-
26 April, 15.15, in Lundmarksalen
Ruth Pöttgen (Dept of Physics)
Looking at the invisible — Searching for Dark Matter Production at the LHC
-
1 March, 15.00, Vattenhallen
Anna S. Arnadottir
Planetarium show, "Phantom of the Universe - The hunt for Dark Matter"
Program:
15:00 We will gather in the foyer of the astronomy building for some
refreshments.
15:15 We head over to Vattenhallen together.
15:20 Assuming there are more of us than the planetarium can hold, we will split the group. While the first group enjoys the spectacular planetarium show, the second group gets to explore Vattenhallen.
15:55 The second group goes to the planetarium while the first can explore Vattenhallen.
16:30 End of program.
-
30 November 2016, 15.15, in Lundmarksalen
Johan Nilsson
Using "Deep Learning" to analyse interactions between donor and recipient DNA that determine early and late heart transplant failure
Abstract:
The major types of pathological rejection after heart transplantation are acute cellular rejection (ACR) and anti-body-mediated rejection (AMR). Despite the known risk factors for ACR, it is not possible to predict which patients who will develop ACR and at what time point after transplant.
The immune response to an allograft is an ongoing dialogue between the innate and adaptive immune system. Cells of the innate immune system express invariant pathogen associated pattern recognition receptors that enable them to detect not only repeating structural units expressed by pathogens but also markers of tissue injury or damage associated molecular patterns, which results in up-regulating transcription of genes, and production of micro-RNAs. The use of next-generation sequencing (NGS) technologies for whole-genome analysis may provide further knowledge of human leukocyte antigen (HLA) genes or other regions of the genome which are related to the regulation of the immune response. Variation in the sequence of DNA between transplant recipients and their donor may be an explanation for the differences in the chances of progression transplant failure.
The development of methods such as deep learning for analysing the whole genome sequencing that can be brought into the clinical setting and be used as an instrument for better matching of donor organs to recipients could increase short and long-term survival. Furthermore, the immunosuppression may be personalised depending on the patient’s risk of rejection based on the genomic profile.
-
2 November 2016, 15.15, in Lundmarksalen
Hugo Serodio
The flavor puzzle and symmetries: tips for a successful marriage
Abstract:
The mixing and mass patterns of fermions in the Standard Model is
a long standing problem known
as the flavor puzzle. One natural way to describe patterns in nature
is through the help of symmetries.
In the first part of this talk I will review some useful techniques
(or tricks) that can be used
when looking for such patterns. In the second part, I will be more
concrete and present an extension
of the Standard Model where several of the flavor issues are tackled
and interesting predictions for LHC phenomenology are found.
-
14 September 2016, 15.15, in Lundmarksalen
Lennart Lindegren
The first release of astrometric and photometric data from ESA's Gaia mission
Abstract:
The Gaia satellite was launched by the European Space Agency in December 2013. Its goal is to map the positions, distances, motions, brightnesses, and colours of about one billion stars in the Milky Way Galaxy, as well as other point-like sources such as asteroids and distant quasars. The first results of the mission are released today, September 14, in the Gaia Archive. This Gaia Data Release 1 only uses the first 14 months of observations, out of the expected 60 to 120 months before the end of mission, and is therefore very preliminary and incomplete. In the talk I will briefly recall what Gaia is and describe how the data were derived, with some focus on activities where Lund is strongly involved. Examples of important new scientific results will be given.
-
4 May 2016, 15.15, in Lundmarksalen
Victor Olariu
Computational models for cell reprogramming
Abstract:
Embryonic stem cells (ESC) have the capacity to self-renew and remain pluripotent, while continuously providing a source of a variety of differentiated cell types. Understanding what governs these properties at the molecular level is crucial for stem cell biology and its application to regenerative medicine. Of particular relevance is to elucidate those molecular interactions, which govern the reprogramming of somatic cells back into stem cells. A few central transcription factors inside embryonic stem cells and reprogrammed stem cells (induced pluripotent stem (iPS) cells) are believed to control the cells' pluripotency. Characterizations of pluripotent state were put forward on both transcription factor and epigenetic levels. Whereas core players have been identified, it is desirable to map out gene regulatory networks, which govern the reprogramming of somatic cells as well as the early developmental decisions.
A computational approach can be used as a framework to explore the dynamics of a simplified network of the pluripotent cells with the aim to understand how stem cells differentiate and also how they can be reprogrammed from somatic cells. In this talk, I present computational models for core stem cell gene regulatory network, which shed light on regulatory mechanisms governing pluripotency acquisition through reprogramming.
-
6 April 2016, 15.15, in Lundmarksalen
Caterina Doglioni (Dept of Physics)
Searches for dark matter mediators with DARKJETS,
or: how to make the most of LHC data
-
2 March 2016, 15.15, in Lundmarksalen
Piero Ranalli
Astrometric detection of exoplanets with Gaia
Abstract:
Most of the ~2000 exoplanets known today have been discovered by
observing radial velocity motions and/or transits. The astrometric
shifts of stars due to planetary orbits have been detected so far only
in very few cases, despite a long history of interest and claims.
The Gaia satellite, launched in December 2013 and currently gathering
data, measures stellar astrometry with unprecedented precision. It is
estimated that ~20,000 planets will be detected at the end of its
5-year mission.
In this talk, I will review the basic concepts of exoplanet orbit
determination, focusing on the astrometric method. I will explore
Bayesian methods for fitting the orbital parameters of exoplanets, and
assess their efficiency using simulated Gaia observations. I will
introduce information-based criteria to determine the ranking of
different models (star without planet, single planet with circular
orbit, single planet with eccentric orbit, ...). Finally I will
compare the Bayesian approach with the traditional one, which is based
on least-squares fitting and on the likelihood-ratio test.
-
11 November 2015, 15.15, in Lundmarksalen
Tomas Martin-Bertelsen
Mapping fungal genes to decomposition of soil organic matter
Abstract:
Globally, more carbon (C) is stored in soil organic matter (SOM) than is present in the terrestrial biomass and the atmosphere combined. Whether soils will capture, store or release carbon will be critical for regulating the atmospheric carbon dioxide level and thus the Earth's climate. The molecular interactions between SOM, microorganisms and the physicochemical environment are not well understood thus limits our ability to predict how SOM will respond to environmental changes. Plant-litter (dead leaves, roots) is the main input source to SOM and litter-decomposing fungi play an important role in the degradation of SOM. Within the multidisciplinary MICCS research program (www.miccs.info) we aim to characterize the enzyme pathways that mediate SOM decomposition. Wetlab experimentalists produce high-dimensional transcriptomic (gene expression) and spectroscopic (chemical modifications) data. In this talk I will describe the computational approaches we are adapting for discovery of links between genes and the mediated chemical modifications of SOM extracts.
-
9 September 2015, 15.15, in Lundmarksalen
Alexander Mustill
Dynamic exoplanets
Abstract:
Planetary systems change: over long time-scales planets perturb each
others' orbits away from perfect Keplerian motion. Planets can
experience both regular orbital variations and more violent
instabilities that can lead to collisions between planets or their
ejection from their system. In this talk I will describe the diversity
of dynamical behaviour that planetary systems can exhibit, and explain
why a knowledge of their orbital dynamics is necessary for a full
understanding of the planets themselves.
-
13 May 2015, 15.15, in Lundmarksalen
Ilkka Helenius
Parton distribution functions and Monte Carlo simulations of photon-photon collisions
Abstract:
When colliding hadrons at high energies, e.g. protons at the LHC, the interactions happen between the quarks and gluons which are the constituents of the hadrons. The distribution of these partons inside the hadron cannot be computed from the first principles of QCD but can be determined using experimental data as an input. In the first part of the talk I will introduce the theoretical framework that is used in the parton distribution function (PDF) analyses and briefly discuss about the experimental data that are included in the analyses. I will also describe how the PDFs are modified in nuclear collisions. In the second part I will discuss why one should consider also the partonic structure of photons and show some preliminary results from our Monte Carlo simulations of photon-photon collisions with PYTHIA8 event generator.
-
15 April 2015, 15.15, in Lundmarksalen
Bertram Bitsch
Evolution of protoplanetary discs and why it is important for planet formation
Abstract:
The birthplace of planets around newly born stars is the protoplanetary disc surrounding the star. In these discs dust particles can collide, grow and form ever bigger objects, the so-called planetesimals, which form by dust particles collapsing due to gravity. These planetesimals can then collide and form even bigger objects, the cores of giant planets, which can attract gas from the protoplanetary disc and become gas giants like Jupiter. The movement and growth of dust and the formation planetesimals depends on the structure of the protoplanetary discs. In this talk I will discuss the influence of the structure and evolution of protoplanetary discs on the formation of planetesimals and planets.
-
25 February 2015, 15.15, in Lundmarksalen
Patrik Edén
When the hay looks like needles — statistical challenges in omics data mining
Abstract:
Standard statistical methods, preferably involving test sets, can control false discovery rates in the enormously flexible microarray data analysis. However, it is normally assumed that a similar flexibility in pre-processing (e.g. quality control and noise filter) was not exploited with knowledge of sample properties. This leaves the typical research group with the unpleasent choice to either abstain from pre-processing optimization or lose formal control of their statistical tests. I will discuss a possible solution and present preliminary results.
-
7 May 2014, 15.15, in Lundmarksalen
Lia Athanassoula
Formation of galactic bars and bulges
Abstract:
Like many other disc galaxies, the Milky Way has a bar and a boxy
bulge in its central parts. I will use N-body simulations to discuss
the formation, evolution and properties of such structures, with
emphasis in our Milky Way bar/bulge region. I will also discuss the
role of the dark matter and of gas in these processes,
and how baryonic and dark matter interact.
-
5 March 2014, 15.15, in Lundmarksalen
Gösta Gustafson
How
can we understand the strong force?
-
5 February 2014, 15.15, in Lundmarksalen
Mattias Ohlsson
Modeling
of survival data and some nice applications in clinical
medicine
-
13 November 2013, 15.15, in sal F (K404)
Ross Church
Cosmic
explosions from compact binaries
Abstract:
The majority of observed high-energy transient astrophysical events are
associated with massive stars, and these massive stars are in the most part
in binaries: gravitationally bound systems in which two stars orbit their
common centre of mass. Interactions between the two stars can profoundly
change their evolution and lead directly to explosive events such as
gamma-ray bursts. I will briefly review the evolution of single and binary
stars and discuss three examples of binary interactions leading to
high-energy transients: long-duration gamma-ray bursts from black-hole
binaries, short-duration gamma-ray bursts from neutron star-binaries and
calcium-rich explosions from white-dwarf--neutron-star binaries.
-
23 October 2013, 15.15, in sal F (K404)
Anders Irbäck
Modeling
protein aggregation - from sticks to atomic representation
-
2 October 2013, 15.15, in sal F (K404)
Subir Sarkar (Niels Bohr Institute and University of Oxford)
Connecting Inner Space & Outer Space
Abstract:
We have just celebrated the centenary of the finding that
the Earth is constantly bombarded by high energy `cosmic rays'
from outer space. This initiated a glorious era of discovery
of many new elementary particles (positron, muon, pion, ...) and
developed into accelerator-based research in high energy physics.
A century later this has given us the triumphant `Standard Model'
of particle physics which provides a precise quantum description
of all fundamental processes in terrestrial laboratories,
including (with the recent discovery of "a Higgs boson")
an understanding of how particles acquire mass.
Unfortunately the Standard Model does not explain any of the
salient features of the universe as a whole - Why there is matter
but no antimatter? Why there is so much more `dark matter'
of unknown origin? Why is the expansion rate apparently
accelerating, as if driven by a Cosmological Constant-like,
dominant component of `dark energy'? I will describe how new
experiments and theoretical developments at the rapidly growing
interface of astro-particle physics are attempting to answer
these cosmic questions, by linking them to possible new physics
beyond the Standard Model.
-
10 April 2013, 15.15, in Lundmarksalen
Malin Sjödahl
The
three colours of the strong force
-
6 March 2013, 15.15, in sal F
Chao-Chin Yang
Turbulent
Mixing in Galactic Disks
Abstract:
Observations show that radial metallicity gradients in disk galaxies
are relatively shallow, if not flat, especially at large galactocentric
distances and for galaxies in the high-redshift universe. Given that
star formation and metal production are centrally concentrated, this
requires a mechanism to redistribute metals. However, the nature of
this mechanism is poorly understood, let alone quantified. I will
present my first-principle calculations of turbulent mixing driven
by thermal instability, and argue that this is an efficient process
in redistributing metals on large scales. And then I will discuss
the on-going extension of this work to understand the chemical
homogeneity in old star clusters.
-
6 February 2013, 15.15, in Lundmarksalen
Bo Söderberg
Quasiperiodic
Patterns in Biology
Abstract:
There has been some interest lately in certain mechanisms for pattern
formation in biological tissue, where the dynamics is based not only on
diffusion and local production/deletion, as in conventional reaction-
diffusion models, but also on so called active transport.
Some of the related equations bear relations to Newton's and
Schrödinger's equations, and the dynamics sometimes allow for
quasiperiodic patterns due to the existence of a non-trivial
spatial conservation law.
-
14 November 2012, 15.15, in Lundmarksalen
Greg Ruchti
Lithium in the Cosmos
-
17 October 2012, 15.15, in Sal F
Johan Rathsman
The "Higgs" discovery - a portal to new physics
Abstract:
Starting from the experimental discovery of a Higgs-like particle,
I will recapitulate the role of the Higgs boson in the standard model
of particle physics. Then I move on to discuss the implications of
the discovery, and how the detailed properties of the "Higgs" particle
can tell us something about physics beyond the standard model,
such as supersymmetric theories.
-
19 September 2012, 15.15, in Sal F
Carl Troein
Modelling the plant circadian clock
Abstract:
The vast majority of living organisms are exposed to daily cycles
in temperature, sunlight and other environmental factors. The ability
to anticipate these rhythmic changes is highly beneficial: clocks with
a 24-hour period are found in many different lifeforms, including both
animals and plants.
In the plant model organism Arabidopsis thaliana, more than a
dozen genes form the core of the clock. Together they form a complex
network of interactions, with positive and negative feedbacks and many
inputs and outputs. Over the past decade, more and more complete
models clock have been created, typically in the form of ordinary
differential equations, based on a vast number of experiments.
In this talk, I will present the biological background and
building blocks of circadian clocks, and show how the models have been
- and, despite their complexity, are still being - iteratively
improved through feedback between modelling and experimentation.
-
24 May 2012, 10.00, at the Ecology House
Honorary Doctor's Seminar by Bryan Webber
Improving the precision of high-energy simulation
and analysis tools
-
18 April 2012, 15.15, in Lundmarksalen
Melvyn Davies
Stellar Clusters: Factories Producing Exotic Objects
-
14 March 2012, 15.15, in Lundmarksalen
Torbjörn Sjöstrand
Status of the LHC and Anatomy of LHC Events
-
22 February 2012, 15.15, in sal F, theoretical physics
Dimitri Argyriou (Director of Science, ESS)
The European Spallation Source: What is it and what
can I do with it !
Abstract:
In this talk I will discuss briefly what is the European Spallation
Source and why it is different from other sources. Apart from
highlighting how neutrons are used in science today, the talk will
also focus on some of the special opportunities that ESS offers.
-
25 January 2012, 15.15, in sal F, theoretical physics
Erik Lindahl (KTH)
Simulation of Structure & Function of Biological
Macromolecules
Abstract:
Biological macromolecules are fascinating machines with highly
complex functional roles determined by their structure, but this
in turn is determined by fairly simple physical interactions. In
principle it is possible to simulate the folding of e.g. a protein
in a computer, but the very high computational complexity has
limited this to small systems even when using special-purpose
hardware. I will discuss how we are trying to address this problem
by using different approaches to computation that originally
came out of our work on the Folding@Home project, and how it
might be possible to model quite complex and general biological
processes with large numbers of simulations running as an ensemble
on extremely large future "exascale" computers, in particular
by using Markov State Models. I will also present how we are
applying these techniques to model functions and drug interactions
for ligand-gated ion channel membrane proteins to illustrate
how current simulations provide concrete functional conclusions
for proteins that complement and guide other experimental methods.
-
7 December 2011, 15.15, at Lundmarksalen
Thomas Bensby
The chemical history of the Galactic bulge and disk
-
16 November 2011, 15.15, at Lundmarksalen
Roman Pasechnik
The Physical Vacuum: Where Particle Physics Meets
Cosmology
Abstract:
The Nobel Prize in Physics this year has been awarded "for the
discovery of the accelerating expansion of the Universe through
observations of distant supernovae". Such a fundamental discovery
together with up-to-date results from the Large Hadron Collider
poses even more fundamental questions to our understanding of the
structure of the Physical Vacuum, both at micro and macro scales.
Many diverse unsolved problems ranging from e.g. the Supersymmetry
breaking mechanism giving a natural candidate for the Dark Matter,
the Higgs issue in the Standard Model and the confinement issue in
the Quantum Chromodynamics up to the Dark Energy issue leading to
observable acceleration of the Universe originate from poorly
understood structure of the Physical Vacuum. In this talk, I make an
attempt to review this very complicated problem from different
perspectives, as well as to go through major current and possible
theoretical developments at frontiers of Particle Physics and
Cosmology.
-
2 November 2011, 15.00 (note time!), at Lundmarksalen
Stefan Wallin
Monte Carlo simulation of proteins: from folding to
"nonfolding" to interactions
-
4 May 2011, 15.15, in sal F, theoretical physics
Sven-Erik Strand and Freddy Ståhlberg
Imaging possibilities at Lund University BioImaging Center
-
2 February 2011, 15.15, at Lundmarksalen
Gösta Gustafson
The physics of musical instruments
Abstract:
Why does a clarinet sound one octave lower than an oboe or a saxophone
of the same length, and why is the first overtone missing in the clarinet?
Why should you not hit a drum in the center?
What is the motion of a violin string?
Why can you have finger holes in a flute but not in a trumpet?
These are some of the questions to be discussed in the talk.
-
8 December 2010, 15.15, at sal F
Henrik Jönsson
The art of moving when you are stuck - from Darwins'
research on plants to state of the art methods for resolving the
underlying mechanisms of multicellular life
Abstract:
The differentiation of stem cells into different cell types and the
possibility of guiding cells back to stem cells are currently
attracting much attention within developmental biology and medical
research. Plants, unable to move around, rely on an ability to respond
to the environment and continue the production of organs throughout
their lives. Hence they have developed the competence to regulate stem
cells and growth depending on intrinsic and external signals. I will
discuss our research on combining mathematical models and live imaging
techniques to gain insights in the mechanisms regulating multicellular
development. I will show that a combination of gene regulation,
hormone signaling, and mechanical stresses are important for
development.
-
17 November 2010, 15.15, at Lundmarksalen
Anders Johansen
How migrating geese and falling pens inspire
planet formation
Abstract:
Planets form in gaseous discs around young stars as tiny dust grains collide to
form larger and larger bodies. This paradigm however faces major problems as
particles reach cm sizes, as macroscopic bodies are more prone to bouncing and
shattering than to sticking. I will talk about my computational work on
explaining the formation of km-sized planetesimals from cm-sized pebbles.
Particles fall at their terminal velocity towards the point of highest
pressure, like objects on earth falling to the floor. High-pressure regions in
circumstellar discs collect particles this way. An aerodynamical streaming
instability causes particles to clump further, analogous to how migrating geese
and bicycle riders travel in groups to reduce their common air resistance. The
local particle density can become high enough to initiate a gravitational
collapse of the pebble component. This planet formation picture has widespread
implications for observations of exoplanets and for explaining why the solar
system formed when it did.
-
3 November 2010, 15.15, at sal F
Joakim Edsjö (Stockholm University)
Dark matter searches in the sky and underground
Abstract:
Finding the dark matter in the Universe is one of the big questions in
science today. I will here go through various ways to search for dark
matter and discuss the current status both from a particle physics and
astrophysics point of view. I will also discuss future searches that
will take place in the near future.
-
20 October 2010, 15.15, at Lundmarksalen
Sofia Feltzing
Near field cosmology, now and in the Gaia era
Abstract:
I will review the current status of the field often
referred to as near field cosmology, i.e. the study of cosmologically
interesting process but in the local volume. In particular I will
focus on our understanding of the Milky Way as a galaxy and how it
constrains the cosmological models. The advent of Gaia will radically
change the impact of near field cosmology on cosmology in general.
-
9 June 2010, 15.15 at sal F
Zoran Konkoli (Department of Microtechnology and Nanoscience - MC2,
Chalmers University of Technology, Sweden)
Computational modeling of the living cell biochemistry:
What statistical physicists are not but should do
Abstract:
The talk will discuss how Statistical Physics tools
can be used to understand biochemistry of the living cell. Structures
found in the living cell are rather special and to achieve such task
tchniques used in the field of Statistical Physics need to be slightly
modified. A critical reflection is needed on which techniques to use and
for what purpose. As an example the theory of diffusion controlled
reactions will be reviewed with a purpose of using it for understanding
spatio-temporal organization of the living cell.
It will be argued that formalism of diffusion controlled reactions is a
suitable framework for describing living cell and the scope and the
limitations of such approach will be discussed. Informal discussion will
be given around problems (and possible traps) one meets when trying to
compute properties of biochemical reactions in the cell interior. For
example, assumption of perfect mixing is frequently used for modeling.
However, large number of processes in the cell exists to battle precisely
lack of perfect mixing. Few selected issues related to validity of mean
field equations (perfect mixing) in describing intracellular kinetics will
be discussed.
The last part of the talk will cover more applied topics. It will be
shown how framework of diffusion controlled reactions (and Markov chains)
can be used to analyze spatio-temporal organization of the living cell.
A platform for doing such analysis, Geometry-Reaction InterPlay (GRIP),
will be presented. If the time allows some issues related to complex
noise formation will be discussed.
-
26 May 2010, 15.15 at sal F
Dainis Dravins
Boson Interferometry: From astronomy to particle physics,
and back
-
28 April 2010, 14.15 at Lundmarksalen
(double feature, early start!)
Justin Read
Sandipan Mohanty
-
14 April 2010, 15.15 at sal F
Johan Bijnens
Hadrons, Flavours and Effective Theories
-
17 March 2010, 15.15 at Lundmarksalen
Magnus Axelsson
Black holes and cosmic explosions
Abstract:
Stellar mass black holes are the end product of massive stars.
Their formation may be accompanied by spectacular events such as
supernovae and gamma-ray bursts. In this presentation I will
briefly outline this connection and show how observational
results from studies of black holes in binary systems can be used
to probe their formation.
-
3 March 2010, 14.15 at sal F (double lecture, early start!)
Bengt E Y Svensson
ACCELERATED COSMIC EXPANSION: Observations, theoretical ideas
Abstract:
I will review the present understanding of the accelerated expansion
of the universe, the "dark energy" enigma, observationally
discovered about a decade ago and still without a satisfactory explanation.
To try to get everyone on-board, I will start with a "crash
course" in cosmology by presenting all the basics needed (so if you are
unfamiliar with the topic, you will have a cheap chance to get updated!)
After giving a brief summary of the relevant observational data, I will
then dwell on some of the theoretical ideas that have been put forward
to explain the phenomenon.
-
17 February 2010, 15.15 at Lundmarksalen
Tobias Ambjörnsson
The physics of subcellular processes
-
3 February 2010, 15.15 at sal F
Lennart Lindegren
Gaia: A brief overview of the ESA space astrometry project