality in children. This model will allow us to make predictions of the long-term impact of potential malaria interventions. Predictions for children will be more reliable than those for older people because there is a paucity of epidemiologic studies of adults and adolescents.
MODELING THE RELATIONSHIP BETWEEN THE POPULATION PREVALENCE OF PLASMODIUM FALCIPARUM MALARIA AND ANEMIA
Authors: CARNEIRO ILONA A. , SMITH THOMAS , LUSINGU JOHN P. A. , MALIMA ROBERT , UTZINGER JÜRG , DRAKELEY CHRIS J.
Published: May 2017

More than half of all young children and pregnant women are affected by anemia. Although its etiology is multi-factorial, malaria is likely to be a major contributor to chronic anemia in endemic areas. Recent reviews have examined the effect of community-based malaria control interventions on anemia. We analyze how the prevalence of anemia depends on that of Plasmodium falciparum malaria by developing models of the excess risk of anemia caused by malaria at a population level in 24 villages in northeastern Tanzania. In that setting, we estimated that the prevalence of a hemoglobin level < 8 g/dL attributable to malaria was 4.6% in infants, 4.1% in children one year of age, 2.7% in children two years of age, and 3.3% in women of childbearing age. Successful validation of our models in other malaria-endemic settings would enable their use for predicting the impact of malaria control interventions on anemia, and for long-term monitoring and surveillance of malaria.
AN APPROACH TO MODEL THE COSTS AND EFFECTS OF CASE MANAGEMENT OF PLASMODIUM FALCIPARUM MALARIA IN SUB-SAHARAN AFRICA
Authors: TEDIOSI FABRIZIO , MAIRE NICOLAS , SMITH THOMAS , HUTTON GUY , UTZINGER JÜRG , ROSS AMANDA , TANNER MARCEL
Published: May 2017

An important shortcoming of existing methods for estimating the cost-effectiveness of malaria control interventions is that the incidence of illness and transmission dynamics are assumed to be independent of the case management system. We have developed a model for case management and integrated it into a stochastic simulation of Plasmodium falciparum malaria dynamics. This allows us to predict the incidence of clinical episodes and of mortality while incorporating effects of case management on persistence of parasites and transmission. We make predictions for a range of different transmission intensities in sub-Saharan Africa and simulate a range of case management scenarios with different coverage rates. The model predicts that high treatment rates have a proportionately greater epidemiologic impact at low transmission levels. Further development is needed for models for health-seeking behavior and referral patterns. The current model is a first step towards useful predictions of the epidemiologic and economic consequences of introducing and/or scaling-up of malaria control interventions.
Towards Usable E-Health
Authors: Sousa Vanessa , Lopez Karen Dunn
Published: May 2017

Background: The use of e-health can lead to several positive outcomes. However, the potential for e-health to improve healthcare is partially dependent on its ease of use. In order to determine the usability for any technology, rigorously developed and appropriate measures must be chosen.

Objectives: To identify psychometrically tested questionnaires that measure usability of e-health tools, and to appraise their generalizability, attributes coverage, and quality.

Methods: We conducted a systematic review of studies that measured usability of e-health tools using four databases (Scopus, PubMed, CINAHL, and HAPI). Non-primary research, studies that did not report measures, studies with children or people with cognitive limitations, and studies about assistive devices or medical equipment were systematically excluded. Two authors independently extracted information including: questionnaire name, number of questions, scoring method, item generation, and psychometrics using a data extraction tool with pre-established categories and a quality appraisal scoring table.

Results: Using a broad search strategy, 5,558 potentially relevant papers were identified. After removing duplicates and applying exclusion criteria, 35 articles remained that used 15 unique questionnaires. From the 15 questionnaires, only 5 were general enough to be used across studies. Usability attributes covered by the questionnaires were: learnability (15), efficiency (12), and satisfaction (11). Memorability (1) was the least covered attribute. Quality appraisal showed that face/content (14) and construct (7) validity were the most frequent types of validity assessed. All questionnaires reported reliability measurement. Some questionnaires scored low in the quality appraisal for the following reasons: limited validity testing (7), small sample size (3), no reporting of user centeredness (9) or feasibility estimates of time, effort, and expense (7).

Conclusions: Existing questionnaires provide a foundation for research on e-health usability. However, future research is needed to broaden the coverage of the usability attributes and psychometric properties of the available questionnaires.

Citation: Sousa VEC, Lopez KD. Towards usable e-health: A systematic review of usability questionnaires. Appl Clin Inform 2017; 8: 470–490 https://doi.org/10.4338/ACI-2016-10-R-0170
Comparison of the optical depth of total ozone and atmospheric aerosols in Poprad-Gánovce, Slovakia
Authors: Hrabčák Peter
Published: May 2017

Abstract. Atmospheric ozone along with aerosols significantly affect the amount of ultraviolet solar radiation that reaches on the Earth's surface. Presented study is focused on the comparison of the optical depth of total ozone and atmospheric aerosols in the area of Poprad-Gánovce situated at the altitude of 706 meters above sea level, close to the highest peak of the Carpathian Mountains. Measurements of direct sun ultraviolet radiation are carried out here continuously since 1994 using the Brewer Ozone Spectrophotometer type MK IV. These measurements are used to calculate the total amount of atmospheric ozone and consequently its optical depth. Measurements can also be used to determine the optical depth of atmospheric aerosols using the Langley plot method. In this study, those two factors causing a significant reduction in the direct sun ultraviolet radiation to the Earth's surface are compared to each other. The study is showing results of measurements over 23 years, since 1994 to 2016. Values of optical depth are determined for wavelengths 306.3 nm, 310.1 nm, 313.5 nm, 316.8 nm and 320.1 nm. A statistically significant decrease in the total optical depth of the atmosphere was observed for all investigated wavelengths. Its main cause is the decrease of optical depth of aerosols. The study also presents comparison of the terrestrial and satellite data of total ozone and AOD. A very good match of satellite and terrestrial direct sun measurements of total ozone was found. The use of zenith sky measurements in combination with the direct sun measurements leads to the systematically higher values of total ozone. Comparison of the satellite and terrestrial AOD measurements in the UV range of the solar spectrum is mainly limited by the very low number of days for which AOD can be determined for satellite measurements. It has been found that AOD satellite data is higher than terrestrial in the long-term average.
Modeling soil organic carbon dynamics and its driving factors in global main cereal cropping systems
Authors: Wang Guocheng , Zhang Wen , Sun Wenjuan , Li Tingting , Han Pengfei
Published: May 2017

Abstract. The net fluxes of carbon dioxide (CO2) between the atmosphere and agricultural systems are mainly characterized by the changes in soil carbon stock, which is determined by the balance between carbon input from organic materials and output through soil C decomposition. The spatiotemporal changes of cropland soil organic carbon (SOC) in response to different carbon (C) input management and environmental conditions across the global main cereal systems were studied using a modeling approach. We also identified the key variables driving SOC changes at a high spatial resolution (0.1° × 0.1°) and long time scale (54 years from 1961 to 2014). The widely used soil C turnover model (RothC) and the state-of-the-art databases of soil and climate were used in the present study. The model simulations suggested that, on a global average, the cropland SOC density increased at an annual rate of 0.22, 0.45 and 0.69 MgC ha−1 yr−1 under a crop residue retention rate of 30 %, 60 % and 90 %, respectively. Increased quantity of C input could enhance the soil C sequestration or reduce the soil C loss rate, depending largely on the local soil and climate conditions. Spatially, under a certain crop residue retention rate, a relatively higher soil C sink were generally found across the central parts of the United States, western Europe, northern regions of China, while a relatively smaller soil C sink generally occurred in regions at high latitudes of both northern and southern hemisphere, and SOC decreased across the equatorial zones of Asia, Africa and America. We found that SOC change was significantly influenced by the crop residue retention rate (linearly positive), and the edaphic variable of initial SOC content (linearly negative). Temperature had weakly negative effects, and precipitation had significantly negative impacts on SOC changes. The results can help target carbon input management for effectively mitigating climate change through cropland soil C sequestration on a global scale.
Wind turbine impact on operational weather radar I/Q data: characterisation and filtering
Authors: Norin Lars
Published: May 2017

Abstract. For the past 2 decades wind turbines have been growing in number all over the world as a response to the increasing demand for renewable energy. However, the rapid expansion of wind turbines presents a problem for many radar systems, including weather radars. Wind turbines in the line of sight of a weather radar can have a negative impact on the radar's measurements. As weather radars are important instruments for meteorological offices, finding a way for wind turbines and weather radars to co-exist would be of great societal value.Doppler weather radars base their measurements on in-phase and quadrature phase (I/Q) data. In this work a month's worth of recordings of high-resolution I/Q data from an operational Swedish C-band weather radar are presented. The impact of point targets, such as masts and wind turbines, on the I/Q data is analysed and characterised. It is shown that the impact of point targets on single radar pulses, when normalised by amplitude, is manifested as a distinct and highly repeatable signature. The shape of this signature is found to be independent of the size, shape and yaw angle of the wind turbine. It is further demonstrated how the robustness of the point target signature can be used to identify and filter out the impact of wind turbines in the radar's signal processor.
Fluorescence calibration method for single-particle aerosol fluorescence instruments
Authors: Robinson Ellis Shipley , Gao Ru-Shan , Schwarz Joshua P. , Fahey David W. , Perring Anne E.
Published: May 2017

Abstract. Real-time, single-particle fluorescence instruments used to detect atmospheric bioaerosol particles are increasingly common, yet no standard fluorescence calibration method exists for this technique. This gap limits the utility of these instruments as quantitative tools and complicates comparisons between different measurement campaigns. To address this need, we have developed a method to produce size-selected particles with a known mass of fluorophore, which we use to calibrate the fluorescence detection of a Wideband Integrated Bioaerosol Sensor (WIBS-4A). We use mixed tryptophan–ammonium sulfate particles to calibrate one detector (FL1; excitation  =  280 nm, emission  =  310–400 nm) and pure quinine particles to calibrate the other (FL2; excitation  =  280 nm, emission  =  420–650 nm). The relationship between fluorescence and mass for the mixed tryptophan–ammonium sulfate particles is linear, while that for the pure quinine particles is nonlinear, likely indicating that not all of the quinine mass contributes to the observed fluorescence. Nonetheless, both materials produce a repeatable response between observed fluorescence and particle mass. This procedure allows users to set the detector gains to achieve a known absolute response, calculate the limits of detection for a given instrument, improve the repeatability of the instrumental setup, and facilitate intercomparisons between different instruments. We recommend calibration of single-particle fluorescence instruments using these methods.
A high resolution extra-terrestrial solar spectrum determined from ground-based solar irradiance measurements
Authors: Gröbner Julian , Kröger Ingo , Egli Luca , Hülsen Gregor , Riechelmann Stefan , Sperfeld Peter
Published: May 2017

Abstract. A high resolution extraterrestrial solar spectrum has been determined from ground-based measurements of direct solar spectral irradiance over the range 300 nm to 500 nm using the Langley-plot technique. The measurements were obtained at the Iza\\`na Atmospheric Research Center from AEMET, Tenerife, Spain during the period 12 to 24 September 2016. This solar spectrum (QASUMEFTS) was combined from medium resolution (bandpass of 0.86 nm) measurements of the QASUME spectroradiometer in the range 300 nm to 500 nm and high resolution measurements (0.025 nm) from a fourier transform spectroradiometer over the range 305 nm to 380 nm. The KittPeak solar atlas was used to extend this high resolution solar spectrum to 500 nm. The expanded uncertainties of this solar spectrum are 2 % between 310 nm and 500 nm and 4 % at 300 nm. The comparison of this solar spectrum with solar spectra measured in space (top of the atmosphere) gives very good agreements in some cases, while in some other cases discrepancies of up to 5 % could be observed. The QASUMEFTS solar spectrum represents a benchmark dataset with uncertainties lower than anything previously published. The metrological traceability of the measurements to the International System of Units (SI) is assured by an unbroken chain of calibrations leading to the primary spectral irradiance standard of the Physikalisch-Technische Bundesanstalt in Germany.
Geomagnetic activity and local time dependence of the distribution of ultra low-frequency wave power in azimuthal wavenumbers, m
Authors: Sarris Theodore E. , Li Xinlin
Published: May 2017

Abstract. The azimuthal wavenumber m of ultra low-frequency (ULF) waves in the magnetosphere is a required parameter in the calculations of the diffusion rates of energetic electrons and protons in the magnetosphere, as electrons and protons of drift frequency ωd have been shown to radially diffuse due to resonant interaction with ULF waves of frequency ω = mωd. However, there are difficulties in estimating m, due to lack of multipoint measurements. In this paper we use magnetic field measurements at geosynchronous orbit to calculate the cross-spectrogram power and phase differences between time series from magnetometer pairs. Subsequently, assuming that ULF waves of a certain frequency and m would be observed with a certain phase difference between two azimuthally aligned magnetometers, the fraction of the total power in each phase difference range is calculated. As part of the analysis, both quiet-time and storm-time distributions of power per m number are calculated, and it is shown that during active times, a smaller fraction of total power is confined to lower m than during quiet times. It is also shown that in the dayside region, power is distributed mostly to the lowest azimuthal wavenumbers m = 1 and 2, whereas on the nightside it is more equally distributed to all m that can be resolved by the azimuthal separation between two spacecraft.
Biological soil crust communities 12–16 years after wildfires in Idaho,
USA
Authors: Root Heather T. , Brinda John C. , Dodson E. Kyle
Published: May 2017

Abstract. Changing fire regimes in western North America may impact biological soil crust (BSC) communities that influence many ecosystem functions, such as soil stability and C and N cycling. However, longer-term effects of wildfire on BSC abundance, species richness, functional groups, and ecosystem functions after wildfire (i.e. BSC resilience) is still poorly understood. We sampled BSC lichen and bryophyte communities at four sites in Idaho, USA, within foothill steppe communities that included wildfires from 12 to 16 years old. We established six plots outside each burn perimeter and compared them with six plots of varying severity within each fire perimeter at each site. BSC cover was most strongly negatively impacted by wildfire at sites that had well-developed BSC communities in adjacent unburned plots. BSC species richness was estimated to be 65 % greater in unburned plots compared with burned plots. In contrast, there was no evidence that vascular plant functional groups or fire severity (as measured by satellite metrics dNBR or RdNBR) significantly affected longer-term BSC responses. Three BSC functional groups (squamulose lichens, vagrant lichens, and tall turf mosses) exhibited a significant decrease in abundance in burned areas relative to adjacent unburned areas. The decreases in BSC cover and richness along with decreased abundance of several functional groups suggest that wildfire can negatively impact ecosystem function in these semi-arid ecosystems for at least one to two decades. This is a concern given that increased fire frequency is predicted for the region due to exotic grass invasion and climate change.
Ecohydrological optimality in the Northeast China Transect
Authors: Cong Zhentao , Li Qinshu , Mo Kangle , Zhang Lexin , Shen Hong
Published: May 2017

Abstract. The Northeast China Transect (NECT) is one of the International Geosphere-Biosphere Program (IGBP) terrestrial transects, where there is a significant precipitation gradient from east to west, as well as a vegetation transition of forest–grassland–desert. It is remarkable to understand vegetation distribution and dynamics under climate change in this transect. We take canopy cover (M), derived from Normalized Difference Vegetation Index (NDVI), as an index to describe the properties of vegetation distribution and dynamics in the NECT. In Eagleson's ecohydrological optimality theory, the optimal canopy cover (M*) is determined by the trade-off between water supply depending on water balance and water demand depending on canopy transpiration. We apply Eagleson's ecohydrological optimality method in the NECT based on data from 2000 to 2013 to get M*, which is compared with M from NDVI to further discuss the sensitivity of M* to vegetation properties and climate factors. The result indicates that the average M* fits the actual M well (for forest, M*  =  0.822 while M  =  0.826; for grassland, M*  =  0.353 while M  =  0.352; the correlation coefficient between M and M* is 0.81). Results of water balance also match the field-measured data in the references. The sensitivity analyses show that M* decreases with the increase of leaf area index (LAI), stem fraction and temperature, while it increases with the increase of leaf angle and precipitation amount. Eagleson's ecohydrological optimality method offers a quantitative way to understand the impacts of climate change on canopy cover and provides guidelines for ecorestoration projects.
APPROACH TO 3D ANALYSIS OF GRAVITY PTOSIS
Authors: Guryanov R. A. , Monkin S. , Monkin A. , Petrov A.
Published: May 2017

Abstract. The assessment of ptosis degree for rejuvenation procedures, the choice of following operation technique and evaluation of surgery result are based on subjective visual examination and surgeon’s experience. The photogrammetric scans of 25 female patients of age 20 to 55 in vertical and supine (horizontal) position of body with placing the regular marker points on the face were analyzed. For 5 patients, also the CT data was acquired and segmentation of soft tissue was performed. Four of these patients underwent SMAS-lifting, the photogrammetry scanning was repeat 6 months after the operation. Computer vision algorithms was used for markers detection on the 3D model texture, marker were projected from texture to triangular mesh. 3D mesh models were registered with user defined anatomy points and pair selection based on markers location was done. Pairs of points on vertical and horizontal 3D models were analyzed for surface tissue mobility examination. The migration vectors of each side of the face are uniformly directed upwards and laterally. The vectors are projected at the areas of so-called ligaments demonstrate no evidence in deviation from row sequences. The volume migration is strongly correlates with the age of examined patients, on the contrary the point migration moderately correlates with age in patients of 30 to 50 years old. The analysis of migration vectors before and after the SMAS-lifting revealed no significant changes in surface points’ migration. The described method allows to assess the mechanical conditions of individual face and evaluate efficacy of surgery. This approach can be used for the classification of face ptosis grade.
FITTING A POINT CLOUD TO A 3D POLYHEDRAL SURFACE
Authors: Popov E. V. , Rotkov S. I.
Published: May 2017

Abstract. The ability to measure parameters of large-scale objects in a contactless fashion has a tremendous potential in a number of industrial applications. However, this problem is usually associated with an ambiguous task to compare two data sets specified in two different co-ordinate systems. This paper deals with the study of fitting a set of unorganized points to a polyhedral surface. The developed approach uses Principal Component Analysis (PCA) and Stretched grid method (SGM) to substitute a non-linear problem solution with several linear steps. The squared distance (SD) is a general criterion to control the process of convergence of a set of points to a target surface. The described numerical experiment concerns the remote measurement of a large-scale aerial in the form of a frame with a parabolic shape. The experiment shows that the fitting process of a point cloud to a target surface converges in several linear steps. The method is applicable to the geometry remote measurement of large-scale objects in a contactless fashion.
SMALL NODULES LOCALIZATION ON CT IMAGES OF LUNGS
Authors: Snezhko E. V. , Kharuzhyk S. A. , Tuzikov A. V. , Kovalev V. A.
Published: May 2017

Abstract. According to the World Health Organization (WHO) lung cancer remains the leading cause of death of men among all malignant tumors [1, 2]. One of the reasons of such a statistics is the fact that the lung cancer is hardly diagnosed on the yearly stages when it is almost asymptomatic. The purpose of this paper is to present a Computer-Aided Diagnosis (CAD) software developed for assistance of early detection of nodules in CT lung images including solitary pulmonary nodules (SPN) as well as multiple nodules. The efficiency of nodule localization was intended to be as high as the level of the best practice. The software developed supports several functions including lungs segmentation, selection of nodule candidates and nodule candidates filtering.
PARAMETRIC REPRESENTATION OF THE SPEAKER’S LIPS FOR MULTIMODAL SIGN LANGUAGE AND SPEECH RECOGNITION
Authors: Ryumin D. , Karpov A. A.
Published: May 2017

Abstract. In this article, we propose a new method for parametric representation of human’s lips region. The functional diagram of the method is described and implementation details with the explanation of its key stages and features are given. The results of automatic detection of the regions of interest are illustrated. A speed of the method work using several computers with different performances is reported. This universal method allows applying parametrical representation of the speaker’s lipsfor the tasks of biometrics, computer vision, machine learning, and automatic recognition of face, elements of sign languages, and audio-visual speech, including lip-reading.
ACCURACY ESTIMATION OF THE OPTICAL FLOWMETHODS IN THE IRIS STRUCTURE MOTION ANALYSIS VIA CONTROLLED DEFORMATIONS
Authors: Chigrinskiy V. V. , Matveev I. A.
Published: May 2017

Abstract. The iris structure motion is analyzed. Extension and compression of the iris structural elements are nonlinear with respect to the pupil radius change. To reveal this nonlinearity the Lucas-Kanade, Horn-Schunck and modified Horn-Chunck optical flow methods are used. To aim is to estimate the accuracies of these methods. To solve the problem an implementation of the methods on the synthetic data is proposed. The data are obtained by applying deformations, which correspond to the certain models, to the eye images. The results of the methods implementation are compared with the used models and the accuracies are estimated on the basis of this comparison. The dataset of N eye images is used to generate the synthetic videos.
THE PARALLEL IMPLEMENTATION OF ALGORITHMS FOR FINDING THE REFLECTION SYMMETRY OF THE BINARY IMAGES
Authors: Fedotova S. , Seredin O. , Kushnir O.
Published: May 2017

Abstract. In this paper, we investigate the exact method of searching an axis of binary image symmetry, based on brute-force search among all potential symmetry axes. As a measure of symmetry, we use the set-theoretic Jaccard similarity applied to two subsets of pixels of the image which is divided by some axis. Brute-force search algorithm definitely finds the axis of approximate symmetry which could be considered as ground-truth, but it requires quite a lot of time to process each image. As a first step of our contribution we develop the parallel version of the brute-force algorithm. It allows us to process large image databases and obtain the desired axis of approximate symmetry for each shape in database. Experimental studies implemented on “Butterflies” and “Flavia” datasets have shown that the proposed algorithm takes several minutes per image to find a symmetry axis. However, in case of real-world applications we need computational efficiency which allows solving the task of symmetry axis search in real or quasi-real time. So, for the task of fast shape symmetry calculation on the common multicore PC we elaborated another parallel program, which based on the procedure suggested before in (Fedotova, 2016). That method takes as an initial axis the axis obtained by superfast comparison of two skeleton primitive sub-chains. This process takes about 0.5 sec on the common PC, it is considerably faster than any of the optimized brute-force methods including ones implemented in supercomputer. In our experiments for 70 percent of cases the found axis coincides with the ground-truth one absolutely, and for the rest of cases it is very close to the ground-truth.
APPLICATION OF PHOTOGRAMMETRY TO BRAIN ANATOMY
Authors: Nocerino E. , Menna F. , Remondino F. , Sarubbo S. , De Benedictis A. , Chioffi F. , Petralia V. , Barbareschi M. , Olivetti E. , Avesani P.
Published: May 2017

Abstract. This paper presents an on-going interdisciplinary collaboration to advance brain connectivity studies. Despite the evolution of noninvasive methods to investigate the brain connectivity structure using the diffusion magnetic resonance, in the neuroscientific community there is an open debate how to collect quantitative information of the main neuroanatomical tracts. Information on the structure and main pathways of brain’s white matter are generally derived by manual dissection of the brain ex-vivo. This paper wants to present a photogrammetric method developed to support the collection of metric information of the main pathways, or set of fibres, of the white matter of brain. For this purpose, multi-temporal photogrammetric acquisitions, with a resolution better than 100 microns, are performed at different stages of the brain’s dissection, and the derived dense point clouds are used to annotate the stem, i.e., the region where there is a greater density of fibres of a given pathway, and termination points of several neuroanatomical tracts, i.e. fibres.
BLOCKWISE BINARY PATTERN: A ROBUST AND AN EFFICIENT APPROACH FOR
OFFLINE SIGNATURE VERIFICATION
Authors: Shekar B. H. , Pilar B. , Sunil K. D. S.
Published: May 2017

Abstract. This paper presents a variant of local binary pattern called Blockwise Binary Pattern (BBP) for the offline signature verification. The proposed approach has three major phases : Preprocessing, Feature extraction and Classification. In the feature extraction phase, the signature is divided into 3 x 3 neighborhood blocks. A BBP value for central pixel of each block is computed by considering its 8 neighboring pixels and the 3 x 3 block is replaced by this central pixel. To compute BBP value for each block, a binary sequence is formed by considering 8 neighbors of the central pixel, by following the pixels in a anti-clockwise direction. Then the minimum decimal equivalent of this binary sequence is computed and this value is assigned to the central pixel. The central pixel is merged with the neighboring 8 pixels representing the 3 X 3 neighborhood block. This method is found to be invariant to rotation, scaling and shift of the signature. The features are stored in the form of normalized histogram. The SVM classifier is used for the signature verification. Experiments have been performed on standard signature datasets namely CEDAR and GPDS which are publicly available English signature datasets and on MUKOS, a regional language (Kannada) dataset and compared with the well-known approaches to exhibit the performance of the proposed approach.
FEATURE VECTOR CONSTRUCTION METHOD FOR IRIS RECOGNITION
Authors: Odinokikh G. , Fartukov A. , Korobkin M. , Yoo J.
Published: May 2017

Abstract. One of the basic stages of iris recognition pipeline is iris feature vector construction procedure. The procedure represents the extraction of iris texture information relevant to its subsequent comparison. Thorough investigation of feature vectors obtained from iris showed that not all the vector elements are equally relevant. There are two characteristics which determine the vector element utility: fragility and discriminability. Conventional iris feature extraction methods consider the concept of fragility as the feature vector instability without respect to the nature of such instability appearance. This work separates sources of the instability into natural and encodinginduced which helps deeply investigate each source of instability independently. According to the separation concept, a novel approach of iris feature vector construction is proposed. The approach consists of two steps: iris feature extraction using Gabor filtering with optimal parameters and quantization with separated preliminary optimized fragility thresholds. The proposed method has been tested on two different datasets of iris images captured under changing environmental conditions. The testing results show that the proposed method surpasses all the methods considered as a prior art by recognition accuracy on both datasets.