1,368 research outputs found
Mapping responses to frequency sweeps and tones in the inferior colliculus of house mice
No full text23 novembre : Soutenance de thèse de Charles Ehret
No full textM. Charles Ehret soutiendra sa thèse de doctorat "Agir en vertu d'un autre. Thomas d'Aquin et l'ontologie de l'instrument" devant un jury composé de Jean-Baptiste Brenet - Université Paris 1-Panthéon-Sorbonne Cristina Cerami - CNRS Robert Pasnau - University of Colorado, Boulder Pasquale Porro - Université Paris-Sorbonne Marwan Rashed - Université Paris-Sorbonne Cecilia Trifogli - All Souls College, Oxford * le jeudi 23 novembre, à 14h en Sorbonne, EPHE, Salle Duroselle (plan d'accès) 14, r..
Audio-vocal interaction in the pontine brainstem during self-initiated vocalization in the squirrel monkey
No full textEnergy-momentum tensor from Wilson flow in lattice φ4-theory
No full textThe energy-momentum tensor (EMT) is the Noether current associated with
translations. It is of interest because, first of all, it has physical meaning as it
contains the energy density and the momentum density. Moreover, its trace can
be related to the beta function so that the scaling behaviour of the theory at
hand can be studied. We are particularly interested in the scaling behaviour of
strongly coupled theories. To explore the strong coupling regime it is necessary
to compute the EMT non-perturbatively, i.e. on the lattice. This complicates
matters greatly. On the lattice translation invariance is broken which leads to
additional terms in the translation Ward identity from which the EMT is derived.
This results in turn in the need to renormalise the EMT on the lattice.
In this thesis we extend recent studies on the renormalisation of the EMT
in four-dimensional gauge theory to the case of a three-dimensional scalar
theory to investigate its divergence structure and the numerical feasibility of the
suggested procedure on a more basic level. Furthermore, scalar φ4-theory in three
dimensions exhibits an infrared fixed point and can thus serve as a toy model to
examine mechanisms for building theories beyond the standard model.
Our strategy to renormalise the EMT on the lattice is to identify all possible terms
that can mix with both sides of the translation Ward identity. The renormalised
EMT is a combination of operators of the same or lower dimension obeying
the symmetries of the theory. The mixing is determined by requiring that the
renormalised EMT satisfies the correct Ward identities. Using different probes
in the translation Ward identity one can compute the coefficients of the EMT
by solving a linear system of equations. However, contact terms can arise. One
solution is the recently introduced Wilson flow. Its renormalisation properties allow for expectation values free of contact terms. That way the Wilson flow provides for a meaningful theoretical formulation of the EMT on the lattice that can be used in practice.
In this thesis we review the renormalisation properties and the phase diagram
of scalar φ4-theory in three dimensions, the translation Ward identity and the
EMT in the continuum, as well as the gradient flow for scalar theory. A large
part is dedicated to the perturbative renormalisation of the EMT on the lattice.
Finally, our strategy to compute the renormalisation constants of the EMT in
scalar theory non-perturbatively is discussed in detail, and our results for the
renormalisation constants are presented
Occurrence, Distribution and Polymerase Chain Reaction-Based detection of resistance to Sterol Demethylation Inhibitor Fungicides in populations of Blumeriella jaapii in Michigan.
No full textThe intensive use of site-specific fungicides in agricultural production
provides a potent selective mechanism for increasing the frequency of
fungicide-resistant isolates in pathogen populations. Practical resistance
occurs when the frequency and levels of resistance are great enough to
limit the effectiveness of disease control in the field. Cherry leaf spot
(CLS), caused by the fungus Blumeriella jaapii, is a major disease of
cherry trees in the Great Lakes region. The site-specific sterol demethylation
inhibitor fungicides (DMIs) have been used extensively in the region.
In 2002, CLS control failed in a Michigan orchard that had used the DMI
fenbuconazole exclusively for 8 years. That control failure and our observations
from around the state suggested that practical resistance had developed
in B. jaapii. Field trial data covering 1989 to 2005 for the DMIs
fenbuconazole and tebuconazole supported observations of reduced efficacy
of DMIs for controlling CLS. To verify the occurrence of fungicideresistant
B. jaapii, monoconidial isolates were collected in two surveys
and tested using a fungicide-amended medium. In one survey, 137
isolates from sites with different DMI histories (no known history, mixed
or alternated with other fungicides, and exclusive use) were tested against
12 concentrations of fenbuconazole, tebuconazole, myclobutanil, and
fenarimol. Isolates from sites with no prior DMI use were DMI sensitive
(DMIS = no colony growth at 0.2 μg/ml a.i.) whereas the isolates from the
site with prior exclusive use showed growth at DMI concentrations 3 to
>100 times higher, and were rated as DMI resistant (DMIR). A second
survey examined 1,530 monoconidial isolates, including 1,143 from 62
orchard sites in Michigan, where DMIs had been used to control CLS.
Resistance to fenbuconazole was detected in 99.7% of the orchard isolates.
All isolates from wild cherry trees were sensitive and isolates from
feral and dooryard trees showed a range of sensitivities. A polymerase
chain reaction (PCR)-based detection method for identifying B. jaapii
and DMIR was developed and tested. The species-specific primer pair (Bj-
F and Bj-R) based on introns in the CYP51 gene of B. jaapii, and the
DMIR-specific primer pair (DMI-R-Bj-F and DMI-R-Bj-R) based on an
insert found upstream of CYP51 in all DMIR isolates, provided an accurate
and rapid method for detecting DMIR B. jaapii. The PCR-based identification
method will facilitate timely decision making and continued
monitoring of DMIR subpopulations in response to management programs
Length scales in the tear resistance of soft tissues and elastomers: a comparative study based on computational models
No full textFracture toughness describes a material’s ability to resist failure in the presence of defects. In case of soft biological tissues, a reliable determination and interpretation of the fracture properties is essential to estimate the risk of fracture after clinical interventions. Here we perform a comparative computational study between soft biological tissues and compliant elastomers to discuss the influence of material non-linearity on the crack tip nearfield. Using detailed finite element simulations, singular near-tip stress fields are obtained, and a so-called nonlinear region is identified. Additional focus is put on the effect of material nonlinearity on the phenomenon of elastic crack blunting, by analysing the deformed crack profile and extracting a radius of curvature at the tip. Through concepts of traditional fracture mechanics, we identify the size of the process zone and nonlinear elastic zone in biological tissues, juxtaposed with that of elastomers, demonstrating the limitations of the traditional metrics in capturing the remarkable defect tolerance of this highly nonlinear material class
Night, Mother Cast List
No full textCast list for 'Night, Mother by Marsha Norman, directed by Don Ehret on May 11 & 13, 1993, and including a note from the play's author
Bioenergy provision by an alley cropping system of grassland and shrub willow hybrids: biomass, fuel characteristics and net energy yields
No full textIn the temperate zone, alley cropping is promoted as a climate change-resilient agroforestry practice for the provision of biogenic energy carriers. However, little information is available on the potential of such cropping systems as feedstock for biofuel production. In a field trial in Central Europe, the triennial performance of alley cropping systems was assessed. The systems consisted of clover-grass, a native diversity-oriented grassland mixture and multirows of willows. They were compared to a willow and grassland control adjacent to the trial area. Three different conversion technologies were applied to grassland feedstock and analyzed for relevant quality parameters. Net energy balances were calculated to determine the potential of the cropping systems and the associated controls as providers of biogenic energy carriers. The grassland control had the highest triennial yield (18 t DM ha(-1)), whereas pure willow stands were less productive with 7 t DM ha(-1). Alley cropping was intermediate with 12 t DM ha(-1) on average. Net energy yield of the clover-grass based systems was highest in the grassland control for all conversion technologies, whereas values of the diversity-based systems in the control and the alley cropping system achieved similar values. This study only investigated the first 3 years after establishment, when growth rates of shrub willows were still low. Thus, more research is needed to evaluate the long-term performance of agroforestry systems with shrub willows and herbaceous crops.German Ministry of Education and Research (BMBF
Estudo das ligas intermetalicas Cu33AL67 e Fe33Sn67 nanoestruturadas preparadas por mechanical alloying
No full textDissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas.Este trabalho é parte de um amplo projeto de pesquisa sobre materiais nanoestruturados fabricados por Mechanical Alloying que o Grupo de Física do Estado Sólido da UFSC vem realizando. As ligas Fe33Sn67 e CU33Al67 possuem grande importância tecnológica. Devido as elevadas diferenças nos pontos de fusão dos elementos químicos, a obtenção destas ligas pelas técnicas convencionais apresentam grandes dificuldades, sendo estas superadas quando a técnica Mechanical Alloying é utilizada para a fabricação das mesmas. As técnicas de difração de raios-x e calorimetria diferencial de varredura (DSC) foram usadas no estudo das propriedades estruturais destas ligas. Os difratogramas de difração de raios-x da liga Fe33Sn67 tal como coletada e tratada termicamente foram indexados a uma rede tetragonal denominada de fase , com parâmetros de rede a = b = 6,5234 Â e c = 5,3373 Â e, a = b = 6,5369 A e c = 5,3328 Â, respectivamente. O tamanho médio encontrados para os cristalitos foram L = 164 A e L = 297 A, respectivamente. Os padrões de difração de raios-x da liga CU33Al67 tal como foi coletada e tratada termicamente foram indexados a uma rede tetragonal denominada de fase O, com parâmetros de rede a = b = 6,0636 Â e c = 4,8848 Â e, a = b =6,0547 Â e c = 4,8719 Â, respectivamente e a uma rede cúbica de face centrada (alumínio) com parâmetros de rede a = 4,0994 Â e a = 4,0993 Â, respectivamente. O tamanho médio calculados para os cristalitos da fase tetragonal foram L = 80 Â e L = 358 Â e, para a rede fc.c. foram L = 109 Â e L = 360 Â. O tratamento térmico precipitou uma nova fase na liga CU33Al67, sendo esta, possivelmente, monoclínica com o tamanho médio dos cristalitos em tomo de L = 294 A. Portanto, neste trabalho, obtemos ligas com uma estrutura nanométrica. O programa DBWS, utilizado para simular padrões de difração de raios-x, confirmou a presença da fase tetragonal nestas ligas e de alumínio metálico na liga CU33Al67 nanoestruturada
- …
