Calendar

For information about attending a Salisbury Cafe Scientifique event, see the Attending an Event section; there is also more general information in the Frequently Asked Questions section and help on making the most of this calendar in the Calendar Help section. If you fancy a night of science outside but close to Salisbury, there is also this filtered list of nearby events.

Sep
16
Mon
2019
Towards the design of molecular materials – Dr Gerit Brandenburg, Heidelberg University and UCL
Sep 16 @ 2:15 pm – 3:15 pm

New technologies are made possible by new materials, and until recently new materials could only be discovered experimentally. However, approaches based on the fundamental laws of quantum mechanics are now integrated to many design initiatives in academia and industry, underpinning efforts such as the Materials Genome initiative or the computational crystal structure prediction (CSP [1]). The latest CSP blind test organized by the Cambridge Crystallographic Data Center [2] revealed two major remaining challenges:
(i) Dealing with a vast search space, in particular for molecules with increased flexibility one has to sample about 1 Mio possible crystal structures.
(ii) Crystal polymorphs are often separated by just a few kJ/mol, exceeding the accuracy of standard density functional approximations (DFAs).
Cost-effective electronic structure methods will be presented that gain up to four orders of magnitude in computational speed compared to traditional DFAs and are suited for optimizing a huge number of putative crystal structures [3]. Promising applications to the CSP of pharmaceutical-like molecules have been demonstrated recently [4]. On the other hand, recent algorithmic developments in Quantum Monte-Carlo make it feasible to molecular crystals and we are now able to predict static lattice energies with potentially sub-chemical accuracy [5]. A perspective on employing machine learning techniques in the CSP context will be discussed.

[1] S. L. Price, JGB, Molecular Crystal Structure Prediction; Elsevier Australia, 2017.
[2] A. M. Reilly, R. I. Cooper, C. S. Adjiman, S. Bhattacharya, A. D. Boese, JGB, P. J. Bygrave, R. Bylsma, J.
E. Campbell, R. Car, et al. Acta. Cryst. B 2016, 72, 439.
[3] E. Caldeweyher, JGB, J. Phys.: Condens. Matter 2018, 30, 213001.
[4] L. Iuzzolino, P. McCabe, S. L. Price, JGB, Faraday Discuss. 2018, 211, 275.
[5] A. Zen, JGB, J. Klimeš, A. Tkatchenko, D. Alfè, A. Michaelides, Proc. Natl. Acad. Sci. USA 2018, 115, 1724.

Sep
18
Wed
2019
Neural mechanisms of proprioception and motor control in Drosophila – John Tuthill, Department of Physiology and Biophysics, University of Washington @ MRC LMB: Klug Seminar Room 2A180
Sep 18 @ 10:00 am – 11:00 am
Constructing Discontinuous Galerkin methods for Vlasov-type systems – Blanca Ayuso De Dios (Università degli Studi di Milano – Bicocca; Istituto di Matematica Applicata e Tecnologie Informatiche (IMATI))
Sep 18 @ 2:05 pm – 2:50 pm

The Vlasov-Poisson and the Vlasov-Maxwell systems are two classical models in collisionless kinetic theory. They are both derived as mean-field limit description of a large ensemble of interacting particles by  electrostatic and electro-magnetic forces, respectively.
In this talk we describe how to design (semi-discrete!) discontinuous Galerkin finite element methods for approximating such Vlasov-type systems. We outline the error analysis of the schemes and discuss further properties of the proposed schemes, as well as their shortcomings.
If time allows, we discuss further endeavours in alleviating the drawbacks of the schemes. 

Constructing Discontinuous Galerkin methods for Vlasov-type systems – Blanca Ayuso De Dios (Università degli Studi di Milano – Bicocca; Istituto di Matematica Applicata e Tecnologie Informatiche (IMATI))
Sep 18 @ 2:05 pm – 2:50 pm

The Vlasov-Poisson and the Vlasov-Maxwell systems are two classical models in collisionless kinetic theory. They are both derived as mean-field limit description of a large ensemble of interacting particles by  electrostatic and electro-magnetic forces, respectively.
In this talk we describe how to design (semi-discrete!) discontinuous Galerkin finite element methods for approximating such Vlasov-type systems. We outline the error analysis of the schemes and discuss further properties of the proposed schemes, as well as their shortcomings.
If time allows, we discuss further endeavours in alleviating the drawbacks of the schemes. 

Variational systems on the variational bicomplex – Linyu Peng (Waseda University)
Sep 18 @ 3:05 pm – 3:50 pm

 It is well know that symplecticity plays a fundamentally important role in Lagrangian and Hamiltonian systems. Numerical methods preserving symplecticity (or multisymplecticity for PDEs) have been greatly developed and applied during last decades.  In this talk, we will show how the variational bicomplex, a double cochain complex on jet manifolds, provides a natural framework for understanding multisymplectic systems. The discrete counterpart, discrete multisymplectic systems on the difference variational bicomplex will briefly be introduced if time permits.

Variational systems on the variational bicomplex – Linyu Peng (Waseda University)
Sep 18 @ 3:05 pm – 3:50 pm

 It is well know that symplecticity plays a fundamentally important role in Lagrangian and Hamiltonian systems. Numerical methods preserving symplecticity (or multisymplecticity for PDEs) have been greatly developed and applied during last decades.  In this talk, we will show how the variational bicomplex, a double cochain complex on jet manifolds, provides a natural framework for understanding multisymplectic systems. The discrete counterpart, discrete multisymplectic systems on the difference variational bicomplex will briefly be introduced if time permits.

Sep
19
Thu
2019
Energy preserving spectral methods on the real line whose analysis strays into the complex plane (copy) – Marcus Webb (University of Manchester)
Sep 19 @ 4:00 pm – 5:00 pm
Energy preserving spectral methods on the real line whose analysis strays into the complex plane (copy) – Marcus Webb (University of Manchester)
Sep 19 @ 4:00 pm – 5:00 pm
Energy preserving spectral methods on the real line whose analysis strays into the complex plane – Marcus Webb (University of Manchester)
Sep 19 @ 4:00 pm – 5:00 pm
Energy preserving spectral methods on the real line whose analysis strays into the complex plane – Marcus Webb (University of Manchester)
Sep 19 @ 4:00 pm – 5:00 pm
Sep
23
Mon
2019
Anisotropic Dipolar Interactions in Indirect Exciton Bilayers – Paulo V. Santos,
Sep 23 @ 11:00 am – 12:00 pm

The dipolar interaction normally dominates the coupling between charge neutral species with a
dipolar moment. Contrary to the isotropic Coulomb interaction, the dipolar coupling depends not
only on the separation r between the dipoles but also on the angle θ between r and the dipole
moment p. In particular, for collinear dipoles, the dipolar coupling turns from repulsive for large θ to
attractive for cos 2 θ < 1/3. This anisotropic character gives rise to interesting phenomena in dipolar
systems including pattern formation and instabilities in ferrofluids, liquid crystals, and Bose-Einstein
condensates of dipolar species.[2]
In this talk, we demonstrate that the attractive component of the dipolar interaction can bind
aligned solid-state dipoles consisting of indirect excitons (IX) in two stacked double quantum well
bilayers.[1] Each bilayer consists of two QWs separated by a thin tunneling barrier. A vertical electric
field applied across the structure drives electrons and holes to different QWs, thus producing IX with
a dipole moment aligned with the field. By using spatially and time-resolved photoluminescence
spectroscopy, we show that the presence of a dipolar cloud in one bilayer changes the spatial
distribution of IX dipoles in the other bilayer. The changes in spatial distribution are accompanied by
an increase in the IX binding energy, which are accounted for by a polaron model for the IX-IX
interaction. These results demonstrate the feasibility of dipolar control gates using stacked
structures and open the way for the realization of interacting dipolar lattices in semiconductor
systems.
This project has received funding from the German DFG and the German-Israeli Foundation (GIF).
*santos@pdi-berlin.de
References
[1] Colin Hubert, Yifat Baruchi, Yotam Mazuz-Harpaz, Kobi Cohen, Klaus Biermann, Mikhail
Lemeshko, Ken West, Loren Pfeiffer, Ronen Rapaport, and Paulo Santos. Attractive dipolar coupling
between stacked exciton fluids. Phys. Rev. X, 9:021026, May 2019.
[2] T Lahaye, C Menotti, L Santos, M Lewenstein, and T Pfau. The physics of dipolar bosonic quantum
gases. Rep. Prog. Phys., 72(12):126401, 2009.

Sep
24
Tue
2019
Advanced polarized light microscopy for mapping molecular orientation – Prof Rudolf Oldenbourg, Marine Biological Laboratory, MA
Sep 24 @ 9:30 am – 11:00 am

Polarization is a basic property of light, but the human eye is not sensitive to it. Therefore, we don’t have an intuitive understanding of polarization-dependent phenomena. However, polarized light plays an important role in nature, and polarization microscopy can be used to understand molecular order in living cells, tissues, and whole organisms. The talk will describe a polarized light microscope, developed at the Marine Biological Laboratory (MBL) in Massachusetts, called the LC-PolScope. This instrument measures the orientation of molecules at every resolved specimen point simultaneously. In addition to birefringence and diattenuation, it can also map the polarized fluorescence of fluorophores used to label structures like cell membranes and filaments. Recently, these techniques have been extended to multi-view microscopes. With a single-view microscope, measuring the inclination angles of the optical axes of bonds, particles, and fluorophores with respect to the focal plane remains a challenge. Multi-view microscopes record images along several viewing directions, thereby enabling unambiguous measurement of the three-dimensional orientation of molecules and their aggregates

Conversion between singlet and triplet states in the strong and weak coupling regimes. – Karl Börjesson; University of Gothenburg
Sep 24 @ 2:00 pm – 3:30 pm

Chemists can today synthesize virtually any molecule imaginable. By fine tuning the molecular structure, optimized physical, chemical, or biological properties are routinely achieved. However, even though molecular optimization has reshaped the world we live in, there is always a point at which the laws of physics limits the performance of molecular systems. Tailoring of molecular properties can be achieved through strong coupling between molecular states and the zero-point fluctuations of the electromagnetic field (vacuum field) [1]. The formed hybrid states (exciton polaritons) have unique chemical and physical properties and can be viewed as a linear combination of light (vacuum field) and matter (molecules). I will present how the energy difference between singlet and triplet energy levels can be reduced by strong light matter interactions, allowing for a higher rate of reversed intersystem crossing [2]. I will further describe how resonance energy transfer can be used for multiplicity conversion in the weak coupling regime [3]. The last part of my talk will be on triplet-triplet annihilation photon upconversion, focusing on excimer formation on the triplet surface, which is a previously overlooked process in the community [4].

[1] Hertzog, Wang, Mony and Börjesson, Chem. Soc. Rev., 2019, 48, 937-961.
[2] Stranius, Hertzog and Börjesson, Nat. Commun., 2018, 9:2273.
[3] Cravcenco, Hertzog, Ye, Iqbal, Mueller, Eriksson and Börjesson, Sci. Adv. 2019, accepted
[4] Ye, Gray, Mårtensson and Börjesson, J. Am. Chem. Soc., 2019, 14, 124, 9578-9584.

Sep
26
Thu
2019
Cognitive Remediation Therapy confers broad benefits to people with bipolar disorder – Dr Becci Strawbridge, post-doctoral researcher at Institute of Psychiatry, Psychology and Neuroscience at King’s College London
Sep 26 @ 12:30 pm – 1:30 pm

Abstract not available

Fourier, harmonic analysis, and spaces of homogeneous type – Lesley Ward (University of South Australia)
Sep 26 @ 4:00 pm – 5:00 pm
Fourier, harmonic analysis, and spaces of homogeneous type – Lesley Ward (University of South Australia)
Sep 26 @ 4:00 pm – 5:00 pm
Sep
30
Mon
2019
Imaging Transcranial Magnetic Stimulation – Martin Tik, Vienna Medical School
Sep 30 @ 12:30 pm – 1:30 pm

Efforts to improve the effects transcranial magnetic stimulation (TMS) rely heavily on deciphering the underlying mechanisms. Neuroimaging has proven to be very useful in mapping the effects of TMS on brain activity at the systems level. It complements the knowledge, which can be gained from peripheral electrophysiology and behavioral measures. Neuroimaging methods are rapidly evolving, and the latest methodological and hardware developments allow achieving far more specific conclusions on the TMS effects. In this regard, magnetic resonance imaging (MRI) complements TMS in multiple ways:

(1) Anatomical images or fMRI acquired before TMS allows for structural/functional definition of stimulation targets (neuronavigation).
(2) Offline imaging allows for the evaluation of lasting effects after TMS.
(3) Finally, fMRI during TMS, i.e. concurrent TMS/fMRI measures the direct TMS-induced BOLD response.

However, classical TMS/fMRI setups based on large birdcage MR coils are characterised by low sensitivity at the stimulation target. Using an approach based on a dedicated multi-channel MR receive coil mounted underneath the MR-compatible TMS-coil, we show that it is possible to obtain high sensitivity functional imaging data that allows for assessing TMS-induced brain activity on an individual level. The new setup holds the advantage that image acceleration techniques like parallel imaging (GRAPPA, SENSE) and multiband imaging (simultaneous multi-slice imaging, SMS) can be used. Practical issues in applying this method and examples on how to overcome challenges including subject-motion will be discussed.

Oct
3
Thu
2019
Ablative surgeries for psychiatric disorders. The Vancouver capsulotomy and new insights into the neuroanatomy of depression – Professor Trevor Hurwitz, Medical Director, BC Neuropsychiatry Programme, Department of Psychiatry, University of British Columbia
Oct 3 @ 12:30 pm – 1:30 pm

Abstract not available

Oct
8
Tue
2019
Beyond the Energy Frontier: the changing eras of LHCb – Prof. Christopher Parkes (University of Manchester) @ Ryle Seminar Room (Rutherford 930)
Oct 8 @ 3:00 pm – 4:00 pm

The LHCb experiment has recently completed its initial operating period (2010-2018), and has published nearly 500 scientific papers. Highlights of the physics output of the experiment will be reviewed, with an emphasis on recent results such as the discovery of charm CP violation, lepton flavour universality anomalies and observation of pentaquark states. The next era is now starting for LHCb. The Upgrade I experiment is being installed over the next two years for operation from 2021. This will allow a significant increase of instantaneous luminosity and improve efficiencies and flexibility through the introduction of a fully software based trigger at 40MHz. Beyond this the collaboration is planning further upgrades. These will use a range of novel technological developments including precision timing and CMOS based tracking systems with many opportunities for involvement in the research, design and construction activities. Can the third LHCb be a major project for Cavendish III?

How To – An Evening with Randall Monroe – Randall Munroe
Oct 8 @ 7:00 pm – 8:00 pm

Heffers and Cambridge University Scientific Society are delighted to present an evening with Randall Munroe – the man behind the wildly popular webcomic ‘xkcd’ and the million-selling ‘What If?’ and ‘Thing Explainer’ – as he talks about his new book ‘How To’: the world’s most entertaining and useless self-help guide, full of ‘absurd scientific advice for common real-world problems’.

For tickets, visit http://cusshowtoticketonly.eventbrite.co.uk.
For a book and a ticket, visit http://cusshowtobookwithticket.eventbrite.co.uk.
The password is CUSS4HEFFERS. This provides you with discounted tickets valid only with a membership card.

If you won’t be a member, please visit http://howtobookticketwithbook.eventbrite.co.uk, call 01223 463200 or visit the Heffer’s bookshop in Cambridge.

Oct
9
Wed
2019
Autism and the Criminal Justice System – Dr Clare Allely, Reader in Forensic Psychology, University of Salford
Oct 9 @ 10:30 am – 11:30 am

Abstract not available

Adaptation for life on land – remodelling the pharynx in development and evolution – Professor Anthony Graham, King’s College London
Oct 9 @ 1:00 pm – 2:00 pm

The pharynx is an important region of the vertebrate body that is involved in many key processes including feeding, respiratory and vascular functions, immune and endocrine activities. However, with the colonisation of land by vertebrates, the pharynx underwent substantial modification. In this talk, I will discuss the development of the pharynx and how this has been altered to facilitate terrestrial life. To understand how the development of the pharynx has been modified through evolution, we take a comparative approach. This involves analysing pharyngeal development using a range of cellular and molecular approaches: immunostaining, in situ hybridisation, morpholino knockdowns, lineage tracing and pharmacological inhibition of signalling pathways, in embryos that are chosen for the phylogenetic position. We have considered how several features have been altered. The gills and their covering, the operculum, have been lost and the number of embryonic segments reduced. Yet new structures such as the parathyroid glands and larynx have also emerged. Our work is significant as it lays out the developmental changes that underpinned these alterations. It further highlights the progressive nature of evolutionary change and shows that the modifications underpinning the emergence of the tetrapods were not as abrupt as previously believed.

Rapid discovery and chemical synthesis of proteins – Professor Bradley Pentelute, MIT Department of Chemistry
Oct 9 @ 4:00 pm – 5:00 pm

Abstract not available

Oct
10
Thu
2019
Exploratory Data Analysis – Peter Watson, MRC CBU
Oct 10 @ 11:00 am – 12:00 pm

Abstract not available

Prodromal Dementia with Lewy Bodies – Professor Alan Thomas, Professor of Old Age Psychiatry, Newcastle University
Oct 10 @ 12:30 pm – 1:30 pm

Abstract not available

TBD – Kaspar Althoefer, Queen Mary University of London
Oct 10 @ 2:00 pm – 3:00 pm
Title to be confirmed – Prof. Henning Schomerus, Lancaster University
Oct 10 @ 2:15 pm – 3:15 pm

Abstract not available

Coupling of rate-independent and rate-dependent systems with application to delamination processes in solids – Marita Thomas (Weierstrass Institute Berlin) @ MR 14
Oct 10 @ 3:00 pm – 4:00 pm

This talk addresses the modeling of delamination processes in elastic solids
using an internal delamination variable with a rate-independent, unidirectional evolution law.
This covers models for brittle, Griffith-type delamination, which describe sharp
cracks in terms of a non-smooth constraint confining displacement jumps across
interfaces to the null set of the delamination variable, as well as adhesive contact models,
which regularize this constraint by a finite surface energy contribution.
A notion of solution suited for non-smooth PDE-systems of coupled rate-dependent and rate-independent dynamics introduced.
Existence results for the delamination models are deduced.
In this context, for a viscoelastic solid with dynamic effects,
the limit passage from models for adhesive contact to brittle, Griffith-type delamination is discussed in the sense of evolutionary Gamma-convergence.
Fine properties of the solutions are established by studying a simplified model.

Using narratives to understand human conscious experience – Lorina Naci (Trinity College, Dublin)
Oct 10 @ 3:30 pm – 5:00 pm

Abstract not available

Title to be confirmed – Malcolm Fairbairn (King’s College, London)
Oct 10 @ 4:00 pm – 5:00 pm

Abstract not available