Quark matter production in heavy-ion collisions

The study of high-energy heavy-ion collisions is presently a very active field in experimental particle physics, with the RHIC collider at BNL in operation since summer 2000 and with the ALICE experiment being prepared to study this kind of physics at LHC energies. The first goal of these experimental attempts, which started in 1986, with the AGS and SPS fixed-target programs, is the discovery of the phase transition from confined hadronic matter to deconfined partonic matter. The idea that such a phase transition should exist, between hadronic and quark matter, has been around since the first models of the quark structure of hadrons. It is presently studied in detail in the framework of lattice QCD calculations, which predict its occurrence when the temperature of the system exceeds a critical threshold at around 170 MeV, corresponding to a critical energy density of around 600 MeV/fm3 [1]

Assessing the effort of exercise using low cost sensors

In this work, it is proposed a solution that tries to help the physical education teachers in the assessment of their students, also trying to increase the motivational levels of students with the inclusion of new technologies in class, and with the fact that the presented metric, being estimated for each student from their own effort. It is proposed a solution that uses a sensor, in this case an accelerometer, in order to capture accelerometry data during the execution of four physical activities: volleyball, handball, basketball and futsal. Data was retrieved from two classes of the 9thº Portuguese school year. The device used to capture those accelerometry data was the student’s own smartphones, through a mobile application that collects data and sends it to a server. After that data is uploaded, it is analysed in order to calculate the metric Running Equivalent of Activity (REA). An empiric study was developed aiming at the experimental validation of the metric referred above, having been followed diverse experimental protocols. A set of good practices is suggested for the adoption of the proposed solution, a mean to enable a fair and equitable assessment of the effort applied by the students during the physical education classes.No presente trabalho é proposta uma solução que visa ajudar os professores de educação física a fazer a avaliação dos seus alunos, e os alunos a sentirem-se mais motivados com a inclusão de tecnologia nas aulas de educação física e com o facto da métrica apresentada, ser calculada a partir do esforço de cada um, tentando assim ultrapassar alguns vieses inerentes ao processo de avaliação. Foi proposta uma solução que utiliza um sensor, neste caso o acelerómetro, para a obtenção de dados de acelerometria durante a execução de quatro atividades físicas: voleibol, andebol, basquetebol e futsal. Foram recolhidos dados de duas turmas que frequentam o 9º ano. O dispositivo utilizado para a obtenção desses valores de acelerometria foi o smarpthone dos alunos, através de uma aplicação móvel que é responsável pela recolha dos dados e por os enviar para um servidor. Esses dados foram sintentizados e analisados de forma a calcular a métrica Running Equivalent of Activity (REA). Foi realizado um estudo empírico que visa a validação experimental da referida métrica tendo sido testados diversos protocolos experimentais. São sugeridas um conjunto de boas práticas para a adopção da solução ora proposta, no sentido de permitir uma aferição justa e equitativa do esforço aplicado pelos estudantes nas aulas de Educação Física

NRQCD colour-octet expansion vs. LHC quarkonium production: signs of a hierarchy puzzle?

info:eu-repo/semantics/publishedVersio

Details and big pictures consumer use of actual prices and price images when choosing a store

In this paper, we develop a model of consumer patronage decisions to evaluate the effect of store price images vis-à-vis that of objective basket prices. Within this dual retail price model, the two types of price information are linked through the dynamic formation of price images over time, itself based on actual prices. We show that not accounting for the effect of (dynamic) price perceptions may seriously bias store traffic estimation in response to price changes. Finally, we explore which demographic and shopping characteristics of consumers may explain or shed light on differences in sensitivity to different price information.info:eu-repo/semantics/publishedVersio

Big data analytics for intra-logistics process planning in the automotive sector

The manufacturing sector is facing an important stage with Industry 4.0. This paradigm shift impulses companies to embrace innovative technologies and to pursuit near-zero fault, near real-time reactivity, better traceability, and more predictability, while working to achieve cheaper product customization. The scenario presented addresses multiple intra-logistic processes of the automotive factory Volkswagen Autoeuropa, where different situations need to be addressed. The main obstacle is the absence of harmonized and integrated data flows between all stages of the intra-logistic process which leads to inefficiencies. The existence of data silos is heavily contributing to this situation, which makes the planning of intra-logistics processes a challenge. The objective of the work presented here, is to integrate big data and machine learning technologies over data generated by the several manufacturing systems present, and thus support the management and optimisation of warehouse, parts transportation, sequencing and point-of-fit areas. This will support the creation of a digital twin of the intra-logistics processes. Still, the end goal is to employ deep learning techniques to achieve predictive capabilities, all together with simulation, in order to optimize processes planning and equipment efficiency. The work presented on this thesis, is aligned with the European project BOOST 4.0, with the objective to drive big data technologies in manufacturing domain, focusing on the automotive use-case

Deciphering the structural features of glycan-lectin interactions in the immune system

This thesis is focused on the study of the molecular recognition of two cancer associated glycan epitopes, the LacdiNAc (GalNAcβ1-4GlcNAc) and the LacNAc (Galβ1-4GlcNAc) structures by two immune-related lectins, the human macrophage galactose-type lectin (MGL) and human galectin-3 (Gal-3) through a multidisciplinary approach that combines NMR spectroscopy, isothermal titration calorimetry (ITC), molecular dynamics (MD) and X-ray crystallography. In the case of the MGL, the KD of MGL/LacdiNAc complex is at low µM range (5.3 µM) and similar that obtain for the MGL/α-Me-GalNAc complex, while MGL/LacNAc complex is at the mM range (higher than 1 mM). STD-NMR binding studies demonstrate that MGL preferentially binds LacdiNAc and LacNAc structures, through the non-reducing end of the disaccharides. The 1H,15N-HSQC based titrations show that both ligands perturb the same region of MGL, however, the magnitude of this perturbation is much higher in the case of LacdiNAc than LacNAc. Furthermore, significant differences in the chemical shift perturbations of Y236, H286 and D294 residues were observed. MD models show that these differences are intimately related with the specific engagement of the NHAc group of the GalNAc unit of LacdiNAc. With respect of Gal-3 complexes both ligands bind Gal-3 with similar affinity (30-40 µM). Nevertheless, the 1H,15N-HSQC based titration shows that additional residues are perturbed in βstrand S3 in the case of Gal-3/LacdiNAc complex. X-Ray structure of the complex Gal-3/LacdiNAc confirms modifications at this region of the protein showing that the LacdiNAc induces an alternate conformation for the side chain of R144. The R144B conformation, absent in the case of the complex with LacNAc, mediates a hydrogen-bond with the N-acetyl group of GalNAc of LacdiNAc, and increase the residence of a water molecule (W2) that in turn establish a hydrogen-bond network involving the N-acetyl group of GalNAc, the glycosidic bond of LacdiNAc and the R144B.Esta tese está focada no estudo do reconhecimento molecular de dois epítopos de açúcares que estão associados ao cancro, o LacdiNAc (GalNAcβ1-4GlcNAc) e o LacNAc (Galβ1-4GlcNAc) por duas lectinas do sistema imunitário, a human macrophage galactose-type lectin (MGL) e a human Galectin-3 (Gal-3) através de uma estratégia multidisciplinar que combina espetroscopia de RMN, calorimetria de titulação isotérmica (ITC), dinâmica molecular (MD) e cristalografia de raios-X. No caso da MGL, o KD do complexo MGL/LacdiNAc é na ordem dos baixos μM (5.3 μM), semelhante ao obtido para o complexo MGL/α-Me-GalNAc, enquanto que o complexo MGL/LacNAc é na ordem do mM (acima de 1mM). Os estudos de interação por STD-RMN demonstram que a MGL liga preferencialmente ao LacdiNAc e LacNAc através da unidade não redutora dos dissacáridos. As titulações baseadas em 1H,15N-HSQC mostram que ambos os ligandos perturbam a mesma região da MGL, no entanto, a magnitude da perturbação é muito superior no caso do LacdiNAc que no do LacNAc. Além disso, foram observadas diferenças significativas nas perturbações de desvio químico de Y236, H286 e D294. Os modelos de MD atribuem essas diferenças à interação específica do grupo NHAc da unidade de GalNAc do LacdiNAc. No que respeita aos complexos da Gal-3, ambos os ligandos têm afinidades semelhantes (30-40 μM). Ainda assim, as titulações baseadas em 1H,15N-HSQC evidenciam que há resíduos adicionais perturbados na β-strand S3 no caso do complexo Gal-3/LacdiNAc. A estrutura de raios-X do complexo Gal-3/LacdiNAc confirma as modificações nesta região da proteína, mostrando que o LacdiNAc induz uma conformação alternada da cadeia lateral da R144. A conformação R144B, ausente no caso do complexo com LacNAc, media uma ponte de hidrogénio com o grupo N-acetil do GalNAc do LacdiNAc, e aumenta a residência de uma molécula de água (W2) que estabelece uma rede de pontes de hidrogénio que envolve o grupo N-acetil do GalNAc, a ligação glicosídica do LacdiNAc e a R144B

Particle Polarization in High Energy Physics

This open-access book addresses the following questions: how does the polarization of a particle, i.e., the angular momentum state in which it is produced, manifest itself in nature? What are the concepts and tools needed to perform rigorous measurements providing complete and unambiguous physical information? Polarization measurements are important because they reflect the nature and coupling properties of a particle and provide unique insights into the underlying fundamental interactions, playing a central role in the study and understanding of the mechanisms of particle production. Besides gradually reviewing many fundamental notions, the book presents several case studies relevant to physics analyses underway at the LHC, including the lepton-antilepton decays of vector states (Drell–Yan, Z and W bosons, quarkonia, etc.). The book also offers a detailed discussion of cascade decays, where the vector particle is a daughter of another particle, as well as a survey of typical angular distributions of particles of any integer or half-integer spin. With a visual approach to the presentation of the concepts and frequent use of pedagogical examples, taken from real measurements, gedankenexperiments, or detailed simulations, the book focuses on aspects of polarization measurements that are sometimes underestimated or left unexplored in experimental analyses, such as the importance of the choice of the reference frame, the existence of frame-independent relations, and the shapes of the physically allowed parameter domains. Several examples are provided of pitfalls introduced when the intrinsic multidimensionality of the problem is neglected in exchange for a simplified analysis. Targeting an audience of graduate students, post-docs, and other researchers involved in analyses of LHC data, this book helps to establish a solid bridge between high precision data, existing or soon to be collected, and accurate measurements, including high-sensitivity tests of the Standard Model

Open questions in quarkonium and electromagnetic probes

In my ("not a summary") talk at the Hard Probes 2006 conference, I gave "a personal and surely biased view on only a few of the many open questions on quarkonium and electromagnetic probes". Some of the points reported in that talk are exposed in this paper, having in mind the most important of all the open questions: do we have, today, from experimental data on electromagnetic probes and quarkonium production, convincing evidence that shows, beyond reasonable doubt, the existence of "new physics" in high-energy heavy-ion collisions?Comment: Invited talk at the 2nd Int. Conf. on Hard and EM Probes of High-Energy Nuclear Collisions, Asilomar, California, June 9--16, 2006. To be published in Nuclear Physics A. Late submission to the arXi

The Terceira Rift, Azores: a melt inclusion study of submarine lavas

The Azores plateau, a bathymetric high, is seated on an anomalous mantle domain located in the Azores Triple Junction where the American, EUR and AFR lithospheric plates meet. The cause for these anomalies is controversial but many authors consider the presence of an anomalously hot/wet enriched mantle probably supplied by a plume [3]. The origin, size and present location of the plume is under debate but an area near Terceira is the favoured plume centre [2]. The Terceira Rift (TR) defines the EUR/AFR plate boundary of the Azores triple junction. The TR is a 550 km long, generally ESE trending line of volcanic massifs along the axis (e.g. São Miguel, D. João de Castro, Terceira and Graciosa) alternating with deep basins (e.g. Hirondelle basin) interpreted as volcanically unfilled rift valley segments [3]. Vesicular, porphyritic basalts were sampled along the Terceira Rift during Portuguese scientific cruises (EMEPC 2007-2009). Initial studies focused on the adjacent areas Don João de Castro - DJC (submarine volcano) and Hirondelle - Hir (basin). Major and trace element data of phenocrysts (olivine, clinopyroxene, plagioclase), groundmass and exposed melt inclusions found in these vesicular lavas depict only slight differences between the two sites. DJC samples depict higher Fo and Mg# in olivine and clinopyroxene, respectively. Chondrite-normalized REE data indicate that groundmass material is LREE-enriched in both Hir and DJC lavas. Exposed melt inclusions (MI) show similar REE patterns compared to their hosts. Clinopyroxene in both sites display L-MREE enriched, HREE depleted sinusoidal patterns. MI were found in olivine, clinopyroxene and plagioclase phenocrysts. MI are glassy to completely opaque and devitrified, with one or more bubbles, and sulfide globules (SG). SG are spherical, depict two-phase lamellar intergrowths of Fe-Ni and Cu-Fe phases, and are ubiquitous in DJC and Hir lava samples. Some lavas display SG within clinopyroxene-hosted MI and dispersed in the groundmass. Preliminary data suggest that lavas found in these areas of the Terceira Rift were sulfur-saturated in different stages of their evolution; during early fractionation and prior to eruption. The geochemistry of melt inclusion will contribute to the understanding of mantle source, melting and mixing processes in the Terceira Rift, Azores