Median inverse problem and approximating the number of kk-median inverses of a permutation

We introduce the "Median Inverse Problem" for metric spaces. In particular, having a permutation $\pi$ in the symmetric group $S_n$ (endowed with the breakpoint distance), we study the set of all $k$-subsets $\{x_1,...,x_k\}\subset S_n$ for which $\pi$ is a breakpoint median. The set of all $k$-tuples $(x_1,...,x_k)$ with this property is called the $k$-median inverse of $\pi$. Finding an upper bound for the cardinality of this set, we provide an asymptotic upper bound for the probability that $\pi$ is a breakpoint median of $k$ permutations $\xi_1^{(n)},...,\xi_k^{(n)}$ chosen uniformly and independently at random from $S_n$

"Sobre" Guimarães Rosa: anotações para a leitura do conto "Os Chapéus Transeuntes"

II Jornadas Latino-Americanas de Linguagens e Cultura. Em comemoração aos 100 anos de nascimento de Roa Bastos e 50 anos da morte de Guimarães RosaApós apresentar informações introdutórias com respeito a “Os Chapéus Transeuntes”, a comunicação indaga possíveis motivos para o conto ser tão pouco estudado até hoje, concluindo que, ao atravessar vida e obra de Guimarães Rosa, essa estória especificamente é elemento fundamental para a compreensão da biobibliografia do autor mineiro.Programa de Pós-Graduação em Literatura Comparada Programa de Pós-Graduação Interdisciplinar em Estudos Latino-Americanos Curso de Graduação em Letras – Artes e Mediação Cultura

Age and gender classification: A proposed system

With the new General Data Protection Regulation, there has been a lot of concerns when it comes to saving personal and sensitive data. As a result, there is a necessity to gather information without storing any data that could be considered sensitive, and that could identify the person to which it belongs to. Our motivation was to create a system that could be used to gather information about the people that visit commercial areas, using their surveillance systems as input to the application. In the present work, we developed a system capable of gathering age and gender information from people based on images, using Deep Learning. Such system was built using a face detection model based on the GoogLeNet deep neural network and on a Wide Residual Network for age and gender classification, supported by a Siamese Network for the latter. The outcome is, to the best of our knowledge, the first available implementation that makes use of Wide Residual Networks and Siamese Networks at the same time for gender classification.Com o aparecimento do Regulamento Geral de Proteção de Dados, têm surgido várias preocupações no que diz respeito ao armazenamento de dados sensíveis e pessoais de clientes. Com isto, surge a necessidade de obter informação sem guardar quaisquer dados sensíveis que possam identificar a pessoa aos quais dizem respeito. Um exemplo, que serviu de motivação para o trabalho desenvolvido nesta dissertação, é o de uma aplicação que requeira a criação de modelos que sejam capazes de recolher informação acerca do tipo de pessoas que frequenta determinadas áreas comerciais, utilizando os seus sistemas de vigilância como dados de entrada para essa aplicação. No presente trabalho foi desenvolvido um sistema com o intuito de obter dados, nomeadamente a idade e género, através da utilização de imagens, utilizando para isso técnicas de Deep Learning. Este sistema é constuído por um modelo de detecção de pessoas baeado no modelo GoogLeNet e, para a classificação de idades e género, por uma Wide Residual Network, suportada por uma Rede Siamesa no que diz respeito à classificação de género. Para além da criação de um sistema capaz de classificar idades e género a partir de imagens de forma integrada, no melhor do nosso conhecimento, esse sistema constitui a primeira implementação disponível que utiliza Wide Residual Networks em conjunto com Redes Siameses para o problema específico da classificação de género

How can forecasting and analysing competition and tourism indicators be applied into setting a dynamic pricing range. An organizational challenge of Indie campers

Indie Campers is a fast growing Start Up – one of the biggest in the Portuguese tourism sector – and, whenever new decisions are on deck to be taken, historical experience, metadata and business environment need to be assessed and analysed firstly to mitigate the risk of new decisions and secondly to adjust expectations and target the right measures. While settling position and expanding, the Start Up’s activity carries many new decisions oftentimes and, as Indie Campers, from year to year has grown, changed and evolved remarkably, some decision analysis deterrents need to be faced and diverted as accurately as possible. Being dynamic pricing one main strategic decision for 2018, internal metadata and external analysis are crucial to assert a well-defined quantitative price strategy and a well-informed qualitative value proposition. The deterrents that are challenged and recommended upon are the lack of adequate internal metadata – adequate in a sense that expansion and growth have increased in such a way that raw data from homologous periods is fairly incomparable – that makes it hard for the company to compare data and apply it to yearly forecast; the lack of resources – being time one of the most valuable, due to scalability and fast-moving growth – that makes it hard for the company to assess macro and micro indicators to understand the environment in which Indie Campers will be competing in and, ultimately, the lack of tools and models to apply in the future that, combined, make setting dynamic pricing a comprehensive and mark-up decision

Roles of human VRK1 Ser-Thr kinase in the regulation of cell proliferation

[EN] Cell proliferation and cell differentiation are different mechanisms occurring at different times of the cell life. However, the regulation of the switch from proliferation to differentiation and the role and fate of proliferation-related proteins are mostly unknown. Cell division is a high-regulated mechanism, involving several kinases, namely Vaccinia-related kinase 1 (VRK1) and Aurora kinase B (AurKB). These kinases assure the correct transmission of genetic information to the newly-formed cells, DNA replication, chromosome segregation and chromatin condensation. VRK1 is the first member of the VRK family and is ubiquitously expressed in all the tissues, especially high-proliferative tissue, including liver and thymus or cancer cells. Therefore, based on VRK1 features and expression, its role has been mostly related to the regulation of cell proliferation, including the regulation of transcription factors involved in cell cycle progression and DNA damage repair pathways, modulation of p53 levels, nuclear envelope assembly, Cajal body (CB) formation and maintenance, and fragmentation of the Golgi apparatus. Apart from these, VRK1 also contributes to the mitotic chromatin condensation through histone H3 phosphorylation, mainly, in the Thr3 residue (H3T3ph). H3T3ph is especially important for the formation, localization and function of the chromosomal passenger complex (CPC) on the centromeres, during mitosis. (see group publications). In turn, AurKB is a member of the aurora kinase family, alongside with AurKA and AurKC. The activity of this family of kinases is fulfilled during mitosis, and therefore, they are mitotic kinases critical for the mitotic regulation of centromere function, chromatin condensation, spindle assembly, chromosome alignment and segregation and, cytokinesis. AurKB is a component of CPC, along with Survivin, Borealin and INCENP and contributes to chromatin condensation, through H3S10 phosphorylation. On the other hand, the transcriptional factor (TF) Sox2, a member of the SRY-related HMG-box family of TFs is a master regulator of pluripotency, proliferation, survival and differentiation of embryonic stem cell (ESC). Moreover, Yamanaka’s factor Sox2 is a cancer initiating cell biomarker in poorly differentiated or undifferentiated cancers, since these types of cancers have been characterized by many phenotypic traits similar to undifferentiated embryonic stem cells. Indeed, Sox2 is overexpressed in numerous tumors like breast cancer and lung cancer or in cancer cell lines suggesting the enormous oncogenic potential of this TF. It is also important to notice, that Sox2 combines with Oct4 to control cell cycle, through cyclin D1 promoter activation. Finally, also macro-histone H2A (macroH2A) can regulate cell differentiation and cell proliferation. Macro H2A (macroH2A1.1, macroH21.2 and macroH2A2) are histones variant that can replace conventional histone H2A in the nucleosomes, repressing cell proliferation genes and favoring cell differentiation genes. These histone variants change the chromatin conformation, affecting TFs binding and creating de novo activation and repression binding sites. It was also reported that macroH2A variants could regulate VRK1 levels. Initially, we observe that VRK1 is a chromatin kinase, besides its usual nucleo-plasmatic and cytoplasmatic localization, and interacts with the histone H3 by immuprecipitation (IP) and ‘’Pull-down’’ assays in early mitosis. Moreover, VRK1 phosphorylates directly the mitotic H3T3, as observed by kinase assay with cold ATP and phospho-specific antibodies. Next and focusing on VRK1 and AurKB relationship we observed that VRK1 and AurKb inhibits the kinase activity of one another, as observed by kinase assay with radiolabeled ATP. Moreover, increasing doses of VRK1, active or inactive, affected negatively the phosphorylation of AurKB-specific residue S10 on histone H3 in kinase assay with cold ATP. Besides, also increasing doses of AurKB, active and inactive, affected negatively the phosphorylation of H3T3 and the phosphorylation of p53T18 by VRK1. This effect is consequence of the formation of a stable complex between the two protein kinases and independent of any type of phosphorylation of one kinase on another. By IP and ‘’Pull-down’’ assay we observed that transfected VRK1 and transfected AurKB interact, forming a stable complex independent of VRK1 activity. VRK1 interacts with AurKB through both amino and carboxy terminals. The interaction between endogenous VRK1 and AurKB occurs in early mitosis, after cell arrest with nocodazole. Yet, no co-localization between the two kinases was observed by immunofluorescence (IF). Moreover, VRK1 downregulation affected the localization of AurKB in early mitosis in IF assays. VRK1 downregulation avoids centromeric accumulation of AurKB, leading to a more diffuse distribution on the chromatin. This result is due to the loss of H3T3 phosphorylation, as observed by IF and western blot (WB). Loss of VRK1-dependent H3T3 phosphorylation affects the interaction of AurKB with Histone H3 in IP assays. Regarding VRK1 and reprogramming factors, VRK1 and Sox2 distribution was analyzed by immunohistochemistry on a stratified squamous epithelium and it was observed that Sox2 and VRK1 co-localize in the undifferentiated layers of the epithelium. The same result was observed by IF in several cell lines, such as NTera-2 (NT2), MCF-7 or MDA-MB-231. Moreover, VRK1 and Sox2 interact in IP assay. The interaction occurs between transfected proteins and between endogenous proteins, and it is through both VRK1 amino and carboxy terminals. Sox2 is a phosphorylation target of VRK1 as determined by kinase assay with radiolabelled ATP. Sox2, as a regulator of cell proliferation regulates proliferative genes, including VRK1. SOX2 regulates VRK1 promoter in luciferase assays, increasing, when overexpressed, the RNA and protein levels of the kinase, as observed by qRT-PCR, WB and IF. The result was observed in NT2, MDA-MB-231 and MCF-7 cell line. In turn, VRK1 downregulation increases RNA (qRT-PCR) and protein levels (IF and WB) of Sox2 in NT2, MDA-MB-231 and MCF-7, creating a feedback loop between VRK1 and Sox2. The overexpression of VRK1 produced the opposite result. Furthermore, VRK1 and Sox2 cooperate in the activation of CCND1 gene, in luciferase assays potentiating proliferation. After induction of cell differentiation with retinoic acid, both Sox2 and VRK1 RNA and protein are downregulated and they are absent or significantly down-regulated in terminally differentiated epithelial cells. In terminally differentiated cells, macroH2A variants 1.2 and 2 repress VRK1 and CCND1 gene promoter, as determined by luciferase assay. In conclusion, VRK1 participates in the regulation of cell proliferation, through two new and independent mechanisms. One by actively regulating AurKB and the other by regulating the balance between cell proliferation and cell differentiation

Caracterização das comunidades de polinizadores e plantas da Universidade de Aveiro: primeiro passo para uma gestão sustentável

The creation of urban green spaces is one way to mitigate the impact of the human population and cities. Despite the benefits that urban green spaces have, these spaces are subject to constant disturbance, allowing only the survival of species that are adapted to such conditions. Proper management of these spaces is one of the ways to optimize and preserve their potential biodiversity and ecosystem services. The University of Aveiro Campi has several habitats that are subject to these disturbances. Thus, arose the need to characterize each habitat, namely the relationships between plants and insect pollinators, in order to provide a baseline for the elaboration of appropriate management plans to improve these habitats and its biodiversity. The main objective of this study was to characterize the plant and insect pollinator communities of three habitats of the University of Aveiro: the seminatural meadow of the Campus Universitário de Santiago, the salt pan of Santiago da Fonte and the artificial “pseudo-dune” formation of ECOMARE. As a secondary objective, this study aimed to analyse the threats of the three sampled habitats and provide possible management measures that could allow an improvement and a better conservation of these habitats and ecosystem services. We sampled 156 plant species and 194 insect species, in which 92 (47.4%) were classified as pollinators. The semi-natural meadow presented a greater floristic richness, as well as of insect pollinators. In this habitat, it was observed that of the 170 insect species found here, 43 showed preference for a specific group of plant species. The sampled habitats harbour distinct plant and insect pollinator communities, and several associations between insect and plant species, especially in the semi-natural meadow. As suggestions for sustainable management, we highlight the need to control invasive plants, as they pose a threat to local biodiversity, as well as to mow the vegetation in a heterogeneous manner, maintaining high vegetation mosaics with the permanence of flowering species, as well as places for egg deposition and shelter.A criação de espaços verdes urbanos é uma das formas de mitigar o impacto da população humana e das cidades. Apesar dos benefícios que os prados verdes urbanos possam trazer, estes locais estão sujeitos a constantes perturbações, que apenas permite a sobrevivência de espécies que estejam adaptadas a tais condições. Uma gestão correta destes espaços é uma das formas de otimizar e preservar a sua biodiversidade potencial e os serviços de ecossistema. Os Campi da Universidade de Aveiro albergam diversos habitats que estão sujeitos essas perturbações. Assim, surgiu a necessidade de caracterizar cada habitat, nomeadamente as relações entre as plantas e os insetos polinizadores, de forma a providenciar uma base para a elaboração de planos de gestão adequados ao melhoramento destes habitats e da sua biodiversidade. Este estudo teve como objectivo principal a caracterização do elenco florístico e da comunidade de insetos polinizadores de três habitats da Universidade de Aveiro: o prado seminatural do Campus Universitário de Santiago, as salinas Santiago da Fonte e a formação artificial “pseudo-dunar” do ECOMARE. Como objectivo secundário, este estudo pretendeu analisar as ameaças aos três habitats e fornecer possíveis medidas de gestão que permitiram um melhoramento e uma melhor conservação destes habitats e dos serviços de ecossistema. Foram amostradas 156 espécies de plantas e 194 espécies de insetos, nos quais 92 (47.4%) foram classificadas como polinizadores. O prado seminatural apresentou uma maior riqueza florística, bem como de insetos polinizadores. Neste habitat, foi observado que das 170 espécies de insetos aqui encontrados, 43 demonstravam preferência por um grupo exclusivo de espécies de plantas. Os habitats estudados albergam comunidades de plantas e de insetos polinizadores distintas entre si, sendo que, alguns insetos demonstraram uma preferência por algumas espécies de plantas, especialmente no prado seminatural. Como sugestões de gestão sustentável, são realçadas a necessidade de controlar as plantas invasoras, pela ameaça que estas colocam à biodiversidade local, bem como realizar o corte da vegetação de forma heterogénea, mantendo mosaicos de vegetação alta com permanência de espécies em floração, bem como locais de abrigo e postura.Mestrado em Ecologia Aplicad

Practical characterization of quantum devices without tomography

Quantum tomography is the main method used to assess the quality of quantum information processing devices, but its complexity presents a major obstacle for the characterization of even moderately large systems. The number of experimental settings required to extract complete information about a device grows exponentially with its size, and so does the running time for processing the data generated by these experiments. Part of the problem is that tomography generates much more information than is usually sought. Taking a more targeted approach, we develop schemes that enable (i) estimating the fidelity of an experiment to a theoretical ideal description, (ii) learning which description within a reduced subset best matches the experimental data. Both these approaches yield a significant reduction in resources compared to tomography. In particular, we demonstrate that fidelity can be estimated from a number of simple experimental settings that is independent of the system size, removing an important roadblock for the experimental study of larger quantum information processing units.Comment: (v1) 11 pages, 1 table, 4 figures. (v2) See also the closely related work: arXiv:1104.4695 (v3) method extended to continuous variable systems (v4) updated to published versio

Private equity challenge – Gelpeixe

Four students collaborated to create this work project, which takes the form of an Investment Committee Paper and proposes the leveraged buyout of Gelpeixe, a frozen food firm based in Portugal. An effective value creation plan supported by the best capital structure was devised, following a thorough examination of the business and the industry, returning an IRR of 25.5% and a Money Multiple of 3.0x over the course of five years. Additionally, individual contributions were included, delving into the topics of deal financing in private equity, frozen food in private equity, mezzanine financing and the impact of interest rates in private equity