Parameterized Complexity of Equitable Coloring

A graph on $n$ vertices is equitably $k$-colorable if it is $k$-colorable and every color is used either $\left\lfloor n/k \right\rfloor$ or $\left\lceil n/k \right\rceil$ times. Such a problem appears to be considerably harder than vertex coloring, being $\mathsf{NP\text{-}Complete}$ even for cographs and interval graphs. In this work, we prove that it is $\mathsf{W[1]\text{-}Hard}$ for block graphs and for disjoint union of split graphs when parameterized by the number of colors; and $\mathsf{W[1]\text{-}Hard}$ for $K_{1,4}$-free interval graphs when parameterized by treewidth, number of colors and maximum degree, generalizing a result by Fellows et al. (2014) through a much simpler reduction. Using a previous result due to Dominique de Werra (1985), we establish a dichotomy for the complexity of equitable coloring of chordal graphs based on the size of the largest induced star. Finally, we show that \textsc{equitable coloring} is $\mathsf{FPT}$ when parameterized by the treewidth of the complement graph

Evaluation of group work in the Chemistry and Biotechnology laboratory: Case study

Trabalho apresentado em CISPEE 2018, 27-29 de junho de 2018, Aveiro, PortugalN/

An overview

Human diseases caused by protozoan parasites are renowned for their high rates of morbidity and mortality worldwide. Some examples include African trypanosomiasis or sleeping sickness, American trypanosomiasis or Chagas disease, leishmaniases, malaria and babesiosis. These infections tend to follow a chronic rather than an acute course with lifelong persistence of parasites. Regulatory T cells (Treg), in particular the CD4+CD25+ cell subset, appear to control the immune competence of host response triggered by the presence of parasites, promoting homeostasis and protecting the host from collateral tissue damage whilst allowing parasite persistence. To date, there is still considerable controversy on the characteristics and function of these cells when induced during diferente protozoan infections, evidencing the need of further research. Therefore, this review aims to provide a comprehensive overview about Treg cells development, phenotype determination and general functions. The above pathologies were used as selected examples to discuss the role of Treg cells during protozoan infections. Understanding of the mechanisms that contribute towards homeostasis and the survival of the host, and simultaneously allow the persistence of the pathogen, may yield important insights for new strategies of prophylaxis and therapy .publishersversionpublishe

Inteligência artificial aplicada à predicação do ponto de abate de bovinos confinados.

O objetivo deste trabalho foi criar um software para realizar a predição do ponto de abate de bovinos por meio de características e medidas ultrassonográficas obtidas apenas no início do confinamento

Sequestro de Conexões TCP - Uma Abordagem Contemporânea

O protocolo de rede TCP, parte essencial da Arquitetura TCP/IP usada pela Internet, por décadas é estudado e testado em relação a segurança. Desde 1985 a comunidade científica vem execrando este protocolo e mostrando a facilidade de se quebrar requisitos mínimos de segurança dele. Em 1995, Paul Watson apresenta a comunidade científica a facilidade de se quebrar uma conexão TCP deixando ainda mais evidente que os 10 anos não foram suficientes para melhorar a segurança no protocolo TCP. Em 2005 Christoph Wegener e Wilhelm Dolle apresentam um novo artigo mostrando, novamente, que mais 10 anos não foram suficientes. Este trabalho refaz alguns dos testes feitos por Paul Watson orientado por uma metodologia próxima ao deles porém com Sistemas Operacionais recentes para descobrir se ainda o problema do sequestro TCP se apresenta como uma vulnerabilidade atual apesar de um quarto de século passado deste o início dos testes de segurança que o TCP vem sofrendo no tocante ao tipo de ataque de Sequestro de Conexões

Successful treatment of feline leishmaniosis using an association of allopurinol and N-methyl-glucamine antimoniate

This work describes the diagnosis and successful treatment of a 2-year-old domestic cat infected with Leishmania species and presenting fever, and ulcerative and nodular skin lesions after being treated for pyodermatitis for 1 year without clinical improvement. After anamnesis the cat was submitted to a complete clinical examination. Blood was collected for determination of haematological and biochemical parameters, detection of feline leukaemia virus (FeLV), feline immunodeficiency virus (FIV), feline coronavirus (FCoV) and Leishmania amastigotes. Fine-needle aspiration puncture from the skin nodules was also performed. After definitive diagnosis the animal was treated and followed up over a 2 year period. The animal tested negative for FIV-specific antibodies, FeLV antigen and feline coronavirus RNA. Leishmania amastigotes in the skin nodules were confirmed by cytology and molecular diagnosis. Treatment was initiated with allopurinol, resulting in a slight clinical improvement. Thus, N-methyl-glucamine antimoniate was added and administered for 30 days, with complete closure of the ulcerative lesions in the hindlimbs requiring a surgical approach. Close monitoring of the patient in the following 24 months indicated that combined therapy was safe and clinical cure was achieved without further relapses or side effects.publishersversionpublishe

Genetic disruption of NRF2 promotes the development of necroinflammation and liver fibrosis in a mouse model of HFE-hereditary hemochromatosis

In hereditary hemochromatosis, iron deposition in the liver parenchyma may lead to fibrosis, cirrhosis and hepatocellular carcinoma. Most cases are ascribed to a common mutation in the HFE gene, but the extent of clinical expression is greatly influenced by the combined action of yet unidentified genetic and/or environmental modifying factors. In mice, transcription factor NRF2 is a critical determinant of hepatocyte viability during exposure to acute dietary iron overload. We evaluated if the genetic disruption of Nrf2 would prompt the development of liver damage in Hfe(-/-) mice (an established model of human HFE-hemochromatosis).This work was supported by National funds through Fundação para a Ciência e a Tecnologia/Ministério da Educação e Ciência (PTDC/SAU-FCF/101177/2008, PTDC/BIM-MET/0739/2012 and SFRH/BPD/108207/2015), by FEDER funds through the COMPETE – Operational Competitiveness Programme (FCOMP-01-0124-FEDER-011062 and FCOMP-01-0124-FEDER-028447) and Project Norte-01-0145-FEDER-000012, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER), and by Reitoria da Universidade do Porto/Santander through PP-IJUP2011-122.info:eu-repo/semantics/publishedVersio

Método de Seleção de bactérias antagonistas a Sclerotinia sclerotiorum.

O objetivo deste trabalho foi obter e avaliar o efeito de bactérias isoladas de escleródios como agentes antagônicos no crescimento micelial de S. sclerotiorum