In this issue of the bulletin, we present an article about the topological complexity of surfaces, which is a notion introduced by M. Farber in order to classify the complexity of the motion planning problem in robotics.
We also include a paper regarding the representation of commutative rings and respective modules by means of the prime spectrum, which is the set of prime ideals of a ring. We present an article about small tubular neighbourhoods of the n-twisted Möbius strip described as affine varieties associated to explicit polynomials in three real variables, exhibiting illustrations produced with the software surfer.

In a joint initiative of the Centro Internacional de Matemática (CIM) and the Instituto de Ciencias Matemáticas (ICMAT) a simbolic mathematical celebration of the Periodic Table took place at the Academy of Sciences of Lisbon, the 21st November 2019.

The workshop Nonlinear PDEs in Braga was a joint organization of the following Portuguese research centers of mathematics: CMAT (University of Minho), CMAFcIO (University of Lisbon) and CMUC (University of Coimbra), and also counted with the support of CIM and FACC-FCT.

Graciano Neves de Oliveira was born on the 7th of May 1938, in Cabanas de Viriato, Portugal. He graduated in Mathematics at the University of Coimbra in 1961, and in 1969 he obtained his doctorate at the University of Coimbra with the thesis On Stochastic and Double Stochastic Matrices. Due to his political ideas, he had problems in keeping a job at Portuguese universities, until in 1976 he became a professor at the University of Coimbra. He retired from this university in 2002.

Graciano de Oliveira’s main research work is in matrix theory and multilinear algebra, an area in which he published extensively and produced several seminal articles. He supervised 11 Ph. D. students and was the leader of the Coimbra school of matrix theory.

Graciano de Oliveira was President of the Portuguese Mathematical Society from 1986 to 1988 and from 1996 to 2000, and Vice-President of the International Linear Algebra Society from 1993 to 1995. He also served on the Editorial Boards of Linear Algebra and its Applications and Portugaliae Mathematica.

The notion of topological complexity of a space has been introduced by M. Farber in order to give a topological measure of the complexity of the motion planning problem in robotics. Given a mechanical system, this problem consists of constructing an algorithm telling how to move from any initial state to any final state. In this note, after some generalities about this invariant, we will survey the determination of the topological complexity when $X$ is a (connected closed) surface.

The LxDS-Lisbon Dynamical Systems Group, the Department of Mathematics at FCUL, CEMAPRE, REM and CMAF-CIO organized a spring school on the days 29-31 of May 2019 in dynamical systems, which took place at the Faculty of Sciences of the University of Lisbon (FCUL).

Luis Woodhouse was born on the 31st of July of 1857 into an important family of Porto society at that time, and he lived in a period of great political instability in Portugal. In 1910, the old monarchy was overthrown and the Portu- guese republic was established. This new regime led to ma- jor changes in the higher education system. The Polytechnic Academy of Porto, created in 1836, gave rise to the University of Porto, formally founded on the 22nd of March of 1911, and initially structured in two schools, the Faculty of Sciences and the Faculty of Medicine. Woodhouse graduated in 1881 from the University of Coimbra, which was the only university in the country, at the time. He brilliantly completed the five years of the Mathematics degree, during which time he was distinguished with several awards in different subjects.

The International meeting Particle Systems and Partial Differential Equations VIII took place at Instituto Superior Técnico, University of Lisbon, from the 2nd to the 6th December 2019.
This was the eighth edition of the meeting, after five editions at the University of Minho, from 2012 to 2016, one edition at the University of Nice Sophia Antipolis, France, in 2017, and another one at the University of Palermo, Italy, in 2018.

Given a commutative noetherian ring R we discuss its representations, i.e. its R-modules. The prime spectrum of R plays a fundamental role, controlling much of the structure of the category of R-modules. We illustrate this in two instances, surveying a parametrisation of localising subcategories and a parametrisation of flat ring epimorphisms.

Global Portuguese Mathematicians is a biennial conference series bringing together Portuguese mathematicians working worldwide. It aims to disseminate high-level research, promoting new collaborations as well as connecting the Portuguese-speaking mathematical community.

We construct explicit polynomials p_n in three real variables x, y and z such that the associated affine variety p_n^{-1}(0) gives a small tubular neighborhood of the n-twisted Möbius strips. The degree of p_n is given by 4+2n. We give visualizations up to twisting number n = 6 using the free software surfer of the open source platform Imaginary.

From July 15 to 17, 2019, ECAS2019 on Statistical Analysis for Space-Time Data was held at the Faculty of Science of the University of Lisbon, organized by the Portuguese Statistical Society (SPE) and the Spanish Society of Statistics and Operational Research (SEIO).

The international conference on Algebraic Analysis and Geometry with a view on Higgs bundles and D-modules took place last June, from 3 to 7, at the Mathematics Department of the Sciences Faculty of the University of Porto.

To celebrate the 2018 European Year of Cultural Heritage, the Lisbon Academy of Sciences hosted on 19 December 2018 the Colloquium on Mathematics and Cultural Heritage. This was an initiative of the International Center for Mathematics (CIM) and the Portuguese Society of Mathematics (SPM), under the program of the Planet Earth Mathematics Committee, which has the support of the National Commission of UNESCO Portugal. The program was also supported by the University of Coimbra Science Museum (MCUC) and the University
of Lisbon National Museum of Natural History and Science (MUHNAC).

Martin Hairer is a British-Austrian mathematician working in the field of stochastic analysis, who was awarded a Fields medal in 2014, the most prestigious prize in the career of a mathematician. He holds a chair in  Probability and Stochastic Analysis at Imperial College London and is considered to be one of the world’s foremost leaders in the field of stochastic partial di!erential equations (SPDEs) in particular, and in stochastic analysis and stochastic dynamics, in general. By bringing new ideas to the subject he made fundamental advances in many important directions such as the study of variants of Hörmander’s theorem, the systematization of the construction of Lyapunov functions for stochastic systems, the development of a general theory of ergodicity for non-Markovian systems, multiscale analysis techniques, the theory of homogenization, the theory of path sampling and, most recently, the theory of rough paths and the newly introduced theory of regularity structures. Besides the Fields medal, he was awarded several highly reputed prizes and distinguished with several honors and distinctions. Among those, we mention the LMS Whitehead prize, the Philip Leverhulme Prize, the Fermat prize, the Fröhlich prize. He was distinguished as a fellow of the Royal Society, the American Mathematical Society, the Austrian Academy of Sciences, the Berlin-Brandenburg Academy of Sciences and Humanities, the German National Academy of Sciences Leopoldina and was also distinguished as an Honorary Knight Commander of the British Empire. He was awarded several fellowships and grants including an ERC, a Leverhulme Leadership Award, EPSRC; he is editor of several leading journals and delivered talks in many highly reputed institutions worldwide.