Square Functions for Ritt Operators in L1L^1

$T$ is a Ritt operator in $L^p$ if $\sup_n n\|T^n-T^{n+1}\|<\infty$. From \cite{LeMX-Vq}, if $T$ is a positive contraction and a Ritt operator in $L^p$, $1<p<\infty$, the square function $\left( \sum_n n^{2m+1} |T^n(I-T)^{m+1}f|^2 \right)^{1/2}$ is bounded. We show that if $T$ is a Ritt operator in $L^1$, $$Q_{\alpha,s,m}f=\left( \sum_n n^{\alpha} |T^n(I-T)^mf|^s \right)^{1/s}$$ is bounded $L^1$ when $\alpha+1<sm$, and examine related questions on variational and oscillation norms

Fundamentación y utilización de aproximaciones clásicas en colisiones de iones con átomos

Esta tesis trata sobre los procesos de ionización y capturaelectrónica que ocurren como consecuencia de la colisión de union positivo pesado con un blanco formado por un núcleo pesado yun electrón activo. En el presente trabajo describiremos estosfenómenos mediante aproximaciones totalmente clásicas: losiones pesados proyectil y núcleo blanco son tratados comopartículas clásicas, mientras que la función de onda asociada alelectrón activo es tratada como un fluido clásico. Se presenta una conexión original entre algunasaproximaciones clásicas de la teoría de colisiones y la mecánicacuántica. Esta conexión está basada en la interpretaciónhidrodinámica de la función de onda cuántica. Se precisan lasaproximaciones cuánticas que conducen a una formulaciónsemiclásica de los modelos de Thomson y Monte Carlo detrayectorias clásicas y se definen las funciones de ondaasociadas a los mismos. Se hace una discusión acerca de losprocedimientos que pueden ser utilizados para calcular seccioneseficaces de dispersión. Se muestra que, si se integra laamplitud de transición por unidad de tiempo, se obtiene elcorrecto comportamiento de las secciones eficaces a altasenergías de colisión. También se presenta la implementación numérica del método Monte Carlo de trayectorias clásicas. Se muestran distintasdistribuciones iniciales que pueden utilizarse y se deducen,dentro del formalismo de la ecuación de Liouville, las leyes deescala asociadas a las secciones eficaces clásicas. Se indicacómo tomar muestras representativas de cada una de las posiblesdistribuciones iniciales a ser utilizadas. El método Monte Carlo de trayectorias clásicas es utilizadopara estudiar distintos sistemas colisionantes. Se presentansecciones eficaces totales de ionización y captura electrónicapara colisiones de iones multicargados con blancos de H(1s), He+(1s) y H(2s) y se discute el rango de validez del método. Semuestra que, contrariamente a lo que predice la primeraaproximación de Born, las secciones eficaces totales ysimplemente diferenciales de ionización y excitación no aumentanindefinidamente con la carga del proyectil y se investiga lasaturación de las mismas. También se estudian los sistemas H(+) + He y H(+) + Li(+), los cuales involucran blancos de doselectrones, representando las interacciones mediante potencialesmodelo y dentro del formalismo de electrones independientes. Entodos los casos se obtiene un buen acuerdo con otros modelosteóricos y/o datos experimentales, salvo para la dobleionización de He.This thesis deals with the ionization and electron-captureprocesses that take place as a consecuence of the collisionbetween a heavy positive ion and a target consisting in a heavynucleus and an active electron. Completely classicalapproximations are used to describe these processes: theprojectile and target-nucleus heavy ions are considered to beclassical particles, while the wavefunction associated to theactive electron is treated as a classical fluid. A connection between quantum mechanics and some classicalapproximations is presented. This connection is based on thefluid-dynamical interpretation of the quantum wavefunction. Theclassical trajectory Monte Carlo and Thomson methods are derivedas suitable approximations in a quantum mechanical formalism andthe associated wavefunctions are defined. A discussion is madeabout the procedure to be used to calculate scattering crosssections. It is shown that if the transition amplitude per unittime is integrated, the correct behaviour of the cross sectionsat high collision energies is obtained. The numerical implementation of the classical trajectory Monte Carlo method is also presented. Different initialdistributions that may be used are shown and the scaling lawsassociated with the classical cross sections are deduced withinthe Liouville equation formalism. The way to sample initialconditions representing different initial distributions is alsoshown. The classical trajectory Monte Carlo method is employed tostudy different collision systems. Total ionisation and capturecross sections for fully stripped ions colliding with H(1s), He+(1s) and H(2s) targets are presented and the validity rangeof the classical approximation is discussed. It is shown that,contrarily to the predictions of the first Born approximation,total and single differential ionization and excitation crosssections are bound when the projectile charge is increased. Thesaturation of those cross sections is investigated. The systems H(+) + He and H(+) + Li(+), which involve two-electron targets, are alsostudied by representing the interactions with model potentialsand within the independent-electron formalism. Good agreementis found with other theoretical approximations and/orexperimental data, except for double ionization of He.Fil: Reinhold Larsson, Carlos Oscar. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Innate adaptive immune cell dynamics in tonsillar tissues during chronic SIV infection

HIV-infected patients are at higher risk of developing oral mucosal infection and Epstein–Barr virus (EBV)-associated B cell malignancies. However, the potential role of oral immunity in the pathogenesis of oral lesions is unknown. Tonsils are oral-pharyngeal mucosal-associated lymphoid tissues that play an important role in oral mucosal immunity. In this study, we investigated the changes of innate and adaptive immune cells in macaque tonsils during chronic SIV infection. We found significantly higher frequencies of classical monocytes, CD3+CD56+ (NKT-like) cells, CD3+CD4+CD8+ (DP), and CD161+ CD4 T cells in tonsils from chronic infected compared to naïve animals. On the contrary, intermediate monocytes and CD3+CD4-CD8- (DN) cells were lower in chronic SIV-infected macaques. We further confirmed a recently described small B-cell subset, NKB cells, were higher during chronic infection. Furthermore, both adaptive and innate cells showed significantly higher TNF-α and cytotoxic marker CD107a, while IL-22 production was significantly reduced in innate and adaptive immune cells in chronic SIV-infected animals. A dramatic reduction of IFN-γ production by innate immune cells might indicate enhanced susceptibility to EBV infection and potential transformation of B cells in the tonsils. In summary, our observation shows that the SIV-associated immune responses are distinct in the tonsils compared to other mucosal tissues. Our data extends our understanding of the oral innate immune system during SIV infection and could aid future studies in evaluating the role of tonsillar immune cells during HIV-associated oral mucosal infections

Support for maternal manipulation of developmental nutrition in a facultatively eusocial bee, Megalopta genalis (Halictidae)

Developmental maternal effects are a potentially important source of phenotypic variation, but they can be difficult to distinguish from other environmental factors. This is an important distinction within the context of social evolution, because if variation in offspring helping behavior is due to maternal manipulation, social selection may act on maternal phenotypes, as well as those of offspring. Factors correlated with social castes have been linked to variation in developmental nutrition, which might provide opportunity for females to manipulate the social behavior of their offspring. Megalopta genalis is a mass-provisioning facultatively eusocial sweat bee for which production of males and females in social and solitary nests is concurrent and asynchronous. Female offspring may become either gynes (reproductive dispersers) or workers (non-reproductive helpers). We predicted that if maternal manipulation plays a role in M. genalis caste determination, investment in daughters should vary more than for sons. The mass and protein content of pollen stores provided to female offspring varied significantly more than those of males, but volume and sugar content did not. Sugar content varied more among female eggs in social nests than in solitary nests. Provisions were larger, with higher nutrient content, for female eggs and in social nests. Adult females and males show different patterns of allometry, and their investment ratio ranged from 1.23 to 1.69. Adult body weight varied more for females than males, possibly reflecting increased variation in maternal investment in female offspring. These differences are consistent with a role for maternal manipulation in the social plasticity observed in M. genalis

Atlantic-Mediterranean and within-Mediterranean molecular variation in Coris julis (L. 1758) (Teleostei, Labridae)

Sequence variation in the mitochondrial control region was studied in the Mediterranean rainbow wrasse (Coris julis), a species with pronounced pelagic larval phase inhabiting the Mediterranean Sea and the adjacent coastal eastern Atlantic Ocean. A total of 309 specimens from 19 sampling sites were analysed with the aim of elucidating patterns of molecular variation between the Atlantic and the Mediterranean as well as within the Mediterranean Sea. Phylogeographic analyses revealed a pronounced structuring into a Mediterranean and an Atlantic group. Samples from a site at the Moroccan Mediterranean coast in the Alboran Sea showed intermediate frequencies of “Mediterranean” and “Atlantic” haplotypes. We recognised a departure from molecular neutrality and a star-like genealogy for samples from the Mediterranean Sea, which we propose to have happened due to a recent demographic expansion. The results are discussed in the light of previous studies on molecular variation in fish species between the Atlantic and the Mediterranean and within the Mediterranean

Fundamentación y utilización de aproximaciones clásicas en colisiones de iones con átomos

Esta tesis trata sobre los procesos de ionización y capturaelectrónica que ocurren como consecuencia de la colisión de union positivo pesado con un blanco formado por un núcleo pesado yun electrón activo. En el presente trabajo describiremos estosfenómenos mediante aproximaciones totalmente clásicas: losiones pesados proyectil y núcleo blanco son tratados comopartículas clásicas, mientras que la función de onda asociada alelectrón activo es tratada como un fluido clásico. Se presenta una conexión original entre algunasaproximaciones clásicas de la teoría de colisiones y la mecánicacuántica. Esta conexión está basada en la interpretaciónhidrodinámica de la función de onda cuántica. Se precisan lasaproximaciones cuánticas que conducen a una formulaciónsemiclásica de los modelos de Thomson y Monte Carlo detrayectorias clásicas y se definen las funciones de ondaasociadas a los mismos. Se hace una discusión acerca de losprocedimientos que pueden ser utilizados para calcular seccioneseficaces de dispersión. Se muestra que, si se integra laamplitud de transición por unidad de tiempo, se obtiene elcorrecto comportamiento de las secciones eficaces a altasenergías de colisión. También se presenta la implementación numérica del método Monte Carlo de trayectorias clásicas. Se muestran distintasdistribuciones iniciales que pueden utilizarse y se deducen,dentro del formalismo de la ecuación de Liouville, las leyes deescala asociadas a las secciones eficaces clásicas. Se indicacómo tomar muestras representativas de cada una de las posiblesdistribuciones iniciales a ser utilizadas. El método Monte Carlo de trayectorias clásicas es utilizadopara estudiar distintos sistemas colisionantes. Se presentansecciones eficaces totales de ionización y captura electrónicapara colisiones de iones multicargados con blancos de H(1s), He+(1s) y H(2s) y se discute el rango de validez del método. Semuestra que, contrariamente a lo que predice la primeraaproximación de Born, las secciones eficaces totales ysimplemente diferenciales de ionización y excitación no aumentanindefinidamente con la carga del proyectil y se investiga lasaturación de las mismas. También se estudian los sistemas H(+) + He y H(+) + Li(+), los cuales involucran blancos de doselectrones, representando las interacciones mediante potencialesmodelo y dentro del formalismo de electrones independientes. Entodos los casos se obtiene un buen acuerdo con otros modelosteóricos y/o datos experimentales, salvo para la dobleionización de He.This thesis deals with the ionization and electron-captureprocesses that take place as a consecuence of the collisionbetween a heavy positive ion and a target consisting in a heavynucleus and an active electron. Completely classicalapproximations are used to describe these processes: theprojectile and target-nucleus heavy ions are considered to beclassical particles, while the wavefunction associated to theactive electron is treated as a classical fluid. A connection between quantum mechanics and some classicalapproximations is presented. This connection is based on thefluid-dynamical interpretation of the quantum wavefunction. Theclassical trajectory Monte Carlo and Thomson methods are derivedas suitable approximations in a quantum mechanical formalism andthe associated wavefunctions are defined. A discussion is madeabout the procedure to be used to calculate scattering crosssections. It is shown that if the transition amplitude per unittime is integrated, the correct behaviour of the cross sectionsat high collision energies is obtained. The numerical implementation of the classical trajectory Monte Carlo method is also presented. Different initialdistributions that may be used are shown and the scaling lawsassociated with the classical cross sections are deduced withinthe Liouville equation formalism. The way to sample initialconditions representing different initial distributions is alsoshown. The classical trajectory Monte Carlo method is employed tostudy different collision systems. Total ionisation and capturecross sections for fully stripped ions colliding with H(1s), He+(1s) and H(2s) targets are presented and the validity rangeof the classical approximation is discussed. It is shown that,contrarily to the predictions of the first Born approximation,total and single differential ionization and excitation crosssections are bound when the projectile charge is increased. Thesaturation of those cross sections is investigated. The systems H(+) + He and H(+) + Li(+), which involve two-electron targets, are alsostudied by representing the interactions with model potentialsand within the independent-electron formalism. Good agreementis found with other theoretical approximations and/orexperimental data, except for double ionization of He.Fil: Reinhold Larsson, Carlos Oscar. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina