Cytomegalovirus seropositivity is associated with herpes zoster

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Ogunjimi, Benson; Hens, Niel; Pebody, Richard; Jansens, Hilde; Seale, Holly; Quinlivan, Mark; Theeten, Heidi; Goossens, Herman; Breuer, Judy; Beutels, Philippe

2015-01-01

Herpes zoster (HZ) is caused by VZV reactivation that is facilitated by a declined immunity against varicella-zoster virus (VZV), but also occurs in immunocompetent individuals. Cytomegalovirus (CMV) infection is associated with immunosenescence meaning that VZV-specific T-cells could be less responsive. This study aimed to determine whether CMV infection could be a risk factor for the development of HZ. CMV IgG serostatus was determined in stored serum samples from previously prospectively recruited ambulatory adult HZ patients in the UK (N = 223) in order to compare the results with those from UK population samples (N = 1545) by means of a logistic regression (controlling for age and gender). Furthermore, we compared the UK population CMV seroprevalence with those from population samples from other countries (from Belgium (N1 = 1741, N2 = 576), USA (N = 5572) and Australia (N = 2080)). Furthermore, CMV IgG titers could be compared between UK HZ patients and Belgium N2 population samples because the same experimental set-up for analysis was used. We found UK ambulatory HZ patients to have a higher CMV seroprevalence than UK population samples (OR 1.56 [1.11 2.19]). CMV IgG seropositivity was a significant risk factor for HZ in the UK (OR 3.06 [1.32 7.04]. Furthermore, high CMV IgG titers (exceeding the upper threshold) were less abundant in CMV-seropositive Belgian N2 population samples than in CMV-seropositive UK HZ patients (OR 0.51 [0.31 0.82]. We found CMV-seroprevalence to increase faster with age in the UK than in other countries (P < 0.05). We conclude that CMV IgG seropositivity is associated with HZ. This finding could add to the growing list of risk factors for HZ. PMID:25905443

Assessment of local carotid stiffness in seronegative and seropositive rheumatoid arthritis.

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Aslan, Abdullah Nabi; Şirin Özcan, Ayşe Nur; Erten, Şükran; Alsancak, Yakup; Durmaz, Tahir

2017-10-01

Rheumatoid arthritis (RA) is a chronic, inflammatory disease associated with increased risk of cardiovascular (CV) disease. Arterial stiffness (AS) is an independent predictor of CV events. This study aimed to analyse local carotid AS parameters in seronegative and seropositive RA patients. Of 347 consecutive RA patients, we selected specifically those who were free of established CV diseases and risk factors. As a result, 140 patients (126 women, 52.2 ± 10 years) and 140 healthy controls (122 women, 52.7 ± 8.0 years) were enrolled into this study. The common carotid AS was evaluated using radio frequency echo-tracking system to determine the local carotid pulse wave velocity (cPWV) and carotid intima-media thickness (cIMT). Based on rheumatoid factor (RF) and/or anti-citrullinated protein antibody (ACPA) positivity, RA patients were categorized into seronegative and seropositive subgroups. Carotid PWV was determined to be significantly higher in all patients and subgroups than controls (p < .001 for all). Although cIMT was similar between the patients, controls and seropositive subgroup, seronegative patients had significantly higher cIMT compared to controls (p = .035) and seropositive group (p = .010). Moreover, a significant positive correlation was found between cPWV and age (r: 0.603, p < .001), ESR (r: 0.297, p = .004), ACPA (r: 0.346, p = .001) and cIMT (r: 0.290, p = .005) in seropositive patients. RA per se is sufficient to cause arteriosclerosis in the absence of classical CV risk factors. However, arterial hypertrophy is only increased in seronegative patients but not in seropositive group.

Toxoplasma gondii seroprevalence in pet cats in Norway and risk factors for seropositivity.

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Sævik, Bente Kristin; Krontveit, Randi Ingebjørg; Eggen, Kristine P; Malmberg, Nina; Thoresen, Stein I; Prestrud, Kristin W

2015-12-01

The aims of the study were to estimate Toxoplasma gondii seroprevalence in pet cats in Norway and to evaluate risk factors for seropositivity. Additionally, serum biochemistry and haematological variables for T gondii seropositive and seronegative cats were compared. A convenience sample of surplus sera submitted to the Central Laboratory, Norwegian University of Life Sciences, was collected. The samples were from healthy cats and cats with a variety of diseases. Analyses for IgG antibodies to T gondii were performed with a commercial direct agglutination test, with 1:40 as the threshold value. For risk factor analysis a logistic regression model of the relationship between predictors and the outcome was applied. One hundred and ninety-six of 478 cats were seropositive for T gondii, and the estimated seroprevalence in the study sample was 41.0% (95% confidence interval 36.6-45.4). Compared with domestic cats, pedigree cats had reduced risk for Toxoplasma seropositivity (odds ratio [OR] 0.42). Males had increased risk (OR 1.63) compared with females. The effect of age was highly significant, and an increase in the cats' age across the interquartile range (IQR; 52-160 months/4-13 years of age) doubled the risk of Toxoplasma seropositivity (OR 2.11). The risk for Toxoplasma seropositivity among cats living in Oslo was significantly reduced (OR 0.51) when compared with the rest of Norway. Pet cats in Norway appear to be commonly exposed to T gondii. Signalment and geographical region influenced the odds of Toxoplasma seropositivity, whereas health status did not. © ISFM and AAFP 2015.

Radiographic estimation in seropositive and seronegative rheumatoid arthritis.

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Sahatçiu-Meka, Vjollca; Rexhepi, Sylejman; Manxhuka-Kërliu, Suzana; Rexhepi, Mjellma

2011-08-01

Long since it have been suggested that a subpopulation of patients with rheumatoid arthritis, diagnosed with negative rheumatoid factor tests, represents a clinical entity quite distinct from that of seropositive rheumatoid arthritis (RA). Our aim was to establish a scientific comparative analysis between seronegative and seropositive rheumatoid arthritis, regarding some radiological and clinical parameters, applied for the first time on patients from Kosovo. Two hundred fifty patients with rheumatoid arthritis according to the American College of Rheumatology criteria were retrospectively studied by analysis the radiographic damage and clinical parameters of the disease, using a data base. All examinees were between 25-60 years of age (Xb=49.96, SD=10.37) with disease duration between 1-27 years (Xb = 6.41, SD=6.47). All patients underwent a standardised evaluation radiographs. Baseline standardised poster anterior radiographs of hands and feet and radiographs of other joints, depending on indications, were assessed. Erythrocyte sedimentation rate values correlated with the radiological damages and statistical difference was found for seronegative subset (r=0.24, p<0.01). Longer duration of the disease resulted in the increase of radiological changes in both subsets (r=0.66, p<0.01) seronegative, (r=0.49, p<0.01) seropositive. Anatomic changes of IInd and IIIrd level were nearly equally distributed in both subsets, 76 (60.8%) seronegative, 75 (60%) seropositive. Radiological damages are nearly equal in both subsets, elevate in relation to the duration of the disease and correlate with ESR values. Regarding the sero-status, differences within sex, with some exceptions, are not relevant. Although there are some definite quantitative and qualitative differences regarding sero-status, obviously there is a great deal of overlap between the two groups.

Radiographic estimation in seropositive and seronegative rheumatoid arthritis

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Vjollca Sahatçiu-Meka

2011-08-01

Full Text Available Long since it have been suggested that a subpopulation of patients with rheumatoid arthritis, diagnosed with negative rheumatoid factor tests, represents a clinical entity quite distinct from that of seropositive rheumatoid arthritis (RA. Our aim was to establish a scientific comparative analysis between seronegative and seropositive rheumatoid arthritis, regarding some radiological and clinical parameters, applied for the first time on patients from Kosovo. Two hundred fifty patients with rheumatoid arthritis according to the American College of Rheumatology criteria were retrospectively studied by analysis the radiographic damage and clinical parameters of the disease, using a data base. All examinees were between 25-60 years of age (Xb=49.96, SD=10.37 with disease duration between 1-27 years (Xb = 6.41, SD=6.47. All patients underwent a standardised evaluation radiographs. Baseline standardised poster anterior radiographs of hands and feet and radiographs of other joints, depending on indications, were assessed. Erythrocyte sedimentation rate values correlated with the radiological damages and statistical difference was found for seronegative subset (r=0.24, p<0.01. Longer duration of the disease resulted in the increase of radiological changes in both subsets (r=0.66, p<0.01 seronegative, (r=0.49, p<0.01 seropositive. Anatomic changes of IInd and IIIrd level were nearly equally distributed in both subsets, 76 (60.8% seronegative, 75 (60% seropositive. Radiological damages are nearly equal in both subsets, elevate in relation to the duration of the disease and correlate with ESR values. Regarding the sero-status, differences within sex, with some exceptions, are not relevant. Although there are some definite quantitative and qualitative differences regarding sero-status, obviously there is a great deal of overlap between the two groups.

Long-term MRI findings in neuromyelitis optica: seropositive versus seronegative patients.

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Kıyat-Atamer, A; Ekizoğlu, E; Tüzün, E; Kürtüncü, M; Shugaiv, E; Akman-Demir, G; Eraksoy, M

2013-05-01

Neuromyelitis optica (NMO) is a severe demyelinating inflammatory disorder associated with serum antibodies against aquaporin 4 (AQP4-Ab). A significant number of patients with NMO remain seronegative over time. Long-term observational magnetic resonance imaging (MRI) studies of the CNS in patients with NMO are rare or of limited duration. The objective of this study is to determine long-term MRI characteristics of seropositive and seronegative patients, and assess possible overlap with multiple sclerosis (MS). Clinical and radiological characteristics of 28 patients with NMO at onset and of 17 patients after an average follow-up time of 9 years were recorded. Fifty percent of patients were seropositive for AQP4-Ab. Onset and final brain/spinal MRI scans were retrospectively analysed and compared. Significantly more patients in the seronegative group had brain lesions at onset. Spinal lesions of seropositive patients were longer and showed increased cord swelling at onset MRI scans. After the follow-up time the differences between both groups disappeared. Patients in the seropositive group tended to develop brain lesions over time. No patient fulfilled Barkhof's or McDonald's radiological criteria for MS at onset or over time. Brain MRI features show differences between seropositive and seronegative patients at time of onset in NMO, but differences between groups vanish over time. None of the AQP4-negative patients fulfill radiological MS criteria on a long-term basis, suggesting that seronegative NMO constitutes an independent entity. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

Occurrence of oxidative stress in dairy cows seropositives for Brucella abortus.

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Perin, Géssica; Fávero, Juscivete F; Severo, Diego R T; Silva, Anielen D; Machado, Gustavo; Araújo, Hugo L; Lilenbaum, Walter; Morsch, Vera M; Schetinger, Maria Rosa C; Jordão, Ricardo S; Stefani, Lenita M; Bottari, Nathieli B; Da Silva, Aleksandro S

2017-09-01

Bovine brucellosis is an important zoonotic disease caused by the bacterium Brucella abortus that leads to economic losses due to animal discard and commercial restrictions. Since positive animals for brucellosis are culled, little is known about the pathogenesis of this disease. Therefore, the aims of this study were to evaluate possible changes in the activity of deaminase adenosine (ADA) and the oxidative stress in cows seropositives for brucellosis (Experiment I), and to evaluate the seroprevalence of B. abortus in dairy cows from the Western state of Santa Catarina, Southern Brazil (Experiment II). The Experiment I evaluated 20 pregnant cows: ten seropositives for B. abortus and ten seronegatives that were used as controls. The ADA activity and markers of oxidative stress (TBARS, catalase (CAT) and superoxide dismutase (SOD)) were evaluated in these animals. A reduction in the activity of ADA and catalase enzymes in seropositive animals was observed (p cows infected by B. abortus (p cows of 69 herds. The serodiagnosis was performed using two tests: buffered acidified antigen and 2-mercaptoethanol. However, none of the serum samples were positive for B. abortus. Although we did not find seropositive animals for brucellosis in our study, the disease still requires continued surveillance, due to its economic impact, and to the oxidative stress caused by it, which may have contributed to cases of abortion in three seropositive cows (Experiment I) in the final third of the gestation. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Psychosocial Integration of Seropositive Persons

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Matei Raluca

2017-05-01

Full Text Available We can assume without fail that the psychosocial implications in case of HIV/AIDS are as overwhelming as the medical aspects. For the positive person as well as for those who assist the seropositive people, the uncertainty frames the medical prognosis. All the effects that occur are entirely funded: the loss of self-trust as well as mistrusting others, stigmatization, isolation, getting abandoned by the family, friends, neighbors and school mates or coworkers. The current study aims to evaluate this aspect, the fact that the living environment of the seropositive person does not lead to significant differences as far as adjusting to HIV/AIDS diagnosis is concerned, but the adjusting differences are more related to the personality structure of the infected person, to the way this person identifies strategies of coping with the new situations he / she has to deal with (cognitive, emotional and behavioral strategies. In the applicative part of the study, we analyze the adjustment to the diagnosis, as well as the adherence to the treatment, by applying certain specific work instruments.

Coxiella burnetii seropositivity and associated risk factors in goats in Ontario, Canada.

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Meadows, S; Jones-Bitton, A; McEwen, S; Jansen, J; Menzies, P

2015-10-01

Coxiella burnetii is a zoonotic bacterium, and infection in goats with this bacterium can result in abortion, stillbirth or birth of non-viable kids. A cross-sectional study was conducted to identify the seroprevalence and risk factors for C. burnetii exposure in Ontario goats. Sera were collected between August 2010 and February 2012, and tested for C. burnetii specific antibodies using an enzyme-linked immunosorbent assay (IDEXX). Overall, 63.2% (48/76, 95% CI=51.9-73.4) of farms had one or more seropositive goats. A higher farm-level seroprevalence of 78.6% (33/42) was found on dairy goat farms, compared to 44.1% (15/34) on meat goat farms (pgoats were seropositive. Similarly, a higher individual-level seroprevalence was identified for dairy goats (43.7%, 633/1447) compared to meat goats (10.8%, 81/748) (pfarm-level clustering identified risk factors associated with seropositivity (pgoat farms were located in a 5-km radius, goats had 5.6 times (95% CI=1.01-30.8) times the odds of seropositivity compared to those that were not. Relative to goats from farms where all kidding pen hygiene was practiced (adding bedding, removing birth materials and disinfection after kidding), goats from farms which only added bedding and removed birth materials had a higher odds of seropositivity (OR=19.3, 95% CI=1.1-330.4), as did goats from farms which practiced none of these measures (OR=161.0, 95% CI=2.4-10822.2). An interaction term revealed kidding outdoors when there were no swine on farm had a protective effect on seropositivity compared to kidding indoors, or kidding outdoors with swine on the farm. These results can inform strategies to mitigate exposure to C. burnetii in Ontario. Copyright © 2015 Elsevier B.V. All rights reserved.

Risk Factors for Enterovirus A71 Seropositivity in Rural Indigenous Populations in West Malaysia.

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NikNadia, Nmn; Sam, I-Ching; Khaidir, Nasibah; Ngui, Romano; Lim, Yvonne A L; Goh, Xiang Ting; Choy, Seow Huey; Chan, Yoke Fun

2016-01-01

Enterovirus A71 (EV-A71), which is transmitted by the fecal-oral route, causes hand, foot and mouth disease and, rarely, severe neurological complications. In Malaysia, the indigenous rural community (Orang Asli) has a high prevalence of parasitic diseases due to poor sanitation, water supply and hygiene practices. This cross-sectional study compared the seroepidemiology of EV-A71 among rural Orang Asli and urban Kuala Lumpur populations in West Malaysia, and determined the risk factors associated with EV-A71 seropositivity in rural Orang Asli. Seropositive rates were determined by neutralization assay. EV-A71 seropositivity was strongly associated with increasing age in both populations. Rural Orang Asli children ≤12 years had significantly higher EV-A71 seropositivity rates than urban Kuala Lumpur children (95.5% vs 57.6%, P water (adjusted OR 6.2, 95% CI 2.3-16.6, P water may reduce the risk of EV-A71 infection. With significantly higher EV-A71 seropositive rates, younger rural children should be a priority target for future vaccination programs in Malaysia.

Increased inflammatory response in cytomegalovirus seropositive patients with Alzheimer's disease.

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Gabriel Westman

Full Text Available Alzheimer's disease (AD has been associated with increased local inflammation in the affected brain regions, and in some studies also with elevated levels of proinflammatory cytokines in peripheral blood. Cytomegalovirus (CMV is known to promote a more effector-oriented phenotype in the T-cell compartment, increasing with age. The aim of this study was to investigate the inflammatory response of peripheral blood mononuclear cells (PBMCs from AD patients and non-demented (ND controls. Using a multiplex Luminex xMAP assay targeting GM-CSF, IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IP-10 and TNF-α, cytokine profiles from PBMCs were analysed after stimulation with anti-CD3/CD28 beads, CMV pp65 peptide mix or amyloid β (Aβ protofibrils, respectively. CMV seropositive AD subjects presented with higher IFN-γ levels after anti-CD3/CD28 and CMV pp65 but not after Aβ stimulation, compared to CMV seropositive ND controls. When analysing IFN-γ response to anti-CD3/CD28 stimulation on a subgroup level, CMV seropositive AD subjects presented with higher levels compared to both CMV seronegative AD and CMV seropositive ND subjects. Taken together, our data from patients with clinically manifest AD suggest a possible role of CMV as an inflammatory promoter in AD immunology. Further studies of AD patients at earlier stages of disease, could provide better insight into the pathophysiology.

Seropositivity for Enterocytozoon bieneusi, Czech Republic

Czech Academy of Sciences Publication Activity Database

Sak, Bohumil; Kučerová, Z.; Kváč, Martin; Květoňová, Dana; Rost, M.; Secor, W. E.

2010-01-01

Roč. 16, č. 2 (2010), s. 335-337 ISSN 1080-6040 R&D Projects: GA AV ČR KJB500960701; GA ČR GP523/07/P117 Institutional research plan: CEZ:AV0Z60220518 Keywords : Enterocytozoon bieneusi * INTESTINAL MICROSPORIDIOSIS * seropositivity * human * DIARRHEA * SEROPREVALENCE Subject RIV: GJ - Animal Vermins ; Diseases , Veterinary Medicine Impact factor: 6.859, year: 2010

Adenovirus-36 Seropositivity and Its Relation with Obesity and Metabolic Profile in Children

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Isela Parra-Rojas

2013-01-01

Full Text Available The human adenovirus 36 (Ad-36 is causally and correlatively associated in animals and humans, respectively, with increased adiposity and altered metabolic profile. In previous studies, the relationship between Ad-36 seropositivity with obesity was established in adults and children. We evaluated the association of positive antibodies to Ad-36 with obesity and metabolic profile in Mexican children. Seventy-five children with normal-weight and 82 with obesity were studied in this research. All children had a clinic assessment which included weight, height, body circumferences, and skinfold thickness. Laboratory analyzes included triglycerides, total cholesterol, high-density lipoprotein, low-density lipoprotein, and glucose and insulin levels. An enzyme-linked immunosorbent assay (ELISA was used to determine the antibodies to Ad-36 in the serum samples. The overall Ad-36 seroprevalence was 73.9%. Ad-36 seropositivity had a higher prevalence in obese children than in normal weight group (58.6 versus 41.4%, P=0.007. Ad-36 seropositivity was associated with obesity (OR=2.66, P=0.01 and high-density lipoprotein <40 mg/dL (OR=2.85, P=0.03. The Ad-36 seropositive group had greater risk of 4 metabolic abnormalities compared with those children without none alteration. In summary, Ad-36 seropositivity was associated with obesity and low HDL-c levels in the sample of children studied.

The Seropositivity Rate of Atypical Agents in Patients with Community-Acquired Pneumonia

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Ruhan Karakoc Gunes

2007-08-01

Full Text Available The aim of this study was to investigate the IgM antibody positivities of atypical pneumonia agents in patients with community-acquired pneumonia (CAP, and to compare the results with controls. The serum samples which were collected from 87 adult patients and 21 healthy controls have been investigated by a commercial ELISA (Pneumobact ELISA IgM, Vircell, Spain in which four different atypical pneumonia agents were fixed onto a slide. In the patients group, IgM positivity rates for the agents were as follows, respectively; 2.3% for Legionella pneumophila, 56.3% Chlamydia pneumoniae, 33.3% for Mycoplasma pneumoniae, 9.2% for Coxiella burnetii. The rates of IgM positivities in the control group varied 7% for all of the agents except M. Pneumoniae and C. Pneumoniae and 2 of these controls were positive for L. Pneumophila IgM, one was positive for C. Burnetii IgM. According to the statistical evaluation, there were significant differences for IgM seropositivities to Mycoplasma pneumoniae and Chlamydia Pneumoniae,between the patient and the control groups (p0.05. We showed that the seropositivity rate of atypical agents in patients with CAP was significantly higher when compared to healthy control group. This result suggests us, atypical agents might be responsible in CAP patients in a great amount. Furthermore, our study also suggests that clinical and radiological findings are not useful for discriminating atypical from typical pneumonia. [TAF Prev Med Bull 2007; 6(4.000: 279-284

Prospective evaluation of human immunodeficiency virus-seropositive patients

International Nuclear Information System (INIS)

Post, M.J.D.; Berger, J.R.; Quencer, R.M.

1989-01-01

As part of a prospective longitudinal study of individuals who are human immunodeficiency virus (HIV) positive, cranial MR imaging was performed on 89 HIV-seropositive patients and correlated with clinical data. MR results were asymptomatics: MR images normal-58, abnormal-16; myelopathics: normal-seven, abnormal-four; encephalopathics: normal-three, abnormal-two. In asymptomatics, neurologic examination was positive in all with positive MR results but positive in only some with negative MR results. The authors concluded that MR imaging can show indirect evidence of HIV infection early in the disease, but abnormalities will be minor and seen only in the minority (21%) of symptomatics; these minor abnormalities may antedate clinical symptoms but not signs; an increase in severity of clinical disease correlates with increasingly severe atrophy and demyelination; and in some seropositives, whether asymptomatic or symptomatic, MR results remain normal

Risk Factors Associated with Brucella Seropositivity in Sheep and Goats in Duhok Province, Iraq

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Ali. G. Alhamada

2017-12-01

Full Text Available Sera from 432 small ruminants (335 sheep and 97 goats from 72 farms in Duhok Province, northern Iraq, were collected to investigate risk factors associated with brucellosis seropositivity. Serum samples were tested using the Rose Bengal test (RBT and an indirect enzyme-linked immunosorbent assay (iELISA. Using parallel interpretation, RBT and iELISA results showed that 31.7% (95% confidence interval (CI: 26.1, 36.3 of sheep and 34.0% (95% CI: 24.7, 44.3 of goats had antibodies against Brucella in the study area. A random-effects multivariable logistic regression model indicated that a higher chance of being seropositive (odds ratio (OR = 1.7; 95% 1.4; 2.2 was associated with an increase in the age of animals. The odds of Brucella seropositivity in flocks where sheep and goats grazed together was 2.0 times higher (95% CI: 1.08; 3.9 compared to flocks where sheep and goats grazed separately. The odds of Brucella seropositivity in small ruminants was 2.2 higher (95% CI: 1.2; 4.3 for animals originating from farms with a history of goat abortion in the preceding 12 months. In contrast, for every 1000 Iraqi Dinars (~0.85 US Dollar spent by the farmers on control of Brucella in their flocks, the odds of Brucella seropositivity decreased significantly (OR = 0.9, p-value = 0.021. The final model also indicated significant differences in Brucella seropositivity between the different districts of Duhok Province. This study provides a contribution to the epidemiology of brucellosis in small ruminants in northern Iraq.

Prevention of cervical cancer in HIV-seropositive women from developing countries: a systematic review protocol.

Science.gov (United States)

Mapanga, Witness; Elhakeem, Ahmed; Feresu, Shingairai A; Maseko, Fresier; Chipato, Tsungai

2017-04-24

Over 85% of cervical cancer cases and deaths occur in developing countries. HIV-seropositive women are more likely to develop precancerous lesions that lead to cervical cancer than HIV-negative women. However, the literature on cervical cancer prevention in seropositive women in developing countries has not been reviewed. The aim of this study is to systematically review cervical cancer prevention modalities available for HIV-seropositive women in developing countries. This protocol was developed by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement, and the systematic review will be reported in accordance with the PRISMA guidelines. Embase, MEDLINE, PubMed, CINAHL and Cochrane Library will be searched from inception up to date of final search, and additional studies will be located through citation and reference list tracking. Eligible studies will be randomised controlled trials, prospective and retrospective cohort studies, case-control and cross-sectional studies carried out in developing countries. Studies will be included if they are published in English and examine cervical cancer prevention modalities in HIV-seropositive women. Results will be summarised in tables and, where appropriate, combined using meta-analysis. This review will address the gap in evidence by systematically reviewing the published literature on the different prevention modalities being used to prevent cervical cancer in HIV-seropositive women in developing countries. The findings may be used to inform evidence-based guidelines for prevention of cervical cancer in seropositive women as well as future research. PROSPERO CRD42017054678 .

Predictive factors of cytomegalovirus seropositivity among pregnant women in Paris, France.

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Dieynaba S N'Diaye

Full Text Available Cytomegalovirus (CMV is the most frequent cause of congenital infection. The objective of this study was to evaluate predictive factors for CMV seronegativity in a cohort of pregnant women in Paris, France.Pregnant women enrolled in a prospective cohort during the 2009 A/H1N1 pandemic were tested for CMV IgG antibodies. Variables collected were age, geographic origin, lifestyle, work characteristics, socioeconomic status, gravidity, parity and number of children at home. A multivariate logistic regression model was used to identify independent predictive factors for CMV seropositivity.Among the 826 women enrolled, 389 (47.1% were primiparous, and 552 (67.1% had Metropolitan France as a geographic origin. Out of these, 355 (i.e. 57.0%, 95% confidence interval (CI: [53.6%-60.4%] were CMV seropositive: 43.7% (95% CI:[39.5%-47.9%] in those whose geographic origin was Metropolitan France and 84.1% in those with other origins (95% CI:[79.2%-88.3%]. Determinants associated with CMV seropositivity in a multivariate logistic regression model were: (i geographic origin (p<0.001(compared with Metropolitan France, geographic origins of Africa adjusted odds ratio (aOR 21.2, 95% CI:[9.7-46.5], French overseas departments and territories and other origin, aOR 7.5, 95% CI:[3.9-14.6], and Europe or Asia, aOR 2.2, 95% CI: [1.3-3.7]; and (ii gravidity (p = 0.019, (compared with gravidity = 1, if gravidity≥3, aOR = 1.5, 95% CI: [1.1-2.2]; if gravidity = 2, aOR = 1.0, 95% CI: [0.7-1.4]. Work characteristics and socioeconomic status were not independently associated with CMV seropositivity.In this cohort of pregnant women, a geographic origin of Metropolitan France and a low gravidity were predictive factors for CMV low seropositivity. Such women are therefore the likely target population for prevention of CMV infection during pregnancy in France.

Frequency of hepatitis B and C seropositivity in prisoners

International Nuclear Information System (INIS)

Fayyaz, M.; Qazi, M.A.

2006-01-01

This study was conducted on prisoners of Central Jail, Bahawalpur and on blood donors at Blood Bank Bahawal Victoria Hospital (BVD), Bahawalpur from 1st August 2005 to 30th November 2005. The intension was to study the sero prevalence of hepatitis Band C in prisoners and to note risk factor if any predisposing to the infection. All the prisoners of central jail Bahawalpur present during the study period, aged more than 18 years of either sex were included as the study group and a comparative group was blood donors presenting to blood bank BVH, Bahawalpur during this period. All the cases in study group (2086) as well as control group (9714) were screened for hepatitis B (HBs Ag) and hepatitis C (anti-HCV) infection detected on serum by One Step Test Device. All the positive cases were confirmed by Enzyme Linked Immunosorbent Assay. After an explanation, verbal consent was taken and a questionnaire was filled before taking samples from all the study group cases. On the basis of screening, prisoners were decided into seropositive group and sero-negative group. The different variable applied on both the groups were age, sex, occupation, residence, marital status, self shaving / by barber, family history of (H/o) jaundice, H/o blood trans-fusion, operation, tattooing and body piercing, drug abuse, same sex / extramarital sex and hepatitis B vaccination status. Total prisoners screened were 2086. Out of them 2072 were males (99.3%). Mean age was 34 years. Total seropositive cases were 249 (11.9%) While during the same period seropositivity in blood donors (control group) was 5.9%. Seropositivity of HBV was 5.6% in study group and 3.1% in control group (p<0.001), HCV was 6.3% Vs 2.8% (p<0.001), statistically very significant difference. Risk factors analysis among prisoners revealed that drug abuse was significantly associated with seropositivity (27% Vs 12%, p value <0.001). Among drug abusers, very high percentage of intravenous drug users was positive (89.2%, 25 out

Delayed LGI1 seropositivity in voltage-gated potassium channel (VGKC)-complex antibody limbic encephalitis.

Science.gov (United States)

Sweeney, Michael; Galli, Jonathan; McNally, Scott; Tebo, Anne; Haven, Thomas; Thulin, Perla; Clardy, Stacey L

2017-04-20

We utilise a clinical case to highlight why exclusion of voltage-gated potassium channel (VGKC)-complex autoantibody testing in serological evaluation of patients may delay or miss the diagnosis. A 68-year-old man presented with increasing involuntary movements consistent with faciobrachial dystonic seizures (FBDS). Initial evaluation demonstrated VGKC antibody seropositivity with leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) seronegativity. Aggressive immunotherapy with methylprednisolone and plasmapheresis was started early in the course of his presentation. Following treatment with immunotherapy, the patient demonstrated clinical improvement. Repeat serum evaluation 4 months posthospitalisation remained seropositive for VGKC-complex antibodies, with development of LGI1 autoantibody seropositivity. VGKC-complex and LGI1 antibodies remained positive 12 months posthospitalisation. Our findings suggest that clinical symptoms can predate the detection of the antibody. We conclude that when suspicion for autoimmune encephalitis is high in the setting of VGKC autoantibody positivity, regardless of LGI1 or CASPR2 seropositivity, early immunotherapy and repeat testing should be considered. 2017 BMJ Publishing Group Ltd.

Eco-epidemiological analysis of rickettsial seropositivity in rural areas of Colombia: A multilevel approach.

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Juan C Quintero V

2017-09-01

Full Text Available Rickettsiosis is a re-emergent infectious disease without epidemiological surveillance in Colombia. This disease is generally undiagnosed and several deadly outbreaks have been reported in the country in the last decade. The aim of this study is to analyze the eco-epidemiological aspects of rickettsial seropositivity in rural areas of Colombia where outbreaks of the disease were previously reported. A cross-sectional study, which included 597 people living in 246 households from nine hamlets in two municipalities of Colombia, was conducted from November 2015 to January 2016. The survey was conducted to collect sociodemographic and household characteristics (exposure data. Blood samples were collected to determine the rickettsial seropositivity in humans, horses and dogs (IFA, cut-off = 1/128. In addition, infections by rickettsiae were detected in ticks from humans and animals by real-time PCR targeting gltA and ompA genes. Data was analyzed by weighted multilevel clog-log regression model using three levels (person, household and hamlets and rickettsial seropositivity in humans was the main outcome. Overall prevalence of rickettsial seropositivity in humans was 25.62% (95%CI 22.11-29.12. Age in years (PR = 1.01 95%CI 1.01-1.02 and male sex (PR = 1.65 95%CI 1.43-1.90 were risk markers for rickettsial seropositivity. Working outdoors (PR = 1.20 95%CI 1.02-1.41, deforestation and forest fragmentation for agriculture use (PR = 1.75 95%CI 1.51-2.02, opossum in peridomiciliary area (PR = 1.56 95%CI 1.37-1.79 and a high proportion of seropositive domestic animals in the home (PR20-40% vs 40% vs <20% = 3.14 95%CI 2.43-4.04 were associated with rickettsial seropositivity in humans. This study showed the presence of Rickettsia antibodies in human populations and domestic animals. In addition, different species of rickettsiae were detected in ticks collected from humans and animals. Our results highlighted the role of domestic animals as sentinels of

HTLV-I/II and blood donors: determinants associated with seropositivity in a low risk population

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Bernadette Catalan Soares

2003-08-01

Full Text Available OBJECTIVE: Blood donors in Brazil have been routinely screened for HTLV-I/II since 1993. A study was performed to estimate the prevalence of HTLV-I/II infection in a low risk population and to better understand determinants associated with seropositivity. METHODS: HTLV-I/II seropositive (n=135, indeterminate (n=167 and seronegative blood donors (n=116 were enrolled in an open prevalence prospective cohort study. A cross-sectional epidemiological study of positive, indeterminate and seronegative HTLV-I/II subjects was conducted to assess behavioral and environmental risk factors for seropositivity. HTLV-I/II serological status was confirmed using enzyme-linked immunosorbent assay (EIA and Western blot (WB. RESULTS: The three groups were not homogeneous. HTLV-I/II seropositivity was associated to past blood transfusion and years of schooling, a marker of socioeconomic status, and use of non-intravenous illegal drugs. CONCLUSIONS: The study results reinforce the importance of continuous monitoring and improvement of blood donor selection process.

Seropositivity and determinants of immunoglobulin-G (IgG ...

African Journals Online (AJOL)

Background: This study is the first documented prevalence of IgG antibody against HSV-1&-2 in Port Harcourt, Nigeria and thus provides baseline data for future in-depth studies on HSV infection in South-South, Nigeria. Objective: This study determined the seropositivity and determinants of serum IgG antibody against ...

Isoniazid prophylactic therapy for tuberculosis in HIV-seropositive ...

African Journals Online (AJOL)

hypothetical cohort of 100 000 HIV-seropositive people in. South Africa over a ... health sector resources can be utilised in an optimal manner. This article ... second part we estimate the costs and benefits of isoniazid preventive ... The cohort was stratified into ... population risk of dying from any cause, the number of dual.

Seroprevalence and Risk Factors Associated with Seropositivity to Toxoplasma gondii among Stray and Domestic Cats (Felis silvestris catus

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Christel Bohn T. Garcia

2014-12-01

Full Text Available Toxoplasma gondii is a protozoan parasite that causes toxoplasmosis. It is widespread in the environment and infects a variety of warm-blooded animals, causing miscarriages and birth problems. Previous studies in the Philippines have determined the seropositivity of T. gondii in humans. However, the seroprevalence of the parasite among household pets, par ticularly its feline def initive host, remains insufficient . This study aimed to: (1 determine the seroprevalence of T. gondii antibodies among domestic and stray cats in the Philippines; and, (2 to analyze the risk factors associated with seropositivity. Blood samples from 59 domestic and stray cats were collected and tested for T. gondii seropositivity using a commercially available indirect ELISA kit, while pet owners and handlers were given questionnaires about their cats. Thirteen or 22.03% of the cats were seropositive to T. gondii, and risk factor analysis revealed a significant difference between domestic and stray cats with regard to diet (p = 0.026, OR = 8.333, c = 0.299 and domestication (p = 0.039, OR = 5.000, c = 0.276. Cats fed with table food tested 31.43% seropositive compared to the 4.35% of those fed with cat food, whereas 33.33% of the stray cats were seropositive compared to 7.69% for domestic cats. Odds ratio test showed that the risk factors studied were associated with higher likelihood of T. gondii seropositivity. These results implicate diet and environment in the transmission dynamics of T. gondii among cats.

Seroprevalence and Risk Factors for Leptospira Seropositivity in Beef Cattle, Sheep and Deer Farmers in New Zealand.

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Sanhueza, J M; Heuer, C; Wilson, P R; Benschop, J; Collins-Emerson, J M

2017-08-01

Leptospirosis is a global zoonosis that in New Zealand affects primarily people occupationally exposed to livestock. The objective of this study was to estimate the seroprevalence of five Leptospira serovars in farmers working on cattle, sheep and deer farms that had the serological status of animals previously assessed and to identify risk factors for farmer seropositivity. A total of 178 farmers from 127 properties participated in the study. Blood samples were tested using the microscopic agglutination test (MAT) for the presence of antibodies to Leptospira. Samples with a MAT titre ≥48 were considered seropositive. Using Bayesian statistical analysis, the median seroprevalence of Leptospira, all serovars combined, was estimated to be 6.6% (95% probability interval (PI) 3.6-10.9%). Risk factors associated with seropositivity were assisting deer or cattle calving, farming deer, having ≥25% of flat terrain and high abundance of wild deer on farm, while high possum abundance on farm was negatively associated with seropositivity. No association was observed between farmer serostatus and previously recorded livestock serology. Leptospira seropositivity was associated with influenza-like illness of farmers (RR = 1.7; 95% PI 1.0-2.5). Assuming a causal relationship, this suggested an annual risk of 1.3% (95% PI 0.0-3.0%) of influenza-like illnesses due to Leptospira infection in the population of farmers. The association between seropositivity and disease can be used to estimate the public health burden of leptospirosis in New Zealand. Identifying and understanding risk factors for Leptospira seropositivity can inform preventive measures, hence contributing to the reduction of leptospirosis incidence in farmers. © 2016 Blackwell Verlag GmbH.

Comparison of prevalence factors in horses with and without seropositivity to Neospora hughesi and/or Sarcocystis neurona.

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Pusterla, Nicola; Tamez-Trevino, Eva; White, Alexandria; Vangeem, Joshua; Packham, Andrea; Conrad, Patricia A; Kass, Philip

2014-05-01

Equine protozoal myeloencephalitis is a commonly diagnosed neurological disease of horses in North America and is caused by infection with Sarcocystis neurona or Neospora hughesi. The aim of this study was to compare prevalence factors among horses seropositive or seronegative to N. hughesi and/or S. neurona. A total of 3123 submissions were included in the study, with horses originating from 49 States. Thirty-eight animals from 21 States tested seropositive for N. hughesi only, 840 horses from 40 States were seropositive for S. neurona only, 25 horses from 14 States were seropositive for both protozoa, and 2220 horses from 49 States tested seronegative for both parasites. Significant associations were found between geographical location (State), month of submission, breed and serological status. Copyright © 2014 Elsevier Ltd. All rights reserved.

Vaccine Induced Antibody Response to Foot and Mouth Disease in Infectious Bovine Rhinotracheitis Seropositive Cattle

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Murat Şevik

2014-01-01

Full Text Available Foot and mouth disease (FMD and infectious bovine rhinotracheitis (IBR are two important infectious diseases of cattle. Inactivated FMD vaccines are the most powerful tools to protect animals against FMD. Previous studies showed that recombinant IBR-FMD viruses protected cattle from virulent BHV-1 challenge and induced protective levels of anti-FMDV antibodies. FMD is considered to be endemic in Turkey and inactivated oil adjuvanted vaccines are used for the immunization of cattle. Previous studies showed that seroprevalence of IBR in the Turkey’s dairy herd more than 50%. In this study, antibody response in IBR seropositive cattle following vaccination against FMD was investigated. IBR seropositive (n=208 and IBR seronegative (n=212 cattle were vaccinated with oil-adjuvanted bivalent vaccine (containing O1 Manisa, A22 Iraq FMDV strains. Solid-phase competitive ELISA (SPCE was used to measure antibodies produced in cattle. Protective level of antibody against serotype O was detected in 77.4% and serotypes A in 83.6% of IBR seropositive cattle. Protective level of antibody against serotype O antibody was detected in 49% and serotypes A in 66.9% of IBR seronegative cattle. The differences between the protection rates against both serotype O (P=0.0001 and serotype A (P=0.0001 in IBR seropositive and seronegative animals were statistically important (Fisher’s exact test, P<0.01. Results showed that after FMD vaccination, IBR seropositive animals produced high titres of antibodies than seronegative animals.

Feline Toxoplasmosis: Tumor Necrosis Factor, Nitric Oxide, and Free Radicals in Seropositive Cats.

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Faria, Joice L M; Couto, Caroline do; Wierzynski, Sheron L; Bottari, Nathieli B; Baldissera, Matheus D; Pereira, Wanderson A B; Da Silva, Aleksandro S

2018-02-01

Toxoplasma gondii is a cosmopolitan protozoan that causes disease in several species, including humans. In cats, these infections are usually asymptomatic, but in other species they can lead to high levels of inflammatory and cell damage markers, causing cellular damage. Therefore, the aim of this study was to measure levels of tumor necrosis factor (TNF-α), reactive oxygen species (ROS), and nitric oxide (nitrite/nitrate-NO x ) in the serum of cats seropositive for T. gondii. Initially, we investigated the presence of antibodies against T. gondii in cats in the city of Concordia, Santa Catarina, Brazil, with the use of indirect immunofluorescence (IFA), and found 30 cats seropositive for T. gondii and 30 seronegative cats. In this study, seropositive cats showed higher levels of TNF-α, ROS, and NO x compared to seronegative cats. Although cats do not show clinical signs of disease, constant inflammatory response can cause cell damage, which over time may adversely affect the animal.

Comparison of seronegative and seropositive rheumatoid arthritis with regard to some clinical characteristics.

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Sahatçiu-Meka, Vjollca; Izairi, Remzi; Rexhepi, Sylejman; Manxhuka-Kerliu, Suzana

2009-01-01

The aim of this study is to establish a scientific comparative analysis between seronegative and seropositive rheumatoid arthritis (RA), with regard to some clinical characteristics. The studied group consisted of RA seronegative patients with titters lower then 1:64 defined by Rose-Waaler test, while the control group consisted of RA seropositive patients with titters of 1:64 or higher. Examinees all belonged to the 2nd and 3rd functional classes according to ARA criteria, were between 25-60 years of age (Xb = 49.96), with disease duration between 1-27 years (Xbox = 6.41). In the disease onset most frequently affected joints were metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joint of the hands, almost equally represented with regard to sero-status and sex. During the examination seropositive patients showed a higher presence of inflamation of peripheral joints of hand and foot, but only the presence of PIP of the hands was statistically significant (chi2 = 15.63, p < 0.01). Knees, talocrural joints and elbows were more frequently affected in seropositive patients, whereas humeroscapular, coxofemoral and sacroiliacal joints were more frequently affected in seronegative patients, but without significant statistical difference with regard to sero-status. The presence of affected PIP of the hands (chi2 = 9.96, p < 0.01) and knees (chi2 = 4.17, p < 0.05) with regard to sex was statistically significant in seropositive female patients, as well as the presence of atacked PIP of the hands (chi2 = 6.08, p < 0.05), and cervical vertebrae (chi2 = 6.00, p < 0.05) in seropositive male patients. There were some differences between groups with regard to sex in metatarsophalangealjoints (MTP), PIP of the foot, and other joints, but without any statistical significance. In both subsets statistically significant domination was found in affected second (chi2 = 20.85, p < 0.01) and third (chi2 = 15.70, p < 0.01) fingers of the PIP level of hands and third finger (chi2

Cultural Influences on Hepatitis B Surface Antigen Seropositivity in ...

African Journals Online (AJOL)

Objective: To determine the role of cultural influences, namely: circumcision, ear piercing and traditional scarification, on HbsAg seropositivity among primary school children in Nnewi. Subjects and Method: Two hundred and thirty seven randomly selected primary school children aged 5-12 years, were screened for HbsAg.

Incidence of seropositive myasthenia gravis in Cape Town and ...

African Journals Online (AJOL)

Background. Myasthenia gravis (MG) is a treatable autoimmune disease characterised by fatiguable weakness of skeletal muscles. More than 85% of MG patients have antibodies to the acetylcholine receptor (AChR) at the neuromuscular junction or are seropositive for MG (SPMG). In the developed world the incidence of ...

Household prevalence of seropositivity for Trypanosoma cruzi in three rural villages in northwest Argentina: environmental, demographic, and entomologic associations.

Science.gov (United States)

Gürtler, R E; Chuit, R; Cécere, M C; Castañera, M B; Cohen, J E; Segura, E L

1998-11-01

Environmental, demographic, and entomologic variables were analyzed by logistic multiple regression analysis for their association with the likelihood of being seropositive for Trypanosoma cruzi in three highly infested rural villages of northwest Argentina. The prevalence of seropositivity for T. cruzi, as determined by the composite results of three serologic tests, was 34% among 338 persons in 1992. The strongest positive predictors of the adjusted odds of being infected were the household number of dogs, the density of T. cruzi-infected Triatoma infestans in bedroom areas, and each person's age. Dwellers from houses with roofs made completely or partly with a grass called simbol, or which used insecticides rudimentarily and nonsystematically, had a significantly lower odds of being seropositive for T. cruzi than residents from other types of dwellings. The adjusted odds of infection also increased with the number of T. cruzi-infected dogs or cats and the presence of chickens in bedroom areas. No significant effects on the adjusted odds of infection of a community-wide deltamethrin spraying carried out in one of the villages seven years before were detected. Socioeconomic indicators, such as domiciliary area, and numbers of corrals and livestock, were inversely related to being infected. Our study identified several manageable variables suitable for control actions, most of them not examined before in univariate or multivariate analyses. Environmental management based on low-cost housing with appropriate local materials and removal of domestic animals from domiciliary areas have a crucial role to play in the control of Chagas' disease in rural areas.

Associations Between Neighborhood Characteristics, Social Cohesion, and Perceived Sex Partner Risk and Non-Monogamy Among HIV-Seropositive and HIV-Seronegative Women in the Southern U.S.

Science.gov (United States)

Haley, Danielle F; Wingood, Gina M; Kramer, Michael R; Haardörfer, Regine; Adimora, Adaora A; Rubtsova, Anna; Edmonds, Andrew; Goswami, Neela D; Ludema, Christina; Hickson, DeMarc A; Ramirez, Catalina; Ross, Zev; Bolivar, Hector; Cooper, Hannah L F

2018-07-01

Neighborhood social and physical factors shape sexual network characteristics in HIV-seronegative adults in the U.S. This multilevel analysis evaluated whether these relationships also exist in a predominantly HIV-seropositive cohort of women. This cross-sectional multilevel analysis included data from 734 women enrolled in the Women's Interagency HIV Study's sites in the U.S. South. Census tract-level contextual data captured socioeconomic disadvantage (e.g., tract poverty), number of alcohol outlets, and number of non-profits in the census tracts where women lived; participant-level data, including perceived neighborhood cohesion, were gathered via survey. We used hierarchical generalized linear models to evaluate relationships between tract characteristics and two outcomes: perceived main sex partner risk level (e.g., partner substance use) and perceived main sex partner non-monogamy. We tested whether these relationships varied by women's HIV status. Greater tract-level socioeconomic disadvantage was associated with greater sex partner risk (OR 1.29, 95% CI 1.06-1.58) among HIV-seropositive women and less partner non-monogamy among HIV-seronegative women (OR 0.69, 95% CI 0.51-0.92). Perceived neighborhood trust and cohesion was associated with lower partner risk (OR 0.83, 95% CI 0.69-1.00) for HIV-seropositive and HIV-seronegative women. The tract-level number of alcohol outlets and non-profits were not associated with partner risk characteristics. Neighborhood characteristics are associated with perceived sex partner risk and non-monogamy among women in the South; these relationships vary by HIV status. Future studies should examine causal relationships and explore the pathways through which neighborhoods influence partner selection and risk characteristics.

Comparative analysis of seronegative and seropositive rheumatoid arthritis regarding some epidemiological and anamnestic characteristics.

Science.gov (United States)

Sahatçiu-Meka, Vjollca; Izairi, Remzi; Rexhepi, Sylejman; Manxhuka-Kerliu, Suzana

2007-01-01

Classifying patients into two subsets of the disease--seronegative RA and seropositive RA--has been the subject of many studies which aim to clarify this phenomenon--without any conclusive or acceptable answer so far. The aim of this prospective study was to establish a scientific comparative analysis between seronegative and seropositive rheumatoid arthritis (RA) regarding some epidemiological and anamnestic characteristics. The studied group consisted of seronegative patients with titers lower than 1:64 as defined by Rose-Waaler test, while the control group consisted of seropositive patients with titers of 1:64 or higher. All patients belonged to 2nd and 3rd functional class according to the ARA criteria, were between 25-60 years of age (Xb=49.96), with disease duration between 1-27 years (Xb=6.41). Education, residence, economic and living conditions did not show any significant statistical difference regarding serostatus. Familial clustering of RA confirmed higher susceptibility in the seropositive group (chi2=7.02; p<0.01). In both subsets banal diseases, psychic and physical trauma, weakness, and numbness of hands and legs dominated, without any statistical differenceregarding serostatus. Some differences between groups regarding sex were noticed, but were not statistically significant, except regarding physical trauma, which was more present in seronegative females (chi2=8.05; p<0.01).

Gastrointestinal and urinary tract pathogenic infections among HIV seropositive patients at the Komfo Anokye Teaching Hospital in Ghana.

Science.gov (United States)

Boaitey, Yaw Agyekum; Nkrumah, Bernard; Idriss, Ali; Tay, Samuel Crowther Kofi

2012-08-21

Gastrointestinal and urinary tract pathogenic infections are aggravating the incidence and progression of the Human Immunodeficiency Virus (HIV) infection into Acquired Immune Deficiency Syndrome (AIDS) more especially in the developing countries. This study was conducted to assess the common gastrointestinal and urinary infections among HIV/AIDS patients at the Komfo Anokye Teaching Hospital (KATH) in Ghana between April and December 2008. This work reports on gastrointestinal and urinary tract pathogenic infections among 500 HIV seropositive and 300 HIV seronegative patients. There was a 35% (175/500) prevalence of intestinal parasites among HIV seropositive patients compared to 4.3% (13/300) in HIV seronegative patients. Giardia lamblia and Cryptosporidium accounted for 19% (95/500) and 14% (70/500) respectively, while Schistosoma mansoni, Strongyloides stercoralis and hookworm together accounted for 2% (10/500) of intestinal parasitic infections among the HIV seropositive patients. There was no significant difference (p > 0.05) in urinary parasitic infection between HIV seropositive 1% (2/500) and seronegative patients 0.7% (2/300). Most, 60 (86%) out of 70, of the urinary tract infection among the HIV seropositive patients was due to bacteria with E. coli being the most predominant isolate, 28 (47%) out of 60. There was no significant difference in infections based on age and gender. G. lamblia and Cryptosporidium were the most common gastrointestinal parasites detected while bacteria accounted for majority of the urinary tract infections among the HIV seropositive patients at the hospital.

Clinical presentation and opportunistic infections in HIV-1, HIV-2 and HIV-1/2 dual seropositive patients in Guinea-Bissau

DEFF Research Database (Denmark)

Sørensen, Allan; Jespersen, Sanne; Katzenstein, Terese L

2016-01-01

HIV-2 is prevalent. In this study, we aimed to characterize the clinical presentations among HIV-1, HIV-2 and HIV-1/2 dual seropositive patients. Methods: In a cross-sectional study, newly diagnosed HIV patients attending the HIV outpatient clinic at Hospital Nacional Sim~ao Mendes in Guinea......-Bissau were enrolled. Demographical and clinical data were collected and compared between HIV-1, HIV-2 and HIV-1/2 dual seropositive patients. Results: A total of 169 patients (76% HIV-1, 17% HIV-2 and 6% HIV 1/2) were included in the study between 21 March 2012 and 14 December 2012. HIV-1 seropositive...... antigen. Conclusion: HIV-1 and HIV-1/2 seropositive patients have lower CD4 cell counts than HIV-2 seropositive patients when diagnosed with HIV with only minor clinical and demographic differences among groups. Few patients were diagnosed with TB and cryptococcal disease was not found to be a major...

Survival time and effect of selected predictor variables on survival in owned pet cats seropositive for feline immunodeficiency and leukemia virus attending a referral clinic in northern Italy.

Science.gov (United States)

Spada, Eva; Perego, Roberta; Sgamma, Elena Assunta; Proverbio, Daniela

2018-02-01

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are among the most important feline infectious diseases worldwide. This retrospective study investigated survival times and effects of selected predictor factors on survival time in a population of owned pet cats in Northern Italy testing positive for the presence of FIV antibodies and FeLV antigen. One hundred and three retrovirus-seropositive cats, 53 FIV-seropositive cats, 40 FeLV-seropositive cats, and 10 FIV+FeLV-seropositive cats were included in the study. A population of 103 retrovirus-seronegative age and sex-matched cats was selected. Survival time was calculated and compared between retrovirus-seronegative, FIV, FeLV and FIV+FeLV-seropositive cats using Kaplan-Meier survival analysis. Cox proportional-hazards regression analysis was used to study the effect of selected predictor factors (male gender, peripheral blood cytopenia as reduced red blood cells - RBC- count, leukopenia, neutropenia and lymphopenia, hypercreatininemia and reduced albumin to globulin ratio) on survival time in retrovirus-seropositive populations. Median survival times for seronegative cats, FIV, FeLV and FIV+FeLV-seropositive cats were 3960, 2040, 714 and 77days, respectively. Compared to retrovirus-seronegative cats median survival time was significantly lower (P<0.000) in FeLV and FIV+FeLV-seropositive cats. Median survival time in FeLV and FIV+FeLV-seropositive cats was also significant lower (P<0.000) when compared to FIV-seropositive cats. Hazard ratio of death in FeLV and FIV+FeLV-seropositive cats being respectively 3.4 and 7.4 times higher, in comparison to seronegative cats and 2.3 and 4.8 times higher in FeLV and FIV+FeLV-seropositive cats as compared to FIV-seropositive cats. A Cox proportional-hazards regression analysis showed that FIV and FeLV-seropositive cats with reduced RBC counts at time of diagnosis of seropositivity had significantly shorter survival times when compared to FIV and FeLV-seropositive

Seropositive pigs to Toxoplasma gondii (Apicomplexa: Toxoplasmatinae sent to slaughter and destined for human consumption

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Wanderley M. de Almeida

2015-12-01

Full Text Available ABSTRACT. de Almdeida W., Miranda Z.B., Flausino W., Coelho C.D., Fonseca A.B.M. & Lopes C.W.G. [Seropositive pigs to Toxoplasma gondii (Apicomplexa: Toxoplasmatinae sent to slaughter and destined for human consumption.] Suínos sororreagentes a Toxoplasma gondii (Apicomplexa: Toxoplasmatinae enviados para abate e destinados ao consumo humano. Revista Brasileira de Medicina Veterinária, 37(4:397-400, 2015. Curso de Pós-Graduação em Medicina Veterinária - Higiene Veterinária e Processamento Tecnológico de Produtos de Origem Animal, Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brasil Filho, 64, Vital Brazil, Niterói, RJ 24230-340, Brasil. E-mail: wanderleyma@yahoo.com.br This study aimed to determine the frequency of pigs seropositive to Toxoplasma gondii by indirect immunofluorescence assay with cutoff 1:16. Of blood samples collected at slaughter, 250 of them were from animals raised in the State of Minas Gerais; while 181 were from the State of Rio de Janeiro with a total of 431 examined samples. Of these, 19/250 (4.41% of MG and 39/181 (9.04% of RJ, determining a total of 13.45% seropositive animals. Regardless of slaughter be under the control of the inspection service, the precedence of the animals was highly significant (p = 0.0001 in the number of seropositive animals. Although the percentage of seropositive animals to T. gondii from both regions studied in this work, and from the point of view of a public health problem, pork and its frescal type products may continue to be considered as a source of infection of this coccidia for humans, if they are consumed as raw or undercooked.

TOXOPLASMOSIS: MORPHOLOGICAL AND MORPHOMETRIC EVALUATION OF SPINAL CORD NEURONS FROM NONSYMPTOMATIC SEROPOSITIVE DOGS

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Alessandra Cristina Francischini de Carvalho

2015-04-01

Full Text Available The aim of this work was to analyze the neuron morphology and morphometry of cervical, thoracic and lumbar areas of nonsymptomatic seropositive dogs’ spinal cord for toxoplasmosis. Twenty indefinite-breed adult dogs were used; ten dogs were healthy, with negative serology for toxoplasmosis, and were used as the control group (group 1, and ten dogs were nonsymptomatic but seropositive for toxoplasmosis (group 2. After the microtomy, with interval of 100 micrometers (µm, the histological 5-µm-thick cuts were dyed by hematoxylin-eosin and Masson's trichrome techniques. The glass slides were analyzed under light microscope to examine the neuron morphology. The parameters considered for the morphometric analysis were area, perimeter, maximum diameter, minimum diameter and shape factor of cytoplasm and nucleus of neuron. The results were statistically analyzed by Student’s t test at 5% probability level. The morphological characteristics between the two groups were similar and according to literature. The morphometric results showed that there were changes in neurons size and structure, and increase and loss of star shape were noticed in seropositive animals. The results suggest that the neurons of these dogs, yet nonsymptomatic, can have lost their conductor function.

Radiographic visualisation of seropositive rheumatoid arthritis in Carriers of HLA-B27

International Nuclear Information System (INIS)

Jurik, A.G.; Carvalho, A. de; Graudal, H.; Aarhus Univ.

1987-01-01

A group of 11 B27-positive, seropositive patients with rheumatoid arthritis was compared with 11 matched B27-negative seropositive patients. The radiographs of all limb joints, the sacroiliac joints, and the cervical spine were read blindly. Ten patients in each group were radiographed 2-6 times during observation periods of 3-13 years; one patient in each group was only examined once. The prevailing picture of both groups was that of progressive erosive rheumatoid arthritis, although two small differences were found: Erosions of the apophyseal joints of the cervical spine and slight periosteal new bone formation of the shoulder, hip, and knee regions occurred more often in the B27-positive than in the B27-negative group. (orig.) [de

The Rate of Helicobacter pylori Seropositivity in a Group of Korean Patients with HLA-B27-Associated Acute Anterior Uveitis.

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Jeong Hun Bae

Full Text Available To investigate an association between Helicobacter pylori seropositivity and HLA-B27-positive acute anterior uveitis (AAU in Korean patients.Retrospective analysis was performed with data from 106 patients previously diagnosed with AAU without clinical evidence of spondyloarthropathy. Serum immunoglobulin G antibodies to H. pylori were measured by enzyme-linked immunosorbent assay, and HLA typing was performed using polymerase chain reaction of DNA amplification. We included 72 non-uveitis patients and 35 age- and sex-matched healthy controls in the study.Of the 106 patients with AAU, 41 (38.7% were HLA-B27-positive, and 45 (42.5% were seropositive for H. pylori. Patients with HLA-B27-positive AAU had a significantly lower prevalence of H. pylori seropositivity compared to those with HLA-B27-negative AAU and healthy controls (24.4% vs. 53.8%, p = 0.003; 24.4% vs. 57.1%, p = 0.004, respectively. In the non-uveitis group, however, HLA-B27-positive patients exhibited similar H. pylori seropositivity prevalence to HLA-B27-negative patients and healthy controls (45.5% vs. 55.7%, p = 0.529; 45.5% vs. 57.1%, p = 0.497, respectively. In multivariate analysis, a low prevalence of H. pylori seropositivity was significantly associated with HLA-B27-positive AAU (odds ratio = 0.340, 95% confidence interval 0.135-0.855, p = 0.022.Our results suggest an inverse association between H. pylori seropositivity and HLA-B27-positive AAU. Further investigation of this association is needed, given the low prevalence of H. pylori seropositivity observed in patients with HLA-B27-positive AAU.

Features of anti-aquaporin 4 antibody-seropositive Chinese patients with neuromyelitis optica spectrum optic neuritis.

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Li, Hongyang; Wang, Yanling; Xu, Quangang; Zhang, Aidi; Zhou, Huanfen; Zhao, Shuo; Kang, Hao; Peng, Chunxia; Cao, Shanshan; Wei, Shihui

2015-10-01

The detection of anti-aquaporin-4 autoantibody (AQP-4 Ab) is crucial to detect patients who will develop neuromyelitis optica (NMO); however, there are few studies on the AQP-4 Ab serostatus of patients with neuromyelitis optica spectrum ON. We analyzed the clinical and paraclinical features of neuromyelitis optica spectrum ON patients in China according to the patients' AQP4-Ab serostatus. 125 patients with recurrent and bilateral ON with simultaneous attacks were divided into AQP-4 Ab-seropositive and -seronegative groups. Demographic, clinical, serum autoantibody data, connective tissue disorders (CTDs), visual performance were compared. A Visual Acuity (VA) of less than 0.1 during acute ON attacks occurred more frequently in the seropositive group (p = 0.023); however, there was not a significant difference between groups on VA recovery after the first attack. The seropositive group experienced the worst outcome during the last attack (p = 0.017). Other co-existing autoimmunity antibodies (p optica spectrum ON.

Epidemiological profile of seropositive blood donors at a tertiary care hospital in North India

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Jency Maria Koshy

2014-01-01

Full Text Available Background: Transfusion-transmissible infections HIV, HBV, and HCV are among the greatest threats to blood safety for transfusion recipients. Seroprevalence among blood donors is a useful source of information on their prevalence in the community. The present study was undertaken to determine the profile of the seropositive blood donors attending the blood bank at Christian Medical College, Ludhiana, Punjab. Materials and Methods: This was a 3-year cross-sectional study, (1 st January 2008 till 31 st December 2010 whereby the data of the blood donors screened during this time were analyzed. We further studied the epidemiological profile of the seropositive donors. Results: There were a total of 32,829 donations. Seroprevalence of HIV, HBV, and HCV were 0.27%, 1.11% and 1.53%, respectively. Most of them were males (96.76% and were in the age group of 18-30 years. Replacement donors constituted 95.75%. Occupation of seropositive donors included business, various services, and agriculture. There were 89 students who were seropositive. Conclusions: Seroprevalence among blood donors has shown a significant (P value for HIV 0.05, HBV < 0.001, HCV 0.004 decreasing trend over the 3 years. The professional distribution reveals the shift in seroprevalence from the high-risk group to the general population. Introducing pre test and post test counselling in blood banks will identify patients at an earlier stage where treatment would be more effective. The need to shift the burden to voluntary blood donation cannot be overemphasised.

Latiglutenase Improves Symptoms in Seropositive Celiac Disease Patients While on a Gluten-Free Diet.

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Syage, Jack A; Murray, Joseph A; Green, Peter H R; Khosla, Chaitan

2017-09-01

Celiac disease (CD) is a widespread condition triggered by dietary gluten and treated with a lifelong gluten-free diet (GFD); however, inadvertent exposure to gluten can result in episodic symptoms. A previous trial of latiglutenase (clinicaltrials.gov; NCT01917630), an orally administered mixture of two recombinant gluten-specific proteases, was undertaken in symptomatic subjects with persistent injury. The primary endpoint for histologic improvement was not met, presumably due to a trial effect. In this post hoc analysis, we investigated the efficacy of latiglutenase for reducing symptoms in subgroups of the study participants based on their seropositivity. The study involved symptomatic CD patients following a GFD for at least one year prior to randomization. Patients were treated for 12 weeks with latiglutenase or placebo. Of 398 completed patients, 173 (43%) were seropositive at baseline. Symptoms were recorded daily, and weekly symptom scores were compiled. p values were calculated by analysis of covariance. A statistically significant, dose-dependent reduction was detected in the severity and frequency of symptoms in seropositive but not seronegative patients. The severity of abdominal pain and bloating was reduced by 58 and 44%, respectively, in the cohort receiving the highest latiglutenase dose (900 mg, n = 14) relative to placebo (n = 54). Symptom improvement increased from week 6 to week 12. There was also a trend toward greater symptom improvement with greater baseline symptom severity. Seropositive CD patients show symptomatic improvement from latiglutenase taken with meals and would benefit from the availability of this treatment.

Factors associated with syphilis seropositive and Human Immunodeficiency Virus (HIV) infection among inmates at Lubuk Pakam prison, Indonesia

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Sembiring, E.; Ginting, Y.; Saragih, R. H.

2018-03-01

Syphilis has been known to increase the risk of acquiring or transmitting HIV infection. Epidemiologic studies showed that HIV transmission is 3-5 times higher in people with syphilis.Hence, in this current study, the factors associated with syphilis-seropositive and HIV infection were evaluated.This study used cross-sectional study. This study included inmates at Lubuk Pakam prison in November 2016. After interviewing participants’ demographics and risk behaviors, blood samples were obtained to be tested for HIV and syphilis, using the Rapid Test tool of HIV 3 methods and One STEP Syphilis Anti TP-Test. A total number of 1,114 inmates were included in this study, consisted of 1,081 male (97%) and 33female (3%). Ten inmates were HIV-positive (0.9%), whereas 70 inmates were syphilis-seropositive (6.3%).Based on multivariate-analyses, high-risk sexual behaviors associated with the increased risk of syphilis-seropositive of up to 8.31 times (p=0.002). HIV status also portrayed higher risk of syphilis-seropositive compared to non-HIV participants (3.98 fold, p=0.019). In HIV incidence, found that high-risk sexual behaviors also significantly increased the risk of HIV (7.69 fold, p=0.003). Syphilis-seropositive was also highly associated with HIV risk (5.09 fold, p=0.019).Syphilis and HIV showed a close association with several shared contributing factors.

Serotonin modulates immune function in T cells from HIV-seropositive subjects

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Eugen-Olsen, J; Afzelius, P; Andresen, L

1997-01-01

We have shown earlier increased intracellular levels of cAMP in peripheral lymphocytes from HIV-seropositive subjects and that a chemically induced decrease in this level increases cell proliferation and cytotoxicity. Others have shown that serotonin indirectly decreases intracellular cAMP levels...

Household Socioeconomic and Demographic Correlates of Cryptosporidium Seropositivity in the United States.

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Daniel J Becker

Full Text Available Cryptosporidium are parasitic protozoa that infect humans, domestic animals, and wildlife globally. In the United States, cryptosporidiosis occurs in an estimated 750,000 persons annually, and is primarily caused by either of the Cryptosporidium parvum genotypes 1 and 2, exposure to which occurs through ingestion of food or water contaminated with oocytes shed from infected hosts. Although most cryptosporidiosis cases are caused by genotype 1 and are of human origin, the zoonotic sources of genotype 2, such as livestock, are increasingly recognized as important for understanding human disease patterns. Social inequality could mediate patterns of human exposure and infection by placing individuals in environments where food or water contamination and livestock contact is high or through reducing the availability of educational and sanitary resources required to avoid exposure.We here analyzed data from the National Health and Nutritional Examination Survey (NHANES between 1999 and 2000, and related seropositivity to Cryptosporidium parvum to correlates of social inequality at the household and individual scale. After accounting for the complex sampling design of NHANES and confounding by individual demographics and household conditions, we found impaired household food adequacy was associated with greater odds of Cryptosporidium seropositivity. Additionally, we identified individuals of non-white race and ethnicity and those born outside the United States as having significantly greater risk than white, domestic-born counterparts. Furthermore, we provide suggestive evidence for direct effects of family wealth on Cryptosporidium seropositivity, in that persons from low-income households and from families close to the poverty threshold had elevated odds of seropositivity relative to those in high-income families and in households far above the poverty line.These results refute assertions that cryptosporidiosis in the United States is independent of

Periodontal status and dental care in HIV seropositive patients

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Maria Sueli Marques Soares

2009-12-01

Full Text Available Objective: The aim of the study was to evaluate the correlation between CD4+ cell count and viral load with periodontal and dental status in HIV seropositive patient. Methods: Forty HIV seropositive patients were selected from the dental clinic of the Clementino Fraga Hospital in João Pessoa, Paraíba, Brazil. The Community Periodontal Index, Simplified Oral Hygiene Index and Decayed, Missing or Filled Teeth Index were determined. The values of CD4+ lymphocyte count and viral load were collected from the medical records. Descriptive analysis was made and Spearman’s correlation test was applied, with values of p<0.05 being significant. Results: HIV seropositive patients were aged 33 to 47 years (mean = 40 years, 26 were men and 14 women. The mean CD4+ lymphocyte count was 507.82±306.4 cells/mm3, with 41% being a high, 38.5% a medium and 20.5% a low level. Sixty-five percent of the patients had undetectable viral load, 12.5% had a high, 5% a low and 5% a medium viral load. Most patients (87.5% presented with periodontal disease, calculus was the most frequent condition (40%. The mean Decayed, Missing or Filled Tooth Index was 19.7±6.8, with prevalence of the missing component. There was significant statistical correlation between the CD4+ count and the periodontal condition, p=0.046. There was no significant correlation between the CD4+ count and the Decayed, Missing or Filled Teeth Index (p=0.469 and the Simplified Oral Hygiene Index (p=0.189 indexes, and between viral load and Decayed, Missing or Filled Teeth Index (p=0.452, the Simplified Oral Hygiene Index (p=0.158 and Community Periodontal Index (p=0.216. Conclusion: The periodontal condition was influenced to a greater by the CD4+ cell count than the viral load, while there was no correlation between the decayed condition and the CD4+ cell count or the viral load condition.

Seroprevalences of feline leukemia virus and feline immunodeficiency virus infection in cats in the United States and Canada and risk factors for seropositivity.

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Burling, Amie N; Levy, Julie K; Scott, H Morgan; Crandall, Michael M; Tucker, Sylvia J; Wood, Erin G; Foster, Jessie D

2017-07-15

OBJECTIVE To estimate seroprevalences for FeLV antigen and anti-FIV antibody and risk factors for seropositivity among cats in the United States and Canada. DESIGN Cross-sectional study. ANIMALS 62,301 cats tested at 1,396 veterinary clinics (n = 45,406) and 127 animal shelters (16,895). PROCEDURES Blood samples were tested with a point-of-care ELISA for FeLV antigen and anti-FIV antibody. Seroprevalence was estimated, and risk factors for seropositivity were evaluated with bivariate and multivariable mixed-model logistic regression analyses adjusted for within-clinic or within-shelter dependencies. RESULTS Overall, seroprevalence was 3.1% for FeLV antigen and 3.6% for anti-FIV antibody. Adult age, outdoor access, clinical disease, and being a sexually intact male were risk factors for seropositivity for each virus. Odds of seropositivity for each virus were greater for cats tested in clinics than for those tested in shelters. Of 1,611 cats with oral disease, 76 (4.7%) and 157 (9.7%) were seropositive for FeLV and FIV, respectively. Of 4,835 cats with respiratory disease, 385 (8.0%) were seropositive for FeLV and 308 (6.4%) were seropositive for FIV. Of 1,983 cats with abscesses or bite wounds, 110 (5.5%) and 247 (12.5%) were seropositive for FeLV and FIV, respectively. Overall, 2,368 of 17,041 (13.9%) unhealthy cats were seropositive for either or both viruses, compared with 1,621 of 45,260 (3.6%) healthy cats. CONCLUSIONS AND CLINICAL RELEVANCE Seroprevalences for FeLV antigen and anti-FIV antibody were similar to those reported in previous studies over the past decade. Taken together, these results indicated a need to improve compliance with existing guidelines for management of feline retroviruses.

Correction of glutathione deficiency in the lower respiratory tract of HIV seropositive individuals by glutathione aerosol treatment.

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Holroyd, K J; Buhl, R; Borok, Z; Roum, J H; Bokser, A D; Grimes, G J; Czerski, D; Cantin, A M; Crystal, R G

1993-10-01

Concentrations of glutathione, a ubiquitous tripeptide with immune enhancing and antioxidant properties, are decreased in the blood and lung epithelial lining fluid of human immunodeficiency virus (HIV) seropositive individuals. Since the lung is the most common site of infection in those who progress to AIDS it is rational to consider whether it is possible to safely augment glutathione levels in the epithelial lining fluid of HIV seropositive individuals, thus potentially improving local host defence. Purified reduced glutathione was delivered by aerosol to HIV seropositive individuals (n = 14) and the glutathione levels in lung epithelial lining fluid were compared before and at one, two, and three hours after aerosol administration. Before treatment total glutathione concentrations in the epithelial lining fluid were approximately 60% of controls. After three days of twice daily doses each of 600 mg reduced glutathione, total glutathione levels in the epithelial lining fluid increased and remained in the normal range for at least three hours after treatment. Strikingly, even though > 95% of the glutathione in the aerosol was in its reduced form, the percentage of oxidised glutathione in epithelial lining fluid increased from 5% before treatment to about 40% three hours after treatment, probably reflecting the use of glutathione as an antioxidant in vivo. No adverse effects were observed. It is feasible and safe to use aerosolised reduced glutathione to augment the deficient glutathione levels of the lower respiratory tract of HIV seropositive individuals. It is rational to evaluate further the efficacy of this tripeptide in improving host defence in HIV seropositive individuals.

Comparison of polysomnographic data in age-, sex- and Axis I psychiatric diagnosis matched HIV-seropositive and HIV-seronegative insomnia patients.

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Low, Yinghui; Goforth, Harold W; Omonuwa, Toma; Preud'homme, Xavier; Edinger, Jack; Krystal, Andrew

2012-12-01

There is a high prevalence of insomnia in HIV-seropositive patients. Insomnia is associated with poorer disease outcomes, cognitive impairment and HIV-associated dementia. However there is limited data characterizing the type of sleep disturbances, and the cause. Previous studies report conflicting results, and observed changes in the distribution of REM and SWS were hypothesized to result from co-morbid mood disorders, although this is not established. We carried out this study to determine if there are differences in polysomnographic (PSG) sleep data in age-, sex- and Axis I diagnoses- matched HIV-seropositive and HIV-seronegative patients. Eighteen HIV-seropositive insomniacs were matched to HIV-seronegative insomniacs based on age, sex and Axis I diagnoses. Participants spent 2 consecutive nights in a sleep lab recording of PSG data. Multivariate analysis revealed an overall significant match-by-variable interaction (p=0.0126). Follow-up analysis show that compared to HIV-seronegative insomnia controls, HIV-seropositive insomniacs have significantly longer SOL, 8% decreased sleep efficiency, and 8-10% decreased time spent in REM sleep (p'saccounting for differences in age, sex and psychiatric diagnoses, HIV-seropositive patients with insomnia have significantly worse sleep than HIV-seronegative patients with insomnia. Unlike what previous authors have proposed, our results do not support the view that comorbid psychiatric disorders like depression are responsible for the observed differences in PSG findings and the greater incidence of insomnia, in HIV-seropositive patients when compared with other groups of insomnia patients. This suggests the presence of other etiologies including neuronal damage, psychosocial stressors, or comorbid medical conditions. Further studies are needed to determine the extent to which these play a role in insomnia in the HIV-seropositive population. Copyright © 2012 International Federation of Clinical Neurophysiology. Published by

Association of seropositivity for influenza and coronaviruses with history of mood disorders and suicide attempts.

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Okusaga, Olaoluwa; Yolken, Robert H; Langenberg, Patricia; Lapidus, Manana; Arling, Timothy A; Dickerson, Faith B; Scrandis, Debra A; Severance, Emily; Cabassa, Johanna A; Balis, Theodora; Postolache, Teodor T

2011-04-01

Anecdotal reports of mood disorder following infection with common respiratory viruses with neurotropic potential have been in existence since the last century. Nevertheless, systematic studies on the association between these viruses and mood disorders are lacking. Influenza A, B and coronavirus antibody titers were measured in 257 subjects with recurrent unipolar and bipolar disorder and healthy controls, by SCID. Pearson's χ² tests and logistic regression models were used to analyze associations between seropositivity for coronaviruses, influenza A and B viruses and the following: a) history of recurrent mood disorders b) having attempted suicide in the past c) uni- vs. bi-polarity and d) presence of psychotic symptoms during mood episodes. Seropositivity for influenza A (p=0.004), B (pmood disorders but not with the specific diagnosis of unipolar or bipolar depression. Seropositivity for influenza B was significantly associated with a history of suicide attempt (p=0.001) and history of psychotic symptoms (p=0.005). The design was cross-sectional. Socioeconomic factors, inflammatory markers, and axis II psychopathology were not assessed. The association of seropositivity for influenza and coronaviruses with a history of mood disorders, and influenza B with suicidal behavior require replication in larger longitudinal samples. The need for these studies is additionally supported by the high incidence of these viral infections, the high prevalence of mood disorders, and resilience of suicide epidemics. Copyright © 2010 Elsevier B.V. All rights reserved.

Nutrient Intake Values for Folate during Pregnancy and Lactation Vary Widely around the World

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Lisa A. Houghton

2013-09-01

Full Text Available Folate is a B-vitamin with particular importance during reproduction due to its role in the synthesis and maintenance of DNA. Folate is well known for its role in preventing neural tube defects (NTDs during the periconceptional period. There is also an increased need for folate throughout pregnancy to support optimal growth and development of the fetus and blood volume expansion and tissue growth of the mother. During lactation, women are at risk of folate deficiency due to increased demands to accommodate milk folate levels. Nutrient Intake Values (NIVs for folate have been calculated to take into account additional needs during pregnancy and lactation. However, these values vary widely between countries. For example, the folate requirement that is set to meet the needs of almost all healthy women during pregnancy varies from 300 µg/day in the United Kingdom to 750 µg/day in Mexico. Currently, there is no accepted standardized terminology or framework for establishing NIVs. This article reviews country-specific NIVs for folate during pregnancy and lactation and the basis for setting these reference values.

Cutaneous Microenvironment of Human Immunodeficiency Virus (HIV)-Seropositive and HIV-Seronegative Individuals, with Special Reference to Staphylococcus aureus Colonization

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Shapiro, Michael; Smith, Kathleen J.; James, William D.; Giblin, Walter J.; Margolis, David J.; Foglia, Arlene N.; McGinley, Kenneth; Leyden, James J.

2000-01-01

A cross-sectional quantitative study of cutaneous bacterial and yeast flora at seven body sites in 99 human immunodeficiency virus-seropositive and 50 seronegative military personnel was performed. Statistically significant differences in carriage rates were only observed for Staphylococcus aureus on the foreheads of seropositive individuals. Seronegative individuals demonstrated staphylococcal carriage rates 1.3 to 2 times as great as those of historical controls (defined as healthy individuals not receiving any medications) at five of six body sites. We conclude that seropositive military personnel do not exhibit statistically significant elevations in densities and carriage rates of the microorganisms examined (except Staphylococcus aureus), relative to seronegative individuals. Seropositive individuals may be predisposed to staphylococcal carriage. The elevated staphylococcal carriage rates of military personnel undergoing basic training warrants a formal evaluation of the impact of training exercises on cutaneous flora. The information gained may serve to limit the spread of infection during training exercises and battlefield conditions. PMID:10970352

Molecular genotyping of HCV infection in seropositive blood donor

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Zarin, Siti Noraziah Abu; Ibrahim, Nazlina

2013-11-01

This study is to investigate the prevalence of hepatitis C virus infection in seropositive blood donor. RNA was extracted from 32 positive samples in National Blood Centre and Melaka Hospital. The core and NS5B sequences were obtained from 23 samples. Genotype 3a is most prevalent in this study followed by genotype 1a. Evidence of mixed-genotypes (3a and 1b) infections was found in 5 subjects.

Seropositivity of Toxoplasma gondii and Toxocara spp. in Children with Cryptogenic Epilepsy, Benha, Egypt.

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Eraky, Maysa Ahmad; Abdel-Hady, Soha; Abdallah, Karim Fetouh

2016-06-01

The present study aimed to investigate the possible association of Toxoplasma gondii and Toxocara spp. infections with cryptogenic epilepsy in children. The study was carried out between June 2014 and March 2015. Total 90 children (40 with cryptogenic epilepsy, 30 with non-cryptogenic epilepsy, and 20 healthy control children) were evaluated to determine the anti-Toxocara and anti-T. gondii IgG seropositivity using ELISA kits. Epileptic cases were selected from those attending the pediatrics outpatient clinic of Benha University Hospital, Pediatrics Neurology Unit, and from Benha Specialized Hospital of children. The results showed that the level of anti-T. gondii IgG seropositivity was significantly higher among children with cryptogenic epilepsy (20%) than among children with non-cryptogenic children (0%). In healthy controls (10%), there was no association between toxocariasis seropositivity and cryptogenic epilepsy (only 5.7%; 4 out of 70 cases) among cases and 10% (2 out of 20) among controls. Among toxocariasis IgG positive cases, 3 (7.5%) were cryptogenic, and only 1 (3.3%) was non-cryptogenic. These statistically significant results support the association between T. gondii infection and cryptogenic epilepsy while deny this association with toxocariasis.

Correlates of HCV seropositivity among familial contacts of HCV positive patients

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Matera Antonio

2006-09-01

Full Text Available Abstract Background Determinants of intrafamilial HCV transmission are still being debated. The aim of this study is to investigate the correlates of HCV seropositivity among familial contacts of HCV positive patients in Italy. Methods A cross-sectional study was conducted with 175 HCV positive patients (index cases, recruited from Policlinico Gemelli in Rome as well as other hospitals in Central Italy between 1995 and 2000 (40% female, mean age 57 ± 15.2 years, and 259 familial contacts. Differences in proportions of qualitative variables were tested with non-parametric tests (χ2, Yates correction, Fisher exact test, and a p value Results Seropositivity for HCV was found in 8.9% of the contacts. From the univariate analysis, risk factors significantly associated to HCV positivity in the contacts were: intravenous drug addiction (p = 0.004 and intercourse with drug addicts (p = 0.005. The only variables associated significantly and independently to HCV seropositivity in patients' contacts were intercourse with drug addicts (OR = 19.28; 95% CI: 2.01 – 184.94, the retirement status from work (OR = 3.76; 95% CI: 1.17 – 11.98, the time of the relationship (OR = 1.06; 95% CI: 1.00 – 1.11 and tattoos (OR = 7.68; 95% CI: 1.00 – 60.20. Conclusion The present study confirms that having intercourse with a drug addict is the most significant risk factor for intrafamilial HCV transmission. The association with retirement status from work could be related to both a long-term relationship with an index case and past exposure to common risk factors.

Association of HCV Core Antigen Seropositivity with Long-Term Mortality in Patients on Regular Hemodialysis

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Akihiko Kato

2012-03-01

Full Text Available Anti-hepatitis C virus (HCV antibody seropositivity is independently associated with poor prognosis in hemodialysis (HD patients. However, anti-HCV antibody cannot distinguish between patients with active infection and those who have recovered from infection. We therefore aimed in this study to examine the association of HCV core antigen (HCVcAg seropositivity with mortality in HD patients. We first measured serum HCVcAg using an immunoradiometric assay and anti-HCV antibody in 405 patients on regular HD, and followed them for 104 months. There were 82 patients (20.2% who had been positive for anti-HCV antibodies; 57 (69.5% of these were positive for HCVcAg. During the follow-up, 29 patients were excluded, so we tested the association of HCVcAg seropositivity with all-cause, cardiovascular (CV and non-CV mortalities in 376 patients. A total of 209 patients (55.6% had expired during the observational period, 92 out of them due to CV causes. After adjusting for comorbid parameters, HCVcAg was independently associated with overall mortality (HR 1.61, 95% CI 1.05–2.47, p < 0.05. HCV infection was significantly related to liver disease-related mortality. Past HCV infection also contributed to CV mortality (HR 2.63, 95% CI 1.27–5.45, p < 0.01. In contrast, anti-HCV antibody and HCVcAg seropositivities did not associate with infectious disease-related and cancer-related (expect for hepatocellular carcinoma mortality. It follows from these findings that HCVcAg serology is associated with all-cause and CV mortality in HD patients.

Staphylococcus aureus nasal colonization in HIV-seropositive and HIV-seronegative drug users

NARCIS (Netherlands)

K.A. Holbrook; R.S. Klein; D. Hartel; D.A. Elliott; T. B. Barsky; L. H. Rothschild; F. D. Lowy

1997-01-01

textabstractNasal colonization plays an important role in the pathogenesis of Staphylococcus aureus infections. To identify characteristics associated with colonization, we studied a cross-section of a well-described cohort of HIV-seropositive and -seronegative active and former drug users

Relationships between certain metabolic diseases and selected serum biochemical parameters in seropositive dairy cows against Neospora caninum infection in different stages of lactation

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Alekish, Myassar O.; Talafha, Abdelsalam Q; Alshehabat, Musa A; Ismail, Zuhair A Bani

Neospora caninum is an important cause of abortion in dairy cattle. The general health of affected cows has not been investigated before. Therefore, the main objective of this study was to identify possible relationships between certain metabolic diseases and selected serum biochemical parameters in seropositive dairy cows against N. caninum antibodies in different stages of lactation. The study was carried out using 72 N. caninum seropositive cows and 61 seronegative dairy cows (control). Serum from all cows was tested to determine their N. caninum status (seropositive vs seronegative) using commercially available indirect enzyme-linked immunosorbent assay test kit (iELISA). In addition, serum biochemical parameters including beta-hydroxybutyrate (BHB), glucose, creatinine, blood urea nitrogen, total protein, albumin, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH) and gamma-glutamyltranspeptidase (GGT) were determined using routine laboratory methods. The stage of lactation was obtained at the time of sampling from farm records. Student independent t-test showed that there was a significant difference in the serum concentrations of BHB, AST, ALT, and LDH between seropositive and seronegative cows. There was no significant association between seropositivity and the stage of lactation. However, multivariable logistic regression analysis showed that there was a strong association between seropositivity and BHB concentrations. Results of this study indicate a possible relationship between N. caninum seropositivity and certain metabolic diseases such as ketosis and fatty liver syndrome in dairy cows.

Chlamydia trachomatis IgG3 seropositivity is a predictor of reproductive outcomes in infertile women with patent fallopian tubes

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Steiner, Anne Z.; Diamond, Michael P.; Legro, Richard S.; Schlaff, William D.; Barnhart, Kurt T.; Casson, Peter R.; Christman, Gregory M.; Alvero, Ruben; Hansen, Karl R.; Geisler, William M.; Thomas, Tracey; Santoro, Nanette; Zhang, Heping; Eisenberg, Esther

2015-01-01

Objective To determine if Chlamydia trachomatis (Ct) seropositivity as detected by the Ct elementary body (EB)-based enzyme linked immunosorbent assay (Ct EB ELISA) predicts pregnancy and pregnancy outcome among infertile women with documented tubal patency. Design Cohort study Setting Outpatient clinics participating in the reproductive medicine network Patients 1250 infertile women with documented tubal patency enrolled in one of two randomized controlled trials: PPCOSII and AMIGOS Intervention Sera were analyzed for anti-Ct IgG1 and IgG3 antibodies using a research Ct EB ELISA. OD405 readings ≥0.35 and ≥0.1 were considered positive for IgG1 and IgG3, respectively. Main Outcome Measures Primary outcomes included pregnancy, live birth, and ectopic pregnancy. Log linear regression was used to determine the relative risk after adjusting for age, race, treatment medication, smoking status, and current alcohol use. Results 243 (19%) women were seropositive for anti-Ct IgG3. They tended to be non-White and smokers. Anti-Ct IgG3 seropositive women were significantly less likely to conceive (RR 0.65, 95% CI 0.52-0.83) or to have a live birth (RR 0.59, 95% 0.43-0.80); these associations were weakened after adjusting for number of HSG-documented patent tubes (RR 0.73, 95% CI 0.56-0.97) and (0.73, 95% CI: 0.50-1.04), respectively. Anti-Ct IgG3 seropositive women who conceived had 2.7 (95% CI: 1.40-5.34) times the risk of ectopic pregnancy. Conclusions Even in the presence of tubal patency, anti-Ct IgG3 seropositivity is associated with lower likelihood of pregnancy. Anti-Ct IgG3 seropositive women have up to 3 times the risk of ectopic pregnancy. PMID:26413816

Prevention for HIV-Seropositive Persons: Successive Approximation Toward a New Identity

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Lightfoot, Marguerita; Rotheram-Borus, Mary Jane; Milburn, Norweeta G.; Swendeman, Dallas

2005-01-01

This article presents a three-module intervention based on social action theory that focuses on health promotion and social identity formation for seropositive youth. The modules are designed to reduce transmission of HIV by reducing sexual and substance abuse acts, increasing healthy acts and adherence to care, and maintaining positive behavioral…

Omega 3 Fatty Acids Supplementation and Oxidative Stress in HIV-Seropositive Patients. A Clinical Trial.

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Norma Amador-Licona

Full Text Available HIV-seropositive patients show high incidence of coronary heart disease and oxidative stress has been described as relevant key in atherosclerosis development. The aim of this study was to assess the effect of omega 3 fatty acids on different markers of oxidative stress in HIV-seropositive patients. We performed a randomized parallel controlled clinical trial in The Instituto Mexicano del Seguro Social, a public health hospital. 70 HIV-seropositive patients aged 20 to 55 on clinical score A1, A2, B1 or B2 receiving highly active antiretroviral therapy (HAART were studied. They were randomly assigned to receive omega 3 fatty acids 2.4 g (Zonelabs, Marblehead MA or placebo for 6 months. At baseline and at the end of the study, anthropometric measurements, lipid profile, glucose and stress oxidative levels [nitric oxide catabolites, lipoperoxides (malondialdehyde plus 4-hydroxialkenals, and glutathione] were evaluated. Principal HAART therapy was EFV/TDF/FTC (55% and AZT/3TC/EFV (15% without difference between groups. Treatment with omega 3 fatty acids as compared with placebo decreased triglycerides (-0.32 vs. 0.54 mmol/L; p = 0.04, but oxidative stress markers were not different between groups.

Predictors of sharing injection equipment by HIV-seropositive injection drug users.

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Latkin, Carl A; Buchanan, Amy S; Metsch, Lisa R; Knight, Kelly; Latka, Mary H; Mizuno, Yuko; Knowlton, Amy R

2008-12-01

Among HIV-positive injection drug users (IDUs), we examined baseline predictors of lending needles and syringes and sharing cookers, cotton, and rinse water in the prior 3 months at follow-up. Participants were enrolled in Intervention for Seropositive Injectors-Research and Evaluation, a secondary prevention intervention for sexually active HIV-positive IDUs in 4 US cities during 2001-2005. The analyses involved 357 participants who reported injecting drugs in the prior 6 months at either the 6- or 12-month follow-up visit. About half (49%) reported at least 1 sharing episode. In adjusted analyses, peer norms supporting safer injection practices and having primary HIV medical care visits in the prior 6 months were associated with reporting no sharing of injection equipment. Higher levels of psychological distress were associated with a greater likelihood of reporting drug paraphernalia sharing. These findings suggest that intervention approaches for reducing HIV-seropositive IDUs' transmission of blood-borne infections should include peer-focused interventions to alter norms of drug paraphernalia sharing and promoting primary HIV care and mental health services.

Chlamydia trachomatis immunoglobulin G3 seropositivity is a predictor of reproductive outcomes in infertile women with patent fallopian tubes.

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Steiner, Anne Z; Diamond, Michael P; Legro, Richard S; Schlaff, William D; Barnhart, Kurt T; Casson, Peter R; Christman, Gregory M; Alvero, Ruben; Hansen, Karl R; Geisler, William M; Thomas, Tracey; Santoro, Nanette; Zhang, Heping; Eisenberg, Esther

2015-12-01

To determine if Chlamydia trachomatis (C. trachomatis) seropositivity, as detected by the C. trachomatis elementary body (EB)-based enzyme-linked immunosorbent assay [EB ELISA] predicts pregnancy and pregnancy outcome among infertile women with documented tubal patency. Cohort study. Outpatient clinics. In all, 1,250 infertile women with documented tubal patency enrolled in 1 of 2 randomized controlled trials: Pregnancy in Polycystic Ovary Syndrome II; and the Assessment of Multiple Intrauterine Gestations From Ovarian Stimulation. Sera were analyzed for anti-C. trachomatis immunoglobulin G (IgG)1 and IgG3 antibodies, using a research C. trachomatis EB ELISA. The optical density (OD)405 readings of ≥ 0.35 and ≥ 0.1 were considered positive for IgG1 and IgG3, respectively. Primary outcomes included pregnancy, live birth, and ectopic pregnancy. Log-linear regression was used to determine the relative risk after adjusting for age, race, treatment medication, smoking status, and current alcohol use. A total of 243 (19%) women were seropositive for anti-C. trachomatis IgG3. They tended to be nonwhite and smokers. Anti-C. trachomatis IgG3 seropositive women were significantly less likely to conceive (risk ratio [RR] 0.65, 95% confidence interval [CI] 0.52-0.83) or to have a live birth (RR 0.59, 95% CI 0.43-0.80); these associations were weakened after adjusting for number of hysterosalpingography-documented patent tubes (RR 0.73, 95% CI 0.56-0.97) and (RR 0.73, 95% CI 0.50-1.04), respectively. Anti-C. trachomatis IgG3 seropositive women who conceived had a ×2.7 risk (95% CI 1.40-5.34) of ectopic pregnancy. Even in the presence of tubal patency, anti-C. trachomatis IgG3 seropositivity is associated with a lower likelihood of pregnancy. Anti-C. trachomatis IgG3 seropositive women have as high as 3 times the risk of ectopic pregnancy. PPCOSII: NCT00719186 and AMIGOS: NCT01044862. Copyright © 2015 American Society for Reproductive Medicine. All rights reserved.

CMV seropositivity determines epoetin dose and hemoglobin levels in patients with CKD

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M.G.H. Betjes (Michiel); W. Weimar (Willem); N.H.R. Litjens (Nicolle)

2009-01-01

textabstractCytomegalovirus (CMV)-seropositive patients with ESRD may have more CD4+T cells lacking the co-stimulatory molecule CD28 (CD4+CD28null) than CMV-seronegative patients. Increased numbers of CD28null T cells associates with epoetin nonresponsiveness in patients with ESRD, but whether

Risk factors of Coxiella burnetii (Q fever) seropositivity in veterinary medicine students.

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de Rooij, Myrna M T; Schimmer, Barbara; Versteeg, Bart; Schneeberger, Peter; Berends, Boyd R; Heederik, Dick; van der Hoek, Wim; Wouters, Inge M

2012-01-01

Q fever is an occupational risk for veterinarians, however little is known about the risk for veterinary medicine students. This study aimed to assess the seroprevalence of Coxiella burnetii among veterinary medicine students and to identify associated risk factors. A cross-sectional study with questionnaire and blood sample collection was performed among all veterinary medicine students studying in The Netherlands in 2006. Serum samples (n = 674), representative of all study years and study directions, were analyzed for C. burnetii IgG and IgM phase I and II antibodies with an immunofluorescence assay (IFA). Seropositivity was defined as IgG phase I and/or II titer of 1:32 and above. Of the veterinary medicine students 126 (18.7%) had IgG antibodies against C. burnetii. Seropositivity associated risk factors identified were the study direction 'farm animals' (Odds Ratio (OR) 3.27 [95% CI 2.14-5.02]), advanced year of study (OR year 6: 2.31 [1.22-4.39] OR year 3-5 1.83 [1.07-3.10]) having had a zoonosis during the study (OR 1.74 [1.07-2.82]) and ever lived on a ruminant farm (OR 2.73 [1.59-4.67]). Stratified analysis revealed study direction 'farm animals' to be a study-related risk factor apart from ever living on a farm. In addition we identified a clear dose-response relation for the number of years lived on a farm with C. burnetii seropositivity. C. burnetii seroprevalence is considerable among veterinary medicine students and study related risk factors were identified. This indicates Q fever as an occupational risk for veterinary medicine students.

Toxocara seropositivity, atopy and wheezing in children living in poor neighbourhoods in urban Latin American.

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Lívia Ribeiro Mendonça

Full Text Available Toxocara canis and T. cati are parasites of dogs and cats, respectively, that infect humans and cause human toxocariasis. Infection may cause asthma-like symptoms but is often asymptomatic and is associated with a marked eosinophilia. Previous epidemiological studies indicate that T. canis infection may be associated with the development of atopy and asthma.To investigate possible associations between Toxocara spp. seropositivity and atopy and childhood wheezing in a population of children living in non-affluent areas of a large Latin American city.The study was conducted in the city of Salvador, Brazil. Data on wheezing symptoms were collected by questionnaire, and atopy was measured by the presence of aeroallergen-specific IgE (sIgE. Skin prick test (SPT, total IgE and peripheral eosinophilia were measured. Toxocara seropositivity was determined by the presence of anti-Toxocara IgG antibodies, and intestinal helminth infections were determined by stool microscopy.Children aged 4 to 11 years were studied, of whom 47% were seropositive for anti-Toxocara IgG; eosinophilia >4% occurred in 74.2% and >10% in 25.4%; 59.6% had elevated levels of total IgE; 36.8% had sIgE≥0.70 kU/L and 30.4% had SPT for at least one aeroallergen; 22.4% had current wheezing symptoms. Anti-Toxocara IgG was positively associated with elevated eosinophils counts, total IgE and the presence of specific IgE to aeroallergens but was inversely associated with skin prick test reactivity.The prevalence of Toxocara seropositivity was high in the studied population of children living in conditions of poverty in urban Brazil. Toxocara infection, although associated with total IgE, sIgE and eosinophilia, may prevent the development of skin hypersensitivity to aeroallergens, possibly through increased polyclonal IgE and the induction of a modified Th2 immune reaction.

Cutaneous Microenvironment of Human Immunodeficiency Virus (HIV)-Seropositive and HIV-Seronegative Individuals, with Special Reference to Staphylococcus aureus Colonization

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Shapiro, Michael; Smith, Kathleen J.; James, William D.; Giblin, Walter J.; Margolis, David J.; Foglia, Arlene N.; McGinley, Kenneth; Leyden, James J.

2000-01-01

A cross-sectional quantitative study of cutaneous bacterial and yeast flora at seven body sites in 99 human immunodeficiency virus-seropositive and 50 seronegative military personnel was performed. Statistically significant differences in carriage rates were only observed for Staphylococcus aureus on the foreheads of seropositive individuals. Seronegative individuals demonstrated staphylococcal carriage rates 1.3 to 2 times as great as those of historical controls (defined as healthy individu...

Estimates of Continental Ancestry Vary Widely among Individuals with the Same mtDNA Haplogroup

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Emery, Leslie S.; Magnaye, Kevin M.; Bigham, Abigail W.; Akey, Joshua M.; Bamshad, Michael J.

2015-01-01

The association between a geographical region and an mtDNA haplogroup(s) has provided the basis for using mtDNA haplogroups to infer an individual’s place of origin and genetic ancestry. Although it is well known that ancestry inferences using mtDNA haplogroups and those using genome-wide markers are frequently discrepant, little empirical information exists on the magnitude and scope of such discrepancies between multiple mtDNA haplogroups and worldwide populations. We compared genetic-ancestry inferences made by mtDNA-haplogroup membership to those made by autosomal SNPs in ∼940 samples of the Human Genome Diversity Panel and recently admixed populations from the 1000 Genomes Project. Continental-ancestry proportions often varied widely among individuals sharing the same mtDNA haplogroup. For only half of mtDNA haplogroups did the highest average continental-ancestry proportion match the highest continental-ancestry proportion of a majority of individuals with that haplogroup. Prediction of an individual’s mtDNA haplogroup from his or her continental-ancestry proportions was often incorrect. Collectively, these results indicate that for most individuals in the worldwide populations sampled, mtDNA-haplogroup membership provides limited information about either continental ancestry or continental region of origin. PMID:25620206

Treatment of cervical cancer in HIV-seropositive women from developing countries: a protocol for a systematic review.

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Mapanga, Witness; Chipato, Tsungai; Feresu, Shingairai A

2018-01-25

Cervical cancer has become the most common cancer affecting women in Africa. Significantly, 85% of these annual deaths occur in the developing world, with the majority being middle-aged women. Research has shown that in sub-Saharan Africa, cervical cancer trends are on the rise in the past two decades because of HIV and this has resulted in an increase in cervical cancer cases among young women. However, little or no information exists that has shown that any of the available treatment methods are more effective than others when it comes to treating cervical cancer in HIV-seropositive women. The aim of this protocol is to offer a plan on how to systematically review cervical cancer treatment methods available for HIV-seropositive women in developing countries. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement was used to develop the protocol for the systematic review which will be reported in accordance with the PRISMA guidelines. A number of databases, Embase, MEDLINE, PubMed, CINAHL and Cochrane Library, will be searched for relevant studies, and citation and reference list tracking will be used to search for additional studies. Prospective and retrospective cohort studies, case-control, randomised controlled trials and cross-sectional studies that were carried out in and for the developing world will be eligible for inclusion. Peer-reviewed studies and grey literature examining cervical cancer treatment modalities in HIV-seropositive women will be included. Descriptive statistics and tables will be used to summarise results, and meta-analysis will be used where appropriate. The review findings will provide the current picture of the existing treatment methods being used to treat cervical cancer in HIV-seropositive women in developing countries. The findings might be used for the establishment of evidence-based guidelines for treatment of cervical cancer in seropositive women as well as prompt policy-makers and

Seroprevalence of Measles Antibodies and Predictors for Seropositivity among Chinese Children.

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Wang, Xiaoqin; Ma, Mei; Hui, Zhaozhao; Terry, Paul D; Zhang, Yue; Su, Rui; Wang, Mingxu; Gu, Wei; Li, Ling

2017-06-06

Background : Supplementary measles immunization has been implemented since 2010 throughout China, yet few studies have reported its effect in the northwest regions. Methods: A cross-sectional study was conducted among children aged 2 to 4 years old ( n = 755) from February to September 2014 in 25 towns of Qian County, Shaanxi Province. Blood samples were analyzed for measles antibodies using enzyme-linked immunosorbent immunoglobulin G (IgG) assays. Socio-demographic factors were assessed by questionnaire. Data on vaccine dose were collected from town medical records. Univariate and logistic regression analyses were used to determine factors associated with measles antibody seropositivity. Results : Measles antibody seroprevalence was 91.13% (95% CI: 89.52-92.83) in our sample. Compared with children whose mother's highest education was primary school, seroprevalence was higher in children whose maternal education was middle school (adjusted OR: 1.4, 95% CI: 0.7-2.8), high school (adjusted OR: 2.4, 95% CI: 1.3-7.7), and college/university (adjusted OR: 2.9, 95% CI: 1.2-9.3). Vaccine dose was positively associated with seropositivity. Conclusions : Measles seroprevalence is high in China and is associated with the mother's education and vaccine dose.

Seropositivity to non-vaccine incorporated genotypes induced by the bivalent and quadrivalent HPV vaccines: A systematic review and meta-analysis.

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Bissett, Sara L; Godi, Anna; Jit, Mark; Beddows, Simon

2017-07-13

Human papillomavirus vaccines have demonstrated remarkable efficacy against persistent infection and disease associated with vaccine-incorporated genotypes and a degree of efficacy against some genetically related, non-vaccine-incorporated genotypes. The vaccines differ in the extent of cross-protection against these non-vaccine genotypes. Data supporting the role for neutralizing antibodies as a correlate or surrogate of cross-protection are lacking, as is a robust assessment of the seroconversion rates against these non-vaccine genotypes. We performed a systematic review and meta-analysis of available data on vaccine-induced neutralizing antibody seropositivity to non-vaccine incorporated HPV genotypes. Of 304 articles screened, 9 were included in the analysis representing ca. 700 individuals. The pooled estimate for seropositivity against HPV31 for the bivalent vaccine (86%; 95%CI 78-91%) was higher than that for the quadrivalent vaccine (61%; 39-79%; p=0.011). The pooled estimate for seropositivity against HPV45 for the bivalent vaccine (50%; 37-64%) was also higher than that for the quadrivalent vaccine (16%; 6-36%; p=0.007). Seropositivity against HPV33, HPV52 and HPV58 were similar between the vaccines. Mean seropositivity rates across non-vaccine genotypes were positively associated with the corresponding vaccine efficacy data reported from vaccine trials. These data improve our understanding of vaccine-induced functional antibody specificity against non-vaccine incorporated genotypes and may help to parameterize vaccine-impact models and improve patient management in a post-vaccine setting. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Risk Factors of Coxiella burnetii (Q Fever) Seropositivity in Veterinary Medicine Students

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de Rooij, Myrna M. T.; Schimmer, Barbara; Versteeg, Bart; Schneeberger, Peter; Berends, Boyd R.; Heederik, Dick; van der Hoek, Wim; Wouters, Inge M.

2012-01-01

Background Q fever is an occupational risk for veterinarians, however little is known about the risk for veterinary medicine students. This study aimed to assess the seroprevalence of Coxiella burnetii among veterinary medicine students and to identify associated risk factors. Methods A cross-sectional study with questionnaire and blood sample collection was performed among all veterinary medicine students studying in the Netherlands in 2006. Serum samples (n = 674), representative of all study years and study directions, were analyzed for C. burnetii IgG and IgM phase I and II antibodies with an immunofluorescence assay (IFA). Seropositivity was defined as IgG phase I and/or II titer of 1∶32 and above. Results Of the veterinary medicine students 126 (18.7%) had IgG antibodies against C. burnetii. Seropositivity associated risk factors identified were the study direction ‘farm animals’ (Odds Ratio (OR) 3.27 [95% CI 2.14–5.02]), advanced year of study (OR year 6: 2.31 [1.22–4.39] OR year 3–5 1.83 [1.07–3.10]) having had a zoonosis during the study (OR 1.74 [1.07–2.82]) and ever lived on a ruminant farm (OR 2.73 [1.59–4.67]). Stratified analysis revealed study direction ‘farm animals’ to be a study-related risk factor apart from ever living on a farm. In addition we identified a clear dose-response relation for the number of years lived on a farm with C. burnetii seropositivity. Conclusions C. burnetii seroprevalence is considerable among veterinary medicine students and study related risk factors were identified. This indicates Q fever as an occupational risk for veterinary medicine students. PMID:22363803

Reciprocal moderation by Toxoplasma gondii seropositivity and blood phenylalanine - tyrosine ratio of their associations with trait aggression.

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Mathai, Ashwin Jacob; Lowry, Christopher A; Cook, Thomas B; Brenner, Lisa A; Brundin, Lena; Groer, Maureen W; Peng, Xiaoqing; Giegling, Ina; Hartmann, Annette M; Konte, Bettina; Friedl, Marion; Fuchs, Dietmar; Rujescu, Dan; Postolache, Teodor T

2016-12-01

We previously reported that trait aggression, proposed as an endophenotype for suicidal behavior, is positively associated with Toxoplasma gondii ( T. gondii ) seropositivity in females, but not in males. Additionally, older males seropositive for T. gondii had lower scores on measures of trait aggression, including self-aggression. Trait aggression may be influenced by dopaminergic signaling, which is known to be moderated by gender and age, and potentially enhanced in T. gondii positives through the intrinsic production of dopamine by the microorganism. Therefore, we investigated associations between trait aggression and interactions between T. gondii enzyme-linked immunoabsorbant assay (ELISA) IgG titer-determined seropositivity and high-performance liquid chromatography- (HPLC-) measured blood levels of dopamine precursors phenylalanine (Phe), tyrosine (Tyr), and their ratio in a sample of 1000 psychiatrically healthy participants. Aggressive traits were assessed using the questionnaire for measuring factors of aggression (FAF), the German version of the Buss-Durkee hostility questionnaire. We found that 1) the decrease in trait aggression scores in T. gondii -positive older males was only present in individuals with a low Phe:Tyr ratio, and 2) that there was a positive correlation between Phe:Tyr ratio and total aggression and selected subscales of aggression in T. gondii -positive males, but not in T. gondii -negative males. These findings point toward a gender-specific reciprocal moderation by Phe:Tyr ratio and T. gondii seropositivity of their associations with aggression scores, and lead to experimental interventions geared to manipulating levels of dopamine precursors in selected T. gondii positive individuals with increased propensity for aggression.

Neuromyelitis optica spectrum disorders: comparison of clinical and magnetic resonance imaging characteristics of AQP4-IgG versus MOG-IgG seropositive cases in the Netherlands.

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van Pelt, E D; Wong, Y Y M; Ketelslegers, I A; Hamann, D; Hintzen, R Q

2016-03-01

Neuromyelitis optica spectrum disorders (NMOSDs) are a group of rare inflammatory demyelinating disorders of the central nervous system. The identification of specific antibodies directed to aquaporin 4 (AQP4-IgG) led to the distinction from multiple sclerosis. However, up to 25% of the clinically diagnosed NMO patients are seronegative for AQP4-IgG. A subgroup of these patients might be identified by antibodies directed to myelin oligodendrocyte glycoprotein (MOG-IgG). Our objective was to investigate whether the clinical characteristics of these patients differ. Using a cell-based assay, samples of 61 AQP4-IgG seronegative patients and 41 AQP4-IgG seropositive patients with clinically NMOSD were analysed for the presence of MOG-IgG. Clinical characteristics of the AQP4-IgG, MOG-IgG seropositive and double seronegative NMOSD patients were compared. Twenty of the 61 AQP4-IgG seronegative patients tested MOG-IgG seropositive (33%). MOG-IgG seropositive patients were more frequently males in contrast to AQP4-IgG seropositive patients (55% vs. 15%, P < 0.01) and Caucasians (90% vs. 63%, P = 0.03). They more frequently presented with coincident optic neuritis and transverse myelitis (40% vs. 12%, P = 0.02) and had a monophasic disease course (70% vs. 29%, P < 0.01). AQP4-IgG seropositive patients were 2.4 times more likely to suffer from relapses compared with MOG-IgG seropositive patients (relative risk 2.4, 95% confidence interval 1.2-4.7). AQP4-IgG seropositive patients had higher Expanded Disability Status Scale levels at last follow-up (P < 0.01). Antibodies directed to MOG identify a subgroup of AQP4-IgG seronegative NMO patients with generally a favourable monophasic disease course. © 2015 EAN.

Seroprevalence and factors associated with seropositivity to equine arteritis virus in Spanish Purebred horses in Spain.

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Cruz, F; Fores, P; Mughini-Gras, L; Ireland, J; Moreno, M A; Newton, R

2016-09-01

Equine viral arteritis (EVA), a disease caused by infection with the equine arteritis virus (EAV), is present in many European countries. In Spain, the last confirmed outbreak was reported in 1992 and there is a paucity of seroprevalence studies. The disease has a major impact on the equine breeding industry, which is mainly represented by Spanish Purebred (SP) horses in Spain. To estimate the seroprevalence of EAV in the breeding SP horse population in central Spain and identify potential horse and studfarm level factors associated with seropositivity to EAV. Cross-sectional study. Individual serum samples from 555 SP horses, collected between September 2011 and November 2013 at 35 studfarms, were tested using a commercially available EAV antibody ELISA and seroneutralisation as the World Organisation for Animal Health reference confirmation test for samples with positive and equivocal results. Data on factors putatively associated with seropositivity to EAV were collected via a questionnaire and examined using random effects logistic regression for analysis of clustered data. Equine arteritis virus seroprevalence in the SP breeding population in central Spain standardised for the sex distribution of the reference horse population, was estimated to be 16.8% (95% confidence interval 5.2-28.5%). Increasing numbers of breeding mares on the studfarm and increasing percentage of mares with reproductive problems during the last 12 months were identified as being positively associated with EAV seropositivity. Mares vaccinated against Equine herpesvirus-1 (EHV-1) and/or -4 (EHV-4) were also positively associated with EAV seropositivity. These findings are of importance to ensure appropriate biosecurity measures for studfarms are carried out and may help facilitate the development of an EVA surveillance programme in the SP breeding horse population. © 2015 EVJ Ltd.

The severity of the articular deformities of the hands depending on the seropositivity in rheumatoid arthritis

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Oprea Doiniţa

2017-11-01

Full Text Available Background. Rheumatoid arthritis (RA, met in the literature also as chronic evolving polyarthritis, is a chronic inflammatory disease, which typically involves the small and medium joints, with a symmetric distribution. Clinical studies shown that a proportion of patients with RA, without measurable rheumatoid factors are a distinct entity from those patients with seropositive RA. Around one third of patients with RA are seronegative for those two serological markers, the rheumatoid factors (RF and anti-citrullinated peptide antibodies (Anti-CCP. Hands are the most frequently affected in both seropositive and seronegative RA and the first joints involved in the inflammatory process are the metacarpo-phalangeal joints, IFP joints and the radiocarpian joint. The big joints become later symptomatic, after the small joints are affected. Materials and methods: 66 patients files and the personal records of the patients consecutively admitted in the Rheumatology Department of the Clinical Emergency County Hospital Constanta. Patients from county Constanta were included in the study, with diagnosis of rheumatoid arthritis (diagnosis confirmed at least 2 years ago, including both forms (seropositive and seronegative of the disease. The complete clinical exam was done for the patients included in the study, following the identification of the active joint disease. The mechanical status of the joint was observed by a single evaluator for each of those 66 patients with RA, with special focus on the presence of the deformities / ankyloses of the hands joints. Therefore, there were evaluated: the mobility (the number of the joints with limited movements, deformities, ankyloses (the number of the joints without mobility. The joint mobility was assessed by counting the hand joints with limited movements and the worsening of the prehension function. The presence of the following hand deformities was followed: fingers in “swan neck”, “fusiform fingers�

Soluble glycoprotein VI, a specific marker of platelet activation is increased in the plasma of subjects with seropositive rheumatoid arthritis.

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John R Stack

Full Text Available Anti-citrullinated protein antibodies (ACPA have been shown to cause platelet activation in vitro, through the low-affinity immunoglobulin G (IgG receptor (FcγRIIa on platelets. Platelet activation via engagement of FcγRIIa results in proteolytic cleavage and shedding of platelet specific glycoprotein VI (GPVI which can be detected in the plasma as soluble GPVI (sGPVI. We hypothesized that plasma levels of sGPVI would be increased among patients with seropositive RA as a consequence of antibody-induced platelet activation and GPVI shedding.Samples from 84 patients with RA (65 seropositive and 19 seronegative and 67 healthy controls were collected prospectively and analysed for sGPVI using a standardised ELISA.Patients with seropositive RA had significantly higher levels of sGPVI compared to seronegative RA and controls. Median (IQR sGPVI levels were 4.2 ng/ml (3.2, 8.0 in seropositve RA, 2.2 ng/ml (1.5, 3.5 in seronegative RA and 2.2 ng/ml (1.6, 3.4 in controls (p<0.0001. sGPVI levels correlated with ACPA titres (r = 0.32, p = 0.0026 and with RF titres (r = 0.48, p<0.0001.Plasma sGPVI, a specific marker of platelet activation is increased among patients with seropositive RA.

A Comparison of Chronic Periodontitis in HIV-Seropositive Subjects and the General Population in the Ga-Rankuwa Area, South Africa

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Razia Khammissa

2012-01-01

Full Text Available The effect of HIV infection on the prevalence and the rate of progression of chronic periodontitis is not clear. The aim of this study was to compare parameters associated with the severity of chronic periodontitis in terms of periodontal probing depths, gingival recession, plaque indexes, and bleeding indexes of HIV-seropositive subjects and healthy age-matched control subjects, and of HIV-seropositive subjects on highly active antiretroviral therapy and those not receiving such treatment. Two cohorts of subjects with chronic periodontitis were recruited for this study over a period of six months. There were 30 HIV-seropositive subjects, and 30 control subjects. Periodontal probing depths, gingival marginal recession, plaque indexes, and bleeding indexes were compared by HIV serostatus, the use of highly active antiretroviral therapy, and CD4+ T-cell counts. All participants were black persons between the age of 18 and 45 and were of a similar socioeconomic status and age. The results of this study indicate that chronic periodontitis in HIV-seropositive subjects is similar in terms of mean periodontal probing depth, gingival marginal recession, plaque index, and bleeding index to that in healthy age-matched control subjects, and a low CD4+ T-cell count does not appear to be a risk factor for increased severity of chronic periodontitis.

Seropositivity of Toxoplasma gondii in domestic donkeys (Equus asinus) and isolation of T. gondii from farm cats.

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Dubey, J P; Ness, S L; Kwok, O C H; Choudhary, S; Mittel, L D; Divers, T J

2014-01-17

Donkeys (Equus asinus) are used as both companion and working animals throughout the world and in some countries, their meat and milk are used for human consumption. Here we report the first serological survey of Toxoplasma gondii in donkeys in the United States. Serum samples from 373 donkeys from eight farms in five states were tested for T. gondii antibodies by the modified agglutination test (MAT). Twenty-four of 373 (6.4%) of donkeys were seropositive, with MAT titers ranging from 25 to ≥ 200. All seropositive donkeys were Miniature breed. Seropositivity prevalence was 7.0% in female donkeys (20/282) and 4.1% in male donkeys (4/91). No donkeys less than 24 months of age (129) were seropositive, suggesting postnatal transmission of infection. Domestic cats were present on six of the eight farms. Three cats from one farm had MAT titers of 200. Viable T. gondii was isolated from the hearts of two cats, but not from brain tissues. Genotyping of isolate DNA extracted from culture-derived tachyzoites using 10 PCR-restriction fragment length polymorphism (RFLP) markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, PK1, L358 and Apico loci) revealed that both isolates were clonal Type II (ToxoDB PCR-RFLP genotype #1). This is the first serological survey for T. gondii in donkeys in the United States, and suggests that donkey milk and meat should be considered as a potential source for human infection. The role of barn cats in the transmission of T. gondii to donkeys on farms warrents further investigation. Copyright © 2013 Elsevier B.V. All rights reserved.

Seroprevalence of Measles Antibodies and Predictors for Seropositivity among Chinese Children

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Xiaoqin Wang

2017-06-01

Full Text Available Background: Supplementary measles immunization has been implemented since 2010 throughout China, yet few studies have reported its effect in the northwest regions. Methods: A cross-sectional study was conducted among children aged 2 to 4 years old (n = 755 from February to September 2014 in 25 towns of Qian County, Shaanxi Province. Blood samples were analyzed for measles antibodies using enzyme-linked immunosorbent immunoglobulin G (IgG assays. Socio-demographic factors were assessed by questionnaire. Data on vaccine dose were collected from town medical records. Univariate and logistic regression analyses were used to determine factors associated with measles antibody seropositivity. Results: Measles antibody seroprevalence was 91.13% (95% CI: 89.52–92.83 in our sample. Compared with children whose mother’s highest education was primary school, seroprevalence was higher in children whose maternal education was middle school (adjusted OR: 1.4, 95% CI: 0.7–2.8, high school (adjusted OR: 2.4, 95% CI: 1.3–7.7, and college/university (adjusted OR: 2.9, 95% CI: 1.2–9.3. Vaccine dose was positively associated with seropositivity. Conclusions: Measles seroprevalence is high in China and is associated with the mother’s education and vaccine dose.

Chronic genital ulcer disease with subsequent development of methicillin-resistant Staphylococcus aureus (MRSA urethritis and bacteraemia in an HIV-seropositive person – a case observation

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Christine Katusiime

2012-03-01

Full Text Available HIV-seropositive persons are at increased risk of methicillin-resistant Staphylococcus aureus (MRSA. Genital ulcerative disease and sexually transmitted infection with subsequent MRSA infection in HIV-seropositive persons have been documented only once. We report a case of a 44-year-old man who presented to the Infectious Diseases Institute, Kampala, Uganda, with chronic genital ulcer disease and who subsequently developed MRSA urethritis and bacteraemia. This case also demonstrates that persistent genital ulcer disease in HIV-seropositive persons may be as a result of concurrent MRSA infection.

Associations of Neospora caninum seropositivity with gestation number and pregnancy outcome in Danish dairy herds

DEFF Research Database (Denmark)

Jensen, Anette Møllegaard; Bjorkman, C.; Kjeldsen, A.M.

1999-01-01

The prevalence and distribution of seropositivity towards the protozoan parasite Neospora caninum were studied in single blood samples from 1561 cows from 31 Danish dairy herds. Blood samples were analysed by an indirect enzyme-linked immunoassay and an indirect fluorescent-antibody test, Seropre......The prevalence and distribution of seropositivity towards the protozoan parasite Neospora caninum were studied in single blood samples from 1561 cows from 31 Danish dairy herds. Blood samples were analysed by an indirect enzyme-linked immunoassay and an indirect fluorescent-antibody test......, Seroprevalence in 15 herds with previous abortions assigned to neosporosis ranged from I% to 58%, with a mean frequency of 22%. In eight out of 16 herds without a history of N. caninum related abortions, no seroreactors were found. In the remaining eight herds, the seroprevalence ranged from 6% to 59...

Disease flare of ankylosing spondylitis presenting as reactive arthritis with seropositivity: a case report

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Manoj EM

2012-02-01

Full Text Available Abstract Introduction Concurrent rheumatoid factor seropositivity is occasionally detected in ankylosing spondylitis and often causes confusion in clinical routine. Overlap between various seronegative arthritides is a known but uncommon association. Differentiation of spondyloarthropathy from rheumatoid arthritis is important, since the natural history, complications, treatments and prognosis of the two diseases differ significantly. Case presentation Here, we report the case of a 47-year-old Sri Lankan man who had a long history of intermittent joint pains worsening following a recent episode of self-resolving non-bloody diarrhea. Subsequently, he developed a skin rash suggestive of keratoderma blenorrhagica and circinate balanitis. He had classical radiological evidence of ankylosing spondylosis (previously undiagnosed associated with human leukocyte antigen B27 antigen, but was positive for rheumatoid factor. Conclusions A disease flare of ankylosing spondylitis prompted by a minor diarrheal illness showing well documented features of reactive arthritis is remarkable. The prognostic implications of seropositivity in spondyloarthritis are discussed.

Factors associated with seropositivity for anti-Toxoplasma gondiiantibodies in pregnant women of Londrina, Paraná, Brazil

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FMR Lopes

2009-03-01

Full Text Available The aim of this study was to evaluate associations between seropositivity for IgG and IgM anti-Toxoplasma gondii antibodies and socio-economic and environmental variables in pregnant women of Londrina, state of Paraná, Brazil. We interviewed 492 pregnant women, each of whom answered an epidemiological questionnaire, and collected blood samples for measurement of IgG and IgM anti-T. gondii antibodies by chemiluminescence. A confirmatory diagnosis of acute infection was made by an IgG avidity test. Titres of specific IgG anti-T. gondii were obtained by IFAT. Seropositivity for IgG anti-T. gondii antibodies was observed in 242 women (49.2% and, of these, six pregnant women (1.2% showed seropositivity for IgM. Age group, level of education, per capita income, presence of a cat in the house and a habit of eating green vegetables were all factors associated with a greater chance of infection with T. gondii. This study showed that 250 (50.8% pregnant women were susceptible to T. gondii and considered to be at high risk for toxoplasmosis during pregnancy. Based on the results obtained, is critical to establish a program of health surveillance for toxoplasmosis, in order to contribute to diagnosis and early treatment during the prenatal period. It is also necessary to introduce measures to prevent the Toxoplasma infection in seronegative pregnant women.

Predictive markers of survival in HIV-seropositive and HIV-seronegative Tanzanian patients with extrapulmonary tuberculosis

NARCIS (Netherlands)

Richter, C.; Koelemay, M. J.; Swai, A. B.; Perenboom, R.; Mwakyusa, D. H.; Oosting, J.

1995-01-01

Prediction of survival in Tanzanian patients with extrapulmonary tuberculosis (TB). To evaluate the prognostic value of clinical and laboratory parameters on survival in human immunodeficiency virus (HIV) seropositive and HIV seronegative patients with extrapulmonary TB. Over an 8-month period 192

Individual and environmental risk factors for dengue and chikungunya seropositivity in North-Eastern Tanzania

DEFF Research Database (Denmark)

Kajeguka, Debora C.; Msonga, Maulid; Schiøler, Karin L.

2017-01-01

was associated with G6PD status (p = 0.03) while there was no apparent association between genetic factors (G6PD, HbB or alpha-thalassemia) and chikungunya seropositivity. Conclusion: Public health education on environmental management practices is needed to eliminate the identified risks such as simple removal...

Seropositivity of hepatitis C in prison inmates of Pakistan--a cross sectional study in prisons of Sindh.

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Gorar, Zulfikar Ali; Zulfikar, Imrana

2010-06-01

To assess the proportion of seropositivity of Hepatitis C amongst the prison inmates in the jails of Sindh. A cross sectional HCV seroprevalence survey was done at 14 out of 19 prisons in the Sindh province from November 2008 to January 2009. A team of Pathologist, phlebotomist and laboratory technician took the blood sample of the inmates inside the correctional facility; the blood was centrifuged at the spot and brought back to the pathology laboratory on same day in cold chain i.e. a temperature-controlled supply chain. Serum was analyzed on 3rd generation ELISA for HCV antibodies. Standard ethical considerations were properly followed. Atotal of 9508 prison inmates were approached. Refusal rate was 20%. Remaining, 7539 prisoners were screened at 14 out of 19 jails in Sindh. HCV antibody positive were 965 making the proportion of seropositivity 12.8% (95% C.I. 8.92% - 12.92%). Higher seropositivity in the jails of northern Sindh jails was identified. Hepatitis C prevalence in the prison population of Sindh is higher than the national prevalence of 4.9% amongst general population. However it is lower than that reported from correctional facilities of developed countries. Hepatitis prevention and control activities in the correctional facilities of Pakistan need to be institutionalized (JPMA 60:476; 2010).

Mycobacterium avium and purified protein derivative-specific cytotoxicity mediated by CD4+ lymphocytes from healthy HIV-seropositive and-seronegative individuals

DEFF Research Database (Denmark)

Ravn, P; Pedersen, B K

1996-01-01

mycobacteria. Our objective was to investigate the M.tuberculosis-and M. avium-specific cytotoxic capacity of T cells from healthy, bacille Calmette-Guérin-vaccinated, HIV-seropositive individuals. Blood mononuclear cells were obtained from 10 healthy HIV-seropositive and 10 healthy seronegative persons...... with no history of previous or active mycobacterial infection. Antigen-specific killing of macrophages presenting mycobacterial antigens (purified protein derivative or M. avium culture filtrate) was conducted. The phenotype of the killer cells was determined by a fluorescence-activated cell sorter after antigen...

An R package "VariABEL" for genome-wide searching of potentially interacting loci by testing genotypic variance heterogeneity

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Struchalin Maksim V

2012-01-01

Full Text Available Abstract Background Hundreds of new loci have been discovered by genome-wide association studies of human traits. These studies mostly focused on associations between single locus and a trait. Interactions between genes and between genes and environmental factors are of interest as they can improve our understanding of the genetic background underlying complex traits. Genome-wide testing of complex genetic models is a computationally demanding task. Moreover, testing of such models leads to multiple comparison problems that reduce the probability of new findings. Assuming that the genetic model underlying a complex trait can include hundreds of genes and environmental factors, testing of these models in genome-wide association studies represent substantial difficulties. We and Pare with colleagues (2010 developed a method allowing to overcome such difficulties. The method is based on the fact that loci which are involved in interactions can show genotypic variance heterogeneity of a trait. Genome-wide testing of such heterogeneity can be a fast scanning approach which can point to the interacting genetic variants. Results In this work we present a new method, SVLM, allowing for variance heterogeneity analysis of imputed genetic variation. Type I error and power of this test are investigated and contracted with these of the Levene's test. We also present an R package, VariABEL, implementing existing and newly developed tests. Conclusions Variance heterogeneity analysis is a promising method for detection of potentially interacting loci. New method and software package developed in this work will facilitate such analysis in genome-wide context.

A prospective cohort study comparing the effect of single-dose 2 g metronidazole on Trichomonas vaginalis infection in HIV-seropositive versus HIV-seronegative women.

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Balkus, Jennifer E; Richardson, Barbra A; Mochache, Vernon; Chohan, Vrasha; Chan, Jeannie D; Masese, Linnet; Shafi, Juma; Marrazzo, Jeanne; Farquhar, Carey; McClelland, R Scott

2013-06-01

This analysis compared the frequency of persistent Trichomonas vaginalis (TV) among HIV-seropositive and HIV-seronegative women. Data were obtained from women enrolled in an open cohort study of sex workers in Kenya. Participants were examined monthly, and those diagnosed as having TV by saline microscopy were treated with single-dose 2 g oral metronidazole. All women on antiretroviral therapy (ART) used nevirapine-based regimens. Generalized estimating equations with a logit link were used to compare the frequency of persistent TV (defined as the presence of motile trichomonads by saline microscopy at the next examination visit within 60 days) by HIV status. Three-hundred sixty participants contributed 570 infections to the analysis (282 HIV-seropositive and 288 HIV-seronegative). There were 42 (15%) persistent infections among HIV-seropositive participants versus 35 (12%) among HIV-seronegative participants (adjusted odds ratio, 1.14; 95% confidence interval [CI], 0.70-1.87). Persistent TV was highest among HIV-seropositive women using ART (21/64 [33%]) compared with HIV-seropositive women not using ART (21/217 [10%]). Concurrent bacterial vaginosis (BV) at TV diagnosis was associated with an increased likelihood of persistent TV (adjusted odds ratio, 1.90; 95% confidence interval, 1.16-3.09). The frequency of persistent TV infection after treatment with single-dose 2 g oral metronidazole was similar by HIV status. Alternative regimens including multiday antibiotic treatment may be necessary to improve cure rates for women using nevirapine-based ART and women with TV and concurrent BV.

An in vitro study of antifungal drug susceptibility of Candida species isolated from human immunodeficiency virus seropositive and human immunodeficiency virus seronegative individuals in Lucknow population Uttar Pradesh.

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Dar, Mohammad Shafi; Sreedar, Gadiputi; Shukla, Abhilasha; Gupta, Prashant; Rehan, Ahmad Danish; George, Jiji

2015-01-01

Candidiasis is the most common opportunistic infection in human immunodeficiency virus (HIV) seropositive patients, starting from asymptomatic colonization to pathogenic forms and gradual colonization of non-albicans in patients with advanced immunosuppression leads to resistance for azole group of antifungal drugs with high rate of morbidity and mortality. To isolate the Candida species and determine of antifungal drug susceptibility against fluconazole, itraconazole, nystatin, amphotericin B, and clotrimazolein HIV seropositive and control individuals, with or without clinical oropharyngeal candidiasis (OPC). Includes samples from faucial region of 70 subjects with and without clinical candidiasis in HIV seropositive and controls were aseptically inoculated onto Sabaraud's Dextrose Agar media and yeasts were identified for the specific species by Corn Meal Agar, sugar fermentation and heat tolerance tests. Antifungal drug susceptibility of the isolated species was done against above-mentioned drugs by E-test and disc diffusion method. The commonly isolated species in HIV seropositive and controls were Candida albicans, Candida glabrata and Candida tropicalis Candida guilliermondii and Candida dubliniensis isolated only in HIV seropositive patients. Susceptibility against selected antifungal drugs was observed more in HIV-negative individuals whereas susceptible dose-dependent and resistance were predominant in HIV-positive patients. Resistance is the major problem in the therapy of OPC, especially in HIV seropositive patients due to aggressive and prolonged use of antifungal agents, therefore, our study emphasizes the need for antifungal drug susceptibility testing whenever antifungal treatment is desired, especially in HIV-infected subjects.

[Investigation of Legionella pneumophila seropositivity in the professional long distance drivers as a risky occupation].

Science.gov (United States)

Polat, Yusuf; Ergin, Cağri; Kaleli, Ilknur; Pinar, Ahmet

2007-04-01

Contaminated water sources, reservoirs and systems such as evaporative condensers of air-conditioners are known to be the main transmission routes of Legionella spp. which are ubiquitous aquatic bacteria. By virtue of this point the aim of this study was to investigate the rate of Legionella pneumophila seropositivity in a profession considered as risky due to the direct and prolonged exposure to air-conditioning and air-circulating systems. For this purpose, in the period of February-August 2004 a total of 79 male subjects (63 were bus drivers and 16 were driver assistants) who were continously travelling to two different route (South part as hot climate and Middle/North parts as cold climate of Turkey) from Denizli province coach station (a province located in internal Aegian where accepted as crossroads), were included to the study. The mean age and mean working duration of bus drivers were 43.0 +/- 1.1 years and 20.0 +/- 1.1 years, respectively, while these values were 22.5 +/- 0.9 years and 4.0 +/- 0.6 years, respectively, for the drivers' assistants. The serum samples collected from the subjects were screened by a commercial indirect immunofluorescence method (Euroimmun, Germany) using L. pneumophila serogrup 1-14 antigens for the presence of specific antibodies. Additionally, air-conditioners' moisture exhaust samples of the busses in which seropositive subjects travelling with have been examined by culture and 5S rRNA gene targeted polymerase chain reaction (PCR) methods, for the presence of Legionella spp. The overall L. pneumophila seropositivity rate was detected as 15.2% (12/79). This rate was 19% (12/63) for bus drivers while all of the drivers' assistants were found seronegative. The seropositivity rate was found statistically higher in the personnel who were travelling to the hot climates (10/36, 27.8%) than those who travel to cold climates (2/43, 4.6%), (p travel. Our data indicated that long distance bus drivers were chronically exposed to this

Frontal Neurons Modulate Memory Retrieval across Widely Varying Temporal Scales

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Zhang, Wen-Hua; Williams, Ziv M.

2015-01-01

Once a memory has formed, it is thought to undergo a gradual transition within the brain from short- to long-term storage. This putative process, however, also poses a unique problem to the memory system in that the same learned items must also be retrieved across broadly varying time scales. Here, we find that neurons in the ventrolateral…

Association of serum anti-rotavirus immunoglobulin A antibody seropositivity and protection against severe rotavirus gastroenteritis: analysis of clinical trials of human rotavirus vaccine.

Science.gov (United States)

Cheuvart, Brigitte; Neuzil, Kathleen M; Steele, A Duncan; Cunliffe, Nigel; Madhi, Shabir A; Karkada, Naveen; Han, Htay Htay; Vinals, Carla

2014-01-01

Clinical trials of the human rotavirus vaccine Rotarix™ (RV1) have demonstrated significant reductions in severe rotavirus gastroenteritis (RVGE) in children worldwide. However, no correlate of vaccine efficacy (VE) has yet been established. This paper presents 2 analyses which aimed to investigate whether serum anti-RV IgA measured by ELISA 1 or 2 mo post-vaccination can serve as a correlate of efficacy against RVGE: (1) In a large Phase III efficacy trial (Rota-037), the Prentice criteria for surrogate endpoints was applied to anti-RV IgA seropositivity 1 mo post-vaccination. These criteria determine whether a significant vaccine group effect can be predicted from the surrogate, namely seropositivity (anti-RV IgA concentration>20 U/mL); (2) Among other GSK-sponsored RV1 VE studies, 8 studies which assessed immunogenicity at 1 or 2 mo post-vaccination in all or a sub-cohort of enrolled subjects and had at least 10 RVGE episodes were included in a meta-analysis to measure the regression between clinical VE and VE predicted from immunogenicity (VE1). In Rota-037, anti-RV IgA seropositivity post-vaccination was associated with a lower incidence of any or severe RVGE, however, the proportion of vaccine group effect explained by seropositivity was only 43.6% and 32.7% respectively. This low proportion was due to the vaccine group effect observed in seronegative subjects. In the meta-analysis, the slope of the regression between clinical VE and VE1 was statistically significant. These two independent analyses support the hypothesis that post-vaccination anti-RV IgA seropositivity (antibody concentration ≥20 U/mL) may serve as a useful correlate of efficacy in clinical trials of RV1 vaccines.

Seropositivity of TTIs among blood donors in Hail, Saudi Arabia, from 2014 to 2015

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Yousef Abd El Galil Ahmed Sarah

2016-02-01

Full Text Available Objective: To detect the seropositivity of transfusion transmitted infections among healthy blood donors in Hail Region, Saudi Arabia. Methods: In the study, about 361 blood donors from different nationalities and ages were tested. Serum samples were collected and tested by ELISA for detection of HIV, HTLV-I/II, hepatitis B virus, syphilis and hepatitis C virus (HCV. Results: Out of 361 donors, 26 were found to be positive for HCV in a percentage of 7.2% while 17 (4.7% of them were infected with HIV. There were eight donors infected with HTLV-I/II, and three donors infected with syphilis. Hepatitis B surface antigen was detected in 10% of donors while hepatitis B surface antibody and hepatitis B core antibody were positive in thirty-one blood donors. Conclusions: The obtained data revealed that the seropositivity of hepatitis B virus, HCV, syphilis, HTLV-I/II, and HIV in Hail Region during the period under study were 8.6%, 7.2%, 4.7%, 2.2% and 0.8%, respectively. It is recommended to continue screening blood donors with highly specific and sensitive tests, to counsel donors who are positive to transfusion transmitted infections.

Seropositivity and risk factors associated with Toxoplasma gondii infection in wild birds from Spain.

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Oscar Cabezón

Full Text Available Toxoplasma gondii is a zoonotic intracellular protozoan parasite of worldwide distribution that infects many species of warm-blooded animals, including birds. To date, there is scant information about the seropositivity of T. gondii and the risk factors associated with T. gondii infection in wild bird populations. In the present study, T. gondii infection was evaluated on sera obtained from 1079 wild birds belonging to 56 species (including Falconiformes (n=610, Strigiformes (n=260, Ciconiiformes (n=156, Gruiformes (n=21, and other orders (n=32, from different areas of Spain. Antibodies to T. gondii (modified agglutination test, MAT titer ≥1:25 were found in 282 (26.1%, IC(95%:23.5-28.7 of the 1079 birds. This study constitute the first extensive survey in wild birds species in Spain and reports for the first time T. gondii antibodies in the griffon vulture (Gyps fulvus, short-toed snake-eagle (Circaetus gallicus, Bonelli's eagle (Aquila fasciata, golden eagle (Aquila chrysaetos, bearded vulture (Gypaetus barbatus, osprey (Pandion haliaetus, Montagu's harrier (Circus pygargus, Western marsh-harrier (Circus aeruginosus, peregrine falcon (Falco peregrinus, long-eared owl (Asio otus, common scops owl (Otus scops, Eurasian spoonbill (Platalea leucorodia, white stork (Ciconia ciconia, grey heron (Ardea cinerea, common moorhen (Gallinula chloropus; in the International Union for Conservation of Nature (IUCN "vulnerable" Spanish imperial eagle (Aquila adalberti, lesser kestrel (Falco naumanni and great bustard (Otis tarda; and in the IUCN "near threatened" red kite (Milvus milvus. The highest seropositivity by species was observed in the Eurasian eagle owl (Bubo bubo (68.1%, 98 of 144. The main risk factors associated with T. gondii seropositivity in wild birds were age and diet, with the highest exposure in older animals and in carnivorous wild birds. The results showed that T. gondii infection is widespread and can be at a high level in many wild

Time-varying BRDFs.

Science.gov (United States)

Sun, Bo; Sunkavalli, Kalyan; Ramamoorthi, Ravi; Belhumeur, Peter N; Nayar, Shree K

2007-01-01

The properties of virtually all real-world materials change with time, causing their bidirectional reflectance distribution functions (BRDFs) to be time varying. However, none of the existing BRDF models and databases take time variation into consideration; they represent the appearance of a material at a single time instance. In this paper, we address the acquisition, analysis, modeling, and rendering of a wide range of time-varying BRDFs (TVBRDFs). We have developed an acquisition system that is capable of sampling a material's BRDF at multiple time instances, with each time sample acquired within 36 sec. We have used this acquisition system to measure the BRDFs of a wide range of time-varying phenomena, which include the drying of various types of paints (watercolor, spray, and oil), the drying of wet rough surfaces (cement, plaster, and fabrics), the accumulation of dusts (household and joint compound) on surfaces, and the melting of materials (chocolate). Analytic BRDF functions are fit to these measurements and the model parameters' variations with time are analyzed. Each category exhibits interesting and sometimes nonintuitive parameter trends. These parameter trends are then used to develop analytic TVBRDF models. The analytic TVBRDF models enable us to apply effects such as paint drying and dust accumulation to arbitrary surfaces and novel materials.

Genome-wide CpG island methylation and intergenic demethylation propensities vary among different tumor sites.

Science.gov (United States)

Lee, Seung-Tae; Wiemels, Joseph L

2016-02-18

The epigenetic landscape of cancer includes both focal hypermethylation and broader hypomethylation in a genome-wide manner. By means of a comprehensive genomic analysis on 6637 tissues of 21 tumor types, we here show that the degrees of overall methylation in CpG island (CGI) and demethylation in intergenic regions, defined as 'backbone', largely vary among different tumors. Depending on tumor type, both CGI methylation and backbone demethylation are often associated with clinical, epidemiological and biological features such as age, sex, smoking history, anatomic location, histological type and grade, stage, molecular subtype and biological pathways. We found connections between CGI methylation and hypermutability, microsatellite instability, IDH1 mutation, 19p gain and polycomb features, and backbone demethylation with chromosomal instability, NSD1 and TP53 mutations, 5q and 19p loss and long repressive domains. These broad epigenetic patterns add a new dimension to our understanding of tumor biology and its clinical implications. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Diarrhoea-associated parasites in HIV-1 seropositive and sero-negative patients in a teaching hospital, Northwest Ethiopia.

Science.gov (United States)

Andualem, Berhanu; Kassu, Afework; Moges, Feleke; Gedefaw, Molla; Diro, Ermias; Mengistu, Getahun; Andargie, Gashaw

2007-04-01

to determine the prevalence and type of intestinal parasites in HIV infected and uninfected patients with diarrhea. A cross-sectional study was conducted at Gondar University hospital, Northwest Ethiopia, between March 2003 and October 2004. A total 312 consecutive diarrheic patients were included in the study. Stool specimens were collected and examined for intestinal parasites following direct, formol-ether concentration and modified acid fast staining methods. Among the patients, 63.8% were found to be HIV seropositive. The prevalence of intestinal parasites in HIV seropositive and seronegative diarrheic patients was 30.6% and 33.6%, respectively. The most prevalent parasites were Strongyoides stercoralis (9.0%) and Entamoeba histolytica (8.3%) followed by Ascaris lumbricoides (5.4%) and Cryptosporidium species (5. 1%). The prevalence of intestinal parasites in diarrheic patients was very high. Institution of appropriate intervention measures are needed to reduce morbidity in such patients.

Detection and gB genotyping of CMV in Mexican preterm infants in the context of maternal seropositivity.

Science.gov (United States)

Arellano-Galindo, José; Villanueva-García, Dina; Cruz-Ramirez, José Luis; Yalaupari-Mejìa, Juan Pablo; Uribe-Gutiérrez, Gabriel; Velazquez-Guadarrama, Norma; Nava-Frias, Margarita; Munoz-Hernández, Onofre; Mejía-Arangure, Juan Manuel

2014-06-11

Congenital (CI) and perinatal cytomegalovirus (CMV) infections (PI) can be linked to maternal CMV seropositivity, with fatal consequences in preterm newborns. GB genotyping has been used to analyze genotypic similarity in mothers and infants. The frequency of CMV infection in the context of maternal seropositivity and the viral gB genotypes as well as the genotypic similarity in mothers and preterm infants were investigated. Saliva samples and dry blood spots (DBS) were taken weekly from preterm newborns  from birth until the first month of life, and breast milk samples were taken from their mothers weekly during the first month of lactation. CMV IgG seroprevalence of the mothers and CI or PI in the infants were established. The gB status and genotypic similarities were established retrospectively in DBS and in the breast milk samples. In total, 387 neonates and 375 mothers were enrolled. The maternal CMV-positive IgG serology was 97.3% (365/375). Neonatal CMV was found in 5.1% (20/387) of newborns, and one infant presented with CMV-compatible symptoms. CI was 2.5% and PI in the first month after birth was 11.8%. GB2 was the most prevalent genotype and was also the genotype preferentially transmitted to newborns by mothers with mixed infections. CMV PI and CI in preterm infants from highly seropositive mothers was high, but the rate of symptomatic infection was low. The prevalent genotype was gB2, and this genotype was preferentially transmitted to newborns by mothers with mixed infections.

Reproduction in porcine circovirus type 2 (PCV2 seropositive gilts inseminated with PCV2b spiked semen

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Sarli Giuseppe

2012-08-01

Full Text Available Abstract Background Since 1999, field evidence of transplacental infection by porcine circovirus type 2 (PCV2 and reproductive failure has been reported in pigs. The objective of this study was to evaluate the clinical and pathological consequences of PCV2 infection in conventional PCV2-seropositive gilts by insemination with PCV2b-spiked semen. Results Six PCV2 seropositive gilts were inseminated with PCV2b-supplemented semen (infected and three animals with semen and cell culture medium (controls. Only three out of the six infected animals were pregnant by ultrasonography on day 29 after insemination, while two out of the three controls were pregnant. One control gilt aborted on day 23 after insemination but not due to PVC2. Viraemia was demonstrated in four out of six infected and in one control gilt that became infected with PCV2a. Anti-PCV2 antibody titres showed dynamic variations in the infected group throughout the study. Among infected gilts, the animal with the lowest anti-PCV2 titre (1/100 at the beginning of the experiment and another that reached a similar low value during the experiment showed evident seroconversion over time and had also PCV2 positive foetuses. One placenta displayed mild focal necrosis of the chorionic epithelium positively stained by immunohistochemistry for PCV2 antigen. Conclusions PCV2-seropositive gilts can be infected with PCV2 after intrauterine exposure and low maternal antibody titre may increase the probability of a foetal infection.

The correlation between HIV seropositivity, cervical dysplasia, and HPV subtypes 6/11, 16/18, 31/33/35

DEFF Research Database (Denmark)

Tweddel, G; Heller, P; Cunnane, M

1994-01-01

Twenty-one human immunodeficiency virus (HIV) seropositive patients were studied to determine the prevalence of cervical dysplasia, the distribution of human papilloma virus (HPV) subtypes, and the utility of cytologic diagnosis in this population. The patients ranged in age from 18 to 41 years...

Delayed LGI1 seropositivity in voltage-gated potassium channel (VGKC)-complex antibody limbic encephalitis

OpenAIRE

Sweeney, Michael; Galli, Jonathan; McNally, Scott; Tebo, Anne; Haven, Thomas; Thulin, Perla; Clardy, Stacey L

2017-01-01

We utilise a clinical case to highlight why exclusion of voltage-gated potassium channel (VGKC)-complex autoantibody testing in serological evaluation of patients may delay or miss the diagnosis. A 68-year-old man presented with increasing involuntary movements consistent with faciobrachial dystonic seizures (FBDS). Initial evaluation demonstrated VGKC antibody seropositivity with leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) seronegativity. Aggress...

Polyarthropathy in a cat seropositive for feline synctial-forming virus and feline immunodeficiency virus

International Nuclear Information System (INIS)

Becker, K.M.; Brown, N.O.; Denardo, G.

1994-01-01

A four-year-old, neutered male, domestic shorthair cat presented witha polyarthropathy. Indirect immunofluorescence assays revealed seropositive results for both feline synctial-forming virus (FeSFV) and feline immunodeficiency virus (FIV). Direct relationships between viral infections and polyarthropathy are not confirmed, however, possible correlations are discussed. Mechanisms of lentivirus infections and polyarthropathy in the cat are reviewed in order to theorize a potential relationship among these disease processes

Prevalence of HCV, HBV, and HIV Seropositivity among Cadavers Referred to Autopsy Hall of Legal Medicine Bureau of Tehran, Iran

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Jaber Gharehdaghi

2017-01-01

Full Text Available A large number of dead bodies are referred to forensic autopsy halls for medicolegal examination. They can be a source of transmission of infectious diseases through direct contact or autopsy tools. The main aim of this study was to estimate the virus infection rates in the dead bodies. One thousand consecutive dead bodies that had been referred to autopsy hall of Legal Medicine Bureau of Tehran, Iran, during 2016, were included. The blood samples were analyzed in the laboratory for detection of HBs Ag, HBs Ab, HIV Ab, and HCV Ab, after providing informed consent from legal next of kin of the dead bodies. The general characteristics of the dead bodies were also collected by a checklist. Forty-seven cases of HIV seropositivity, 80 cases of HBs Ag seropositivity, and 97 cases for HCV Ab seropositivity were found. Among them, 27 cases of HIV, 40 cases of anti-HBC positive, and 94 cases of RIBA testing positive for HCV were proved through confirmatory tests. In other words, 2.6% of the dead bodies were infected with HIV, 3.8% with HBV, and 9% with HCV. The total infection rate was 15.5%. This is a worrying risk for pathologist and autopsy technicians.

Prevalence of HCV, HBV, and HIV Seropositivity among Cadavers Referred to Autopsy Hall of Legal Medicine Bureau of Tehran, Iran.

Science.gov (United States)

Gharehdaghi, Jaber; Abedi Khorasgani, Mohammad Hassan; Ghadiani, Mohammad Hassan; Kazemifar, Amir Mohammad; Solhi, Hassan; Solhi, Sadra

2017-01-01

A large number of dead bodies are referred to forensic autopsy halls for medicolegal examination. They can be a source of transmission of infectious diseases through direct contact or autopsy tools. The main aim of this study was to estimate the virus infection rates in the dead bodies. One thousand consecutive dead bodies that had been referred to autopsy hall of Legal Medicine Bureau of Tehran, Iran, during 2016, were included. The blood samples were analyzed in the laboratory for detection of HBs Ag, HBs Ab, HIV Ab, and HCV Ab, after providing informed consent from legal next of kin of the dead bodies. The general characteristics of the dead bodies were also collected by a checklist. Forty-seven cases of HIV seropositivity, 80 cases of HBs Ag seropositivity, and 97 cases for HCV Ab seropositivity were found. Among them, 27 cases of HIV, 40 cases of anti-HBC positive, and 94 cases of RIBA testing positive for HCV were proved through confirmatory tests. In other words, 2.6% of the dead bodies were infected with HIV, 3.8% with HBV, and 9% with HCV. The total infection rate was 15.5%. This is a worrying risk for pathologist and autopsy technicians.

Peru-15 (Choleragarde(®)), a live attenuated oral cholera vaccine, is safe and immunogenic in human immunodeficiency virus (HIV)-seropositive adults in Thailand.

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Ratanasuwan, W; Kim, Y H; Sah, B K; Suwanagool, S; Kim, D R; Anekthananon, A; Lopez, A L; Techasathit, W; Grahek, S L; Clemens, J D; Wierzba, T F

2015-09-11

Many areas with endemic and epidemic cholera report significant levels of HIV transmission. According to the World Health Organization (WHO), over 95% of reported cholera cases occur in Africa, which also accounts for nearly 70% of people living with HIV/AIDS globally. Peru-15, a promising single dose live attenuated oral cholera vaccine (LA-OCV), was previously found to be safe and immunogenic in cholera endemic areas. However, no data on the vaccine's safety among HIV-seropositive adults had been collected. This study was a double-blinded, individually randomized, placebo-controlled trial enrolling HIV-seropositive adults, 18-45 years of age, conducted in Bangkok, Thailand, to assess the safety of Peru-15 in a HIV-seropositive cohort. 32 HIV infected subjects were randomized to receive either a single oral dose of the Peru-15 vaccine with a buffer or a placebo (buffer only). No serious adverse events were reported during the follow-up period in either group. The geometric mean fold (GMF) rise in V. cholerae O1 El Tor specific antibody titers between baseline and 7 days after dosing was 32.0 (pcholerae was isolated from the stool of one vaccinee, and found to be genetically identical to the Peru-15 vaccine strain. There were no significant changes in HIV viral load or CD4 T-cell counts between vaccine and placebo groups. Peru-15 was shown to be safe and immunogenic in HIV-seropositive Thai adults. Copyright © 2015 Elsevier Ltd. All rights reserved.

Is there a link between seropositivity to Helicobacter pylori and hepatitis A virus? A systematic review.

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BinSaeed, Abdulaziz A

2010-07-01

Since hepatitis A virus (HAV) is acquired primarily through the fecal-oral pathway, several investigators have used HAV seropositivity as a proxy for exposure to this pathway. This paper is a critical review of the evidence relevant to the association between seropositivity to HAV and Helicobacter pylori, and considers the validity of comparisons for testing the hypothesis that H. pylori spreads by the fecal-oral route. A Medline search identified reports of all types published in the English language literature that were linked to the keywords 'Campylobacter pylori', 'hepatitis A', or 'Helicobacter pylori', cross-referenced with 'seroepidemiology', 'seroprevalence', or 'seropositivity'. Studies identified by the search were included in the review if they used specific IgG antibodies to classify the serostatus of subjects for both HAV and H. pylori infection and provided an estimate of the magnitude of the association between HAV and H. pylori or information that permitted calculation of an odds ratio (OR). Out of the 21 studies identified, 15 met the inclusion criteria. The studies showed ORs for an association of HAV and H. pylori that ranged from 0.81 to 8.4. After adjustment for potential confounders, ORs shifted toward the null. They also showed that HAV seroprevalence is lower than H. pylori seroprevalence in early life and then becomes higher in later life. Thus in most populations, the trends cross over at some point. The observed associations between the two infections are generally overestimated by the confounding effects of age and socio-economic status-related factors, and when these factors are controlled, the association becomes weak. Moreover, HAV infection elicits a long-term antibody response, while H. pylori infection does not. Consequently, serostatus comparison does not constitute a convincing test of the fecal-oral transmission hypothesis for H. pylori. Copyright 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All

MicroRNA profile changes in human immunodeficiency virus type 1 (HIV-1 seropositive individuals

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Smith Stephen M

2008-12-01

Full Text Available Abstract MicroRNAs (miRNAs play diverse roles in regulating cellular and developmental functions. We have profiled the miRNA expression in peripheral blood mononuclear cells from 36 HIV-1 seropositive individuals and 12 normal controls. The HIV-1-positive individuals were categorized operationally into four classes based on their CD4+ T-cell counts and their viral loads. We report that specific miRNA signatures can be observed for each of the four classes.

Five different tests of reaction time evaluated in HIV seropositive men.

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Dunlop, O; Bjørklund, R A; Abdelnoor, M; Myrvang, B

1992-09-01

In an attempt to develop a short neuropsychological test battery five different tests of reaction time were assessed according to their ability to discriminate between HIV seropositive men and healthy controls. In all tests a patient group with clinical symptoms was slower than the control group. In the complex reaction time test, which has a large cognitive aspect, even a clinically "asymptomatic" group was slower than the control group. The movement test, a new test with a large motor component, identified most slow responders, defining approximately half of the patients with clinical symptoms and one third of the "asymptomatic" patients as such. A test battery consisting of three tests is suggested for serial assessment and screening.

Comparison of risk factors for seropositivity to feline immunodeficiency virus and feline leukemia virus among cats: a case-case study.

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Chhetri, Bimal K; Berke, Olaf; Pearl, David L; Bienzle, Dorothee

2015-02-10

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are reported to have similar risk factors and similar recommendations apply to manage infected cats. However, some contrasting evidence exists in the literature with regard to commonly reported risk factors. In this study, we investigated whether the known risk factors for FIV and FeLV infections have a stronger effect for either infection. This retrospective study included samples from 696 cats seropositive for FIV and 593 cats seropositive for FeLV from the United States and Canada. Data were collected during two cross sectional studies, where cats were tested using IDEXX FIV/FeLV ELISA kits. To compare the effect of known risk factors for FIV infection compared to FeLV, using a case-case study design, random intercept logistic regression models were fit including cats' age, sex, neuter status, outdoor exposure, health status and type of testing facility as independent variables. A random intercept for testing facility was included to account for clustering expected in testing practices at the individual clinics and shelters. In the multivariable random intercept model, the odds of FIV compared to FeLV positive ELISA results were greater for adults (OR = 2.09, CI: 1.50-2.92), intact males (OR = 3.14, CI: 1.85-3.76), neutered males (OR = 2.68, CI: 1.44- 3.14), cats with outdoor access (OR = 2.58, CI: 1.85-3.76) and lower for cats with clinical illness (OR = 0.60, 95% CI: 0.52-0.90). The variance components obtained from the model indicated clustering at the testing facility level. Risk factors that have a greater effect on FIV seropositivity include adulthood, being male (neutered or not) and having access to outdoors, while clinical illness was a stronger predictor for FeLV seropositivity. Further studies are warranted to assess the implications of these results for the management and control of these infections.

Persistent seropositivity for yellow fever in a previously vaccinated autologous hematopoietic stem cell transplantation recipient.

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Hayakawa, Kayoko; Takasaki, Tomohiko; Tsunemine, Hiroko; Kanagawa, Shuzo; Kutsuna, Satoshi; Takeshita, Nozomi; Mawatari, Momoko; Fujiya, Yoshihiro; Yamamoto, Kei; Ohmagari, Norio; Kato, Yasuyuki

2015-08-01

The duration of a protective level of yellow fever antibodies after autologous hematopoietic stem cell transplantation in a previously vaccinated person is unclear. The case of a patient who had previously been vaccinated for yellow fever and who remained seropositive for 22 months after autologous peripheral blood stem cell transplantation for malignant lymphoma is described herein. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Melanocyte biology and function with reference to oral melanin hyperpigmentation in HIV-seropositive subjects.

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Feller, Liviu; Chandran, Rakesh; Kramer, Beverley; Khammissa, Razia A G; Altini, Mario; Lemmer, Johan

2014-09-01

The color of normal skin and of oral mucosa is not determined by the number of melanocytes in the epithelium but rather by their melanogenic activity. Pigmented biopolymers or melanins are synthesized in melanosomes. Tyrosinase is the critical enzyme in the biosynthesis of both brown/black eumelanin and yellow/red pheomelanin. The number of the melanosomes within the melanocytes, the type of melanin within the melanosomes, and the efficacy of the transfer of melanosomes from the melanocytes to the neighboring keratinocytes all play an important role in tissue pigmentation. Melanin production is regulated by locally produced factors including proopiomelanocortin and its derivative peptides, particularly alpha-melanocyte-stimulating hormone (α-MSH), melanocortin 1 receptor (MC1R), adrenergic and cholinergic agents, growth factors, cytokines, and nitric oxide. Both eumelanin and pheomelanin can be produced by the same melanocytes, and the proportion of the two melanin types is influenced by the degree of functional activity of the α-MSH/MC1R intracellular pathway. The cause of HIV oral melanosis is not fully understood but may be associated with HIV-induced cytokine dysregulation, with the medications commonly prescribed to HIV-seropositive persons, and with adrenocortical dysfunction, which is not uncommon in HIV-seropositive subjects with AIDS. The purpose of this article is to discuss some aspects of melanocyte biology and HIV-associated oral melanin hyperpigmentation.

Long-term survival of an urban fruit bat seropositive for Ebola and Lagos bat viruses.

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David T S Hayman

2010-08-01

Full Text Available Ebolaviruses (EBOV (family Filoviridae cause viral hemorrhagic fevers in humans and non-human primates when they spill over from their wildlife reservoir hosts with case fatality rates of up to 90%. Fruit bats may act as reservoirs of the Filoviridae. The migratory fruit bat, Eidolon helvum, is common across sub-Saharan Africa and lives in large colonies, often situated in cities. We screened sera from 262 E. helvum using indirect fluorescent tests for antibodies against EBOV subtype Zaire. We detected a seropositive bat from Accra, Ghana, and confirmed this using western blot analysis. The bat was also seropositive for Lagos bat virus, a Lyssavirus, by virus neutralization test. The bat was fitted with a radio transmitter and was last detected in Accra 13 months after release post-sampling, demonstrating long-term survival. Antibodies to filoviruses have not been previously demonstrated in E. helvum. Radio-telemetry data demonstrates long-term survival of an individual bat following exposure to viruses of families that can be highly pathogenic to other mammal species. Because E. helvum typically lives in large urban colonies and is a source of bushmeat in some regions, further studies should determine if this species forms a reservoir for EBOV from which spillover infections into the human population may occur.

HIV, malaria, and infant anemia as risk factors for postneonatal infant mortality among HIV-seropositive women in Kisumu, Kenya

NARCIS (Netherlands)

van Eijk, Anna M.; Ayisi, John G.; ter Kuile, Feiko O.; Slutsker, Laurence; Shi, Ya Ping; Udhayakumar, Venkatachalam; Otieno, Juliana A.; Kager, Piet A.; Lal, Renu B.; Steketee, Richard W.; Nahlen, Bernard L.

2007-01-01

BACKGROUND: HIV and malaria in sub-Saharan Africa are associated with poor pregnancy outcome and infant survival. We studied the association of placental malaria, infant malaria and anemia, and infant HIV status with postneonatal infant mortality (PNIM) among infants of HIV-seropositive women.

Identification of Candida dubliniensis in a study of HIV-seropositive pediatric dental patients.

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Brown, D M; Jabra-Rizk, M A; Falkler, W A; Baqui, A A; Meiller, T F

2000-01-01

The combination of an immature immune system and suppressed cellular immunity in children with HIV infections provides optimal conditions for rapid disease progression. As a result, pediatric AIDS has become a major epidemiological challenge. Oral fungal colonization remains one of the most common opportunistic infections observed in both adult and pediatric HIV infected patients. Although Candida albicans is the most frequently isolated opportunistic fungal species, a recently characterized Candida species, C. dubliniensis, has gained considerable attention due to its almost exclusive association with HIV-seropositive individuals. The purpose of this study was to prospectively screen for the presence of C. dubliniensis among pediatric HIV+ patients. Oral samples taken from twenty-seven children were cultured for the presence of yeast. All positive yeast isolates obtained were screened for the presence of C. dubliniensis by use of tests for germ tube and chlamydospore production, detection of inability to grow at 45 degrees C, by colony color on CHROMagar Candida medium, coaggregation with Fusobacterium nucleatum ATCC 49256 and by the results of sugar assimilation testing with the API 20C AUX yeast identification system. Among the 27 patients tested, 3 patients were found to harbor C. dubliniensis, one of which also grew C. glabrata; 12 patients were colonized with C. albicans, while the remaining 12 patients were negative for yeast. Identification of the three C. dubliniensis isolates was genetically confirmed by electrophoretic karyotyping. All three C. dubliniensis isolates were found to be susceptible to fluconazole (MIC pediatric HIV seropositive population and support the need for further investigation into the prevalence and pathogenesis of C. dubliniensis.

Barriers to uptake of prevention of mother-to-child transmission of HIV services among mothers of vertically infected HIV-seropositive infants in Makurdi, Nigeria

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Anígilájé EA

2016-01-01

Full Text Available Emmanuel Ademola Anígilájé,1 Bem Ruben Ageda,2 Nnamdi Okechukwu Nweke1 1Department of Paediatrics, 2Department of Obstetrics and Gynaecology, Federal Medical Centre, Makurdi, Nigeria Background: Perinatal transmission of human immunodeficiency virus (HIV continues in Nigeria because of the poor use of prevention of mother-to-child transmission of HIV (PMTCT services. This study reports on the barriers preventing mothers of vertically infected HIV-seropositive infants to use the PMTCT services at the Federal Medical Centre, Makurdi, Nigeria.Methods: This is a descriptive study conducted between January and April, 2014. A quantitative survey was applied to detect barriers along the PMTCT services cascade among 52 mothers of vertically infected HIV-seropositive infants. This includes 22 women who attended antenatal care at the Federal Medical Centre (designated as Group A mothers and 30 women who did not receive any form of PMTCT service (Group B mothers. The study was supplemented with a focused group discussion involving 12 discussants from the two groups.Results: In the quantitative assessment: among the Group A mothers, falling asleep was the most common reason (n=22, 100% for missing therapeutic/prophylactic antiretroviral medicine; financial constraint (n=22, 100% was the most common reason for antenatal care visit defaults; and a lot of the mothers (n=11, 50.0% did not give nevirapine to their newborns because they delivered at home. Among Group B mothers, unawareness of HIV-seropositive status was the most common reason (n=28, 93.3% given for not accessing PMTCT services. In the qualitative study: noninvolvement of male partners, stigma and discrimination experienced by HIV-seropositive mothers, financial constraints in couples, involvement of traditional birth attendants in antenatal care and delivery of HIV-infected women, unawareness of HIV-seropositive status by pregnant women, poor health system, and the lack of funding for PMTCT

No Serologic Evidence of Middle East Respiratory Syndrome Coronavirus Infection Among Camel Farmers Exposed to Highly Seropositive Camel Herds: A Household Linked Study, Kenya, 2013.

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Munyua, Peninah; Corman, Victor Max; Bitek, Austine; Osoro, Eric; Meyer, Benjamin; Müller, Marcel A; Lattwein, Erik; Thumbi, S M; Murithi, Rees; Widdowson, Marc-Alain; Drosten, Christian; Njenga, M Kariuki

2017-06-01

AbstractHigh seroprevalence of Middle East respiratory syndrome coronavirus (MERS-CoV) among camels has been reported in Kenya and other countries in Africa. To date, the only report of MERS-CoV seropositivity among humans in Kenya is of two livestock keepers with no known contact with camels. We assessed whether persons exposed to seropositive camels at household level had serological evidence of infection. In 2013, 760 human and 879 camel sera were collected from 275 and 85 households respectively in Marsabit County. Data on human and animal demographics and type of contact with camels were collected. Human and camel sera were tested for anti-MERS-CoV IgG using a commercial enzyme-linked immunosorbent assay (ELISA) test. Human samples were confirmed by plaque reduction neutralization test (PRNT). Logistic regression was used to identify factors associated with seropositivity. The median age of persons sampled was 30 years (range: 5-90) and 50% were males. A quarter (197/760) of the participants reported having had contact with camels defined as milking, feeding, watering, slaughtering, or herding. Of the human sera, 18 (2.4%) were positive on ELISA but negative by PRNT. Of the camel sera, 791 (90%) were positive on ELISA. On univariate analysis, higher prevalence was observed in female and older camels over 4 years of age ( P MERS-CoV infection among camel pastoralists in Marsabit County. The high seropositivity suggests that MERS-CoV or other closely related virus continues to circulate in camels and highlights ongoing potential for animal-to-human transmission.

A randomized clinical trial comparing cervical dysplasia treatment with cryotherapy vs loop electrosurgical excision procedure in HIV-seropositive women from Johannesburg, South Africa.

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Smith, Jennifer S; Sanusi, Busola; Swarts, Avril; Faesen, Mark; Levin, Simon; Goeieman, Bridgette; Ramotshela, Sibongile; Rakhombe, Ntombiyenkosi; Williamson, Anna L; Michelow, Pam; Omar, Tanvier; Hudgens, Michael G; Firnhaber, Cynthia

2017-08-01

Mortality associated with cervical cancer is a public health concern for women, particularly in HIV-seropositive women in resource-limited countries. HIV-seropositive women are at a higher risk of high-grade cervical precancer, which can eventually progress to invasive carcinoma as compared to HIV-seronegative women. It is imperative to identify effective treatment methods for high-grade cervical precursors among HIV-seropositive women. Randomized controlled trial data are needed comparing cryotherapy vs loop electrosurgical excision procedure treatment efficacy in HIV-seropositive women. Our primary aim was to compare the difference in the efficacy of loop electrosurgical excision procedure vs cryotherapy for the treatment of high-grade cervical intraepithelial neoplasia (grade ≥2) among HIV-seropositive women by conducting a randomized clinical trial. HIV-seropositive women (n = 166) aged 18-65 years with histology-proven cervical intraepithelial neoplasia grade ≥2 were randomized (1:1) to cryotherapy or loop electrosurgical excision procedure treatment at a government hospital in Johannesburg. Treatment efficacy was compared using 6- and 12-month cumulative incidence posttreatment of: (1) cervical intraepithelial neoplasia grade ≥2; (2) secondary endpoints of histologic cervical intraepithelial neoplasia grade ≥3 and grade ≥1; and (3) high-grade and low-grade cervical cytology. The study was registered (ClinicalTrials.govNCT01723956). From January 2010 through August 2014, 166 participants were randomized (86 loop electrosurgical excision procedure; 80 cryotherapy). Cumulative cervical intraepithelial neoplasia grade ≥2 incidence was higher for cryotherapy (24.3%; 95% confidence interval, 16.1-35.8) than loop electrosurgical excision procedure at 6 months (10.8%; 95% confidence interval, 5.7-19.8) (P = .02), although by 12 months, the difference was not significant (27.2%; 95% confidence interval, 18.5-38.9 vs 18.5%; 95% confidence interval, 11

Seropositivity diagnosis for hantavirus in Jataí, Goiás State, Brazil

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Marcos Lázaro Moreli

Full Text Available Abstract INTRODUCTION: Emerging diseases are of great interest, especially those associated with high mortality rates such as hantaviruses. We aimed to conduct a seroepidemiological survey to determine the levels of hantavirus infection. METHODS: In-house enzyme-linked immunosorbent assay (ELISA was used to detect specific antibodies. RESULTS: Of the 429 samples collected, seropositivity of 3.9% to anti-hantavirus immunoglobulin G (IgG was observed (CI 95%: 2.3-5.7. Moreover, in three cases, immunoglobulin M (IgM was detected, of which two were diagnosed as hantavirus cardiopulmonary syndrome (HCPS. CONCLUSIONS: Our data indicate the considerable occurrence of previous hantavirus infections, highlighting occurrences from sub-clinical cases to HCPS.

A study of HIV seropositivity with various clinical manifestation of herpes zoster among patients from Karnataka, India.

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Naveen, Kikkeri Narayanashetty; Tophakane, R S; Hanumanthayya, Keloji; Pv, Bhagawat; Pai, Varadraj V

2011-12-15

To study the various clinical presentations of herpes zoster and to find out the proportion of HIV positivity in these patients. A time bound study was conducted from November 2004 to October 2005. All clinically diagnosed cases of herpes zoster were tested for HIV infection with ELISA and confirmed by Tridot and Coomb AID. Total numbers of 90 zoster cases were recorded. Mean duration of pre herpetic neuralgia was 2.134 (standard deviation=1.424, F=8.951, Psacral (6.66%) nerves. A substantial proportion, 34 (37.77%) out of 90 cases, were found to be HIV positive. Of these, 64.7 percent of the HIV seropositive herpes zoster patients belonged to the age group of 21-40 years. Out of 39 who had a risk of exposure to STDs and whose ages were less than 50 years, 31 (79.48%) tested positive for HIV infection. The occurrence of zoster in the young age group in patients who report a history of risk factors for HIV, may need testing. Herpes zoster serves as a clinical indicator of HIV seropositivity and one of the earliest manifestations.

Calibration device for wide range monitor

International Nuclear Information System (INIS)

Kodoku, Masaya; Sato, Toshifumi.

1989-01-01

The calibration device for a wide range monitor according to the present invention can continuously calibrate the entire counting regions of a wide range monitor. The wide range monitor detect the reactor power in the neutron source region by means of a pulse counting method and detects the reactor power in the intermediate region by means of a cambell method. A calibration signal outputting means is disposed for continuously outputting, as such calibration signals, pulse number varying signals in which the number of pulses per unit time varies depending on the reactor power in the neutron source region to be simulated and amplitude square means varying signal in which the mean square value of amplitude varies depending on the reactor power in the intermediate region to be simulated. By using both of the calibration signals, calibration can be conducted for the nuclear reactor power in the neutron source region and the intermediate region even if the calibration is made over two regions, further, calibration for the period present over the two region can be conducted easily as well. (I.S.)

Firocoxib on aqueous humor prostaglandin E 2 levels for controlling experimentally-induced breakdown of blood-aqueous barrier in healthy and Toxoplasma gondii -seropositive cats

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Deise Cristine Schroder

2016-06-01

Full Text Available ABSTRACT: This study aimed to evaluate the effects of firocoxib for controlling experimentally-induced breakdown of the blood-aqueous barrier in healthy and Toxoplasma gondii -seropositive cats. Thirty two cats with no ocular abnormalities were used. Groups (n=8/each were formed with healthy cats that received 5mg g-1 of oral firocoxib (FH or no treatment (CH on day 0; seropositive cats for anti -T. gondii specific immunoglobulin G (IgG were grouped (n=8/each and treated in a similar fashion (FT and CT. On day 1, cats of all groups received the same treatment protocol, and 1h later, aqueocentesis was performed under general anesthesia (M0. Following 1h, the same procedure was repeated (M1. Quantitation of aqueous humor total protein and prostaglandin E2 (PGE2 were determined. Aqueous samples of seropositive cats were tested for anti- T. gondii specific IgG. In M0, aqueous samples of CT showed a significantly higher concentration of PGE2 in comparison with other groups (P<0.05. In all groups, PGE2 concentration increased significantly from M0 to M1 (P=0.001. PGE2 values did not change significantly between groups in M1 (P=0.17. Anti- T. gondii specific IgG were reported only in samples of M1, and aqueous titers did not change significantly between FT and CT (P=0.11. Although we have observed that aqueous humor PGE2 levels were significantly higher in cats of CT group during M0, such increase was not able to break the blood-aqueous barrier and cause anterior uveitis. Firocoxib did not prevent intraocular inflammation after aqueocentesis, in healthy and toxoplasmosis-seropositive cats.

Study of personality traits, individual coping resources, and their association in HIV-seropositive males

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Prateek Yadav

2017-01-01

Full Text Available Background: HIV infection is an unfortunate consequence of a defined set of behaviors. Individuals with continued high-risk behavior either due to personality factors or due to maladaptive coping skills have higher viral loads and morbidity. Research has shown significant interactions between less effective coping styles and personality factors. Aim: This study aimed to evaluate personality traits, coping skills, and their association in male HIV-seropositive cases. Materials and Methods: This was a cross-sectional study, conducted on 86 patients. Informed consent and sociodemographic details, by a structured questionnaire, were obtained. Scales pertaining to personality factors and coping were applied. Statistical analysis was done by SPSS 16. Results: Neuroticism, extraversion, and conscientiousness traits were in the average range. Scores on openness and agreeableness were below average. The results pertaining to coping showed an overall mean score of 50.78, with the highest on physical domain and then on the philosophical domain, the lowest was in social domain. The research sample perceived their coping resources as average. Neuroticism was negatively related to all the coping styles. Extraversion showed relation with physical, emotional, social, and philosophical scales. Openness was related to philosophical and emotional scales. Agreeableness correlated with all domains of coping except the social. Conscientiousness correlated significantly with all the domains of coping. Conclusion: The various personality traits associated with male HIV-seropositive patients were identified and various coping resources used by these were also delineated. Further, the association among them was identified which can help in primary prevention and mental health professionals to have a targeted approach for counseling.

Candida Species Prevalence Profile in HIV Seropositive Patients from a Major Tertiary Care Hospital in New Delhi, India

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Monika Maheshwari

2016-01-01

Full Text Available Candida is a common opportunistic pathogen during the course of human immunodeficiency virus (HIV disease progression. Changes in the clinical severity of candidiasis and the Candida species prevalence profile may be a reflection of immunological changes in HIV positive patients. The aim of this study was to document the changing pattern of Candida species prevalence profile in HIV seropositive patients from a tertiary care hospital in North India. One hundred and twenty HIV seropositive subjects were recruited for Candida microbial screening. Clinical specimens including blood, oral swabs, expectorated or induced sputum/bronchoalveolar lavage specimens, and urine were collected depending on the patient’s symptoms. A total of 128 Candida isolates were obtained from 88 cases and 7 different Candida species were identified. C. albicans (50% was the most common species isolated followed by C. glabrata (17% and C. dubliniensis (12.5%. Other species isolated were C. parapsilosis (7.8%, C. krusei, C. tropicalis (4.6% each, and C. kefyr (3%. Strong clinical suspicion along with optimal sampling of an accurate diagnosis of Candida species involved would go a long way in decreasing the morbidity associated with non-albicans Candida species.

Vaginal and anal human papillomavirus infection and seropositivity among female sex workers in amsterdam, the Netherlands: prevalence, concordance and risk factors

NARCIS (Netherlands)

Marra, E.; Kroone, N.; Freriks, E.; van Dam, C. L.; Alberts, C. J.; Hogewoning, A. A.; Bruisten, S.; van Dijk, A.; Kroone, M. M.; Waterboer, T.; Schim van der Loeff, M. F.

2017-01-01

We studied prevalence, risk factors and concordance of vaginal and anal HPV infection and L1 seropositivity among female sex workers (FSW) in Amsterdam. In 2016, FSW aged ≥18 years having a sexually transmitted infections (STI) consultation were invited to participate. Participation entailed taking

Associação entre sorologia para Neospora caninum e taxa de prenhez em vacas receptoras de embriões Association between seropositivity for Neospora caninum and pregnancy rate in bovine receipts submitted to embryo transfer technology

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G.F. Paz

2007-10-01

Full Text Available The association between seropositivity for Neospora caninum and pregnancy rate in cows belonging to a surrogate herd submitted to embryo transfer technology was determined. The serological status was evaluated in 275 heifers, aging from 14 to 20-month-old. For N. caninum serology analysis of a monoclonal competitive ELISA test Kit was used, and 81 animals (29.5% showed seropositive. Thus, two groups were randomly formed selecting 33 seropositive heifers and other 33 seronegative animals out of the remaining 194 animals. Seronegative animals were followed up by serological analysis until the end of the trial in order to identify persistently infected individuals. The pregnancy rate was 72.7% in the group of N. caninum-positive sera, and, 81.8% in the seronegative group.No significant difference was observed between groups according to Chi-square test. No association between N. caninum seropositivity and pregnancy rates in surrogate heifers was found.

Fatores associados à soropositividade do teste ML Flow em pacientes e contatos de pacientes com hanseníase menores de 18 anos Factors associated with ML Flow test seropositivity in leprosy patients and household contacts under the age of 18

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Maria Aparecida Alves Ferreira

2008-01-01

Full Text Available Estudo transversal em menores de 18 anos, sendo 115 casos novos de hanseníase e 1.011 contatos intradomiciliares. Determinaram-se as proporções da soropositividade do ML Flow e fatores associados ao teste positivo. Observou-se soropositividade em 21,7% dos pacientes e 19,7% dos contatos. Nos pacientes, a regressão logística indicou associação com baciloscopia positiva e número de lesões cutâneas maior que cinco. A análise por árvore de decisão mostrou associação com baciloscopia, classificação de Madri, número de nervos acometidos e idade. Nos contatos, as duas análises indicaram as mesmas associações: classificação do caso-índice, idade e tipo de serviço de saúde. As variáveis que explicaram melhor a soropositividade, em menores de 18 anos, são aquelas associadas à maior carga bacilar. Assim, o teste ML Flow poderia ser utilizado também na infância para ajudar na correta classificação dos pacientes para tratamento e na identificação dos contatos com maior risco de desenvolver hanseníase.This article presents the results of a cross-sectional study involving 115 newly-diagnosed leprosy patients and 1,011 household contacts, all under the age of 18. Seropositivity ratios and factors associated with a positive ML Flow were determined. The test was positive in 21.7% of patients and in 19.7% of contacts. Among patients, logistic regression indicated the association of seropositivity with positive slit skin smear and having more than five skin lesions. The tree method analysis indicated associations with skin smear, Madrid classification, number of nerves affected and age. In the contact group, index case classification, age and type of health service were associated with seropositivity in both analyses. The variables that best explained seropositivity are those associated with higher bacterial load. Therefore, the ML Flow test could be used in children to aid correct classification of patients for treatment and to

Impact of PGL-I seropositivity on the protective effect of BCG vaccination among leprosy contacts: a cohort study.

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Nádia C Düppre

Full Text Available BACKGROUND: Contacts of leprosy patients are at increased risk of developing leprosy and need to be targeted for early diagnosis. Seropositivity to the phenolic glycolipid I (PGL-I antigen of Mycobacterium leprae has been used to identify contacts who have an increased risk of developing leprosy. In the present study, we studied the effect of seropositivity in patient contacts, on the risk of developing leprosy, stratified by Bacille Calmette Guerin (BCG vaccination after index case diagnosis. METHODOLOGY/PRINCIPAL FINDINGS: Leprosy contacts were examined as part of the surveillance programme of the Oswaldo Cruz Institute Leprosy Outpatient Clinic in Rio de Janeiro. Demographic, social, epidemiological and clinical data were collected. The presence of IgM antibodies to PGL-I in sera and BCG vaccination status at the time of index case diagnosis were evaluated in 2,135 contacts. During follow-up, 60 (2.8%; 60/2,135 leprosy cases were diagnosed: 41 among the 1,793 PGL-I-negative contacts and 19 among the 342 PGL-I-positive contacts. Among PGL-I-positive contacts, BCG vaccination after index case diagnosis increased the adjusted rate of developing clinical manifestations of leprosy (Adjusted Rate Ratio (aRR = 4.1; 95% CI: 1.8-8.2 compared with the PGL-I-positive unvaccinated contacts (aRR = 3.2; 95% CI: 1.2-8.1. The incidence density was highest during the first year of follow-up for the PGL-I-positive vaccinated contacts. However, all of those contacts developed PB leprosy, whereas most MB cases (4/6 occurred in PGL-I-positive unvaccinated contacts. CONCLUSION: Contact examination combined with PGL-I testing and BCG vaccination remain important strategies for leprosy control. The finding that rates of leprosy cases were highest among seropositive contacts justifies targeting this specific group for close monitoring. Furthermore, it is recommended that PGL-I-positive contacts and contacts with a high familial bacteriological index

Impact of PGL-I Seropositivity on the Protective Effect of BCG Vaccination among Leprosy Contacts: A Cohort Study

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Düppre, Nádia C.; Camacho, Luiz Antonio B.; Sales, Anna M.; Illarramendi, Ximena; Nery, José Augusto C.; Sampaio, Elizabeth P.; Sarno, Euzenir N.; Bührer-Sékula, Samira

2012-01-01

Background Contacts of leprosy patients are at increased risk of developing leprosy and need to be targeted for early diagnosis. Seropositivity to the phenolic glycolipid I (PGL-I) antigen of Mycobacterium leprae has been used to identify contacts who have an increased risk of developing leprosy. In the present study, we studied the effect of seropositivity in patient contacts, on the risk of developing leprosy, stratified by Bacille Calmette Guerin (BCG) vaccination after index case diagnosis. Methodology/Principal Findings Leprosy contacts were examined as part of the surveillance programme of the Oswaldo Cruz Institute Leprosy Outpatient Clinic in Rio de Janeiro. Demographic, social, epidemiological and clinical data were collected. The presence of IgM antibodies to PGL-I in sera and BCG vaccination status at the time of index case diagnosis were evaluated in 2,135 contacts. During follow-up, 60 (2.8%; 60/2,135) leprosy cases were diagnosed: 41 among the 1,793 PGL-I-negative contacts and 19 among the 342 PGL-I-positive contacts. Among PGL-I-positive contacts, BCG vaccination after index case diagnosis increased the adjusted rate of developing clinical manifestations of leprosy (Adjusted Rate Ratio (aRR) = 4.1; 95% CI: 1.8–8.2) compared with the PGL-I-positive unvaccinated contacts (aRR = 3.2; 95% CI: 1.2–8.1). The incidence density was highest during the first year of follow-up for the PGL-I-positive vaccinated contacts. However, all of those contacts developed PB leprosy, whereas most MB cases (4/6) occurred in PGL-I-positive unvaccinated contacts. Conclusion Contact examination combined with PGL-I testing and BCG vaccination remain important strategies for leprosy control. The finding that rates of leprosy cases were highest among seropositive contacts justifies targeting this specific group for close monitoring. Furthermore, it is recommended that PGL-I-positive contacts and contacts with a high familial bacteriological index, regardless of

Frequencies of CCR5-D32, CCR2-64I and SDF1-3’A mutations in Human Immunodeficiency Virus (HIV seropositive subjects and seronegative individuals from the state of Pará in Brazilian Amazonia

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Fernanda Andreza de Pinho Lott Carvalhaes

2005-12-01

Full Text Available The distribution of genetic polymorphisms of chemokine receptors CCR5-delta32, CCR2-64I and chemokine (SDF1-3’A mutations were studied in 110 Human Immunodeficiency Virus type 1 (HIV-1 seropositive individuals (seropositive group and 139 seronegative individuals (seronegative group from the population of the northern Brazilian city of Belém which is the capital of the state of Pará in the Brazilian Amazon. The CCR5-delta32 mutation was found in the two groups at similar frequencies, i.e. 2.2% for the seronegative group and 2.7% for the seropositive group. The frequencies of the SDF1-3’A mutation were 21.0% for the seronegative group and 15.4% for the seropositive group, and the CCR2-64I allele was found at frequencies of 12.5% for the seronegative group and 5.4% for the seropositive group. Genotype distributions were consistent with Hardy-Weinberg expectations in both groups, suggesting that none of the three mutations has a detectable selective effect. Difference in the allelic and genotypic frequencies was statistically significant for the CCR2 locus, the frequency in the seronegative group being twice that found in the seropositive group. This finding may indicate a protective effect of the CCR2-64I mutation in relation to HIV transmission. However, considering that the CCR2-64I mutation has been more strongly associated with a decreased risk for progression for AIDS than to the resistance to the HIV infection, this could reflect an aspect of population structure or a Type I error.

Seropositive abdominal and thoracic donor organs are largely underutilized.

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Taylor, R M; Pietroski, R E; Hagan, M; Eisenbrey, A B; Fontana, R J

2010-12-01

The aim of this study was to describe the epidemiology and utilization of anti-hepatitis B core protein(+) and anti-hepatitis C virus(+) organ donor referrals in a large organ procurement organization. Between 1995 and 2006, 3,134 deceased organ donor referrals were tested for anti-HBc and anti-HCV using commercial assays. The prevalence of anti-HCV(+) organ donor referrals significantly increased from 3.4% in 1994-1996 to 8.1% in 2003-2005 (P organ donor referrals remained unchanged at 3%-4% (P = .20). The 112 anti-HBc(+) (3.5%) and 173 anti-HCV(+) (5.5%) organ donor referrals were significantly older and more likely to be noncaucasian than seronegative organ donor referrals (P donor organs were significantly lower compared with seronegative organ donors (P donors over time (21% vs 46%; P = .026), whereas utilization of anti-HCV(+) liver donors remained unchanged over time (5% vs 18%; P = .303). In summary, the proportion of anti-HCV(+) organ donor referrals has significantly increased and the proportion of anti-HBc(+) organ donor referrals has remained stable. Both thoracic and abdominal organs from seropositive donors are largely underutilized. Copyright © 2010 Elsevier Inc. All rights reserved.

Comparison of seropositivity of human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and syphilis among Hospital Cornea Retrieval Programme-Donors versus voluntary cornea donors at a large eye bank in Eastern India.

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Basak, Soham; Basak, Samar K; Biswas, Bani

2017-11-01

To compare the serology profile of donors from Hospital Cornea Retrieval Programme-donors (HCRP-D) and voluntary cornea donors (VC-D) from a large eye bank in Eastern India. This is a retrospective analysis of donor details from January 2011 to December 2016. Donor demographics, cause of death, and serology reports were compiled. Postmortem blood was tested for human immunodeficiency virus 1 and 2 (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis using government-approved kits as per the National Programme for Control of Blindness Standards of Eye Banking. Donors for whom serology was not possible were excluded. A total of 4300 of 4353 donors were included of which 74.3% were hospital donors and 25.7% were voluntary donors. A total of 93 (2.2%) donors with 94 seropositive reports were noted: 79 (84.9%) from HCRP-D and 14 (15.1%) from VC-D which was statistically significantly higher (P = 0.02). Among seropositive reports, HIV, HBV, HCV, and syphilis accounted for 12 (12.8%), 38 (40.4%), 36 (38.3%), and eight (8.5%), respectively. There was no correlation between the cause of death and seropositivity. A statistically significant decreasing trend in seroprevalence among hospital donors was observed over the years (5.3% in 2011 to 1.4% in 2016; P = 0.004). Two (0.47%) of 421 hospital donors with prior negative serology were found to be seropositive. Seropositive rates are significantly higher among hospital donors in spite of medical prescreening compared to nonscreened voluntary donors. Serology should be repeated even when prior reports are available.

Hormonal levels among HIV-1-seropositive women compared with high-risk HIV-seronegative women during the menstrual cycle. Women's Health Study (WHS) 001 and WHS 001a Study Team.

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Cu-Uvin, S; Wright, D J; Anderson, D; Kovacs, A; Watts, D H; Cohn, J; Landay, A; Reichelderfer, P S

2000-10-01

There is a paucity of normative data on hormonal levels among HIV-infected women. Hormonal levels may influence fertility and HIV-related immunological and virological factors. The objective of this study was to determine progesterone and estradiol levels during the menstrual cycle in HIV-seropositive women compared with high-risk seronegative women. The study enrolled 55 HIV-infected and 10 high-risk uninfected women with self-reported regular menstrual cycles (25-30-day cycles). Progesterone and estradiol levels were determined on a weekly basis for 8 weeks. The analysis included evaluations from the first complete menstrual cycle for the 54 HIV-infected and 9 uninfected women who had at least one complete cycle. The median age was 35 years for HIV-infected women and 36 years for uninfected women. The median CD4+ count for HIV-seropositive women was 210 cells/mm3. The median menstrual cycle length was 28 days (range 22-49 days) for HIV-infected women and 25 days (range 24-44 days) for uninfected women. The maximum progesterone level during the luteal phase was normal (>3.0 ng/ml) for 52 (96%) of 54 HIV-seropositive women and 7 (78%) of 9 HIV-seronegative women (p = 0.09, Fisher's exact test). The median maximum progesterone level was 12.2 ng/ml in HIV-seropositive women and 7.2 ng/ml in HIV-seronegative women (p = 0.07, Wilcoxon test). The median maximum estradiol value during the follicular phase was 148 pg/ml for HIV-seropositive women and 111 pg/ml for HIV-seronegative women (p = 0.04, Wilcoxon test). Among HIV-infected women, there were no significant differences in progesterone and estradiol levels by antiretroviral therapy, baseline plasma viral load, or median CD4+ cell count. We conclude that HIV-infected women with self-reported normal menstrual cycles have normal levels of progesterone and estradiol during the menstrual cycle.

Assessing Nutrient Intake and Nutrient Status of HIV Seropositive Patients Attending Clinic at Chulaimbo Sub-District Hospital, Kenya

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Agatha Christine Onyango

2012-01-01

Full Text Available Background. Nutritional status is an important determinant of HIV outcomes. Objective. To assess the nutrient intake and nutrient status of HIV seropositive patients attending an AIDS outpatient clinic, to improve the nutritional management of HIV-infected patients. Design. Prospective cohort study. Setting. Comprehensive care clinic in Chulaimbo Sub-District Hospital, Kenya. Subjects. 497 HIV sero-positive adults attending the clinic. Main Outcome Measures. Evaluation of nutrient intake using 24-hour recall, food frequency checklist, and nutrient status using biochemical assessment indicators (haemoglobin, creatinine, serum glutamate pyruvate (SGPT and mean corpuscular volume (MCV. Results. Among the 497 patients recruited (M : F sex ratio: 1.4, mean age: 39 years ± 10.5 y, Generally there was inadequate nutrient intake reported among the HIV patients, except iron (10.49 ± 3.49 mg. All the biochemical assessment indicators were within normal range except for haemoglobin 11.2 g/dL (11.4 ± 2.60 male and 11.2 ± 4.25 female. Conclusions. Given its high frequency, malnutrition should be prevented, detected, monitored, and treated from the early stages of HIV infection among patients attending AIDS clinics in order to improve survival and quality of life.

Meningitis caused by Rhodotorula mucilaginosa in human immunodeficiency virus seropositive patient

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Baradkar, V. P.; Kumar, S.

2008-01-01

Rhodotorula species may be responsible for systemic infection in immunocompromised patients. Meningitis by Rhodotorula species in human immunodeficiency virus (HIV) infected persons has been reported previously. We report a case of meningitis caused by Rhodotorula mucilaginosa in a 36-year-old HIV seropositive male patient who presented with fever, altered sensorium and features of meningeal irritation i.e. neck rigidity. The Cerebrospinal fluid (CSF) cell counts were high, showing 150 cells/mm3, with 60% lymphocytes and 40% polymorphs, and protein content of 100 mg%; glucose was 60 mg%. The diagnosis was confirmed by culture on Sabouraud's Dextrose agar. The patient was treated successfully with intensive Amphotericin B (1 mg/kg), for two weeks, followed by oral Itraconazole (400 mg daily), for a period of two months. The patient was started on anti retroviral therapy. He did not show any relapse of the symptoms when the last follow up was done six months after the date of discharge. PMID:19893682

Comparison of seropositivity of human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and syphilis among Hospital Cornea Retrieval Programme-Donors versus voluntary cornea donors at a large eye bank in Eastern India

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Soham Basak

2017-01-01

Full Text Available Purpose: To compare the serology profile of donors from Hospital Cornea Retrieval Programme-donors (HCRP-D and voluntary cornea donors (VC-D from a large eye bank in Eastern India. Methods: This is a retrospective analysis of donor details from January 2011 to December 2016. Donor demographics, cause of death, and serology reports were compiled. Postmortem blood was tested for human immunodeficiency virus 1 and 2 (HIV, hepatitis B virus (HBV, hepatitis C virus (HCV, and syphilis using government-approved kits as per the National Programme for Control of Blindness Standards of Eye Banking. Donors for whom serology was not possible were excluded. Results: A total of 4300 of 4353 donors were included of which 74.3% were hospital donors and 25.7% were voluntary donors. A total of 93 (2.2% donors with 94 seropositive reports were noted: 79 (84.9% from HCRP-D and 14 (15.1% from VC-D which was statistically significantly higher (P = 0.02. Among seropositive reports, HIV, HBV, HCV, and syphilis accounted for 12 (12.8%, 38 (40.4%, 36 (38.3%, and eight (8.5%, respectively. There was no correlation between the cause of death and seropositivity. A statistically significant decreasing trend in seroprevalence among hospital donors was observed over the years (5.3% in 2011 to 1.4% in 2016; P = 0.004. Two (0.47% of 421 hospital donors with prior negative serology were found to be seropositive. Conclusion: Seropositive rates are significantly higher among hospital donors in spite of medical prescreening compared to nonscreened voluntary donors. Serology should be repeated even when prior reports are available.

Genome-wide transcriptome analysis of soybean primary root under varying water-deficit conditions.

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Song, Li; Prince, Silvas; Valliyodan, Babu; Joshi, Trupti; Maldonado dos Santos, Joao V; Wang, Jiaojiao; Lin, Li; Wan, Jinrong; Wang, Yongqin; Xu, Dong; Nguyen, Henry T

2016-01-15

Soybean is a major crop that provides an important source of protein and oil to humans and animals, but its production can be dramatically decreased by the occurrence of drought stress. Soybeans can survive drought stress if there is a robust and deep root system at the early vegetative growth stage. However, little is known about the genome-wide molecular mechanisms contributing to soybean root system architecture. This study was performed to gain knowledge on transcriptome changes and related molecular mechanisms contributing to soybean root development under water limited conditions. The soybean Williams 82 genotype was subjected to very mild stress (VMS), mild stress (MS) and severe stress (SS) conditions, as well as recovery from the severe stress after re-watering (SR). In total, 6,609 genes in the roots showed differential expression patterns in response to different water-deficit stress levels. Genes involved in hormone (Auxin/Ethylene), carbohydrate, and cell wall-related metabolism (XTH/lipid/flavonoids/lignin) pathways were differentially regulated in the soybean root system. Several transcription factors (TFs) regulating root growth and responses under varying water-deficit conditions were identified and the expression patterns of six TFs were found to be common across the stress levels. Further analysis on the whole plant level led to the finding of tissue-specific or water-deficit levels specific regulation of transcription factors. Analysis of the over-represented motif of different gene groups revealed several new cis-elements associated with different levels of water deficit. The expression patterns of 18 genes were confirmed byquantitative reverse transcription polymerase chain reaction method and demonstrated the accuracy and effectiveness of RNA-Seq. The primary root specific transcriptome in soybean can enable a better understanding of the root response to water deficit conditions. The genes detected in root tissues that were associated with

Cytomegalovirus disease in lung transplantation: impact of recipient seropositivity and duration of antiviral prophylaxis.

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Hammond, S P; Martin, S T; Roberts, K; Gabardi, S; Fuhlbrigge, A L; Camp, P C; Goldberg, H J; Marty, F M; Baden, L R

2013-04-01

A recent randomized trial demonstrated that 1 year of antiviral prophylaxis for cytomegalovirus (CMV) after lung transplantation is superior to 3 months of treatment for prevention of CMV disease. However, it is uncertain if a shorter duration of prophylaxis might result in a similar rate of CMV disease among select lung transplant (LT) recipients who are at lower risk for CMV disease, based on baseline donor (D) and recipient (R) CMV serologies. We retrospectively assessed incidence, cumulative probability, and predictors of CMV disease and viremia in LT recipients transplanted between July 2004 and December 2009 at our center, where antiviral CMV prophylaxis for 6-12 months is standard. Of 129 LT recipients, 94 were at risk for CMV infection based on donor CMV seropositivity (D+) or recipient seropositivity (R+); 14 developed CMV disease (14.9%): 11 with CMV syndrome, 2 with pneumonitis, and 1 with gastrointestinal disease by the end of follow-up (October 2010); 17 developed asymptomatic CMV viremia (18.1%). The cumulative probability of CMV disease was 17.4% 18 months after transplantation. CMV D+/R- recipients who routinely received 1 year of prophylaxis were more likely to develop CMV disease compared with D+/R+ or D-/R+ recipients, who routinely received 6 months of prophylaxis (12/45 vs. 2/25 vs. 0/24, P = 0.005). Recipients who stopped CMV prophylaxis before 12 months (in D+/R- recipients) and 6 months (in R+ recipients) tended to develop CMV disease more than those who did not (9/39 vs. 3/41, P = 0.06). On a 6-month CMV prophylaxis protocol, few R+ recipients developed CMV disease in this cohort. In contrast, despite a 12-month prophylaxis protocol, D+/R- LT recipients remained at highest risk for CMV disease. © 2012 John Wiley & Sons A/S.

Surface and canopy fuels vary widely in 24-yr old postfire lodgepole pine forests

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Nelson, K. N.; Turner, M.; Romme, W. H.; Tinker, D. B.

2013-12-01

Extreme fire seasons have become common in western North America, and the extent of young postfire forests has grown as fire frequency and annual area burned have increased. These young forests will set the stage for future fires, but an assessment of fuel loads in young forests is lacking. The rate of fuel re-accumulation and fuels variability in postfire forest landscapes is needed to anticipate future fire occurrence and behavior in the American West. We studied fuel characteristics in young lodgepole pine forests that regenerated after the 1988 fires in Yellowstone National Park to address two questions: (1) How do surface fuel characteristics change with time-since-fire? (2) How do canopy and surface fuels vary across the Yellowstone landscape 24 years postfire? During summer 2012, we re-measured surface fuels in 11 plots that were established in 1996 (8 yrs post fire), and we measured surface and canopy fuels in 82 stands (each 0.25 ha) distributed across the Yellowstone post-1988 fire landscape. In the remeasured plots, surface fuel loads generally increased over the last 16 years. One-hr fuels did not change between sample dates, but all other fuel classes (i.e., 10-hr, 100-hr, and 1000-hr) increased by a factor of two or three. Within the sample timeframe, variability of fuel loads within stands decreased significantly. The coefficients of variation decreased for all fuel classes by 23% to 67%. Data from the 82 plots revealed that canopy and surface fuels in 24-year-old stands varied tremendously across the Yellowstone landscape. Live tree densities spanned 0 to 344,067 trees ha-1, producing a mean available canopy fuel load of 7.7 Mg ha-1 and a wide range from 0 to 47 Mg ha-1. Total surface fuel loads averaged 130 Mg ha-1 and ranged from 49 to 229 Mg ha-1, of which 90% was in the 1000-hr fuel class. The mass of fine surface fuels (i.e., litter/duff, 1-hr, 10-hr, and herbaceous fuels) and canopy fuels (i.e., foliage and 1-hr branches) were strongly and

Histomorphometric and immunohistochemical analysis of infectious agents, T-cell subpopulations and inflammatory adhesion molecules in placentas from HIV-seropositive pregnant women

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Cruz Cristina R

2011-10-01

Full Text Available Abstract Background The aim of this study was to compare histomorphometric changes and the results of immunohistochemical tests for VCAM, ICAM-1, CD4 and CD8 in normal placentas from HIV-seropositive pregnant women. Methods Samples of normal placentas were divided into 2 groups: healthy HIV-seronegative pregnant women (control group = C = 60 and HIV-seropositive women (experimental group = E = 57. Conventional histological sections were submitted to morphometric analysis and evaluated in terms of the immunohistochemical expression of ICAM-1, VCAM, CD4 and CD8. Results The villi in group E were smaller than those in group C. The median for the CD8+ T cell count was higher in group E than in group C (p = 0.03. Immunohistochemical expression of ICAM-1 was observed in 57% of the cases in group E, compared with 21% of those in group C (p = 0.001. There was no difference in VCAM expression or CD4+ cell counts between groups and no correlation between the data for antiretroviral therapy and morphometric or immunohistochemical data. Conclusions The morphometric data showed that placentas of HIV-seropositive pregnant women tend to have smaller villi than those of seronegative women. In addition, immunohistochemical testing for infectious agents helped to identify cases that were positive for microorganisms (6/112 that routine pathological examination had failed to detect. The anti-p24 antibody had a limited ability to detect HIV viral protein in this study (2/57. Correlation of immunohistochemical expression of CD8+ T cells and ICAM-1 with the presence of HIV in the placenta revealed that those expressions can act as biomarkers of inflammatory changes. There was no correlation between the data for antiretroviral therapy and morphometric or immunohistochemical data.

Power System Event Ranking Using a New Linear Parameter-Varying Modeling with a Wide Area Measurement System-Based Approach

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Mohammad Bagher Abolhasani Jabali

2017-07-01

Full Text Available Detecting critical power system events for Dynamic Security Assessment (DSA is required for reliability improvement. The approach proposed in this paper investigates the effects of events on dynamic behavior during nonlinear system response while common approaches use steady-state conditions after events. This paper presents some new and enhanced indices for event ranking based on time-domain simulation and polytopic linear parameter-varying (LPV modeling of a power system. In the proposed approach, a polytopic LPV representation is generated via linearization about some points of the nonlinear dynamic behavior of power system using wide-area measurement system (WAMS concepts and then event ranking is done based on the frequency response of the system models on the vertices. Therefore, the nonlinear behaviors of the system in the time of fault occurrence are considered for events ranking. The proposed algorithm is applied to a power system using nonlinear simulation. The comparison of the results especially in different fault conditions shows the advantages of the proposed approach and indices.

Human immunodeficiency virus (HIV) seropositivity and hepatitis B surface antigenemia (HBSAG) among blood donors in Benin city, Edo state, Nigeria.

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Umolu, Patience Idia; Okoror, Lawrence Ehis; Orhue, Philip

2005-03-01

Human Immunodeficiency Virus and Hepatitis B virus are blood borne pathogens that can be transmitted through blood transfusion and could pose a huge problem in areas where mechanisms of ensuring blood safety are suspect. This study became necessary in a population where most of the blood for transfusion is from commercial blood donors. A total of 130 donors comprising 120 commercial donors and 10 voluntary donors were tested for antibodies to human immunodeficiency virus and hepatitis B surface antigen in Benin city using Immunocomb HIV - 1 and 2 Biospot kit and Quimica Clinica Aplicada direct latex agglutination method respectively. Thirteen (10%) samples were HIV seropositive and 7(5.8%) were HBsAg positive. The age bracket 18 - 25years had the highest numbers of donors and also had the highest number of HBsAg positive cases (7.8%) while the age group 29 - 38years had highest number of HIV seropositive cases. High prevalence of HIV antibodies and Hepatitis B surface antigen was found among commercial blood donors. Appropriate and compulsory screening of blood donors using sensitive methods, must be ensured to prevent post transfusion hepatitis and HIV.

Syphilis sero-positivity in recently admitted and long-term psychiatric inpatients: Screening, prevalence and diagnostic profile

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Maria P Henning

2012-12-01

Full Text Available Background. Syphilis research has neglected the prevalence of the disease among psychiatric patients, and traditional syphilis screening has been reported as inadequate. Objectives. (i To assess the syphilis prevalence among psychiatric patients; (ii to compare psychiatric diagnoses of syphilis-infected and -uninfected patients; (iii to assess self-reported high-risk sexual behaviour; (iv to establish syphilis/HIV co-morbidity; and (v to investigate the performance of the rapid plasma reagin (RPR test in syphilis screening, compared with the Treponema pallidum haemagglutination (TPHA test. Methods. Psychiatric inpatients at Weskoppies Hospital, Pretoria, who consented to participate in the study (N=195 were categorised according to gender and length of admission (long-term or recent. Non-treponemal RPR, confirmatory TPHA, HIV-rapid and HIV enzyme-linked immunosorbent assay (ELISA tests were performed. A reactive TPHA test was used to diagnose syphilis. Results. The estimated prevalence of syphilis was 11.7%. There was no significant association between TPHA sero-positivity and primary psychiatric diagnosis or self-reported high-risk sexual behaviour. Significant co-morbidity existed between syphilis and HIV (p=0.012. Compared with the TPHA test, the RPR test performed poorly, identifying only 2/23 patients who had a sero-positive TPHA test (8.7% sensitivity and 100% specificity. Conclusions. The prevalence of syphilis was higher than anticipated, supporting the need for routine testing. The significant co-morbidity and alarming prevalence of HIV and syphilis warrant testing for both conditions in all psychiatric admissions. Current syphilis screening with a single RPR test is inadequate; both RPR and TPHA tests should be performed.

Clinical presentation and aetiologies of acute or complicated headache among HIV-seropositive patients in a Ugandan clinic.

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Katwere, Michael; Kambugu, Andrew; Piloya, Theresa; Wong, Matthew; Hendel-Paterson, Brett; Sande, Merle A; Ronald, Allan; Katabira, Elly; Were, Edward M; Menten, Joris; Colebunders, Robert

2009-09-19

We set out to define the relative prevalence and common presentations of the various aetiologies of headache within an ambulant HIV-seropositive adult population in Kampala, Uganda. We conducted a prospective study of adult HIV-1-seropositive ambulatory patients consecutively presenting with new onset headaches. Patients were classified as focal-febrile, focal-afebrile, non-focal-febrile or non-focal-afebrile, depending on presence or absence of fever and localizing neurological signs. Further management followed along a pre-defined diagnostic algorithm to an endpoint of a diagnosis. We assessed outcomes during four months of follow up. One hundred and eighty patients were enrolled (72% women). Most subjects presented at WHO clinical stages III and IV of HIV disease, with a median Karnofsky performance rating of 70% (IQR 60-80).The most common diagnoses were cryptococcal meningitis (28%, n = 50) and bacterial sinusitis (31%, n = 56). Less frequent diagnoses included cerebral toxoplasmosis (4%, n = 7), and tuberculous meningitis (4%, n = 7). Thirty-two (18%) had other diagnoses (malaria, bacteraemia, etc.). No aetiology could be elucidated in 28 persons (15%). Overall mortality was 13.3% (24 of 180) after four months of follow up. Those without an established headache aetiology had good clinical outcomes, with only one death (4% mortality), and 86% were ambulatory at four months. In an African HIV-infected ambulatory population presenting with new onset headache, aetiology was found in at least 70%. Cryptococcal meningitis and sinusitis accounted for more than half of the cases.

Polymorphism in COX-2 modifies the inverse association between Helicobacter pylori seropositivity and esophageal squamous cell carcinoma risk in Taiwan: a case control study.

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Hu, Huang-Ming; Kuo, Chao-Hung; Lee, Chien-Hung; Wu, I-Chen; Lee, Ka-Wo; Lee, Jang-Ming; Goan, Yih-Gang; Chou, Shah-Hwa; Kao, Ein-Long; Wu, Ming-Tsang; Wu, Deng-Chyang

2009-05-23

Overexpression of Cyclooxygenase-2 (COX-2) was observed in many types of cancers, including esophageal squamous cell carcinoma (ESCC). One functional SNP, COX-2 -1195G/A, has been reported to mediate susceptibility of ESCC in Chinese populations. In our previous study, the presence of Helicobacter pylori (H. pylori) was found to play a protective role in development of ESCC. The interaction of COX-2 and H. pylori in gastric cancer was well investigated. However, literature on their interaction in ESCC risk is scarce. The purpose of this study was to evaluate the association and interaction between COX-2 single nucleotide polymorphism (SNP), H. pylori infection and the risk of developing ESCC. One hundred and eighty patients with ESCC and 194 controls were enrolled in this study. Personal data regarding related risk factors, including alcohol consumption, smoking habits and betel quid chewing, were collected via questionnaire. Genotypes of the COX-2 -1195 polymorphism were determined by PCR-based restriction fragment length polymorphism. H. pylori seropositivity was defined by immunochromatographic screening test. Data was analyzed by chi-squared tests and polytomous logistics regression. In analysis adjusting for the covariates and confounders, H. pylori seropositivity was found to be inversely association with the ESCC development (adjusted OR: 0.5, 95% CI: 0.3 - 0.9). COX-2 -1195 AA homozygous was associated with an increased risk of contracting ESCC in comparison with the non-AA group, especially among patients with H. pylori seronegative (adjusted OR ratio: 2.9, 95% CI: 1.2 - 7.3). The effect was strengthened among patients with lower third ESCC (adjusted OR ratio: 6.9, 95% CI 2.1 - 22.5). Besides, H. pylori seropositivity conveyed a notably inverse effect among patients with COX-2 AA polymorphism (AOR ratio: 0.3, 95% CI: 0.1 - 0.9), and the effect was observed to be enhanced for the lower third ESCC patients (AOR ratio: 0.09, 95% CI: 0.02 - 0.47, p for

An ImmunoSignature test distinguishes Trypanosoma cruzi, hepatitis B, hepatitis C and West Nile virus seropositivity among asymptomatic blood donors.

Directory of Open Access Journals (Sweden)

Michael Rowe

2017-09-01

Full Text Available The complexity of the eukaryotic parasite Trypanosoma (T. cruzi manifests in its highly dynamic genome, multi-host life cycle, progressive morphologies and immune-evasion mechanisms. Accurate determination of infection or Chagas' disease activity and prognosis continues to challenge researchers. We hypothesized that a diagnostic platform with higher ligand complexity than previously employed may hold value.We applied the ImmunoSignature Technology (IST for the detection of T. cruzi-specific antibodies among healthy blood donors. IST is based on capturing the information in an individual's antibody repertoire by exposing their peripheral blood to a library of >100,000 position-addressable, chemically-diverse peptides.Initially, samples from two Chagas cohorts declared positive or negative by bank testing were studied. With the first cohort, library-peptides displaying differential binding signals between T. cruzi sero-states were used to train an algorithm. A classifier was fixed and tested against the training-independent second cohort to determine assay performance. Next, samples from a mixed cohort of donors declared positive for Chagas, hepatitis B, hepatitis C or West Nile virus were assayed on the same library. Signals were used to train a single algorithm that distinguished all four disease states. As a binary test, the accuracy of predicting T. cruzi seropositivity by IST was similar, perhaps modestly reduced, relative to conventional ELISAs. However, the results indicate that information beyond determination of seropositivity may have been captured. These include the identification of cohort subclasses, the simultaneous detection and discerning of other diseases, and the discovery of putative new antigens.The central outcome of this study established IST as a reliable approach for specific determination of T. cruzi seropositivity versus disease-free individuals or those with other diseases. Its potential contribution for monitoring and

Helicobacter pylori seropositivity's association with markers of iron, 1-carbon metabolism, and antioxidant status among US adults: a structural equations modeling approach.

Directory of Open Access Journals (Sweden)

May A Beydoun

Full Text Available We tested a model in which Helicobacter pylori seropositivity (Hps predicted iron status, which in turn acted as a predictor for markers of 1-C metabolism that were then allowed to predict antioxidant status.National Health and Nutrition Examination Surveys (NHANES 1999-2000 cross-sectional data among adults aged 20-85 y were analyzed (n = 3,055. Markers of Hps, iron status (serum ferritin and transferrin saturation (TS; 1-C metabolism (serum folate (FOLserum, B-12, total homocysteine (tHcy, methylmalonic acid (MMA and antioxidant status (vitamins A and E were entered into a structural equations model (SEM.Predictors of Hps included older age, lower education and income, racial/ethnic groups (lowest among Non-Hispanic Whites, and lifetime cigarette smoking. SEM modeling indicated that Hps had a direct inverse relationship with iron status (combining serum ferritin and TS which in turn was positively related to 1-C metabolites (higher serum folate, B-12 or lower tHcy/MMA that were positively associated with antioxidant status (combining serum vitamins A and E. Another pathway that was found bypassed 1-C metabolites (Hps → Iron_st → Antiox. The sum of all indirect effects from Hps combining both pathways and the other indirect pathways in the model (Hps → Iron_st → OneCarbon; Hps →OneCarbon →Antiox was estimated at β = -0.006±0.003, p<0.05.In sum, of the total effect of H. pylori seropositivity on antioxidant status, two significant indirect pathways through Iron status and 1-Carbon metabolites were found. Randomized controlled trials should be conducted to uncover the concomitant causal effect of H. pylori eradication on improving iron status, folate, B-12 and antioxidant status among H. pylori seropositive individuals.

Visualizing time-varying harmonics using filter banks

NARCIS (Netherlands)

Duque, C.A.; Da Silveira, P.M.; Ribeiro, P.F.

2011-01-01

Although it is well known that Fourier analysis is in reality only accurately applicable to steady state waveforms, it is a widely used tool to study and monitor time-varying signals, such as are commonplace in electrical power systems. The disadvantages of Fourier analysis, such as frequency

Characteristics of HIV-2 and HIV-1/HIV-2 Dually Seropositive Adults in West Africa Presenting for Care and Antiretroviral Therapy: The IeDEA-West Africa HIV-2 Cohort Study.

Science.gov (United States)

Ekouevi, Didier K; Balestre, Eric; Coffie, Patrick A; Minta, Daouda; Messou, Eugene; Sawadogo, Adrien; Minga, Albert; Sow, Papa Salif; Bissagnene, Emmanuel; Eholie, Serge P; Gottlieb, Geoffrey S; Dabis, François; Zannou, Djimon Marcel; Ahouada, Carin; Akakpo, Jocelyn; Ahomadegbé, Christelle; Bashi, Jules; Gougounon-Houéto, Alice; Azon-Kouanou, Angèle; Houngbé, Fabien; Koumakpaï, Sikiratou; Alihonou, Florence; d'Almeida, Marcelline; Hodonou, Irvine; Hounhoui, Ghislaine; Sagbo, Gracien; Tossa-Bagnan, Leïla; Adjide, Herman; Drabo, Joseph; Bognounou, René; Dienderé, Arnaud; Traore, Eliezer; Zoungrana, Lassane; Zerbo, Béatrice; Sawadogo, Adrien Bruno; Zoungrana, Jacques; Héma, Arsène; Soré, Ibrahim; Bado, Guillaume; Tapsoba, Achille; Yé, Diarra; Kouéta, Fla; Ouedraogo, Sylvie; Ouédraogo, Rasmata; Hiembo, William; Gansonré, Mady; Messou, Eugène; Gnokoro, Joachim Charles; Koné, Mamadou; Kouakou, Guillaume Martial; Bosse, Clarisse Amani; Brou, Kouakou; Assi, Achi Isidore; Chenal, Henri; Hawerlander, Denise; Soppi, Franck; Minga, Albert; Abo, Yao; Bomisso, Germain; Eholié, Serge Paul; Amego, Mensah Deborah Noelly; Andavi, Viviane; Diallo, Zelica; Ello, Frédéric; Tanon, Aristophane Koffi; Koule, Serge Olivier; Anzan, Koffi Charles; Guehi, Calixte; Aka, Edmond Addi; Issouf, Koffi Ladji; Kouakou, Jean-Claude; N'gbeche, Marie-Sylvie; Touré, Pety; Avit-Edi, Divine; Kouakou, Kouadio; Moh, Magloire; Yao, Valérie Andoblé; Folquet, Madeleine Amorissani; Dainguy, Marie-Evelyne; Kouakou, Cyrille; Méa-Assande, Véronique Tanoh; Oka-Berete, Gladys; Zobo, Nathalie; Acquah, Patrick; Kokora, Marie-Berthe; Eboua, Tanoh François; Timité-Konan, Marguerite; Ahoussou, Lucrèce Diecket; Assouan, Julie Kebé; Sami, Mabéa Flora; Kouadio, Clémence; Renner, Lorna; Goka, Bamenla; Welbeck, Jennifer; Sackey, Adziri; Owiafe, Seth Ntiri; Wejse, Christian; Silva, Zacarias José Da; Paulo, Joao; Rodrigues, Amabelia; da Silva, David; Medina, Candida; Oliviera-Souto, Ines; Ostergaard, Lars; Laursen, Alex; Sodemann, Morten; Aaby, Peter; Fomsgaard, Anders; Erikstrup, Christian; Eugen-Olsen, Jesper; Maïga, Moussa Y; Diakité, Fatoumata Fofana; Kalle, Abdoulaye; Katile, Drissa; Traore, Hamar Alassane; Minta, Daouda; Cissé, Tidiani; Dembelé, Mamadou; Doumbia, Mohammed; Fomba, Mahamadou; Kaya, Assétou Soukho; Traoré, Abdoulaye M; Traoré, Hamady; Toure, Amadou Abathina; Dicko, Fatoumata; Sylla, Mariam; Berthé, Alima; Traoré, Hadizatou Coulibaly; Koïta, Anta; Koné, Niaboula; N'diaye, Clémentine; Coulibaly, Safiatou Touré; Traoré, Mamadou; Traoré, Naïchata; Charurat, Man; Ajayi, Samuel; Dapiap, Stephen; Otu; Igbinoba, Festus; Benson, Okwara; Adebamowo, Clément; James, Jesse; Obaseki; Osakede, Philip; Olasode, John; Sow, Papa Salif; Diop, Bernard; Manga, Noël Magloire; Tine, Judicael Malick; Signate Sy, Haby; Ba, Abou; Diagne, Aida; Dior, Hélène; Faye, Malick; Gueye, Ramatoulaye Diagne; Mbaye, Aminata Diack; Patassi, Akessiwe; Kotosso, Awèrou; Kariyare, Benjamin Goilibe; Gbadamassi, Gafarou; Komi, Agbo; Mensah-Zukong, Kankoé Edem; Pakpame, Pinuwe; Lawson-Evi, Annette Koko; Atakouma, Yawo; Takassi, Elom; Djeha, Améyo; Ephoévi-Gah, Ayoko; Djibril, Sherifa El-Hadj; Dabis, François; Bissagnene, Emmanuel; Arrivé, Elise; Coffie, Patrick; Ekouevi, Didier; Jaquet, Antoine; Leroy, Valériane; Lewden, Charlotte; Sasco, Annie; Azani, Jean-Claude; Allou, Gérard; Balestre, Eric; Bohossou, Franck; Karcher, Sophie; Gonsan, Jules Mahan; Carrou, Jérôme Le; Lenaud, Séverin; Nchot, Célestin; Malateste, Karen; Yao, Amon Roseamonde; Siloué, Bertine; Clouet, Gwenaelle; Djetouan, Hugues; Doring, Alexandra; Kouakou, Adrienne; Rabourdin, Elodie; Rivenc, Jean; Anglaret, Xavier; Ba, Boubacar; Essanin, Jean Bosco; Ciaranello, Andrea; Datté, Sébastien; Desmonde, Sophie; Diby, Jean-Serge Elvis; Gottlieb, Geoffrey S; Horo, Apollinaire Gninlgninrin; Kangah, Serge N'zoré; Malvy, Denis; Meless, David; Mounkaila-Harouna, Aida; Ndondoki, Camille; Shiboski, Caroline; Thiébaut, Rodolphe; Pac-Ci; Abidjan

2013-01-01

HIV-2 is endemic in West Africa. There is a lack of evidence-based guidelines on the diagnosis, management and antiretroviral therapy (ART) for HIV-2 or HIV-1/HIV-2 dual infections. Because of these issues, we designed a West African collaborative cohort for HIV-2 infection within the framework of the International epidemiological Databases to Evaluate AIDS (IeDEA). We collected data on all HIV-2 and HIV-1/HIV-2 dually seropositive patients (both ARV-naive and starting ART) and followed-up in clinical centres in the IeDEA-WA network including a total of 13 clinics in five countries: Benin, Burkina-Faso Côte d'Ivoire, Mali, and Senegal, in the West Africa region. Data was merged for 1,754 patients (56% female), including 1,021 HIV-2 infected patients (551 on ART) and 733 dually seropositive for both HIV-1 and HIV 2 (463 on ART). At ART initiation, the median age of HIV-2 patients was 45.3 years, IQR: (38.3-51.7) and 42.4 years, IQR (37.0-47.3) for dually seropositive patients (p = 0.048). Overall, 16.7% of HIV-2 patients on ART had an advanced clinical stage (WHO IV or CDC-C). The median CD4 count at the ART initiation is 166 cells/mm(3), IQR (83-247) among HIV-2 infected patients and 146 cells/mm(3), IQR (55-249) among dually seropositive patients. Overall, in ART-treated patients, the CD4 count increased 126 cells/mm(3) after 24 months on ART for HIV-2 patients and 169 cells/mm(3) for dually seropositive patients. Of 551 HIV-2 patients on ART, 5.8% died and 10.2% were lost to follow-up during the median time on ART of 2.4 years, IQR (0.7-4.3). This large multi-country study of HIV-2 and HIV-1/HIV-2 dual infection in West Africa suggests that routine clinical care is less than optimal and that management and treatment of HIV-2 could be further informed by ongoing studies and randomized clinical trials in this population.

Characteristics of HIV-2 and HIV-1/HIV-2 Dually Seropositive Adults in West Africa Presenting for Care and Antiretroviral Therapy: The IeDEA-West Africa HIV-2 Cohort Study.

Directory of Open Access Journals (Sweden)

Didier K Ekouevi

Full Text Available HIV-2 is endemic in West Africa. There is a lack of evidence-based guidelines on the diagnosis, management and antiretroviral therapy (ART for HIV-2 or HIV-1/HIV-2 dual infections. Because of these issues, we designed a West African collaborative cohort for HIV-2 infection within the framework of the International epidemiological Databases to Evaluate AIDS (IeDEA.We collected data on all HIV-2 and HIV-1/HIV-2 dually seropositive patients (both ARV-naive and starting ART and followed-up in clinical centres in the IeDEA-WA network including a total of 13 clinics in five countries: Benin, Burkina-Faso Côte d'Ivoire, Mali, and Senegal, in the West Africa region.Data was merged for 1,754 patients (56% female, including 1,021 HIV-2 infected patients (551 on ART and 733 dually seropositive for both HIV-1 and HIV 2 (463 on ART. At ART initiation, the median age of HIV-2 patients was 45.3 years, IQR: (38.3-51.7 and 42.4 years, IQR (37.0-47.3 for dually seropositive patients (p = 0.048. Overall, 16.7% of HIV-2 patients on ART had an advanced clinical stage (WHO IV or CDC-C. The median CD4 count at the ART initiation is 166 cells/mm(3, IQR (83-247 among HIV-2 infected patients and 146 cells/mm(3, IQR (55-249 among dually seropositive patients. Overall, in ART-treated patients, the CD4 count increased 126 cells/mm(3 after 24 months on ART for HIV-2 patients and 169 cells/mm(3 for dually seropositive patients. Of 551 HIV-2 patients on ART, 5.8% died and 10.2% were lost to follow-up during the median time on ART of 2.4 years, IQR (0.7-4.3.This large multi-country study of HIV-2 and HIV-1/HIV-2 dual infection in West Africa suggests that routine clinical care is less than optimal and that management and treatment of HIV-2 could be further informed by ongoing studies and randomized clinical trials in this population.

Ultra wide band antennas

CERN Document Server

Begaud, Xavier

2013-01-01

Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recog

[HCV and HBV seropositivity in university students of the State of Nuevo Leòn, Mexico].

Science.gov (United States)

Flores-Castañeda, M S; García-Méndez, B L; Tijerina-Menchaca, R

1996-01-01

Viral hepatitis is a contagious disease. Patients infected with hepatitis B virus (HBV) or hepatitis C virus (HCV), may be either chronically symptomatic or asymptomatic, and suffer cirrhosis and high risk of hepatic carcinoma. Asymptomatic carriers of HBV surface antigen (HBs-Ag) or with anti-HCV antibodies are potentially infectious, and therefore a risk to public health. This work seeks to establish the frequency of seropositivity for HBs-Ag and anti-HCV antibodies in a population of 774 newly accepted students of the Medical School of the Autonomous University of Nuevo Leon, whose average age was 18 years. Second generation ELISA test were used to screen for HBs-Ag and anti-HCV antibodies. HBs-Ag was confirmed by a neutralization test and anti-HCV antibodies were confirmed by a RIBA test. Three sera were positive for HBs-Ag by ELISA and only one serum (0.13% of analyzed samples) was confirmed by the neutralization technique. On the other hand 12 sera were positive for anti-HCV antibodies by ELISA, and eight of these were confirmed by RIBA (1.03% of the analyzed samples). Intensive reactivity bands were found in two sera, and weak reactivity bands were found in six sera. ELISA screening for anti-HCV antibodies showed 0.5% of false positives. This study shows that the frequency of anti-HCV antibodies is 7.95% times higher than that found for HBs-Ag. All seropositive patients were asymptomatic and potentially infective. This demonstrates the need to routinely screen for HBs-Ag and anti-HCV antibodies to establish the prevalence of these diseases in our area.

Comparison of seropositivity of HCV between oral lichen planus and healthy control group in Hamedan province (west of Iran

Directory of Open Access Journals (Sweden)

Ahmad Reza Mobaien

2011-10-01

Full Text Available Background: Lichen planus is an idiopathic inflammatory disease of the skin, nail, hair and mucous membranes. Oral lichen planus (LP is a chronic inflammatory condition that affects the oral mucous membranes with a variety of clinical presentations. Various etiologies include HCV suggested for LP, and the aim of this study was comparison of seropositivity of HCV in LP patients and control group. Methods: All oral LP patients that were referred to dermatology clinic of farshchian hospitalwere entered in the study. Five cc of clot blood was taken from each patient and tested for anti-HCVand when anti-HCV tested positive another 2cc clot bloodwas taken for HCV-Rt-PCR test. The results were analyzed with SPSS 16. Results: This prospective cross-sectional study was conducted on 30 oral lichen planus patients [males 13(43.3% females 17(56.7%] with mean ages of 46±13.7years and 60 healthy individual [males 26(43.3% females 34(56.7%]. There was no oral lichen planus patients who had anti-HCV positive whiles 2 males(3.3% of healthy group had anti-HCV positive which was confirmed by HCV-Rt-PCR. Conclusions: This study showed that there is no correlation between seropositivity of HCV and oral lichen planus in our patients in the west of Iran.

Adenoma detection rate varies greatly during colonoscopy training

NARCIS (Netherlands)

van Doorn, Sascha C.; Klanderman, Robert B.; Hazewinkel, Yark; Fockens, Paul; Dekker, Evelien

2015-01-01

The adenoma detection rate (ADR) is considered the most important quality indicator for colonoscopy and varies widely among colonoscopists. It is unknown whether the ADR of gastroenterology consultants can already be predicted during their colonoscopy training. To evaluate the ADR of fellows in

Polymorphism in COX-2 modifies the inverse association between Helicobacter pylori seropositivity and esophageal squamous cell carcinoma risk in Taiwan: a case control study

Directory of Open Access Journals (Sweden)

Lee Jang-Ming

2009-05-01

Full Text Available Abstract Background Overexpression of Cyclooxygenase-2 (COX-2 was observed in many types of cancers, including esophageal squamous cell carcinoma (ESCC. One functional SNP, COX-2 -1195G/A, has been reported to mediate susceptibility of ESCC in Chinese populations. In our previous study, the presence of Helicobacter pylori (H. pylori was found to play a protective role in development of ESCC. The interaction of COX-2 and H. pylori in gastric cancer was well investigated. However, literature on their interaction in ESCC risk is scarce. The purpose of this study was to evaluate the association and interaction between COX-2 single nucleotide polymorphism (SNP, H. pylori infection and the risk of developing ESCC. Methods One hundred and eighty patients with ESCC and 194 controls were enrolled in this study. Personal data regarding related risk factors, including alcohol consumption, smoking habits and betel quid chewing, were collected via questionnaire. Genotypes of the COX-2 -1195 polymorphism were determined by PCR-based restriction fragment length polymorphism. H. pylori seropositivity was defined by immunochromatographic screening test. Data was analyzed by chi-squared tests and polytomous logistics regression. Results In analysis adjusting for the covariates and confounders, H. pylori seropositivity was found to be inversely association with the ESCC development (adjusted OR: 0.5, 95% CI: 0.3 – 0.9. COX-2 -1195 AA homozygous was associated with an increased risk of contracting ESCC in comparison with the non-AA group, especially among patients with H. pylori seronegative (adjusted OR ratio: 2.9, 95% CI: 1.2 – 7.3. The effect was strengthened among patients with lower third ESCC (adjusted OR ratio: 6.9, 95% CI 2.1 – 22.5. Besides, H. pylori seropositivity conveyed a notably inverse effect among patients with COX-2 AA polymorphism (AOR ratio: 0.3, 95% CI: 0.1 – 0.9, and the effect was observed to be enhanced for the lower third ESCC

Bounds and asymptotics for orthogonal polynomials for varying weights

CERN Document Server

Levin, Eli

2018-01-01

This book establishes bounds and asymptotics under almost minimal conditions on the varying weights, and applies them to universality limits and entropy integrals.  Orthogonal polynomials associated with varying weights play a key role in analyzing random matrices and other topics.  This book will be of use to a wide community of mathematicians, physicists, and statisticians dealing with techniques of potential theory, orthogonal polynomials, approximation theory, as well as random matrices. .

Performance of a solar chimney by varying design parameters

CSIR Research Space (South Africa)

Kumirai, T

2015-08-01

Full Text Available the design of solar chimneys to ensure optimal performance. The purpose of this chapter is to discuss the performance of an example solar chimney by varying the design parameters and examining their effects on the interior ventilation performance... chimney by varying design parameters Tichaona Kumirai, Researcher, Built Environment CSIR Jan-Hendrik Grobler, DPSS CSIR Dr D.C.U. Conradie, Senior researcher, Built Environment CSIR 1 Introduction Trombe walls and solar chimneys are not widely...

The deforestation debate; estimates vary widely over the extent of forest loss

International Nuclear Information System (INIS)

Monastersky, R.

1993-01-01

While tropical forests are vanishing at a disturbing rate, the wide-spread disagreement over deforestation estimates makes it difficult for government officials and scientists to assess the problem. In turn this hampers efforts to gauge the threat of related issues such as habitat destruction and global warming. Creating more confusion is the realization that partly deforested, but not stripped, lands have not been completely taken into account. In addition lands in tropical regions but outside the tropical rain forest are poorly represented. This article uses Brazil as an example of the conflicting estimates. The efforts of the United Nations Food and Agriculture Organization (FAO) to improve its estimates are described. An on-going NASA project to help is also described

Emergence of chikungunya seropositivity in healthy Malaysian adults residing in outbreak-free locations: Chikungunya seroprevalence results from the Malaysian Cohort

Science.gov (United States)

2013-01-01

Background In 1998, Malaysia experienced its first chikungunya virus (CHIKV) outbreak in the suburban areas followed by another two in 2006 (rural areas) and 2008 (urban areas), respectively. Nevertheless, there is still a lack of documented data regarding the magnitude of CHIKV exposure in the Malaysian population. The aim of this study was to determine the extent of chikungunya virus infection in healthy Malaysian adults residing in outbreak-free locations. Methods A cross sectional study of chikungunya (CHIK) seroprevalence was carried out in 2009 amongst The Malaysian Cohort participants living in four states (Kuala Lumpur, Selangor, Pahang and Negeri Sembilan). A total of 945 participants were randomly identified for the study. Potential risk factors for CHIK infection were determined via questionnaires, and IgG antibodies against CHIK were detected by an enzyme-linked immunosorbent assay. Logistic regression identified risk factors associated with CHIK seropositivity, while geographical information system was used for visual and spatial analysis. Results From the 945 serum samples tested, 5.9% was positive for CHIK IgG. Being male, Malay, rural occupancy and Negeri Sembilan residency were identified as univariate predictors for CHIK seropositivity, while multivariate analysis identified being male and rural occupancy as risk factors. Conclusions This study provided evidence that CHIK is slowly emerging in Malaysia. Although the current baseline seroprevalence is low in this country, increasing number of CHIK cases reported to the Malaysia Ministry of Health imply the possibility of CHIK virus becoming endemic in Malaysia. PMID:23379541

Low prevalence of liver-kidney microsomal autoantibodies of type 1 (LKM1) in hepatitis C seropositive subjects on Crete, Greece.

Science.gov (United States)

Drygiannakis, D; Lionis, C; Drygiannakis, I; Pappas, G; Kouroumalis, E

2001-01-01

Hepatitis C is a serious problem on the Greek island of Crete, where a high prevalence of antibodies against hepatitis C (anti-HCV) has recently been reported. This article reports the findings of a study carried out in Crete, which investigated the prevalence of serum autoantibodies in patients with chronic hepatitis C. One hundred and forty two patients (59 men and 83 women), who were found anti-HCV seropositive in two hospitals and two Primary Health Care Centres in Crete, were eligible. Sixty healthy blood donors (46 men, 14 women), which were negative to anti-HCV, were used as the control group. They were randomly selected from those attending Rethymnon Hospital. Autoantibodies were identified using the indirect immunofluorescence (IFL) technique on human epithelial cells from larynx cancer (HEp-2 cells), rat liver-kidney-stomach substrate (CT3) and Chrithidia Luciliae (CL). Serum autoantibodies were detected in 104 HCV patients, yielding an overall prevalence of 73.2%. The most frequent autoantibodies were antinuclear antibodies (ANA), positive in 72 patients (50.7%). Anti-smooth muscle antibodies (ASMA) were detected in 33 patients (23.2%). Only one patient was positive for LKM1 autoantibodies. No autoantibodies were found in 38 patients (26.7%). Autoantibodies were also found in 5 out of the 60 examined healthy blood donors (8.3%). Autoantibodies, mainly ANA and ASMA are very common in HCV seropositive patients from Crete. By contrast LKM1 autoantibodies are exceptionally rare in these patients.

Wide-band segmented power distribution networks

NARCIS (Netherlands)

Tereshchenko, O.V.; Buesink, Frederik Johannes Karel; Leferink, Frank Bernardus Johannes

2013-01-01

This paper discusses a novel design of Power Distribution Network (PDN). By physical structuring of the power plane into repetitive symmetrical and asymmetrical segments of varying size, suppression of the propagation of unwanted noise throughout the PDN over a wide frequency range is achieved.

Toxoplasma gondii seropositivity and co-infection with TORCH pathogens in high-risk patients from Qatar.

Science.gov (United States)

Abu-Madi, Marawan A; Behnke, Jerzy M; Dabritz, Haydee A

2010-04-01

Testing of patients who are deemed to be at high risk for TORCH pathogens, e.g., pregnant women, their fetuses, neonates, and acquired immunodeficiency syndrome (AIDS) patients, is important so that specific treatment can be initiated. This study included 1,857 such patients between 2005 and 2008. Logistic regression was used to evaluate factors associated with Toxoplasma gondii seropositivity. Among 823 women of childbearing age, 35.1% and 5.2% tested positive for T. gondii IgG and IgM, respectively. Three infants nationality, positive cytomegalovirus (CMV) and herpes simplex virus (HSV)-1 serostatus, and negative rubella IgG results. The decreasing prevalence of IgM antibodies between 2005 and 2008 suggested that exposure to T. gondii from food or environmental sources declined over this period in Qatar. Population-based studies of newborns would be helpful to accurately estimate incidence of congenital toxoplasmosis.

Design of 2D time-varying vector fields.

Science.gov (United States)

Chen, Guoning; Kwatra, Vivek; Wei, Li-Yi; Hansen, Charles D; Zhang, Eugene

2012-10-01

Design of time-varying vector fields, i.e., vector fields that can change over time, has a wide variety of important applications in computer graphics. Existing vector field design techniques do not address time-varying vector fields. In this paper, we present a framework for the design of time-varying vector fields, both for planar domains as well as manifold surfaces. Our system supports the creation and modification of various time-varying vector fields with desired spatial and temporal characteristics through several design metaphors, including streamlines, pathlines, singularity paths, and bifurcations. These design metaphors are integrated into an element-based design to generate the time-varying vector fields via a sequence of basis field summations or spatial constrained optimizations at the sampled times. The key-frame design and field deformation are also introduced to support other user design scenarios. Accordingly, a spatial-temporal constrained optimization and the time-varying transformation are employed to generate the desired fields for these two design scenarios, respectively. We apply the time-varying vector fields generated using our design system to a number of important computer graphics applications that require controllable dynamic effects, such as evolving surface appearance, dynamic scene design, steerable crowd movement, and painterly animation. Many of these are difficult or impossible to achieve via prior simulation-based methods. In these applications, the time-varying vector fields have been applied as either orientation fields or advection fields to control the instantaneous appearance or evolving trajectories of the dynamic effects.

Increased occurrence of anti-AQP4 seropositivity and unique HLA Class II associations with neuromyelitis optica (NMO), among Muslim Arabs in Israel.

Science.gov (United States)

Brill, Livnat; Mandel, Micha; Karussis, Dimitrios; Petrou, Panayiota; Miller, Keren; Ben-Hur, Tamir; Karni, Arnon; Paltiel, Ora; Israel, Shoshana; Vaknin-Dembinsky, Adi

2016-04-15

Previous studies have revealed different human leukocyte antigen (HLA) associations in multiple sclerosis (MS) and neuromyelitis optica (NMO), further discriminating these two demyelinating pathological conditions. In worldwide analyses, NMO and opticospinal MS are represented at higher proportions among demyelinating conditions in African, East-Asian and Latin American populations. There are currently no data regarding the prevalence of NMO in Middle East Muslims. The population in Israel is diverse in many ways, and includes subpopulations, based on religion and ethnicity; some exhibit genetic homogeneity. In Israel, the incidence of MS is lower in the Muslim population than the Jewish population and Muslims carry different allele frequency distribution of HLA haplotypes. To evaluate the occurrence of anti-AQP4 seropositivity in the Israeli Muslim population among patients with central nervous system (CNS) demyelinating conditions; and to identify the HLA DR and DQ profiles of Muslim Arab Israeli patients with NMO spectrum of diseases (NMOSD). The prevalence of anti-AQP4 seropositivity was analyzed in 342 samples, obtained from patients with various CNS demyelinating conditions and in a validation set of 310 samples. HLA class II alleles (HLA-DRB1 and DQB1) were examined in DNA samples from 35 Israeli Muslim Arabs NMO patients and compared to available data from 74 Israeli Muslim controls. Our data reveal a significantly increased prevalence of anti-AQP4 seropositivity, indicative of NMOSD, in Muslim Arab Israeli patients with initial diagnosis of a CNS demyelinating syndrome. In this population, there was a positive association with the HLA-DRB1*04:04 and HLA-DRB1*10:01 alleles (p=0.03), and a strong negative association with the HLA-DRB1*07 and HLA-DQB1*02:02 alleles (p=0.003, p=0.002). Our findings indicate a possibly increased prevalence of NMOSD in Muslim Arabs in Israel with distinct (positive and negative) HLA associations. Further studies in patients with

Global Stability of Polytopic Linear Time-Varying Dynamic Systems under Time-Varying Point Delays and Impulsive Controls

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M. de la Sen

2010-01-01

Full Text Available This paper investigates the stability properties of a class of dynamic linear systems possessing several linear time-invariant parameterizations (or configurations which conform a linear time-varying polytopic dynamic system with a finite number of time-varying time-differentiable point delays. The parameterizations may be timevarying and with bounded discontinuities and they can be subject to mixed regular plus impulsive controls within a sequence of time instants of zero measure. The polytopic parameterization for the dynamics associated with each delay is specific, so that (q+1 polytopic parameterizations are considered for a system with q delays being also subject to delay-free dynamics. The considered general dynamic system includes, as particular cases, a wide class of switched linear systems whose individual parameterizations are timeinvariant which are governed by a switching rule. However, the dynamic system under consideration is viewed as much more general since it is time-varying with timevarying delays and the bounded discontinuous changes of active parameterizations are generated by impulsive controls in the dynamics and, at the same time, there is not a prescribed set of candidate potential parameterizations.

Diagnostic value of anti-annexin A5 antibodies in seropositive versus seronegative antiphospholipid syndrome patients

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Gihan Omar

2018-04-01

Full Text Available Background: Current laboratory criteria for antiphospholipid syndrome (APS classification recommend testing positive for antiphospholipid (aPL antibodies. However, there appears to be a subset of patients with classical APS manifestations who test negative. Aim of the work: To analyze the potential clinical usefulness of testing for anti-annexin A5 antibodies in patients with APS and to study the effectiveness of testing for non-criteria aPLs in an attempt to increase the diagnostic yield, particularly in seronegative APS. Patients and methods: 60 APS patients were divided into two groups; 30 seropositive (SP-APS (group I and 30 age and sex matched seronegative (sN-APS testing negative for aPL antibodies. Serum assay for detection of isotypes of anti-annexin A5 antibodies (IgG and IgM were conducted. Results: The mean age of the patients was 32.9 ± 5.8 years, female:male 57:3 and disease duration in SP-APS versus sN-APS (10.17 ± 4.9 years versus 9.6 ± 5.5 years respectively. Secondary APS was present in 16(53.3% patients in group I compared to 3(10% in group II (p < 0.0001. The mean anti-AnxA5 IgG level was 10.7 ± 5.6 U/ml and IgM was 11.2 ± 7.1 U/ml and were comparable between the 2 groups. The obstetric and thrombotic morbidity had no significant differences between SP and sN-APS. The IgG and IgM levels significantly correlated with the pregnancy morbidity, venous and arterial thrombosis events and showed reasonable sensitivities in their prediction (IgG:71.2%,72.8% and 75.8%; IgM: 68%,67.8% and 71.4% respectively and specificities (IgG:75.9%,77.8% and 81.5%; IgM: 70.9%,73.1% and 73.7% respectively. Conclusion: anti-annexinA5 antibodies are promising for detecting obstetric and thrombotic morbidity in both SP- and sN-APS patients. Keywords: Antiphospholipid syndrome, Seropositive APS (SP-APS, Seronegative APS (sN-APS, Anti-annexin A5 antibodies

Design of 2D Time-Varying Vector Fields

KAUST Repository

Chen, Guoning

2012-10-01

Design of time-varying vector fields, i.e., vector fields that can change over time, has a wide variety of important applications in computer graphics. Existing vector field design techniques do not address time-varying vector fields. In this paper, we present a framework for the design of time-varying vector fields, both for planar domains as well as manifold surfaces. Our system supports the creation and modification of various time-varying vector fields with desired spatial and temporal characteristics through several design metaphors, including streamlines, pathlines, singularity paths, and bifurcations. These design metaphors are integrated into an element-based design to generate the time-varying vector fields via a sequence of basis field summations or spatial constrained optimizations at the sampled times. The key-frame design and field deformation are also introduced to support other user design scenarios. Accordingly, a spatial-temporal constrained optimization and the time-varying transformation are employed to generate the desired fields for these two design scenarios, respectively. We apply the time-varying vector fields generated using our design system to a number of important computer graphics applications that require controllable dynamic effects, such as evolving surface appearance, dynamic scene design, steerable crowd movement, and painterly animation. Many of these are difficult or impossible to achieve via prior simulation-based methods. In these applications, the time-varying vector fields have been applied as either orientation fields or advection fields to control the instantaneous appearance or evolving trajectories of the dynamic effects. © 1995-2012 IEEE.

Design of 2D Time-Varying Vector Fields

KAUST Repository

Chen, Guoning; Kwatra, Vivek; Wei, Li-Yi; Hansen, Charles D.; Zhang, Eugene

2012-01-01

Design of time-varying vector fields, i.e., vector fields that can change over time, has a wide variety of important applications in computer graphics. Existing vector field design techniques do not address time-varying vector fields. In this paper, we present a framework for the design of time-varying vector fields, both for planar domains as well as manifold surfaces. Our system supports the creation and modification of various time-varying vector fields with desired spatial and temporal characteristics through several design metaphors, including streamlines, pathlines, singularity paths, and bifurcations. These design metaphors are integrated into an element-based design to generate the time-varying vector fields via a sequence of basis field summations or spatial constrained optimizations at the sampled times. The key-frame design and field deformation are also introduced to support other user design scenarios. Accordingly, a spatial-temporal constrained optimization and the time-varying transformation are employed to generate the desired fields for these two design scenarios, respectively. We apply the time-varying vector fields generated using our design system to a number of important computer graphics applications that require controllable dynamic effects, such as evolving surface appearance, dynamic scene design, steerable crowd movement, and painterly animation. Many of these are difficult or impossible to achieve via prior simulation-based methods. In these applications, the time-varying vector fields have been applied as either orientation fields or advection fields to control the instantaneous appearance or evolving trajectories of the dynamic effects. © 1995-2012 IEEE.

Factors associated with hepatitis C seropositivity in people living with HIV

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Valdete M. Kuehlkamp

2014-01-01

Full Text Available OBJECTIVE: To identify risk factors associated with hepatitis C virus (HCV seropositivity in human immunodeficiency virus (HIV-infected patients. METHODS: A paired case-control study adjusted by age and gender was conducted. It included adults coinfected with HIV and HCV (cases and HIV mono-infected subjects (controls using non-probability sampling. Data were collected through interviews and review of medical records. The chi-square test was used for comparing categorical variables and the Student’s t-test or Wilcoxon (Mann-Whitney U test for continuous variables. Confidence intervals (95% were estimated along with crude and adjusted odds ratios using conditional logistic regression. RESULTS: A total of 165 patients were surveyed, including 55 cases and 110 controls. The mean age was 43.6 ± 8.4 years, ranging from 19 to 64 years; 70.9% were male. Independent risk factors for HIV/HCV coinfection were education (up to eight years of schooling; age at first intercourse < 15 years; having undergone tattooing; blood transfusion; and use of injecting drugs. CONCLUSIONS: Low level of education, early age at first sexual intercourse, tattooing, blood transfusions, and sharing needles and other drug injection equipment were factors that increased the risk of HIV/HCV coinfection. The results from this research can be compared with similar data from other regions to help direct preventive and educational efforts targeting people living with HIV.

Low prevalence of liver-kidney microsomal autoantibodies of type 1 (LKM1 in hepatitis C seropositive subjects on Crete, Greece

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Pappas Georgios

2001-06-01

Full Text Available Abstract Background Hepatitis C is a serious problem on the Greek island of Crete, where a high prevalence of antibodies against hepatitis C (anti-HCV has recently been reported. This article reports the findings of a study carried out in Crete, which investigated the prevalence of serum autoantibodies in patients with chronic hepatitis C. Patients and Methods One hundred and forty two patients (59 men and 83 women, who were found anti-HCV seropositive in two hospitals and two Primary Health Care Centres in Crete, were eligible. Sixty healthy blood donors (46 men, 14 women, which were negative to anti-HCV, were used as the control group. They were randomly selected from those attending Rethymnon Hospital. Autoantibodies were identified using the indirect immunofluorescence (IFL technique on human epithelial cells from larynx cancer (HEp-2 cells, rat liver-kidney-stomach substrate (CT3 and Chrithidia Luciliae (CL. Results Serum autoantibodies were detected in 104 HCV patients, yielding an overall prevalence of 73.2%. The most frequent autoantibodies were antinuclear antibodies (ANA, positive in 72 patients (50.7%. Anti-smooth muscle antibodies (ASMA were detected in 33 patients (23.2%. Only one patient was positive for LKM1 autoantibodies. No autoantibodies were found in 38 patients (26.7%. Autoantibodies were also found in 5 out of the 60 examined healthy blood donors (8.3%. Conclusions Autoantibodies, mainly ANA and ASMA are very common in HCV seropositive patients from Crete. By contrast LKM1 autoantibodies are exceptionally rare in these patients.

Characterizing wild bird contact and seropositivity to highly pathogenic avian influenza A (H5N1) virus in Alaskan residents.

Science.gov (United States)

Reed, Carrie; Bruden, Dana; Byrd, Kathy K; Veguilla, Vic; Bruce, Michael; Hurlburt, Debby; Wang, David; Holiday, Crystal; Hancock, Kathy; Ortiz, Justin R; Klejka, Joe; Katz, Jacqueline M; Uyeki, Timothy M

2014-09-01

Highly pathogenic avian influenza A (HPAI) H5N1 viruses have infected poultry and wild birds on three continents with more than 600 reported human cases (59% mortality) since 2003. Wild aquatic birds are the natural reservoir for avian influenza A viruses, and migratory birds have been documented with HPAI H5N1 virus infection. Since 2005, clade 2.2 HPAI H5N1 viruses have spread from Asia to many countries. We conducted a cross-sectional seroepidemiological survey in Anchorage and western Alaska to identify possible behaviors associated with migratory bird exposure and measure seropositivity to HPAI H5N1. We enrolled rural subsistence bird hunters and their families, urban sport hunters, wildlife biologists, and a comparison group without bird contact. We interviewed participants regarding their exposures to wild birds and collected blood to perform serologic testing for antibodies against a clade 2.2 HPAI H5N1 virus strain. Hunters and wildlife biologists reported exposures to wild migratory birds that may confer risk of infection with avian influenza A viruses, although none of the 916 participants had evidence of seropositivity to HPAI H5N1. We characterized wild bird contact among Alaskans and behaviors that may influence risk of infection with avian influenza A viruses. Such knowledge can inform surveillance and risk communication surrounding HPAI H5N1 and other influenza viruses in a population with exposure to wild birds at a crossroads of intercontinental migratory flyways. © 2014 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Efeitos da condição sorológica sobre as escolhas reprodutivas de mulheres HIV positivas Effects of seropositivity in reproductive choices of women living with HIV/Aids

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Ana Carolina Cunha Sant'Anna

2009-01-01

Full Text Available O estudo investigou a percepção de mulheres vivendo com HIV/Aids quanto aos efeitos da soropositividade sobre suas escolhas reprodutivas. Optou-se pelo delineamento qualitativo com uso de entrevista individual semi-estruturada com trinta mulheres HIV positivas em idade reprodutiva. A maior parte delas (n=18 afirmou que a soropositividade modificou o desejo de ter filhos. As categorias de motivos mais freqüentes foram o receio do risco de transmissão do HIV para o bebê e soropositividade como sinônimo de morte. Os resultados sinalizam a necessidade de que os serviços atuem em consonância com os programas de atenção integral à saúde da mulher e os princípios do Sistema Único de Saúde, acolhendo e respeitando as decisões reprodutivas de mulheres soropositivas.AIDS epidemiological profile indicates a feminine trend particularly among those in the reproductive age. The study investigated the HIV positive women perception of the seropositivity effects on their reproductive choices. It was chosen a qualitative research design with the use of semi-structured individual interviews with thirty HIV positive women in their reproductive age. As the most frequent categories of reasons, most women reported they did not wish to have children, showing the fear of HIV transmission to the baby and seropositivity as a synonym of death. The findings indicate the need for the services in HIV/AIDS to act in line with the programs of comprehensive health care of women and the principles of Brazilian Health System, respecting the reproductive decisions of seropositive women.

CD4:8 ratio >5 is associated with a dominant naive T-cell phenotype and impaired physical functioning in CMV-seropositive very elderly people: results from the BELFRAIL study.

Science.gov (United States)

Adriaensen, Wim; Derhovanessian, Evelyna; Vaes, Bert; Van Pottelbergh, Gijs; Degryse, Jean-Marie; Pawelec, Graham; Hamprecht, Klaus; Theeten, Heidi; Matheï, Catharina

2015-02-01

A subset of older people is at increased risk of hospitalization and dependency. Emerging evidence suggests that immunosenescence reflected by an inverted CD4:8 ratio and cytomegalovirus (CMV) seropositivity plays an important role in the pathophysiology of functional decline. Nevertheless, the relation between CD4:8 ratio and functional outcome has rarely been investigated. Here, CD4:8 ratio and T-cell phenotypes of 235 community-dwelling persons aged ≥81.5 years in the BELFRAIL study and 25 younger persons (mean age 28.5 years) were analyzed using polychromatic flow cytometry. In the elderly persons, 7.2% had an inverted CD4:8 ratio, which was associated with CMV seropositivity, less naive, and more late-differentiated CD4+ and CD8+ T cells. However, 32.8% had a CD4:8 ratio >5, a phenotype associated with a higher proportion of naive T cells and absent in young donors. In CMV seropositives, this subgroup had lower proportions of late-differentiated CD4+ and CD8+ T cells and weaker anti-CMV immunoglobulin G reactivity. This novel naive T-cell-dominated phenotype was counterintuitively associated with a higher proportion of those with impaired physical functioning in the very elderly people infected with CMV. This underscores the notion that in very elderly people, not merely CMV infection but also the state of its accompanying immune dysregulation is of crucial importance with regard to physical impairment. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Analysis of metabolic changes of brain in HIV-1 seropositive patients with proton magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Koltowska, A.; Hendrich, B.; Sokolska, V.; Mis, M.; Lubkowska, K.; Szewczyk, P.; Sasiadek, M.; Furdal, M.; Knysz, B.; Gasiorowski, J.; Gladysz, A.

2010-01-01

Background: Asymptomatic central nervous system involvement may occur in the early stages of the HIV infection. The aim of the study was to evaluate early brain metabolic changes by means of proton MR spectroscopy (H1MRS) in the HIV-1 seropositive patients without neurological deficits or significant abnormalities in the plain MR study. Material/Methods: The H1MRS examinations were performed with the use of a MR GE Signa 1,5 T system. There were 39 subjects examined, aged 21 to 57 years (mean age 35 years) were examined, including 25 patients infected with HIV-1 and 14 healthy volunteers who constituted a control group. The examinations were performed using the Single Voxel Spectroscopy technique with the PRESS sequence, with following parameters: TR=1500 ms, TE=35 ms, number of acquisitions =128, time of acquisition =3 min. 43 sec. Voxels of 8 cm 3 (20 x 20 x 20 mm) in size were located in the following 5 regions: posterior cingulate gyrus, grey matter of the frontal area, left basal ganglia, white matter of the left parietal area and white matter of the frontal area. The NAA/Cr, Cho/Cr, mI/Cr ratios in the defined regions of interest were statistically analyzed. Results: There was a statistically significant decrease (p < 0.05) in the NAA/Cr ratios in the posterior cingulate area and white matter of the left parietal area in HIV-1 seropositive patients, as compared to the control group. Other metabolite ratios in all the above mentioned locations showed no statistically significant differences, as was also the case for NAA/Cr ratios in grey matter of the frontal area, left basal ganglia and white matter of the frontal area. Conclusions: The reduction of NAA/Cr values revealed in H1MRS studies suggests loss of neurons/neuronal activity in the posterior cingulate area and white matter of the left parietal area, in patients with HIV-1 at the stage before clinical manifestations of retroviral infection and structural changes in the plain MR study. This may reflect a

Brucellosis Seropositivity in Animals and Humans in Ethiopia: A Meta-analysis.

Science.gov (United States)

Tadesse, Getachew

2016-10-01

The objectives of this study were to assess the heterogeneities of estimates and to estimate the seroprevalence of brucellosis in animals and humans in Ethiopia. Data from 70 studies covering 75879 animals and 2223 humans were extracted. Rose Bengal Plate Test (RBPT) and Complement Fixation Test (CFT) in series were the most frequently used serological tests. A random effects model was used to calculate pooled prevalence estimates. The overall True Prevalence of brucellosis seropositivity in goats and sheep were estimated at 5.3% (95%CI = 3.5, 7.5) and 2.7% (95%CI = 1.8, 3.4), respectively, and 2.9% for each of camels and cattle. The prevalence was higher in post-pubertal than in pre-pubertal animals (OR = 3.1, 95% CI = 2.6, 3.7) and in the pastoral than in the mixed crop-livestock production system (OR = 2.8, 95%CI = 2.5, 3.2). The incidence rates of brucellosis in humans of pastoral and sedentary system origins were estimated at 160 and 28 per 100 000 person years, respectively. The seroprevalence of brucellosis is higher in goats than in other species. Its occurrence is evocative of its importance in the country in general and in the pastoral system in particular. Public awareness creation could reduce the transmission of Brucella spp. from animals to humans and the potential of livestock vaccination as a means of control of brucellosis needs to be assessed.

Safety and Immunogenicity of a Recombinant Adenovirus Serotype 35-Vectored HIV-1 Vaccine in Adenovirus Serotype 5 Seronegative and Seropositive Individuals.

Science.gov (United States)

Fuchs, Jonathan D; Bart, Pierre-Alexandre; Frahm, Nicole; Morgan, Cecilia; Gilbert, Peter B; Kochar, Nidhi; DeRosa, Stephen C; Tomaras, Georgia D; Wagner, Theresa M; Baden, Lindsey R; Koblin, Beryl A; Rouphael, Nadine G; Kalams, Spyros A; Keefer, Michael C; Goepfert, Paul A; Sobieszczyk, Magdalena E; Mayer, Kenneth H; Swann, Edith; Liao, Hua-Xin; Haynes, Barton F; Graham, Barney S; McElrath, M Juliana

2015-05-01

Recombinant adenovirus serotype 5 (rAd5)-vectored HIV-1 vaccines have not prevented HIV-1 infection or disease and pre-existing Ad5 neutralizing antibodies may limit the clinical utility of Ad5 vectors globally. Using a rare Ad serotype vector, such as Ad35, may circumvent these issues, but there are few data on the safety and immunogenicity of rAd35 directly compared to rAd5 following human vaccination. HVTN 077 randomized 192 healthy, HIV-uninfected participants into one of four HIV-1 vaccine/placebo groups: rAd35/rAd5, DNA/rAd5, and DNA/rAd35 in Ad5-seronegative persons; and DNA/rAd35 in Ad5-seropositive persons. All vaccines encoded the HIV-1 EnvA antigen. Antibody and T-cell responses were measured 4 weeks post boost immunization. All vaccines were generally well tolerated and similarly immunogenic. As compared to rAd5, rAd35 was equally potent in boosting HIV-1-specific humoral and cellular immunity and responses were not significantly attenuated in those with baseline Ad5 seropositivity. Like DNA, rAd35 efficiently primed rAd5 boosting. All vaccine regimens tested elicited cross-clade antibody responses, including Env V1/V2-specific IgG responses. Vaccine antigen delivery by rAd35 is well-tolerated and immunogenic as a prime to rAd5 immunization and as a boost to prior DNA immunization with the homologous insert. Further development of rAd35-vectored prime-boost vaccine regimens is warranted.

Conceptual Modeling of Time-Varying Information

DEFF Research Database (Denmark)

Gregersen, Heidi; Jensen, Christian S.

2004-01-01

A wide range of database applications manage information that varies over time. Many of the underlying database schemas of these were designed using the Entity-Relationship (ER) model. In the research community as well as in industry, it is common knowledge that the temporal aspects of the mini......-world are important, but difficult to capture using the ER model. Several enhancements to the ER model have been proposed in an attempt to support the modeling of temporal aspects of information. Common to the existing temporally extended ER models, few or no specific requirements to the models were given...

Detection of human parvovirus 4 viremia in the follow-up blood samples from seropositive individuals suggests the existence of persistent viral replication or reactivation of latent viral infection.

Science.gov (United States)

Chen, Mao-Yuan; Hung, Chien-Ching; Lee, Kuang-Lun

2015-06-19

The transmission routes for human parvovirus 4 (PARV4) infections in areas with high seroprevalence are not known. In the work described here, persistent PARV4 viral replication was investigated by conducting a longitudinal study. Ten healthcare workers each provided a blood sample at the beginning of the study (first sample) and 12 months later (second sample). The paired samples were tested for PARV4-positivity by immunoblotting analysis and nested polymerase chain reactions. IgG antibodies against PARV4 were detected in six participants, three of whom also had IgM antibodies against PARV4. The immunoblotting results did not vary over time. PARV4 DNA was detected in the first blood sample from one participant who had IgG antibodies against PARV4 and in the second blood samples from 2 participants who had IgG and IgM antibodies against PARV4. Detection of PARV4 DNA in the second blood samples from two seropositive participants suggests the existence of persistent PARV4 replication or reactivation of inactive virus in the tissues. The finding of persistent or intermittent PARV4 replication in individuals with past infections provides an important clue toward unraveling the non-parenteral transmission routes of PARV4 infection in areas where the virus is endemic.

Symptomatic Congenital Cytomegalovirus Infection in Children of Seropositive Women

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Ines Mack

2017-06-01

Full Text Available Cytomegalovirus (CMV is the most frequent congenital virus infection worldwide. The risk of congenital CMV (cCMV transmission is highest in seronegative women who acquire primary CMV infection during pregnancy. A growing body of evidence indicates that secondary CMV infections in pregnant women with preconceptual immunity (either through reactivation of latent virus or re-infection with a new strain of CMV contribute to a much greater proportion of symptomatic cCMV than was previously thought. Here, we describe a case of symptomatic cCMV infection in the newborn of a woman with proven immunity prior to pregnancy. Diagnosis was confirmed by CMV PCR from amniotic fluid and fetal MR imaging. The newborn presented with typical cCMV symptoms including jaundice, hepatosplenomegaly, cholestasis, petechiae, small head circumference, and sensorineural hearing loss, the most common neurologic sequela. CMV was detected in infant blood and urine by PCR, and intravenous ganciclovir was initiated and continued orally for 6 weeks totally. Apart from persisting right-sided deafness, the child exhibited normal neurological development up through the last follow-up at 4.5 years. To date, the most effective strategy to prevent vertical CMV transmission is hygiene counseling for women of childbearing age, which, in our case, and in concordance with recent literature, applies to seronegative, as well as seropositive, women. Once an expecting mother shows seroconversion or signs of an active CMV infection, there are no established procedures to reduce the risk of transmission, or therapeutic options for the fetus with signs of infection. After birth, symptomatic infants can be treated with ganciclovir to inhibit viral replication and improve hearing ability and neurodevelopmental outcome. A comprehensive review of the literature, including our case study, reveals the most current and significant diagnostic and treatment options available. In conclusion, the triad

Human Immunodeficiency Virus Seropositivity in Children Aged Six-Eighty-four Months at Kenyatta National Hospital

International Nuclear Information System (INIS)

Mugo, J.W.; Wafula, D.M.; Ngacha, D.M.; Musia, J.; Plummer, F.M.; Moses, S.; Ndinya-Achola, J.; Mugo, R.W.; Waiyaki, P.

1992-01-01

To determine the prevalence of the HIV sero positivity in general paediatric emergency admissions at Kenyatta National Hospital, 552 children were studied systematically for four months in 1991. A clinical history was taken and physical examination conducted. The HIV status was determined by use of organon Teknika's Vironostika viral lysate assay for initial two screenings and then a Behring's enzygnost and anti HIV synthetic peptide assay as a confirmatory assay. Seventy (12.7%) of all the children studied were HIV positive, the mean age of the HIV -positive children was 17.5 months while that of total study population was 23.5 months. HIV seropositivity was not associated with history or parental injections. No haemophilia patient was recruited during the study period, and of all the 18 sicklers recruited, none was HIV positive despite multiple blood transfusions. The WHO paediatric Aids Case definition criteria had moderately low sensitivity (55.7%), high specificity (85.9%) and low positive predictive value (36.4%). This was in agreement with observations noted in earlier studies in East and Central Africa

Mental Health of HIV-Seropositive Women During Pregnancy and Postpartum Period: A Comprehensive Literature Review

Science.gov (United States)

Dass-Brailsford, Priscilla; Nora, Diana; Talisman, Nicholas

2014-01-01

With growing numbers of HIV-seropositive (HIV+) women of child-bearing age and increased access to effective clinical protocols for preventing mother-to-child transmission (MTCT) of HIV, mental health-related factors have become increasingly relevant due to their potential to affect the women’s quality of life, obstetric outcomes and risk of MTCT. This review synthesizes evidence from 53 peer-reviewed publications examining mental health-related variables in pregnant and postpartum HIV+ women. The presentation of results is organized by the level of socioeconomic resources in the countries where studies were conducted (i.e., high-, middle-, and low-income countries). It is concluded that psychiatric symptoms, particularly depression, and mental health vulnerabilities (e.g., inadequate coping skills) are widespread among pregnant HIV+ women globally and have a potential to affect psychological well-being, quality of life and salient clinical outcomes. The current body of evidence provides rationale for developing and evaluating clinical and structural interventions aimed at improving mental health outcomes and their clinical correlates in pregnant HIV+ women. PMID:24584458

Seropositivity for hepatitis B and C in voluntary blood donors

International Nuclear Information System (INIS)

Shah, S.M.A.; Ali, A.

2010-01-01

After the introduction of blood banks and better storage techniques blood is more widely used in patients for various indications. In Pakistan more than 1.5 million pints of blood are collected each year. Hepatitis B and C virus infections are known to occur in the general population and due to their mode of transmission through blood and blood products, it has made safe blood transfusion difficult and screening of blood absolutely necessary. Objectives of this study were to estimate frequency of Hepatitis B and C in blood donors of local area and recommend measures for safe blood transfusion. Methods: This retrospective cross-sectional study was conduced at the Blood Bank, Department of Pathology, Khyber Teaching Hospital, Peshawar from January 01, 2007 to December 31, 2008. It was carried out on 32,042 voluntary, non-remunerated healthy blood donors. They were screened for Hepatitis B surface antigen (HBsAg) and anti-hepatitis C antibodies (anti-HCV antibodies) by ELISA. The patients' age ranged from 18-52 years. They were all males. Results: Out of 32,042 donors, 632 (1.97%) patients were positive for HBsAg, and 502 (1.57%).were positive for anti-HCV antibodies. Conclusion: Incidence of Hepatitis B and C is varying in different areas. It is recommended that properly screened blood only, using a reliable method like ELISA, be transfused to the patients. (author)

Lyme disease risk in dogs in New Brunswick

OpenAIRE

Bjurman, Natalie K.; Bradet, Gina; Lloyd, Vett K.

2016-01-01

This study assessed the seroprevalence of anti-Borrelia burgdorferi antibodies in New Brunswick dogs. Testing of 699 serum samples from dogs across the province revealed a 6% province-wide seropositivity, more than 6 times higher than that found in 2008. The rapid increase in seropositivity indicates increased Lyme disease risk to both canine and human health.

Estimating System-wide Impacts of Smart Grid Demonstrations

Energy Technology Data Exchange (ETDEWEB)

Schneider, Kevin P.; Lightner, Eric M.; Fuller, Jason C.

2015-03-01

Quantifying the impact of a new technology on a single specific distribution feeder is relatively easy, but it does not provide insight into the complexities and variations of a system-wide deployment. It is the inability to extrapolate system-wide impacts that hinders the deployment of many promising new technologies. This paper presents a method of extrapolating technology impacts, either simulated or from a field demonstration, from a limited number of distribution feeders to a system-wide impact. The size of the system can vary from the service territory of a single utility, to a region, or to an entire country. The paper will include an example analysis using the United States Department of Energy (DOE) funded Smart Grid Investment Grant (SGIG) projects, extrapolating their benefits to a national level.

FGWAS: Functional genome wide association analysis.

Science.gov (United States)

Huang, Chao; Thompson, Paul; Wang, Yalin; Yu, Yang; Zhang, Jingwen; Kong, Dehan; Colen, Rivka R; Knickmeyer, Rebecca C; Zhu, Hongtu

2017-10-01

Functional phenotypes (e.g., subcortical surface representation), which commonly arise in imaging genetic studies, have been used to detect putative genes for complexly inherited neuropsychiatric and neurodegenerative disorders. However, existing statistical methods largely ignore the functional features (e.g., functional smoothness and correlation). The aim of this paper is to develop a functional genome-wide association analysis (FGWAS) framework to efficiently carry out whole-genome analyses of functional phenotypes. FGWAS consists of three components: a multivariate varying coefficient model, a global sure independence screening procedure, and a test procedure. Compared with the standard multivariate regression model, the multivariate varying coefficient model explicitly models the functional features of functional phenotypes through the integration of smooth coefficient functions and functional principal component analysis. Statistically, compared with existing methods for genome-wide association studies (GWAS), FGWAS can substantially boost the detection power for discovering important genetic variants influencing brain structure and function. Simulation studies show that FGWAS outperforms existing GWAS methods for searching sparse signals in an extremely large search space, while controlling for the family-wise error rate. We have successfully applied FGWAS to large-scale analysis of data from the Alzheimer's Disease Neuroimaging Initiative for 708 subjects, 30,000 vertices on the left and right hippocampal surfaces, and 501,584 SNPs. Copyright © 2017 Elsevier Inc. All rights reserved.

Lymph nodes cytology in HIV seropositive cases with haematological alterations

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Neelima Tirumalasetti

2014-01-01

Full Text Available Background & objectives: Lymphadenopathy and haematological alterations are the earliest manifestations with other associated opportunistic infections and malignancies. Hence, there is a need for simple investigations like fine needle aspiration cytology (FNAC for evaluation of HIV lymphadenopathy and a haemogram to interpret the haematological alterations. This study was undertaken to analyze the cytological patterns of lymph node lesions in HIV/AIDS patients, to compare with available clinico-pathological and haematological parameters to segregate lymphadenopathy cases for further evaluation. Methods: In the present study, 129 HIV seropositive patients were included. Lymph node aspirates were stained routinely with hematoxylin and eosin and Ziehl-Neelsen (Z-N stains. Special stains and cultures were done in selected patients. Peripheral smears were taken from all the patients and CD4 counts were recorded. Tuberculous lymphadenitis was further categorized. Acid fast bacilli (AFB grading was done on Z-N positive smears. Each lesion was compared with CD4 counts, WHO clinical staging and haematological picture. Results: Cytological diagnosis in 129 patients included tuberculous (n=54, 41.9%, reactive lymphadenopathy (n=46, 35.6%, suppurative (n=16, 12.4% lymphadenitis, non-Hodgkin′s lymphoma (n=4, 3.1%, and Hodgkin′s lymphoma, secondary deposits, other granulomatous lesions, and cryptoccocal lymphadenitis in one patient each. The predominant cytomorphological pattern in tuberculous lymphadenitis was caseous necrosis + epithelioid granuloma formation (51.85%. Grade 2+ Z-N grading was noted in 62.96 per cent of AFB positive smears. CD4 counts showed a descending pattern with progression of WHO clinical staging. Cytopenia was more common in WHO clinical stage IV disease. Interpretation & conclusions: Lymph node cytology was found to be a useful tool for segregating lymphadenopathy cases for further evaluation and for identification of

Patients double-seropositive for ANCA and anti-GBM antibodies have varied renal survival, frequency of relapse, and outcomes compared to single-seropositive patients.

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McAdoo, Stephen P; Tanna, Anisha; Hrušková, Zdenka; Holm, Lisa; Weiner, Maria; Arulkumaran, Nishkantha; Kang, Amy; Satrapová, Veronika; Levy, Jeremy; Ohlsson, Sophie; Tesar, Vladimir; Segelmark, Mårten; Pusey, Charles D

2017-09-01

Co-presentation with both ANCA and anti-GBM antibodies is thought to be relatively rare. Current studies of such 'double-positive' cases report small numbers and variable outcomes. To study this further we retrospectively analyzed clinical features and long-term outcomes of a large cohort of 568 contemporary patients with ANCA-associated vasculitis, 41 patients with anti-GBM disease, and 37 double-positive patients with ANCA and anti-GBM disease from four European centers. Double-positive patients shared characteristics of ANCA-associated vasculitis (AAV), such as older age distribution and longer symptom duration before diagnosis, and features of anti-GBM disease, such as severe renal disease and high frequency of lung hemorrhage at presentation. Despite having more evidence of chronic injury on renal biopsy compared to patients with anti-GBM disease, double-positive patients had a greater tendency to recover from being dialysis-dependent after treatment and had intermediate long-term renal survival compared to the single-positive patients. However, overall patient survival was similar in all three groups. Predictors of poor patient survival included advanced age, severe renal failure, and lung hemorrhage at presentation. No single-positive anti-GBM patients experienced disease relapse, whereas approximately half of surviving patients with AAV and double-positive patients had recurrent disease during a median follow-up of 4.8 years. Thus, double-positive patients have a truly hybrid disease phenotype, requiring aggressive early treatment for anti-GBM disease, and careful long-term follow-up and consideration for maintenance immunosuppression for AAV. Since double-positivity appears common, further work is required to define the underlying mechanisms of this association and define optimum treatment strategies. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Detection of hydrogen peroxide-producing Lactobacillus species in the vagina: a comparison of culture and quantitative PCR among HIV-1 seropositive women

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Balkus Jennifer E

2012-08-01

Full Text Available Abstract Background The presence of hydrogen peroxide (H2O2 producing Lactobacillus in the vagina may play a role in controlling genital HIV-1 shedding. Sensitive molecular methods improve our ability to characterize the vaginal microbiota; however, they cannot characterize phenotype. We assessed the concordance of H2O2-producing Lactobacillus detected by culture with quantitative PCR (qPCR detection of Lactobacillus species commonly assumed to be H2O2-producers. Methods Samples were collected as part of a prospective cohort study of HIV-1 seropositive US women. Cervicovaginal lavage specimens were tested for L. crispatus and L. jensenii using 16S rRNA gene qPCR assays. Vaginal swabs were cultured for Lactobacillus and tested for H2O2-production. We calculated a kappa statistic to assess concordance between culture and qPCR. Results Culture and qPCR results were available for 376 visits from 57 women. Lactobacilli were detected by culture at 308 (82% visits, of which 233 of 308 (76% produced H2O2. L. crispatus and/or L. jensenii were detected at 215 (57% visits. Concordance between detection of L. crispatus and/or L. jensenii by qPCR and H2O2-producing Lactobacillus by culture was 75% (kappa = 0.45. Conclusions Among HIV-1 seropositive women, there was a moderate level of concordance between H2O2-producing Lactobacillus detected by culture and the presence of L. crispatus and/or L. jensenii by qPCR. However, one-quarter of samples with growth of H2O2-producing lactobacilli did not have L. crispatus or L. jensenii detected by qPCR. This discordance may be due to the presence of other H2O2-producing Lactobacillus species.

Vesicle biomechanics in a time-varying magnetic field.

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Ye, Hui; Curcuru, Austen

2015-01-01

Cells exhibit distortion when exposed to a strong electric field, suggesting that the field imposes control over cellular biomechanics. Closed pure lipid bilayer membranes (vesicles) have been widely used for the experimental and theoretical studies of cellular biomechanics under this electrodeformation. An alternative method used to generate an electric field is by electromagnetic induction with a time-varying magnetic field. References reporting the magnetic control of cellular mechanics have recently emerged. However, theoretical analysis of the cellular mechanics under a time-varying magnetic field is inadequate. We developed an analytical theory to investigate the biomechanics of a modeled vesicle under a time-varying magnetic field. Following previous publications and to simplify the calculation, this model treated the inner and suspending media as lossy dielectrics, the membrane thickness set at zero, and the electric resistance of the membrane assumed to be negligible. This work provided the first analytical solutions for the surface charges, electric field, radial pressure, overall translational forces, and rotational torques introduced on a vesicle by the time-varying magnetic field. Frequency responses of these measures were analyzed, particularly the frequency used clinically by transcranial magnetic stimulation (TMS). The induced surface charges interacted with the electric field to produce a biomechanical impact upon the vesicle. The distribution of the induced surface charges depended on the orientation of the coil and field frequency. The densities of these charges were trivial at low frequency ranges, but significant at high frequency ranges. The direction of the radial force on the vesicle was dependent on the conductivity ratio between the vesicle and the medium. At relatively low frequencies (biomechanics under a time-varying magnetic field. Biological effects of clinical TMS are not likely to occur via alteration of the biomechanics of brain

Clinical Correlates of Diarrhea and Gut Parasites among Human Immunodeficiency Virus Seropositive Patients

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Elvis Bisong

2017-09-01

Full Text Available Cluster differentiation 4 (CD4 count estimation, which is not readily available in most resource poor settings in Nigeria, is an important indexdetermining commencement of antiretroviral therapy (ART. It is imperative for physicians who come in contact with these patients in such settings to recognize other parameters to evaluate these patients. The clinical correlates of diarrhea and gut parasites among human immunodeficiency virus (HIV-seropositive patients attending our special treatment clinic were studied. Three hundred and forty consenting HIV-positive adult subjects were enrolled. Their stool and blood specimens were collected for a period of three months. Stool samples were analyzed for the presence of diarrhea and gut parasites. The patients were clinically evaluated by physical examination for the presence of pallor, dehydration, oral thrush, wasting lymphadenopathy, dermatitis, skin hyperpigmentation, and finger clubbing. Participants with diarrhea represented 14.1% of the population, while 21.5% harbored one or more parasites. In the subjects with diarrhea, 14.6% harbored gut parasites. The presence of diarrhea was associated with a low CD4 count. Clinically, oral thrush, wasting, and rashes were more reliable predictors of low CD4 count levels; whereas, the presence of pallor, dehydration, wasting, and rashes correlated with the presence of diarrhea. HIV patients presenting with pallor, dehydration, wasting, and rashes should be evaluated for the presence of diarrhea. The clinical variables associated with low CD4 count in this study may guide commencing antiretroviral therapy in resource poor settings.

Glycomics meets artificial intelligence - Potential of glycan analysis for identification of seropositive and seronegative rheumatoid arthritis patients revealed.

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Chocholova, Erika; Bertok, Tomas; Jane, Eduard; Lorencova, Lenka; Holazova, Alena; Belicka, Ludmila; Belicky, Stefan; Mislovicova, Danica; Vikartovska, Alica; Imrich, Richard; Kasak, Peter; Tkac, Jan

2018-06-01

In this study, one hundred serum samples from healthy people and patients with rheumatoid arthritis (RA) were analyzed. Standard immunoassays for detection of 10 different RA markers and analysis of glycan markers on antibodies in 10 different assay formats with several lectins were applied for each serum sample. A dataset containing 2000 data points was data mined using artificial neural networks (ANN). We identified key RA markers, which can discriminate between healthy people and seropositive RA patients (serum containing autoantibodies) with accuracy of 83.3%. Combination of RA markers with glycan analysis provided much better discrimination accuracy of 92.5%. Immunoassays completely failed to identify seronegative RA patients (serum not containing autoantibodies), while glycan analysis correctly identified 43.8% of these patients. Further, we revealed other critical parameters for successful glycan analysis such as type of a sample, format of analysis and orientation of captured antibodies for glycan analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

The pharmacokinetics and safety profile of oral ganciclovir in combination with trimethoprim in HIV- and CMV-seropositive patients

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Jung, Donald; AbdelHameed, Magdy H; Hunter, John; Teitelbaum, Philip; Dorr, Albert; Griffy, Kay

1999-01-01

Aims We investigated the pharmacokinetics and safety profile of oral ganciclovir coadministered with trimethoprim in HIV-and CMV-seropositive patients. Methods In an open-label, randomized, 3-way crossover study, 12 adult males received oral ganciclovir 1000 mg every 8h, oral trimethoprim 200 mg once daily, or both drugs concomitantly in a sequence of three 7-day treatment periods. Pharmacokinetic parameters were determined and adverse events recorded for each treatment. Results The presence of trimethoprim significantly decreased CLr (12.9%, P = 0.0068) and increased t1/2 (18.1%, P = 0.0378) of ganciclovir. However, these changes are unlikely to be clinically meaningful. There were no statistically significant changes in trimethoprim pharmacokinetic parameters in the presence of ganciclovir, with the exception of a 12.7% increase in Cmin. Ganciclovir was well tolerated when administered alone or in combination with trimethoprim. Conclusions There was no clinically significant pharmacokinetic interaction between oral ganciclovir and trimethoprim when coadministered. PMID:10215748

Hepatitis C: frequency and risk factors associated with sero-positivity among adults in Larkana city

International Nuclear Information System (INIS)

Shaikh, F.H.; Abro, H.A.; Abbasi, P.A.; Buriro, A.

2009-01-01

Viral hepatitis is a major public health problem. Infection with Hepatitis C virus (HCV) leads to chronicity and there are about 170 million people infected with HCV. Up to 70% of chronically infected individuals develop active liver disease. The Objective of the study was to find out the frequency of Anti-HCV seropositivity and risk factors of Hepatitis C Virus (HCV) transmission in people of Larkana city. The study was conducted at Larkana from April 2006 to April 2007. Camps were established in the main general practitioners' clinics. A questionnaire about knowledge of HCV and risk factors of its transmission was administered to subjects. Descriptive statistics were done by SPSS-10. Total 450 cases were enrolled into this study. They were divided into 3 age groups. Eighty-nine (19.8%) cases were in age group 40 years. There were 353 (78.4%) male and 97 (21.6%) female subjects, out of these 450 cases 30 (6.6%) were positive for Anti-HCV. A number of risk factors of HCV transmission were present in these cases. History of therapeutic injections was present in 72 cases and 35 cases used public barber services. History of therapeutic injections and use of barber services for shave were the most frequent risk factors in our study. (author)

Characteristics of pulmonary tuberculosis in HIV seropositive and seronegative patients in a Northeastern region of Brazil

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Liberato Isabella Ramos de Oliveira

2004-01-01

Full Text Available The aim of this study was to analyse the clinical, epidemiological and bacteriological features present in 60 pulmonary tuberculosis patients who were also infected with human immunodeficiency virus (HIV and to compare these with 120 TB patients who were not infected with HIV. The patients with pulmonary tuberculosis and HIV coinfection were mostly male (p = 0.001, showed a higher frequency of weight loss >10 kilos (p <0.001, had a higher rate of non-reaction result to the tuberculin skin test (p <0.001, a higher frequency of negative sputum smear examination for acid-fast bacilli (p = 0.001 and negative sputum culture for Mycobacterium tuberculosis (p = 0.001. Treatment failure was more common in those who were HIV positive (p <0.000. No higher frequency of resistance to antituberculosis drugs was found to be associated with TB/HIV coinfection (p = 0.407. Association between extrapulmonary and pulmonary tuberculosis was more frequent in those seropositive to HIV than those without HIV virus, 30% and 1.6% respectively. These findings showed a predominance of atypical clinical laboratory features in co-infected patients, and suggest that health care personnel should consider the possibility this diagnosis.

Debating Life on Mars: The Knowledge Integration Environment (KIE) in Varied School Settings.

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Shear, Linda

Technology-enabled learning environments are beginning to come of age. Tools and frameworks are now available that have been shown to improve learning and are being deployed more widely in varied school settings. Teachers are now faced with the formidable challenge of integrating these promising new environments with the everyday context in which…

H1N1 influenza viruses varying widely in hemagglutinin stability transmit efficiently from swine to swine and to ferrets.

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Marion Russier

2017-03-01

Full Text Available A pandemic-capable influenza virus requires a hemagglutinin (HA surface glycoprotein that is immunologically unseen by most people and is capable of supporting replication and transmission in humans. HA stabilization has been linked to 2009 pH1N1 pandemic potential in humans and H5N1 airborne transmissibility in the ferret model. Swine have served as an intermediate host for zoonotic influenza viruses, yet the evolutionary pressure exerted by this host on HA stability was unknown. For over 70 contemporary swine H1 and H3 isolates, we measured HA activation pH to range from pH 5.1 to 5.9 for H1 viruses and pH 5.3 to 5.8 for H3 viruses. Thus, contemporary swine isolates vary widely in HA stability, having values favored by both avian (pH >5.5 and human and ferret (pH ≤5.5 species. Using an early 2009 pandemic H1N1 (pH1N1 virus backbone, we generated three viruses differing by one HA residue that only altered HA stability: WT (pH 5.5, HA1-Y17H (pH 6.0, and HA2-R106K (pH 5.3. All three replicated in pigs and transmitted from pig-to-pig and pig-to-ferret. WT and R106 viruses maintained HA genotype and phenotype after transmission. Y17H (pH 6.0 acquired HA mutations that stabilized the HA protein to pH 5.8 after transmission to pigs and 5.5 after transmission to ferrets. Overall, we found swine support a broad range of HA activation pH for contact transmission and many recent swine H1N1 and H3N2 isolates have stabilized (human-like HA proteins. This constitutes a heightened pandemic risk and underscores the importance of ongoing surveillance and control efforts for swine viruses.

Dietary adaptation of FADS genes in Europe varied across time and geography.

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Ye, Kaixiong; Gao, Feng; Wang, David; Bar-Yosef, Ofer; Keinan, Alon

2017-05-26

Fatty acid desaturase (FADS) genes encode rate-limiting enzymes for the biosynthesis of omega-6 and omega-3 long-chain polyunsaturated fatty acids (LCPUFAs). This biosynthesis is essential for individuals subsisting on LCPUFA-poor diets (for example, plant-based). Positive selection on FADS genes has been reported in multiple populations, but its cause and pattern in Europeans remain unknown. Here we demonstrate, using ancient and modern DNA, that positive selection acted on the same FADS variants both before and after the advent of farming in Europe, but on opposite (that is, alternative) alleles. Recent selection in farmers also varied geographically, with the strongest signal in southern Europe. These varying selection patterns concur with anthropological evidence of varying diets, and with the association of farming-adaptive alleles with higher FADS1 expression and thus enhanced LCPUFA biosynthesis. Genome-wide association studies reveal that farming-adaptive alleles not only increase LCPUFAs, but also affect other lipid levels and protect against several inflammatory diseases.

A Case-Control Study of Risk Factors for Bovine Brucellosis Seropositivity in Peninsular Malaysia

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Anka, Mukhtar Salihu; Hassan, Latiffah; Khairani-Bejo, Siti; Zainal, Mohamed Abidin; Mohamad, Ramlan bin; Salleh, Annas; Adzhar, Azri

2014-01-01

Bovine brucellosis was first reported in Peninsular Malaysia in 1950. A subsequent survey conducted in the country revealed that the disease was widespread. Current knowledge on the potential risk factors for brucellosis occurrence on cattle farms in Malaysia is lacking. Therefore, we conducted a case-control study to identify the potential herd-level risk factors for bovine brucellosis occurrence in four states in the country, namely Kelantan, Pahang, Selangor and Negeri Sembilan. Thirty-five cases and 36 controls of herds were selected where data on farm management, biosecurity, medical history and public health were collected. Multivariable logistic regression identified that Brucella seropositive herds were more likely to; have some interaction with wildlife (OR 8.9, 95% CI = 1.59–50.05); originated from farms where multiple species such as buffalo/others (OR 41.8, 95% CI = 3.94–443.19) and goat/sheep (OR 8.9, 95%Cl = 1.10–71.83) were reared, practice extensive production system (OR 13.6, 95% CI 1.31–140.24) and have had episodes of abortion in the past (OR 51.8, 95% CI = 4.54–590.90) when compared to seronegative herds. Considering the lack of information on the epidemiology of bovine brucellosis in peninsular Malaysia and absence of information on preventing the inception or spread of the disease, this report could contribute to the on-going area-wise national brucellosis eradication program. PMID:25265020

A case-control study of risk factors for bovine brucellosis seropositivity in Peninsular Malaysia.

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Anka, Mukhtar Salihu; Hassan, Latiffah; Khairani-Bejo, Siti; Zainal, Mohamed Abidin; Mohamad, Ramlan Bin; Salleh, Annas; Adzhar, Azri

2014-01-01

Bovine brucellosis was first reported in Peninsular Malaysia in 1950. A subsequent survey conducted in the country revealed that the disease was widespread. Current knowledge on the potential risk factors for brucellosis occurrence on cattle farms in Malaysia is lacking. Therefore, we conducted a case-control study to identify the potential herd-level risk factors for bovine brucellosis occurrence in four states in the country, namely Kelantan, Pahang, Selangor and Negeri Sembilan. Thirty-five cases and 36 controls of herds were selected where data on farm management, biosecurity, medical history and public health were collected. Multivariable logistic regression identified that Brucella seropositive herds were more likely to; have some interaction with wildlife (OR 8.9, 95% CI = 1.59-50.05); originated from farms where multiple species such as buffalo/others (OR 41.8, 95% CI = 3.94-443.19) and goat/sheep (OR 8.9, 95%Cl = 1.10-71.83) were reared, practice extensive production system (OR 13.6, 95% CI 1.31-140.24) and have had episodes of abortion in the past (OR 51.8, 95% CI = 4.54-590.90) when compared to seronegative herds. Considering the lack of information on the epidemiology of bovine brucellosis in peninsular Malaysia and absence of information on preventing the inception or spread of the disease, this report could contribute to the on-going area-wise national brucellosis eradication program.

Evolution of human cytomegalovirus-seronegative donor/-seropositive recipient high-risk combination frequency in allogeneic hematopoietic stem cell transplantations at Institute of Hematology and Blood Transfusion during 1995-2014.

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Nemeckova, S; Sroller, V; Stastna-Markova, M

2016-04-01

Human cytomegalovirus (HCMV) establishes lifelong latent infection that can result in severe life-threatening disease in immunosuppressed patients after hematopoietic stem cell transplantation (HSCT). An HCMV-seropositive transplant recipient who receives a graft from a seronegative donor (R+/D-) is at high risk of recurrent HCMV reactivation. To assess the incidence of R+/D- combination, we retrospectively evaluated HCMV-seronegative donors for 746 allogeneic HSCT treatments carried out at our center during 1995-2014. In our cohort, 20% HCMV-seronegative HSCT recipients, 21% HCMV-seronegative related graft donors, and 52% HCMV-seronegative unrelated graft donors were included. Analyses of the HCMV serostatus of hematopoietic stem cell donors during 2 consecutive calendar periods (1995-2005 and 2006-2014) showed a significant increase in the proportion of seronegative donors (odds ratio [OR] = 1.947). In addition, the number of HSCT treatments using an unrelated donor increased (OR = 2.376). Finally, the use of grafts from countries with a very low HCMV prevalence increased. This increase in HCMV seronegativity in unrelated donors and the increased proportion of unrelated donors were responsible for the increased occurrence of the high-risk combination R+/D- (OR = 1.680). If the reduction in the rate of HCMV-seropositive graft donors continues, an increased frequency of HCMV reactivation events in our transplant recipients can be expected, because of the increasing occurrence of the high-risk R+/D- combination. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Asymptomatic HLA-A*02:01–Restricted Epitopes from Herpes Simplex Virus Glycoprotein B Preferentially Recall Polyfunctional CD8+ T Cells from Seropositive Asymptomatic Individuals and Protect HLA Transgenic Mice against Ocular Herpes

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Dervillez, Xavier; Qureshi, Huma; Chentoufi, Aziz A.; Khan, Arif A.; Kritzer, Elizabeth; Yu, David C.; Diaz, Oscar R.; Gottimukkala, Chetan; Kalantari, Mina; Villacres, Maria C.; Scarfone, Vanessa M.; McKinney, Denise M.; Sidney, John; Sette, Alessandro; Nesburn, Anthony B.; Wechsler, Steven L.; BenMohamed, Lbachir

2014-01-01

Evidence from C57BL/6 mice suggests that CD8+ T cells, specific to the immunodominant HSV-1 glycoprotein B (gB) H-2b–restricted epitope (gB498–505), protect against ocular herpes infection and disease. However, the possible role of CD8+ T cells, specific to HLA-restricted gB epitopes, in protective immunity seen in HSV-1–seropositive asymptomatic (ASYMP) healthy individuals (who have never had clinical herpes) remains to be determined. In this study, we used multiple prediction algorithms to identify 10 potential HLA-A*02:01–restricted CD8+ T cell epitopes from the HSV-1 gB amino acid sequence. Six of these epitopes exhibited high-affinity binding to HLA-A*02:01 molecules. In 10 sequentially studied HLA-A*02:01–positive, HSV-1–seropositive ASYMP individuals, the most frequent, robust, and polyfunctional CD8+ T cell responses, as assessed by a combination of tetramer, IFN-γ-ELISPOT, CFSE proliferation, CD107a/b cytotoxic degranulation, and multiplex cytokine assays, were directed mainly against epitopes gB342–350 and gB561–569. In contrast, in 10 HLA-A*02:01–positive, HSV-1–seropositive symptomatic (SYMP) individuals (with a history of numerous episodes of recurrent clinical herpes disease) frequent, but less robust, CD8+ T cell responses were directed mainly against nonoverlapping epitopes (gB183–191 and gB441–449). ASYMP individuals had a significantly higher proportion of HSV-gB–specific CD8+ T cells expressing CD107a/b degranulation marker and producing effector cytokines IL-2, IFN-γ, and TNF-α than did SYMP individuals. Moreover, immunization of a novel herpes-susceptible HLA-A*02:01 transgenic mouse model with ASYMP epitopes, but not with SYMP epitopes, induced strong CD8+ T cell–dependent protective immunity against ocular herpes infection and disease. These findings should guide the development of a safe and effective T cell–based herpes vaccine. PMID:24101547

Process model for ammonia volatilization from anaerobic swine lagoons incorporating varying wind speeds and biogas bubbling

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Ammonia volatilization from treatment lagoons varies widely with the total ammonia concentration, pH, temperature, suspended solids, atmospheric ammonia concentration above the water surface, and wind speed. Ammonia emissions were estimated with a process-based mechanistic model integrating ammonia ...

The relationship between adenovirus-36 seropositivity, obesity and metabolic profile in Turkish children and adults.

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Karamese, M; Altoparlak, U; Turgut, A; Aydogdu, S; Karamese, S Aksak

2015-12-01

Obesity potentially arising from viral infection is known as 'infectobesity'. The latest reports suggest that adenovirus-36 (Adv36) is related to obesity in adults and children. Our aim was not only to determine the Adv36 seropositivity in both obese and non-obese children and adults, but also to investigate correlations between antibody positivity and serum lipid profiles. Both Adv36 positivity and tumour-necrosis-factor-alpha, leptin and interleukin-6 levels were detected in blood samples collected from 146 children and 130 adults by ELISA. Fasting plasma triglycerides, total cholesterol and low-density lipoprotein levels were also measured. Adv36 positivity was determined to be 27·1% and 6% in obese and non-obese children and 17·5% and 4% in obese and non-obese adults, respectively. There was no difference with regard to total cholesterol, low-density lipoprotein, triglyceride, tumour-necrosis-factor-alpha and interleukin-6 levels (P > 0·05). However, there was a significant difference between groups in terms of leptin levels (P obese children and adults. Our results showed that Adv36 may be an obesity agent for both adults and children, parallel with current literature data. However, the available data on a possible relationship between Adv36 infection and obesity both in children and adults do not completely solve the problem.

Nonlinear systems time-varying parameter estimation: Application to induction motors

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Kenne, Godpromesse [Laboratoire d' Automatique et d' Informatique Appliquee (LAIA), Departement de Genie Electrique, IUT FOTSO Victor, Universite de Dschang, B.P. 134 Bandjoun (Cameroon); Ahmed-Ali, Tarek [Ecole Nationale Superieure des Ingenieurs des Etudes et Techniques d' Armement (ENSIETA), 2 Rue Francois Verny, 29806 Brest Cedex 9 (France); Lamnabhi-Lagarrigue, F. [Laboratoire des Signaux et Systemes (L2S), C.N.R.S-SUPELEC, Universite Paris XI, 3 Rue Joliot Curie, 91192 Gif-sur-Yvette (France); Arzande, Amir [Departement Energie, Ecole Superieure d' Electricite-SUPELEC, 3 Rue Joliot Curie, 91192 Gif-sur-Yvette (France)

2008-11-15

In this paper, an algorithm for time-varying parameter estimation for a large class of nonlinear systems is presented. The proof of the convergence of the estimates to their true values is achieved using Lyapunov theories and does not require that the classical persistent excitation condition be satisfied by the input signal. Since the induction motor (IM) is widely used in several industrial sectors, the algorithm developed is potentially useful for adjusting the controller parameters of variable speed drives. The method proposed is simple and easily implementable in real-time. The application of this approach to on-line estimation of the rotor resistance of IM shows a rapidly converging estimate in spite of measurement noise, discretization effects, parameter uncertainties (e.g. inaccuracies on motor inductance values) and modeling inaccuracies. The robustness analysis for this IM application also revealed that the proposed scheme is insensitive to the stator resistance variations within a wide range. The merits of the proposed algorithm in the case of on-line time-varying rotor resistance estimation are demonstrated via experimental results in various operating conditions of the induction motor. The experimental results obtained demonstrate that the application of the proposed algorithm to update on-line the parameters of an adaptive controller (e.g. IM and synchronous machines adaptive control) can improve the efficiency of the industrial process. The other interesting features of the proposed method include fault detection/estimation and adaptive control of IM and synchronous machines. (author)

Shape and Spatially-Varying Reflectance Estimation from Virtual Exemplars.

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Hui, Zhuo; Sankaranarayanan, Aswin C

2017-10-01

This paper addresses the problem of estimating the shape of objects that exhibit spatially-varying reflectance. We assume that multiple images of the object are obtained under a fixed view-point and varying illumination, i.e., the setting of photometric stereo. At the core of our techniques is the assumption that the BRDF at each pixel lies in the non-negative span of a known BRDF dictionary. This assumption enables a per-pixel surface normal and BRDF estimation framework that is computationally tractable and requires no initialization in spite of the underlying problem being non-convex. Our estimation framework first solves for the surface normal at each pixel using a variant of example-based photometric stereo. We design an efficient multi-scale search strategy for estimating the surface normal and subsequently, refine this estimate using a gradient descent procedure. Given the surface normal estimate, we solve for the spatially-varying BRDF by constraining the BRDF at each pixel to be in the span of the BRDF dictionary; here, we use additional priors to further regularize the solution. A hallmark of our approach is that it does not require iterative optimization techniques nor the need for careful initialization, both of which are endemic to most state-of-the-art techniques. We showcase the performance of our technique on a wide range of simulated and real scenes where we outperform competing methods.

Variability in the measurement of hospital-wide mortality rates.

Science.gov (United States)

Shahian, David M; Wolf, Robert E; Iezzoni, Lisa I; Kirle, Leslie; Normand, Sharon-Lise T

2010-12-23

Several countries use hospital-wide mortality rates to evaluate the quality of hospital care, although the usefulness of this metric has been questioned. Massachusetts policymakers recently requested an assessment of methods to calculate this aggregate mortality metric for use as a measure of hospital quality. The Massachusetts Division of Health Care Finance and Policy provided four vendors with identical information on 2,528,624 discharges from Massachusetts acute care hospitals from October 1, 2004, through September 30, 2007. Vendors applied their risk-adjustment algorithms and provided predicted probabilities of in-hospital death for each discharge and for hospital-level observed and expected mortality rates. We compared the numbers and characteristics of discharges and hospitals included by each of the four methods. We also compared hospitals' standardized mortality ratios and classification of hospitals with mortality rates that were higher or lower than expected, according to each method. The proportions of discharges that were included by each method ranged from 28% to 95%, and the severity of patients' diagnoses varied widely. Because of their discharge-selection criteria, two methods calculated in-hospital mortality rates (4.0% and 5.9%) that were twice the state average (2.1%). Pairwise associations (Pearson correlation coefficients) of discharge-level predicted mortality probabilities ranged from 0.46 to 0.70. Hospital-performance categorizations varied substantially and were sometimes completely discordant. In 2006, a total of 12 of 28 hospitals that had higher-than-expected hospital-wide mortality when classified by one method had lower-than-expected mortality when classified by one or more of the other methods. Four common methods for calculating hospital-wide mortality produced substantially different results. This may have resulted from a lack of standardized national eligibility and exclusion criteria, different statistical methods, or

A relação entre soroprevalência de anticorpos contra o glicolipídeo fenólico-I entre crianças em idade escolar e endemicidade da hanseníase no Brasil The relation between seroprevalence of antibodies against phenolic glycolipid-I among school children and leprosy endemicity in Brazil

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Samira Bührer-Sékula

2008-01-01

Full Text Available Os programas de controle da hanseníase se beneficiariam de um método fácil para estimar prevalência e avaliar o impacto das ações de controle na prevalência da doença. A determinação da soroprevalência de anticorpos contra PGL-I através de estudos com crianças em idade escolar foi sugerida como indicador útil da taxa de prevalência da hanseníase a nível municipal.Para investigar se a soropositividade estaria associada aos coeficientes de detecção da hanseníase e se poderia ser usada como indicador da prevalência em outras áreas, 7.073 crianças em três estados endêmicos de hanseníase no Brasil foram testadas. Resultados mostram uma considerável variação da distribuição de soropositividade nas comunidades, independente do número de casos de hanseníase detectados. A soroprevalência foi significativamente menor nos colégios. Nenhuma diferença na distribuição da soropositividade determinada por ELISA ou dipstick foi observada. Nenhuma correlação entre o coeficiente de detecção da hanseníase e soropositividade pôde ser estabelecida.Leprosy control programs would benefit expressively from an easy method to estimate disease prevalence and to assess the effect of leprosy control measures on disease prevalence. Determination of the seroprevalence of antibodies to PGL-I through school children surveys might be a useful indicator of leprosy prevalence at the district level. To investigate whether seropositivity rates could be related to leprosy detection rates and whether seropositivity could be used as a proximal indicator to predict the leprosy incidence in other areas, 7,073 school children in three different leprosy-endemic states in Brazil were tested. The results show a widely varying distribution of seropositivity in the communities independent of the number of leprosy cases detected. Seroprevalence was significantly lower at private schools. No differences in the patterns of seropositivity between ELISA

Risk of newly detected infections and cervical abnormalities in women seropositive for naturally acquired human papillomavirus type 16/18 antibodies: analysis of the control arm of PATRICIA.

Science.gov (United States)

Castellsagué, Xavier; Naud, Paulo; Chow, Song-Nan; Wheeler, Cosette M; Germar, Maria Julieta V; Lehtinen, Matti; Paavonen, Jorma; Jaisamrarn, Unnop; Garland, Suzanne M; Salmerón, Jorge; Apter, Dan; Kitchener, Henry; Teixeira, Julio C; Skinner, S Rachel; Limson, Genara; Szarewski, Anne; Romanowski, Barbara; Aoki, Fred Y; Schwarz, Tino F; Poppe, Willy A J; Bosch, F Xavier; de Carvalho, Newton S; Peters, Klaus; Tjalma, Wiebren A A; Safaeian, Mahboobeh; Raillard, Alice; Descamps, Dominique; Struyf, Frank; Dubin, Gary; Rosillon, Dominique; Baril, Laurence

2014-08-15

We examined risk of newly detected human papillomavirus (HPV) infection and cervical abnormalities in relation to HPV type 16/18 antibody levels at enrollment in PATRICIA (Papilloma Trial Against Cancer in Young Adults; NCT00122681). Using Poisson regression, we compared risk of newly detected infection and cervical abnormalities associated with HPV-16/18 between seronegative vs seropositive women (15-25 years) in the control arm (DNA negative at baseline for the corresponding HPV type [HPV-16: n = 8193; HPV-18: n = 8463]). High titers of naturally acquired HPV-16 antibodies and/or linear trend for increasing antibody levels were significantly associated with lower risk of incident and persistent infection, atypical squamous cells of undetermined significance or greater (ASCUS+), and cervical intraepithelial neoplasia grades 1/2 or greater (CIN1+, CIN2+). For HPV-18, although seropositivity was associated with lower risk of ASCUS+ and CIN1+, no association between naturally acquired antibodies and infection was demonstrated. Naturally acquired HPV-16 antibody levels of 371 (95% confidence interval [CI], 242-794), 204 (95% CI, 129-480), and 480 (95% CI, 250-5756) EU/mL were associated with 90% reduction of incident infection, 6-month persistent infection, and ASCUS+, respectively. Naturally acquired antibodies to HPV-16, and to a lesser extent HPV-18, are associated with some reduced risk of subsequent infection and cervical abnormalities associated with the same HPV type. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

Models of quality-adjusted life years when health varies over time

DEFF Research Database (Denmark)

Hansen, Kristian Schultz; Østerdal, Lars Peter Raahave

2006-01-01

Qualityadjusted life year (QALY) models are widely used for economic evaluation in the health care sector. In the first part of the paper, we establish an overview of QALY models where health varies over time and provide a theoretical analysis of model identification and parameter estimation from...... time tradeoff (TTO) and standard gamble (SG) scores. We investigate deterministic and probabilistic models and consider five different families of discounting functions in all. The second part of the paper discusses four issues recurrently debated in the literature. This discussion includes questioning...... of these two can be used to disentangle risk aversion from discounting. We find that caution must be taken when drawing conclusions from models with chronic health states to situations where health varies over time. One notable difference is that in the former case, risk aversion may be indistinguishable from...

Seroprevalence of feline leukemia virus and feline immunodeficiency virus infection among cats in Canada.

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Little, Susan; Sears, William; Lachtara, Jessica; Bienzle, Dorothee

2009-06-01

The purposes of this study were to determine the seroprevalence of feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) infection among cats in Canada and to identify risk factors for seropositivity. Signalment, lifestyle factors, and test results for FeLV antigen and FIV antibody were analyzed for 11 144 cats from the 10 Canadian provinces. Seroprevalence for FIV antibody was 4.3% and seroprevalence for FeLV antigen was 3.4%. Fifty-eight cats (0.5%) were seropositive for both viruses. Seroprevalence varied geographically. Factors such as age, gender, health status, and lifestyle were significantly associated with risk of FeLV and FIV seropositivity. The results suggest that cats in Canada are at risk of retrovirus infection and support current recommendations that the retrovirus status of all cats should be known.

Membranous glomerulonephritis in a child asymptomatic for hepatitis B virus. Concomitant seropositivity for HBsAG and anti-HBs.

Science.gov (United States)

Hirsch, H Z; Ainsworth, S K; DeBeukelaer, M; Brissie, R M; Hennigar, G R

1981-04-01

The presence of hepatitis B surface antigen (HBsAg) in association with immunoglobulins and complement components within the glomerular basement membranes of adults having chronic active hepatitis has been well documented. In addition, investigators in Poland have demonstrated HBsAg immune complexes in glomeruli of children who did not have clinical evidence of hepatitis. More recently, a single case of childhood membranous glomerulonephritis in an asymptomatic carrier of hepatitis B virus was cited by observers in Canada. Reported here is the deposition of HBsAg immune complexes in the glomerular basement membranes of a 13-year-old black boy who had membranous glomerulopathy but not clinical evidence of hepatitis. This may be the first reported case in the United States of HbsAg-associated membranous glomerulonephritis in a child asymptomatic for hepatitis B virus, and only the second such case in North America. However, unlike previous studies of childhood glomerulopathy in association with hepatitis B virus, this patient is seropositive for both HBsAg and anti-HBs (antibody for hepatitis B surface antigen). Similar "rare" serologic findings were found for the patient's eldest male sib.

Nonlinear control of linear parameter varying systems with applications to hypersonic vehicles

Science.gov (United States)

Wilcox, Zachary Donald

The focus of this dissertation is to design a controller for linear parameter varying (LPV) systems, apply it specifically to air-breathing hypersonic vehicles, and examine the interplay between control performance and the structural dynamics design. Specifically a Lyapunov-based continuous robust controller is developed that yields exponential tracking of a reference model, despite the presence of bounded, nonvanishing disturbances. The hypersonic vehicle has time varying parameters, specifically temperature profiles, and its dynamics can be reduced to an LPV system with additive disturbances. Since the HSV can be modeled as an LPV system the proposed control design is directly applicable. The control performance is directly examined through simulations. A wide variety of applications exist that can be effectively modeled as LPV systems. In particular, flight systems have historically been modeled as LPV systems and associated control tools have been applied such as gain-scheduling, linear matrix inequalities (LMIs), linear fractional transformations (LFT), and mu-types. However, as the type of flight environments and trajectories become more demanding, the traditional LPV controllers may no longer be sufficient. In particular, hypersonic flight vehicles (HSVs) present an inherently difficult problem because of the nonlinear aerothermoelastic coupling effects in the dynamics. HSV flight conditions produce temperature variations that can alter both the structural dynamics and flight dynamics. Starting with the full nonlinear dynamics, the aerothermoelastic effects are modeled by a temperature dependent, parameter varying state-space representation with added disturbances. The model includes an uncertain parameter varying state matrix, an uncertain parameter varying non-square (column deficient) input matrix, and an additive bounded disturbance. In this dissertation, a robust dynamic controller is formulated for a uncertain and disturbed LPV system. The developed

Perfil dos cães sororreagentes para aglutininas anti-Leptospira interrogans em Belo Horizonte, Minas Gerais, 2001/2002 Serological profile of seropositive dogs to anti-Leptospira interrogans agglutinins in Belo Horizonte, Minas Gerais, Brazil, 2001-2002

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D.F. Magalhães

2007-10-01

Full Text Available The serological profile of seropositive dogs according to anti-Leptospira agglutinins was checked in Belo Horizonte including variables such as race, sex, age and whether the dog had an owner or not. The dogs were captured by the Zoonosis Control Center in nine neighborhoods around the city and were separated in two categories - with owners or captured on the streets. The prevalence of anti-Leptospira agglutinins was evaluated in 3,417 blood samples using the microscopic agglutination test (MAT from September 2001 to September 2002. It was found that 13.1% of the dogs had seropositive results with the most reactive serovars being Canicola (7.0%, Ballum (6.1%, Pyrogenes (3.2% and Icterohaemorrhagiae (2.9%. The prevalence of other serovars was less than 1.0%. Greater prevalence was found in male, crossbred dogs, without owners. There were no significant results due to age in 95% (P=0.808 of the cases. According to the results, more research should be done in order to isolate and classify the serovars in positive dogs, especially Ballum and Pyrogenes, which will suggest their inclusion in the commercial vaccines against leptospira used in dogs in this city.

Reliability of White Matter Microstructural Changes in HIV Infection: Metaanalysis and Confirmation

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O’Connor, Erin E.; Jaillard, Assia; Renard, Felix; Zeffiro, Thomas A.

2017-01-01

Background Diffusion tensor imaging (DTI) has been widely used to measure HIV effects on white matter (WM) microarchitecture. While many have reported reduced fractional anisotropy (FA) and increased mean diffusivity (MD) in HIV, quantitative inconsistencies across studies are large. Purpose To evaluate the consistency across studies of HIV effects on DTI measures and then examine DTI reliability in a longitudinal seropositive cohort. Study Selection The meta-analysis included 16 cross-sectional studies reporting FA and 12 studies reporting MD in the corpus callosum. Data Analysis Random effects meta-analysis was used to estimate study standardized mean differences (smd) and heterogeneity. DTI longitudinal reliability was estimated in seropositives studied before, and three and six months after, beginning treatment. Data Synthesis Meta-analysis revealed lower FA (smd −0.43; psmd 0.44; p0.96. Limitation Many studies pooled participants with varying treatments, ages and disease durations. Conclusion HIV effects on WM microstructure exhibited substantial variations that could result from acquisition, processing or cohort selection differences. When acquisition parameters and processing were carefully controlled, the resulting DTI measures did not show high temporal variation. HIV effects on WM microstructure may be age dependent. The high longitudinal reliability of DTI WM microstructure measures make them promising disease activity markers. PMID:28596189

Domestic sheep show average Coxiella burnetii seropositivity generations after a sheep-associated human Q fever outbreak and lack detectable shedding by placental, vaginal, and fecal routes

Science.gov (United States)

Oliveira, Ryan D.; Mousel, Michelle R.; Pabilonia, Kristy L.; Highland, Margaret A.; Taylor, J. Bret; Knowles, Donald P.

2017-01-01

Coxiella burnetii is a globally distributed zoonotic bacterial pathogen that causes abortions in ruminant livestock. In humans, an influenza-like illness results with the potential for hospitalization, chronic infection, abortion, and fatal endocarditis. Ruminant livestock, particularly small ruminants, are hypothesized to be the primary transmission source to humans. A recent Netherlands outbreak from 2007–2010 traced to dairy goats resulted in over 4,100 human cases with estimated costs of more than 300 million euros. Smaller human Q fever outbreaks of small ruminant origin have occurred in the United States, and characterizing shedding is important to understand the risk of future outbreaks. In this study, we assessed bacterial shedding and seroprevalence in 100 sheep from an Idaho location associated with a 1984 human Q fever outbreak. We observed 5% seropositivity, which was not significantly different from the national average of 2.7% for the U.S. (P>0.05). Furthermore, C. burnetii was not detected by quantitative PCR from placentas, vaginal swabs, or fecal samples. Specifically, a three-target quantitative PCR of placenta identified 0.0% shedding (exact 95% confidence interval: 0.0%-2.9%). While presence of seropositive individuals demonstrates some historical C. burnetii exposure, the placental sample confidence interval suggests 2016 shedding events were rare or absent. The location maintained the flock with little or no depopulation in 1984 and without C. burnetii vaccination during or since 1984. It is not clear how a zero-shedding rate was achieved in these sheep beyond natural immunity, and more work is required to discover and assess possible factors that may contribute towards achieving zero-shedding status. We provide the first U.S. sheep placental C. burnetii shedding update in over 60 years and demonstrate potential for C. burnetii shedding to reach undetectable levels after an outbreak event even in the absence of targeted interventions, such

Domestic sheep show average Coxiella burnetii seropositivity generations after a sheep-associated human Q fever outbreak and lack detectable shedding by placental, vaginal, and fecal routes.

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Ryan D Oliveira

Full Text Available Coxiella burnetii is a globally distributed zoonotic bacterial pathogen that causes abortions in ruminant livestock. In humans, an influenza-like illness results with the potential for hospitalization, chronic infection, abortion, and fatal endocarditis. Ruminant livestock, particularly small ruminants, are hypothesized to be the primary transmission source to humans. A recent Netherlands outbreak from 2007-2010 traced to dairy goats resulted in over 4,100 human cases with estimated costs of more than 300 million euros. Smaller human Q fever outbreaks of small ruminant origin have occurred in the United States, and characterizing shedding is important to understand the risk of future outbreaks. In this study, we assessed bacterial shedding and seroprevalence in 100 sheep from an Idaho location associated with a 1984 human Q fever outbreak. We observed 5% seropositivity, which was not significantly different from the national average of 2.7% for the U.S. (P>0.05. Furthermore, C. burnetii was not detected by quantitative PCR from placentas, vaginal swabs, or fecal samples. Specifically, a three-target quantitative PCR of placenta identified 0.0% shedding (exact 95% confidence interval: 0.0%-2.9%. While presence of seropositive individuals demonstrates some historical C. burnetii exposure, the placental sample confidence interval suggests 2016 shedding events were rare or absent. The location maintained the flock with little or no depopulation in 1984 and without C. burnetii vaccination during or since 1984. It is not clear how a zero-shedding rate was achieved in these sheep beyond natural immunity, and more work is required to discover and assess possible factors that may contribute towards achieving zero-shedding status. We provide the first U.S. sheep placental C. burnetii shedding update in over 60 years and demonstrate potential for C. burnetii shedding to reach undetectable levels after an outbreak event even in the absence of targeted

A Combination of CD28 (rs1980422 and IRF5 (rs10488631 Polymorphisms Is Associated with Seropositivity in Rheumatoid Arthritis: A Case Control Study.

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Lucia Vernerova

Full Text Available The aim of the study was to analyse genetic architecture of RA by utilizing multiparametric statistical methods such as linear discriminant analysis (LDA and redundancy analysis (RDA.A total of 1393 volunteers, 499 patients with RA and 894 healthy controls were included in the study. The presence of shared epitope (SE in HLA-DRB1 and 11 SNPs (PTPN22 C/T (rs2476601, STAT4 G/T (rs7574865, CTLA4 A/G (rs3087243, TRAF1/C5 A/G (rs3761847, IRF5 T/C (rs10488631, TNFAIP3 C/T (rs5029937, AFF3 A/T (rs11676922, PADI4 C/T (rs2240340, CD28 T/C (rs1980422, CSK G/A (rs34933034 and FCGR3A A/C (rs396991, rheumatoid factor (RF, anti-citrullinated protein antibodies (ACPA and clinical status was analysed using the LDA and RDA.HLA-DRB1, PTPN22, STAT4, IRF5 and PADI4 significantly discriminated between RA patients and healthy controls in LDA. The correlation between RA diagnosis and the explanatory variables in the model was 0.328 (Trace = 0.107; F = 13.715; P = 0.0002. The risk variants of IRF5 and CD28 genes were found to be common determinants for seropositivity in RDA, while positivity of RF alone was associated with the CTLA4 risk variant in heterozygous form. The correlation between serologic status and genetic determinants on the 1st ordinal axis was 0.468, and 0.145 on the 2nd one (Trace = 0.179; F = 6.135; P = 0.001. The risk alleles in AFF3 gene together with the presence of ACPA were associated with higher clinical severity of RA.The association among multiple risk variants related to T cell receptor signalling with seropositivity may play an important role in distinct clinical phenotypes of RA. Our study demonstrates that multiparametric analyses represent a powerful tool for investigation of mutual relationships of potential risk factors in complex diseases such as RA.

A Combination of CD28 (rs1980422) and IRF5 (rs10488631) Polymorphisms Is Associated with Seropositivity in Rheumatoid Arthritis: A Case Control Study.

Science.gov (United States)

Vernerova, Lucia; Spoutil, Frantisek; Vlcek, Miroslav; Krskova, Katarina; Penesova, Adela; Meskova, Milada; Marko, Andrea; Raslova, Katarina; Vohnout, Branislav; Rovensky, Jozef; Killinger, Zdenko; Jochmanova, Ivana; Lazurova, Ivica; Steiner, Guenter; Smolen, Josef; Imrich, Richard

2016-01-01

The aim of the study was to analyse genetic architecture of RA by utilizing multiparametric statistical methods such as linear discriminant analysis (LDA) and redundancy analysis (RDA). A total of 1393 volunteers, 499 patients with RA and 894 healthy controls were included in the study. The presence of shared epitope (SE) in HLA-DRB1 and 11 SNPs (PTPN22 C/T (rs2476601), STAT4 G/T (rs7574865), CTLA4 A/G (rs3087243), TRAF1/C5 A/G (rs3761847), IRF5 T/C (rs10488631), TNFAIP3 C/T (rs5029937), AFF3 A/T (rs11676922), PADI4 C/T (rs2240340), CD28 T/C (rs1980422), CSK G/A (rs34933034) and FCGR3A A/C (rs396991), rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPA) and clinical status was analysed using the LDA and RDA. HLA-DRB1, PTPN22, STAT4, IRF5 and PADI4 significantly discriminated between RA patients and healthy controls in LDA. The correlation between RA diagnosis and the explanatory variables in the model was 0.328 (Trace = 0.107; F = 13.715; P = 0.0002). The risk variants of IRF5 and CD28 genes were found to be common determinants for seropositivity in RDA, while positivity of RF alone was associated with the CTLA4 risk variant in heterozygous form. The correlation between serologic status and genetic determinants on the 1st ordinal axis was 0.468, and 0.145 on the 2nd one (Trace = 0.179; F = 6.135; P = 0.001). The risk alleles in AFF3 gene together with the presence of ACPA were associated with higher clinical severity of RA. The association among multiple risk variants related to T cell receptor signalling with seropositivity may play an important role in distinct clinical phenotypes of RA. Our study demonstrates that multiparametric analyses represent a powerful tool for investigation of mutual relationships of potential risk factors in complex diseases such as RA.

Transplantation of a Liver Allograft From a Hepatitis C Virus Seropositive Donor With Previous Sustained Virologic Response to an Uninfected Recipient Suffering Steroid Refractory Acute Graft Rejection With No Evidence of HCV Transmission

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Robert A. Mitchell, MD

2018-03-01

Conclusions. To the best of our knowledge, this is the first reported case of an HCV seropositive liver allograft transplanted into an HCV-negative recipient who subsequently received intense immunosuppression. This case, therefore, is an encouraging and novel step in liver transplantation, and demonstrates that SVR may be closer to a true “cure” of HCV in the donor population and that, even in circumstances of very potent immunosuppression in the recipient, this SVR is sustained.

Preditores de soropositividade para HIV em indivíduos não abusadores de drogas que buscam centros de testagem e aconselhamento de Porto Alegre, Rio Grande do Sul, Brasil Predictors of HIV seropositive status in non-IV drug users at testing and counseling centers in Porto Alegre, Rio Grande do Sul, Brazil

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Flávio Pechansky

2005-02-01

Full Text Available Este estudo descreve comportamentos de risco para HIV, obtidos através de questionário, em 570 indivíduos de Porto Alegre que não usavam drogas regularmente. A idade média foi 30,3, 51,1 % eram homens, e a maioria tinha baixa renda (59,1%. A soropositividade foi de 9,9% (13,1% entre homens e 6,9% entre mulheres, associada a sexo masculino, ter mais de 30 anos e baixa renda. Mulheres reportaram mais sexo desprotegido (86,4% do que homens (74,4% e mais sexo com usuários de droga injetável (11,6% versus 2,1%; homens relataram mais sexo homossexual desprotegido (18,7% versus 1,4% e mais relações com profissionais de sexo (19,0% versus 0,4%. Não houve associação entre uso eventual de drogas e soropositividade. A idade associada à soropositividade confirma achados anteriores, indicando maior exposição a riscos durante a vida. O estudo confirma a pauperização da epidemia, com indivíduos pobres apresentando maior soropositividade. Homens e mulheres apresentaram diferentes comportamentos associados à soropositividade, confirmando a necessidade de prevenção específica e distinta para cada grupo.This study describes HIV-related behaviors recorded through a questionnaire applied to 570 individuals in Porto Alegre, Rio Grande do Sul, Brazil, who were not regular drug users. Mean age was 30.3 years, 51.1 % were male, and most were low-income (59.1%. The HIV seropositive rate was 9.9% (13.1% for males, 6.9% for females, and there was a positive association with male gender, age over 30 years, and low income. Women reported more unprotected sex (86.4% than men (74.4% and more sex involving drugs (11.6% vs. 2.1%; men reported more unprotected homosexual sex (18.7% vs. 1.4% and more sex with sex workers (19.0% vs. 0.4%. There was no association between sporadic drug use and seropositive status. The association between age and seropositive status confirms previous findings, indicating more lifetime risk exposure. The study confirms the so

Leptospira interrogans en una población canina del Gran Buenos Aires: variables asociadas con la seropositividad Leptospira interrogans in a canine population of Greater Buenos Aires: variables associated with seropositivity

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Diana Rubel

1997-08-01

Full Text Available Se determinó la seroprevalencia de leptospirosis en una población canina suburbana con el objeto de analizar la asociación entre distintas variables individuales y ambientales y la seropositividad a leptospirosis. El estudio, de diseño transversal, se llevó a cabo durante julio de 1992 en un barrio del Gran Buenos Aires en el que viven unos 9 500 habitantes y una población canina de unos 2 000 animales. Se estudió una muestra aleatoria de 223 perros, de cada uno de los cuales se obtuvo una muestra de sangre. La ficha epidemiológica del animal se obtuvo por encuesta al ama de casa. Las determinaciones serológicas se realizaron por microaglutinación frente a 10 serotipos de Leptospira interrogans. Se halló seropositividad en 57% de los 223 perros examinados; 82% de los sueros positivos coaglutinaron con dos o más serotipos. Los serotipos detectados con mayor frecuencia fueron canicola y pyrogenes. La seroprevalencia en hembras fue menor que en machos (P We determined the seroprevalence of leptospirosis in a suburban canine population for the purpose of analyzing the association between different individual and environmental variables and seropositivity for leptospirosis. The study, which was cross-sectional, was performed in July 1992 in a neighborhood of Greater Buenos Aires with approximately 9 500 inhabitants and a canine population of around 2 000 animals. We studied a random sample of 223 dogs and obtained a blood sample from each. Each animal’s epidemiologic history was obtained by interviewing the housewife. Serologic measurements were performed by the microagglutination technique with the use of 10 different serotypes of Leptospira interrogans. Of the 223 dogs that were tested, 57% showed seropositivity; 82% of the positive sera coagglutinated with two or more serotypes. The most frequently detected serotypes were canicola and pyrogenes. Seroprevalence in females was less common than in males (P <0,05 and in puppies less than

A Reconfigurable Series Resonant DC-DC Converter for Wide-Input and Wide-Output Voltages

DEFF Research Database (Denmark)

Shen, Yanfeng; Wang, Huai; Qin, Zian

2017-01-01

This paper proposes a dual-bridge based LC series resonant dc-dc converter. The input inverter unit incorporates two bridge structures, i.e., a full-bridge inverter and a half-bridge inverter. For the output rectifier, it can be a full-bridge rectifier or an asymmetric half-bridge rectifier....... Different from the conventional resonant converter, a fixed-frequency PWM control is employed which makes the optimization of magnetic components easier. The primary-side switches can achieve ZVS and the secondary-side diodes turn off with ZCS. In addition, the root-mean-square (RMS) values...... of the transformer currents do not significantly vary with respect to the voltage variation. Therefore, this converter can maintain high efficiency over a wide voltage range. The topology and operating principle are firstly described. Then the dc voltage gain and the RMS current characteristics are detailed. Finally...

Some hematological parameters and the prognostic values of CD4, CD8 and total lymphocyte counts and CD4/CD8 cell count ratio in healthy HIV sero-negative, healthy HIV sero-positive and AIDS subjects in Port Harcourt, Nigeria

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Blessing Didia

2008-12-01

Full Text Available OBJECTIVE: The present study attempts to determine normal values of CD4, CD8, CD4/CD8 ratio, total WBC and differential counts, hematocrit and total lymphocyte count (TLC in healthy HIV sero-negative and sero-positive subjects, and to assess the prognostic significance of these parameters in these subjects as compared to AIDS subjects.METHODS: A total of 300 subjects (147 M, 153 F aged between 17 and 71 years were recruited into the study. Subjects were separated according to sex and divided into three groups: Group A: healthy HIV sero-negative subjects; Group B: healthy HIV sero-positive newly diagnosed ART-naïve subjects; and Group C: AIDS subjects. CD4 and CD8 counts were determined by flow cytometry; hematocrit was determined using Hawksley micro-capillary tubes; total WBC and differential counts were determined manually with the improved Neubauer counting chamber; and TLC was obtained by multiplying the percentage of lymphocytes by the total WBC count.RESULTS: For male subjects, significant differences were found in CD4 count, CD4/CD8 count ratio, hematocrit, total WBC and TLC, whereas for female subjects, significant differences were found only in CD4 and CD4/CD8 count ratio in the three groups of subjects. In both sexes, however, these parameters were found to be highest in healthy HIV sero-negative subjects and lowest in AIDS subjects, with HIV sero-positive subjects having intermediate values. CONCLUSION: The results confirm previous reports that the CD4 count and CD4/CD8 count ratio are fairly reliable indicators of the progression of HIV infection. In addition, the results also apparently suggest that the prognostic value of CD8 count is limited and that of TLC possibly sex-dependent. The results could be of importance in our environment since previous reports have been relatively scarce.

Microsatellites in varied arenas of research

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K S Remya

2010-01-01

Full Text Available Microsatellites known as simple-sequence repeats (SSRs or short-tandem repeats (STRs, represent specific sequences of DNA consisting of tandemly repeated units of one to six nucleotides. The repetitive nature of microsatellites makes them particularly prone to grow or shrink in length and these changes can have both good and bad consequences for the organisms that possess them. They are responsible for various neurological diseases and hence the same cause is now utilized for the early detection of various diseases, such as, Schizophrenia and Bipolar Disorder, Congenital generalized Hypertrichosis, Asthma, and Bronchial Hyperresponsiveness. These agents are widely used for forensic identification and relatedness testing, and are predominant genetic markers in this area of application. The application of microsatellites is an extending web and covers the varied scenarios of science, such as, conservation biology, plant genetics, and population studies. At present, researches are progressing round the globe to extend the use of these genetic repeaters to unmask the hidden genetic secrets behind the creation of the world.

Wide area stability analysis and control of interconnected power systems with HVDC and FACTS devices

Energy Technology Data Exchange (ETDEWEB)

Li, Yong

2012-11-01

In order to damp low-frequency oscillations and improve the overall stability of large-scale interconnected power systems, this book investigates the wide-area stability analysis and control methods from different perspectives. The flexible and fast control capability of high-voltage (FACTS) is investigated in detail to implement a wide-area measurement based damping control. A sequential and global mixed optimization method is proposed to simultaneously optimize local and wide area damping controllers. A wide-area robust coordination method is presented to coordinate multiple wide-area damping controllers (WADC). A delay-dependent robust design method is also proposed to handle time-varying delays commonly existing in wide-area signal communication. A closed-loop hardware experiment is used to validate the damping performance. The research activities of this book include power system stability analysis and control, wide-area damping control as well as HVDC and FACTS technologies.

Semen Bacterial Concentrations and HIV-1 RNA Shedding Among HIV-1-Seropositive Kenyan Men.

Science.gov (United States)

Korhonen, Christine J; Srinivasan, Sujatha; Huang, Dandi; Ko, Daisy L; Sanders, Eduard J; Peshu, Norbert M; Krieger, John N; Muller, Charles H; Coombs, Robert W; Fredricks, David N; Graham, Susan M

2017-03-01

HIV-1 is transmitted through semen from men to their sexual partners. Genital infections can increase HIV-1 RNA shedding in semen, but shedding also occurs in the absence of typical pathogens. We hypothesized that higher bacterial concentrations in semen would be associated with higher HIV-1 RNA levels. We analyzed semen samples from 42 HIV-1-seropositive Kenyan men using quantitative polymerase chain reaction (PCR) to assess bacterial concentrations and real-time PCR to measure HIV-1 RNA levels. Generalized estimation equations were used to evaluate associations between these 2 measures. Broad-range 16S rRNA gene PCR with pyrosequencing was performed on a subset of 13 samples to assess bacterial community composition. Bacteria were detected in 96.6% of 88 samples by quantitative PCR. Semen bacterial concentration and HIV-1 RNA levels were correlated 0.30 (P = 0.01). The association between bacterial concentration and HIV-1 RNA detection was not significant after adjustment for antiretroviral therapy (ART) (adjusted odds ratio: 1.27, 95% CI: 0.84 to 1.91). Factors associated with semen bacterial concentration included insertive anal sex (adjusted beta 0.92, 95% CI: 0.12 to 1.73) and ART use (adjusted beta: -0.77, 95% CI: -1.50 to 0.04). Among 13 samples with pyrosequencing data, Corynebacterium spp., Staphylococcus spp., and Streptococcus spp. were most frequently detected. Most of these HIV-1-infected men had bacteria in their semen. ART use was associated with undetectable semen HIV-1 RNA and lower semen bacterial concentrations, whereas insertive anal sex was associated with higher bacterial concentrations. Additional studies evaluating the relationship between semen bacteria, inflammation, mucosal immunity, and HIV-1 shedding are needed to understand implications for HIV-1 transmission.

Disturbances in the cerebral perfusion of human immune deficiency virus-1 seropositive asymptomatic subjects: A quantitative tomography study of 18 cases

International Nuclear Information System (INIS)

Tran Dinh, Y.R.; Mamo, H.; Cervoni, J.; Caulin, C.; Saimot, A.C.

1990-01-01

Quantitative measurements of cerebral blood flow (CBF) by xenon-133 ( 133 Xe) tomography, together with magnetic resonance imaging (MRI), electroencephalography (EEG), psychometric tests, and laboratory analyses were performed on 18 human immunodeficiency virus 1 (HIV-1) seropositive asymptomatic subjects. Abnormalities of cerebral perfusion were observed in 16 cases (88%). These abnormalities were particularly frequent in the frontal regions (77% of cases). MRI demonstrated leucoencephalopathy in only two cases. EEG showed only induced diffuse abnormalities in two cases. Psychometric tests showed restricted moderate disturbances in 55% of patients. These disturbances mostly concerned those sectors involved in cognitive functions and memorization. These results indicate that quantitative measurements of CBF by 133 Xe-SPECT is capable of detecting abnormalities of cerebral perfusion at a very early stage (Phase II) of HIV-1 infection. These abnormalities are indications of disturbances resulting from unidentified metabolic or vascular lesions. This technique appears to be superior to MRI at this stage of the disease's development. It could provide objective information leading to earlier treatment, and prove useful in evaluating potential antiviral chemotherapy

Wide-angle full-vector beam propagation method based on an alternating direction implicit preconditioner

Science.gov (United States)

Chui, Siu Lit; Lu, Ya Yan

2004-03-01

Wide-angle full-vector beam propagation methods (BPMs) for three-dimensional wave-guiding structures can be derived on the basis of rational approximants of a square root operator or its exponential (i.e., the one-way propagator). While the less accurate BPM based on the slowly varying envelope approximation can be efficiently solved by the alternating direction implicit (ADI) method, the wide-angle variants involve linear systems that are more difficult to handle. We present an efficient solver for these linear systems that is based on a Krylov subspace method with an ADI preconditioner. The resulting wide-angle full-vector BPM is used to simulate the propagation of wave fields in a Y branch and a taper.

Innate immune function in placenta and cord blood of hepatitis C--seropositive mother-infant dyads.

Science.gov (United States)

Hurtado, Christine Waasdorp; Golden-Mason, Lucy; Brocato, Megan; Krull, Mona; Narkewicz, Michael R; Rosen, Hugo R

2010-08-30

Vertical transmission accounts for the majority of pediatric cases of hepatitis C viral (HCV) infection. In contrast to the adult population who develop persistent viremia in approximately 80% of cases following exposure, the rate of mother-to-child transmission (2-6%) is strikingly low. Protection from vertical transmission likely requires the coordination of multiple components of the immune system. Placenta and decidua provide a direct connection between mother and infant. We hypothesized that innate immune responses would differ across the three compartments (decidua, placenta and cord blood) and that hepatitis C exposure would modify innate immunity in these tissues. The study was comprised of HCV-infected and healthy control mother and infant pairs from whom cord blood, placenta and decidua were collected with isolation of mononuclear cells. Multiparameter flow cytometry was performed to assess the phenotype, intracellular cytokine production and cytotoxicity of the cells. In keeping with a model where the maternal-fetal interface provides antiviral protection, we found a gradient in proportional frequencies of NKT and gammadelta-T cells being higher in placenta than cord blood. Cytotoxicity of NK and NKT cells was enhanced in placenta and placental NKT cytotoxicity was further increased by HCV infection. HCV exposure had multiple effects on innate cells including a decrease in activation markers (CD69, TRAIL and NKp44) on NK cells and a decrease in plasmacytoid dendritic cells in both placenta and cord blood of exposed infants. In summary, the placenta represents an active innate immunological organ that provides antiviral protection against HCV transmission in the majority of cases; the increased incidence in preterm labor previously described in HCV-seropositive mothers may be related to enhanced cytotoxicity of NKT cells.

Holographic cinematography of time-varying reflecting and time-varying phase objects using a Nd:YAG laser

Science.gov (United States)

Decker, A. J.

1982-01-01

The use of a Nd:YAG laser to record holographic motion pictures of time-varying reflecting objects and time-varying phase objects is discussed. Sample frames from both types of holographic motion pictures are presented. The holographic system discussed is intended for three-dimensional flow visualization of the time-varying flows that occur in jet-engine components.

Genome-wide single-generation signatures of local selection in the panmictic European eel

DEFF Research Database (Denmark)

Pujolar, J. M.; Jacobsen, M. W.; Als, Thomas Damm

2014-01-01

Next-generation sequencing and the collection of genome-wide data allow identifying adaptive variation and footprints of directional selection. Using a large SNP data set from 259 RAD-sequenced European eel individuals (glass eels) from eight locations between 34 and 64oN, we examined the patterns...... of genome-wide genetic diversity across locations. We tested for local selection by searching for increased population differentiation using FST-based outlier tests and by testing for significant associations between allele frequencies and environmental variables. The overall low genetic differentiation...... with single-generation signatures of spatially varying selection acting on glass eels. After screening 50 354 SNPs, a total of 754 potentially locally selected SNPs were identified. Candidate genes for local selection constituted a wide array of functions, including calcium signalling, neuroactive ligand...

CFD comparison with centrifugal compressor measurements on a wide operating range

Directory of Open Access Journals (Sweden)

Arnou D.

2013-04-01

Full Text Available Centrifugal compressors are widely used in industrial applications thanks to their high efficiency. They are able to provide a wide operating range before reaching the flow barrier or surge limits. Performances and range are described by compressor maps obtained experimentally. After a description of performance test rig, this article compares measured centrifugal compressor performances with computational fluid dynamics results. These computations are performed at steady conditions with R134a refrigerant as fluid. Navier-Stokes equations, coupled with k-ε turbulence model, are solved by the commercial software ANSYS-CFX by means of volume finite method. Input conditions are varied in order to calculate several speed lines. Theoretical isentropic efficiency and theoretical surge line are finally compared to experimental data.

Cytomegalovirus prevalence and transmission after islet allograft transplant in patients with type 1 diabetes mellitus.

Science.gov (United States)

Hafiz, Muhammad M; Poggioli, Raffaella; Caulfield, Aileen; Messinger, Shari; Geiger, Milene C; Baidal, David A; Froud, Tatiana; Ferreira, Jacqueline V; Tzakis, Andreas G; Ricordi, Camillo; Alejandro, Rodolfo

2004-10-01

Cytomegalovirus (CMV) serological status of transplant donors and recipients has important implications on antiviral prophylaxis, morbidity/mortality, donor selection and hospital stay. We evaluated CMV prevalence in our islet transplant candidates (ITC) in comparison with organ donors. We correlated the CMV serological status of our ITC with serology for Epstein-Barr virus and Parvovirus B19, auto-antibodies, patient's age, age at DM onset, duration of DM, gender, race, ABO group, HLA haplotype and C-peptide levels. Cytomegalovirus transmission after islet transplant using the Edmonton regimen was also evaluated. Cytomegalovirus seropositivity varied according to patient group, age, gender and race. Type 1 DM patients had reduced odds of CMV seropositivity when compared with organ donors. In all groups studied, older patients, females, and non-Caucasians were more likely to be CMV seropositive. In addition, no CMV reactivation, infection or disease was observed among our transplanted patients using this steroid-free regimen even after donor/recipient CMV mismatch.

Enteric parasitic infection among antiretroviral therapy Naïve HIV-seropositive people: Infection begets infection-experience from Eastern India

Directory of Open Access Journals (Sweden)

Suman Mitra

2016-01-01

Full Text Available Context: Parasitic opportunistic infections (POIs frequently occur in HIV/AIDS patients and affect the quality of life. Aims: This study assessing the standard organisms in the stool of HIV-positive patients, their comparison with HIV-negative controls, their relation with various factors, is the first of its kind in the eastern part of India. Settings and Design: hospital-based case-control study. Materials and Methods: A total of 194 antiretroviral therapy naïve HIV-positive patients (18-60 years were taken as cases and 98 age- and sex-matched HIV-negative family members as controls. Demographical, clinical, biochemical, and microbiological parameters were studied. Statistical Analysis Used: Odds ratio, 95% confidence interval, and P (350 cells/μl Cryptosporidium was the most common POI. Mean CD4 count was significantly (P < 0.001 lower among people having multiple infections. Male sex, hemoglobin <10 g/dl, WHO Clinical Stage 3 or 4, tuberculosis, absolute eosinophil count of more than 540/dl, CD4 count <350 cells/μl, and seroconcordance of spouses were significantly associated with HIV-seropositive cases having POI (P < 0.05. Conclusions: Physicians should advise HIV-infected patients to undergo routine evaluation for POI, and provision of chemoprophylaxis should be made in appropriate settings.

Seroprevalence and distribution of arboviral infections among rural Kenyan adults: A cross-sectional study

Directory of Open Access Journals (Sweden)

Schoepp Randal J

2011-07-01

Full Text Available Abstract Background Arthorpod-borne viruses (arboviruses cause wide-spread morbidity in sub-Saharan Africa, but little research has documented the burden and distribution of these pathogens. Methods Using a population-based, cross-sectional study design, we administered a detailed questionnaire and used ELISA to test the blood of 1,141 healthy Kenyan adults from three districts for the presence of anti-viral Immunoglobulin G (IgG antibodies to the following viruses: dengue (DENV, West Nile (WNV, yellow fever (YFV, Chikungunya (CHIKV, and Rift Valley fever (RVFV. Results Of these, 14.4% were positive for DENV, 9.5% were WNV positive, 9.2% were YFV positive, 34.0% were positive for CHIKV and 0.7% were RVFV positive. In total, 46.6% had antibodies to at least one of these arboviruses. Conclusions For all arboviruses, district of residence was strongly associated with seropositivity. Seroprevalence to YFV, DENV and WNV increased with age, while there was no correlation between age and seropositivity for CHIKV, suggesting that much of the seropositivity to CHIKV is due to sporadic epidemics. Paradoxically, literacy was associated with increased seropositivity of CHIKV and DENV.

System-wide versus component-specific trust using multiple aids.

Science.gov (United States)

Keller, David; Rice, Stephen

2010-01-01

Previous research in operator trust toward automated aids has focused primarily on single aids. The current study focuses on how operator trust is affected by the presence of multiple aids. Two competing theories of multiple-trust are presented. A component-specific trust theory predicts that operators will differentially place their trust in automated aids that vary in reliability. A system-wide trust theory predicts that operators will treat multiple imperfect aids as one "system" and merge their trust across aids despite differences in the aids' reliability. A simulated flight task was used to test these theories, whereby operators performed a pursuit tracking task while concurrently monitoring multiple system gauges that were augmented with perfect or imperfect automated aids. The data revealed that a system-wide trust theory best predicted the data; operators merged their trust across both aids, behaving toward a perfectly reliable aid in the same manner as they did towards unreliable aids.

Association of conjunctival and corneal calcification with vascular calcification among hepatitis-C-seropositive hemodialysis patients.

Science.gov (United States)

AbouSeif, Khaled; Sany, Dawlat; Elshahawy, Yasser; Seddik, Ayman; Rahman, Khedr; Gaber, Moustapha

2016-01-01

Disorders associated with the hepatitis C virus (HCV) have been reported including cardiovascular, metabolic, and central nervous system diseases. Since chronic HCV infections may be curable, their identification as causal contributors to cardiovascular risk could offer new perspectives in the prevention of cardiovascular disease. The aim of this study is to investigate the association between HCV and aortic arch calcification (AAC) and corneal and conjunctival calcification (CCC) in maintenance hemodialysis (MHD) patients; further, we assessed the correlation of CCC with vascular calcification. A total of 100 patients undergoing hemodialysis (HD) in our hospital were included in this study. Patients underwent a complete ocular examination including intraocular pressure, and CCC was looked for by slit lamp and fundoscopy. CCC was graded according to modified Porter and Crombie classification system described by Tokuyama et al. Helical computerized tomographic chest examination was used to evaluate the grading of AAC. Demographic, hematological, biochemical, and dialysis-related data were obtained. There was significant difference between seropositive (n = 51) and seronegative patients (n = 49) regarding grading of AAC and CCC (P <0.001). Significant positive correlation was found between grading of CCC, AAC, age (P <0.001), duration on HD (P <0.001), HCV-antibody positivity (P <0.001), serum calcium level (P <0.001), serum phosphorus level (P <0.001), calcium × phosphorus product (P <0.001), and i-parathormone level (P < 0.001). In addition, CCC grading positively correlated with AAC. Our results suggest that patients undergoing HD infected with the HCV have high degree of CCC, AAC, and mineral metabolism disorder. The strong correlation between CCC and AAC indicates that CCC evaluation is an easy, fast, non-invasive method, and might be used as an indirect indicator to detect vascular calcification in patients undergoing MHD.

Association of conjunctival and corneal calcification with vascular calcification among hepatitis-C-seropositive hemodialysis patients

Directory of Open Access Journals (Sweden)

Khaled AbouSeif

2016-01-01

Full Text Available Disorders associated with the hepatitis C virus (HCV have been reported including cardiovascular, metabolic, and central nervous system diseases. Since chronic HCV infections may be curable, their identification as causal contributors to cardiovascular risk could offer new perspectives in the prevention of cardiovascular disease. The aim of this study is to investigate the association between HCV and aortic arch calcification (AAC and corneal and conjunctival calcification (CCC in maintenance hemodialysis (MHD patients; further, we assessed the correlation of CCC with vascular calcification. A total of 100 patients undergoing hemodialysis (HD in our hospital were included in this study. Patients underwent a complete ocular examination including intraocular pressure, and CCC was looked for by slit lamp and fundoscopy. CCC was graded according to modified Porter and Crombie classification system described by Tokuyama et al. Helical computerized tomographic chest examination was used to evaluate the grading of AAC. Demographic, hematological, biochemical, and dialysis-related data were obtained. There was significant difference between seropositive (n = 51 and seronegative patients (n = 49 regarding grading of AAC and CCC (P <0.001. Significant positive correlation was found between grading of CCC, AAC, age (P <0.001, duration on HD (P <0.001, HCV-antibody positivity (P <0.001, serum calcium level (P <0.001, serum phosphorus level (P <0.001, calcium × phosphorus product (P <0.001, and i-parathormone level (P < 0.001. In addition, CCC grading positively correlated with AAC. Our results suggest that patients undergoing HD infected with the HCV have high degree of CCC, AAC, and mineral metabolism disorder. The strong correlation between CCC and AAC indicates that CCC evaluation is an easy, fast, non-invasive method, and might be used as an indirect indicator to detect vascular calcification in patients undergoing MHD.

Semen Bacterial Concentrations and HIV-1 RNA Shedding Among HIV-1–Seropositive Kenyan Men

Science.gov (United States)

Srinivasan, Sujatha; Huang, Dandi; Ko, Daisy L.; Sanders, Eduard J.; Peshu, Norbert M.; Krieger, John N.; Muller, Charles H.; Coombs, Robert W.; Fredricks, David N.; Graham, Susan M.

2017-01-01

Introduction: HIV-1 is transmitted through semen from men to their sexual partners. Genital infections can increase HIV-1 RNA shedding in semen, but shedding also occurs in the absence of typical pathogens. We hypothesized that higher bacterial concentrations in semen would be associated with higher HIV-1 RNA levels. Methods: We analyzed semen samples from 42 HIV-1–seropositive Kenyan men using quantitative polymerase chain reaction (PCR) to assess bacterial concentrations and real-time PCR to measure HIV-1 RNA levels. Generalized estimation equations were used to evaluate associations between these 2 measures. Broad-range 16S rRNA gene PCR with pyrosequencing was performed on a subset of 13 samples to assess bacterial community composition. Results: Bacteria were detected in 96.6% of 88 samples by quantitative PCR. Semen bacterial concentration and HIV-1 RNA levels were correlated 0.30 (P = 0.01). The association between bacterial concentration and HIV-1 RNA detection was not significant after adjustment for antiretroviral therapy (ART) (adjusted odds ratio: 1.27, 95% CI: 0.84 to 1.91). Factors associated with semen bacterial concentration included insertive anal sex (adjusted beta 0.92, 95% CI: 0.12 to 1.73) and ART use (adjusted beta: −0.77, 95% CI: −1.50 to 0.04). Among 13 samples with pyrosequencing data, Corynebacterium spp., Staphylococcus spp., and Streptococcus spp. were most frequently detected. Conclusion: Most of these HIV-1–infected men had bacteria in their semen. ART use was associated with undetectable semen HIV-1 RNA and lower semen bacterial concentrations, whereas insertive anal sex was associated with higher bacterial concentrations. Additional studies evaluating the relationship between semen bacteria, inflammation, mucosal immunity, and HIV-1 shedding are needed to understand implications for HIV-1 transmission. PMID:27861240

Response-only modal identification using random decrement algorithm with time-varying threshold level

International Nuclear Information System (INIS)

Lin, Chang Sheng; Tseng, Tse Chuan

2014-01-01

Modal Identification from response data only is studied for structural systems under nonstationary ambient vibration. The topic of this paper is the estimation of modal parameters from nonstationary ambient vibration data by applying the random decrement algorithm with time-varying threshold level. In the conventional random decrement algorithm, the threshold level for evaluating random dec signatures is defined as the standard deviation value of response data of the reference channel. The distortion of random dec signatures may be, however, induced by the error involved in noise from the original response data in practice. To improve the accuracy of identification, a modification of the sampling procedure in random decrement algorithm is proposed for modal-parameter identification from the nonstationary ambient response data. The time-varying threshold level is presented for the acquisition of available sample time history to perform averaging analysis, and defined as the temporal root-mean-square function of structural response, which can appropriately describe a wide variety of nonstationary behaviors in reality, such as the time-varying amplitude (variance) of a nonstationary process in a seismic record. Numerical simulations confirm the validity and robustness of the proposed modal-identification method from nonstationary ambient response data under noisy conditions.

UNUSUALLY WIDE BINARIES: ARE THEY WIDE OR UNUSUAL?

International Nuclear Information System (INIS)

Kraus, Adam L.; Hillenbrand, Lynne A.

2009-01-01

We describe an astrometric and spectroscopic campaign to confirm the youth and association of a complete sample of candidate wide companions in Taurus and Upper Sco. Our survey found 15 new binary systems (three in Taurus and 12 in Upper Sco) with separations of 3''-30'' (500-5000 AU) among all of the known members with masses of 2.5-0.012 M sun . The total sample of 49 wide systems in these two regions conforms to only some expectations from field multiplicity surveys. Higher mass stars have a higher frequency of wide binary companions, and there is a marked paucity of wide binary systems near the substellar regime. However, the separation distribution appears to be log-flat, rather than declining as in the field, and the mass ratio distribution is more biased toward similar-mass companions than the initial mass function or the field G-dwarf distribution. The maximum separation also shows no evidence of a limit at ∼ sun . We attribute this result to the post-natal dynamical sculpting that occurs for most field systems; our binary systems will escape to the field intact, but most field stars are formed in denser clusters and undergo significant dynamical evolution. In summary, only wide binary systems with total masses ∼ sun appear to be 'unusually wide'.

Antibodies to adult T-cell leukemia-virus-associated antigen (ATLA) in sera from patients with ATL and controls in Japan: a nation-wide sero-epidemiologic study.

Science.gov (United States)

Hinuma, Y; Komoda, H; Chosa, T; Kondo, T; Kohakura, M; Takenaka, T; Kikuchi, M; Ichimaru, M; Yunoki, K; Sato, I; Matsuo, R; Takiuchi, Y; Uchino, H; Hanaoka, M

1982-06-15

A nation-wide sero-epidemiologic survey of adult T-cell leukemia virus (ATLV), detected es anti-ATLA (ATLV-associated antigen), was made in Japan. Sera from adult donors in 15 different locations were screened for anti-ATLA. High incidences (6 to 37%) of antibody-positive donors were found in seven regions, one in northern Japan, and the others in southwestern regions. These areas are ATLV-endemic areas corresponding to ATL-endemic areas. Examination of sera from healthy donors aged 6 to 80 years in ATL-endemic areas showed an age-dependent increase of seropositive donors with a maximum of about 30% at 40 years of age. Anti-ATLA was found in all but two of 142 patients with ATL. Anti-ATLA-positive patients with ATL were mainly found in ATLV-endemic areas, and only a few in ATL-nonendemic areas. Six patients with cutaneous T-cell lymphoma in ATLV-nonendemic areas gave a negative reaction for anti-ATLA. The geometric mean titer of anti-ATLA of patients with ATL was higher than that of healthy donors.

A varying-α brane world cosmology

International Nuclear Information System (INIS)

Youm, Donam

2001-08-01

We study the brane world cosmology in the RS2 model where the electric charge varies with time in the manner described by the varying fine-structure constant theory of Bekenstein. We map such varying electric charge cosmology to the dual variable-speed-of-light cosmology by changing system of units. We comment on cosmological implications for such cosmological models. (author)

Moveout analysis of wide-azimuth data in the presence of lateral velocity variation

KAUST Repository

Takanashi, Mamoru

2012-05-01

Moveout analysis of wide-azimuth reflection data seldom takes into account lateral velocity variations on the scale of spreadlength. However, velocity lenses (such as channels and reefs) in the overburden can cause significant, laterally varying errors in the moveout parameters and distortions in data interpretation. Here, we present an analytic expression for the normal-moveout (NMO) ellipse in stratified media with lateral velocity variation. The contribution of lateral heterogeneity (LH) is controlled by the second derivatives of the interval vertical traveltime with respect to the horizontal coordinates, along with the depth and thickness of the LH layer. This equation provides a quick estimate of the influence of velocity lenses and can be used to substantially mitigate the lens-induced distortions in the effective and interval NMO ellipses. To account for velocity lenses in nonhyperbolic moveout inversion of wide-azimuth data, we propose a prestack correction algorithm that involves computation of the lens-induced traveltime distortion for each recorded trace. The overburden is assumed to be composed of horizontal layers (one of which contains the lens), but the target interval can be laterally heterogeneous with dipping or curved interfaces. Synthetic tests for horizontally layered models confirm that our algorithm accurately removes lens-related azimuthally varying traveltime shifts and errors in the moveout parameters. The developed methods should increase the robustness of seismic processing of wide-azimuth surveys, especially those acquired for fracture-characterization purposes. © 2012 Society of Exploration Geophysicists.

Moveout analysis of wide-azimuth data in the presence of lateral velocity variation

KAUST Repository

Takanashi, Mamoru; Tsvankin, Ilya

2012-01-01

Moveout analysis of wide-azimuth reflection data seldom takes into account lateral velocity variations on the scale of spreadlength. However, velocity lenses (such as channels and reefs) in the overburden can cause significant, laterally varying errors in the moveout parameters and distortions in data interpretation. Here, we present an analytic expression for the normal-moveout (NMO) ellipse in stratified media with lateral velocity variation. The contribution of lateral heterogeneity (LH) is controlled by the second derivatives of the interval vertical traveltime with respect to the horizontal coordinates, along with the depth and thickness of the LH layer. This equation provides a quick estimate of the influence of velocity lenses and can be used to substantially mitigate the lens-induced distortions in the effective and interval NMO ellipses. To account for velocity lenses in nonhyperbolic moveout inversion of wide-azimuth data, we propose a prestack correction algorithm that involves computation of the lens-induced traveltime distortion for each recorded trace. The overburden is assumed to be composed of horizontal layers (one of which contains the lens), but the target interval can be laterally heterogeneous with dipping or curved interfaces. Synthetic tests for horizontally layered models confirm that our algorithm accurately removes lens-related azimuthally varying traveltime shifts and errors in the moveout parameters. The developed methods should increase the robustness of seismic processing of wide-azimuth surveys, especially those acquired for fracture-characterization purposes. © 2012 Society of Exploration Geophysicists.

Toward the integration of European natural gas markets:A time-varying approach

International Nuclear Information System (INIS)

Renou-Maissant, Patricia

2012-01-01

Over the past fifteen years, European gas markets have radically changed. In order to build a single European gas market, a new regulatory framework has been established through three European Gas Directives. The purpose of this article is to investigate the impact of the reforms in the natural gas industry on consumer prices, with a specific focus on gas prices for industrial use. The strength of the relationship between the industrial gas prices of six western European countries is studied by testing the Law of One Price for the period 1991–2009. Estimations were carried out using both cointegration analysis and time-varying parameter models. Results highlight an emerging and on-going process of convergence between the industrial gas prices in western Europe since 2001 for the six EU member states. The strength and the level of convergence differ widely between countries. Strong integration of gas markets in continental Europe, except for the Belgian market, has been established. It appears that the convergence process between continental countries and the UK is not completed. Thus, the integration of European gas markets remains an open issue and the question of how far integration will proceed will still be widely discussed in the coming years. - Highlights: ► We investigate the integration of European natural gas markets. ► We use both cointegration analysis and time-varying parameter models. ► We show the failure of cointegration techniques to take account of evolving processes. ► An emerging and on-going process of convergence between the industrial gas prices is at work. ► Strong integration of gas markets in continental Europe has been established.

HLA-A02:01-restricted epitopes identified from the herpes simplex virus tegument protein VP11/12 preferentially recall polyfunctional effector memory CD8+ T cells from seropositive asymptomatic individuals and protect humanized HLA-A*02:01 transgenic mice against ocular herpes.

Science.gov (United States)

Srivastava, Ruchi; Khan, Arif A; Spencer, Doran; Vahed, Hawa; Lopes, Patricia P; Thai, Nhi Thi Uyen; Wang, Christine; Pham, Thanh T; Huang, Jiawei; Scarfone, Vanessa M; Nesburn, Anthony B; Wechsler, Steven L; BenMohamed, Lbachir

2015-03-01

The HSV type 1 tegument virion phosphoprotein (VP) 11/12 (VP11/12) is a major Ag targeted by CD8(+) T cells from HSV-seropositive individuals. However, whether and which VP11/12 epitope-specific CD8(+) T cells play a role in the "natural" protection seen in seropositive healthy asymptomatic (ASYMP) individuals (who have never had clinical herpes disease) remain to be determined. In this study, we used multiple prediction computer-assisted algorithms to identify 10 potential HLA-A*02:01-restricted CD8(+) T cell epitopes from the 718-aa sequence of VP11/12. Three of 10 epitopes exhibited high-to-moderate binding affinity to HLA-A*02:01 molecules. In 10 sequentially studied HLA-A*02:01-positive and HSV-1-seropositive ASYMP individuals, the most frequent, robust, and polyfunctional effector CD8(+) T cell responses, as assessed by a combination of tetramer frequency, granzyme B, granzyme K, perforin, CD107(a/b) cytotoxic degranulation, IFN-γ, and multiplex cytokines assays, were predominantly directed against three epitopes: VP11/1266-74, VP11/12220-228, and VP11/12702-710. Interestingly, ASYMP individuals had a significantly higher proportion of CD45RA(low)CCR7(low)CD44(high)CD62L(low)CD27(low)CD28(low)CD8(+) effector memory CD8(+) T cells (TEMs) specific to the three epitopes, compared with symptomatic individuals (with a history of numerous episodes of recurrent ocular herpetic disease). Moreover, immunization of HLA-A*02:01 transgenic mice with the three ASYMP CD8(+) TEM cell epitopes induced robust and polyfunctional epitope-specific CD8(+) TEM cells that were associated with a strong protective immunity against ocular herpes infection and disease. Our findings outline phenotypic and functional features of protective HSV-specific CD8(+) T cells that should guide the development of an effective T cell-based herpes vaccine. Copyright © 2015 by The American Association of Immunologists, Inc.

Associations between the proportion of Salmonella seropositive slaughter pigs and the presence of herd level risk factors for introduction and transmission of Salmonella in 34 Danish organic, outdoor (non-organic) and indoor finishing-pig farms

DEFF Research Database (Denmark)

Zheng, D.M.; Bonde, Marianne; Sørensen, Jan Tind

2007-01-01

This paper evaluates the association between herd level risk factors for introduction and transmission of Salmonella in farms with three different production systems: organic, outdoor (non-organic) and indoor finishing-pig farms, and the presence of seropositive animals in the herds. Potential risk...... factors for Salmonella in the three pig production systems were identified through a literature review, and management information as well as serological data were collected in 34 pig farms: 11 organic farms, 12 outdoor farms, and 11 indoor farms. There were no general differences in the proportion...

Model Study of Wave Overtopping of Marine Structure for a Wide Range of Geometric Parameters

DEFF Research Database (Denmark)

Kofoed, Jens Peter

2000-01-01

The objective of the study described in this paper is to enable estimation of wave overtopping rates for slopes/ramps given by a wide range of geometric parameters when subjected to varying wave conditions. To achieve this a great number of model tests are carried out in a wave tank using irregul...... 2-D waves. On the basis of the first part of these tests an exponential overtopping expression for a linear slope, including the effect of limited draught and varying slope angle, is presented. The plans for further tests with other slope geometries are described....

Meta-analysis of the association between N-methyl-d-aspartate receptor antibodies and schizophrenia, schizoaffective disorder, bipolar disorder, and major depressive disorder.

Science.gov (United States)

Pearlman, Daniel M; Najjar, Souhel

2014-08-01

/NR2B antibody titers determined by ELISA were significantly higher among participants with first-episode schizophrenia (Pschizoaffective, bipolar, or major depressive disorders are collectively about three times more likely to have elevated NMDAR antibody titers compared with healthy controls based on high-specificity, but not low-specificity, seropositivity thresholds, though considerable methodological and statistical heterogeneity exists. Evidence concerning the effect of disease state and time of serum acquisition is varied and consistent, respectively. Adequately powered longitudinal studies employing standardized assay methods and seropositivity threshold definitions, and quantifying NMDAR antibodies in both sera and cerebrospinal fluid are needed to further elucidate the clinical and pathophysiological implications of this association. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

A quantitative risk assessment of multiple factors influencing HIV/AIDS transmission through unprotected sex among HIV-seropositive men.

Science.gov (United States)

Gerbi, Gemechu B; Habtemariam, Tsegaye; Tameru, Berhanu; Nganwa, David; Robnett, Vinaida

2012-01-01

The objective of this study is to conduct a quantitative risk assessment of multiple factors influencing HIV/AIDS transmission through unprotected sexual practices among HIV-seropositive men. A knowledgebase was developed by reviewing different published sources. The data were collected from different sources including Centers for Disease Control and Prevention, selected journals, and reports. The risk pathway scenario tree was developed based on a comprehensive review of published literature. The variables are organized into nine major parameter categories. Monte Carlo simulations for the quantitative risk assessment of HIV/AIDS transmission was executed with the software @Risk 4.0 (Palisade Corporation). Results show that the value for the likelihood of unprotected sex due to having less knowledge about HIV/AIDS and negative attitude toward condom use and safer sex ranged from 1.24 × 10(-5) to 8.47 × 10(-4) with the mean and standard deviation of 1.83 × 10(-4) and 8.63 × 10(-5), respectively. The likelihood of unprotected sex due to having greater anger-hostility, anxiety, less satisfied with aspects of life, and greater depressive symptoms ranged from 2.76 × 10(-9) to 5.34 × 10(-7) with the mean and standard deviation of 5.23 × 10(-8) and 3.58 × 10(-8), respectively. The findings suggest that HIV/AIDS research and intervention programs must be focused on behavior, and the broader setting within which individual risky behaviors occur.

The emergent concern of seropositive status of hepatitis-b virus and hepatitis-c virus in the pregnant females attending a tertiary care hospital

International Nuclear Information System (INIS)

Kumari, K.

2015-01-01

Viral hepatitis is a global problem affecting millions of people including pregnant females. Viral hepatitis during pregnancy is associated with both maternal and neonatal mortality and morbidity. This study was an attempt to assess the seropositive status of hepatitis-B and C infection among pregnant women in Karachi, Pakistan. Methods: This cross sectional observational study was conducted at Sir Syed College of Medical Sciences and Trust Hospital, Karachi from January to September 2012. Patients were recruited by consecutive sampling. At the booking visit, blood was drawn and tested for HbsAg and Anti HCV by Eliza method. Results: Among the screened population, 2% were reactive for HBV and 13.3% were found reactive for HCV. All HbsAg and HCV positive pregnant patients had one or more than one delivery. Conclusion: In our study sample, high frequency of HBV and HCV is suggestive of the importance of antenatal screening of these viral diseases, which has impact on the mother as well as the new born baby. HCV was more common as compared to HBV which is quite alarming. (author)

Lichen Persistence and Recovery in Response to Varied Volcanic Disturbances

Science.gov (United States)

Nelson, P.; Wheeler, T. B.

2015-12-01

Volcanic eruptions produce many ecological disturbances that structure vegetation. While lichens are sensitive to disturbances, little is known about their responses to volcanic disturbances, except for colonization of lava. We examined lichen community responses through time to different disturbances produced by the May 1, 2008 eruption of Volcan Chaiten in south-central Chile. Pre-eruption vegetation near the volcano was old-growth Valdivian temperate rainforest dominated by closed-canopy Nothofagus sp... In 2012, we installed thirteen 1-acre plots across volcanic disturbance zones on which a time-constrained search was done for all macrolichen species, each of which was assigned an approximate log10 categorical abundance. We also installed a 0.2 m2 quadrat on two representative trees per plot for repeat photography of lichen cover. We remeasured at least one plot per disturbance zone in 2014 and re-photographed tree quadrats in 2013 and 2014. We then analyzed species composition and abundance differences among disturbance zones. In 2012, the blast (pyroclastic density flow), scorch (standing scorched forest at the edge of the blast) and deep tephra (>10 cm) zones had the lowest lichen species richness (5-13 species), followed by reference (unimpacted) and shallow (lichen species since 2012 while the light tephra and reference were essentially unchanged. Gravel rain, gravel rain + pumice and flooded forest plots all had about the same number of species in 2014 as 2012. Lichen colonization and growth in tree quadrats varied widely, from very little colonization in the blast to prolific colonization in the gravel rain + pumice zone. Lichen's varied responses to different volcanic disturbances were attributable to varying degrees of mortality and subsequent availability of substrate, quantity of light and removal of competitors. While sensitive to disturbance, lichens are apparently resilient to and can quickly recolonize after a variety of large, violent volcanic

Descriptive systematic review of sub-Saharan African studies on the ...

African Journals Online (AJOL)

alcohol use definitions. Overall, users of alcohol and especially problem drinkers were more likely to be HIV seropositive (HIV+) than non-users, frequency or quantity of alcohol use was positively associated with HIV prevalence, and the association varied by gender. The use of alcohol in sexual contexts was significantly ...

Zhang neural network for online solution of time-varying convex quadratic program subject to time-varying linear-equality constraints

International Nuclear Information System (INIS)

Zhang Yunong; Li Zhan

2009-01-01

In this Letter, by following Zhang et al.'s method, a recurrent neural network (termed as Zhang neural network, ZNN) is developed and analyzed for solving online the time-varying convex quadratic-programming problem subject to time-varying linear-equality constraints. Different from conventional gradient-based neural networks (GNN), such a ZNN model makes full use of the time-derivative information of time-varying coefficient. The resultant ZNN model is theoretically proved to have global exponential convergence to the time-varying theoretical optimal solution of the investigated time-varying convex quadratic program. Computer-simulation results further substantiate the effectiveness, efficiency and novelty of such ZNN model and method.

Spacetime-varying couplings and Lorentz violation

International Nuclear Information System (INIS)

Kostelecky, V. Alan; Lehnert, Ralf; Perry, Malcolm J.

2003-01-01

Spacetime-varying coupling constants can be associated with violations of local Lorentz invariance and CPT symmetry. An analytical supergravity cosmology with a time-varying fine-structure constant provides an explicit example. Estimates are made for some experimental constraints

Altered Associations between Pain Symptoms and Brain Morphometry in the Pain Matrix of HIV-Seropositive Individuals.

Science.gov (United States)

Castillo, Deborrah; Ernst, Thomas; Cunningham, Eric; Chang, Linda

2018-03-01

Pain remains highly prevalent in HIV-seropositive (HIV+) patients despite their well-suppressed viremia with combined antiretroviral therapy. Investigating brain abnormalities within the pain matrix, and in relation to pain symptoms, in HIV+ participants may provide objective biomarkers and insights regarding their pain symptoms. We used Patient-Reported Outcome Measurement Information System (PROMIS®) pain questionnaire to evaluate pain symptoms (pain intensity, pain interference and pain behavior), and structural MRI to assess brain morphometry using FreeSurfer (cortical area, cortical thickness and subcortical volumes were evaluated in 12 regions within the pain matrix). Compared to seronegative (SN) controls, HIV+ participants had smaller surface areas in prefrontal pars triangularis (right: p = 0.04, left: p = 0.007) and right anterior cingulate cortex (p = 0.03) and smaller subcortical regions (thalamus: p ≤ 0.003 bilaterally; right putamen: p = 0.01), as well as higher pain scores (pain intensity-p = 0.005; pain interference-p = 0.008; pain-behavior-p = 0.04). Furthermore, higher pain scores were associated with larger cortical areas, thinner cortices and larger subcortical volumes in HIV+ participants; but smaller cortical areas, thicker cortices and smaller subcortical volumes in SN controls (interaction-p = 0.009 to p = 0.04). These group differences in the pain-associated brain abnormalities suggest that HIV+ individuals have abnormal pain responses. Since these abnormal pain-associated brain regions belong to the affective component of the pain matrix, affective symptoms may influence pain perception in HIV+ patients and should be treated along with their physical pain symptoms. Lastly, associations of lower pain scores with better physical or mental health scores, regardless of HIV-serostatus (p < 0.001), suggest adequate pain treatment would lead to better quality of life in all participants.

Seropositivity to Leptospira interrogans serovar Bratislava associated to reproductive problems without significant biochemical or hematological alterations in horses Soropositividade para Leptospira interrogans serovar Bratislava associada a falhas reprodutivas sem alterações hematológicas e bioquímicas significativas em cavalos

Directory of Open Access Journals (Sweden)

Melissa Pinna

2010-10-01

Full Text Available The objective was to study haematological and biochemical alterations associated to seropositivity to Leptospira interrogans serovar Bratislava infection in horses with reproductive alterations, such as neonatal deaths, embryonic deaths and abortions. A flock of mares with poor reproductive performance was studied. Eighty-two (58.6% were seropositive (titre 200; 72 of those (87.8% for Bratislava. Slight haematological and biochemical alterations were observed, being more frequent (PO objetivo deste trabalho foi estudar alterações hematológicas e bioquímicas associadas à soropositividade para Leptospira interrogans sorovar Bratislava em cavalos com alterações reprodutivas, tais como mortes neonatais, absorção embrionária e abortamentos. Um rebanho de éguas com baixos índices reprodutivos foi estudado. Oitenta e duas (58,6% foram soropositivas (títulos 200, sendo 72 destas (87,8% para Bratislava. Foram observadas poucas alterações hematológicas e bioquímicas, mais frequentes (P<0,05 em éguas soropositivas do que soronegativas. Cavalos soropositivos para Bratislava não tinham alterações graves nos valores hematológicos e bioquímicos. Esses achados reforçam que esse sorovar seja adaptado de cavalos e cause apenas sintomas brandos, associados a falhas reprodutivas.

Utilization of serology for the diagnosis of suspected Lyme borreliosis in Denmark: Survey of patients seen in general practice

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Skarphedinsson Sigurdur

2010-11-01

Full Text Available Abstract Background Serological testing for Lyme borreliosis (LB is frequently requested by general practitioners for patients with a wide variety of symptoms. Methods A survey was performed in order to characterize test utilization and clinical features of patients investigated for serum antibodies to Borrelia burgdorferi sensu lato. During one calendar year a questionnaire was sent to the general practitioners who had ordered LB serology from patients in three Danish counties (population 1.5 million inhabitants. Testing was done with a commercial ELISA assay with purified flagella antigen from a Danish strain of B. afzelii. Results A total of 4,664 patients were tested. The IgM and IgG seropositivity rates were 9.2% and 3.3%, respectively. Questionnaires from 2,643 (57% patients were available for analysis. Erythema migrans (EM was suspected in 38% of patients, Lyme arthritis/disseminated disease in 23% and early neuroborreliosis in 13%. Age 0-15 years and suspected EM were significant predictors of IgM seropositivity, whereas suspected acrodermatitis was a predictor of IgG seropositivity. LB was suspected in 646 patients with arthritis, but only 2.3% were IgG seropositive. This is comparable to the level of seropositivity in the background population indicating that Lyme arthritis is a rare entity in Denmark, and the low pretest probability should alert general practitioners to the possibility of false positive LB serology. Significant predictors for treating the patient were a reported tick bite and suspected EM. Conclusions A detailed description of the utilization of serology for Lyme borreliosis with rates of seropositivity according to clinical symptoms is presented. Low rates of seropositivity in certain patient groups indicate a low pretest probability and there is a notable risk of false positive results. 38% of all patients tested were suspected of EM, although this is not a recommended indication due to a low sensitivity of

Nonlinear radiation transport problems involving widely varying mean free paths

International Nuclear Information System (INIS)

Chapline, G. Jr.; Wood, L.

1976-01-01

In this report a method is given for modifying the Monte-Carlo approach so that one can accurately treat problems that involve both large and small mean free paths. This method purports to offer the advantages of the general Monte Carlo technique as far as relatively great accuracy of simulation of microscopic physical phenomena is concerned, and the advantage of a diffusion theory approach as far as decent time steps in thick problems are concerned; it does suffer from something of the statistical fluctuation problems of the Monte Carlo, although in analytically attenuated and modified form

Sub-isotypic differences in the immunoglobulin G response to Lawsonia intracellularis in vaccinated, seropositive, and equine proliferative enteropathy-affected horses.

Science.gov (United States)

Page, Allen E; Stills, Harold F; Horohov, David W

2014-12-15

In the horse, Lawsonia intracellularis infection results in equine proliferative enteropathy (EPE). While upwards of 100% of weanlings on an endemic farm may seroconvert, only a small percentage (approximately 5%) will develop clinical disease. Cell-mediated immune mechanisms likely play a role in resistance to L. intracellularis and the absence of a L. intracellularis-specific IFN-γ response has been associated with the development of EPE. The goal of this study was to determine whether protection from clinical EPE is associated with the induction of a systemic IgG sub-isotypic response consistent with a Th1-type cytokine response. To describe their L. intracellularis/EPE status, horses enrolled in this study were placed into one of three categories: seropositive-only, vaccinated, and presumptive clinical EPE. An existing ELISA method was modified to detect L. intracellularis-specific IgG(a), IgG(b), and IgG(t) antibodies using the mouse anti-equine hybridomas CVS-48, CVS-39, and CVS-40, respectively. Additionally, the existing ELISA method was used to quantify total IgG antibodies specific for L. intracellularis for comparison between the groups. Total L. intracellularis-specific IgG was found to be significantly higher (pequine IgG sub-isotypes may provide additional information once these become commercially available. Copyright © 2014 Elsevier B.V. All rights reserved.

Path coefficient analysis of zinc dynamics in varying soil environment

International Nuclear Information System (INIS)

Rattan, R.K.; Phung, C.V.; Singhal, S.K.; Deb, D.L.; Singh, A.K.

1994-01-01

Influence of soil properties on labile zinc, as measured by diethylene-triamine pentaacetic acid (DTPA) and zinc-65, and self-diffusion coefficients of zinc was assessed on 22 surface soil samples varying widely in their characteristics following linear regression and path coefficient analysis techniques. DTPA extractable zinc could be predicted from organic carbon status and pH of the soil with a highly significant coefficient of determination (R 2 =0.84 ** ). Ninety seven per cent variation in isotopically exchangeable zinc was explained by pH, clay content and cation exchange capacity (CEC) of soil. The self-diffusion coefficients (DaZn and DpZn) and buffer power of zinc exhibited exponential relationship with soil properties, pH being the most dominant one. Soil properties like organic matter, clay content etc. exhibited indirect effects on zinc diffusion rates via pH only. (author). 13 refs., 6 tabs

Intelligibility and Clarity of Reverberant Speech: Effects of Wide Dynamic Range Compression Release Time and Working Memory

Science.gov (United States)

Reinhart, Paul N.; Souza, Pamela E.

2016-01-01

Purpose: The purpose of this study was to examine the effects of varying wide dynamic range compression (WDRC) release time on intelligibility and clarity of reverberant speech. The study also considered the role of individual working memory. Method: Thirty older listeners with mild to moderately-severe sloping sensorineural hearing loss…

Nonlinearly Activated Neural Network for Solving Time-Varying Complex Sylvester Equation.

Science.gov (United States)

Li, Shuai; Li, Yangming

2013-10-28

The Sylvester equation is often encountered in mathematics and control theory. For the general time-invariant Sylvester equation problem, which is defined in the domain of complex numbers, the Bartels-Stewart algorithm and its extensions are effective and widely used with an O(n³) time complexity. When applied to solving the time-varying Sylvester equation, the computation burden increases intensively with the decrease of sampling period and cannot satisfy continuous realtime calculation requirements. For the special case of the general Sylvester equation problem defined in the domain of real numbers, gradient-based recurrent neural networks are able to solve the time-varying Sylvester equation in real time, but there always exists an estimation error while a recently proposed recurrent neural network by Zhang et al [this type of neural network is called Zhang neural network (ZNN)] converges to the solution ideally. The advancements in complex-valued neural networks cast light to extend the existing real-valued ZNN for solving the time-varying real-valued Sylvester equation to its counterpart in the domain of complex numbers. In this paper, a complex-valued ZNN for solving the complex-valued Sylvester equation problem is investigated and the global convergence of the neural network is proven with the proposed nonlinear complex-valued activation functions. Moreover, a special type of activation function with a core function, called sign-bi-power function, is proven to enable the ZNN to converge in finite time, which further enhances its advantage in online processing. In this case, the upper bound of the convergence time is also derived analytically. Simulations are performed to evaluate and compare the performance of the neural network with different parameters and activation functions. Both theoretical analysis and numerical simulations validate the effectiveness of the proposed method.

Varied line-space gratings: past, present and future

International Nuclear Information System (INIS)

Hettrick, M.C.

1985-08-01

A classically ruled diffraction grating consists of grooves which are equidistant, straight and parallel. Conversely, the so-called ''holographic'' grating (formed by the interfering waves of coherent visible light), although severely constrained by the recording wavelength and recording geometry, has grooves which are typically neither equidistant, straight nor parallel. In contrast, a varied line-space (VLS) grating, in common nomenclature, is a design in which the groove positions are relatively unconstrained yet possess sufficient symmetry to permit mechanical ruling. Such seemingly exotic gratings are no longer only a theoretical curiosity, but have been ruled and used in a wide variety of applications. These include: (1) aberration-corrected normal incidence concave gratings for Seya-Namioka monochromators and optical de-multiplexers, (2) flat-field grazing incidence concave gratings for plasma diagnostics, (3) aberration-corrected grazing incidence plane gratings for space-borne spectrometers, (4) focusing grazing incidence plane grating for synchrotron radiation monochromators, and (5) wavefront generators for visible interferometry of optical surfaces (particularly aspheres). Future prospects of VLS gratings as dispersing elements, wavefront correctors and beamsplitters appear promising. The author discusses the history of VLS gratings, their present applications, and their potential in the future. 61 refs., 24 figs

Comparison of seropositivity of human T lymphotropic virus type 1 in mycosis fungoides patients and normal volunteers: A case-control study and review of literature

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Seirafi Hassan

2009-01-01

Full Text Available Background: There have been controversial reports about the possible association between mycosis fungoides (MF, its leukemic variant Sιzary syndrome (SS and human T lymphotropic virus type 1 (HTLV-1 in different geographical regions. Aims: The purpose of this study was to explore any association between MF and presence of HTLV-1 infection in Iran. Methods: In a case-control setting, 150 clinically and histopathologically proven MF patients had been admitted to the tertiary referral skin center during a 10-year period and another 150 normal volunteers had been compared with each other for the presence of HTLV-1 infection. Enzyme-linked immunosorbent assay (ELISA was used to detect antibodies against HTLV-1, and positive results were confirmed with western blotting. Results: Only three MF patients had HTLV-1 infection, whereas two cases of normal subjects had the infection ( P > 0.05. The only three seropositive MF patients were male and from North-Eastern Iran . Conclusion: This study showed that MF does not correlate with HTLV-1 infection in Iran.

Errors in 'BED'-derived estimates of HIV incidence will vary by place, time and age.

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Timothy B Hallett

2009-05-01

Full Text Available The BED Capture Enzyme Immunoassay, believed to distinguish recent HIV infections, is being used to estimate HIV incidence, although an important property of the test--how specificity changes with time since infection--has not been not measured.We construct hypothetical scenarios for the performance of BED test, consistent with current knowledge, and explore how this could influence errors in BED estimates of incidence using a mathematical model of six African countries. The model is also used to determine the conditions and the sample sizes required for the BED test to reliably detect trends in HIV incidence.If the chance of misclassification by BED increases with time since infection, the overall proportion of individuals misclassified could vary widely between countries, over time, and across age-groups, in a manner determined by the historic course of the epidemic and the age-pattern of incidence. Under some circumstances, changes in BED estimates over time can approximately track actual changes in incidence, but large sample sizes (50,000+ will be required for recorded changes to be statistically significant.The relationship between BED test specificity and time since infection has not been fully measured, but, if it decreases, errors in estimates of incidence could vary by place, time and age-group. This means that post-assay adjustment procedures using parameters from different populations or at different times may not be valid. Further research is urgently needed into the properties of the BED test, and the rate of misclassification in a wide range of populations.

Pathogen exposure varies widely among sympatric populations of wild and domestic felids across the United States.

Science.gov (United States)

Carver, Scott; Bevins, Sarah N; Lappin, Michael R; Boydston, Erin E; Lyren, Lisa M; Alldredge, Mathew; Logan, Kenneth A; Sweanor, Linda L; Riley, Seth P D; Serieys, Laurel E K; Fisher, Robert N; Vickers, T Winston; Boyce, Walter; Mcbride, Roy; Cunningham, Mark C; Jennings, Megan; Lewis, Jesse; Lunn, Tamika; Crooks, Kevin R; Vandewoude, Sue

2016-03-01

Understanding how landscape, host, and pathogen traits contribute to disease exposure requires systematic evaluations of pathogens within and among host species and geographic regions. The relative importance of these attributes is critical for management of wildlife and mitigating domestic animal and human disease, particularly given rapid ecological changes, such as urbanization. We screened > 1000 samples from sympatric populations of puma (Puma concolor), bobcat (Lynx rufus), and domestic cat (Felis catus) across urban gradients in six sites, representing three regions, in North America for exposure to a representative suite of bacterial, protozoal, and viral pathogens (Bartonella sp., Toxoplasma gondii, feline herpesvirus-1, feline panleukopenea virus, feline calicivirus, and feline immunodeficiency virus). We evaluated prevalence within each species, and examined host trait and land cover determinants of exposure; providing an unprecedented analysis of factors relating to potential for infections in domesticated and wild felids. Prevalence differed among host species (highest for puma and lowest for domestic cat) and was greater for indirectly transmitted pathogens. Sex was inconsistently predictive of exposure to directly transmitted pathogens only, and age infrequently predictive of both direct and indirectly transmitted pathogens. Determinants of pathogen exposure were widely divergent between the wild felid species. For puma, suburban land use predicted increased exposure to Bartonella sp. in southern California, and FHV-1 exposure increased near urban edges in Florida. This may suggest interspecific transmission with domestic cats via flea vectors (California) and direct contact (Florida) around urban boundaries. Bobcats captured near urban areas had increased exposure to T. gondii in Florida, suggesting an urban source of prey Bobcats captured near urban areas in Colorado and Florida had higher FIV exposure, possibly suggesting increased intraspecific

Pathogen exposure varies widely among sympatric populations of wild and domestic felids across the United States

Science.gov (United States)

Carver, Scott; Bevins, Sarah N.; Lappin, Michael R.; Boydston, Erin E.; Lyren, Lisa M.; Alldredge, Mathew W.; Logan, Kenneth A.; Sweanor, Linda L.; Riley, Seth P.D.; Serieys, Laurel E.K.; Fisher, Robert N.; Vickers, T. Winston; Boyce, Walter M.; McBride, Roy; Cunnigham, Mark C.; Jennings, Megan; Lewis, Jesse S.; Lunn, Tamika; Crooks, Kevin R.; VandeWoude, Sue

2016-01-01

Understanding how landscape, host, and pathogen traits contribute to disease exposure requires systematic evaluations of pathogens within and among host species and geographic regions. The relative importance of these attributes is critical for management of wildlife and mitigating domestic animal and human disease, particularly given rapid ecological changes, such as urbanization. We screened >1,000 samples from sympatric populations of puma (Puma concolor), bobcat (Lynx rufus) and domestic cat (Felis catus) across urban gradients in six sites, representing three regions, in North America for exposure to a representative suite of bacterial, protozoal and viral pathogens (Bartonella sp., Toxoplasma gondii, feline herpesvirus-1, feline panleukopenea virus, feline calicivirus, feline immunodeficiency virus). We evaluated prevalence within each species, and examined host trait and land cover determinants of exposure-providing an unprecedented analysis of factors relating to potential for infections in domesticated and wild felids. Prevalence differed among host species (highest for puma and lowest for domestic cat) and was greater for indirectly transmitted pathogens. Sex was inconsistently predictive of exposure to directly transmitted pathogens only, and age infrequently predictive of both direct and indirectly transmitted pathogens. Determinants of pathogen exposure were widely divergent between the wild felid species. For puma, suburban landuse predicted increased exposure to Bartonella sp. in southern California, and FHV-1 exposure increased near urban edges in Florida. This may suggest inter-specific transmission with domestic cats via flea vectors (California) and direct contact (Florida) around urban boundaries. Bobcats captured near urban areas had increased exposure to T. gondii in Florida, suggesting an urban source of prey. Bobcats captured near urban areas in Colorado and Florida had higher FIV exposure, possibly suggesting increased intra

JR-curves of wide plates and CT25 specimens

International Nuclear Information System (INIS)

Aurich, D.; Wobst, K.; Krafka, H.

1987-01-01

In connection with the problem of the applicability of the characteristic specimen date - i.e. the initiation and stable crack propagation under maximal loads, together with the elastic-plastic material behaviour - to that of actual components, spot-check type beside tests were conducted using wide-plate central crack, central notch (CCT, CNT) and double external crack (DECT) samples. The material in question was an StE 460 steel. A comparison between the determined values shows that the assessed pressure vessel behaviour differs extensively to the values derived from the CCT and CNT specimens. The corresponding results obtained from the CT25 and DECT specimens vary only slightly in the region of interest and correspond to real vessel values. (orig./DG) [de

Matching Value Propositions with Varied Customer Needs

DEFF Research Database (Denmark)

Heikka, Eija-Liisa; Frandsen, Thomas; Hsuan, Juliana

2018-01-01

Organizations seek to manage varied customer segments using varied value propositions. The ability of a knowledge-intensive business service (KIBS) provider to formulate value propositions into attractive offerings to varied customers becomes a competitive advantage. In this specific business based...... on often highly abstract service offerings, this requires the provider to have a clear overview of its knowledge and resources and how these can be configured to obtain the desired customization of services. Hence, the purpose of this paper is to investigate how a KIBS provider can match value propositions...... with varied customer needs utilizing service modularity. To accomplish this purpose, a qualitative multiple case study is organized around 5 projects allowing within-case and cross-case comparisons. Our findings describe how through the configuration of knowledge and resources a sustainable competitive...

Medication and volume delivery by gravity-driven micro-drip intravenous infusion: potential variations during "wide-open" flow.

Science.gov (United States)

Pierce, Eric T; Kumar, Vikram; Zheng, Hui; Peterfreund, Robert A

2013-03-01

Gravity-driven micro-drip infusion sets allow control of medication dose delivery by adjusting drops per minute. When the roller clamp is fully open, flow in the drip chamber can be a continuous fluid column rather than discrete, countable, drops. We hypothesized that during this "wide-open" state, drug delivery becomes dependent on factors extrinsic to the micro-drip set and is therefore difficult to predict. We conducted laboratory experiments to characterize volume delivery under various clinically relevant conditions of wide-open flow in an in vitro laboratory model. A micro-drip infusion set, plugged into a bag of normal saline, was connected to a high-flow stopcock at the distal end. Vertically oriented IV catheters (gauges 14-22) were connected to the stopcock. The fluid meniscus height in the bag was fixed (60-120 cm) above the outflow point. The roller clamp on the infusion set was in fully open position for all experiments resulting in a continuous column of fluid in the drip chamber. Fluid volume delivered in 1 minute was measured 4 times with each condition. To model resistive effects of carrier flow, volumetric infusion pumps were used to deliver various flow rates of normal saline through a carrier IV set into which a micro-drip infusion was "piggybacked." We also compared delivery by micro-drip infusion sets from 3 manufacturers. The volume of fluid delivered by gravity-driven infusion under wide-open conditions (continuous fluid column in drip chamber) varied 2.9-fold (95% confidence interval, 2.84-2.96) depending on catheter size and fluid column height. Total model resistance of the micro-drip with stopcock and catheter varied with flow rate. Volume delivered by the piggybacked micro-drip decreased up to 29.7% ± 0.8% (mean ± SE) as the carrier flow increased from 0 to 1998 mL/min. Delivery characteristics of the micro-drip infusion sets from 3 different manufacturers were similar. Laboratory simulation of clinical situations with gravity

Toxoplasma seroprevalence in a rural population in France: detection of a household effect

Directory of Open Access Journals (Sweden)

Riche Benjamin

2009-05-01

Full Text Available Abstract Background Toxoplasma gondii, the agent of toxoplasmosis, has a complex life cycle. In humans, the parasite may be acquired either through ingestion of contaminated meat or through oocysts present in the environment. The importance of each source of contamination varies locally according to the environment characteristics and to differences concerning human eating habits and the presence of cats; thus, the risk factors may be determined through fine-scale studies. Here, we searched for factors associated with seropositivity in the population of two adjacent villages in Lorraine region, France. Methods All voluntary inhabitants filled out a questionnaire and gave a blood sample. The seroprevalence was estimated globally and according to the inhabitants' ages using a cubic spline regression. A mixed logistic regression model was used to quantify the effect of individual and household factors on the probability of seropositivity. Results Based on serological results from 273 persons, we estimated seroprevalence to be 47% (95% confidence interval: 41 to 53%. That seroprevalence increased with age: the slope was the steepest up to the age of 40 years (OR = 2.48 per 10-year increment, 95% credibility interval: [1.29 to 5.09], but that increase was not significant afterwards. The probability of seropositivity tended to be higher in men than in women (OR = 2.01, 95% credibility interval: [0.92 to 4.72] and in subjects eating raw vegetables at least once a week than in the others (OR = 8.4, 95% credibility interval: [0.93 to 72.1]. These effects were close to statistical significance. The multivariable analysis highlighted a significant seroprevalence heterogeneity among households. That seroprevalence varied between 6 and 91% (5th and 95th percentile of the household seropositivity distribution. Conclusion The major finding is the household effect, with a strong heterogeneity of seroprevalence among households. This effect may be explained by

Invariant operator theory for the single-photon energy in time-varying media

International Nuclear Information System (INIS)

Jeong-Ryeol, Choi

2010-01-01

After the birth of quantum mechanics, the notion in physics that the frequency of light is the only factor that determines the energy of a single photon has played a fundamental role. However, under the assumption that the theory of Lewis–Riesenfeld invariants is applicable in quantum optics, it is shown in the present work that this widely accepted notion is valid only for light described by a time-independent Hamiltonian, i.e., for light in media satisfying the conditions, ε(i) = ε(0), μ(t) = μ(0), and σ(t) = 0 simultaneously. The use of the Lewis–Riesenfeld invariant operator method in quantum optics leads to a marvelous result: the energy of a single photon propagating through time-varying linear media exhibits nontrivial time dependence without a change of frequency. (general)

Epstein-Barr virus, cytomegalovirus, and multiple sclerosis susceptibility: A multiethnic study.

Science.gov (United States)

Langer-Gould, Annette; Wu, Jun; Lucas, Robyn; Smith, Jessica; Gonzales, Edlin; Amezcua, Lilyana; Haraszti, Samantha; Chen, Lie Hong; Quach, Hong; James, Judith A; Barcellos, Lisa F; Xiang, Anny H

2017-09-26

To determine whether Epstein-Barr virus (EBV) or cytomegalovirus (CMV) seropositivity is associated with multiple sclerosis (MS) in blacks and Hispanics and to what extent measures of the hygiene hypothesis or breastfeeding could explain these findings. EBV and CMV have been associated with MS risk in whites, and the timing and frequency of both viruses vary by factors implicated in the hygiene hypothesis. Incident cases of MS or its precursor, clinically isolated syndrome (CIS), and matched controls (blacks, 111 cases/128 controls; Hispanics, 173/187; whites, 235/256) were recruited from the membership of Kaiser Permanente Southern California. Logistic regression models accounted for HLA-DRB1*1501 status, smoking, socioeconomic status, age, sex, genetic ancestry, and country of birth. Epstein-Barr nuclear antigen-1 (EBNA-1) seropositivity was independently associated with an increased odds of MS/CIS in all 3 racial/ethnic groups ( p < 0.001 for blacks and whites, p = 0.02 for Hispanics). In contrast, CMV seropositivity was associated with a lower risk of MS/CIS in Hispanics ( p = 0.004) but not in blacks ( p = 0.95) or whites ( p = 0.96). Being born in a low/middle-income country was associated with a lower risk of MS in Hispanics ( p = 0.02) but not after accounting for EBNA-1 seropositivity. Accounting for breastfeeding did not diminish the association between CMV and MS in Hispanics. The consistency of EBNA-1 seropositivity with MS across racial/ethnic groups and between studies points to a strong biological link between EBV infection and MS risk. The association between past CMV infection and MS risk supports the broader hygiene hypothesis, but the inconsistency of this association across racial/ethnic groups implies noncausal associations. © 2017 American Academy of Neurology.

High heterogeneity of HIV-related sexual risk among transgender people in Ontario, Canada: a province-wide respondent-driven sampling survey

Directory of Open Access Journals (Sweden)

Bauer Greta R

2012-04-01

Full Text Available Abstract Background Studies of HIV-related risk in trans (transgender, transsexual, or transitioned people have most often involved urban convenience samples of those on the male-to-female (MTF spectrum. Studies have detected high prevalences of HIV-related risk behaviours, self-reported HIV, and HIV seropositivity. Methods The Trans PULSE Project conducted a multi-mode survey using respondent-driven sampling to recruit 433 trans people in Ontario, Canada. Weighted estimates were calculated for HIV-related risk behaviours, HIV testing and self-reported HIV, including subgroup estimates for gender spectrum and ethno-racial groups. Results Trans people in Ontario report a wide range of sexual behaviours with a full range of partner types. High proportions – 25% of female-to-male (FTM and 51% of MTF individuals – had not had a sex partner within the past year. Of MTFs, 19% had a past-year high-risk sexual experience, versus 7% of FTMs. The largest behavioural contributors to HIV risk were sexual behaviours some may assume trans people do not engage in: unprotected receptive genital sex for FTMs and insertive genital sex for MTFs. Overall, 46% had never been tested for HIV; lifetime testing was highest in Aboriginal trans people and lowest among non-Aboriginal racialized people. Approximately 15% of both FTM and MTF participants had engaged in sex work or exchange sex and about 2% currently work in the sex trade. Self-report of HIV prevalence was 10 times the estimated baseline prevalence for Ontario. However, given wide confidence intervals and the high proportion of trans people who had never been tested for HIV, estimating the actual prevalence was not possible. Conclusions Results suggest potentially higher than baseline levels of HIV; however low testing rates were observed and self-reported prevalences likely underestimate seroprevalence. Explicit inclusion of trans people in epidemiological surveillance statistics would provide much

Time-varying Crash Risk

DEFF Research Database (Denmark)

Christoffersen, Peter; Feunoua, Bruno; Jeon, Yoontae

We estimate a continuous-time model with stochastic volatility and dynamic crash probability for the S&P 500 index and find that market illiquidity dominates other factors in explaining the stock market crash risk. While the crash probability is time-varying, its dynamic depends only weakly on re...

Time varying voltage combustion control and diagnostics sensor

Science.gov (United States)

Chorpening, Benjamin T [Morgantown, WV; Thornton, Jimmy D [Morgantown, WV; Huckaby, E David [Morgantown, WV; Fincham, William [Fairmont, WV

2011-04-19

A time-varying voltage is applied to an electrode, or a pair of electrodes, of a sensor installed in a fuel nozzle disposed adjacent the combustion zone of a continuous combustion system, such as of the gas turbine engine type. The time-varying voltage induces a time-varying current in the flame which is measured and used to determine flame capacitance using AC electrical circuit analysis. Flame capacitance is used to accurately determine the position of the flame from the sensor and the fuel/air ratio. The fuel and/or air flow rate (s) is/are then adjusted to provide reduced flame instability problems such as flashback, combustion dynamics and lean blowout, as well as reduced emissions. The time-varying voltage may be an alternating voltage and the time-varying current may be an alternating current.

Detection of dynamically varying interaural time differences

DEFF Research Database (Denmark)

Kohlrausch, Armin; Le Goff, Nicolas; Breebaart, Jeroen

2010-01-01

of fringes surrounding the probe is equal to the addition of the effects of the individual fringes. In this contribution, we present behavioral data for the same experimental condition, called dynamically varying ITD detection, but for a wider range of probe and fringe durations. Probe durations varied...

Central recirculation zone analysis in an unconfined tangential swirl burner with varying degrees of premixing

Energy Technology Data Exchange (ETDEWEB)

Valera-Medina, A. [CIATEQ, Parque Industrial Bernardo Quintana, Turbomachinery Department, Queretaro (Mexico); Syred, N.; Kay, P.; Griffiths, A. [Cardiff University, School of Engineering, Cardiff, Wales (United Kingdom)

2011-06-15

Swirl-stabilised combustion is one of the most widely used techniques for flame stabilisation, uses ranging from gas turbine combustors to pulverised coal-fired power stations. In gas turbines, lean premixed systems are of especial importance, giving the ability to produce low NOx systems coupled with wide stability limits. The common element is the swirl burner, which depends on the generation of an aerodynamically formed central recirculation zone (CRZ) and which serves to recycle heat and active chemical species to the root of the flame as well as providing low-velocity regions where the flame speed can match the local flow velocity. Enhanced mixing in and around the CRZ is another beneficial feature. The structure of the CRZ and hence that of the associated flames, stabilisation and mixing processes have shown to be extremely complex, three-dimensional and time dependent. The characteristics of the CRZ depend very strongly on the level of swirl (swirl number), burner configuration, type of flow expansion, Reynolds number (i.e. flowrate) and equivalence ratio. Although numerical methods have had some success when compared to experimental results, the models still have difficulties at medium to high swirl levels, with complex geometries and varied equivalence ratios. This study thus focuses on experimental results obtained to characterise the CRZ formed under varied combustion conditions with different geometries and some variation of swirl number in a generic swirl burner. CRZ behaviour has similarities to the equivalent isothermal state, but is strongly dependent on equivalence ratio, with interesting effects occurring with a high-velocity fuel injector. Partial premixing and combustion cause more substantive changes to the CRZ than pure diffusive combustion. (orig.)

Genetic association study of NLRP1, CARD, and CASP1 inflammasome genes with chronic Chagas cardiomyopathy among Trypanosoma cruzi seropositive patients in Bolivia.

Science.gov (United States)

Clipman, Steven J; Henderson-Frost, Josephine; Fu, Katherine Y; Bern, Caryn; Flores, Jorge; Gilman, Robert H

2018-01-01

About 20-30% of people infected with Chagas disease present with chronic Chagas cardiomyopathy (CCC), the most serious and frequent manifestation of the disease, while others remain asymptomatic and often do not experience Chagas-specific mortality. It is not currently well understood what causes these differential disease outcomes, but a genetic predisposition within the host could play an important role. This study examined variants in the NLRP1, CARD, and CASP1 inflammasome genes among 62 T. cruzi seropositive patients from Bolivia (38 cases with CCC and 24 asymptomatic controls) to uncover associations with CCC. All subjects underwent a complete medical examination including electrocardiogram (EKG) and echocardiogram. After genotype calling and quality control filtering with exclusion of 3 cases and 3 controls, association analysis was performed across 76 directly genotyped SNPs in NLRP1, CARD, and CASP1 genes, adjusting for age, sex, and population stratification. One SNP (rs11651270; Bonferroni-corrected p = 0.036) corresponding to a missense mutation in NLPR1 was found to be significant after adjustment for multiple testing, and a suggestive association was seen in CARD11 (rs6953573; Bonferroni-corrected p = 0.060). Although limited by sample size, the study results suggest variations in the inflammasome, particularly in NLRP1 and CARD11, may be associated with CCC.

Limiting photocurrent analysis of a wide channel photoelectrochemical flow reactor

International Nuclear Information System (INIS)

Davis, Jonathan T; Esposito, Daniel V

2017-01-01

The development of efficient and scalable photoelectrochemical (PEC) reactors is of great importance for the eventual commercialization of solar fuels technology. In this study, we systematically explore the influence of convective mass transport and light intensity on the performance of a 3D-printed PEC flow cell reactor based on a wide channel, parallel plate geometry. Using this design, the limiting current density generated from the hydrogen evolution reaction at a p-Si metal–insulator–semiconductor (MIS) photocathode was investigated under varied reactant concentration, fluid velocity, and light intensity. Additionally, a simple model is introduced to predict the range of operating conditions (reactant concentration, light intensity, fluid velocity) for which the photocurrent generated in a parallel plate PEC flow cell is limited by light absorption or mass transport. This model can serve as a useful guide for the design and operation of wide-channel PEC flow reactors. The results of this study have important implications for PEC reactors operating in electrolytes with dilute reactant concentrations and/or under high light intensities where high fluid velocities are required in order to avoid operation in the mass transport-limited regime. (paper)

Estimating varying coefficients for partial differential equation models.

Science.gov (United States)

Zhang, Xinyu; Cao, Jiguo; Carroll, Raymond J

2017-09-01

Partial differential equations (PDEs) are used to model complex dynamical systems in multiple dimensions, and their parameters often have important scientific interpretations. In some applications, PDE parameters are not constant but can change depending on the values of covariates, a feature that we call varying coefficients. We propose a parameter cascading method to estimate varying coefficients in PDE models from noisy data. Our estimates of the varying coefficients are shown to be consistent and asymptotically normally distributed. The performance of our method is evaluated by a simulation study and by an empirical study estimating three varying coefficients in a PDE model arising from LIDAR data. © 2017, The International Biometric Society.

A solution to the varying response of the linear power monitor induced by xenon poisoning

Energy Technology Data Exchange (ETDEWEB)

Godsey, T A; Randall, J D [Texas A and M University (United States)

1974-07-01

After conversion to FLIP fuel at Texas A and M, the fuel temperatures were examined very carefully. It was observed that the fuel temperature at 1 Mw varied over a wide range during the week. This variation was shown to be due to the variation in response of the linear CIC which was used to establish reactor power level. A modification of the linear power monitor was designed and installed. The response of this system was verified by using cobalt wires, fuel temperature, and a fission chamber located at 6 feet from the reactor core. The system has proven to be operationally satisfactory. (author)

Time-Varying Distortions of Binaural Information by Bilateral Hearing Aids

Science.gov (United States)

Rodriguez, Francisco A.; Portnuff, Cory D. F.; Goupell, Matthew J.; Tollin, Daniel J.

2016-01-01

In patients with bilateral hearing loss, the use of two hearing aids (HAs) offers the potential to restore the benefits of binaural hearing, including sound source localization and segregation. However, existing evidence suggests that bilateral HA users’ access to binaural information, namely interaural time and level differences (ITDs and ILDs), can be compromised by device processing. Our objective was to characterize the nature and magnitude of binaural distortions caused by modern digital behind-the-ear HAs using a variety of stimuli and HA program settings. Of particular interest was a common frequency-lowering algorithm known as nonlinear frequency compression, which has not previously been assessed for its effects on binaural information. A binaural beamforming algorithm was also assessed. Wide dynamic range compression was enabled in all programs. HAs were placed on a binaural manikin, and stimuli were presented from an arc of loudspeakers inside an anechoic chamber. Stimuli were broadband noise bursts, 10-Hz sinusoidally amplitude-modulated noise bursts, or consonant–vowel–consonant speech tokens. Binaural information was analyzed in terms of ITDs, ILDs, and interaural coherence, both for whole stimuli and in a time-varying sense (i.e., within a running temporal window) across four different frequency bands (1, 2, 4, and 6 kHz). Key findings were: (a) Nonlinear frequency compression caused distortions of high-frequency envelope ITDs and significantly reduced interaural coherence. (b) For modulated stimuli, all programs caused time-varying distortion of ILDs. (c) HAs altered the relationship between ITDs and ILDs, introducing large ITD–ILD conflicts in some cases. Potential perceptual consequences of measured distortions are discussed. PMID:27698258

New varying speed of light theories

CERN Document Server

Magueijo, J

2003-01-01

We review recent work on the possibility of a varying speed of light (VSL). We start by discussing the physical meaning of a varying $c$, dispelling the myth that the constancy of $c$ is a matter of logical consistency. We then summarize the main VSL mechanisms proposed so far: hard breaking of Lorentz invariance; bimetric theories (where the speeds of gravity and light are not the same); locally Lorentz invariant VSL theories; theories exhibiting a color dependent speed of light; varying $c$ induced by extra dimensions (e.g. in the brane-world scenario); and field theories where VSL results from vacuum polarization or CPT violation. We show how VSL scenarios may solve the cosmological problems usually tackled by inflation, and also how they may produce a scale-invariant spectrum of Gaussian fluctuations, capable of explaining the WMAP data. We then review the connection between VSL and theories of quantum gravity, showing how ``doubly special'' relativity has emerged as a VSL effective model of quantum space...

Complexity Variability Assessment of Nonlinear Time-Varying Cardiovascular Control

Science.gov (United States)

Valenza, Gaetano; Citi, Luca; Garcia, Ronald G.; Taylor, Jessica Noggle; Toschi, Nicola; Barbieri, Riccardo

2017-02-01

The application of complex systems theory to physiology and medicine has provided meaningful information about the nonlinear aspects underlying the dynamics of a wide range of biological processes and their disease-related aberrations. However, no studies have investigated whether meaningful information can be extracted by quantifying second-order moments of time-varying cardiovascular complexity. To this extent, we introduce a novel mathematical framework termed complexity variability, in which the variance of instantaneous Lyapunov spectra estimated over time serves as a reference quantifier. We apply the proposed methodology to four exemplary studies involving disorders which stem from cardiology, neurology and psychiatry: Congestive Heart Failure (CHF), Major Depression Disorder (MDD), Parkinson’s Disease (PD), and Post-Traumatic Stress Disorder (PTSD) patients with insomnia under a yoga training regime. We show that complexity assessments derived from simple time-averaging are not able to discern pathology-related changes in autonomic control, and we demonstrate that between-group differences in measures of complexity variability are consistent across pathologies. Pathological states such as CHF, MDD, and PD are associated with an increased complexity variability when compared to healthy controls, whereas wellbeing derived from yoga in PTSD is associated with lower time-variance of complexity.

Initial locomotor sensitivity to cocaine varies widely among inbred mouse strains.

Science.gov (United States)

Wiltshire, T; Ervin, R B; Duan, H; Bogue, M A; Zamboni, W C; Cook, S; Chung, W; Zou, F; Tarantino, L M

2015-03-01

Initial sensitivity to psychostimulants can predict subsequent use and abuse in humans. Acute locomotor activation in response to psychostimulants is commonly used as an animal model of initial drug sensitivity and has been shown to have a substantial genetic component. Identifying the specific genetic differences that lead to phenotypic differences in initial drug sensitivity can advance our understanding of the processes that lead to addiction. Phenotyping inbred mouse strain panels are frequently used as a first step for studying the genetic architecture of complex traits. We assessed locomotor activation following a single, acute 20 mg/kg dose of cocaine (COC) in males from 45 inbred mouse strains and observed significant phenotypic variation across strains indicating a substantial genetic component. We also measured levels of COC, the active metabolite, norcocaine and the major inactive metabolite, benzoylecgonine, in plasma and brain in the same set of inbred strains. Pharmacokinetic (PK) and behavioral data were significantly correlated, but at a level that indicates that PK alone does not account for the behavioral differences observed across strains. Phenotypic data from this reference population of inbred strains can be utilized in studies aimed at examining the role of psychostimulant-induced locomotor activation on drug reward and reinforcement and to test theories about addiction processes. Moreover, these data serve as a starting point for identifying genes that alter sensitivity to the locomotor stimulatory effects of COC. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Many Options in New Orleans Choice System: School Characteristics Vary Widely

Science.gov (United States)

Arce-­Trigatti, Paula; Harris, Douglas N.; Jabbar, Huriya; Lincove, Jane Arnold

2015-01-01

Previous studies have focused on the differences between charter schools and district schools, treating all charters within a community as essentially alike. In effect, these studies take a "top­-down" approach, assuming that the governance of the school (charter versus district) determines the nature of the school. This approach may be…

Kidney Disease in Human Immunodeficiency Virus-seropositive Patients: Absence of Human Immunodeficiency Virus-associated Nephropathy was a Characteristic Feature.

Science.gov (United States)

Prakash, J; Ganiger, V; Prakash, S; Sivasankar, M; Sunder, S; Singh, U

2017-01-01

Human immunodeficiency virus (HIV) infection can cause a broad spectrum of renal diseases. However, there is paucity of Indian data on the patterns of renal lesions in HIV-seropositive patients. The aim of the present study was to delineate the spectrum of renal lesions in HIV/acquired immunodeficiency syndrome patients. In this prospective study, all HIV-positive patients of both genders aged >18 years were screened for renal disease. Patients with proteinuria of more than 1 g/24 h were subjected to renal biopsy. A total of 293 HIV-positive patients were screened; of these, 136 (46.4%) patients found to have renal involvement. Dipstick-positive proteinuria of 1+ or more was observed in 112 (38.2%) patients, and 16 (14.2%) patients had proteinuria of more than 1 g/24 h. Renal biopsy in 14 cases revealed glomerulonephritis (GN) in 12 (85.7%) (isolated GN in 4 [28.5%] and GN mixed with chronic TIN in 8 [57.1%]) patients. These include mesangioproliferative GN in 5 (35.7%), membranoproliferative GN in 2 (14.2%), focal segmental glomerulosclerosis in 2 (14.2%), diffuse proliferative GN in 2 (14.2%), and diabetic nephropathy in 1 (7.1%) patients. Chronic interstitial nephritis was noted in 10 (71.42%) (superimposed on GN in 8 [57.1%], isolated in 2 [14.2%]) patients. Granulomatous interstitial nephritis was seen in 3 (24.1%) cases. GN and chronic interstitial nephritis were noted in 85.7% and 71.42% of patients, respectively, mostly superimposed on each other. Mesangioproliferative GN was the most common glomerular lesion, but classical HIV-associated nephropathy was not observed.

DNA restriction fragment length polymorphism analysis of Mycobacterium tuberculosis isolates from HIV-seropositive and HIV-seronegative patients in Kampala, Uganda

Directory of Open Access Journals (Sweden)

Katabazi Fred A

2009-02-01

Full Text Available Abstract Background The identification and differentiation of strains of Mycobacterium tuberculosis by DNA fingerprinting has provided a better understanding of the epidemiology and tracing the transmission of tuberculosis. We set out to determine if there was a relationship between the risk of belonging to a group of tuberculosis patients with identical mycobacterial DNA fingerprint patterns and the HIV sero-status of the individuals in a high TB incidence peri-urban setting of Kampala, Uganda. Methods One hundred eighty three isolates of Mycobacterium tuberculosis from 80 HIV seropositive and 103 HIV seronegative patients were fingerprinted by standard IS6110-RFLP. Using the BioNumerics software, strains were considered to be clustered if at least one other patient had an isolate with identical RFLP pattern. Results One hundred and eighteen different fingerprint patterns were obtained from the 183 isolates. There were 34 clusters containing 54% (99/183 of the patients (average cluster size of 2.9, and a majority (96.2% of the strains possessed a high copy number (≥ 5 copies of the IS6110 element. When strains with P = 0.615, patients aged P = 0.100, and sex (aOR 1.12, 95%CI 0.60–2.06, P = 0.715. Conclusion The sample showed evidence of a high prevalence of recent transmission with a high average cluster size, but infection with an isolate with a fingerprint found to be part of a cluster was not associated with any demographic or clinical characteristics, including HIV status.

Spatially varying selection shapes life history clines among populations of Drosophila melanogaster from sub-Saharan Africa.

Science.gov (United States)

Fabian, D K; Lack, J B; Mathur, V; Schlötterer, C; Schmidt, P S; Pool, J E; Flatt, T

2015-04-01

Clines in life history traits, presumably driven by spatially varying selection, are widespread. Major latitudinal clines have been observed, for example, in Drosophila melanogaster, an ancestrally tropical insect from Africa that has colonized temperate habitats on multiple continents. Yet, how geographic factors other than latitude, such as altitude or longitude, affect life history in this species remains poorly understood. Moreover, most previous work has been performed on derived European, American and Australian populations, but whether life history also varies predictably with geography in the ancestral Afro-tropical range has not been investigated systematically. Here, we have examined life history variation among populations of D. melanogaster from sub-Saharan Africa. Viability and reproductive diapause did not vary with geography, but body size increased with altitude, latitude and longitude. Early fecundity covaried positively with altitude and latitude, whereas lifespan showed the opposite trend. Examination of genetic variance-covariance matrices revealed geographic differentiation also in trade-off structure, and QST -FST analysis showed that life history differentiation among populations is likely shaped by selection. Together, our results suggest that geographic and/or climatic factors drive adaptive phenotypic differentiation among ancestral African populations and confirm the widely held notion that latitude and altitude represent parallel gradients. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Varying constants, black holes, and quantum gravity

International Nuclear Information System (INIS)

Carlip, S.

2003-01-01

Tentative observations and theoretical considerations have recently led to renewed interest in models of fundamental physics in which certain 'constants' vary in time. Assuming fixed black hole mass and the standard form of the Bekenstein-Hawking entropy, Davies, Davis and Lineweaver have argued that the laws of black hole thermodynamics disfavor models in which the fundamental electric charge e changes. I show that with these assumptions, similar considerations severely constrain 'varying speed of light' models, unless we are prepared to abandon cherished assumptions about quantum gravity. Relaxation of these assumptions permits sensible theories of quantum gravity with ''varying constants,'' but also eliminates the thermodynamic constraints, though the black hole mass spectrum may still provide some restrictions on the range of allowable models

A topological approach to migration and visualization of time-varying volume data

International Nuclear Information System (INIS)

Fujishiro, Issei; Otsuka, Rieko; Hamaoka, Aya; Takeshima, Yuriko; Takahashi, Shigeo

2004-01-01

Rapid advance in high performance computing and measurement technologies has recently made it possible to produce a stupendous amount of time-varying volume datasets in various disciplines. However, there exist a few known visual exploration tools which allow us to investigate the core of their complex behavior effectively. In this article, our previous approach to topological volume skeletonization is extended to capture the topological skeleton of a 4D volumetric field in terms of critical timing. A cyclic information drilldown scheme, termed T-map, is presented, where a wide choice of information visualization techniques are deployed so that the users are allowed to repeatedly squeeze partial spatiotemporal domains of interest until the size gets fitted into an available computing storage space, prior to topologically-accentuated visualization of the pinpointed volumetric domains. A case study with datasets from atomic collision research is performed to illustrate the feasibility of the present method. (author)

Error Analysis for RADAR Neighbor Matching Localization in Linear Logarithmic Strength Varying Wi-Fi Environment

Directory of Open Access Journals (Sweden)

Mu Zhou

2014-01-01

Full Text Available This paper studies the statistical errors for the fingerprint-based RADAR neighbor matching localization with the linearly calibrated reference points (RPs in logarithmic received signal strength (RSS varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs. However, in order to achieve the efficient and reliable location-based services (LBSs as well as the ubiquitous context-awareness in Wi-Fi environment, much attention has to be paid to the highly accurate and cost-efficient localization systems. To this end, the statistical errors by the widely used neighbor matching localization are significantly discussed in this paper to examine the inherent mathematical relations between the localization errors and the locations of RPs by using a basic linear logarithmic strength varying model. Furthermore, based on the mathematical demonstrations and some testing results, the closed-form solutions to the statistical errors by RADAR neighbor matching localization can be an effective tool to explore alternative deployment of fingerprint-based neighbor matching localization systems in the future.

Error Analysis for RADAR Neighbor Matching Localization in Linear Logarithmic Strength Varying Wi-Fi Environment

Science.gov (United States)

Tian, Zengshan; Xu, Kunjie; Yu, Xiang

2014-01-01

This paper studies the statistical errors for the fingerprint-based RADAR neighbor matching localization with the linearly calibrated reference points (RPs) in logarithmic received signal strength (RSS) varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs. However, in order to achieve the efficient and reliable location-based services (LBSs) as well as the ubiquitous context-awareness in Wi-Fi environment, much attention has to be paid to the highly accurate and cost-efficient localization systems. To this end, the statistical errors by the widely used neighbor matching localization are significantly discussed in this paper to examine the inherent mathematical relations between the localization errors and the locations of RPs by using a basic linear logarithmic strength varying model. Furthermore, based on the mathematical demonstrations and some testing results, the closed-form solutions to the statistical errors by RADAR neighbor matching localization can be an effective tool to explore alternative deployment of fingerprint-based neighbor matching localization systems in the future. PMID:24683349

The structure of a three-dimensional boundary layer subjected to streamwise-varying spanwise-homogeneous pressure gradient

International Nuclear Information System (INIS)

Bentaleb, Y.; Leschziner, M.A.

2013-01-01

Highlights: • We study a spatially-evolving three-dimensional boundary layer. • We impose a streamwise-varying spanwise-homogeneous pressure gradient. • A collateral flow is formed close to the wall, and this is investigated alongside the skewed upper part of the boundary layer. • A wide range of flow-physical properties have been studied. -- Abstract: A spatially-evolving three-dimensional boundary layer, subjected to a streamwise-varying spanwise-homogeneous pressure gradient, equivalent to a body force, is investigated by way of direct numerical simulation. The pressure gradient, prescribed to change its sign half-way along the boundary layer, provokes strong skewing of the velocity vector, with a layer of nearly collateral flow forming close to the wall up to the position of maximum spanwise velocity. A wide range of flow-physical properties have been studied, with particular emphasis on the near-wall layer, including second-moments, major budget contributions and wall-normal two-point correlations of velocity fluctuations and their angles, relative to wall-shear fluctuations. The results illustrate the complexity caused by skewing, including a damping in turbulent mixing and a significant lag between strains and stresses. The study has been undertaken in the context of efforts to develop and test novel hybrid LES–RANS schemes for non-equilibrium near-wall flows, with an emphasis on three-dimensional near-wall straining. Fundamental flow-physical issues aside, the data derived should be of particular relevance to a priori studies of second-moment RANS closure and the development and validation of RANS-type near-wall approximations implemented in LES schemes for high-Reynolds-number complex flows

Wide-Gap Chalcopyrites

CERN Document Server

Siebentritt, Susanne

2006-01-01

Chalcopyrites, in particular those with a wide band gap, are fascinating materials in terms of their technological potential in the next generation of thin-film solar cells and in terms of their basic material properties. They exhibit uniquely low defect formation energies, leading to unusual doping and phase behavior and to extremely benign grain boundaries. This book collects articles on a number of those basic material properties of wide-gap chalcopyrites, comparing them to their low-gap cousins. They explore the doping of the materials, the electronic structure and the transport through interfaces and grain boundaries, the formation of the electric field in a solar cell, the mechanisms and suppression of recombination, the role of inhomogeneities, and the technological role of wide-gap chalcopyrites.

Mediation analysis with time varying exposures and mediators.

Science.gov (United States)

VanderWeele, Tyler J; Tchetgen Tchetgen, Eric J

2017-06-01

In this paper we consider causal mediation analysis when exposures and mediators vary over time. We give non-parametric identification results, discuss parametric implementation, and also provide a weighting approach to direct and indirect effects based on combining the results of two marginal structural models. We also discuss how our results give rise to a causal interpretation of the effect estimates produced from longitudinal structural equation models. When there are time-varying confounders affected by prior exposure and mediator, natural direct and indirect effects are not identified. However, we define a randomized interventional analogue of natural direct and indirect effects that are identified in this setting. The formula that identifies these effects we refer to as the "mediational g-formula." When there is no mediation, the mediational g-formula reduces to Robins' regular g-formula for longitudinal data. When there are no time-varying confounders affected by prior exposure and mediator values, then the mediational g-formula reduces to a longitudinal version of Pearl's mediation formula. However, the mediational g-formula itself can accommodate both mediation and time-varying confounders and constitutes a general approach to mediation analysis with time-varying exposures and mediators.

The focusing effect of electromagnetic waves in two-dimensional photonic crystals with gradually varying lattice constant

Directory of Open Access Journals (Sweden)

F Bakhshi Garmi

2016-02-01

Full Text Available In this paper we studied the focusing effect of electromagnetic wave in the two-dimensional graded photonic crystal consisting of Silicon rods in the air background with gradually varying lattice constant. The results showed that graded photonic crystal can focus wide beams on a narrow area at frequencies near the lower edge of the band gap, where equal frequency contours are not concave. For calculation of photonic band structure and equal frequency contours, we have used plane wave expansion method and revised plane wave expansion method, respectively. The calculation of the electric and magnetic fields was performed by finite difference time domain method.

Summary of the U.S. specimen matrix for the HFIR 13J varying temperature irradiation capsule

International Nuclear Information System (INIS)

Zinkle, S.J.

1998-01-01

The US specimen matrix for the collaborative DOE/Monbusho HFIR 13J varying temperature irradiation capsule contains two ceramics and 29 different metals, including vanadium alloys, ferritic/martensitic steels, pure iron, austenitic stainless steels, nickel alloys, and copper alloys. This experiment is designed to provide fundamental information on the effects of brief low-temperature excursions on the tensile properties and microstructural evolution of a wide range of materials irradiated at nominal temperatures of 350 and 500 C to a dose of ∼5 dpa. A total of 340 miniature sheet tensile specimens and 274 TEM disks are included in the US-supplied matrix for the irradiation capsule

Eestlased Karlovy Varys / J. R.

Index Scriptorium Estoniae

J. R.

2007-01-01

Ilmar Raagi mängufilm "Klass" osaleb 42. Karlovy Vary rahvusvahelise filmifestivali võistlusprogrammis "East of the West" ja Asko Kase lühimängufilm "Zen läbi prügi" on valitud festivali kõrvalprogrammi "Forum of Independents"

SHOK—The First Russian Wide-Field Optical Camera in Space

Science.gov (United States)

Lipunov, V. M.; Gorbovskoy, E. S.; Kornilov, V. G.; Panasyuk, M. I.; Amelushkin, A. M.; Petrov, V. L.; Yashin, I. V.; Svertilov, S. I.; Vedenkin, N. N.

2018-02-01

Onboard the spacecraft Lomonosov is established two fast, fixed, very wide-field cameras SHOK. The main goal of this experiment is the observation of GRB optical emission before, synchronously, and after the gamma-ray emission. The field of view of each of the cameras is placed in the gamma-ray burst detection area of other devices located onboard the "Lomonosov" spacecraft. SHOK provides measurements of optical emissions with a magnitude limit of ˜ 9-10m on a single frame with an exposure of 0.2 seconds. The device is designed for continuous sky monitoring at optical wavelengths in the very wide field of view (1000 square degrees each camera), detection and localization of fast time-varying (transient) optical sources on the celestial sphere, including provisional and synchronous time recording of optical emissions from the gamma-ray burst error boxes, detected by the BDRG device and implemented by a control signal (alert trigger) from the BDRG. The Lomonosov spacecraft has two identical devices, SHOK1 and SHOK2. The core of each SHOK device is a fast-speed 11-Megapixel CCD. Each of the SHOK devices represents a monoblock, consisting of a node observations of optical emission, the electronics node, elements of the mechanical construction, and the body.

Comparison of Linear Microinstability Calculations of Varying Input Realism

International Nuclear Information System (INIS)

Rewoldt, G.

2003-01-01

The effect of varying ''input realism'' or varying completeness of the input data for linear microinstability calculations, in particular on the critical value of the ion temperature gradient for the ion temperature gradient mode, is investigated using gyrokinetic and gyrofluid approaches. The calculations show that varying input realism can have a substantial quantitative effect on the results

Comparison of linear microinstability calculations of varying input realism

International Nuclear Information System (INIS)

Rewoldt, G.; Kinsey, J.E.

2004-01-01

The effect of varying 'input realism' or varying completeness of the input data for linear microinstability calculations, in particular on the critical value of the ion temperature gradient for the ion temperature gradient mode, is investigated using gyrokinetic and gyrofluid approaches. The calculations show that varying input realism can have a substantial quantitative effect on the results

Marketingový mix HC Enegie Karlovy Vary

OpenAIRE

Štrobl, Adam

2016-01-01

Title: Marketing mix of HC Energie Karlovy Vary Objectives: This thesis is based on a questionnaire responses obtained from HC Energie Karlovy Vary fans. Its objective is focused on evaluation of their opinions on the marketing mix, their subsequent interpretation, and finally even development of recommendations for improvement based on previous analysis. Methods: Two methods are used to analyse the marketing mix. The first method is qualitative participant observation. The second method is a...

Õunpuu Karlovy Varys edukas

Index Scriptorium Estoniae

2010-01-01

45. Karlovy Vary filmifestivali võistlusprogrammis "East of the West" märgiti ära Veiko Õunpuu film "Püha Tõnu kiusamine". Peaauhind läks rumeenlase Cristi Puiu filmile "Aurora". Grand prix´sai Augustĺ Vila film "La mosquitera". Teisi preemiasaajaid

Design and implementation of multi-signal and time-varying neural reconstructions.

Science.gov (United States)

Nanda, Sumit; Chen, Hanbo; Das, Ravi; Bhattacharjee, Shatabdi; Cuntz, Hermann; Torben-Nielsen, Benjamin; Peng, Hanchuan; Cox, Daniel N; De Schutter, Erik; Ascoli, Giorgio A

2018-01-23

Several efficient procedures exist to digitally trace neuronal structure from light microscopy, and mature community resources have emerged to store, share, and analyze these datasets. In contrast, the quantification of intracellular distributions and morphological dynamics is not yet standardized. Current widespread descriptions of neuron morphology are static and inadequate for subcellular characterizations. We introduce a new file format to represent multichannel information as well as an open-source Vaa3D plugin to acquire this type of data. Next we define a novel data structure to capture morphological dynamics, and demonstrate its application to different time-lapse experiments. Importantly, we designed both innovations as judicious extensions of the classic SWC format, thus ensuring full back-compatibility with popular visualization and modeling tools. We then deploy the combined multichannel/time-varying reconstruction system on developing neurons in live Drosophila larvae by digitally tracing fluorescently labeled cytoskeletal components along with overall dendritic morphology as they changed over time. This same design is also suitable for quantifying dendritic calcium dynamics and tracking arbor-wide movement of any subcellular substrate of interest.

Using latent variable approach to estimate China's economy-wide energy rebound effect over 1954–2010

International Nuclear Information System (INIS)

Shao, Shuai; Huang, Tao; Yang, Lili

2014-01-01

The energy rebound effect has been a significant issue in China, which is undergoing economic transition, since it reflects the effectiveness of energy-saving policy relying on improved energy efficiency. Based on the IPAT equation and Brookes' explanation of the rebound effect, this paper develops an alternative estimation model of the rebound effect. By using the estimation model and latent variable approach, which is achieved through a time-varying coefficient state space model, we estimate China's economy-wide energy rebound effect over 1954–2010. The results show that the rebound effect evidently exists in China as a result of the annual average of 39.73% over 1954–2010. Before and after the implementation of China's reform and opening-up policy in 1978, the rebound effects are 47.24% and 37.32%, with a strong fluctuation and a circuitously downward trend, respectively, indicating that a stable political environment and the development of market economy system facilitate the effectiveness of energy-saving policy. Although the energy-saving effect of improving energy efficiency has been partly realised, there remains a large energy-saving potential in China. - Highlights: • We present an improved estimation methodology of economy-wide energy rebound effect. • We use the latent variable approach to estimate China's economy-wide rebound effect. • The rebound exists in China and varies before and after reform and opening-up. • After 1978, the average rebound is 37.32% with a circuitously downward trend. • Traditional Solow remainder method underestimates the rebound in most cases

Optimistlik Karlovy Vary / Jaan Ruus

Index Scriptorium Estoniae

Ruus, Jaan, 1938-2017

2007-01-01

42. Karlovy Vary rahvusvahelise filmifestivali auhinnatud filmidest (žürii esimees Peter Bart). Kristallgloobuse sai Islandi-Saksamaa "Katseklaasilinn" (režii Baltasar Kormakur), parimaks režissööriks tunnistati norralane Bard Breien ("Negatiivse mõtlemise kunst"). Austraallase Michael James Rowlandi "Hea õnne teekond" sai žürii eripreemia

A Design of Wide Band and Wide Beam Cavity-Backed Slot Antenna Array with Slant Polarization

Directory of Open Access Journals (Sweden)

Huiying Qi

2016-01-01

Full Text Available Design of antenna array under the limitation of restricted size is a challenging problem. Cavity-backed slot antenna is widely used because of its advantages of small size, wide band, and wide beam. In this paper, a design of wide band and wide beam cavity-backed slot antenna array with the slant polarization is proposed. To obtain wide band and wide beam with limited size, the inverted microstrip-fed cavity-backed slot antenna (IMF-CBSA is adopted as the element of 1 × 4 antenna array. The slant polarized antennas and their feeding networks are adopted because of their simple structures. The performance of the proposed antenna array is verified by the simulations and experiments. The measured VSWR < 2 bandwidth is 55% at the center frequency 21.8 GHz, and the gain is larger than 12.2 dB. Experimental results demonstrate that the proposed design achieves wide band and beam with the size of 68 mm × 56 mm × 14.5 mm.

Time-varying value of electric energy efficiency

Energy Technology Data Exchange (ETDEWEB)

Mims, Natalie A.; Eckman, Tom; Goldman, Charles

2017-06-30

Electric energy efficiency resources save energy and may reduce peak demand. Historically, quantification of energy efficiency benefits has largely focused on the economic value of energy savings during the first year and lifetime of the installed measures. Due in part to the lack of publicly available research on end-use load shapes (i.e., the hourly or seasonal timing of electricity savings) and energy savings shapes, consideration of the impact of energy efficiency on peak demand reduction (i.e., capacity savings) has been more limited. End-use load research and the hourly valuation of efficiency savings are used for a variety of electricity planning functions, including load forecasting, demand-side management and evaluation, capacity and demand response planning, long-term resource planning, renewable energy integration, assessing potential grid modernization investments, establishing rates and pricing, and customer service. This study reviews existing literature on the time-varying value of energy efficiency savings, provides examples in four geographically diverse locations of how consideration of the time-varying value of efficiency savings impacts the calculation of power system benefits, and identifies future research needs to enhance the consideration of the time-varying value of energy efficiency in cost-effectiveness screening analysis. Findings from this study include: -The time-varying value of individual energy efficiency measures varies across the locations studied because of the physical and operational characteristics of the individual utility system (e.g., summer or winter peaking, load factor, reserve margin) as well as the time periods during which savings from measures occur. -Across the four locations studied, some of the largest capacity benefits from energy efficiency are derived from the deferral of transmission and distribution system infrastructure upgrades. However, the deferred cost of such upgrades also exhibited the greatest range

Re-identification of persons in multi-camera surveillance under varying viewpoints and illumination

Science.gov (United States)

Bouma, Henri; Borsboom, Sander; den Hollander, Richard J. M.; Landsmeer, Sander H.; Worring, Marcel

2012-06-01

The capability to track individuals in CCTV cameras is important for surveillance and forensics alike. However, it is laborious to do over multiple cameras. Therefore, an automated system is desirable. In literature several methods have been proposed, but their robustness against varying viewpoints and illumination is limited. Hence performance in realistic settings is also limited. In this paper, we present a novel method for the automatic re-identification of persons in video from surveillance cameras in a realistic setting. The method is computationally efficient, robust to a wide variety of viewpoints and illumination, simple to implement and it requires no training. We compare the performance of our method to several state-of-the-art methods on a publically available dataset that contains the variety of viewpoints and illumination to allow benchmarking. The results indicate that our method shows good performance and enables a human operator to track persons five times faster.

Experimental evidence for amplitude death induced by a time-varying interaction

Energy Technology Data Exchange (ETDEWEB)

Suresh, K. [Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India); Shrimali, M.D. [Department of Physics, Central University of Rajasthan, NH-8, Bandar Sindri, Ajmer 305 801 (India); Prasad, Awadhesh [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India); Thamilmaran, K., E-mail: maran.cnld@gmail.com [Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India)

2014-08-01

In this paper, we study the time-varying interaction in coupled oscillatory systems. For this purpose, we have designed a novel time-varying resistive network using an analog switch and inverter circuits. We have applied this time-varying resistive network to mutually coupled identical Chua's oscillators. When the resistances are varied in time, we find that amplitude death arises in coupled identical oscillators. This has been observed numerically as well as verified through hardware experiments. - Highlights: • We have implemented the time-varying interaction in coupled oscillatory systems. • We have designed a novel time-varying resistive network using an analog switch and inverter circuits. • When the resistances are varied in time, we find that amplitude death arises in coupled identical oscillators.

Brane world cosmologies with varying speed of light

International Nuclear Information System (INIS)

Youm, Donam

2001-02-01

We study cosmologies in the Randall-Sundrum models, incorporating the possibility of time-varying speed of light and Newton's constant. The cosmologies with varying speed of light (VSL) were proposed by Moffat and by Albrecht and Magueijo as an alternative to inflation for solving the cosmological problems. We consider the case in which the speed of light varies with time after the radion or the scale of the extra dimension has been stabilized. We elaborate on the conditions under which the flatness problem and the cosmological constant problem can be resolved. Particularly, the VSL cosmologies may provide a possible mechanism for bringing the quantum corrections to the fine-tuned brane tensions after the SUSY breaking under control. (author)

Disruption of soil aggregates by varied amounts of ultrasonic energy in fractionation of organic matter of a clay latosol : carbon, nitrogen and 13C distribution in particle-size fractions

NARCIS (Netherlands)

Roscoe, R.; Buurman, P.; Velthorst, E.J.

2000-01-01

Ultrasonic energy has been widely used to disrupt soil aggregates before fractionating soil physically when studying soil organic matter (SOM). Nevertheless, there is no consensus about the optimum energy desirable to disrupt the soil. We therefore aimed (i) to quantify the effect of varied

Generalization of the Wide-Sense Markov Concept to a Widely Linear Processing

International Nuclear Information System (INIS)

Espinosa-Pulido, Juan Antonio; Navarro-Moreno, Jesús; Fernández-Alcalá, Rosa María; Ruiz-Molina, Juan Carlos; Oya-Lechuga, Antonia; Ruiz-Fuentes, Nuria

2014-01-01

In this paper we show that the classical definition and the associated characterizations of wide-sense Markov (WSM) signals are not valid for improper complex signals. For that, we propose an extension of the concept of WSM to a widely linear (WL) setting and the study of new characterizations. Specifically, we introduce a new class of signals, called widely linear Markov (WLM) signals, and we analyze some of their properties based either on second-order properties or on state-space models from a WL processing standpoint. The study is performed in both the forwards and backwards directions of time. Thus, we provide two forwards and backwards Markovian representations for WLM signals. Finally, different estimation recursive algorithms are obtained for these models

Tracking time-varying coefficient-functions

DEFF Research Database (Denmark)

Nielsen, Henrik Aalborg; Nielsen, Torben Skov; Joensen, Alfred K.

2000-01-01

is a combination of recursive least squares with exponential forgetting and local polynomial regression. It is argued, that it is appropriate to let the forgetting factor vary with the value of the external signal which is the argument of the coefficient functions. Some of the key properties of the modified method...... are studied by simulation...

Esmaklassiline Karlovy Vary / Jaanus Noormets

Index Scriptorium Estoniae

Noormets, Jaanus

2007-01-01

Ilmar Raagi mängufilm "Klass" võitis 42. Karlovy Vary rahvusvahelise filmifestivalil kaks auhinda - ametliku kõrvalvõistlusprogrammi "East of the West" eripreemia "Special mention" ja Euroopa väärtfilmikinode keti Europa Cinemas preemia. Ka Asko Kase lühifilmi "Zen läbi prügi linastumisest ning teistest auhinnasaajatest ning osalejatest

Anistropically varying conductivity in irreversible electroporation simulations.

Science.gov (United States)

Labarbera, Nicholas; Drapaca, Corina

2017-11-01

One recent area of cancer research is irreversible electroporation (IRE). Irreversible electroporation is a minimally invasive procedure where needle electrodes are inserted into the body to ablate tumor cells with electricity. The aim of this paper is to propose a mathematical model that incorporates a tissue's conductivity increasing more in the direction of the electrical field as this has been shown to occur in experiments. It was necessary to mathematically derive a valid form of the conductivity tensor such that it is dependent on the electrical field direction and can be easily implemented into numerical software. The derivation of a conductivity tensor that can take arbitrary functions for the conductivity in the directions tangent and normal to the electrical field is the main contribution of this paper. Numerical simulations were performed for isotropic-varying and anisotropic-varying conductivities to evaluate the importance of including the electrical field's direction in the formulation for conductivity. By starting from previously published experimental results, this paper derived a general formulation for an anistropic-varying tensor for implementation into irreversible electroporation modeling software. The anistropic-varying tensor formulation allows the conductivity to take into consideration both electrical field direction and magnitude, as opposed to previous published works that only took into account electrical field magnitude. The anisotropic formulation predicts roughly a five percent decrease in ablation size for the monopolar simulation and approximately a ten percent decrease in ablation size for the bipolar simulations. This is a positive result as previously reported results found the isotropic formulation to overpredict ablation size for both monopolar and bipolar simulations. Furthermore, it was also reported that the isotropic formulation overpredicts the ablation size more for the bipolar case than the monopolar case. Thus, our

Analysis of time-varying psoriasis lesion image patterns

DEFF Research Database (Denmark)

Maletti, Gabriela Mariel; Ersbøll, Bjarne Kjær; Nielsen, Allan Aasbjerg

2004-01-01

The multivariate alteration detection transform is applied to pairs of within and between time varying registered psoriasis image patterns. Color band contribution to the variates explaining maximal change is analyzed.......The multivariate alteration detection transform is applied to pairs of within and between time varying registered psoriasis image patterns. Color band contribution to the variates explaining maximal change is analyzed....

Specimen loading list for the varying temperature experiment

International Nuclear Information System (INIS)

Qualls, A.L.; Sitterson, R.G.

1998-01-01

The varying temperature experiment HFIR-RB-13J has been assembled and inserted in the reactor. Approximately 5300 specimens were cleaned, inspected, matched, and loaded into four specimen holders. A listing of each specimen loaded into the steady temperature holder, its position in the capsule, and the identification of the corresponding specimen loaded into the varying temperature holder is presented in this report

Wide-Range Adaptive RF-to-DC Power Converter for UHF RFIDs

KAUST Repository

Ouda, Mahmoud H.

2016-07-27

A wide-range, differential, cross-coupled rectifier is proposed with an extended dynamic range of input RF power that enables wireless powering from varying distances. The proposed architecture mitigates the reverse-leakage problem in conven- tional, cross-coupled rectifiers without degrading sensitivity. A prototype is designed for UHF RFID applications, and is imple- mented using 0.18 μ m CMOS technology. On-chip measurements demonstrate a sensitivity of − 18 dBm for 1 V output over a 100 k Ω load and a peak RF-to-DC power conversion efficiency of 65%. A conventional, fully cross-coupled rectifier is fabricated along- side for comparison and the proposed rectifier shows more than 2 × increase in dynamic range and a 25% boosting in output voltage than the conventional rectifier

Genome wide linkage disequilibrium in Chinese asparagus bean (Vigna. unguiculata ssp. sesquipedialis) germplasm: implications for domestication history and genome wide association studies.

Science.gov (United States)

Xu, P; Wu, X; Wang, B; Luo, J; Liu, Y; Ehlers, J D; Close, T J; Roberts, P A; Lu, Z; Wang, S; Li, G

2012-07-01

Association mapping of important traits of crop plants relies on first understanding the extent and patterns of linkage disequilibrium (LD) in the particular germplasm being investigated. We characterize here the genetic diversity, population structure and genome wide LD patterns in a set of asparagus bean (Vigna. unguiculata ssp. sesquipedialis) germplasm from China. A diverse collection of 99 asparagus bean and normal cowpea accessions were genotyped with 1127 expressed sequence tag-derived single nucleotide polymorphism markers (SNPs). The proportion of polymorphic SNPs across the collection was relatively low (39%), with an average number of SNPs per locus of 1.33. Bayesian population structure analysis indicated two subdivisions within the collection sampled that generally represented the 'standard vegetable' type (subgroup SV) and the 'non-standard vegetable' type (subgroup NSV), respectively. Level of LD (r(2)) was higher and extent of LD persisted longer in subgroup SV than in subgroup NSV, whereas LD decayed rapidly (0-2 cM) in both subgroups. LD decay distance varied among chromosomes, with the longest (≈ 5 cM) five times longer than the shortest (≈ 1 cM). Partitioning of LD variance into within- and between-subgroup components coupled with comparative LD decay analysis suggested that linkage group 5, 7 and 10 may have undergone the most intensive epistatic selection toward traits favorable for vegetable use. This work provides a first population genetic insight into domestication history of asparagus bean and demonstrates the feasibility of mapping complex traits by genome wide association study in asparagus bean using a currently available cowpea SNPs marker platform.

Varied line-space gratings and applications

International Nuclear Information System (INIS)

McKinney, W.R.

1991-01-01

This paper presents a straightforward analytical and numerical method for the design of a specific type of varied line-space grating system. The mathematical development will assume plane or nearly-plane spherical gratings which are illuminated by convergent light, which covers many interesting cases for synchrotron radiation. The gratings discussed will have straight grooves whose spacing varies across the principal plane of the grating. Focal relationships and formulae for the optical grating-pole-to-exist-slit distance and grating radius previously presented by other authors will be derived with a symbolic algebra system. It is intended to provide the optical designer with the tools necessary to design such a system properly. Finally, some possible advantages and disadvantages for application to synchrotron to synchrotron radiation beamlines will be discussed

A large-scale seroprevalence of Epstein-Barr virus in Taiwan.

Directory of Open Access Journals (Sweden)

Chao-Yu Chen

Full Text Available Epstein-Barr virus (EBV causes a variety of clinical manifestations from asymptomatic infection to acute infectious mononucleosis in human. Moreover, the EBV infection is associated with malignancies. The large-scale EBV seroepidemiology across all age groups has been lacking in Taiwan.A total of 1411 serum samples were tested to examine the seroprevalence of EBV in 2007. The samples were collected during an island-wide seroepidemiological survey of vaccine preventable diseases in Taiwan. The enzyme-linked immunosorbent assay was performed to detect anti-EBV viral capsid IgG in sera. Demographic and personal health data were obtained by questionnaires.The overall weighted seropositive rate of EBV was 88.5% (95% CI, 86.7%-90.1%. The seropositive rate of EBV reached 52.8% (95% CI, 44.0%-61.6% in children aged 2 years, rapidly rose to 88.7% (95% CI, 79.0%-95.1% in those aged 5-7 years and 93.0% (95%CI, 83.0%-98.1% for those aged 14-16 years. Age and higher educational level were associated with the increased EBV seropositive rate.In Taiwan, people had the EBV infection early in life. Children under 7 years should be the primary target popution of public health measures in the future.

A post-marketing safety and efficacy assessment of a monoclonal antibody purified high-purity factor VIII concentrate.

Science.gov (United States)

Hay, C R; Lee, C A; Savidge, G

1996-01-01

The identification of infrequent side-effects of clotting factor concentrates, undetected by clinical trials, is facilitated by post-marketing surveillance. We present a post-marketing surveillance study in which 97 patients with haemophilia A, attending three haemophilia centres, were treated over a median follow-up period of 284 days (range 1-1074), and a total follow-up period of 30,080 days, with a pasteurized immunoaffinity purified factor VIII concentrate (Monoclate-P, Armour, Collegeville, USA). 5216 infusions, using 10,527,000 units of Monoclate-P, were carried out, mostly for routine haemarthroses or prophylaxis. No new inhibitors were observed during the study. At the start of the study 60/97 were HIV seropositive, 67/97 HBs antibody positive, 12 HbsAb negative and the remainder HBsAb positive before the study period. 13/14 tested were HAV seropositive at the beginning of the study. One patient became HAV seropositive during the study period, an infection thought to be community acquired. No other seroconversions were observed. Only one mild transfusion reaction was observed. This study confirms the safety and efficacy of Monoclate-P. Post-marketing surveillance or nationally organized pharmaco-vigilance should be practiced more widely to enable identification of low-frequency side-effects of treatment.

Genome-wide characterization of the SiDof gene family in foxtail millet (Setaria italica).

Science.gov (United States)

Zhang, Li; Liu, Baoling; Zheng, Gewen; Zhang, Aiying; Li, Runzhi

2017-01-01

Dof (DNA binding with one finger) proteins, which constitute a class of transcription factors found exclusively in plants, are involved in numerous physiological and biochemical reactions affecting growth and development. A genome-wide analysis of SiDof genes was performed in this study. Thirty five SiDof genes were identified and those genes were unevenly distributed across nine chromosomes in the Seteria italica genome. Protein lengths, molecular weights, and theoretical isoelectric points of SiDofs all vary greatly. Gene structure analysis demonstrated that most SiDof genes lack introns. Phylogenetic analysis of SiDof proteins and Dof proteins from Arabidopsis thaliana, rice, sorghum, and Setaria viridis revealed six major groups. Analysis of RNA-Seq data indicated that SiDof gene expression levels varied across roots, stems, leaves, and spike. In addition, expression profiling of SiDof genes in response to stress suggested that SiDof 7 and SiDof 15 are involved in drought stress signalling. Overall, this study could provide novel information on SiDofs for further investigation in foxtail millet. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Eesti film võistleb Karlovy Varys

Index Scriptorium Estoniae

2008-01-01

8. juulil esilinastub Karlovy Vary filmifestivalil Rene Vilbre noortefilm "Mina olin siin", mille aluseks on Sass Henno romaan "Mina olin siin. Esimene arest", stsenaariumi kirjutas Ilmar Raag. Film võistleb võistlusprogrammis "East of the West"

Entropy Rate of Time-Varying Wireless Networks

DEFF Research Database (Denmark)

Cika, Arta; Badiu, Mihai Alin; Coon, Justin P.

2018-01-01

In this paper, we present a detailed framework to analyze the evolution of the random topology of a time-varying wireless network via the information theoretic notion of entropy rate. We consider a propagation channel varying over time with random node positions in a closed space and Rayleigh...... fading affecting the connections between nodes. The existence of an edge between two nodes at given locations is modeled by a Markov chain, enabling memory effects in network dynamics. We then derive a lower and an upper bound on the entropy rate of the spatiotemporal network. The entropy rate measures...

Seroprevalence of hepatitis C and associated risk factors among an urban population in Haiti

OpenAIRE

Hepburn, Matthew J; Lawitz, Eric J

2004-01-01

Abstract Background The seroprevalence of hepatitis C varies substantially between countries and geographic regions. A better understanding of the seroprevalence of this disease, and the risk factors associated with seropositive status, supply data for the development of screening programs and provide insight into the transmission of the disease. The purpose of this investigation was to determine the seroprevalence of hepatitis C and associated risk factors in an urban population in Haiti. Me...

Possible interaction between myxomatosis and calicivirosis related to rabbit haemorrhagic disease affecting the European rabbit.

Science.gov (United States)

Marchandeau, S; Bertagnoli, S; Peralta, B; Boucraut-Baralon, C; Letty, J; Reitz, F

2004-11-06

Serological data on myxoma virus, rabbit haemorrhagic disease (RHD) virus and RHD-like viruses in juvenile rabbits (Oryctolagus cuniculus) trapped in 1995, 1996 and 1997 in two areas of France were analysed. For each disease, the effects of bodyweight, year, month and seropositivity for the other disease were modelled by using logistic regressions. In one area, a model including RHD seropositivity was selected to explain the myxoma virus seropositivity. Models including myxoma virus seropositivity were selected to explain the RHD seropositivity in both areas, and the odds of a rabbit being seropositive to both viruses were 5.1 and 8.4 times higher than the odds of a rabbit being seronegative to myxoma virus and seropositive to RHD. The year and bodyweight had significant effects for myxomatosis in one area and for RHD in both areas.

Penalized Nonlinear Least Squares Estimation of Time-Varying Parameters in Ordinary Differential Equations

KAUST Repository

Cao, Jiguo; Huang, Jianhua Z.; Wu, Hulin

2012-01-01

Ordinary differential equations (ODEs) are widely used in biomedical research and other scientific areas to model complex dynamic systems. It is an important statistical problem to estimate parameters in ODEs from noisy observations. In this article we propose a method for estimating the time-varying coefficients in an ODE. Our method is a variation of the nonlinear least squares where penalized splines are used to model the functional parameters and the ODE solutions are approximated also using splines. We resort to the implicit function theorem to deal with the nonlinear least squares objective function that is only defined implicitly. The proposed penalized nonlinear least squares method is applied to estimate a HIV dynamic model from a real dataset. Monte Carlo simulations show that the new method can provide much more accurate estimates of functional parameters than the existing two-step local polynomial method which relies on estimation of the derivatives of the state function. Supplemental materials for the article are available online.

LTR real-time PCR for HIV-1 DNA quantitation in blood cells for early diagnosis in infants born to seropositive mothers treated in HAART area (ANRS CO 01).

Science.gov (United States)

Avettand-Fènoël, Véronique; Chaix, Marie-Laure; Blanche, Stéphane; Burgard, Marianne; Floch, Corinne; Toure, Kadidia; Allemon, Marie-Christine; Warszawski, Josiane; Rouzioux, Christine

2009-02-01

HIV-1 diagnosis in babies born to seropositive mothers is one of the challenges of HIV epidemics in children. A simple, rapid protocol was developed for quantifying HIV-1 DNA in whole blood samples and was used in the ANRS French pediatric cohort in conditions of prevention of mother-to-child transmission. A quantitative HIV-1 DNA protocol (LTR real-time PCR) requiring small blood volumes was developed. First, analytical reproducibility was evaluated on 172 samples. Results obtained on blood cell pellets and Ficoll-Hypaque separated mononuclear cells were compared in 48 adult HIV-1 samples. Second, the protocol was applied to HIV-1 diagnosis in infants in parallel with plasma HIV-RNA quantitation. This prospective study was performed in children born between May 2005 and April 2007 included in the ANRS cohort. The assay showed good reproducibility. The 95% detection cut-off value was 6 copies/PCR, that is, 40 copies/10(6) leukocytes. HIV-DNA levels in whole blood were highly correlated with those obtained after Ficoll-Hypaque separation (r = 0.900, P mothers have received HAART. (c) 2008 Wiley-Liss, Inc.

Multivariate time-varying volatility modeling using probabilistic fuzzy systems

NARCIS (Netherlands)

Basturk, N.; Almeida, R.J.; Golan, R.; Kaymak, U.

2016-01-01

Methods to accurately analyze financial risk have drawn considerable attention in financial institutions. One difficulty in financial risk analysis is the fact that banks and other financial institutions invest in several assets which show time-varying volatilities and hence time-varying financial

Unit 148 - World Wide Web Basics

OpenAIRE

148, CC in GIScience; Yeung, Albert K.

2000-01-01

This unit explains the characteristics and the working principles of the World Wide Web as the most important protocol of the Internet. Topics covered in this unit include characteristics of the World Wide Web; using the World Wide Web for the dissemination of information on the Internet; and using the World Wide Web for the retrieval of information from the Internet.

World Wide Web voted most wonderful wonder by web-wide world

CERN Multimedia

2007-01-01

The results are in, and the winner is...the World Wide Web! An online survey conducted by the CNN news group ranks the World Wide Web-invented at CERN--as the most wonderful of the seven modern wonders of the world. (See Bulletin No. 49/2006.) There is currently no speculation about whether they would have had the same results had they distributed the survey by post. The World Wide Web won with a whopping 50 per cent of the votes (3,665 votes). The runner up was CERN again, with 16 per cent of voters (1130 votes) casting the ballot in favour of the CERN particle accelerator. Stepping into place behind CERN and CERN is 'None of the Above' with 8 per cent of the votes (611 votes), followed by the development of Dubai (7%), the bionic arm (7%), China's Three Gorges Damn (5%), The Channel Tunnel (4%), and France's Millau viaduct (3%). Thanks to everyone from CERN who voted. You can view the results on http://edition.cnn.com/SPECIALS/2006/modern.wonders/

Prevalence of Toxoplasma gondii antibodies in domestic donkeys (Equus asinus) in Durango, Mexico slaughtered for human consumption.

Science.gov (United States)

Alvarado-Esquivel, Cosme; Alvarado-Esquivel, Domingo; Dubey, Jitender P

2015-01-17

Nothing is known about Toxoplasma gondii prevalence in donkeys in Mexico. Meat from donkey is consumed by humans in Mexico and also exported to other countries. We sought to determine the presence of antibodies against T. gondii in 239 domestic donkeys (Equus asinus) for slaughter in Durango, Mexico using the modified agglutination test (MAT). Donkeys were sampled in four premises (trade centers) where donkeys were gather for shipment to abattoirs in other Mexican states. Antibodies to T. gondii were found in 26 (10.9%) of 239 donkeys, with MAT titers of 1:25 in 7, 1:50 in 11, 1:100 in 6, and 1:200 in 2. Seropositive donkeys were found in three (75%) of the four gathering premises studied. Seroprevalence in donkeys varied from 0% to 23.1% among gathering premises. The seroprevalence of T. gondii infection was comparable among donkeys regardless their age, sex or health status. Seropositivity to T. gondii was found in donkeys between 1 to 12 years old. Multivariate analysis showed that seropositivity to T. gondii was associated with the gathering premises (OR = 1.58; 95% CI: 1.11-2.24; P = 0.009). This is the first report of T. gondii infection in donkeys in Mexico. Results indicate that consumption of undercooked or raw meat from T. gondii-infected donkeys is potentially a source of T. gondii infection for humans.

Wide-angle imaging LIDAR (WAIL): a ground-based instrument for monitoring the thickness and density of optically thick clouds

International Nuclear Information System (INIS)

Love, Steven P.; Davis, A.B.; Rohde, C.A.; Ho, Cheng

2001-01-01

Traditional lidar provides little information on dense clouds beyond the range to their base (ceilometry), due to their extreme opacity. At most optical wavelengths, however, laser photons are not absorbed but merely scattered out of the beam, and thus eventually escape the cloud via multiple scattering, producing distinctive extended space- and time-dependent patterns which are, in essence, the cloud's radiative Green functions. These Green functions, essentially 'movies' of the time evolution of the spatial distribution of escaping light, are the primary data products of a new type of lidar: Wide Angle Imaging Lidar (WAIL). WAIL data can be used to infer both optical depth and physical thickness of clouds, and hence the cloud liquid water content. The instrumental challenge is to accommodate a radiance field varying over many orders of magnitude and changing over widely varying time-scales. Our implementation uses a high-speed microchannel plate/crossed delay line imaging detector system with a 60-degree full-angle field of view, and a 532 nm doubled Nd:YAG laser. Nighttime field experiments testing various solutions to this problem show excellent agreement with diffusion theory, and retrievals yield plausible values for the optical and geometrical parameters of the observed cloud decks.

A wide range and highly sensitive optical fiber pH sensor using polyacrylamide hydrogel

Science.gov (United States)

Pathak, Akhilesh Kumar; Singh, Vinod Kumar

2017-12-01

In the present study we report the fabrication and characterization of no-core fiber sensor (NCFS) using smart hydrogel coating for pH measurement. The no-core fiber (NCF) is stubbed between two single-mode fibers with SMA connector before immobilizing of smart hydrogel. The wavelength interrogation technique is used to calculate the sensitivity of the proposed sensor. The result shows a high sensitivity of 1.94 nm/pH for a wide range of pH values varied from 3 to 10 with a good linear response. In addition to high sensitivity, the fabricated sensor provides a fast response time with a good stability, repeatability and reproducibility.

Genetic polymorphisms in varied environments.

Science.gov (United States)

Powell, J R

1971-12-03

Thirteen experimenital populationis of Drosophila willistoni were maintained in cages, in some of which the environments were relatively constant and in others varied. After 45 weeks, the populations were assayed by gel electrophoresis for polymorphisms at 22 protein loci. The average heterozygosity per individual and the average unmber of alleles per locus were higher in populations maintained in heterogeneous environments than in populations in more constant enviroments.

Wide spectral band beam analysis

Science.gov (United States)

Aharon, Oren

2015-03-01

The reality in laser beam profiling is that measurements are performed over a wide spectrum of wavelengths and power ranges. Many applications use multiple laser wavelengths with very different power levels, a fact which dictates a need for a better measuring tool. Rapid progress in the fiber laser area has increased the demand for lasers in the wavelength range of 900 - 1030 nm, while the telecommunication market has increased the demand for wavelength range of 1300nm - 1600 nm, on the other hand the silicone chip manufacturing and mass production requirements tend to lower the laser wavelength towards the 190nm region. In many cases there is a need to combine several lasers together in order to perform a specific task. A typical application is to combine one visible laser for pointing, with a different laser for material processing with a very different wavelength and power level. The visible laser enables accurate pointing before the second laser is operated. The beam profile of the intensity distribution is an important parameter that indicates how a laser beam will behave in an application. Currently a lab, where many different lasers are used, will find itself using various laser beam profilers from several vendors with different specifications and accuracies. It is the propose of this article to present a technological breakthrough in the area of detectors, electronics and optics allowing intricate measurements of lasers with different wavelength and with power levels that vary many orders of magnitude by a single beam profiler.

Pemodelan Markov Switching Dengan Time-varying Transition Probability

OpenAIRE

Savitri, Anggita Puri; Warsito, Budi; Rahmawati, Rita

2016-01-01

Exchange rate or currency is an economic variable which reflects country's state of economy. It fluctuates over time because of its ability to switch the condition or regime caused by economic and political factors. The changes in the exchange rate are depreciation and appreciation. Therefore, it could be modeled using Markov Switching with Time-Varying Transition Probability which observe the conditional changes and use information variable. From this model, time-varying transition probabili...

Genome-wide scan of healthy human connectome discovers SPON1 gene variant influencing dementia severity

Science.gov (United States)

Jahanshad, Neda; Rajagopalan, Priya; Hua, Xue; Hibar, Derrek P.; Nir, Talia M.; Toga, Arthur W.; Jack, Clifford R.; Saykin, Andrew J.; Green, Robert C.; Weiner, Michael W.; Medland, Sarah E.; Montgomery, Grant W.; Hansell, Narelle K.; McMahon, Katie L.; de Zubicaray, Greig I.; Martin, Nicholas G.; Wright, Margaret J.; Thompson, Paul M.; Weiner, Michael; Aisen, Paul; Weiner, Michael; Aisen, Paul; Petersen, Ronald; Jack, Clifford R.; Jagust, William; Trojanowski, John Q.; Toga, Arthur W.; Beckett, Laurel; Green, Robert C.; Saykin, Andrew J.; Morris, John; Liu, Enchi; Green, Robert C.; Montine, Tom; Petersen, Ronald; Aisen, Paul; Gamst, Anthony; Thomas, Ronald G.; Donohue, Michael; Walter, Sarah; Gessert, Devon; Sather, Tamie; Beckett, Laurel; Harvey, Danielle; Gamst, Anthony; Donohue, Michael; Kornak, John; Jack, Clifford R.; Dale, Anders; Bernstein, Matthew; Felmlee, Joel; Fox, Nick; Thompson, Paul; Schuff, Norbert; Alexander, Gene; DeCarli, Charles; Jagust, William; Bandy, Dan; Koeppe, Robert A.; Foster, Norm; Reiman, Eric M.; Chen, Kewei; Mathis, Chet; Morris, John; Cairns, Nigel J.; Taylor-Reinwald, Lisa; Trojanowki, J.Q.; Shaw, Les; Lee, Virginia M.Y.; Korecka, Magdalena; Toga, Arthur W.; Crawford, Karen; Neu, Scott; Saykin, Andrew J.; Foroud, Tatiana M.; Potkin, Steven; Shen, Li; Khachaturian, Zaven; Frank, Richard; Snyder, Peter J.; Molchan, Susan; Kaye, Jeffrey; Quinn, Joseph; Lind, Betty; Dolen, Sara; Schneider, Lon S.; Pawluczyk, Sonia; Spann, Bryan M.; Brewer, James; Vanderswag, Helen; Heidebrink, Judith L.; Lord, Joanne L.; Petersen, Ronald; Johnson, Kris; Doody, Rachelle S.; Villanueva-Meyer, Javier; Chowdhury, Munir; Stern, Yaakov; Honig, Lawrence S.; Bell, Karen L.; Morris, John C.; Ances, Beau; Carroll, Maria; Leon, Sue; Mintun, Mark A.; Schneider, Stacy; Marson, Daniel; Griffith, Randall; Clark, David; Grossman, Hillel; Mitsis, Effie; Romirowsky, Aliza; deToledo-Morrell, Leyla; Shah, Raj C.; Duara, Ranjan; Varon, Daniel; Roberts, Peggy; Albert, Marilyn; Onyike, Chiadi; Kielb, Stephanie; Rusinek, Henry; de Leon, Mony J.; Glodzik, Lidia; De Santi, Susan; Doraiswamy, P. Murali; Petrella, Jeffrey R.; Coleman, R. Edward; Arnold, Steven E.; Karlawish, Jason H.; Wolk, David; Smith, Charles D.; Jicha, Greg; Hardy, Peter; Lopez, Oscar L.; Oakley, MaryAnn; Simpson, Donna M.; Porsteinsson, Anton P.; Goldstein, Bonnie S.; Martin, Kim; Makino, Kelly M.; Ismail, M. Saleem; Brand, Connie; Mulnard, Ruth A.; Thai, Gaby; Mc-Adams-Ortiz, Catherine; Womack, Kyle; Mathews, Dana; Quiceno, Mary; Diaz-Arrastia, Ramon; King, Richard; Weiner, Myron; Martin-Cook, Kristen; DeVous, Michael; Levey, Allan I.; Lah, James J.; Cellar, Janet S.; Burns, Jeffrey M.; Anderson, Heather S.; Swerdlow, Russell H.; Apostolova, Liana; Lu, Po H.; Bartzokis, George; Silverman, Daniel H.S.; Graff-Radford, Neill R.; Parfitt, Francine; Johnson, Heather; Farlow, Martin R.; Hake, Ann Marie; Matthews, Brandy R.; Herring, Scott; van Dyck, Christopher H.; Carson, Richard E.; MacAvoy, Martha G.; Chertkow, Howard; Bergman, Howard; Hosein, Chris; Black, Sandra; Stefanovic, Bojana; Caldwell, Curtis; Hsiung, Ging-Yuek Robin; Feldman, Howard; Mudge, Benita; Assaly, Michele; Kertesz, Andrew; Rogers, John; Trost, Dick; Bernick, Charles; Munic, Donna; Kerwin, Diana; Mesulam, Marek-Marsel; Lipowski, Kristina; Wu, Chuang-Kuo; Johnson, Nancy; Sadowsky, Carl; Martinez, Walter; Villena, Teresa; Turner, Raymond Scott; Johnson, Kathleen; Reynolds, Brigid; Sperling, Reisa A.; Johnson, Keith A.; Marshall, Gad; Frey, Meghan; Yesavage, Jerome; Taylor, Joy L.; Lane, Barton; Rosen, Allyson; Tinklenberg, Jared; Sabbagh, Marwan; Belden, Christine; Jacobson, Sandra; Kowall, Neil; Killiany, Ronald; Budson, Andrew E.; Norbash, Alexander; Johnson, Patricia Lynn; Obisesan, Thomas O.; Wolday, Saba; Bwayo, Salome K.; Lerner, Alan; Hudson, Leon; Ogrocki, Paula; Fletcher, Evan; Carmichael, Owen; Olichney, John; DeCarli, Charles; Kittur, Smita; Borrie, Michael; Lee, T.-Y.; Bartha, Rob; Johnson, Sterling; Asthana, Sanjay; Carlsson, Cynthia M.; Potkin, Steven G.; Preda, Adrian; Nguyen, Dana; Tariot, Pierre; Fleisher, Adam; Reeder, Stephanie; Bates, Vernice; Capote, Horacio; Rainka, Michelle; Scharre, Douglas W.; Kataki, Maria; Zimmerman, Earl A.; Celmins, Dzintra; Brown, Alice D.; Pearlson, Godfrey D.; Blank, Karen; Anderson, Karen; Saykin, Andrew J.; Santulli, Robert B.; Schwartz, Eben S.; Sink, Kaycee M.; Williamson, Jeff D.; Garg, Pradeep; Watkins, Franklin; Ott, Brian R.; Querfurth, Henry; Tremont, Geoffrey; Salloway, Stephen; Malloy, Paul; Correia, Stephen; Rosen, Howard J.; Miller, Bruce L.; Mintzer, Jacobo; Longmire, Crystal Flynn; Spicer, Kenneth; Finger, Elizabeth; Rachinsky, Irina; Rogers, John; Kertesz, Andrew; Drost, Dick

2013-01-01

Aberrant connectivity is implicated in many neurological and psychiatric disorders, including Alzheimer’s disease and schizophrenia. However, other than a few disease-associated candidate genes, we know little about the degree to which genetics play a role in the brain networks; we know even less about specific genes that influence brain connections. Twin and family-based studies can generate estimates of overall genetic influences on a trait, but genome-wide association scans (GWASs) can screen the genome for specific variants influencing the brain or risk for disease. To identify the heritability of various brain connections, we scanned healthy young adult twins with high-field, high-angular resolution diffusion MRI. We adapted GWASs to screen the brain’s connectivity pattern, allowing us to discover genetic variants that affect the human brain’s wiring. The association of connectivity with the SPON1 variant at rs2618516 on chromosome 11 (11p15.2) reached connectome-wide, genome-wide significance after stringent statistical corrections were enforced, and it was replicated in an independent subsample. rs2618516 was shown to affect brain structure in an elderly population with varying degrees of dementia. Older people who carried the connectivity variant had significantly milder clinical dementia scores and lower risk of Alzheimer’s disease. As a posthoc analysis, we conducted GWASs on several organizational and topological network measures derived from the matrices to discover variants in and around genes associated with autism (MACROD2), development (NEDD4), and mental retardation (UBE2A) significantly associated with connectivity. Connectome-wide, genome-wide screening offers substantial promise to discover genes affecting brain connectivity and risk for brain diseases. PMID:23471985

Observer-based linear parameter varying H∞ tracking control for hypersonic vehicles

Directory of Open Access Journals (Sweden)

Yiqing Huang

2016-11-01

Full Text Available This article aims to develop observer-based linear parameter varying output feedback H∞ tracking controller for hypersonic vehicles. Due to the complexity of an original nonlinear model of the hypersonic vehicle dynamics, a slow–fast loop linear parameter varying polytopic model is introduced for system stability analysis and controller design. Then, a state observer is developed by linear parameter varying technique in order to estimate the unmeasured attitude angular for slow loop system. Also, based on the designed linear parameter varying state observer, a kind of attitude tracking controller is presented to reduce tracking errors for all bounded reference attitude angular inputs. The closed-loop linear parameter varying system is proved to be quadratically stable by Lypapunov function technique. Finally, simulation results show that the developed linear parameter varying H∞ controller has good tracking capability for reference commands.

Comparison of different Kalman filter approaches in deriving time varying connectivity from EEG data.

Science.gov (United States)

Ghumare, Eshwar; Schrooten, Maarten; Vandenberghe, Rik; Dupont, Patrick

2015-08-01

Kalman filter approaches are widely applied to derive time varying effective connectivity from electroencephalographic (EEG) data. For multi-trial data, a classical Kalman filter (CKF) designed for the estimation of single trial data, can be implemented by trial-averaging the data or by averaging single trial estimates. A general linear Kalman filter (GLKF) provides an extension for multi-trial data. In this work, we studied the performance of the different Kalman filtering approaches for different values of signal-to-noise ratio (SNR), number of trials and number of EEG channels. We used a simulated model from which we calculated scalp recordings. From these recordings, we estimated cortical sources. Multivariate autoregressive model parameters and partial directed coherence was calculated for these estimated sources and compared with the ground-truth. The results showed an overall superior performance of GLKF except for low levels of SNR and number of trials.

Robust stability analysis of switched Hopfield neural networks with time-varying delay under uncertainty

International Nuclear Information System (INIS)

Huang He; Qu Yuzhong; Li Hanxiong

2005-01-01

With the development of intelligent control, switched systems have been widely studied. Here we try to introduce some ideas of the switched systems into the field of neural networks. In this Letter, a class of switched Hopfield neural networks with time-varying delay is investigated. The parametric uncertainty is considered and assumed to be norm bounded. Firstly, the mathematical model of the switched Hopfield neural networks is established in which a set of Hopfield neural networks are used as the individual subsystems and an arbitrary switching rule is assumed; Secondly, robust stability analysis for such switched Hopfield neural networks is addressed based on the Lyapunov-Krasovskii approach. Some criteria are given to guarantee the switched Hopfield neural networks to be globally exponentially stable for all admissible parametric uncertainties. These conditions are expressed in terms of some strict linear matrix inequalities (LMIs). Finally, a numerical example is provided to illustrate our results

Estrelas variáveis

OpenAIRE

Viana, Sérgio Manuel de Oliveira

2001-01-01

A observação do céu nocturno é uma prática que vem da Antiguidade. Desde então e durante muito tempo pensou-se que as estrelas mantinham o brilho constante. Assim foi até ao século XVI, quando David Fabricius observou uma estrela cujo brilho variava periodicamente. Dois séculos mais tarde, Jonh Goodricke descobriu uma segunda estrela e com o desenvolvimento de instrumentos de observação este conjunto foi muito alargado e hoje inclui o Sol.A variação do brilho das estrelas variáveis permite d...

Fires in Seasonally Dry Tropical Forest: Testing the Varying Constraints Hypothesis across a Regional Rainfall Gradient.

Science.gov (United States)

Mondal, Nandita; Sukumar, Raman

2016-01-01

The "varying constraints hypothesis" of fire in natural ecosystems postulates that the extent of fire in an ecosystem would differ according to the relative contribution of fuel load and fuel moisture available, factors that vary globally along a spatial gradient of climatic conditions. We examined if the globally widespread seasonally dry tropical forests (SDTFs) can be placed as a single entity in this framework by analyzing environmental influences on fire extent in a structurally diverse SDTF landscape in the Western Ghats of southern India, representative of similar forests in monsoonal south and southeast Asia. We used logistic regression to model fire extent with factors that represent fuel load and fuel moisture at two levels-the overall landscape and within four defined moisture regimes (between 700 and1700 mm yr-1)-using a dataset of area burnt and seasonal rainfall from 1990 to 2010. The landscape scale model showed that the extent of fire in a given year within this SDTF is dependent on the combined interaction of seasonal rainfall and extent burnt the previous year. Within individual moisture regimes the relative contribution of these factors to the annual extent burnt varied-early dry season rainfall (i.e., fuel moisture) was the predominant factor in the wettest regime, while wet season rainfall (i.e., fuel load) had a large influence on fire extent in the driest regime. Thus, the diverse structural vegetation types associated with SDTFs across a wide range of rainfall regimes would have to be examined at finer regional or local scales to understand the specific environmental drivers of fire. Our results could be extended to investigating fire-climate relationships in STDFs of monsoonal Asia.

Genome-Wide Association Study of Blood Pressure Traits by Hispanic/Latino Background: the Hispanic Community Health Study/Study of Latinos

OpenAIRE

Sofer, Tamar; Wong, Quenna; Hartwig, Fernando P.; Taylor, Kent; Warren, Helen R.; Evangelou, Evangelos; Cabrera, Claudia P.; Levy, Daniel; Kramer, Holly; Lange, Leslie A.; Horta, Bernardo L.; Liang, Jingjing; Le, Thu H.; Edwards, Digna R. Velez; Tayo, Bamidele O.

2017-01-01

Hypertension prevalence varies between ethnic groups, possibly due to differences in genetic, environmental, and cultural determinants. Hispanic/Latino Americans are a diverse and understudied population. We performed a genome-wide association study (GWAS) of blood pressure (BP) traits in 12,278 participants from the Hispanics Community Health Study/Study of Latinos (HCHS/SOL). In the discovery phase we identified eight previously unreported BP loci. In the replication stage, we tested these ...

[Current tuberculosis mortality world-wide].

Science.gov (United States)

Haefliger, E; Rieder, H L

1992-04-21

The mortality rate still is an important index for assessment of tuberculosis. Statistical records are kept on the mortality rate on a worldwide basis--more than in the case of other tuberculosis parameters. They allow us to make valuable comparisons. They are also useful because the mortality is closely related to the morbidity. The present thesis is based on comparative figures from the 1989 volume of the WHO Health Statistics Annual. Various countries have been specially selected by the publisher--and subsequently also by us--for sake of clarity. The figures vary strongly within these countries, which was to be expected. The mortality rate varies in Europe (for each 100,000 residents) e.g. from 0.2 in the Netherlands to 8.15 in the Soviet Union. In the Americas the rates vary from 0.4 for Canada to 12.9 for Ecuador. In the Western Pacific region the mortality rates vary from 0.35 for Australia to 14.65 for China. On a worldwide basis, the share of deaths from tuberculosis among all causes of death varies from 0.02% in the Netherlands to 2.10% in the Republic of Korea. The relation of tuberculosis deaths with regard to sexes in Switzerland: 75.7% men, 24.3% women, which is more or less the European average. The lower the mortality rate for tuberculosis are, the lower the difference between the sexes appears to be. Similar facts are found with regard to the distribution of tuberculosis deaths according to age groups: the lower the tuberculosis rate, the more tuberculosis is found in older age groups. The tuberculosis deaths are percentage-wise similarly distributed to the respiratory organs and the other tuberculosis forms.(ABSTRACT TRUNCATED AT 250 WORDS)

Time-Varying Value of Energy Efficiency in Michigan

Energy Technology Data Exchange (ETDEWEB)

Mims, Natalie; Eckman, Tom; Schwartz, Lisa C.

2018-04-02

Quantifying the time-varying value of energy efficiency is necessary to properly account for all of its benefits and costs and to identify and implement efficiency resources that contribute to a low-cost, reliable electric system. Historically, most quantification of the benefits of efficiency has focused largely on the economic value of annual energy reduction. Due to the lack of statistically representative metered end-use load shape data in Michigan (i.e., the hourly or seasonal timing of electricity savings), the ability to confidently characterize the time-varying value of energy efficiency savings in the state, especially for weather-sensitive measures such as central air conditioning, is limited. Still, electric utilities in Michigan can take advantage of opportunities to incorporate the time-varying value of efficiency into their planning. For example, end-use load research and hourly valuation of efficiency savings can be used for a variety of electricity planning functions, including load forecasting, demand-side management and evaluation, capacity planning, long-term resource planning, renewable energy integration, assessing potential grid modernization investments, establishing rates and pricing, and customer service (KEMA 2012). In addition, accurately calculating the time-varying value of efficiency may help energy efficiency program administrators prioritize existing offerings, set incentive or rebate levels that reflect the full value of efficiency, and design new programs.

Water Vapor, Temperature and Wind Profiles within Maize Canopy under in-Field Rainwater Harvesting with Wide and Narrow Runoff Strips

Directory of Open Access Journals (Sweden)

Weldemichael A. Tesfuhuney

2013-11-01

Full Text Available Micrometeorological measurements were used to evaluate heat and water vapor to describe the transpiration (Ev and soil evaporation (Es processes for wide and narrow runoff strips under in-field rainwater harvesting (IRWH system. The resulting sigmoid-shaped water vapor (ea in wide and narrow runoff strips varied in lower and upper parts of the maize canopy. In wide runoff strips, lapse conditions of ea extended from lowest measurement level (LP to the upper middle section (MU and inversion was apparent at the top of the canopy. The virtual potential temperature (θv profile showed no difference in middle section, but the lower and upper portion (UP had lower  in narrow, compared to wide, strips, and LP-UP changes of 0.6 K and 1.2 K were observed, respectively. The Ev and Es within the canopy increased the ea concentration as determined by the wind order of magnitude. The ea concentration reached peak at about 1.6 kPa at a range of wind speed value of 1.4–1.8 m∙s−1 and 2.0–2.4 m∙s−1 for wide and narrow treatments, respectively. The sparse maize canopy of the wide strips could supply more drying power of the air in response to atmospheric evaporative demand compared to narrow strips. This is due to the variation in air flow in wide and narrow runoff strips that change gradients in ea for evapotranspiration processes.

Modelling Time-Varying Volatility in Financial Returns

DEFF Research Database (Denmark)

Amado, Cristina; Laakkonen, Helinä

2014-01-01

The “unusually uncertain” phase in the global financial markets has inspired many researchers to study the effects of ambiguity (or “Knightian uncertainty”) on the decisions made by investors and their implications for the capital markets. We contribute to this literature by using a modified...... version of the time-varying GARCH model of Amado and Teräsvirta (2013) to analyze whether the increasing uncertainty has caused excess volatility in the US and European government bond markets. In our model, volatility is multiplicatively decomposed into two time-varying conditional components: the first...... being captured by a stable GARCH(1,1) process and the second driven by the level of uncertainty in the financial market....

"Mina olin siin" esilinastub Karlovy Varys

Index Scriptorium Estoniae

2008-01-01

Karlovy Vary filmifestivalil esilinastub Rene Vilbre noortefilm "Mina olin siin", mille aluseks on Sass Henno romaan "Mina olin siin. Esimene arest", stsenaariumi kirjutas Ilmar Raag. Film võistleb võistlusprogrammis "East of the West". Esitlema sõidavad R. Vilbre, R. Sildos, R. Kaljujärv, T. Tuisk

Ellipsometry with randomly varying polarization states

NARCIS (Netherlands)

Liu, F.; Lee, C. J.; Chen, J. Q.; E. Louis,; van der Slot, P. J. M.; Boller, K. J.; F. Bijkerk,

2012-01-01

We show that, under the right conditions, one can make highly accurate polarization-based measurements without knowing the absolute polarization state of the probing light field. It is shown that light, passed through a randomly varying birefringent material has a well-defined orbit on the Poincar

Varying Constants, Gravitation and Cosmology

Directory of Open Access Journals (Sweden)

Jean-Philippe Uzan

2011-03-01

Full Text Available Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.

Síndrome de Parsonage-Turner: relato de caso em paciente HIV soropositivo Parsonage-Turner Syndrome: case report of a HIV seropositive patient

Directory of Open Access Journals (Sweden)

Saulo Gomes de Oliveira

2010-01-01

Full Text Available A síndrome de Parsonage-Turner é uma doença rara que acomete a musculatura da cintura escapular levando à hipotrofia muscular e grande déficit motor. A etiologia é indeterminada; acredita-se que existam fatores infecciosos e autoimunes envolvidos. O diagnóstico é de exceção, e os principais diagnósticos diferenciais são hérnias discais cervicais, lesões do manguito rotador e doenças reumáticas. Na investigação diagnóstica realizamos exames laboratoriais, radiografias e ressonância magnética dos ombros e da coluna cervical com destaque para a eletroneuromiografia auxiliando no diagnóstico definitivo. Por se tratar de uma doença raramente associada à soropositividade do vírus HIV e pela importância do diagnóstico precoce para o melhor tratamento destes pacientes é que relatamos este caso.The Parsonage-Turner Syndrome is a rare disease that affects the muscles of the scapular girdle, leading to muscular atrophy and a large motor deficit. The etiology is unknown, but it is believed that infectious and autoimmune factors are involved. The diagnosis is made by exclusion, and the main differential diagnoses are cervical disc hernias, rotator cuff injuries and rheumatic diseases. During diagnostic research, we conducted laboratory tests, radiographs and MRI of the shoulder and cervical spine, with particular reference to electroneuromyography to help generate a definitive diagnosis. This case report is presented because it shows a disease that is rarely associated with HIV seropositivity and the importance of early diagnosis for better treatment of these patients.

Wide bandgap, strain-balanced quantum well tunnel junctions on InP substrates

International Nuclear Information System (INIS)

Lumb, M. P.; Yakes, M. K.; Schmieder, K. J.; Affouda, C. A.; Walters, R. J.; González, M.; Bennett, M. F.; Herrera, M.; Delgado, F. J.; Molina, S. I.

2016-01-01

In this work, the electrical performance of strain-balanced quantum well tunnel junctions with varying designs is presented. Strain-balanced quantum well tunnel junctions comprising compressively strained InAlAs wells and tensile-strained InAlAs barriers were grown on InP substrates using solid-source molecular beam epitaxy. The use of InAlAs enables InP-based tunnel junction devices to be produced using wide bandgap layers, enabling high electrical performance with low absorption. The impact of well and barrier thickness on the electrical performance was investigated, in addition to the impact of Si and Be doping concentration. Finally, the impact of an InGaAs quantum well at the junction interface is presented, enabling a peak tunnel current density of 47.6 A/cm 2 to be realized.

A wide temperature range irradiation cryostat for reasearch on solid state targets

Energy Technology Data Exchange (ETDEWEB)

Reeve, Scott; Dutz, Hartmut; Goertz, Stefan; Runkel, Stefan; Voge, Thomas [Physikalisches Institut, Universitaet Bonn (Germany)

2012-07-01

To qualitatively improve the data obtained in asymmetry measurements of scattering experiments the figure of merit (FOM) plays a major role and can reduce the data acquisition time when a certain precision in the measurement is needed. One of the defining factors for the improvement of the polarised experiment lies in the target choice and preparation, in particular the method employed to introduce the paramagnetic defects for the use of dynamic nuclear polarisation (DNP). To this end the Polarized Target Group in Bonn has developed a wide range temperature cryostat for the irradiation of potential target materials in which materials can be irradiated to varying doses at specified temperatures. The stable irradiation temperature of the materials can be controlled to within {+-}1 K over a range of 90 K

Wide bandgap, strain-balanced quantum well tunnel junctions on InP substrates

Energy Technology Data Exchange (ETDEWEB)

Lumb, M. P. [The George Washington University, Washington, DC 20037 (United States); US Naval Research Laboratory, Washington, DC 20375 (United States); Yakes, M. K.; Schmieder, K. J.; Affouda, C. A.; Walters, R. J. [US Naval Research Laboratory, Washington, DC 20375 (United States); González, M.; Bennett, M. F. [Sotera Defense Solutions, Annapolis Junction, Maryland 20701 (United States); US Naval Research Laboratory, Washington, DC 20375 (United States); Herrera, M.; Delgado, F. J.; Molina, S. I. [University of Cádiz, 11510, Puerto Real, Cádiz (Spain)

2016-05-21

In this work, the electrical performance of strain-balanced quantum well tunnel junctions with varying designs is presented. Strain-balanced quantum well tunnel junctions comprising compressively strained InAlAs wells and tensile-strained InAlAs barriers were grown on InP substrates using solid-source molecular beam epitaxy. The use of InAlAs enables InP-based tunnel junction devices to be produced using wide bandgap layers, enabling high electrical performance with low absorption. The impact of well and barrier thickness on the electrical performance was investigated, in addition to the impact of Si and Be doping concentration. Finally, the impact of an InGaAs quantum well at the junction interface is presented, enabling a peak tunnel current density of 47.6 A/cm{sup 2} to be realized.

Partially linear varying coefficient models stratified by a functional covariate

KAUST Repository

Maity, Arnab; Huang, Jianhua Z.

2012-01-01

We consider the problem of estimation in semiparametric varying coefficient models where the covariate modifying the varying coefficients is functional and is modeled nonparametrically. We develop a kernel-based estimator of the nonparametric

Synchronized Pulsed dc - dc Converter as Maximum Power Position Tracker with Wide Load and Insolation Variation for Stand Alone PV System

International Nuclear Information System (INIS)

Hardik, P. Desai; Ranjan Maheshwari

2011-01-01

This paper investigates the interest focused on employing parallel connected dc-dc converter with high tracking effectiveness under wide variation in environmental conditions (Insolation) and wide load variation. dc-dc converter is an essential part of the stand alone PV system. Paper also presents an approach on how duty cycle for maximum power position (MPP) is adjusted by taking care of varying load conditions and without iterative steps. Synchronized PWM pulses are employed for the converter. High tracking efficiency is achieved with continuous input and inductor current. In this approach, the converter can he utilized in buck as well in boost mode. The PV system simulation was verified and experimental results were in agreement to the presented scheme. (authors)

Desperate Prawns: Drivers of Behavioural Innovation Vary across Social Contexts in Rock Pool Crustaceans.

Science.gov (United States)

Duffield, Callum; Wilson, Alastair J; Thornton, Alex

2015-01-01

Innovative behaviour may allow animals to cope with changes in their environment. Innovative propensities are known to vary widely both between and within species, and a growing body of research has begun to examine the factors that drive individuals to innovate. Evidence suggests that individuals are commonly driven to innovate by necessity; for instance by hunger or because they are physically unable to outcompete others for access to resources. However, it is not known whether the factors that drive individuals to innovate are stable across contexts. We examined contextual variation in the drivers of innovation in rock pool prawns (Palaemon spp), invertebrates that face widely fluctuating environments and may, through the actions of tides and waves, find themselves isolated or in groups. Using two novel foraging tasks, we examined the effects of body size and hunger in prawns tested in solitary and group contexts. When tested alone, small prawns were significantly more likely to succeed in a spatial task, and faster to reach the food in a manipulation task, while hunger state had no effect. In contrast, size had no effect when prawns were tested in groups, but food-deprived individuals were disproportionately likely to innovate in both tasks. We suggest that contextual variation in the drivers of innovation is likely to be common in animals living in variable environments, and may best be understood by considering variation in the perception of relative risks and rewards under different conditions.

Identification of time-varying nonlinear systems using differential evolution algorithm

DEFF Research Database (Denmark)

Perisic, Nevena; Green, Peter L; Worden, Keith

2013-01-01

(DE) algorithm for the identification of time-varying systems. DE is an evolutionary optimisation method developed to perform direct search in a continuous space without requiring any derivative estimation. DE is modified so that the objective function changes with time to account for the continuing......, thus identification of time-varying systems with nonlinearities can be a very challenging task. In order to avoid conventional least squares and gradient identification methods which require uni-modal and double differentiable objective functions, this work proposes a modified differential evolution...... inclusion of new data within an error metric. This paper presents results of identification of a time-varying SDOF system with Coulomb friction using simulated noise-free and noisy data for the case of time-varying friction coefficient, stiffness and damping. The obtained results are promising and the focus...

Compilation of Instantaneous Source Functions for Varying ...

African Journals Online (AJOL)

Compilation of Instantaneous Source Functions for Varying Architecture of a Layered Reservoir with Mixed Boundaries and Horizontal Well Completion Part IV: Normal and Inverted Letter 'h' and 'H' Architecture.

World-wide environmental problems

International Nuclear Information System (INIS)

Wohlers, H.C.

1975-01-01

Man and the physical and natural resources necessary to support him in a civilized society are on a collision course. It is simple to say that man cannot continue to grow in number at an ever-increasing rate without a destructive effect upon the environment. Positive scientific proof for this impending calamity is not now available, yet many indications--sometimes physical and sometimes natural--point toward major world-wide environmental troubles in the near future. A number of environmental problems are described, particularly as they relate to the total world system. A computer model simulating future world-wide environmental trends from 1900 to 2100 A.D. is evaluated and suggested as a major tool for data-gathering purposes to determine the extent of world-wide environmental problems. It is suggested that scientists take an active role in the study of the environment, particularly in relation to man's future on earth

Studying the mechanisms of language learning by varying the learning environment and the learner.

Science.gov (United States)

Goldin-Meadow, Susan

Language learning is a resilient process, and many linguistic properties can be developed under a wide range of learning environments and learners. The first goal of this review is to describe properties of language that can be developed without exposure to a language model - the resilient properties of language - and to explore conditions under which more fragile properties emerge. But even if a linguistic property is resilient, the developmental course that the property follows is likely to vary as a function of learning environment and learner, that is, there are likely to be individual differences in the learning trajectories children follow. The second goal is to consider how the resilient properties are brought to bear on language learning when a child is exposed to a language model. The review ends by considering the implications of both sets of findings for mechanisms, focusing on the role that the body and linguistic input play in language learning.

Damping of Inter-Area Low Frequency Oscillation Using an Adaptive Wide-Area Damping Controller

DEFF Research Database (Denmark)

Yao, Wei; Jiang, L.; Fang, Jiakun

2013-01-01

This paper presents an adaptive wide-area damping controller (WADC) based on generalized predictive control (GPC) and model identification for damping the inter-area low frequency oscillations in large-scale inter-connected power system. A recursive least-squares algorithm (RLSA) with a varying...... forgetting factor is applied to identify online the reduced-order linearlized model which contains dominant inter-area low frequency oscillations. Based on this linearlized model, the generalized predictive control scheme considering control output constraints is employed to obtain the optimal control signal...... conditions and different disturbances, but also has better robustness against to the time delay existing in the remote signals. The comparison studies with the conventional lead-lag WADC are also provided....

Varied appearance of lymphoma in patients with AIDS

International Nuclear Information System (INIS)

Sider, L.; Weiss, A.

1988-01-01

Lymphoma is frequently present in patients with acquired immunodeficiency (AIDS). But unlike in the general population, the appearance of lymphoma in patients with AIDS is extremely varied. The computed tomographic scans, chest radiographs, and subsequent hospital courses of 15 patients with AIDS-related lymphoma are presented. The patients presented with isolated pleural effusion (six patients), pleural and pericardial effusion (one patient), pulmonary infiltrates (five patients), and mediastinal adenopathy (three patients). This varied manner of presentation of lymphoma in AIDS patients should be recognized if diagnosis is to be made in the earlier stages of presentation

Compilation of Instantaneous Source Functions for Varying ...

African Journals Online (AJOL)

Compilation of Instantaneous Source Functions for Varying Architecture of a Layered Reservoir with Mixed Boundaries and Horizontal Well Completion Part III: B-Shaped Architecture with Vertical Well in the Upper Layer.

Varying hemin concentrations affect Porphyromonas gingivalis strains differently.

Science.gov (United States)

Ohya, Manabu; Cueno, Marni E; Tamura, Muneaki; Ochiai, Kuniyasu

2016-05-01

Porphyromonas gingivalis requires heme to grow, however, heme availability and concentration in the periodontal pockets vary. Fluctuations in heme concentration may affect each P. gingivalis strain differently, however, this was never fully demonstrated. Here, we elucidated the effects of varying hemin concentrations in representative P. gingivalis strains. Throughout this study, representative P. gingivalis strains [FDC381 (type I), MPWIb-01 (type Ib), TDC60 (type II), ATCC49417 (type III), W83 (type IV), and HNA99 (type V)] were used and grown for 24 h in growth media under varying hemin concentrations (5 × , 1 × , 0.5 × , 0.1 × ). Samples were lysed and protein standardized. Arg-gingipain (Rgp), H2O2, and superoxide dismutase (SOD) levels were subsequently measured. We focused our study on 24 h-grown strains which excluded MPWIb-01 and HNA99. Rgp activity among the 4 remaining strains varied with Rgp peaking at: 1 × for FDC381, 5 × for TDC60, 0.5 × for ATCC49417, 5 × and 0.5 × for W83. With regards to H2O2 and SOD amounts: FDC381 had similar H2O2 amounts in all hemin concentrations while SOD levels varied; TDC60 had the lowest H2O2 amount at 1 × while SOD levels became higher in relation to hemin concentration; ATCC49417 also had similar H2O2 amounts in all hemin concentrations while SOD levels were higher at 1 × and 0.5 × ; and W83 had statistically similar H2O2 and SOD amounts regardless of hemin concentration. Our results show that variations in hemin concentration affect each P. gingivalis strain differently. Published by Elsevier Ltd.

Pinning, de-pinning and re-pinning of a slowly varying rivulet

KAUST Repository

Paterson, C.; Wilson, S.K.; Duffy, B.R.

2013-01-01

The solutions for the unidirectional flow of a thin rivulet with prescribed volume flux down an inclined planar substrate are used to describe the locally unidirectional flow of a rivulet with constant width (i.e. pinned contact lines) but slowly varying contact angle as well as the possible pinning and subsequent de-pinning of a rivulet with constant contact angle and the possible de-pinning and subsequent re-pinning of a rivulet with constant width as they flow in the azimuthal direction from the top to the bottom of a large horizontal cylinder. Despite being the same locally, the global behaviour of a rivulet with constant width can be very different from that of a rivulet with constant contact angle. In particular, while a rivulet with constant non-zero contact angle can always run from the top to the bottom of the cylinder, the behaviour of a rivulet with constant width depends on the value of the width. Specifically, while a narrow rivulet can run all the way from the top to the bottom of the cylinder, a wide rivulet can run from the top of the cylinder only to a critical azimuthal angle. The scenario in which the hitherto pinned contact lines of the rivulet de-pin at the critical azimuthal angle and the rivulet runs from the critical azimuthal angle to the bottom of the cylinder with zero contact angle but slowly varying width is discussed. The pinning and de-pinning of a rivulet with constant contact angle, and the corresponding situation involving the de-pinning and re-pinning of a rivulet with constant width at a non-zero contact angle which generalises the de-pinning at zero contact angle discussed earlier, are described. In the latter situation, the mass of fluid on the cylinder is found to be a monotonically increasing function of the constant width. © 2013 Elsevier Masson SAS. All rights reserved.

Pinning, de-pinning and re-pinning of a slowly varying rivulet

KAUST Repository

Paterson, C.

2013-09-01

The solutions for the unidirectional flow of a thin rivulet with prescribed volume flux down an inclined planar substrate are used to describe the locally unidirectional flow of a rivulet with constant width (i.e. pinned contact lines) but slowly varying contact angle as well as the possible pinning and subsequent de-pinning of a rivulet with constant contact angle and the possible de-pinning and subsequent re-pinning of a rivulet with constant width as they flow in the azimuthal direction from the top to the bottom of a large horizontal cylinder. Despite being the same locally, the global behaviour of a rivulet with constant width can be very different from that of a rivulet with constant contact angle. In particular, while a rivulet with constant non-zero contact angle can always run from the top to the bottom of the cylinder, the behaviour of a rivulet with constant width depends on the value of the width. Specifically, while a narrow rivulet can run all the way from the top to the bottom of the cylinder, a wide rivulet can run from the top of the cylinder only to a critical azimuthal angle. The scenario in which the hitherto pinned contact lines of the rivulet de-pin at the critical azimuthal angle and the rivulet runs from the critical azimuthal angle to the bottom of the cylinder with zero contact angle but slowly varying width is discussed. The pinning and de-pinning of a rivulet with constant contact angle, and the corresponding situation involving the de-pinning and re-pinning of a rivulet with constant width at a non-zero contact angle which generalises the de-pinning at zero contact angle discussed earlier, are described. In the latter situation, the mass of fluid on the cylinder is found to be a monotonically increasing function of the constant width. © 2013 Elsevier Masson SAS. All rights reserved.

Consistency in the World Wide Web

DEFF Research Database (Denmark)

Thomsen, Jakob Grauenkjær

Tim Berners-Lee envisioned that computers will behave as agents of humans on the World Wide Web, where they will retrieve, extract, and interact with information from the World Wide Web. A step towards this vision is to make computers capable of extracting this information in a reliable...... and consistent way. In this dissertation we study steps towards this vision by showing techniques for the specication, the verication and the evaluation of the consistency of information in the World Wide Web. We show how to detect certain classes of errors in a specication of information, and we show how...... the World Wide Web, in order to help perform consistent evaluations of web extraction techniques. These contributions are steps towards having computers reliable and consistently extract information from the World Wide Web, which in turn are steps towards achieving Tim Berners-Lee's vision. ii...

R2R Eventlogger: Community-wide Recording of Oceanographic Cruise Science Events

Science.gov (United States)

Maffei, A. R.; Chandler, C. L.; Stolp, L.; Lerner, S.; Avery, J.; Thiel, T.

2012-12-01

Methods used by researchers to track science events during a science research cruise - and to note when and where these occur - varies widely. Handwritten notebooks, printed forms, watch-keeper logbooks, data-logging software, and customized software have all been employed. The quality of scientific results is affected by the consistency and care with which such events are recorded and integration of multi-cruise results is hampered because recording methods vary widely from cruise to cruise. The Rolling Deck to Repository (R2R) program has developed an Eventlogger system that will eventually be deployed on most vessels in the academic research fleet. It is based on the open software package called ELOG (http://midas.psi.ch/elog/) originally authored by Stefan Ritt and enhanced by our team. Lessons have been learned in its development and use on several research cruises. We have worked hard to find approaches that encourage cruise participants to use tools like the eventlogger. We examine these lessons and several eventlogger datasets from past cruises. We further describe how the R2R Science Eventlogger works in concert with the other R2R program elements to help coordinate research vessels into a coordinated mobile observing fleet. Making use of data collected on different research cruises is enabled by adopting common ways of describing science events, the science instruments employed, the data collected, etc. The use of controlled vocabularies and the practice of mapping these local vocabularies to accepted oceanographic community vocabularies helps to bind shipboard research events from different cruises into a more cohesive set of fleet-wide events that can be queried and examined in a cross-cruise manner. Examples of the use of the eventlogger during multi-cruise oceanographic research programs along with examples of resultant eventlogger data will be presented. Additionally we will highlight the importance of vocabulary use strategies to the success of the

Identification of Time-Varying Pilot Control Behavior in Multi-Axis Control Tasks

Science.gov (United States)

Zaal, Peter M. T.; Sweet, Barbara T.

2012-01-01

Recent developments in fly-by-wire control architectures for rotorcraft have introduced new interest in the identification of time-varying pilot control behavior in multi-axis control tasks. In this paper a maximum likelihood estimation method is used to estimate the parameters of a pilot model with time-dependent sigmoid functions to characterize time-varying human control behavior. An experiment was performed by 9 general aviation pilots who had to perform a simultaneous roll and pitch control task with time-varying aircraft dynamics. In 8 different conditions, the axis containing the time-varying dynamics and the growth factor of the dynamics were varied, allowing for an analysis of the performance of the estimation method when estimating time-dependent parameter functions. In addition, a detailed analysis of pilots adaptation to the time-varying aircraft dynamics in both the roll and pitch axes could be performed. Pilot control behavior in both axes was significantly affected by the time-varying aircraft dynamics in roll and pitch, and by the growth factor. The main effect was found in the axis that contained the time-varying dynamics. However, pilot control behavior also changed over time in the axis not containing the time-varying aircraft dynamics. This indicates that some cross coupling exists in the perception and control processes between the roll and pitch axes.

Spatially varying dispersion to model breakthrough curves.

Science.gov (United States)

Li, Guangquan

2011-01-01

Often the water flowing in a karst conduit is a combination of contaminated water entering at a sinkhole and cleaner water released from the limestone matrix. Transport processes in the conduit are controlled by advection, mixing (dilution and dispersion), and retention-release. In this article, a karst transport model considering advection, spatially varying dispersion, and dilution (from matrix seepage) is developed. Two approximate Green's functions are obtained using transformation of variables, respectively, for the initial-value problem and for the boundary-value problem. A numerical example illustrates that mixing associated with strong spatially varying conduit dispersion can cause strong skewness and long tailing in spring breakthrough curves. Comparison of the predicted breakthrough curve against that measured from a dye-tracing experiment between Ames Sink and Indian Spring, Northwest Florida, shows that the conduit dispersivity can be as large as 400 m. Such a large number is believed to imply strong solute interaction between the conduit and the matrix and/or multiple flow paths in a conduit network. It is concluded that Taylor dispersion is not dominant in transport in a karst conduit, and the complicated retention-release process between mobile- and immobile waters may be described by strong spatially varying conduit dispersion. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

Time-varying linear control for tiltrotor aircraft

Directory of Open Access Journals (Sweden)

Jing ZHANG

2018-04-01

Full Text Available Tiltrotor aircraft have three flight modes: helicopter mode, airplane mode, and transition mode. A tiltrotor has characteristics of highly nonlinear, time-varying flight dynamics and inertial/control couplings in its transition mode. It can transit from the helicopter mode to the airplane mode by tilting its nacelles, and an effective controller is crucial to accomplish tilting transition missions. Longitudinal dynamic characteristics of the tiltrotor are described by a nonlinear Lagrange-form model, which takes into account inertial/control couplings and aerodynamic interferences. Reference commands for airspeed velocity and attitude in the transition mode are calculated dynamically by visiting a command library which is founded in advance by analyzing the flight envelope of the tiltrotor. A Time-Varying Linear (TVL model is obtained using a Taylor-expansion based online linearization technique from the nonlinear model. Subsequently, based on an optimal control concept, an online optimization based control method with input constraints considered is proposed. To validate the proposed control method, three typical tilting transition missions are simulated using the nonlinear model of XV-15 tiltrotor aircraft. Simulation results show that the controller can be used to control the tiltrotor throughout its operating envelop which includes a transition flight, and can also deal with vertical gust disturbances. Keywords: Constrained optimal control, Inertia/control couplings, Tiltrotor aircraft, Time-varying control, Transition mode

Testing for time-varying loadings in dynamic factor models

DEFF Research Database (Denmark)

Mikkelsen, Jakob Guldbæk

Abstract: In this paper we develop a test for time-varying factor loadings in factor models. The test is simple to compute and is constructed from estimated factors and residuals using the principal components estimator. The hypothesis is tested by regressing the squared residuals on the squared...... there is evidence of time-varying loadings on the risk factors underlying portfolio returns for around 80% of the portfolios....

VariVis: a visualisation toolkit for variation databases

Directory of Open Access Journals (Sweden)

Smith Timothy D

2008-04-01

Full Text Available Abstract Background With the completion of the Human Genome Project and recent advancements in mutation detection technologies, the volume of data available on genetic variations has risen considerably. These data are stored in online variation databases and provide important clues to the cause of diseases and potential side effects or resistance to drugs. However, the data presentation techniques employed by most of these databases make them difficult to use and understand. Results Here we present a visualisation toolkit that can be employed by online variation databases to generate graphical models of gene sequence with corresponding variations and their consequences. The VariVis software package can run on any web server capable of executing Perl CGI scripts and can interface with numerous Database Management Systems and "flat-file" data files. VariVis produces two easily understandable graphical depictions of any gene sequence and matches these with variant data. While developed with the goal of improving the utility of human variation databases, the VariVis package can be used in any variation database to enhance utilisation of, and access to, critical information.

Frequency of CCR5 Delta-32 Mutation in Human Immunodeficiency Virus (HIV-seropositive and HIV-exposed Seronegative Individuals and in General Population of Medellin, Colombia

Directory of Open Access Journals (Sweden)

Francisco J Díaz

2000-04-01

Full Text Available Repeated exposure to human immunodeficiency virus (HIV does not always result in seroconversion. Modifications in coreceptors for HIV entrance to target cells are one of the factors that block the infection. We studied the frequency of Delta-32 mutation in ccr5 gene in Medellin, Colombia. Two hundred and eighteen individuals distributed in three different groups were analyzed for Delta-32 mutation in ccr5 gene by polymerase chain reaction (PCR: 29 HIV seropositive (SP, 39 exposed seronegative (ESN and 150 individuals as a general population sample (GPS. The frequency of the Delta-32 mutant allele was 3.8% for ESN, 2.7% for GPS and 1.7% for SP. Only one homozygous mutant genotype (Delta-32/Delta-32 was found among the ESN (2.6%. The heterozygous genotype (ccr5/Delta-32 was found in eight GPS (5.3%, in one SP (3.4% and in one ESN (2.6%. The differences in the allelic and genotypic frequencies among the three groups were not statistically significant. A comparison between the expected and the observed genotypic frequencies showed that these frequencies were significantly different for the ESN group, which indirectly suggests a protective effect of the mutant genotype (Delta-32/Delta-32. Since this mutant genotype explained the resistance of infection in only one of our ESN persons, different mechanisms of protection must be playing a more important role in this population.

New varying speed of light theories

International Nuclear Information System (INIS)

Magueijo, Joao

2003-01-01

We review recent work on the possibility of a varying speed of light (VSL). We start by discussing the physical meaning of a varying-c, dispelling the myth that the constancy of c is a matter of logical consistency. We then summarize the main VSL mechanisms proposed so far: hard breaking of Lorentz invariance; bimetric theories (where the speeds of gravity and light are not the same); locally Lorentz invariant VSL theories; theories exhibiting a colour-dependent speed of light; varying-c induced by extra dimensions (e.g. in the brane-world scenario); and field theories where VSL results from vacuum polarization or CPT violation. We show how VSL scenarios may solve the cosmological problems usually tackled by inflation, and also how they may produce a scale-invariant spectrum of Gaussian fluctuations, capable of explaining the WMAP data. We then review the connection between VSL and theories of quantum gravity, showing how 'doubly special' relativity has emerged as a VSL effective model of quantum space-time, with observational implications for ultra-high energy cosmic rays (UHECRs) and gamma ray bursts. Some recent work on the physics of 'black' holes and other compact objects in VSL theories is also described, highlighting phenomena associated with spatial (as opposed to temporal) variations in c. Finally, we describe the observational status of the theory. The evidence is currently slim-redshift dependence in the atomic fine structure, anomalies with UHECRs, and (to a much lesser extent) the acceleration of the universe and the WMAP data. The constraints (e.g. those arising from nucleosynthesis or geological bounds) are tight but not insurmountable. We conclude with the observational predictions of the theory and the prospects for its refutation or vindication

Comparative brain pathology of HIV-seronegative and HIV-infected drug addicts.

Science.gov (United States)

Makrigeorgi-Butera, M; Hagel, C; Laas, R; Puschel, K; Stavrou, D

1996-01-01

Early stages of infection with human immunodeficiency virus (HIV) were studied in HIV-seropositive drug addicts. Since heroin users are immunocompromized even in the absence of HIV infection, the aim of the present study was to compare the morphological alterations present in HIV-seronegative and HIV-seropositive drug addicts. A total of 60 cases (32 HIV-seronegative subjects, 21 HIV-seropositive patients without signs of acquired immunodeficiency syndrome (AIDS), and 7 HIV-seropositive patients with signs of AIDS) were investigated macroscopically, histologically, and immunohistochemically HIV-seronegative patients presented more frequently with acute drug intoxication, died at a significantly younger age than HIV-seropositive patients, and were found to suffer more frequently from alcohol-related changes. These results indicated that HIV-seronegative and HIV-seropositive patients differed possibly in their drug consumption and also in their general conditions of life. In accordance with previous reports activated microglia and a diffuse astrogliosis in the white matter were detected at a significantly higher frequency and found to be more severe in HIV-seropositive subjects than in HIV-seronegative addicts. A lymphocytic meningitis was present in 6 of 21 HIV-seropositive patients but in none of the HIV-seronegative patients. Perivascular infiltrates consisting of lymphocytes and macrophages were detected at similar frequencies in HIV-seronegative and HIV-seropositive patients but were significantly more severe in patients suffering from lymphocytic meningitis or purulent encephalitis. Opportunistic infections were only demonstrated in 2 AIDS cases. In 10 of the HIV-seronegative patients and in 3 of the HIV-seropositive patients CD68-and Ham56-positive multinucleated cells were detected scattered in the subarachnoidal space exclusively over the frontal cortex.

Michelson wide-field stellar interferometry

NARCIS (Netherlands)

Montilla, I.

2004-01-01

The main goal of this thesis is to develop a system to permit wide field operation of Michelson Interferometers. A wide field of view is very important in applications such as the observation of extended or multiple objects, the fringe acquisition and/ or tracking on a nearby unresolved object, and

Varying prior information in Bayesian inversion

International Nuclear Information System (INIS)

Walker, Matthew; Curtis, Andrew

2014-01-01

Bayes' rule is used to combine likelihood and prior probability distributions. The former represents knowledge derived from new data, the latter represents pre-existing knowledge; the Bayesian combination is the so-called posterior distribution, representing the resultant new state of knowledge. While varying the likelihood due to differing data observations is common, there are also situations where the prior distribution must be changed or replaced repeatedly. For example, in mixture density neural network (MDN) inversion, using current methods the neural network employed for inversion needs to be retrained every time prior information changes. We develop a method of prior replacement to vary the prior without re-training the network. Thus the efficiency of MDN inversions can be increased, typically by orders of magnitude when applied to geophysical problems. We demonstrate this for the inversion of seismic attributes in a synthetic subsurface geological reservoir model. We also present results which suggest that prior replacement can be used to control the statistical properties (such as variance) of the final estimate of the posterior in more general (e.g., Monte Carlo based) inverse problem solutions. (paper)

Evaluation of Immunity and Seropositivity of IgG Antibodies to Canine Parvoviruses in Vaccinated and Unvaccinated Dogs in Abeokuta, Nigeria.

Science.gov (United States)

Babalola, E T; Ijaopo, O K; Okonko, I O

2016-01-01

Canine Parvovirus (CPV) is a very contagious and virulent viral disease affecting domestic dogs all over the world causing high morbidity and mortality in dogs, especially puppies. This study aimed at determining the seropositivity of IgG antibodies against CPV in vaccinated and unvaccinated dogs and to evaluate the immune status of dogs presented in Abeokuta. Forty-eight dogs were enrolled in this study. These dogs were presented at random for treatment, routine checkup, and vaccination at the State Veterinary Hospital and Veterinary Teaching Hospital all in Abeokuta. All the dogs were fully maintained under domestic setting. Selection for study was done based on thorough examination of the dogs and their medical records. The clients were informed of the nature of the investigation. Blood samples were collected and analyzed for anti-CPV-IgG. In principle, protective immunity correlates with high antibody titers and this was determined using a commercially available immunocomb® test kit for anti-CPV IgG antibody. Of 48 dogs sampled, 38 (79.2%) had high level of anti-CPV antibody titer and 10 (20.8%) had low level of anti-CPV antibody titer. Twenty six (54.2%) were males while 22 (45.8%) were females. Forty-five (93.75%) dogs were exotic breeds while 3 (6.25%) dogs were mongrels. Thirty (62.5%) of the dogs were less than one year old and the age range of all dogs sampled was between 7 weeks and 7 years. There was no significant difference (P > 0.05) between sex and the level of immunity but significant differences (P canine parvovirus among dogs in Abeokuta, Nigeria. Of all variables evaluated, ages of dogs, breeds and post-vaccination period were the main correlates of the level of immunity to CPV. This study also showed agreement with previous studies in the diagnostic value of using the immunoblot ELISA assay for the rapid detection of anti-CPV IgG antibody.

The propagation of varied timescale perturbations in landscapes

Science.gov (United States)

Bingham, N.; Johnson, K. N.; Bookhagen, B.; Chadwick, O.

2016-12-01

The classic assumption of steady-state landscapes greatly simplifies models of earth-surface processes. Theoretically, steady-state denotes time independence, but in real landscapes steady-state requires a timescale over which to assume (or document) no change. In the past, poor spatiotemporal resolution of eroding landscapes necessitated that shorter timescale perturbations be ignored in favor of regional formulations of rock uplift = erosion, 105, 6 years. Now, novel techniques and technologies provide an opportunity to define local landscape response to various timescales of perturbations; thus, allowing us to consider multiple steady-states on adjacent watersheds or even along a single watershed. This study seeks to identify the physical propagation of varied timescale perturbations in landscapes in order to provide an updated geomorphic context for interpreting critical zone processes. At our study site - Santa Cruz Island (SCI), CA - perturbations include sea level and climate fluctuations over 105 years coupled with pulses of overgrazing and extreme storm events during the last 200 years. Comprehensive knickpoint location maps and dated marine and fill terraces tighten the spatiotemporal constraints on erosion for SCI. In addition, the island hosts a wide range of lithologies, allowing us to compare lithologic effects on landscape response to perturbations. Our study uses lidar point clouds and high resolution (0.25 and 1 m) digital elevation model analysis to segment landscapes by the degree of their response to perturbations. Landscape response is measured by increases in topographic roughness. We ascertain roughness by analyzing the changes in different terrain attributes on multiple spatial scales: catchment, sub-catchments and individual hillslopes. Terrain attributes utilized include slope, curvature, local relief, flowpath length and contributing catchment area. Statistical analysis of these properties indicates narrower ranges in values for regions

Time-varying properties of renal autoregulatory mechanisms

DEFF Research Database (Denmark)

Zou, Rui; Cupples, Will A; Yip, K P

2002-01-01

In order to assess the possible time-varying properties of renal autoregulation, time-frequency and time-scaling methods were applied to renal blood flow under broad-band forced arterial blood pressure fluctuations and single-nephron renal blood flow with spontaneous oscillations obtained from...... normotensive (Sprague-Dawley, Wistar, and Long-Evans) rats, and spontaneously hypertensive rats. Time-frequency analyses of normotensive and hypertensive blood flow data obtained from either the whole kidney or the single-nephron show that indeed both the myogenic and tubuloglomerular feedback (TGF) mechanisms...... have time-varying characteristics. Furthermore, we utilized the Renyi entropy to measure the complexity of blood-flow dynamics in the time-frequency plane in an effort to discern differences between normotensive and hypertensive recordings. We found a clear difference in Renyi entropy between...

Non-minimally coupled varying constants quantum cosmologies

International Nuclear Information System (INIS)

Balcerzak, Adam

2015-01-01

We consider gravity theory with varying speed of light and varying gravitational constant. Both constants are represented by non-minimally coupled scalar fields. We examine the cosmological evolution in the near curvature singularity regime. We find that at the curvature singularity the speed of light goes to infinity while the gravitational constant vanishes. This corresponds to the Newton's Mechanics limit represented by one of the vertex of the Bronshtein-Zelmanov-Okun cube [1,2]. The cosmological evolution includes both the pre-big-bang and post-big-bang phases separated by the curvature singularity. We also investigate the quantum counterpart of the considered theory and find the probability of transition of the universe from the collapsing pre-big-bang phase to the expanding post-big-bang phase

Wide-Field Imaging Using Nitrogen Vacancies

Science.gov (United States)

Englund, Dirk Robert (Inventor); Trusheim, Matthew Edwin (Inventor)

2017-01-01

Nitrogen vacancies in bulk diamonds and nanodiamonds can be used to sense temperature, pressure, electromagnetic fields, and pH. Unfortunately, conventional sensing techniques use gated detection and confocal imaging, limiting the measurement sensitivity and precluding wide-field imaging. Conversely, the present sensing techniques do not require gated detection or confocal imaging and can therefore be used to image temperature, pressure, electromagnetic fields, and pH over wide fields of view. In some cases, wide-field imaging supports spatial localization of the NVs to precisions at or below the diffraction limit. Moreover, the measurement range can extend over extremely wide dynamic range at very high sensitivity.

Development of a Piezoelectric Vacuum Sensing Component for a Wide Pressure Range

Directory of Open Access Journals (Sweden)

Bing-Yu Wang

2014-11-01

Full Text Available In this study, we develop a clamped–clamped beam-type piezoelectric vacuum pressure sensing element. The clamped–clamped piezoelectric beam is composed of a PZT layer and a copper substrate. A pair of electrodes is set near each end. An input voltage is applied to a pair of electrodes to vibrate the piezoelectric beam, and the output voltage is measured at the other pair. Because the viscous forces on the piezoelectric beam vary at different air pressures, the vibration of the beam depends on the vacuum pressure. The developed pressure sensor can sense a wide range of pressure, from 6.5 × 10−6 to 760 Torr. The experimental results showed that the output voltage is inversely proportional to the gas damping ratio, and thus, the vacuum pressure was estimated from the output voltage.

Do Time-Varying Covariances, Volatility Comovement and Spillover Matter?

OpenAIRE

Lakshmi Balasubramanyan

2005-01-01

Financial markets and their respective assets are so intertwined; analyzing any single market in isolation ignores important information. We investigate whether time varying volatility comovement and spillover impact the true variance-covariance matrix under a time-varying correlation set up. Statistically significant volatility spillover and comovement between US, UK and Japan is found. To demonstrate the importance of modelling volatility comovement and spillover, we look at a simple portfo...

Robust Stabilization of Nonlinear Systems with Uncertain Varying Control Coefficient

Directory of Open Access Journals (Sweden)

Zaiyue Yang

2014-01-01

Full Text Available This paper investigates the stabilization problem for a class of nonlinear systems, whose control coefficient is uncertain and varies continuously in value and sign. The study emphasizes the development of a robust control that consists of a modified Nussbaum function to tackle the uncertain varying control coefficient. By such a method, the finite-time escape phenomenon has been prevented when the control coefficient is crossing zero and varying its sign. The proposed control guarantees the asymptotic stabilization of the system and boundedness of all closed-loop signals. The control performance is illustrated by a numerical simulation.

Varying ultrasound power level to distinguish surgical instruments and tissue.

Science.gov (United States)

Ren, Hongliang; Anuraj, Banani; Dupont, Pierre E

2018-03-01

We investigate a new framework of surgical instrument detection based on power-varying ultrasound images with simple and efficient pixel-wise intensity processing. Without using complicated feature extraction methods, we identified the instrument with an estimated optimal power level and by comparing pixel values of varying transducer power level images. The proposed framework exploits the physics of ultrasound imaging system by varying the transducer power level to effectively distinguish metallic surgical instruments from tissue. This power-varying image-guidance is motivated from our observations that ultrasound imaging at different power levels exhibit different contrast enhancement capabilities between tissue and instruments in ultrasound-guided robotic beating-heart surgery. Using lower transducer power levels (ranging from 40 to 75% of the rated lowest ultrasound power levels of the two tested ultrasound scanners) can effectively suppress the strong imaging artifacts from metallic instruments and thus, can be utilized together with the images from normal transducer power levels to enhance the separability between instrument and tissue, improving intraoperative instrument tracking accuracy from the acquired noisy ultrasound volumetric images. We performed experiments in phantoms and ex vivo hearts in water tank environments. The proposed multi-level power-varying ultrasound imaging approach can identify robotic instruments of high acoustic impedance from low-signal-to-noise-ratio ultrasound images by power adjustments.

Prevalence of immunoglobulin G (IgG antibody to Neospora caninum in dairy cattle of Hamedan province, west of Iran

Directory of Open Access Journals (Sweden)

Jamal Gharekhani

2014-06-01

Full Text Available Bovine neosporosis caused by the apicomplexan protozoan parasite N. caninum, was initially recognized in 1989 and is now reported as a leading infectious cause of reproductive failure in dairy cattle in world wide. The aim of this study was to determine the seroprevalence of N. caninum infection in industrial dairy cattle of Hamedan province (west of Iran by ELISA method. Blood samples were collected from 492 cattle in 41 farms. Antibodies to N. caninum were found in 63(12.80% sera. A Significant difference was observed between seropositive cattle and dog presence in farm, dog contact with herd, abortion history and herd population. No significant differences were found between seropositive cattle and age as well as breed. This study is the first report of N. caninum infection in dairy cattle farms in Hamedan province. As per our knowledge, Neospora is an important factor in abortion of cattle in this region. Therefore, comprehensive studies for control strategies and improving management of dairy farms is necessary.

Effect of genital herpes on cervicovaginal HIV shedding in women co-infected with HIV AND HSV-2 in Tanzania.

Science.gov (United States)

Todd, Jim; Riedner, Gabriele; Maboko, Leonard; Hoelscher, Michael; Weiss, Helen A; Lyamuya, Eligius; Mabey, David; Rusizoka, Mary; Belec, Laurent; Hayes, Richard

2013-01-01

To compare the presence and quantity of cervicovaginal HIV among HIV seropositive women with clinical herpes, subclinical HSV-2 infection and without HSV-2 infection respectively; to evaluate the association between cervicovaginal HIV and HSV shedding; and identify factors associated with quantity of cervicovaginal HIV. Four groups of HIV seropositive adult female barworkers were identified and examined at three-monthly intervals between October 2000 and March 2003 in Mbeya, Tanzania: (1) 57 women at 70 clinic visits with clinical genital herpes; (2) 39 of the same women at 46 clinic visits when asymptomatic; (3) 55 HSV-2 seropositive women at 60 clinic visits who were never observed with herpetic lesions; (4) 18 HSV-2 seronegative women at 45 clinic visits. Associations of genital HIV shedding with HIV plasma viral load (PVL), herpetic lesions, HSV shedding and other factors were examined. Prevalence of detectable genital HIV RNA varied from 73% in HSV-2 seronegative women to 94% in women with herpetic lesions (geometric means 1634 vs 3339 copies/ml, p = 0.03). In paired specimens from HSV-2 positive women, genital HIV viral shedding was similar during symptomatic and asymptomatic visits. On multivariate regression, genital HIV RNA (log10 copies/mL) was closely associated with HIV PVL (β = 0.51 per log10 copies/ml increase, 95%CI:0.41-0.60, pgenital HIV than the presence of herpetic lesions. These data support a role of HSV-2 infection in enhancing HIV transmissibility.

Evaluation of the Leptospira species microscopic agglutination test in experimentally vaccinated cats and Leptospira species seropositivity in aged azotemic client-owned cats.

Science.gov (United States)

Shropshire, Sarah B; Veir, Julia K; Morris, Arianne K; Lappin, Michael R

2016-10-01

The objectives of this study were to validate the microscopic agglutination test (MAT) using feline sera, determine cross-reactivity of Borrelia burgdorferi antibodies in the MAT, and evaluate if there is an association between Leptospira species seropositivity in aged (⩾10 years) client-owned cats with and without azotemia (creatinine >2 g/dl). A four-serovar canine leptospiral vaccine was administered to two specific pathogen-free (SPF) cats on days 0 and 14. The MAT was performed intermittently until day 42 for the serovars Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, Pomona and Bratislava, with a cut-off value of ⩾1:100. Five purpose-bred cats were infested with wild-caught Ixodes scapularis adults with an average B burgdorferi infection rate of 50%, and tested for antibodies against B burgdorferi C6 peptide and DNA in skin biopsies, as well as by MAT. Sera from 66 azotemic and 75 non-azotemic cats ⩾10 years of age were tested for Leptospira species antibodies using the MAT and results were compared by the χ(2) test. Both SPF cats seroconverted by week 3 and formed antibodies against at least one serovar. There was no cross-reactivity in the MAT using samples from cats with antibodies to B burgdorferi. MAT results were positive for 4/66 azotemic cats and 8/75 non-azotemic cats; these results were not statistically different. The MAT can be interpreted using feline serum and does not appear to cross-react in cats with B burgdorferi antibodies. There was no association between Leptospira species MAT results and azotemia in this group of aged client-owned cats but further studies are needed to determine if leptospirosis contributes to feline chronic kidney disease. © The Author(s) 2015.

Genome-wide Selective Sweeps in Natural Bacterial Populations Revealed by Time-series Metagenomics

Energy Technology Data Exchange (ETDEWEB)

Chan, Leong-Keat; Bendall, Matthew L.; Malfatti, Stephanie; Schwientek, Patrick; Tremblay, Julien; Schackwitz, Wendy; Martin, Joel; Pati, Amrita; Bushnell, Brian; Foster, Brian; Kang, Dongwan; Tringe, Susannah G.; Bertilsson, Stefan; Moran, Mary Ann; Shade, Ashley; Newton, Ryan J.; Stevens, Sarah; McMcahon, Katherine D.; Mamlstrom, Rex R.

2014-05-12

Multiple evolutionary models have been proposed to explain the formation of genetically and ecologically distinct bacterial groups. Time-series metagenomics enables direct observation of evolutionary processes in natural populations, and if applied over a sufficiently long time frame, this approach could capture events such as gene-specific or genome-wide selective sweeps. Direct observations of either process could help resolve how distinct groups form in natural microbial assemblages. Here, from a three-year metagenomic study of a freshwater lake, we explore changes in single nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in populations of Chlorobiaceae and Methylophilaceae. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied considerably among closely related, co-occurring Methylophilaceae populations. SNP allele frequencies, as well as the relative abundance of certain genes, changed dramatically over time in each population. Interestingly, SNP diversity was purged at nearly every genome position in one of the Chlorobiaceae populations over the course of three years, while at the same time multiple genes either swept through or were swept from this population. These patterns were consistent with a genome-wide selective sweep, a process predicted by the ecotype model? of diversification, but not previously observed in natural populations.

Genome-wide Selective Sweeps in Natural Bacterial Populations Revealed by Time-series Metagenomics

Energy Technology Data Exchange (ETDEWEB)

Chan, Leong-Keat; Bendall, Matthew L.; Malfatti, Stephanie; Schwientek, Patrick; Tremblay, Julien; Schackwitz, Wendy; Martin, Joel; Pati, Amrita; Bushnell, Brian; Foster, Brian; Kang, Dongwan; Tringe, Susannah G.; Bertilsson, Stefan; Moran, Mary Ann; Shade, Ashley; Newton, Ryan J.; Stevens, Sarah; McMahon, Katherine D.; Malmstrom, Rex R.

2014-06-18

Multiple evolutionary models have been proposed to explain the formation of genetically and ecologically distinct bacterial groups. Time-series metagenomics enables direct observation of evolutionary processes in natural populations, and if applied over a sufficiently long time frame, this approach could capture events such as gene-specific or genome-wide selective sweeps. Direct observations of either process could help resolve how distinct groups form in natural microbial assemblages. Here, from a three-year metagenomic study of a freshwater lake, we explore changes in single nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in populations of Chlorobiaceae and Methylophilaceae. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied considerably among closely related, co-occurring Methylophilaceae populations. SNP allele frequencies, as well as the relative abundance of certain genes, changed dramatically over time in each population. Interestingly, SNP diversity was purged at nearly every genome position in one of the Chlorobiaceae populations over the course of three years, while at the same time multiple genes either swept through or were swept from this population. These patterns were consistent with a genome-wide selective sweep, a process predicted by the ‘ecotype model’ of diversification, but not previously observed in natural populations.

Response of rabbits to varying levels of cassava and Leucaena ...

African Journals Online (AJOL)

Response of rabbits to varying levels of cassava and Leucaena leucocephala leaf meal diets. ... Bulletin of Animal Health and Production in Africa ... An experiment was carried out to determine the performance, haematology, carcass characteristics and sensory evaluation of meat from rabbits (n = 30) fed varying levels of ...

The Thermal Collector With Varied Glass Covers

International Nuclear Information System (INIS)

Luminosu, I.; Pop, N.

2010-01-01

The thermal collector with varied glass covers represents an innovation realized in order to build a collector able to reach the desired temperature by collecting the solar radiation from the smallest surface, with the highest efficiency. In the case of the thermal collector with variable cover glasses, the number of the glass plates covering the absorber increases together with the length of the circulation pipe for the working fluid. The thermal collector with varied glass covers compared to the conventional collector better meet user requirements because: for the same temperature increase, has the collecting area smaller; for the same collection area, realizes the highest temperature increase and has the highest efficiency. This works is addressed to researchers in the solar energy and to engineers responsible with air-conditioning systems design or industrial and agricultural products drying.

Aquaporin-4 autoantibodies in neuromyelitis optica spectrum disorders: comparison between tissue-based and cell-based indirect immunofluorescence assays

Directory of Open Access Journals (Sweden)

Chan Koon H

2010-09-01

Full Text Available Abstract Background Neuromyelitis optica spectrum disorders (NMOSD are severe central nervous system inflammatory demyelinating disorders (CNS IDD characterized by monophasic or relapsing, longitudinally extensive transverse myelitis (LETM and/or optic neuritis (ON. A significant proportion of NMOSD patients are seropositive for aquaporin-4 (AQP4 autoantibodies. We compared the AQP4 autoantibody detection rates of tissue-based indirect immunofluorescence assay (IIFA and cell-based IIFA. Methods Serum of Chinese CNS IDD patients were assayed for AQP4 autoantibodies by tissue-based IIFA using monkey cerebellum and cell-based IIFA using transfected HEK293 cells which express human AQP4 on their cell membranes. Results In total, 128 CNS IDD patients were studied. We found that 78% of NMO patients were seropositive for AQP4 autoantibodies by cell-based IIFA versus 61% by tissue-based IFA (p = 0.250, 75% of patients having relapsing myelitis (RM with LETM were seropositive by cell-based IIFA versus 50% by tissue-based IIFA (p = 0.250, and 33% of relapsing ON patients were seropositive by cell-based IIFA versus 22% by tissue-based IIFA (p = 1.000; however the differences were not statistically significant. All patients seropositive by tissue-based IIFA were also seropositive for AQP4 autoantibodies by cell-based IIFA. Among 29 NMOSD patients seropositive for AQP4 autoantibodies by cell-based IIFA, 20 (69% were seropositive by tissue-based IIFA. The 9 patients seropositive by cell-based IIFA while seronegative by tissue-based IIFA had NMO (3, RM with LETM (3, a single attack of LETM (1, relapsing ON (1 and a single ON attack (1. Among 23 NMO or RM patients seropositive for AQP4 autoantibodies by cell-based IIFA, comparison between those seropositive (n = 17 and seronegative (n = 6 by tissue-based IIFA revealed no differences in clinical and neuroradiological characteristics between the two groups. Conclusion Cell-based IIFA is slightly more sensitive

Comprehensive evaluation of genome-wide 5-hydroxymethylcytosine profiling approaches in human DNA.

Science.gov (United States)

Skvortsova, Ksenia; Zotenko, Elena; Luu, Phuc-Loi; Gould, Cathryn M; Nair, Shalima S; Clark, Susan J; Stirzaker, Clare

2017-01-01

highlight both the advantages and caveats of three commonly used genome-wide 5hmC profiling technologies and show that interpretation of 5hmC data can be significantly influenced by the sensitivity of methods used, especially as the levels of 5hmC are low and vary in different cell types and different genomic locations.

A Unifying Perspective on Oxygen Vacancies in Wide Band Gap Oxides.

Science.gov (United States)

Linderälv, Christopher; Lindman, Anders; Erhart, Paul

2018-01-04

Wide band gap oxides are versatile materials with numerous applications in research and technology. Many properties of these materials are intimately related to defects, with the most important defect being the oxygen vacancy. Here, using electronic structure calculations, we show that the charge transition level (CTL) and eigenstates associated with oxygen vacancies, which to a large extent determine their electronic properties, are confined to a rather narrow energy range, even while band gap and the electronic structure of the conduction band vary substantially. Vacancies are classified according to their character (deep versus shallow), which shows that the alignment of electronic eigenenergies and CTL can be understood in terms of the transition between cavity-like localized levels in the large band gap limit and strong coupling between conduction band and vacancy states for small to medium band gaps. We consider both conventional and hybrid functionals and demonstrate that the former yields results in very good agreement with the latter provided that band edge alignment is taken into account.

Local tumor control and toxicity in HIV-associated anal carcinoma treated with radiotherapy in the era of antiretroviral therapy

International Nuclear Information System (INIS)

Oehler-Jänne, Christoph; Seifert, Burkhardt; Lütolf, Urs M; Ciernik, I Frank

2006-01-01

To investigate the outcome of HIV-seropositive patients under highly active antiretroviral treatment (HAART) with anal cancer treated with radiotherapy (RT) alone or in combination with standard chemotherapy (CT). Clinical outcome of 81 HIV-seronegative patients (1988 – 2003) and 10 consecutive HIV-seropositive patients under HAART (1997 – 2003) that were treated with 3-D conformal RT of 59.4 Gy and standard 5-fluorouracil and mitomycin-C were retrospectively analysed. 10 TNM-stage and age matched HIV-seronegative patients (1992 – 2003) were compared with the 10 HIV-seropositive patients. Pattern of care, local disease control (LC), overall survival (OS), cancer-specific survival (CSS), and toxicity were assessed. RT with or without CT resulted in complete response in 100 % of HIV-seropositive patients. LC was impaired compared to matched HIV-seronegative patients after a median follow-up of 44 months (p = 0.03). OS at 5 years was 70 % in HIV-seropositive patients receiving HAART and 69 % in the matched controls. Colostomy-free survival was 70 % (HIV+) and 100 % (matched HIV-) and 78 % (all HIV-). No HIV-seropositive patient received an interstitial brachytherapy boost compared to 42 % of all HIV-seronegative patients and adherence to chemotherapy seemed to be difficult in HIV-seropositive patients. Acute hematological toxicity reaching 50 % was high in HIV-seropositive patients receiving MMC compared with 0 % in matched HIV-seronegative patients (p = 0.05) or 12 % in all HIV-seronegative patients. The rate of long-term side effects was low in HIV-seropositive patients. Despite high response rates to organ preserving treatment with RT with or without CT, local tumor failure seems to be high in HIV-positive patients receiving HAART. HIV-seropositive patients are subject to treatment bias, being less likely treated with interstitial brachytherapy boost probably due to HIV-infection, and they are at risk to receive less chemotherapy

How Do Parenting Concepts Vary within and between the Families?

Science.gov (United States)

Roskam, Isabelle; Meunier, Jean Christophe

2009-01-01

How do parenting concepts vary within and between the families? The present study regards parenting as a complex family process by considering three concepts of parenting: styles, differential treatment and coparenting consistency. A main question was addressed: whether and how these parenting concepts vary within the families towards siblings or…

Modeling of Electricity Demand for Azerbaijan: Time-Varying Coefficient Cointegration Approach

Directory of Open Access Journals (Sweden)

Jeyhun I. Mikayilov

2017-11-01

Full Text Available Recent literature has shown that electricity demand elasticities may not be constant over time and this has investigated using time-varying estimation methods. As accurate modeling of electricity demand is very important in Azerbaijan, which is a transitional country facing significant change in its economic outlook, we analyze whether the response of electricity demand to income and price is varying over time in this economy. We employed the Time-Varying Coefficient cointegration approach, a cutting-edge time-varying estimation method. We find evidence that income elasticity demonstrates sizeable variation for the period of investigation ranging from 0.48% to 0.56%. The study has some useful policy implications related to the income and price aspects of the electricity consumption in Azerbaijan.

Munchausen Syndrome and the Wide Spectrum of Factitious Disorders.

Science.gov (United States)

Tatu, Laurent; Aybek, Selma; Bogousslavsky, Julien

2018-01-01

Since its initial description in 1851, Munchausen syndrome has been widely used interchangeably with factitious disorder. Nevertheless, this syndrome is only one form of factitious disorder that is both severe and chronic. The syndrome was named after Karl Friedrich Hieronymus, Baron von Münchhausen (1720-1797), a German nobleman who became famous as a narrator of false and exaggerated exploits. His name was progressively corrupted to Munchausen. Factitious disorders and Munchausen syndrome remain a great diagnosis challenge for physicians. All medical specialities are concerned by these disorders. The diagnosis process involves a first step to exclude an unusual presentation of a common medical condition. The second step consists of excluding somatoform disorders and malingering. Unfortunately, the boundaries between factitious disorder, somatization, and malingering are often unclear. In 1977, the term "Munchausen's syndrome by proxy" was coined to define a situation where a person produces false symptoms in another one, especially a child. This term was extended to similar interactions between human and pets. Because varied conditions have been included in the definition of this syndrome, there is ongoing debate about alternative names. © 2018 S. Karger AG, Basel.

Information on infantile colic on the World Wide Web.

Science.gov (United States)

Bailey, Shana D; D'Auria, Jennifer P; Haushalter, Jamie P

2013-01-01

The purpose of this study was to explore and describe the type and quality of information on infantile colic that a parent might access on the World Wide Web. Two checklists were used to evaluate the quality indicators of 24 Web sites and the colic-specific content. Fifteen health information Web sites met more of the quality parameters than the nine commercial sites. Eight Web sites included information about colic and infant abuse, with six being health information sites. The colic-specific content on 24 Web sites reflected current issues and controversies; however, the completeness of the information in light of current evidence varied among the Web sites. Strategies to avoid complications of parental stress or infant abuse were not commonly found on the Web sites. Pediatric professionals must guide parents to reliable colic resources that also include emotional support and understanding of infant crying. A best evidence guideline for the United States would eliminate confusion and uncertainty about which colic therapies are safe and effective for parents and professionals. Copyright © 2013 National Association of Pediatric Nurse Practitioners. Published by Mosby, Inc. All rights reserved.

Wide Bandgap Semiconductor Detector Optimization for Flash X-Ray Measurements

Energy Technology Data Exchange (ETDEWEB)

Roecker, Caleb Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Schirato, Richard C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-11-17

Charge trapping, resulting in a decreased and spatially dependent electric field, has long been a concern for wide bandgap semiconductor detectors. While significant work has been performed to characterize this degradation at varying temperatures and radiation environments, this work concentrates upon examining the event-to-event response in a flash X-ray environment. The following work investigates if charge trapping is a problem for CZT detectors, with particular emphasis on flash X-ray radiation fields at cold temperatures. Results are compared to a non-flash radiation field, using an Am-241 alpha source and similar temperature transitions. Our ability to determine if a response change occurred was hampered by the repeatability of our flash X-ray systems; a small response change was observed with the Am-241 source. Due to contrast of these results, we are in the process of revisiting the Am-241 measurements in the presence of a high radiation environment. If the response change is more pronounced in the high radiation environment, a similar test will be performed in the flash X-ray environment.

Identification of widely varying levels of resistance to meloidogyne incognita in sweet sorghum

Science.gov (United States)

Sweet sorghum (Sorghum bicolor) is a potential bioenergy crop that could be incorporated into annual cropping systems in the southern US, where it would likely be rotated with cotton. The desirability of including sweet sorghum in a cotton cropping system will be influenced by sweet sorghum’s host ...

Review of wide band-gap semiconductors technology

Directory of Open Access Journals (Sweden)

Jin Haiwei

2016-01-01

Full Text Available Silicon carbide (SiC and gallium nitride (GaN are typical representative of the wide band-gap semiconductor material, which is also known as third-generation semiconductor materials. Compared with the conventional semiconductor silicon (Si or gallium arsenide (GaAs, wide band-gap semiconductor has the wide band gap, high saturated drift velocity, high critical breakdown field and other advantages; it is a highly desirable semiconductor material applied under the case of high-power, high-temperature, high-frequency, anti-radiation environment. These advantages of wide band-gap devices make them a hot spot of semiconductor technology research in various countries. This article describes the research agenda of United States and European in this area, focusing on the recent developments of the wide band-gap technology in the US and Europe, summed up the facing challenge of the wide band-gap technology.

Introduction to the world wide web.

Science.gov (United States)

Downes, P K

2007-05-12

The World Wide Web used to be nicknamed the 'World Wide Wait'. Now, thanks to high speed broadband connections, browsing the web has become a much more enjoyable and productive activity. Computers need to know where web pages are stored on the Internet, in just the same way as we need to know where someone lives in order to post them a letter. This section explains how the World Wide Web works and how web pages can be viewed using a web browser.

Indoor measurement of photovoltaic device characteristics at varying irradiance, temperature and spectrum for energy rating

International Nuclear Information System (INIS)

Bliss, M; Betts, T R; Gottschalg, R

2010-01-01

The first three-dimensional performance matrix for use in photovoltaic (PV) energy rating is reported utilizing a novel energy rating solar simulator based on LEDs. Device characteristics are measured indoors at varying irradiance (G), temperature (T) and spectrum (E). This opens the possibility for a more accurate measurement system for energy yield prediction of PV devices, especially for devices with high spectral dependence such as wide bandgap solar cells as they take into account spectral changes in the light. The main aspects of the LED-based solar simulator used are briefly described. A measurement method is developed and detailed in the paper, which takes into account the current imperfections in the achievable spectrum. Measurement results for a crystalline silicon solar cell are used to demonstrate the measurement approach. An uncertainty analysis of the measurement system is given, resulting in an overall absolute uncertainty of 4.3% (coverage factor k = 2) in maximum power measurements at 765 W m −2 irradiance with scope for further improvements

Directional Wide-Angle Range Finder (DWARF)

Data.gov (United States)

National Aeronautics and Space Administration — The proposed innovation, the Directional Wide-Angle Range Finder (DWARF) is the creation of a laser range-finder with a wide field-of-view (FOV) and a directional...

Stabilization of the Wave Equation with Boundary Time-Varying Delay

Directory of Open Access Journals (Sweden)

Hao Li

2014-01-01

Full Text Available We study the stabilization of the wave equation with variable coefficients in a bounded domain and a time-varying delay term in the time-varying, weakly nonlinear boundary feedbacks. By the Riemannian geometry methods and a suitable assumption of nonlinearity, we obtain the uniform decay of the energy of the closed loop system.

Filmihullu eluvesi voolab Karlovy Varys / Margit Tõnson

Index Scriptorium Estoniae

Tõnson, Margit, 1978-

2010-01-01

Karlovy Vary rahvusvahelisest filmifestivalist. Filmidest "Mr. Nobody" (rež. Jaco Van Dormaeli), "Kasside ema Teresa" (rež. Pawel Sala) ja "The Arbor" (rež. Clio Barnardi). Nimekiri võitnud töödest ja viimastel aastatel festivalil näidatud Eesti mängufilmidest

Newtonian cosmology with a time-varying constant of gravitation

International Nuclear Information System (INIS)

McVittie, G.C.

1978-01-01

Newtonian cosmology is based on the Eulerian equations of fluid mechanics combined with Poisson's equation modified by the introduction of a time-varying G. Spherically symmetric model universes are worked out with instantaneously uniform densities. They are indeterminate unless instantaneous uniformity of the pressure is imposed. When G varies as an inverse power of the time, the models can in some cases be shown to depend on the solution of a second-order differential equation which also occurs in the Friedmann models of general relativity. In Section 3, a method for 'passing through' a singularity of this equation is proposed which entails making four arbitrary mathematical assumptions. When G varies as (time) -1 , models with initially cycloidal motion are possible, each cycle becoming longer as time progresses. Finally, gravitation becomes so weak that the model expands to infinity. Kinetic and potential energies for the whole model are derived from the basic equations; their sum is not constant. (author)

Seroprevalence of Brucellosis, Leptospirosis, and Q Fever among Butchers and Slaughterhouse Workers in South-Eastern Iran.

Science.gov (United States)

Esmaeili, Saber; Naddaf, Saied Reza; Pourhossein, Behzad; Hashemi Shahraki, Abdolrazagh; Bagheri Amiri, Fahimeh; Gouya, Mohammad Mehdi; Mostafavi, Ehsan

2016-01-01

Zoonotic diseases can be occupational hazards to people who work in close contact with animals or their carcasses. In this cross-sectional study, 190 sera were collected from butchers and slaughterhouse workers in different regions of the Sistan va Baluchestan province, in Iran in 2011. A questionnaire was filled for each participant to document personal and behavioural information. The sera were tested for detection of specific IgG antibodies against brucellosis, leptospirosis, and Q fever (phase I and II) using commercial enzyme-linked immunosorbent assays (ELISA). The seroprevalence of brucellosis was 7.9%, leptospirosis 23.4%, and phase I and II of Q fever were 18.1% and 14.4%, respectively. The seroprevalence of Q fever and leptospirosis, but not brucellosis, varied among regions within the province (p = 0.01). Additionally, a significant relationship was found between seropositivity of Q fever and camel slaughtering (p = 0.04). Reduced seropositivity rate of brucellosis was associated with use of personal protective equipment (PPE) (p = 0.004). This study shows that brucellosis, leptospirosis and Q fever occur among butchers and slaughterhouse workers in this area.

Robust metabolic responses to varied carbon sources in natural and laboratory strains of Saccharomyces cerevisiae.

Directory of Open Access Journals (Sweden)

Wayne A Van Voorhies

Full Text Available Understanding factors that regulate the metabolism and growth of an organism is of fundamental biologic interest. This study compared the influence of two different carbon substrates, dextrose and galactose, on the metabolic and growth rates of the yeast Saccharomyces cerevisiae. Yeast metabolic and growth rates varied widely depending on the metabolic substrate supplied. The metabolic and growth rates of a yeast strain maintained under long-term laboratory conditions was compared to strain isolated from natural condition when grown on different substrates. Previous studies had determined that there are numerous genetic differences between these two strains. However, the overall metabolic and growth rates of a wild isolate of yeast was very similar to that of a strain that had been maintained under laboratory conditions for many decades. This indicates that, at in least this case, metabolism and growth appear to be well buffered against genetic differences. Metabolic rate and cell number did not co-vary in a simple linear manner. When grown in either dextrose or galactose, both strains showed a growth pattern in which the number of cells continued to increase well after the metabolic rate began a sharp decline. Previous studied have reported that O₂ consumption in S. cerevisiae grown in reduced dextrose levels were elevated compared to higher levels. Low dextrose levels have been proposed to induce caloric restriction and increase life span in yeast. However, there was no evidence that reduced levels of dextrose increased metabolic rates, measured by either O₂ consumption or CO₂ production, in the strains used in this study.

Modeling information diffusion in time-varying community networks

Science.gov (United States)

Cui, Xuelian; Zhao, Narisa

2017-12-01

Social networks are rarely static, and they typically have time-varying network topologies. A great number of studies have modeled temporal networks and explored social contagion processes within these models; however, few of these studies have considered community structure variations. In this paper, we present a study of how the time-varying property of a modular structure influences the information dissemination. First, we propose a continuous-time Markov model of information diffusion where two parameters, mobility rate and community attractiveness, are introduced to address the time-varying nature of the community structure. The basic reproduction number is derived, and the accuracy of this model is evaluated by comparing the simulation and theoretical results. Furthermore, numerical results illustrate that generally both the mobility rate and community attractiveness significantly promote the information diffusion process, especially in the initial outbreak stage. Moreover, the strength of this promotion effect is much stronger when the modularity is higher. Counterintuitively, it is found that when all communities have the same attractiveness, social mobility no longer accelerates the diffusion process. In addition, we show that the local spreading in the advantage group has been greatly enhanced due to the agglomeration effect caused by the social mobility and community attractiveness difference, which thus increases the global spreading.

Experimental validation of the intrinsic spatial efficiency method over a wide range of sizes for cylindrical sources

Energy Technology Data Exchange (ETDEWEB)

Ortiz-Ramŕez, Pablo, E-mail: rapeitor@ug.uchile.cl; Larroquette, Philippe [Departamento de Física, Facultad de Ciencias, Universidad de Chile (Chile); Camilla, S. [Departamento de Física, Universidad Tecnológica Metropolitana (Chile)

2016-07-07

The intrinsic spatial efficiency method is a new absolute method to determine the efficiency of a gamma spectroscopy system for any extended source. In the original work the method was experimentally demonstrated and validated for homogeneous cylindrical sources containing {sup 137}Cs, whose sizes varied over a small range (29.5 mm radius and 15.0 to 25.9 mm height). In this work we present an extension of the validation over a wide range of sizes. The dimensions of the cylindrical sources vary between 10 to 40 mm height and 8 to 30 mm radius. The cylindrical sources were prepared using the reference material IAEA-372, which had a specific activity of 11320 Bq/kg at july 2006. The obtained results were better for the sources with 29 mm radius showing relative bias lesser than 5% and for the sources with 10 mm height showing relative bias lesser than 6%. In comparison with the obtained results in the work where we present the method, the majority of these results show an excellent agreement.

Overcoming Spurious Regression Using time-Varying Fourier ...

African Journals Online (AJOL)

Non-stationary time series data have been traditionally analyzed in the frequency domain by assuming constant amplitudes regardless of the timelag. A new approach called time-varying amplitude method (TVAM) is presented here. Oscillations are analyzed for changes in the magnitude of Fourier Coefficients which are ...

microwave oven-induced decalcification at varying temperatures

African Journals Online (AJOL)

Uwaifoh

2012-09-30

Sep 30, 2012 ... This study was designed to evaluate the effect of decalcifying fluid types on bone tissue architecture and its staining properties following decalcification at varying temperatures. A decalcification methodology using Golding and. Stewards (GS) fluid, and Jenkings fluid (JK), and a modern household ...

Genome-wide association genetics of an adaptive trait in lodgepole pine.

Science.gov (United States)

Parchman, Thomas L; Gompert, Zachariah; Mudge, Joann; Schilkey, Faye D; Benkman, Craig W; Buerkle, C Alex

2012-06-01

Pine cones that remain closed and retain seeds until fire causes the cones to open (cone serotiny) represent a key adaptive trait in a variety of pine species. In lodgepole pine, there is substantial geographical variation in serotiny across the Rocky Mountain region. This variation in serotiny has evolved as a result of geographically divergent selection, with consequences that extend to forest communities and ecosystems. An understanding of the genetic architecture of this trait is of interest owing to the wide-reaching ecological consequences of serotiny and also because of the repeated evolution of the trait across the genus. Here, we present and utilize an inexpensive and time-effective method for generating population genomic data. The method uses restriction enzymes and PCR amplification to generate a library of fragments that can be sequenced with a high level of multiplexing. We obtained data for more than 95,000 single nucleotide polymorphisms across 98 serotinous and nonserotinous lodgepole pines from three populations. We used a Bayesian generalized linear model (GLM) to test for an association between genotypic variation at these loci and serotiny. The probability of serotiny varied by genotype at 11 loci, and the association between genotype and serotiny at these loci was consistent in each of the three populations of pines. Genetic variation across these 11 loci explained 50% of the phenotypic variation in serotiny. Our results provide a first genome-wide association map of serotiny in pines and demonstrate an inexpensive and efficient method for generating population genomic data. © 2012 Blackwell Publishing Ltd.

Reduction operator for wide-SIMDs reconsidered

NARCIS (Netherlands)

Waeijen, L.J.W.; She, D.; Corporaal, H.; He, Y.

2014-01-01

It has been shown that wide Single Instruction Multiple Data architectures (wide-SIMDs) can achieve high energy efficiency, especially in domains such as image and vision processing. In these and various other application domains, reduction is a frequently encountered operation, where multiple input

The Three-Dimensional Velocity Distribution of Wide Gap Taylor-Couette Flow Modelled by CFD

Directory of Open Access Journals (Sweden)

David Shina Adebayo

2016-01-01

Full Text Available A numerical investigation is conducted for the flow between two concentric cylinders with a wide gap, relevant to bearing chamber applications. This wide gap configuration has received comparatively less attention than narrow gap journal bearing type geometries. The flow in the gap between an inner rotating cylinder and an outer stationary cylinder has been modelled as an incompressible flow using an implicit finite volume RANS scheme with the realisable k-ε model. The model flow is above the critical Taylor number at which axisymmetric counterrotating Taylor vortices are formed. The tangential velocity profiles at all axial locations are different from typical journal bearing applications, where the velocity profiles are quasilinear. The predicted results led to two significant findings of impact in rotating machinery operations. Firstly, the axial variation of the tangential velocity gradient induces an axially varying shear stress, resulting in local bands of enhanced work input to the working fluid. This is likely to cause unwanted heat transfer on the surface in high torque turbomachinery applications. Secondly, the radial inflow at the axial end-wall boundaries is likely to promote the transport of debris to the junction between the end-collar and the rotating cylinder, causing the build-up of fouling in the seal.

Robust and Fault-Tolerant Linear Parameter-Varying Control of Wind Turbines

DEFF Research Database (Denmark)

Sloth, Christoffer; Esbensen, Thomas; Stoustrup, Jakob

2011-01-01

High performance and reliability are required for wind turbines to be competitive within the energy market. To capture their nonlinear behavior, wind turbines are often modeled using parameter-varying models. In this paper we design and compare multiple linear parameter-varying (LPV) controllers,...

Integrated wide-band low-background amplifiers

International Nuclear Information System (INIS)

Il'yushchenko, I.I.

1980-01-01

Ways of increasing stability and reproduction of characteristics of wide-band integral amplifiers that would to the least extent increase their background noises, are discussed. Considered are some certain flowsheets of integral wide-band amplifiers with low background noise of foreign production which differ from one another by construction of inlet cascades as well as by the applied feedback type. The principal flowsheets of the amplifiers and their main performances are presented. The analysis of the data obtained has revealed that microcircuits made of cascades with a common emitter and local combined feedback are most wide-band among all the considered microcircuits [ru

IOT Overview: Wide-Field Imaging

Science.gov (United States)

Selman, F. J.

The Wide Field Imager (WFI) instrument at La Silla has been the workhorse of wide-field imaging instruments at ESO for several years. In this contribution I will summarize the issues relating to its productivity for the community both in terms of the quality and quantity of data that has come out of it. Although only surveys of limited scope have been completed using WFI, it is ESO's stepping-stone to the new generation of survey telescopes.

The utility of protein structure as a predictor of site-wise dN/dS varies widely among HIV-1 proteins.

Science.gov (United States)

Meyer, Austin G; Wilke, Claus O

2015-10-06

Protein structure acts as a general constraint on the evolution of viral proteins. One widely recognized structural constraint explaining evolutionary variation among sites is the relative solvent accessibility (RSA) of residues in the folded protein. In influenza virus, the distance from functional sites has been found to explain an additional portion of the evolutionary variation in the external antigenic proteins. However, to what extent RSA and distance from a reference site in the protein can be used more generally to explain protein adaptation in other viruses and in the different proteins of any given virus remains an open question. To address this question, we have carried out an analysis of the distribution and structural predictors of site-wise dN/dS in HIV-1. Our results indicate that the distribution of dN/dS in HIV follows a smooth gamma distribution, with no special enrichment or depletion of sites with dN/dS at or above one. The variation in dN/dS can be partially explained by RSA and distance from a reference site in the protein, but these structural constraints do not act uniformly among the different HIV-1 proteins. Structural constraints are highly predictive in just one of the three enzymes and one of three structural proteins in HIV-1. For these two proteins, the protease enzyme and the gp120 structural protein, structure explains between 30 and 40% of the variation in dN/dS. Finally, for the gp120 protein of the receptor-binding complex, we also find that glycosylation sites explain just 2% of the variation in dN/dS and do not explain gp120 evolution independently of either RSA or distance from the apical surface. © 2015 The Author(s).

Epidemiology of Coxiella burnetii infection in Africa: a OneHealth systematic review.

Directory of Open Access Journals (Sweden)

Sky Vanderburg

2014-04-01

Full Text Available Q fever is a common cause of febrile illness and community-acquired pneumonia in resource-limited settings. Coxiella burnetii, the causative pathogen, is transmitted among varied host species, but the epidemiology of the organism in Africa is poorly understood. We conducted a systematic review of C. burnetii epidemiology in Africa from a "One Health" perspective to synthesize the published data and identify knowledge gaps.We searched nine databases to identify articles relevant to four key aspects of C. burnetii epidemiology in human and animal populations in Africa: infection prevalence; disease incidence; transmission risk factors; and infection control efforts. We identified 929 unique articles, 100 of which remained after full-text review. Of these, 41 articles describing 51 studies qualified for data extraction. Animal seroprevalence studies revealed infection by C. burnetii (≤13% among cattle except for studies in Western and Middle Africa (18-55%. Small ruminant seroprevalence ranged from 11-33%. Human seroprevalence was <8% with the exception of studies among children and in Egypt (10-32%. Close contact with camels and rural residence were associated with increased seropositivity among humans. C. burnetii infection has been associated with livestock abortion. In human cohort studies, Q fever accounted for 2-9% of febrile illness hospitalizations and 1-3% of infective endocarditis cases. We found no studies of disease incidence estimates or disease control efforts.C. burnetii infection is detected in humans and in a wide range of animal species across Africa, but seroprevalence varies widely by species and location. Risk factors underlying this variability are poorly understood as is the role of C. burnetii in livestock abortion. Q fever consistently accounts for a notable proportion of undifferentiated human febrile illness and infective endocarditis in cohort studies, but incidence estimates are lacking. C. burnetii presents a real

Management van World-Wide Web Servers

NARCIS (Netherlands)

van Hengstum, F.P.H.; Pras, Aiko

1996-01-01

Het World Wide Web is een populaire Internet toepassing waarmee het mogelijk is documenten aan willekeurige Internet gebruikers aan te bieden. Omdat hiervoor nog geen voorzieningen zijn getroffen, was het tot voor kort niet goed mogelijk het World Wide Web op afstand te beheren. De Universiteit

Local tumor control and toxicity in HIV-associated anal carcinoma treated with radiotherapy in the era of antiretroviral therapy

Directory of Open Access Journals (Sweden)

Lütolf Urs M

2006-08-01

Full Text Available Abstract Purpose To investigate the outcome of HIV-seropositive patients under highly active antiretroviral treatment (HAART with anal cancer treated with radiotherapy (RT alone or in combination with standard chemotherapy (CT. Patients and methods Clinical outcome of 81 HIV-seronegative patients (1988 – 2003 and 10 consecutive HIV-seropositive patients under HAART (1997 – 2003 that were treated with 3-D conformal RT of 59.4 Gy and standard 5-fluorouracil and mitomycin-C were retrospectively analysed. 10 TNM-stage and age matched HIV-seronegative patients (1992 – 2003 were compared with the 10 HIV-seropositive patients. Pattern of care, local disease control (LC, overall survival (OS, cancer-specific survival (CSS, and toxicity were assessed. Results RT with or without CT resulted in complete response in 100 % of HIV-seropositive patients. LC was impaired compared to matched HIV-seronegative patients after a median follow-up of 44 months (p = 0.03. OS at 5 years was 70 % in HIV-seropositive patients receiving HAART and 69 % in the matched controls. Colostomy-free survival was 70 % (HIV+ and 100 % (matched HIV- and 78 % (all HIV-. No HIV-seropositive patient received an interstitial brachytherapy boost compared to 42 % of all HIV-seronegative patients and adherence to chemotherapy seemed to be difficult in HIV-seropositive patients. Acute hematological toxicity reaching 50 % was high in HIV-seropositive patients receiving MMC compared with 0 % in matched HIV-seronegative patients (p = 0.05 or 12 % in all HIV-seronegative patients. The rate of long-term side effects was low in HIV-seropositive patients. Conclusion Despite high response rates to organ preserving treatment with RT with or without CT, local tumor failure seems to be high in HIV-positive patients receiving HAART. HIV-seropositive patients are subject to treatment bias, being less likely treated with interstitial brachytherapy boost probably due to HIV-infection, and they are at

GB Virus C (GBV-C Infection in Hepatitis C Virus (HCV Seropositive Women with or at Risk for HIV Infection.

Directory of Open Access Journals (Sweden)

Jason T Blackard

Full Text Available GB virus C (GBV-C may have a beneficial impact on HIV disease progression; however, the epidemiologic characteristics of this virus are not well characterized. Behavioral factors and gender may lead to differential rates of GBV-C infection; yet, studies have rarely addressed GBV-C infections in women or racial/ethnic minorities. Therefore, we evaluated GBV-C RNA prevalence and genotype distribution in a large prospective study of high-risk women in the US.438 hepatitis C virus (HCV seropositive women, including 306 HIV-infected and 132 HIV-uninfected women, from the HIV Epidemiologic Research Study were evaluated for GBV-C RNA. 347 (79.2% women were GBV-C RNA negative, while 91 (20.8% were GBV-C RNA positive. GBV-C positive women were younger than GBV-C negative women. Among 306 HIV-infected women, 70 (22.9% women were HIV/GBV-C co-infected. Among HIV-infected women, the only significant difference between GBV-negative and GBV-positive women was age (mean 38.4 vs. 35.1 years; p<0.001. Median baseline CD4 cell counts and plasma HIV RNA levels were similar. The GBV-C genotypes were 1 (n = 31; 44.3%, 2 (n = 36; 51.4%, and 3 (n = 3; 4.3%. The distribution of GBV-C genotypes in co-infected women differed significantly by race/ethnicity. However, median CD4 cell counts and log10 HIV RNA levels did not differ by GBV-C genotype. GBV-C incidence was 2.7% over a median follow-up of 2.9 (IQR: 1.5, 4.9 years, while GBV-C clearance was 35.7% over a median follow-up of 2.44 (1.4, 3.5 years. 4 women switched genotypes.Age, injection drug use, a history of sex for money or drugs, and number of recent male sex partners were associated with GBV-C infection among all women in this analysis. However, CD4 cell count and HIV viral load of HIV/HCV/GBV-C co-infected women were not different although race was associated with GBV-C genotype.

Incipient Fault Detection for Rolling Element Bearings under Varying Speed Conditions.

Science.gov (United States)

Xue, Lang; Li, Naipeng; Lei, Yaguo; Li, Ningbo

2017-06-20

Varying speed conditions bring a huge challenge to incipient fault detection of rolling element bearings because both the change of speed and faults could lead to the amplitude fluctuation of vibration signals. Effective detection methods need to be developed to eliminate the influence of speed variation. This paper proposes an incipient fault detection method for bearings under varying speed conditions. Firstly, relative residual (RR) features are extracted, which are insensitive to the varying speed conditions and are able to reflect the degradation trend of bearings. Then, a health indicator named selected negative log-likelihood probability (SNLLP) is constructed to fuse a feature set including RR features and non-dimensional features. Finally, based on the constructed SNLLP health indicator, a novel alarm trigger mechanism is designed to detect the incipient fault. The proposed method is demonstrated using vibration signals from bearing tests and industrial wind turbines. The results verify the effectiveness of the proposed method for incipient fault detection of rolling element bearings under varying speed conditions.

Wide Bandgap Extrinsic Photoconductive Switches

Energy Technology Data Exchange (ETDEWEB)

Sullivan, James S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2013-07-03

Semi-insulating Gallium Nitride, 4H and 6H Silicon Carbide are attractive materials for compact, high voltage, extrinsic, photoconductive switches due to their wide bandgap, high dark resistance, high critical electric field strength and high electron saturation velocity. These wide bandgap semiconductors are made semi-insulating by the addition of vanadium (4H and 6HSiC) and iron (2H-GaN) impurities that form deep acceptors. These deep acceptors trap electrons donated from shallow donor impurities. The electrons can be optically excited from these deep acceptor levels into the conduction band to transition the wide bandgap semiconductor materials from a semi-insulating to a conducting state. Extrinsic photoconductive switches with opposing electrodes have been constructed using vanadium compensated 6H-SiC and iron compensated 2H-GaN. These extrinsic photoconductive switches were tested at high voltage and high power to determine if they could be successfully used as the closing switch in compact medical accelerators.

Scaling properties in time-varying networks with memory

Science.gov (United States)

Kim, Hyewon; Ha, Meesoon; Jeong, Hawoong

2015-12-01

The formation of network structure is mainly influenced by an individual node's activity and its memory, where activity can usually be interpreted as the individual inherent property and memory can be represented by the interaction strength between nodes. In our study, we define the activity through the appearance pattern in the time-aggregated network representation, and quantify the memory through the contact pattern of empirical temporal networks. To address the role of activity and memory in epidemics on time-varying networks, we propose temporal-pattern coarsening of activity-driven growing networks with memory. In particular, we focus on the relation between time-scale coarsening and spreading dynamics in the context of dynamic scaling and finite-size scaling. Finally, we discuss the universality issue of spreading dynamics on time-varying networks for various memory-causality tests.

Time-Varying Networks of Inter-Ictal Discharging Reveal Epileptogenic Zone.

Science.gov (United States)

Zhang, Luyan; Liang, Yi; Li, Fali; Sun, Hongbin; Peng, Wenjing; Du, Peishan; Si, Yajing; Song, Limeng; Yu, Liang; Xu, Peng

2017-01-01

The neuronal synchronous discharging may cause an epileptic seizure. Currently, most of the studies conducted to investigate the mechanism of epilepsy are based on EEGs or functional magnetic resonance imaging (fMRI) recorded during the ictal discharging or the resting-state, and few studies have probed into the dynamic patterns during the inter-ictal discharging that are much easier to record in clinical applications. Here, we propose a time-varying network analysis based on adaptive directed transfer function to uncover the dynamic brain network patterns during the inter-ictal discharging. In addition, an algorithm based on the time-varying outflow of information derived from the network analysis is developed to detect the epileptogenic zone. The analysis performed revealed the time-varying network patterns during different stages of inter-ictal discharging; the epileptogenic zone was activated prior to the discharge onset then worked as the source to propagate the activity to other brain regions. Consistence between the epileptogenic zones detected by our proposed approach and the actual epileptogenic zones proved that time-varying network analysis could not only reveal the underlying neural mechanism of epilepsy, but also function as a useful tool in detecting the epileptogenic zone based on the EEGs in the inter-ictal discharging.

Progress on MEVVA source VARIS at GSI

Science.gov (United States)

Adonin, A.; Hollinger, R.

2018-05-01

For the last few years, the development of the VARIS (vacuum arc ion source) was concentrated on several aspects. One of them was the production of high current ion beams of heavy metals such as Au, Pb, and Bi. The requested ion charge state for these ion species is 4+. This is quite challenging to produce in vacuum arc driven sources for reasonable beam pulse length (>120 µs) due to the physical properties of these elements. However, the situation can be dramatically improved by using the composite materials or alloys with enhanced physical properties of the cathodes. Another aspect is an increase of the beam brilliance for intense U4+ beams by the optimization of the geometry of the extraction system. A new 7-hole triode extraction system allows an increase of the extraction voltage from 30 kV to 40 kV and also reduces the outer aperture of the extracted ion beam. Thus, a record beam brilliance for the U4+ beam in front of the RFQ (Radio-Frequency Quadrupole) has been achieved, exceeding the RFQ space charge limit for an ion current of 15 mA. Several new projectiles in the middle-heavy region have been successfully developed from VARIS to fulfill the requirements of the future FAIR (Facility for Antiproton and Ion Research) programs. An influence of an auxiliary gas on the production performance of certain ion charge states as well as on operation stability has been investigated. The optimization of the ion source parameters for a maximum production efficiency and highest particle current in front of the RFQ has been performed. The next important aspect of the development will be the increase of the operation repetition rate of VARIS for all elements especially for uranium to 2.7 Hz in order to provide the maximum availability of high current ion beams for future FAIR experiments.

Wide gap semiconductor microwave devices

International Nuclear Information System (INIS)

Buniatyan, V V; Aroutiounian, V M

2007-01-01

A review of properties of wide gap semiconductor materials such as diamond, diamond-like carbon films, SiC, GaP, GaN and AlGaN/GaN that are relevant to electronic, optoelectronic and microwave applications is presented. We discuss the latest situation and perspectives based on experimental and theoretical results obtained for wide gap semiconductor devices. Parameters are taken from the literature and from some of our theoretical works. The correspondence between theoretical results and parameters of devices is critically analysed. (review article)

Modelling seasonal habitat suitability for wide-ranging species: Invasive wild pigs in northern Australia.

Directory of Open Access Journals (Sweden)

Jens G Froese

Full Text Available Invasive wildlife often causes serious damage to the economy and agriculture as well as environmental, human and animal health. Habitat models can fill knowledge gaps about species distributions and assist planning to mitigate impacts. Yet, model accuracy and utility may be compromised by small study areas and limited integration of species ecology or temporal variability. Here we modelled seasonal habitat suitability for wild pigs, a widespread and harmful invader, in northern Australia. We developed a resource-based, spatially-explicit and regional-scale approach using Bayesian networks and spatial pattern suitability analysis. We integrated important ecological factors such as variability in environmental conditions, breeding requirements and home range movements. The habitat model was parameterized during a structured, iterative expert elicitation process and applied to a wet season and a dry season scenario. Model performance and uncertainty was evaluated against independent distributional data sets. Validation results showed that an expert-averaged model accurately predicted empirical wild pig presences in northern Australia for both seasonal scenarios. Model uncertainty was largely associated with different expert assumptions about wild pigs' resource-seeking home range movements. Habitat suitability varied considerably between seasons, retracting to resource-abundant rainforest, wetland and agricultural refuge areas during the dry season and expanding widely into surrounding grassland floodplains, savanna woodlands and coastal shrubs during the wet season. Overall, our model suggested that suitable wild pig habitat is less widely available in northern Australia than previously thought. Mapped results may be used to quantify impacts, assess risks, justify management investments and target control activities. Our methods are applicable to other wide-ranging species, especially in data-poor situations.

Insights from LGI1 and CASPR2 potassium channel complex autoantibody subtyping.

Science.gov (United States)

Klein, Christopher J; Lennon, Vanda A; Aston, Paula A; McKeon, Andrew; O'Toole, Orna; Quek, Amy; Pittock, Sean J

2013-02-01

To determine, in patients identified as seropositive for neuronal voltage-gated potassium channel (VGKC) complex autoantibodies, the spectrum of clinical presentations and frequency of leucine-rich glioma-inactivated protein 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) as defined antigenic neuronal targets in the VGKC macromolecular complex. Retrospective cohort study. Clinical practice, Mayo Clinic Neuroimmunology Laboratory and Department of Neurology. A total of 54 853 patients were evaluated, of whom 1992 were found to be VGKC complex IgG positive. From June 1, 2008, to June 30, 2010, comprehensive service serologic evaluation performed on 54853 patients with unexplained neurologic symptoms identified 1992 patients (4%) who were positive for VGKC complex IgG (values ≥ 0.03 nmol/L). Among 316 seropositive patients evaluated clinically at our institution, 82 (26%) were seropositive for LGI1 IgG and/or CASPR2 IgG. Of these 82 patients, 27% had low (0.03-0.09 nmol/L), 51% had medium (0.10-0.99 nmol/L), and 22% had high (≥ 1.00 nmol/L) VGKC complex IgG values. Leucine-rich glioma-inactivated protein 1 IgG positivity was associated with higher VGKC complex IgG values (PVGKC complex IgG values and varying LGI1 IgG and CASPR2 IgG specificities. The frequent occurrence of LGI1 IgG and CASPR2 IgG in serum samples with low and medium VGKC complex IgG values supports the clinical significance of low values in clinical evaluation. Additional antigenic components of VGKC macromolecular complexes remain to be defined.

Perturbation methods and the Melnikov functions for slowly varying oscillators

International Nuclear Information System (INIS)

Lakrad, Faouzi; Charafi, Moulay Mustapha

2005-01-01

A new approach to obtaining the Melnikov function for homoclinic orbits in slowly varying oscillators is proposed. The present method applies the Lindstedt-Poincare method to determine an approximation of homoclinic solutions. It is shown that the resultant Melnikov condition is the same as that obtained in the usual way involving distance functions in three dimensions by Wiggins and Holmes [Homoclinic orbits in slowly varying oscillators. SIAM J Math Anal 1987;18(3):612

Quantum capacity under adversarial quantum noise: arbitrarily varying quantum channels

OpenAIRE

Ahlswede, Rudolf; Bjelakovic, Igor; Boche, Holger; Noetzel, Janis

2010-01-01

We investigate entanglement transmission over an unknown channel in the presence of a third party (called the adversary), which is enabled to choose the channel from a given set of memoryless but non-stationary channels without informing the legitimate sender and receiver about the particular choice that he made. This channel model is called arbitrarily varying quantum channel (AVQC). We derive a quantum version of Ahlswede's dichotomy for classical arbitrarily varying channels. This includes...

Innovation in Science Education - World-Wide.

Science.gov (United States)

Baez, Albert V.

The purpose of this book is to promote improvements in science education, world-wide, but particularly in developing countries. It is addressed to those in positions to make effective contributions to the improvement of science education. The world-wide role of science education, the goals of innovative activities, past experience in efforts to…

Regionally-varying and regionally-uniform electricity pricing policies compared across four usage categories

International Nuclear Information System (INIS)

Cho, Seong-Hoon; Kim, Taeyoung; Kim, Hyun Jae; Park, Kihyun; Roberts, Roland K.

2015-01-01

The objective of our research is to predict how electricity demand varies spatially between status quo regionally-uniform electricity pricing and hypothetical regionally-varying electricity pricing across usage categories. We summarize the empirical results of a case study of electricity demand in South Korea with three key findings and their related implications. First, the price elasticities of electricity demand differ across usage categories. Specifically, electricity demands for manufacturing and retail uses are price inelastic and close to unit elastic, respectively, while those for agricultural and residential uses are not statistically significant. This information is important in designing energy policy, because higher electricity prices could reduce electricity demands for manufacturing and retail uses, resulting in slower growth in those sectors. Second, spatial spillovers in electricity demand vary across uses. Understanding the spatial structure of electricity demand provides useful information to energy policy makers for anticipating changes in demand across regions via regionally-varying electricity pricing for different uses. Third, simulation results suggest that spatial variations among electricity demands by usage category under a regionally-varying electricity-pricing policy differ from those under a regionally-uniform electricity-pricing policy. Differences in spatial changes between the policies provide information for developing a realistic regionally-varying electricity-pricing policy according to usage category. - Highlights: • We compare regionally-varying and regionally-uniform electricity pricing policies. • We summarize empirical results of a case study of electricity demand in South Korea. • We confirm that spatial spillovers in electricity demands vary across different uses. • We find positive spatial spillovers in the manufacturing and residential sectors. • Our methods help policy makers evaluate regionally-varying pricing

World Wide Web of Your Wide Web? Juridische aspecten van zoekmachine-personalisatie

NARCIS (Netherlands)

Oostveen, M.

2012-01-01

Het world wide web is een enorme bron van informatie. Iedere internetgebruiker maakt gebruik van zoekmachines om die informatie te kunnen vinden. Veel gebruikers weten echter niet dat zoekresultaten behorende bij een bepaalde zoekterm niet voor iedereen hetzelfde zijn. Dit personaliseren van

Donor cytomegalovirus status influences the outcome of allogeneic stem cell transplant: a study by the European group for blood and marrow transplantation.

Science.gov (United States)

Ljungman, Per; Brand, Ronald; Hoek, Jennifer; de la Camara, Rafael; Cordonnier, Catherine; Einsele, Hermann; Styczynski, Jan; Ward, Katherine N; Cesaro, Simone

2014-08-15

The use of a cytomegalovirus (CMV)-seronegative donor for a CMV-seronegative allogeneic hematopoietic stem cell transplant (HSCT) recipient is generally accepted. However, the importance of donor serostatus in CMV-seropositive patients is controversial. A total of 49 542 HSCT patients, 29 349 seropositive and 20 193 seronegative, were identified from the European Group for Blood and Marrow Transplantation database. Cox multivariate models were fitted to estimate the effect of donor CMV serological status on outcome. Seronegative patients receiving seropositive unrelated-donor grafts had decreased overall survival (hazard ratio [HR], 1.13; 95% confidence interval [CI], 1.06-1.21; P donors, whereas no difference was seen in patients receiving HLA-matched sibling grafts. Seropositive patients receiving grafts from seropositive unrelated donors had improved overall survival (HR, 0.92; 95% CI, .86-.98; P donors, if they had received myeloablative conditioning. This effect was absent when they received reduced-intensity conditioning. No effect was seen in patients grafted from HLA-identical sibling donors. The same association was found if the study was limited to patients receiving transplants from the year 2000 onward. We confirm the negative impact on overall survival if a CMV-seropositive unrelated donor is selected for a CMV-seronegative patient. For a CMV-seropositive patient, our data support selecting a CMV-seropositive donor if the patient receives a myeloablative conditioning regimen. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

From Genome-Wide Association Study to Phenome-Wide Association Study: New Paradigms in Obesity Research.

Science.gov (United States)

Zhang, Y-P; Zhang, Y-Y; Duan, D D

2016-01-01

Obesity is a condition in which excess body fat has accumulated over an extent that increases the risk of many chronic diseases. The current clinical classification of obesity is based on measurement of body mass index (BMI), waist-hip ratio, and body fat percentage. However, these measurements do not account for the wide individual variations in fat distribution, degree of fatness or health risks, and genetic variants identified in the genome-wide association studies (GWAS). In this review, we will address this important issue with the introduction of phenome, phenomics, and phenome-wide association study (PheWAS). We will discuss the new paradigm shift from GWAS to PheWAS in obesity research. In the era of precision medicine, phenomics and PheWAS provide the required approaches to better definition and classification of obesity according to the association of obese phenome with their unique molecular makeup, lifestyle, and environmental impact. Copyright © 2016 Elsevier Inc. All rights reserved.

World-Wide Web: The Information Universe.

Science.gov (United States)

Berners-Lee, Tim; And Others

1992-01-01

Describes the World-Wide Web (W3) project, which is designed to create a global information universe using techniques of hypertext, information retrieval, and wide area networking. Discussion covers the W3 data model, W3 architecture, the document naming scheme, protocols, document formats, comparison with other systems, experience with the W3…

Evaporation monitoring and composition control of alloy systems with widely differing vapor pressures

International Nuclear Information System (INIS)

Anklam, T.M.; Berzins, L.V.; Braun, D.G.; Haynam, C.; McClelland, M.A.; Meier, T.

1994-10-01

Lawrence Livermore National Laboratory is developing sensors and controls to improve and extend electron beam materials processing technology to alloy systems with constituents of widely varying vapor pressure. The approach under development involves using tunable lasers to measure the density and composition of the vapor plume. A laser based vaporizer control system for vaporization of a uranium-iron alloy has been previously demonstrated in multi-hundred hour, high rate vaporization experiments at LLNL. This paper reviews the design and performance of the uranium vaporization sensor and control system and discusses the extension of the technology to monitoring of uranium vaporization. Data is presented from an experiment in which titanium wire was fed into a molten niobium pool. Laser data is compared to deposited film composition and film cross sections. Finally, the potential for using this technique for composition control in melting applications is discussed

Costs of fear: Behavioral and life-history responses to risk and their demographic consequences vary across species

Science.gov (United States)

LaManna, Joseph A.; Martin, Thomas E.

2016-01-01

Behavioural responses to reduce predation risk might cause demographic ‘costs of fear’. Costs differ among species, but a conceptual framework to understand this variation is lacking. We use a life-history framework to tie together diverse traits and life stages to better understand interspecific variation in responses and costs. We used natural and experimental variation in predation risk to test phenotypic responses and associated demographic costs for 10 songbird species. Responses such as increased parental attentiveness yielded reduced development time and created benefits such as reduced predation probability. Yet, responses to increased risk also created demographic costs by reducing offspring production in the absence of direct predation. This cost of fear varied widely across species, but predictably with the probability of repeat breeding. Use of a life-history framework can aid our understanding of potential demographic costs from predation, both from responses to perceived risk and from direct predation mortality.

Flexible time-varying filter banks

Science.gov (United States)

Tuncer, Temel E.; Nguyen, Truong Q.

1993-09-01

Linear phase maximally flat FIR Butterworth filter approximations are discussed and a new filter design method is introduced. This variable cutoff filter design method uses the cosine modulated versions of a prototype filter. The design procedure is simple and different variants of this procedure can be used to obtain close to optimum linear phase filters. Using this method, flexible time-varying filter banks with good reconstruction error are introduced. These types of oversampled filter banks have small magnitude error which can be easily controlled by the appropriate choice of modulation frequency. This error can be further decreased by magnitude equalization without increasing the computational complexity considerably. Two dimensional design examples are also given.

Investigating Time-Varying Drivers of Grid Project Emissions Impacts

Energy Technology Data Exchange (ETDEWEB)

Barrett, Emily L.; Thayer, Brandon L.; Pal, Seemita; Studarus, Karen E.

2017-11-15

The emissions consequences of smart grid technologies depend heavily on their context and vary not only by geographical location, but by time of year. The same technology operated to meet the same objective may increase the emissions associated with energy generation for part of the year and decrease emissions during other times. The Grid Project Impact Quantification (GridPIQ) tool provides the ability to estimate these seasonal variations and garner insight into the time-varying drivers of grid project emissions impacts. This work leverages GridPIQ to examine the emissions implications across years and seasons of adding energy storage technology to reduce daily peak demand in California and New York.

Test Review for Preschool-Wide Evaluation Tool (PreSET) Manual: Assessing Universal Program-Wide Positive Behavior Support in Early Childhood

Science.gov (United States)

Rodriguez, Billie Jo

2013-01-01

The Preschool-Wide Evaluation Tool (PreSET; Steed & Pomerleau, 2012) is published by Paul H. Brookes Publishing Company in Baltimore, MD. The PreSET purports to measure universal and program-wide features of early childhood programs' implementation fidelity of program-wide positive behavior intervention and support (PW-PBIS) and is,…

A method for fitting regression splines with varying polynomial order in the linear mixed model.

Science.gov (United States)

Edwards, Lloyd J; Stewart, Paul W; MacDougall, James E; Helms, Ronald W

2006-02-15

The linear mixed model has become a widely used tool for longitudinal analysis of continuous variables. The use of regression splines in these models offers the analyst additional flexibility in the formulation of descriptive analyses, exploratory analyses and hypothesis-driven confirmatory analyses. We propose a method for fitting piecewise polynomial regression splines with varying polynomial order in the fixed effects and/or random effects of the linear mixed model. The polynomial segments are explicitly constrained by side conditions for continuity and some smoothness at the points where they join. By using a reparameterization of this explicitly constrained linear mixed model, an implicitly constrained linear mixed model is constructed that simplifies implementation of fixed-knot regression splines. The proposed approach is relatively simple, handles splines in one variable or multiple variables, and can be easily programmed using existing commercial software such as SAS or S-plus. The method is illustrated using two examples: an analysis of longitudinal viral load data from a study of subjects with acute HIV-1 infection and an analysis of 24-hour ambulatory blood pressure profiles.

A New Time-varying Concept of Risk in a Changing Climate

Science.gov (United States)

Sarhadi, Ali; Ausín, María Concepción; Wiper, Michael P.

2016-10-01

In a changing climate arising from anthropogenic global warming, the nature of extreme climatic events is changing over time. Existing analytical stationary-based risk methods, however, assume multi-dimensional extreme climate phenomena will not significantly vary over time. To strengthen the reliability of infrastructure designs and the management of water systems in the changing environment, multidimensional stationary risk studies should be replaced with a new adaptive perspective. The results of a comparison indicate that current multi-dimensional stationary risk frameworks are no longer applicable to projecting the changing behaviour of multi-dimensional extreme climate processes. Using static stationary-based multivariate risk methods may lead to undesirable consequences in designing water system infrastructures. The static stationary concept should be replaced with a flexible multi-dimensional time-varying risk framework. The present study introduces a new multi-dimensional time-varying risk concept to be incorporated in updating infrastructure design strategies under changing environments arising from human-induced climate change. The proposed generalized time-varying risk concept can be applied for all stochastic multi-dimensional systems that are under the influence of changing environments.

A New Time-varying Concept of Risk in a Changing Climate.

Science.gov (United States)

Sarhadi, Ali; Ausín, María Concepción; Wiper, Michael P

2016-10-20

In a changing climate arising from anthropogenic global warming, the nature of extreme climatic events is changing over time. Existing analytical stationary-based risk methods, however, assume multi-dimensional extreme climate phenomena will not significantly vary over time. To strengthen the reliability of infrastructure designs and the management of water systems in the changing environment, multidimensional stationary risk studies should be replaced with a new adaptive perspective. The results of a comparison indicate that current multi-dimensional stationary risk frameworks are no longer applicable to projecting the changing behaviour of multi-dimensional extreme climate processes. Using static stationary-based multivariate risk methods may lead to undesirable consequences in designing water system infrastructures. The static stationary concept should be replaced with a flexible multi-dimensional time-varying risk framework. The present study introduces a new multi-dimensional time-varying risk concept to be incorporated in updating infrastructure design strategies under changing environments arising from human-induced climate change. The proposed generalized time-varying risk concept can be applied for all stochastic multi-dimensional systems that are under the influence of changing environments.

Lyapunov Functions to Caputo Fractional Neural Networks with Time-Varying Delays

Directory of Open Access Journals (Sweden)

Ravi Agarwal

2018-05-01

Full Text Available One of the main properties of solutions of nonlinear Caputo fractional neural networks is stability and often the direct Lyapunov method is used to study stability properties (usually these Lyapunov functions do not depend on the time variable. In connection with the Lyapunov fractional method we present a brief overview of the most popular fractional order derivatives of Lyapunov functions among Caputo fractional delay differential equations. These derivatives are applied to various types of neural networks with variable coefficients and time-varying delays. We show that quadratic Lyapunov functions and their Caputo fractional derivatives are not applicable in some cases when one studies stability properties. Some sufficient conditions for stability of equilibrium of nonlinear Caputo fractional neural networks with time dependent transmission delays, time varying self-regulating parameters of all units and time varying functions of the connection between two neurons in the network are obtained. The cases of time varying Lipschitz coefficients as well as nonLipschitz activation functions are studied. We illustrate our theory on particular nonlinear Caputo fractional neural networks.

Incipient Fault Detection for Rolling Element Bearings under Varying Speed Conditions

Directory of Open Access Journals (Sweden)

Lang Xue

2017-06-01

Full Text Available Varying speed conditions bring a huge challenge to incipient fault detection of rolling element bearings because both the change of speed and faults could lead to the amplitude fluctuation of vibration signals. Effective detection methods need to be developed to eliminate the influence of speed variation. This paper proposes an incipient fault detection method for bearings under varying speed conditions. Firstly, relative residual (RR features are extracted, which are insensitive to the varying speed conditions and are able to reflect the degradation trend of bearings. Then, a health indicator named selected negative log-likelihood probability (SNLLP is constructed to fuse a feature set including RR features and non-dimensional features. Finally, based on the constructed SNLLP health indicator, a novel alarm trigger mechanism is designed to detect the incipient fault. The proposed method is demonstrated using vibration signals from bearing tests and industrial wind turbines. The results verify the effectiveness of the proposed method for incipient fault detection of rolling element bearings under varying speed conditions.

New Inference Procedures for Semiparametric Varying-Coefficient Partially Linear Cox Models

Directory of Open Access Journals (Sweden)

Yunbei Ma

2014-01-01

Full Text Available In biomedical research, one major objective is to identify risk factors and study their risk impacts, as this identification can help clinicians to both properly make a decision and increase efficiency of treatments and resource allocation. A two-step penalized-based procedure is proposed to select linear regression coefficients for linear components and to identify significant nonparametric varying-coefficient functions for semiparametric varying-coefficient partially linear Cox models. It is shown that the penalized-based resulting estimators of the linear regression coefficients are asymptotically normal and have oracle properties, and the resulting estimators of the varying-coefficient functions have optimal convergence rates. A simulation study and an empirical example are presented for illustration.

Assumption-free estimation of heritability from genome-wide identity-by-descent sharing between full siblings.

Directory of Open Access Journals (Sweden)

2006-03-01

Full Text Available The study of continuously varying, quantitative traits is important in evolutionary biology, agriculture, and medicine. Variation in such traits is attributable to many, possibly interacting, genes whose expression may be sensitive to the environment, which makes their dissection into underlying causative factors difficult. An important population parameter for quantitative traits is heritability, the proportion of total variance that is due to genetic factors. Response to artificial and natural selection and the degree of resemblance between relatives are all a function of this parameter. Following the classic paper by R. A. Fisher in 1918, the estimation of additive and dominance genetic variance and heritability in populations is based upon the expected proportion of genes shared between different types of relatives, and explicit, often controversial and untestable models of genetic and non-genetic causes of family resemblance. With genome-wide coverage of genetic markers it is now possible to estimate such parameters solely within families using the actual degree of identity-by-descent sharing between relatives. Using genome scans on 4,401 quasi-independent sib pairs of which 3,375 pairs had phenotypes, we estimated the heritability of height from empirical genome-wide identity-by-descent sharing, which varied from 0.374 to 0.617 (mean 0.498, standard deviation 0.036. The variance in identity-by-descent sharing per chromosome and per genome was consistent with theory. The maximum likelihood estimate of the heritability for height was 0.80 with no evidence for non-genetic causes of sib resemblance, consistent with results from independent twin and family studies but using an entirely separate source of information. Our application shows that it is feasible to estimate genetic variance solely from within-family segregation and provides an independent validation of previously untestable assumptions. Given sufficient data, our new paradigm will

Wide-band all-angle acoustic self-collimation by rectangular sonic crystals with elliptical bases

International Nuclear Information System (INIS)

Cicek, Ahmet; Kaya, Olgun Adem; Ulug, Bulent

2011-01-01

Self-collimation of acoustic waves in the whole angular range of ±90 0 in the second and third bands of a two-dimensional rectangular sonic crystal with elliptical basis is demonstrated by examining the band structure and equifrequency contours. 70% and 77% of the second and third bands are available for wide-band all-angle self-collimation spanning a bandwidth of approximately 29% and 25% of the central frequencies of the all-angle self-collimation frequency ranges, respectively. Self-collimation of waves over large distances with a small divergence of beam width in the transverse direction is demonstrated through computations based on the finite element method. The second and third bands available for self-collimation are seen to vary linearly in the vast mid-range where a small group velocity dispersion prevents temporal divergence of waves with different frequencies.

Community wide interventions for increasing physical activity.

Science.gov (United States)

Baker, Philip R A; Francis, Daniel P; Soares, Jesus; Weightman, Alison L; Foster, Charles

2015-01-05

interventions were limited and varied. Although numerous studies have been undertaken, there is a noticeable inconsistency of the findings in the available studies and this is confounded by serious methodological issues within the included studies. The body of evidence in this review does not support the hypothesis that the multi-component community wide interventions studied effectively increased physical activity for the population, although some studies with environmental components observed more people walking.

Flexible Demand Management under Time-Varying Prices

Science.gov (United States)

Liang, Yong

In this dissertation, the problem of flexible demand management under time-varying prices is studied. This generic problem has many applications, which usually have multiple periods in which decisions on satisfying demand need to be made, and prices in these periods are time-varying. Examples of such applications include multi-period procurement problem, operating room scheduling, and user-end demand scheduling in the Smart Grid, where the last application is used as the main motivating story throughout the dissertation. The current grid is experiencing an upgrade with lots of new designs. What is of particular interest is the idea of passing time-varying prices that reflect electricity market conditions to end users as incentives for load shifting. One key component, consequently, is the demand management system at the user-end. The objective of the system is to find the optimal trade-off between cost saving and discomfort increment resulted from load shifting. In this dissertation, we approach this problem from the following aspects: (1) construct a generic model, solve for Pareto optimal solutions, and analyze the robust solution that optimizes the worst-case payoffs, (2) extend to a distribution-free model for multiple types of demand (appliances), for which an approximate dynamic programming (ADP) approach is developed, and (3) design other efficient algorithms for practical purposes of the flexible demand management system. We first construct a novel multi-objective flexible demand management model, in which there are a finite number of periods with time-varying prices, and demand arrives in each period. In each period, the decision maker chooses to either satisfy or defer outstanding demand to minimize costs and discomfort over a certain number of periods. We consider both the deterministic model, models with stochastic demand or prices, and when only partial information about the stochastic demand or prices is known. We first analyze the stochastic

Electromagnetic radiation in a time-varying background medium

NARCIS (Netherlands)

Budko, N.V.

2009-01-01

Analytical solutions are presented for the electromagnetic radiation by an arbitrary pulsed source into a homogeneous time-varying background medium. In the constant-impedance case an explicit radiation formula is obtained for the synchronous permittivity and permeability described by any positive

Karlovy Varys linastub kaks Eesti filmi / Andris Feldmanis

Index Scriptorium Estoniae

Feldmanis, Andris, 1982-

2007-01-01

Ilmar Raagi mängufilm "Klass" osaleb 42. Karlovy Vary rahvusvahelise filmifestivali võistlusprogrammis "East of the West" ja Asko Kase lühimängufilm "Zen läbi prügi" on valitud festivali kõrvalprogrammi "Forum of Independents"

River adjustments under varying flow and sediment sypply regimes. The role of hydrograh shape

Science.gov (United States)

Ferrer-Boix, C.; Elgueta, M. A.; Hassan, M. A.

2016-12-01

This research aims to explore how sediment supply conditions and hydrograph shape influence bed surface evolution, vertical and downstream sediment sorting, and sediment transport in gravel bed streams. While a significant body of research has been focused on channel evolution under constant flow regimes, few studies have focused on the impacts of flow variations in channel adjustments. Particularly, we are interested in examining the impact of the sediment supply regime and hydrograph magnitude and duration on channel adjustments and sediment transport rates. To this end, we conducted a set of experiments in a 0.8 m-wide, 5 m-long tilting flume. Flow discharge during the runs was increased and decreased at steps of certain duration allowing us to vary the steepness of rising and falling limbs of hydrographs. The influence of hydrograph shape (symmetrical and asymmetrical) on river morphodynamics was tested. Flow rates during the experiments ranged from 30 l/s to 70 l/s. Some of the experiments were conducted under no feed conditions while others were carried out with sediment supply, which ranged from 10 kg/h to 80 kg/h. The feed texture in these latter runs was identical to that of the original mixture (Dmin = 0.5 mm, Dmax = 64 mm, Dg = 5.65 mm and σg = 3.05). Initial bed slope and surface configuration were obtained after varying times of conditioning under constant flow and no feed. Finally, we conducted equilibrium experiments under constant flow and sediment supply that were used as reference. All these sets of experiments benefited from a very detailed and extensive data monitoring which allowed us to provide a unique description or river adjustments under varying flow conditions. Data acquisition included: 1) bed surface images covering the entire flume, 2) bed scans at 2 mm resolution of the whole flume and 3) real-time measurements of bedload transport (rate and texture) at the outlet of the flume. This set up allows us to obtain fractional particle

Epidemiology of Hantavirus Infections in the United States

Science.gov (United States)

1991-06-08

Hantaviruses (Family Bunyaviridae) are the etiological agents responsible for a spectrum of illnesses referred to collectively as hemorrhagic fever with...seropositives without chronic disease, one was admitted for severe preeclampsia , one for a psychiatric disorder, and three for complications from their...there was a marked difference between seropositives and seronegatives in the presumed etiology of renal disease (Table 7, Appendix 2). Seropositives had

Economics of area-wide pest control

International Nuclear Information System (INIS)

Mumford, J.D.

2000-01-01

Area-wide pest management is commonly practised throughout the world, probably much more so than is generally recognised (Lindquist 2000, Klassen 2000). Apart from highly publicised area-wide schemes such as the sterile insect technique (SIT) for fruit flies, pheromone disruption for cotton bollworms and classical biological control, there are many examples of actions such as concerted host plant eradication, enforced closed crop seasons, organised pesticide rotation for resistance management, coordination of resistant crop genotypes, etc., some going back several centuries, which should also be considered as area-wide practices. Each of these is faced with many of the economic issues generally associated with area-wide management which will be discussed below. In general, there are to be four major questions to answer in devising an area-wide pest management programme: 1) Should a particular pest be controlled locally or area-wide? 2) What is an appropriate area over which management should be attempted? 3) Within that area what form of control is most efficient? 4) What level of organisation should be used to get the job done? It should be noted that apart from clearly objective measures such as technical effectiveness (say, mortality) or cost efficiency (mortality per dollar), there are many subjective measures that come into the evaluation of area-wide control due to the element of risk (for example, in quarantine and eradication), the boundaries of externalities (for example, variable probabilities of pesticide drift under different conditions or target organism sensitivities) and time preferences for returns on capital investments (such as insect rearing facilities or research to develop pheromone technologies). As a result of these subjective components, it may sometimes be difficult to reach clearly agreed decisions based on objective economic analyses, even with a consensus on the data used. There are three general classes of economic problems in comparing

Seroadaptive Behaviors of Men Who Have Sex with Men in Myanmar.

Science.gov (United States)

Aung, Tin; Thein, Si Thu; McFarland, Willi

2016-12-01

Serosorting (i.e., choosing partners of the same HIV serostatus to reduce the risk of transmission with unprotected sex) and other forms of seroadaptation (i.e., engaging in diverse behaviors according to a hierarchy of risk by type of sex and partner serostatus) are phenomena widely described for men who have sex with men (MSM) in the developed world. We assessed seroadaptive behaviors among MSM surveyed in Yangon, Myanmar in 2013-2014. Among HIV-negative MSM, 43.1 % engaged in some form seroadaptation including serosorting (21.8 %), using condoms with potentially serodiscordant anal sex (19.3 %), and seropositioning (1.7 %). Among HIV-positive MSM, 3.5 % engaged in serosorting, 36.0 % in using condoms with potentially serodiscordant anal sex, 7.0 % in seropositioning, and 46.5 % in any form of seroadaptation. For HIV-negative and HIV-positive MSM, seroadaptation was more common than consistent condom use (38.0 and 26.7 %, respectively). MSM in Myanmar are engaging in seroadaptive behaviors in magnitude and ways similar to MSM in industrialized countries.

Wide-range frequency selectivity in an acoustic sensor fabricated using a microbeam array with non-uniform thickness

International Nuclear Information System (INIS)

Shintaku, Hirofumi; Kotera, Hidetoshi; Kobayashi, Takayuki; Zusho, Kazuki; Kawano, Satoyuki

2013-01-01

In this study, we have demonstrated the fabrication of a microbeam array (MBA) with various thicknesses and investigated the suitability it for an acoustic sensor with wide-range frequency selectivity. For this, an MBA composed of 64 beams, with thicknesses varying from 2.99–142 µm, was fabricated by using single gray-scale lithography and a thick negative photoresist. The vibration of the beams in air was measured using a laser Doppler vibrometer; the resonant frequencies of the beams were measured to be from 11.5 to 290 kHz. Lastly, the frequency range of the MBA with non-uniform thickness was 10.9 times that of the MBA with uniform thickness. (paper)

Projected space-time and varying speed of light

International Nuclear Information System (INIS)

Iovane, G.; Bellucci, S.; Benedetto, E.

2008-01-01

In this paper starting from El Naschie's Cantorian space-time and our model of projected Universe, we consider its properties in connection with varying speed of light. A possible way-out of the related problem is provided by the Fantappie group approach

Varying the exchange interaction between NiO nanoparticles

DEFF Research Database (Denmark)

Bahl, Christian Robert Haffenden; Mørup, Steen

2006-01-01

We demonstrate that exchange interactions between antiferromagnetic nanoparticles of 57Fe-doped NiO can be varied by simple macroscopic treatments. Mössbauer spectroscopy studies of the superparamagnetic relaxation behaviour show that grinding or suspension in water of nanoparticles of NiO can...