302 research outputs found
Hearing loss and fluctuating hearing levels in X-linked hypophosphataemic osteomalacia
Abstract Background and objective: X-linked hypophosphataemic osteomalacia is the most common of the genetically determined forms of osteomalacia. The occurrence of hearing loss in X-linked hypophosphataemic osteomalacia has been known since 1984. However, observations on the progression of such hearing loss, and suggestions regarding possible therapy, have not previously been published. Methods: Case report of a patient with X-linked hypophosphataemic osteomalacia and hearing loss, with three years' audiological follow up, description of empirical therapy and literature review. Results: The patient presented with fluctuating hearing. An audiogram showed mild to severe sensorineural hearing loss mainly in the low and high frequencies. A temporary improvement of 20-40dB after steroid therapy was observed. Four weeks later, hearing had deteriorated again, mainly in the low frequencies. After one year of fluctuating hearing levels, stabilisation occurred. Conclusions: In X-linked hypophosphataemic osteomalacia, hearing loss occurs predominantly in the low and high frequencies. The hearing loss type and progression pattern point to an endolymphatic hydrops as the pathogenetic mechanism. Steroid therapy may be of some benefi
Where the electroweak phase transition ends
We give a more precise characterisation of the end of the electroweak phase
transition in the framework of the effective 3d SU(2)--Higgs lattice model than
has been given before. The model has now been simulated at gauge couplings
beta_G=12 and 16 for Higgs masses M_H^*=70, 74, 76 and 80 GeV up to lattices
96^3 and the data have been used for reweighting. The breakdown of finite
volume scaling of the Lee-Yang zeroes indicates the change from a first order
transition to a crossover at lambda_3/g_3^2=0.102(2) in rough agreement with
results of Karsch et al (hep-lat/9608087) at \beta_G=9 and smaller lattices.
The infinite volume extrapolation of the discontinuity Delta
/g_3^2 turns out to be zero at lambda_3/g_3^2=0.107(2) being an upper limit. We
comment on the limitations of the second method.Comment: RevTeX, 19 pages, 11 figures, 2 tables; additional MC-data near the
endpoint considere
Planilha eletrônica para o cálculo da reflectância em imagens TM e ETM+ LANDSAT.
A reflectância de culturas agrĂcolas e de outros alvos da superfĂcie terrestre Ă© um parâmetro intrĂnseco dos objetos sensoriados e, assim, em muitas situações, deve ser utilizada em lugar dos valores de nĂveis de cinza normalmente encontrados nas imagens de satĂ©lite. Para obter a reflectância de alvos de imagens de satĂ©lite Ă© necessário eliminar a interferĂŞncia atmosfĂ©rica e realizar uma sĂ©rie de cálculos que envolvem parâmetros do sensor e informações da prĂłpria imagem. Automatizar esse procedimento tem como vantagens a agilização do processo e a redução dos riscos de erros durante os cálculos. O objetivo do presente artigo Ă© apresentar uma planilha eletrĂ´nica que simplifica e automatiza a transformação dos nĂşmeros digitais das imagens TM e ETM+ dos satĂ©lites Landsat 5 e 7 em valores de reflectância, isto Ă©, um parâmetro intrĂnseco dos objetos sensoriados e, portanto, com significado fĂsico. O mĂ©todo de correção atmosfĂ©rica empregado Ă© o da subtração de objeto escuro ou DOS. A planilha eletrĂ´nica aqui descrita pode ser encontrada no endereço eletrĂ´nico http://www.dsr.inpe.br/Calculo_Reflectancia.xls e pode ser utilizada para calcular valores de reflectância em imagens dos sensores Landsat TM e ETM+
Endpoint of the hot electroweak phase transition
We give the nonperturbative phase diagram of the four-dimensional hot
electroweak phase transition. The Monte-Carlo analysis is done on lattices with
different lattice spacings (). A systematic extrapolation is done.
Our results show that the finite temperature SU(2)-Higgs phase transition is of
first order for Higgs-boson masses GeV. At this endpoint the
phase transition is of second order, whereas above it only a rapid cross-over
can be seen. The full four-dimensional result agrees completely with that of
the dimensional reduction approximation. This fact is of particular importance,
because it indicates that the fermionic sector of the Standard Model can be
included perturbatively. We obtain that the Higgs-boson endpoint mass in the
Standard Model is GeV. Taking into account the LEP Higgs-boson
mass lower bound excludes any electroweak phase transition in the Standard
Model.Comment: Latex, 7 pages, 4 figure
Three-Dimensional Electronic Structure of type-II Weyl Semimetal WTe
By combining bulk sensitive soft-X-ray angular-resolved photoemission
spectroscopy and accurate first-principles calculations we explored the bulk
electronic properties of WTe, a candidate type-II Weyl semimetal featuring
a large non-saturating magnetoresistance. Despite the layered geometry
suggesting a two-dimensional electronic structure, we find a three-dimensional
electronic dispersion. We report an evident band dispersion in the reciprocal
direction perpendicular to the layers, implying that electrons can also travel
coherently when crossing from one layer to the other. The measured Fermi
surface is characterized by two well-separated electron and hole pockets at
either side of the point, differently from previous more surface
sensitive ARPES experiments that additionally found a significant quasiparticle
weight at the zone center. Moreover, we observe a significant sensitivity of
the bulk electronic structure of WTe around the Fermi level to electronic
correlations and renormalizations due to self-energy effects, previously
neglected in first-principles descriptions
Spatial Re-Establishment Dynamics of Local Populations of Vectors of Chagas Disease
Chagas disease is transmitted by blood-sucking bugs (vectors) and presents a severe public health threat in the Americas. Worldwide there are approximately 10 million people infected with Chagas disease, a disease for which there is currently no effective cure. Vector suppression is the main strategy to control the spread of this disease. Unfortunately, the vectors have been resurgent in some areas. It is important to understand the dynamics of reinfestation where it occurs. Here we show how different models fitted to patch-level bug infestation data can elucidate different aspects of re-establishment dynamics. Our results demonstrated a 6-month time lag between detection of a new infestation and dispersal events, seasonality in dispersal rates and effects of previous vector infestation on subsequent vector establishment rates. In addition we provide estimates of dispersal distances and the effect of insecticide spraying on rates of vector re-establishment. While some of our results confirm previous findings, the effects of season and previous infestation on bug establishment challenge our current understanding of T. infestans ecology and highlight important gaps in our knowledge of T. infestans dispersal
Goodness-of-Fit Tests for Symmetric Stable Distributions -- Empirical Characteristic Function Approach
We consider goodness-of-fit tests of symmetric stable distributions based on
weighted integrals of the squared distance between the empirical characteristic
function of the standardized data and the characteristic function of the
standard symmetric stable distribution with the characteristic exponent
estimated from the data. We treat as an unknown parameter,
but for theoretical simplicity we also consider the case that is
fixed. For estimation of parameters and the standardization of data we use
maximum likelihood estimator (MLE) and an equivariant integrated squared error
estimator (EISE) which minimizes the weighted integral. We derive the
asymptotic covariance function of the characteristic function process with
parameters estimated by MLE and EISE. For the case of MLE, the eigenvalues of
the covariance function are numerically evaluated and asymptotic distribution
of the test statistic is obtained using complex integration. Simulation studies
show that the asymptotic distribution of the test statistics is very accurate.
We also present a formula of the asymptotic covariance function of the
characteristic function process with parameters estimated by an efficient
estimator for general distributions
Molecular epidemiology of clinical isolates of Pseudomonas aeruginosa isolated from horses in Ireland
Clinical isolates (n = 63) of Pseudomonas aeruginosa obtained from various sites in 63 horses were compared using ERIC2 RAPD PCR to determine their genetic relatedness. Resulting banding patterns (n = 24 genotypes) showed a high degree of genetic heterogeneity amongst all isolates examined, indicating a relative non-clonal relationship between isolates from these patients, employing this genotyping technique. This study characterised 63 clinical isolates into 24 distinct genotypes, with the largest cluster (genotype E) accounting for 10/63 (15.9%) of the isolates. ERIC2 RAPD PCR proved to be a highly discriminatory molecular typing tool of P. aeruginosa in isolates recovered from horses. With the adoption of several controls to aid reproducibility, this technique may be useful as an alternative to PFGE, particularly in epidemiological investigations of outbreaks where speed may be a significant parameter. This is the first report of clonal heterogeneity amongst P. aeruginosa from horses and demonstrated that ERIC RAPD PCR is a rapid method for the examination of this species in horses, which may be useful in outbreak analysis
A Genetic Variation of Lipopolysaccharide Binding Protein Affects the Inflammatory Response and Is Associated with Improved Outcome during Sepsis
LPS binding protein (LBP) is an important innate sensor of microbial cell wall structures. Frequent functionally relevant mutations exist and have been linked to influence susceptibility to and course of bacterial infections. We examined functional properties of a single nucleotide polymorphism resulting in an exchange of phenylalanine to leucine at position 436 of LBP (rs2232618) and compared the frequent variant of the molecule with the rare one in ligand binding experiments. We then stimulated RAW cells with bacterial ligands in the presence of serum obtained from individuals with different LBP genotypes. We, furthermore, determined the potential effects of structural changes in the molecule by in silico modeling. Finally, we analyzed 363 surgical patients for this genetic variant and examined incidence and course of sepsis following surgery. We found that binding of LBP to bacterial ligands was reduced, and stimulation of RAW cells resulted in an increased release of TNF when adding serum from individuals carrying the F436L variant as compared with normal LBP. In silico analysis revealed structural changes of LBP, potentially explaining some of the effects observed for the LBP variant. Finally, patients carrying the F436L variant were found to be similarly susceptible for sepsis. However, we observed a more favorable course of severe infections in this cohort. Our findings reveal new insights into LPS recognition and the subsequent activation of the innate immune system brought about by LBP. The identification of a genetic variant of LBP influencing the course of sepsis may help to stratify individuals at risk and thus reduce clinical complications of patients.Peer Reviewe
Comparison of Renormalization-Group and Lattice Studies of the Electroweak Phase Transition
We compare the results of renormalization-group and lattice studies for the
properties of the electroweak phase transition. This comparison reveals the
mechanisms that underlie the phenomenology of the phase transition.Comment: 13 pages, 3 figure
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