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2.
Prev Vet Med ; 189: 105282, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33556799

RESUMEN

Q fever is a zoonotic disease caused by infection with Coxiella burnetii transmitted from animals including, but not limited to, cattle, sheep and goats. The infection in cattle is typically sub-clinical with some evidence suggesting associated reproductive loss. There is currently limited data on the true prevalence and distribution of coxiellosis in beef cattle across northern Australia. During this study, 2,012 sera samples from beef cattle managed on commercial farms located in Queensland and the Northern Territory were tested using an indirect immunofluorescent assay (IFA) for serological evidence of IgG antibodies against C. burnetii. Bayesian latent class models were used to estimate the true prevalence, adjusted for diagnostic test sensitivity and specificity and incorporating the hierarchical structure of the cattle within farms and regions. In this study, cattle in the Northern Territory had lower estimated true prevalence than cattle within most regions of Queensland with the exception of south-east Queensland. Results from this study have described the geographic distribution and estimated the true prevalence of antibodies to C. burnetii in a sample of extensively managed beef cattle located across the tropical grazing regions of northern Australia.


Asunto(s)
Enfermedades de los Bovinos , Coxiella burnetii , Fiebre Q , Animales , Anticuerpos Antibacterianos , Teorema de Bayes , Bovinos , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/epidemiología , Coxiella burnetii/inmunología , Pruebas Diagnósticas de Rutina/veterinaria , Ensayo de Inmunoadsorción Enzimática/veterinaria , Northern Territory , Prevalencia , Fiebre Q/diagnóstico , Fiebre Q/epidemiología , Fiebre Q/veterinaria , Queensland , Estudios Seroepidemiológicos , Incertidumbre
3.
Mol Biol Rep ; 47(1): 715-720, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31659694

RESUMEN

Human parechovirus (HPeV) is an emerging pathogen for infants. Improved diagnostics are needed due to the non-specific clinical presentation. Real-time reverse transcription polymerase chain reaction (RT-PCR) on blood samples may be an adjunct to diagnosis. A retrospective cohort of HPeV-affected infants was used to assess sensitivity and specificity of a HPeV RT-PCR on blood and cerebrospinal fluid (CSF). As a secondary analysis, the Ct value of the PCR results was compared to clinical correlates of severity. Between 2017 and 2018 blood samples were obtained from 97 infants of whom 44 had HPeV clinical and laboratory proven infection. Eighty-three concurrent CSF samples were available. Sensitivity was 93.3% [95% CI 82-99] for blood HPeV RT-PCR and 85% [95% CI 73.9-96.1] for CSF HPeV RT-PCR. Blood HPeV RT-PCR Ct values < 25 cycles were associated with age < 28 days and < 3 days of symptoms. No statistical associations were identified between potential clinical markers of severity and Ct value. HPeV RT-PCR on blood is a valuable adjunct to diagnostic testing for acute HPeV-related illness in infants. Results can be expected to be robust until at least day 5 of symptoms, with optimal sampling occurring close to onset of symptoms.


Asunto(s)
Tipificación Molecular/métodos , Parechovirus/genética , Infecciones por Picornaviridae/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , ARN Viral/sangre , Humanos , Lactante , Recién Nacido , Infecciones por Picornaviridae/virología , ARN Viral/líquido cefalorraquídeo , Sensibilidad y Especificidad
4.
Phys Rev Lett ; 121(11): 117201, 2018 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-30265101

RESUMEN

We report an extraordinary pressure dependence of the magnetic interactions in the metal-organic system [CuF_{2}(H_{2}O)_{2}]_{2}pyrazine. At zero pressure, this material realizes a quasi-two-dimensional spin-1/2 square-lattice Heisenberg antiferromagnet. By high-pressure, high-field susceptibility measurements we show that the dominant exchange parameter is reduced continuously by a factor of 2 on compression. Above 18 kbar, a phase transition occurs, inducing an orbital re-ordering that switches the dimensionality, transforming the quasi-two-dimensional lattice into weakly coupled chains. We explain the microscopic mechanisms for both phenomena by combining detailed x-ray and neutron diffraction studies with quantitative modeling using spin-polarized density functional theory.

5.
Regul Toxicol Pharmacol ; 88: 144-156, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28559157

RESUMEN

In order to accurately assess aggregate exposure to a fragrance material in consumers, data are needed on consumer habits and practices, as well as the concentration of the fragrance material in those products. The present study describes the development of Phase 2 Creme RIFM model by expanding the previously developed Phase 1 model to include an additional six product types. Using subject-matching algorithms, the subjects in the Phase 1 Creme RIFM database were paired with subjects in the SUPERB and BodyCare surveys based on age and gender. Consumption of the additional products was simulated to create a seven day diary allowing full data integration in a consistent format. The inhalation route was also included for air care and other products where a fraction of product used is inhaled, derived from the RIFM 2-box model. The expansion of the Phase 1 Creme RIFM model has resulted in a more extensive and refined model, which covers a broader range of product categories and now, includes all relevant routes of exposure. An evaluation of the performance of the model has been carried out in an accompanying publication to this one.


Asunto(s)
Algoritmos , Cosméticos , Hábitos , Adulto , Aerosoles , Seguridad de Productos para el Consumidor , Cosméticos/química , Femenino , Preparaciones para el Cabello/química , Humanos , Exposición por Inhalación , Masculino , Análisis por Apareamiento , Persona de Mediana Edad , Perfumes/química , Jabones/química
6.
Regul Toxicol Pharmacol ; 86: 148-156, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28257852

RESUMEN

As part of a joint project between the Research Institute for Fragrance Materials (RIFM) and Creme Global, a Monte Carlo model (here named the Creme RIFM model) has been developed to estimate consumer exposure to ingredients in personal care products. Details of the model produced in Phase 1 of the project have already been published. Further data on habits and practises have been collected which enable the model to estimate consumer exposure from dermal, oral and inhalation routes for 25 product types. . In addition, more accurate concentration data have been obtained which allow levels of fragrance ingredients in these product types to be modelled. Described is the use of this expanded model to estimate aggregate systemic exposure for eight fragrance ingredients. Results are shown for simulated systemic exposure (expressed as µg/kg bw/day) for each fragrance ingredient in each product type, along with simulated aggregate exposure. Highest fragrance exposure generally occurred from use of body lotions, body sprays and hydroalcoholic products. For the fragrances investigated, aggregate exposure calculated using this model was 11.5-25 fold lower than that calculated using deterministic methodology. The Creme RIFM model offers a very comprehensive and powerful tool for estimating aggregate exposure to fragrance ingredients.


Asunto(s)
Aire/análisis , Cosméticos/química , Administración Cutánea , Exposición a Riesgos Ambientales , Modelos Teóricos , Método de Montecarlo , Perfumes/química
8.
Sci Rep ; 6: 25335, 2016 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-27174799

RESUMEN

One early triumph of quantum physics is the explanation why some materials are metallic whereas others are insulating. While a treatment based on single electron states is correct for most materials this approach can fail spectacularly, when the electrostatic repulsion between electrons causes strong correlations. Not only can these favor new and subtle forms of matter, such as magnetism or superconductivity, they can even cause the electrons in a half-filled energy band to lock into position, producing a correlated, or Mott insulator. The transition into the Mott insulating state raises important fundamental questions. Foremost among these is the fate of the electronic Fermi surface and the associated charge carrier mass, as the Mott transition is approached. We report the first direct observation of the Fermi surface on the metallic side of a Mott insulating transition by high pressure quantum oscillatory measurements in NiS2. Our results point at a large Fermi surface consistent with Luttinger's theorem and a strongly enhanced quasiparticle effective mass. These two findings are in line with central tenets of the Brinkman-Rice picture of the correlated metal near the Mott insulating state and rule out alternative scenarios in which the carrier concentration vanishes continuously at the metal-insulator transition.

9.
Sci Rep ; 5: 13451, 2015 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-26307952

RESUMEN

We report magnetotransport investigation of nonmagnetic InSb single crystal doped with manganese at Mn concentration NMn ~ 1,5 × 10(17) cm(-3) in the temperature range T = 300 K-40 mK, magnetic field B = 0-25T and hydrostatic pressure P = 0-17 kbar. Resistivity saturation was observed in the absence of magnetic field at temperatures below 200 mK while applied increasing external magnetic field induced colossal drop of resistivity (by factor 10(4)) at B ~ 4T with further gigantic resistivity increase (by factor 10(4)) at 15T. Under pressure, P = 17 kbar, resistivity saturation temperature increased up to 1,2 K. Existing models are discussed in attempt to explain resistivity saturation, dramatic influence of magnetic field and pressure on resistivity with the focus on possible manifestation of three dimensional Wigner crystal formed in InSb by light electrons and heavy holes.

10.
Regul Toxicol Pharmacol ; 72(3): 673-82, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26071898

RESUMEN

Ensuring the toxicological safety of fragrance ingredients used in personal care and cosmetic products is essential in product development and design, as well as in the regulatory compliance of the products. This requires an accurate estimation of consumer exposure which, in turn, requires an understanding of consumer habits and use of products. Where ingredients are used in multiple product types, it is important to take account of aggregate exposure in consumers using these products. This publication investigates the use of a newly developed probabilistic model, the Creme RIFM model, to estimate aggregate exposure to fragrance ingredients using the example of 2-phenylethanol (PEA). The output shown demonstrates the utility of the model in determining systemic and dermal exposure to fragrances from individual products, and aggregate exposure. The model provides valuable information not only for risk assessment, but also for risk management. It should be noted that data on the concentrations of PEA in products used in this article were obtained from limited sources and not the standard, industry wide surveys typically employed by the fragrance industry and are thus presented here to illustrate the output and utility of the newly developed model. They should not be considered an accurate representation of actual exposure to PEA.


Asunto(s)
Cosméticos , Exposición a Riesgos Ambientales/análisis , Modelos Teóricos , Perfumes , Adulto , Seguridad de Productos para el Consumidor , Europa (Continente) , Humanos , Alcohol Feniletílico , Estados Unidos
11.
Regul Toxicol Pharmacol ; 72(3): 660-72, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26003515

RESUMEN

Exposure of fragrance ingredients in cosmetics and personal care products to the population can be determined by way of a detailed and robust survey. The frequency and combinations of products used at specific times during the day will allow the estimation of aggregate exposure for an individual consumer, and to the sample population. In the present study, habits and practices of personal care and cosmetic products have been obtained from market research data for 36,446 subjects across European countries and the United States in order to determine the exposure to fragrance ingredients. Each subject logged their product uses, time of day and body application sites in an online diary for seven consecutive days. The survey data did not contain information on the amount of product used per occasion or body measurements, such as weight and skin surface area. Nevertheless, this was found from the literature where the likely amount of product used per occasion or body measurement could be probabilistically chosen from distributions of data based on subject demographics. The daily aggregate applied consumer product exposure was estimated based on each subject's frequency of product use, and Monte Carlo simulations of their likely product amount per use and body measurements. Statistical analyses of the habits and practices and consumer product exposure are presented, which show the robustness of the data and the ability to estimate aggregate consumer product exposure. Consequently, the data and modelling methods presented show potential as a means of performing ingredient safety assessments for personal care and cosmetics products.


Asunto(s)
Cosméticos , Exposición a Riesgos Ambientales , Modelos Teóricos , Perfumes , Adolescente , Adulto , Anciano , Seguridad de Productos para el Consumidor , Bases de Datos Factuales , Europa (Continente) , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estados Unidos , Adulto Joven
12.
J Phys Condens Matter ; 26(34): 342202, 2014 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-25090658

RESUMEN

We report measurements of Shubnikov-de Haas oscillations in the giant Rashba semiconductor BiTeI under applied pressures up to ∼2 GPa. We observe one high frequency oscillation at all pressures and one low frequency oscillation that emerges between ∼0.3-0.7 GPa indicating the appearance of a second small Fermi surface. BiTeI has a conduction band bottom that is split into two sub-bands due to the strong Rashba coupling, resulting in a 'Dirac point'. Our results suggest that the chemical potential starts below the Dirac point in the conduction band at ambient pressure and moves upward, crossing it as pressure is increased. The presence of the chemical potential above this Dirac point results in two Fermi surfaces. We present a simple model that captures this effect and can be used to understand the pressure dependence of our sample parameters. These extracted parameters are in quantitative agreement with first-principles calculations and other experiments. The parameters extracted via our model support the notion that pressure brings the system closer to the predicted topological quantum phase transition.

13.
Zoonoses Public Health ; 61(2): 105-12, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23663407

RESUMEN

Q fever is a vaccine-preventable disease; despite this, high annual notification numbers are still recorded in Australia. We have previously shown seroprevalence in Queensland metropolitan regions is approaching that of rural areas. This study investigated the presence of nucleic acid from Coxiella burnetii, the agent responsible for Q fever, in a number of animal and environmental samples collected throughout Queensland, to identify potential sources of human infection. Samples were collected from 129 geographical locations and included urine, faeces and whole blood from 22 different animal species; 45 ticks were removed from two species, canines and possums; 151 soil samples; 72 atmospheric dust samples collected from two locations and 50 dust swabs collected from domestic vacuum cleaners. PCR testing was performed targeting the IS1111 and COM1 genes for the specific detection of C. burnetii DNA. There were 85 detections from 1318 animal samples, giving a detection rate for each sample type ranging from 2.1 to 6.8%. Equine samples produced a detection rate of 11.9%, whilst feline and canine samples showed detection rates of 7.8% and 5.2%, respectively. Native animals had varying detection rates: pooled urines from flying foxes had 7.8%, whilst koalas had 5.1%, and 6.7% of ticks screened were positive. The soil and dust samples showed the presence of C. burnetii DNA ranging from 2.0 to 6.9%, respectively. These data show that specimens from a variety of animal species and the general environment provide a number of potential sources for C. burnetii infections of humans living in Queensland. These previously unrecognized sources may account for the high seroprevalence rates seen in putative low-risk communities, including Q fever patients with no direct animal contact and those subjects living in a low-risk urban environment.


Asunto(s)
Coxiella burnetii/aislamiento & purificación , Reservorios de Enfermedades/veterinaria , Microbiología Ambiental , Fiebre Q/epidemiología , Garrapatas/microbiología , Animales , Animales Salvajes , Anticuerpos Antibacterianos/sangre , Gatos , Bovinos , Coxiella burnetii/genética , Coxiella burnetii/inmunología , ADN Bacteriano/aislamiento & purificación , Perros , Heces/microbiología , Caballos , Humanos , Marsupiales , Mascotas , Fiebre Q/microbiología , Queensland/epidemiología , Población Rural , Estudios Seroepidemiológicos , Población Urbana , Zoonosis
14.
Food Chem Toxicol ; 50(6): 2206-15, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22450565

RESUMEN

Many cosmetic products are available in spray form. Even though the principal targets of these products are the skin and hair, spraying leads to the partitioning of the product between the target and the surrounding air. In the previous COLIPA study (Hall et al., 2007) the daily use of deodorant/antiperspirant (Deo/AP) in spray form was quantified in terms of the amount of product dispensed from the spray can, without specifically quantifying the product fraction reaching the skin during use. Results of the present study provide this additional information, necessary for a reliable safety assessment of sprayed Deo/AP products. In a novel experimental approach the information obtained from real-life movement analysis (automated motion imaging) of volunteers using their own products was integrated with the aerosol cloud sampling data obtained from the same products, leading to the computation of the product deposited on the skin. The 90th percentile values, expressed as percent deposition relative to the can weight loss after spraying, are 23.5% and 11.4% for ethanol-based and non-ethanol-based products, respectively. Additionally, the study has generated data on the skin area covered by the products, spray duration time, spray angle and spray distance from the skin.


Asunto(s)
Antitranspirantes/análisis , Desodorantes/análisis , Piel/química , Adulto , Aerosoles , Algoritmos , Simulación por Computador , Cosméticos , Etanol , Femenino , Hábitos , Humanos , Rayos Infrarrojos , Masculino , Persona de Mediana Edad , Modelos Teóricos , Solventes , Adulto Joven
15.
Phys Rev Lett ; 109(24): 246405, 2012 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-23368353

RESUMEN

We report high-magnetic-field (up to 45 T) c-axis thermal-expansion and magnetostriction experiments on URu(2)Si(2) single crystals. The sample length change ΔL(c)(T(HO))/L(c) associated with the transition to the "hidden order" phase becomes increasingly discontinuous as the magnetic field is raised above 25 T. The reentrant ordered phase III is clearly observed in both the thermal expansion ΔL(c)(T)/L(c) and magnetostriction ΔL(c)(B)/L(c) above 36 T, in good agreement with previous results. The sample length is also discontinuous at the boundaries of this phase, mainly at the upper boundary. A change in the sign of the coefficient of thermal expansion α(c)=1/L(c)(∂ΔL(c)/∂T) is observed at the metamagnetic transition (B(M) ~ 38 T), which is likely related to the existence of a quantum critical end point.

16.
Eur J Clin Microbiol Infect Dis ; 30(10): 1287-93, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21499708

RESUMEN

Q fever is a vaccine preventable disease; however, despite this, high notification numbers are still recorded annually in Australia. We investigated the seroprevalence of Coxiella burnetii, the Q fever agent, in a Queensland sample population. Notification data (N = 6425) from 1984-2008 were collated, identifying high risk areas of Q fever exposure. Of these 177 were recorded in children. Serum samples were collected from Queensland and screened using both an immunoflourescence assay at 1:10 dilution and a commercially available ELISA kit. Results were collated based on age, geographical location and sex. From 1988 Queensland samples screened, 103 were identified as Q fever IgG-positive, giving a seroprevalence of 5.2% (95% CI 4.3-6.2%). Seroprevalence in the rural/remote population was 5.3% (95% CI 4.6-6.6%), and the metropolitan Brisbane population, which is considered not at risk, was 5.0% (95% CI 3.7-6.7%). Sixty-three seropositive males and 40 females were identified, along with an increase in seropositivity with increasing age. The seropositivity of children was 1.3% (95% CI 0.7-2.3%) from 844 samples. We have shown that both metropolitan and paediatric populations which are considered low risk of Coxiella exposure have surprisingly high seropositivity. These emerging groups require further investigation and consideration for the introduction of preventive measures.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Coxiella burnetii/inmunología , Fiebre Q/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Ensayo de Inmunoadsorción Enzimática , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Inmunoglobulina G/sangre , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Queensland/epidemiología , Población Rural , Estudios Seroepidemiológicos , Población Urbana , Adulto Joven
17.
Food Chem Toxicol ; 49(2): 408-22, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21093525

RESUMEN

Access to reliable exposure data is essential for the evaluation of the toxicological safety of ingredients in cosmetic products. This study complements the data set obtained previously (Part 1) and published in 2007 by the European cosmetic industry acting within COLIPA. It provides, in distribution form, exposure data on daily quantities of five cosmetic product types: hair styling, hand cream, liquid foundation, mouthwash and shower gel. In total 80,000 households and 14,413 individual consumers in five European countries provided information using their own products. The raw data were analysed using Monte Carlo simulation and a European Statistical Population Model of exposure was constructed. A significant finding was an inverse correlation between the frequency of product use and the quantity used per application recorded for mouthwash and shower gel. The combined results of Part 1 (7 product types) and Part 2 (5 products) reported here, bring up to date and largely confirm the current exposure parameters concerning some 95% of the estimated daily exposure to cosmetics use in the EU. The design of this study, with its relation to demographic and individual diversity, could serve as a model for studies of populations' exposure to other consumer products.


Asunto(s)
Seguridad de Productos para el Consumidor , Cosméticos/administración & dosificación , Cosméticos/efectos adversos , Europa (Continente) , Humanos , Vigilancia de la Población
18.
Rev Sci Instrum ; 80(11): 116101, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19947765

RESUMEN

Thermal expansion, or dilation, is closely related to the specific heat, and provides useful information regarding material properties. The accurate measurement of dilation in confined spaces coupled with other limiting experimental environments such as low temperatures and rapidly changing high magnetic fields requires a new sensitive millimeter size dilatometer that has little or no temperature and field dependence. We have designed an ultracompact dilatometer using an atomic force microscope piezoresistive cantilever as the sensing element and demonstrated its versatility by studying the charge density waves in alpha uranium to high magnetic fields (up to 31 T). The performance of this piezoresistive dilatometer was comparable to that of a titanium capacitive dilatometer.

19.
Food Chem Toxicol ; 45(11): 2086-96, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17804138

RESUMEN

In this study, we describe the statistical analysis of the usage profile of the European population to seven cosmetic products. The aim of the study was to construct a reliable model of exposure of the European population from use of the selected products: body lotion, shampoo, deodorant spray, deodorant non-spray, facial moisturiser, lipstick and toothpaste. The first step in this process was to gather reliable data on consumer usage patterns of the products. These data were sourced from a combination of market information databases and a controlled product use study by the trade association Colipa. The market information study contained a large number of subjects, in total 44,100 households and 18,057 habitual users (males and females) of the studied products, in five European countries. The data sets were then combined to generate a realistic distribution of frequency of use of each product, combined with distribution of the amount of product used at each occasion using the CREMe software. A Monte Carlo method was used to combine the data sets. This resulted in a new model of European exposure to cosmetic products being constructed.


Asunto(s)
Seguridad de Productos para el Consumidor , Cosméticos/administración & dosificación , Cosméticos/efectos adversos , Modelos Biológicos , Europa (Continente) , Humanos , Modelos Estadísticos , Probabilidad
20.
Phys Rev Lett ; 99(2): 027004, 2007 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-17678248

RESUMEN

The interlayer magnetoresistance rho(zz) of the organic metal kappa-(BEDT-TTF)(2)Cu(NCS)(2) is studied in fields of up to 45 T and at temperatures T from 0.5 to 30 K. The peak in rho(zz) seen in in-plane fields, a definitive signature of interlayer coherence, remains to Ts exceeding the Anderson criterion for incoherent transport by a factor approximately 30. Angle-dependent magnetoresistance oscillations are modeled using an approach based on field-induced quasiparticle paths on a 3D Fermi surface, to yield the T dependence of the scattering rate tau(-1). The results suggest that tau(-1) does not vary strongly over the Fermi surface, and that it has a T(2) dependence due to electron-electron scattering.

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