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Transmission
Kinds of Transmission Terms modified by Transmission Selected AbstractsNO EVIDENCE FOR PATIENT-TO-PATIENT TRANSMISSION OF HEPATITIS C VIRUS DURING UPPER GASTROINTESTINAL ENDOSCOPY: MOLECULAR STUDIES ON THREE ACUTE HEPATITIS C PATIENTSDIGESTIVE ENDOSCOPY, Issue 3 2009Takayuki Toda Background:, The risk of patient-to-patient transmission of hepatitis C virus (HCV) during endoscopy remains controversial. Using molecular approaches, we examined the possibility of patient-to-patient transmission of HCV in three patients who developed acute hepatitis C 1,6 months after examination by upper gastrointestinal endoscopy (UGIE) in a hospital endoscopy unit in Japan. Methods:, For the source of HCV infection, we used frozen sera obtained from potential candidates who underwent UGIE earlier than three index patients on the same days in the same unit. HCV genotype was determined by multiplex polymerase chain reaction (PCR) with genotype-specific primers. The 1087-nucleotide (nt) sequence of the NS5B region of the HCV genome was compared between index patients and their HCV-viremic candidates. Results:, The three index patients were exclusively infected with HCV of genotype 1b. Among a total of 60 candidate patients who underwent UGIE earlier than the index patients, 14 were positive for anti-HCV, of whom 12 had detectable HCV-RNA (1b, n = 9; 2a, n = 1; 2b, n = 2) on sera collected during each UGIE. Shared identity within the 1087-nt NS5B sequence was less than 95.0% between index patients and HCV/1b-infected candidates (n = 3, 1 and 5, respectively). None of the remaining 46 candidates who were negative for anti-HCV at UGIE examination tested positive for HCV-RNA, nor seroconverted to anti-HCV on their sera, which most likely excludes the possibility of HCV viremia despite the anti-HCV-negative serology at UGIE examination. Conclusion:, The present study suggests that patient-to-patient transmission of HCV during UGIE is infrequent. [source] HOST GROWTH CONDITIONS INFLUENCE EXPERIMENTAL EVOLUTION OF LIFE HISTORY AND VIRULENCE OF A PARASITE WITH VERTICAL AND HORIZONTAL TRANSMISSIONEVOLUTION, Issue 7 2010Hélène Magalon In parasites with mixed modes of transmission, ecological conditions may determine the relative importance of vertical and horizontal transmission for parasite fitness. This may lead to differential selection pressure on the efficiency of the two modes of transmission and on parasite virulence. In populations with high birth rates, increased opportunities for vertical transmission may select for higher vertical transmissibility and possibly lower virulence. We tested this idea in experimental populations of the protozoan Paramecium caudatum and its bacterial parasite Holospora undulata. Serial dilution produced constant host population growth and frequent vertical transmission. Consistent with predictions, evolved parasites from this "high-growth" treatment had higher fidelity of vertical transmission and lower virulence than parasites from host populations constantly kept near their carrying capacity ("low-growth treatment"). High-growth parasites also produced fewer, but more infectious horizontal transmission stages, suggesting the compensation of trade-offs between vertical and horizontal transmission components in this treatment. These results illustrate how environmentally driven changes in host demography can promote evolutionary divergence of parasite life history and transmission strategies. [source] ECONOMETRIC MODELS OF ASYMMETRIC PRICE TRANSMISSIONJOURNAL OF ECONOMIC SURVEYS, Issue 2 2007Giliola Frey Abstract In this paper, we review the existing empirical literature on price asymmetries in commodities, providing a way to classify and compare different studies that are highly heterogeneous in terms of econometric models, type of asymmetries and empirical findings. Relative to the previous literature, this paper is novel in several respects. First, it presents a detailed and updated survey of the existing empirical contributions on price asymmetries in the transmission mechanism linking input prices to output prices. Second, this paper presents an extension of the traditional distinction between long-run and short-run asymmetries to new categories of asymmetries, such as: contemporaneous impact, distributed lag effect, cumulated impact, reaction time, equilibrium and momentum equilibrium adjustment path, regime effect, regime equilibrium adjustment path. Each empirical study is then critically discussed in the light of this new classification of asymmetries. Third, this paper evaluates the relative merits of the most popular econometric models for price asymmetries, namely autoregressive distributed lags, partial adjustments, error correction models, regime switching and vector autoregressive models. Finally, we use the meta-regression analysis to investigate whether the results of asymmetry tests are not model-invariant and find which additional factors systematically influence the rejection of the null hypothesis of symmetric price adjustment. The main results of our survey can be summarized as follows: (i) each econometric model is specialized to capture a subset of asymmetries; (ii) each asymmetry is better investigated by a subset of econometric models; (iii) the general significance of the F test for asymmetric price transmission depends mainly on characteristics of the data, dynamic specification of the econometric model, and market characteristics. Overall, our empirical findings confirm that asymmetry, in all its forms, is very likely to occur in a wide range of markets and econometric models. [source] FINANCIAL CRISES AND INTERNATIONAL STOCK MARKET VOLATILITY TRANSMISSIONAUSTRALIAN ECONOMIC PAPERS, Issue 3 2010INDIKA KARUNANAYAKE This paper examines the interplay between stock market returns and their volatility, focusing on the Asian and global financial crises of 1997,98 and 2008,09 for Australia, Singapore, the UK, and the US. We use a multivariate generalised autoregressive conditional heteroskedasticity (MGARCH) model and weekly data (January 1992,June 2009). Based on the results obtained from the mean return equations, we could not find any significant impact on returns arising from the Asian crisis and more recent global financial crises across these four markets. However, both crises significantly increased the stock return volatilities across all of the four markets. Not surprisingly, it is also found that the US stock market is the most crucial market impacting on the volatilities of smaller economies such as Australia. Our results provide evidence of own and cross ARCH and GARCH effects among all four markets, suggesting the existence of significant volatility and cross volatility spillovers across all four markets. A high degree of time-varying co-volatility among these markets indicates that investors will be highly unlikely to benefit from diversifying their financial portfolio by acquiring stocks within these four countries only. [source] Transmission of human immune deficiency virus type-1 from mother to infantACTA PAEDIATRICA, Issue 11 2000R Zetterström No abstract is available for this article. [source] Gastrointestinal Bacterial Transmission among Humans, Mountain Gorillas, and Livestock in Bwindi Impenetrable National Park, UgandaCONSERVATION BIOLOGY, Issue 6 2008INNOCENT B. RWEGO ecología de enfermedades; Escherichia coli; primates; salud del ecosistema; zoonosis Abstract:,Habitat overlap can increase the risks of anthroponotic and zoonotic pathogen transmission between humans, livestock, and wild apes. We collected Escherichia coli bacteria from humans, livestock, and mountain gorillas (Gorilla gorilla beringei) in Bwindi Impenetrable National Park, Uganda, from May to August 2005 to examine whether habitat overlap influences rates and patterns of pathogen transmission between humans and apes and whether livestock might facilitate transmission. We genotyped 496 E. coli isolates with repetitive extragenic palindromic polymerase chain reaction fingerprinting and measured susceptibility to 11 antibiotics with the disc-diffusion method. We conducted population genetic analyses to examine genetic differences among populations of bacteria from different hosts and locations. Gorilla populations that overlapped in their use of habitat at high rates with people and livestock harbored E. coli that were genetically similar to E. coli from those people and livestock, whereas E. coli from gorillas that did not overlap in their use of habitats with people and livestock were more distantly related to human or livestock bacteria. Thirty-five percent of isolates from humans, 27% of isolates from livestock, and 17% of isolates from gorillas were clinically resistant to at least one antibiotic used by local people, and the proportion of individual gorillas harboring resistant isolates declined across populations in proportion to decreasing degrees of habitat overlap with humans. These patterns of genetic similarity and antibiotic resistance among E. coli from populations of apes, humans, and livestock indicate that habitat overlap between species affects the dynamics of gastrointestinal bacterial transmission, perhaps through domestic animal intermediates and the physical environment. Limiting such transmission would benefit human and domestic animal health and ape conservation. Resumen:,El traslape de hábitats puede incrementar los riesgos de transmisión de patógenos antroponótica y zoonótica entre humanos, ganado y simios silvestres. Recolectamos bacterias Escherichia coli de humanos, ganado y gorilas de montaña (Gorilla gorilla beringei) en el Parque Nacional Bwindi Impenetrable, Uganda, de mayo a agosto 2005 para examinar sí el traslape de hábitat influye en las tasas y patrones de transmisión de patógenos entre humanos y simios y sí el ganado facilita esa transmisión. Determinamos el genotipo de 496 aislados de E. coli con marcaje de reacción en cadena de polimerasa palindrómica extragénica (rep-PCR) y medimos la susceptibilidad a 11 antibióticos con el método de difusión de disco. Realizamos análisis de genética poblacional para examinar las diferencias genéticas entre poblaciones de bacterias de huéspedes y localidades diferentes. Las poblaciones de gorilas con alto grado de traslape en el uso de hábitat con humanos y ganado presentaron E. coli genéticamente similar a E. coli de humanos y ganado, mientras que E. coli de gorilas sin traslape en el uso hábitat con humanos y ganado tuvo relación lejana con las bacterias de humanos y ganado. Treinta y cinco porciento de los aislados de humanos, 27% de los aislados de ganado y 17% de los aislados de gorilas fueron clínicamente resistentes a por lo menos un antibiótico utilizado por habitantes locales, y la proporción de gorilas individuales con presencia de aislados resistentes declinó en las poblaciones proporcionalmente con la disminución en el grado de traslape con humanos. Estos de patrones de similitud genética y resistencia a antibióticos entre E. coli de poblaciones de simios, humanos y ganado indican que el traslape de hábitat entre especies afecta la dinámica de transmisión de bacterias gastrointestinales, probablemente a través de animales domésticos intermediarios y el ambiente físico. La limitación de esa transmisión beneficiaría a la salud de humanos y animales domésticos y a la conservación de simios. [source] Improvements in the 2D TEP Neutral Particle Transport Calculation in Edge PlasmasCONTRIBUTIONS TO PLASMA PHYSICS, Issue 7-9 2006D. Zhang Abstract Extensions of the 2D Transmission and Escape Probability neutral particle transport method in treating the spatial non-uniformity of collision sources and neutral energy effects are presented. These extensions have been tested by benchmarks against Monte Carlo calculations for specially designed models and for realistic DIII-D discharges. The comparisons indicate these extensions improve accuracy of the TEP method. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Family factors in the intergenerational transmission of offendingCRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 2 2009David P. Farrington Background,Convicted parents tend to have convicted children, but there have been few previous studies of transmission between three generations, especially including both records and interviews for hundreds of people. Method,In the Cambridge Study in Delinquent Development (CSDD), 411 south London males have been followed up from age 8 to age 48. These males (generation 2, G2) are compared with their fathers and mothers (generation 1, G1), and with their biological sons and daughters (generation 3, G3). Results,There was significant intergenerational transmission of convictions from G1 males to G2 males, and from G2 males to G3 males. Convictions of fathers still predicted convictions of sons after controlling for risk factors, but the predictive efficiency was reduced. Transmission was less from G1 females to G2 males, and from G2 males to G3 females. There was little evidence of intergenerational transmission from G1 to G3, except from grandmothers to granddaughters. Conclusions,The intergenerational transmission of offending may be mediated by family, socio-economic and individual risk factors. Intervention to reduce intergenerational transmission could target these risk factors. Copyright © 2009 John Wiley & Sons, Ltd. [source] Costs of cannibalism in the presence of an iridovirus pathogen of Spodoptera frugiperdaECOLOGICAL ENTOMOLOGY, Issue 2 2006Trevor Williams Abstract., 1.,The costs of cannibalism were examined in larvae of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) in the presence of conspecifics infected by a lethal invertebrate iridescent virus (IIV). The hypothesis of a positive correlation between insect density and the likelihood of disease transmission by cannibalism was examined in laboratory microcosms and a field experiment. 2.,Transmission was negligible following peroral infection of early instars with purified virus suspensions or following coprophagy of virus-contaminated faeces excreted by infected insects. In contrast, 92% of the insects that predated infected conspecifics acquired the infection and died prior to adult emergence in the laboratory. Diseased larvae were more likely to be victims of cannibalism than healthy larvae. 3.,The prevalence of cannibalism was density dependent in laboratory microcosms with a low density (10 healthy insects + one infected insect) or high density (30 healthy insects + one infected insect) of insects, and field experiments performed on maize plants infested with one or four healthy insects + one infected insect. 4.,Cannibalism in the presence of virus-infected conspecifics was highly costly to S. frugiperda; in all cases, insect survival was reduced by between ,,50% (laboratory) and ,,30% (field) in the presence of the pathogen. Contrary to expectations, the prevalence of disease was not sensitive to density because cannibalism resulted in self-thinning. As infected individuals are consumed and disappear from the population, the prevalence of disease will be determined by the timescale over which transmission can be achieved, and the rate at which individuals that have acquired an infection become themselves infectious to conspecific predators. [source] Tospoviruses infecting vegetable crops in IsraelEPPO BULLETIN, Issue 2 2000A. Gera Symptoms of vein clearing, stem necrosis, curling, necrotic spots and rings on the leaves associated with infection by tomato spotted wilt tospovirus (TSWV) were documented among vegetable crops growing in commercial glasshouses and open fields in Israel. Plants exhibiting symptoms were collected, from 1994-01 to 1998-12. Among cultivated vegetable crops analysed for TSWV by ELISA, the following plants were found to be infected: tomato, capsicum, aubergine, lettuce, cabbage and cucumber. These incidences of the virus were all correlated with the occurrence in high population of Frankliniella occidentalis. Transmission of the virus from infected Datura stramonium to Petunia leaf discs, by F. occidentalis, was up to 26%. TSWV antigens were readily detected by ELISA in seeds harvested from naturally infected vegetable crops. However, we failed to show virus transmission to the progeny plants. Iris yellow spot tospovirus (IYSV) was detected in onion. High incidence of the disease was associated with large populations of Thrips tabaci. [source] Transmission of Ehrlichia risticii, the agent of Potomac horse fever, using naturally infected aquatic insects and helminth vectors: preliminary reportEQUINE VETERINARY JOURNAL, Issue 4 2000J. E. Madigan Summary Ehrlichia risticii, the agent of Potomac horse fever (PHF), has been recently detected in trematode stages found in snail secretions and in aquatic insects. Based on these findings, horses could conceivably be exposed to E. risticii by skin penetration with infected cercariae, by ingestion of infected cercariae in water or via metacercariae in a second intermediate host, such as an aquatic insect. In order to test this hypothesis, horses were challenged with infectious snail secretions and aquatic insects collected from a PHFendemic region in northern California. Two horses stood with their front feet in waterharbouring E. risticii -infected cercariae, 2 horses drank water harbouring E. risticii -infected cercariae, and 6 horses were fed pools of different aquatic insects harbouring E. risticii -infected metacercariae. In this preliminary study, only the one horse infected orally with mature caddisflies (Dicosmoecus gilvipes) developed the clinical and haematological disease syndrome of PHF. The agent was isolated from the blood of the infected horse in a continuous cell line and identified as E. risticii by characterisation of the 16S rRNA gene. Therefore, E. risticii is maintained in nature in a complex aquatic ecosystem and transmission to horses can occur through accidental ingestion of insects such as caddisflies containing infected metacercariae. At present, the small number of horses used in this study does not exclude other insects and free trematode stages as potential sources of infection. [source] First Documentation of Cultural Transmission of Predator Recognition by Larval AmphibiansETHOLOGY, Issue 6 2007Maud C. O. Ferrari Predation is a pervasive selective agent shaping a prey's behaviour, morphology and life history. To survive, prey animals have to respond adaptively to predation threats and this can be achieved through learned predator recognition. Cultural transmission of predator recognition is likely a widespread means of learning in social animals, including mammals, birds and fishes. However, no studies have investigated the cultural transmission of predator recognition in amphibians. In our study, we examined whether naïve woodfrog (Rana sylvatica) tadpoles can acquire the recognition of the odour of a predatory tiger salamander (Ambystoma tigrinum) from experienced conspecifics. After conditioning some tutors to recognize salamander odour, we paired naïve observer tadpoles with either a salamander-naïve or salamander-experienced tutor and exposed the pairs to either salamander odour or a water control. Observers were subsequently tested alone for a response to salamander odour. We found that when given salamander odour, observer tadpoles that were paired with a salamander-experienced tutor successfully learned to recognize the salamander odour as a threat, whereas the observers paired with salamander-naïve tutors did not. Likewise, tadpoles exposed to the water control did not learn to recognize the salamander regardless of whether they were paired with a naïve or experienced tutor. This is the first study demonstrating cultural transmission of predator recognition in an amphibian species. [source] Letter: Compressed Disparity Information Transmission over Constant Bit Rate ATM ChannelsEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 5 2000Dionysis Papadimatos This letter presents a real-time lossless compression/decompression unit for disparity map information used in 3D teleconferencing systems. A lossless compression algorithm is used to compress the disparity map data in real-time, resulting in a variable bit-rate data stream that has to be transmitted through a constant bit-rate channel. The system uses a controlled-data-loss method for data rate adaptation and for minimizing the loss of information. [source] Price and Volatility Transmission across BordersFINANCIAL MARKETS, INSTITUTIONS & INSTRUMENTS, Issue 3 2006Louis Gagnon Over the past forty years, financial markets throughout the world have steadily become more open to foreign investors. With open markets, asset prices are determined globally. A vast literature on portfolio choice and asset pricing has evolved to study the importance of global factors as well as local factors as determinants of portfolio choice and of expected returns on risky assets. There is growing evidence that risk premia are increasingly determined globally. An important outcome of this force of globalization is increased comovement in asset prices across markets. This survey study examines the literature on the dynamics of comovements in asset prices and volatility across markets around the world. The literature began in the 1970s in conjunction with early theoretical developments on international asset pricing models, but it blossomed in the late 1980s and early 1990s with the availability of comprehensive international stock market databases and the development of econometric methodology to model these dynamics. [source] Solar Energy Collectors with Tunable TransmissionADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Michael G. Debije Abstract A new type of "smart" window is proposed that makes use of fluorescent dye guests in a liquid-crystal host sandwiched between glass panels. The dye absorbs a variable amount of light depending on its orientation, and re-emits this light, of which a significant fraction is trapped by total internal reflection at the glass,air interface, and becomes concentrated along the edges. Such a device could both generate electricity via an attached photovoltaic as well as allow user control of the amount of transmitted light. By applying a voltage across the cell, absorption could be varied 31%, while the usable light output only varied 11% due to the increased efficiency of light collection at homeotropic dye orientation. [source] Multivariate GARCH Modeling of Exchange Rate Volatility Transmission in the European Monetary SystemFINANCIAL REVIEW, Issue 1 2000Colm Kearney C32/F31/G15 Abstract We construct a series of 3-, 4- and 5-variable multivariate GARCH models of exchange rate volatility transmission across the important European Monetary System (EMS) currencies including the French franc, the German mark, the Italian lira, and the European Currency Unit. The models are estimated without imposing the common restriction of constant correlation on both daily and weekly data from April 1979,March 1997. Our results indicate the importance of checking for specification robustness in multivariate Generalized Autoregressive Conditional Heleroskedasticity (GARCH) modeling, we find that increased temporal aggregation reduces observed volatility transmission, and that the mark plays a dominant position in terms of volatility transmission. [source] Firm Size, Industry Mix and the Regional Transmission of Monetary Policy in GermanyGERMAN ECONOMIC REVIEW, Issue 1 2004Ivo J. M. Arnold Monetary transmission; regional effects; industry effects; firm size Abstract. This paper estimates the impact of interest rate shocks on regional output in Germany over the period from 1970 to 2000. We use a vector autoregression (VAR) model to obtain impulse responses, which reveal differences in the output responses to monetary policy shocks across ten German provinces. Next, we investigate whether these differences can be related to structural features of the regional economies, such as industry mix, firm size, bank size and openness. An additional analysis of the volatility of real GDP growth for the period 1992,2000 includes the Eastern provinces. We also present evidence on the interrelationship between firm size and industry, and compare our measure of firm size with those used in previous studies. We conclude that the differential regional effects of monetary policy are related to industrial composition, but not to firm size or bank size. [source] Synaptic Transmission: Inhibition of Neurotransmitter Release by Botulinum ToxinsHEADACHE, Issue 2003Oliver Dolly MSc Botulinum toxin type A, a protein long used in the successful treatment of various dystonias, has a complex mechanism of action that results in muscle relaxation. At the neuromuscular junction, the presynaptic nerve ending is packed with synaptic vesicles filled with acetylcholine, and clustered at the tip of the folds of the postsynaptic muscle membrane are the acetylcholine receptors. Synaptic vesicles fuse with the membrane in response to an elevation of intraneuronal calcium concentration and undergo release of their transmitter by exocytosis. Intracellular proteins that contribute to the fusion of the vesicles with the plasma membrane during exocytosis include synaptosomal protein with a molecular weight of 25 kDa (SNAP-25); vesicle-associated membrane protein (VAMP), also known as synaptobrevin; and syntaxin. Through their proteolytic action on these proteins, botulinum toxins prevent exocytosis, thereby inhibiting the release of acetylcholine. There are 7 serotypes of this toxin,A, B, C1, D, E, F, and G,and each cleaves a different intracellular protein or the same target at distinct bonds. The separate cleavage sites in SNAP-25 for botulinum toxin types A and E contribute to their dissimilar durations of muscle relaxation. This report describes the molecular basis for the inhibition by botulinum toxins of neuroexocytosis and subsequent functional recovery at the neuromuscular junction. [source] Dynamic Assessment of Abnormalities in Central Pain Transmission and Modulation in Tension-type Headache SufferersHEADACHE, Issue 2 2000Jonathan D. Neufeld PhD Objective.,To examine and compare central pain processing and modulation in young tension-type headache sufferers with that of matched healthy controls using an induced headache "challenge" paradigm. Background.,Recent research has suggested that abnormalities in central pain processing and descending pain modulation may contribute to chronic tension-type headache. These abnormalities, if they contribute to headache pathogenesis, should be present in young adult tension-type headache sufferers. Recent research using static measures of physiological variables, such as muscle tenderness and exteroceptive suppression, has identified chronic muscle tenderness as a characteristic of young tension-type headache sufferers, but other central nervous system functional abnormalities may require a dynamic "challenge" to be observed. Methods.,Twenty-four young women meeting the International Headache Society diagnostic criteria for tension-type headache (headache-prone) and a matched group of 24 healthy women who reported fewer than 10 problem headaches per year (control) participated in a double-blind, placebo-controlled, crossover study. Subjects completed jaw clenching and a placebo condition on different days in counterbalanced order. Pericranial muscle tenderness, pressure-pain thresholds on the temporalis, and exteroceptive suppression periods were assessed before and after each procedure. Head pain was recorded for 12 to16 hours following each condition. Results.,Headache-prone subjects were more likely than controls to experience headaches after both the jaw clenching and placebo procedures, but neither group was significantly more likely to experience headaches following jaw clenching than placebo. In pretreatment measurements, headache-prone subjects exhibited greater muscle tenderness than controls, but pressure-pain detection thresholds and exteroceptive suppression periods did not differ in the two groups. Control subjects showed increases in muscle tenderness and exteroceptive suppression periods following both the clenching and placebo procedures, whereas headache-prone subjects exhibited no significant changes in any of the physiological measures following either experimental manipulation. Conclusions.,These results confirm previous findings indicating abnormally high pericranial muscle tenderness in young tension headache sufferers even in the headache-free state. In addition, the results suggest that the development of headaches following noxious stimulation is more strongly related to headache proneness and associated abnormalities in central pain transmission or modulation (indexed by pericranial muscle tenderness and exteroceptive suppression responses) than muscle strain induced by jaw clenching. [source] P03 Epidemiology and TransmissionHELICOBACTER, Issue 4 2009Article first published online: 23 JUL 200 First page of article [source] Intrafamilial Transmission of Helicobacter pylori among the Population of Endemic Areas in JapanHELICOBACTER, Issue 2 2007Yayoi Fujimoto Abstract Background:,Helicobacter pylori (H. pylori) infection is a worldwide phenomenon related to several gastrointestinal diseases. However, because many aspects concerning the route of transmission remain unclear, we performed this epidemiologic study to clarify the route of intrafamilial transmission of H. pylori. Materials and Methods:, A retrospective study was performed in three widely separate areas in Japan to investigate the prevalence of H. pylori infection. In 1993, 613 residents were tested as were 4136 in 2002, including 1447 family members of 625 families. Antibody to H. pylori (anti- H. pylori) was determined by enzyme-linked immunosorbent assay. Results:, In 2002, the age-adjusted anti- H. pylori prevalence in Hoshino Village (67.5%) was significantly higher than in Kasuya Town (55.0%) and in Ishigaki City (54.7%) (p < .0001, p = .0039, respectively). The age-adjusted anti- H. pylori prevalence of Ishigaki City significantly decreased from 1993 (68.4%) to 2002 (52.5%), showing an age cohort effect. However, the prevalence did not significantly differ in children aged 0,6 years of Ishigaki City between 1993 (9.6%) and 2002 (10.3%). A familial analysis in 2002 demonstrated that the prevalence of anti- H. pylori was significantly higher in children with anti- H. pylori -positive (21.6%, 22 of 102) than with -negative mothers (3.2%, 3 of 95) (p < .0001, by Mantel,Haenszel test), whereas there was no significant difference between children with anti- H. pylori -positive and -negative fathers. Moreover, the prevalence was significantly higher in wives with anti- H. pylori -positive (64.0%, 208 of 325) than with -negative husbands (46.5%, 80 of 172) (p = .0071, by Mantel,Haenszel test) and in husbands with anti- H. pylori -positive (72.2%, 208 of 288) than with -negative wives (56.0%, 117 of 209) (p = .0106, by Mantel,Haenszel test). Conclusions:, In the last decade, H. pylori infection decreased in the general population of Japan by improvement of general hygiene conditions, but did not differ in young children, most likely because of mother-to-child transmission. [source] Epidemiology of Helicobacter pylori infectionHELICOBACTER, Issue 2003Hoda M. Malaty ABSTRACT Transmission of the infection revealed in many articles an important role of the mothers in transmitting the infection to their children. The epidemiology and risk factors of Helicobacter pylori infection were examined. The seroprevalence of the infection in different populations as well as colonization of the infection in childhood was reported. Moreover, this year attention was aimed at examining the associations between Helicobacter pylori with gastrointestinal and nongastrointestinal diseases. [source] Maternal-infant transmission of hepatitis C virus infectionHEPATOLOGY, Issue 5B 2002Eve A. Roberts 555 University Ave. Mother-to-infant transmission of hepatitis C virus (HCV) is comparatively uncommon. The prevalence of antibody to HCV (anti-HCV) in pregnant women is 0.1% to 2.4%, although in some endemic areas it is much higher. The proportion of women with anti-HCV who have active infection with viremia is 60% to 70%. Transmission of HCV occurs only when serum HCV RNA is detectable and may be related to higher levels (above 106 copies per mL). The rate of mother-to-infant transmission is 4% to 7% per pregnancy in women with HCV viremia. Co-infection with human immunodeficiency virus (HIV) increases the rate of transmission 4 to 5 fold. The actual time and mode of transmission are not known. Elective Cesarean section is not recommended for women with chronic HCV infection alone. The role of treatment to prevent transmission is limited by the fetal toxicity of currently available medications for hepatitis C. Breast feeding poses no important risk of HCV transmission if nipples are not traumatized and maternal hepatitis C is quiescent. Pregnant women at high risk for HCV infection should be screened for anti-HCV, and HCV RNA testing should be performed if anti-HCV is positive. Infants of women with hepatitis C should be tested for HCV RNA on two occasions, between the ages of 2 and 6 months and again at 18 to 24 months, along with serum anti-HCV. The natural history of mother-to-infant hepatitis C remains uncertain, especially the course in the first year of life when some infants appear to have spontaneous resolution. [source] Maternal-infant transmission of hepatitis C virus infectionHEPATOLOGY, Issue S1 2002Eve A. Roberts M.D., FRCPC Mother-to-infant transmission of hepatitis C virus (HCV) is comparatively uncommon. The prevalence of antibody to HCV (anti-HCV) in pregnant women is 0.1% to 2.4%, although in some endemic areas it is much higher. The proportion of women with anti-HCV who have active infection with viremia is 60% to 70%. Transmission of HCV occurs only when serum HCV RNA is detectable and may be related to higher levels (above 106 copies per mL). The rate of mother-to-infant transmission is 4% to 7% per pregnancy in women with HCV viremia. Co-infection with human immunodeficiency virus (HIV) increases the rate of transmission 4 to 5 fold. The actual time and mode of transmission are not known. Elective Cesarean section is not recommended for women with chronic HCV infection alone. The role of treatment to prevent transmission is limited by the fetal toxicity of currently available medications for hepatitis C. Breast feeding poses no important risk of HCV transmission if nipples are not traumatized and maternal hepatitis C is quiescent. Pregnant women at high risk for HCV infection should be screened for anti-HCV, and HCV RNA testing should be performed if anti-HCV is positive. Infants of women with hepatitis C should be tested for HCV RNA on two occasions, between the ages of 2 and 6 months and again at 18 to 24 months, along with serum anti-HCV. The natural history of mother-to-infant hepatitis C remains uncertain, especially the course in the first year of life when some infants appear to have spontaneous resolution. (HEPATOLOGY 2002;36:S106,S113). [source] Seroprevalence of HIV infection in hospitalized paediatric patients at a tertiary care centre in western IndiaHIV MEDICINE, Issue 4 2007I Shah The prevalence of HIV infection in children in India is not known. In this study, a total of 270 children admitted to paediatric wards in Mumbai were screened for HIV infection by enzyme-linked immunosorbent assay (ELISA). Eight patients (2.96%) had a positive HIV ELISA. Of these two patients (25%) were less than 15 months of old and hence HIV infection in them could not be confirmed. The prevalence of HIV was 2.3%. Three out of 11 patients with tuberculosis (27.3%) and four out of 15 patients with nutritional anaemia (26.7%) had HIV infection (P<0.0001 in each case). Vertical transmission was the cause in all children, suggesting that implementation of Prevention of Parent to Child Transmission of HIV (PPTCT) is required to reduce the rate of paediatric HIV infection. [source] Imagining the Future: Children, Education and Intergenerational Transmission of Poverty in Urban BangladeshIDS BULLETIN, Issue 1 2009Naila Kabeer Failure to invest in children's education is widely recognised as a key mechanism for the intergenerational transmission of poverty. At the same time, rising levels of education among different socioeconomic groups in countries like Bangladesh suggest that poverty on its own is not an adequate explanation for this failure. This article uses survey data on low-income households in urban Bangladesh to explore what differentiates parents who have managed to send their children to school from those who have not. One factor is education: parents with no education are more likely to have children of school-going age who are not at school. Different aspects of household vulnerability, as captured by asset deficits, reliance on casual labour and female headship, also play an important role in determining whether children go to school or not. In addition, the article argues that contextual factors have an important influence on how parents imagine their children's future and how children themselves regard education. The hazards of daily life in slum environments, the limited range of job opportunities available and the absence of decent educational facilities all serve to undermine parental commitment and children's motivation with regard to education. The article suggests that the state and civil society should collaborate to promote educational and livelihood interventions which are responsive to the needs of the more vulnerable sections of the poor and to reshape how parents and children envisage the future. [source] Gradualism, Transparency and the Improved Operational Framework: A Look at Overnight Volatility Transmission,INTERNATIONAL FINANCE, Issue 2 2009Silvio Colarossi This paper proposes a possible way of assessing the effect on interest rate dynamics of changes in the decision-making method, in the communication strategy and in the operational framework of a central bank. Through a generalized autoregressive conditional heteroscedasticity (GARCH) specification, we show that the United States and the euro area displayed a limited but significant spillover of volatility from money market to longer-term rates. We then checked the stability of this phenomenon in the most recent period of improved policy-making and found empirical evidence to show that the transmission of overnight volatility along the yield curve had entirely disappeared. [source] An investigation of solar erythemal ultraviolet radiation in the tropics: a case study at four stations in ThailandINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 12 2010Serm Janjai Abstract Our study examines a 5-year data set of erythemal ultraviolet radiation (EUV) collected at four locations in Thailand: Chiang Mai (18.78°N, 98.98°E), Ubon Ratchathani (15.25°N, 104.87°E), Nakhon Pathom (13.82°N, 100.04°E) and Songkhla (7.20°N, 100.60°E). Seasonal changes are strongly influenced by the wet and dry season in this tropical environment, with maximum daily and noontime irradiances being reached in April or May, prior to the onset of the wet season. Transmission by aerosols, estimated by comparison of cloudless measured irradiance with a cloudless sky model, ranges from 51% at Chiang Mai to 83% at Songkhla during the dry season. By contrast, higher transmissions characterise the wet season when values around 90% are reached. Cloud cover further depletes the EUV irradiance and wet season transmissions range from 68% at Chiang Mai to 79% at Songkhla. Three of the four stations record increases in EUV irradiance over the study period. Copyright © 2009 Royal Meteorological Society [source] Transmission on indoor power lines: from a stochastic channel model to the optimization and performance evaluation of multicarrier systemsINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2003Virginie Degardin Abstract This paper deals with optimization and performance evaluation of multicarrier transmissions on indoor power lines, taking the actual channel characteristics into account. From intensive measurements of noise on lines, the most significant parameters of impulsive noise were defined and classified, and then a statistical study was carried out. The other types of noise, i.e. narrow band and coloured noise have also been characterized. In like manner, the transfer functions between two points of a power line network have been measured. From all these data, a stochastic channel model representative of the environment is built and implemented in a software tool simulating the link. Various transmission schemes have been considered to mitigate the effects on one hand of the stationary noise, the channel frequency selectivity and of the change of its state, and on the other, on the impulsive noise. These techniques are optimized for the indoor power line environment and their performances, expressed in terms of bit error rate, are compared. Copyright © 2003 John Wiley & Sons, Ltd. [source] Oral health care for pregnant and postpartum womenINTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 3 2003M. Perno Goldie Abstract Pregnancy may pose a number of concerns to the mother and the foetus. This can include systemic and oral issues that effect health. Transmission of caries-causing bacteria is one problem that can be minimized by utilizing simple, cost-effective measures. Chlorhexidine rinses and xylitol containing chewing gum will be discussed as possible solutions to this tremendous public health problem. [source] | ||||||||||||||||||||||||||||||||||||||||||||||