We present reverberation mapping results from the first year of combined spectroscopic and photometric observations of the Sloan Digital Sky Survey Reverberation Mapping Project. We successfully recover reverberation time delays between the g+i band emission and the broad H beta emission line for a total of 44 quasars, and for the broad Ha emission line in 18 quasars. Time delays are computed using the JAVELIN and CREAM software and the traditional interpolated cross-correlation function (ICCF): using well-defined criteria, we report measurements of 32 H beta and 13 Ha lags with JAVELIN, 42 H beta and 17 Ha lags with CREAM, and 16 H beta and eight Ha lags with the ICCF. Lag values are generally consistent among the three methods, though we typically measure smaller uncertainties with JAVELIN and CREAM than with the ICCF, given the more physically motivated light curve interpolation and more robust statistical modeling of the former two methods. The median redshift of our H beta-detected sample of quasars is 0.53, significantly higher than that of the previous reverberation mapping sample. We find that in most objects, the time delay of the Ha emission is consistent with or slightly longer than that of H beta. We measure black hole masses using our measured time delays and line widths for these quasars. These black hole mass measurements are mostly consistent with expectations based on the local M-BH-sigma* relationship, and are also consistent with single-epoch black hole mass measurements. This work increases the current sample size of reverberation-mapped active galaxies by about two-thirds and represents the first large sample of reverberation mapping observations beyond the local universe (z < 0.3).

Investigação da estrutura de núcleos exóticos é uma área bastante ativa da Física Nuclear atual. O desenvolvimento dessa área foi acentuado com a possibilidade de uso de feixes radioativos. Inspirados nessa possibilidade, laboratórios espalhados pelo mundo estão se desenvolvendo para produzir feixes radioativos de núcleos cada vez mais ricos em prótons ou em nêutrons. O uso de elementos radioativos como feixes têm oferecido oportunidades novas e únicas para pesquisa em física nuclear. Questões fundamentais tais como qual a natureza da matéria nuclear e como elementos pesados são sintetizados em novas, supernovas e estrelas de nêutrons podem ser abordadas em investigações utilizando-se feixes radioativos. Neste trabalho abordamos a produção de alguns desses feixes na região de massa A=10 e 15, especificamente, 10Be, 12B, 14C e 15C. Descrevemos métodos de produção e aplicamos simulações para produção de feixes com esses núcleos. Abordamos as peculiaridades na produção de cada um deles com o intuito de produzir feixes o mais intenso e puros possíveis. Nas simulações utilizamos a plataforma Lise++ baseada em método de Monte Carlo e foi dada ênfase na utilização de um sistema de duplo-solenoides. As simulações foram comparadas com resultados experimentais obtidos com esse sistema para os feixes de 12B e 14C, onde um bom acordo foi obtido. / Nuclear Structure Investigations of exotic nuclei is currently a very active area of Nuclear Physics. Many laboratories around the world are developing their system to produce radioactive beams of nuclei rich in protons or neutrons. The use of these radioactive elements as beams has offered new and unique opportunities for research in nuclear physics. Fundamental questions such as what the nature of nuclear matter is and how heavy elements are synthesized in novae, supernovae and neutron stars can be addressed in investigations using radioactive beams. In this work we address the production of some of these beams in the region of mass A = 10 and 15, specifically 10Be, 12B e 14,15C. We describe production methods and apply simulations using the plataforma Lise++ with Monte Carlo method. We addressed the peculiarities related to the production of each of them, in the sense to get the most intense and pure secondary radioactive beams possible. In the simulations, emphasis was given to the use of a double-solenoid system. The simulations were compared with experimental results obtained with these systems for the 12B and 14C beams, where a good agreement was obtained.

Cálculos dos espectros (E,J ) e das propriedades eletromagnéticas (U,Q,BE2,BM1) são realizados para isótopos ímpares do Ni, e isótopos ímpares com N=82, empregando o modelo de camadas (MC), a aproximação BCS usual (uma e três quasipartículas), BCS com blocking (BBCS) e BCS projetada (PBCS). São examinadas, em detalhe, a importância das correlações de cinco quasipartículas e das correções introduzidas em BCS. Os graus de liberdade coletivos do caroço são introduzidos através do acoplamento quasipartículas cluster vibrador (ACQPV), de modo que nosso formalismo possibilita tanto a inclusão de blocking como a projeção em número de partículas no cluster de uma e três quasipartículas. São realizados cálculos comparativos entre a versão com blocking (BQPCV) e com projeção (PQPCV) para os espectros e as propriedades eletromagnéticas de isótopos ímpares do Zn. A versão projetada é aplicada a isótopos do Césio, na descrição dos estados 5/2+ gerados pelo acoplamento anômalo. / We calculate nuclear spectra (E,J ) and electromagnetic properties (U,,BE2,BM1) for odd Ni isotopes and N=82 odd nuclei, using the shell model (MC), the usual BCS approximation (one and three quasiparticles ), blocking (BBCS) and projected (PBCS) BCS. The effects of five quasiparticles correlations and BCS corrections are carefully investigated. We introduce the core collective degrees of freedom by the quasiparticle- cluster- vibration coupling (ACQPV) , in such a way that our treatment makes possible to introduce both blocking and particle- number- projection in one and three quasiparticle cluster. Blocking (BQPCV) and projected (PQPCV) versions are compared for spectra and electromagnetic properties of odd Zn isotopes . Projected version is applied to Cs isotopes, in order to describe the 5/2+ states generated by anomalous coupling.

Numerous factors play a role in the development and maintenance of North Atlantic tropical cyclones as they originate and cross the Main Development Region. These factors include sea-surface temperatures (SSTs), relative humidity, vertical wind shear, etc. One key player in many of these factors is the Saharan Air Layer (SAL) which has been a source for study for nearly five decades. The interplay between dust loading within the SAL and the development of African Easterly Waves (AEWs) has been repeatedly noted in many of the studies in this field. The cumulative indirect effect of the dust on AEWs however remains unknown (Evan et al., 2006a). On a case by case basis, the SAL has been shown to negatively influence the development of AEWs, i.e. entrainment of dry air into the low to mid-levels, enhanced vertical wind shear and suppression of convection within the storm (Dunion & Velden, 2004). Positive influences on AEW development have also been attributed to the SAL, namely its enhancement of the African Easterly Jet (AEJ) which in turn helps produce positive vorticity along its southern edge that AEWs tap into for energy (Karyampudi & Pierce, 2002). Further study is indeed warranted to try to fully understand whether or not the SAL has a positive or negative influence on the development of AEWs. A polarized view may be inadequate, as the SAL’s role could very well be positive, negative or somewhere in between depending on the storm characteristics and environmental conditions present at that unique time. This study looked into the role dust loading has on the mixing between the SAL and the moist marine boundary layer directly beneath the base of the SAL, which can range from 500 – 1500m and revealed a dynamic and varying relationship. It also demonstrated, through a decrease in cloud top temperatures, that dust levels are associated with the convective strength of AEWs by acting as cloud condensation nuclei (CCNs). However this association can be nullified through other parameters unique to each individual storm; SSTs, vertical wind shear, dry-air entrainment, etc.

Alzheimer´s disease (AD) is an age-related, irreversible and progressive neurodegenerative pathology that deteriorates cognitive function including learning and memory. AD is characterised neuropathologically by the presence of neuritic plaques (Aβ), neurofibrillary tangles (NFTs), synaptic loss and neuronal death. AD affects specific brain regions involved in mnestic function such as the neocortex and the hippocampus. The dorsal (DR) and the median raphe (MR) nuclei give rise to serotonergic (5-HT) projections that innervate multiple brain regions including the cortex and the hippocampus, playing an important role in learning and memory processes. For a long time the degeneration of cholinergic (ACh) system was considered as the main neurochemical changes in AD brains, however, more recent studies highlight the involvement of other neurotransmitter systems including 5-HT. This thesis entitled “Altered serotonergic neurotransmission as a main player in the pathophysiology of Alzheimer’s disease: structural and ultrastructural studies in a triple transgenic mouse model of the disease” demonstrates that there exist specific alterations in the serotonergic projections of the hippocampus during the progression of AD using the triple transgenic (3xTg-AD) mouse model of the disease, which closely resemble human AD. Mr. Harun N. Noristani is submitting this thesis to the University of Manchester for the degree of PhD in the Faculty of Life Science. The results obtained in this thesis show for the first time a biphasic increase in serotonergic fibre sprouting in the 3xTg-AD mouse model of AD that occurs in parallel with evident intraneuronal/extracellular Aβ deposition in the hippocampus (Chapter 3). In addition, serotonergic fibre sprouting correlated with reduced perforated synapses in the hippocampus, suggesting a structural remodeling process to maintain hippocampal connectivity (Chapter 4). Increased 5-HT neurotransmission (via high dietary intake of tryptophan, 5-HT precursor) reduced intraneuronal Aβ accumulation in the hippocampus, suggesting a direct role of 5-HT neurotransmission in modifying AD neuropathology (Chapter 5). Given the protective role of increased 5-HT neurotransmission, treatment with 5-HT enhancing drugs may be beneficial in reducing the underlying pathology as well as improving the behavioural and cognitive abnormalities associated with AD. Nevertheless, the role of specific 5-HT receptors responsible for such neuro-protective effect of 5-HT in AD awaits further research.

No description available.

NMR spectroscopy has evolved into one of the most important characterization techniques in chemistry with which it is possible to obtain valuable structural, dynamical, and mechanistic information. Most applications of NMR have however been limited to the use of nuclei having spin quantum numbers of 1/2. This thesis discusses the developments that have been advanced in order to extract quantitative structural information from the NMR spectroscopy of quadrupolar nuclei (spin, I>1/2) which account for the vast majority of the NMR-active nuclei. In a first part of the thesis, a NMR crystallographic method is developed which uses the electric field gradient tensor measured at the nuclear sites as an experimental constraint in DFT-based crystal structure refinements. This inclusion of experimental data into crystal structure refinements enables the determination of higher quality, and experimentally-relevant, structures. We apply this new methodology in order to determine higher quality crystal structures for the non-linear optical material Na2B2Al2O7, sodium pyrophosphates, and the near-zero thermal expansion material ZrMgMo3O12. In a second part of this thesis, experimental techniques are developed for the measurement of spin-spin coupling between pairs of quadrupolar nuclei; the measurement of spin-spin coupling carries with it extremely valuable distance and connectivity information. Using DOR NMR, heteronuclear residual dipolar coupling as well as homonuclear J coupling multiplets can be observed. Notably, the J coupling between quadrupolar nuclei can still be measured in A2 spin systems, unlike in the case of pairs of spin-1/2 nuclei. The theory that was developed for the characterization of these multiplets was extended for the general simulation of exact NMR spectra of quadrupolar. This program, known as QUEST, is now free to use by anyone in the scientific community. Pulsed J-resolved NMR experiments are then described which enable the facile measurement of J and dipolar coupling in homonuclear pairs of quadrupolar nuclei. Notably, the J splitting is greatly amplified in A2 spin systems which provides strong structural information and enables the precise detection of smaller J coupling constants. These techniques are applied towards directly studying gallium metal-metal bonding interactions as well as boron-boron bonds in diboron compounds of importance in β-boration chemistry.

La théorie covariance de la fonctionnelle de la densité (CDF), basée sur un petit nombre de paramètres ajustables, a été utilisée avec succès pour décrire l’état fondamental et les états excités des noyaux de la carte nucléaire, pour A>12. Cette approche permet de décrire les systèmes nucléaires finis avec un Lagrangien hadronique universel résolu dans le cadre de l'approche Relativiste-Hartree-Fock-Bologuibov (RHFB). Ce modèle est également utilisé pour l'étude des étoiles compactes, car il peut être étendu à des densités élevées où la relativité restreinte ne peut pas être ignoré. Ce modèle peut également être étendu pour inclure la contribution des hypérons et ainsi que d'autres particules exotiques. Dans ce travail, la description et des prédictions basées sur l'approche RHFB pour les noyaux dans des conditions extrêmes de la masse, d'isospin et de température sont présentés.Dans la première partie de cette thèse, nous explorons l'apparition de nouvelles fermetures de couches sphériques pour des noyaux super-lourds, où les fermetures de couches sont caractérisées en termes de gap à deux nucléons. Les résultats dépendent légèrement des Lagrangians effectifs utilisés, mais les nombres magiques au-delà de ^{208} Pb sont prédit pour un nombre de protons Z=120 et 138, et pour un nombre de neutrons N=172, 184, 228, et 258. Les effets de couche sont sensibles à différents termes de champ de moyen, tels que le couplage spin-orbite, la masse scalaire et la masses effective, ainsi que l'interaction de tensorielle de Lorentz. Ces termes ont des poids différents dans les Lagrangians effectifs employées, expliquant les variations, somme toute petites, dans leurs prédictions. Employant le modèle RHFB le plus avancé, nous avons trouvé que le nucléide ^{304} 120 est favorisée comme étant le prochain noyau sphérique doublement magique au-delà de ^{208} Pb.Dans la deuxième partie de cette thèse, nous étudions l'apparition de nouveaux nombres magiques pour les noyaux de masse intermédiaire riches en neutrons, et nous analysons le rôle des interactions pseudo-vecteur et de tensorielle de Lorentz. Basé sur la transformation de Foldy-Wouthuysen, nous discutons en détail le rôle joué par les différents termes des interactions pseudo-vecteur et de tensorielle de Lorentz. Dans l'apparition des nouveaux nombres magiques N=16 , 32 et 34. Les noyaux ^{24} O ^{48} Si et ^{52,54} Ca sont prédits avec un grand gap au niveau de Fermi et un gap d'appariement zéro (^{24} O,^{54}Ca ) ou quasi-nul (^{48} Si,^{54} Ca), les rendant candidats pour de nouveaux nombres magiques des noyaux riches en neutrons. Nous constatons que les interactions de Lorentz pseudo-vecteur et tensorielle induisent des évolutions très spécifiques des énergies à une particule, ce qui pourrait signer la présence et la nécessité d'approches relativistes avec des interactions d'échanges de mésons.Dans la dernière partie de cette thèse, nous étudions les transitions de phase et excitations thermiques des deux noyaux stables et faiblement liés. Les prédictions de divers Lagrangiens relativistes et des différentes interactions d'appariement sont discutées. La température critique de la transition d'appariement dépend linéairement du gap d'appariement à température nulle, et cette dépendance est similaire pour une interaction de portée nulle ou bien finie. Les calculs présentés montrent des caractéristiques intéressantes des corrélations d'appariement à température finie, comme la persistance d'appariement et les phénomènes de re-entrance superfluide. En outre, nous analysons la réponse thermique de certains noyaux.En conclusion, le travail présenté dans cette thèse montre des résultats très intéressants et nouveaux pour trois des questions les plus importantes en physique nucléaire: la quête d'un nouvel îlot de stabilité dans la région des super-lourds, l'apparition de nouveaux nombres magiques dans les noyaux exotiques, et la réponse d'un système finis aux excitations thermiques. / The covariant density functional (CDF) theory with a few number of parameters has been successfully employed to describe ground-state and excited-states of nuclei over the entire nuclear landscape for A > 12. It describes finite nuclear systems with a universal hadronic Lagrangian, which is solved considering the relativistic-Hartree-Fock-Bologuibov approach (RHFB). This model is also employed for the study of compact stars, since it can be extended to high densities where special relativity cannot be ignore. This model can also be extended to include the contribution of hyperons and as well as other exotic particles. In this work, the description and some predictions based on RHFB approach for nuclei under extreme conditions of mass, isospin and temperature are presented.In the first part, we explore the occurrence of spherical shell closures for superheavy nuclei, where shell closures are characterized in terms of two-nucleon gaps. The results depend slightly on the effective Lagrangians used, but the magic numbers beyond ^{208}Pb are generally predicted to be Z = 120 and 138 for protons, and N = 172, 184, 228, and 258 for neutrons. Shell effects are sensitive to various terms of the mean-field, such as the spin-orbit coupling, the scalar and the effective masses, as well as the Lorentz-tensor interaction. These terms have different weights in the effective Lagrangians employed, explaining the (relatively small) variations in the predictions. Employing the most advanced RHFB model, we founded that the nuclide ^{304}120 is favored as being the next spherical doubly-magic nucleus beyond ^{208}Pb.In the second part, we investigate the formation of new shell gaps in intermediate mass neutron-rich nuclei, and analyze the role of the Lorentz pseudo-vector and tensor interactions. Based on the Foldy-Wouthuysen transformation, we discuss in detail the role played by the different terms of the Lorentz pseudo-vector and tensor interactions in the appearance of the N=16, 32 and 34 shell gaps. The nuclei ^{24}O, ^{48}Si and ^{52,54}Ca are predicted with a large shell gap and zero (^{24}O, ^{52}Ca) or almost zero (^{48}Si, ^{54}Ca) pairing gap, making them candidates for new magic numbers in neutron rich nuclei. We find that the Lorentz pseudo-vector and tensor interactions induce very specific evolutions of single-particle energies, which could clearly sign their presence and reveal the need for relativistic approaches with exchange interactions.In the last part, we study the phase transitions and thermal excitations of both stable and weakly-bound nuclei. The predictions of various relativistic Lagrangians and different pairing interactions are discussed. The critical temperature of the pairing transition is found to depend linearly on the zero-temperature pairing gap, and this dependence is similar for a zero-range or a finite-range pairing interaction. The present calculations show interesting features of the pairing correlations at finite temperature, such as the pairing persistence and pairing re-entrance phenomena. Also, we analyze the thermal response of some nuclei.In conclusion, the work presented in this thesis shown interesting and new results for three of the most important questions in nuclear physics: the quest for a new island of stability in the superheavy region, the appearance of new magic numbers in exotic nuclei, and the response of finite-systems to thermal excitations.

<div><div><div><p>Determining the locations of nuclei in Zebrafish embryos is crucial for the study of the spatio-temporal behavior of these cells during the development process. With image seg- mentations, not only the location of the cell can be known, but also determine if each pixels is background or part of a nucleus. Traditional image processing techniques have been thor- oughly applied to this problem. These techniques suffer from bad generalization, many times relying on heuristic that apply to a specific type of image to reach a high accuracy when doing pixel by pixel segmentation. In previous work from our research lab, wavelet image segmentation was applied, but heuristics relied on expected nuclei size .</p><p>Machine learning techniques, and more specifically convolutional neural networks, have recently revolutionized image processing and computer vision in general. By relying on vast amounts of data and deep networks, problems in computer vision such as classification or semantic segmentation have reached new state of the art performance, and these techniques are continuously improving and pushing the boundaries of state of the art.</p><p>The lack of labeled data to as input to a machine learning model was the main bottleneck. To overcome this, this work utilized Amazon Turk platform. This platform allows users to create a task and give instructions to ‘Workers‘ , which agree to a price to complete each task. The data was preprocessed before being presented to the workers, and revised to make sure it was properly labeled.</p><p>Once labeled data was ready, the images and its corresponding segmented labels were used to train a U-Net model. In a nutshell, this models takes the input image, and at different scales, maps the image to a smaller vector. From this smaller vector, the model , again at different scales, constructs an image from this vector. During model training, the weights of the model are updated so that the image that is reconstructed minimizes the difference between the label image and the pixel segmentation.</p><p>We show that this method not only fits better the labeled ground truth image by the workers, but also generalizes well to other images of Zebrafish embryos. Once the model is trained, inference to obtain the segmented image is also orders of magnitude faster than previous techniques, including our previous wavelet segmentation method.</p></div></div></div>

Philosophiae Doctor - PhD / The Coulomb excitation of 66Ge has been performed for the rst time using \safe" bombarding energies at the HIE-ISOLDE facility at CERN in July 2017. A particle- coincidence experiment using the MINIBALL array and double-sided silicon detectors has allowed the determination of transitional and diagonal matrix elements in 66Ge, yielding new measurements of the reduced transition probability connecting the ground state, 0+1 , and the rst excited state, 2+1 , or B(E2; 2+1 ! 0+1 ) value, and the spectroscopic quadrupole moment of the 2+1 state, QS (2+1 ). A relatively large B(E2) = 29:4(30) W.u. has been extracted using beam-gated data at forward angles { less sensitive to secondorder e ects { as compared with the adopted value of 16:9(7) W.u., but in closer agreement with modern large-scale shell-model calculations using a variety of e ective interactions and beyond-mean eld calculations presented in the current work. / 2022