Abstracts

Carolina Barillas-Mury

Mosquito Immune Priming in Response to Plasmodium Infection

Immune priming is triggered when Plasmodium parasites invade the midgut and break the barriers that normally prevent direct contact of bacteria from the gut microbiota with epithelial cells. Priming involves the release of a hemocyte differentiation factor (HDF) into the mosquito hemolymph that triggers a permanent state of enhanced immune surveillance by hemocytes, and allows mosquitoes to mount a more effective immune response to subsequent challenges with Plasmodium. A similar response is elicited when hemolymph from challenged mosquitoes containing HDF is transferred into naïve recipients. HDF consists of Lipoxin A4 bound to Evokin (a lipid carrier of the lipocalin family).  Innate immune priming in mosquitoes involves a persistent increase in Evokin expression and enhanced ability to convert arachidonic acid to lipoxins, predominantly Lipoxin A4. The strength of the priming response is greater in the less compatible mosquito-parasite pairs. The Toll, Imd, STAT or JNK signaling cascades are not essential for the production of hemocyte differentiation factor (HDF) in response to P. berghei infection, but disruption of Toll, STAT or JNK abolishes hemocyte differentiation in response to HDF.  Hemocytes are key players in the activation of the complement-like system, through an effector(s) regulated by the Toll pathway.  Recent studies revealed that midgut nitration triggers the local release of hemocyte-derived microvesicles (HdMv) into the basal labyrinth of the midgut. Contact of hemocytes with the nitrated midgut basal surface triggers HdMv release. This response is necessary for effective activation of mosquito complement and is enhanced by immune priming. Midgut epithelial cells produce prostaglandins when they come in direct contact with bacteria from the gut microbiota.  Prostaglandin release attracts hemocytes to the basal surface of the midgut, increases their motility as they patrol this interphase and is necessary to establish immune priming.


Pablo Castillo

Presynaptic plasticity: novel functions and mechanisms

Long-term synaptic plasticity (LTP/LTD) is critical for experience-induced neural adaptations in the brain. Synaptic plasticity can occur as a result of postsynaptic receptor modifications, or changes in amount of neurotransmitter released per action potential. While most research has focused on the mechanisms that underlie postsynaptic forms of plasticity, comparatively little is known about how neurotransmitter release is altered in a long-term manner. Importantly, increasing evidence indicates that presynaptic plasticity is a potent regulator of circuit output and likely underlies some forms of learning. In this lecture, Dr. Pablo Castillo (Professor of Neuroscience, Albert Einstein College of Medicine) will discuss recent discoveries on major molecular and cellular mechanisms underlying presynaptic plasticity in the rodent hippocampus.


Michal Koucky

Catalytic computation

Every year we buy larger and larger hard-drives and more and more computer memory. We use them to store, manipulate and process data. The amount of space needed to store data is well understood by now. However, we still do not understand very well the amount of space needed to process data.

On algorithmic side computer scientists are trying to design algorithms that require little space to process data, on computational complexity side researchers are trying to establish the minimum space needed to process data. The former led to development of for example streaming algorithms. The latter endeavor turns out to be substantially more difficult, and good understanding of space is still rather elusive.

I will demonstrate the difficulties on the recent discovery of catalytic computation. Catalytic computation uses memory already occupied by data to process other data while preserving the original data in the memory. This leads to algorithms that were thought to be impossible, and challenges our understanding of memory and computational space.


Julien Laurat

Stopping the light: a quantum memory for future information networks

Quantum mechanics led lo many breakthroughs, which have revolutionized our daily life. Among others, the laser or the transistor, which enabled the fast development of computers. More recently, in particular after first thoughts pushed forward by Richard Feynman, it has also been realized that the quantum nature of information can be exploited for totally new modes of communication and computation. ‘Quantum Information Science’ has thus developed driven by the prospect to exploit capabilities from the quantum realm to accomplish tasks difficult or even impossible with traditional methods of information processing.

In this context, quantum information networks, which may lead to our future ”quantum internet” [1], require the ability to faithfully map back and forth flying quantum information, namely the quantum state of light pulse, into nodes based on material systems. In the last few years, great efforts have been directed towards this requisite, involving different architectures and materials. In this talk, I will present the importance of such quantum memories and the developed techniques for implementing them [2].
In more details, I will describe a recent experiment performed in my group where we succeeded to stop light that propagates in an optical fiber and to release it later on demand, demonstrating in this way an all-fibered quantum memory [3]. At the core of the device is a commercial fiber, with a short section elongated to 400 nanometers in in diameter where the light can efficiently interact with a cloud of laser-cooled atoms. Using the so-called electromagnetically induced transparency technique, we slowed down the light pulse by 3000-fold and then halted it completely. The information conveyed by the laser light is transferred to the atoms in the form of a collective excitation, a large quantum superposition. Around 2000 cesium atoms very close to the fiber were involved in the process. Later, after a programmable time, the light was released into the fiber, reconstituting the initial encoded information that can once again travel. Storage times up to 5 microseconds were demonstrated, corresponding to a traveling distance of 1 km if the light had not been halted.

[1] H.J. Kimble, The quantum internet, Nature 453, 1023 (2008)
[2] A. Nicolas et al., A quantum memory for orbital angular momentum photonic qubits, Nature Photonics 8, 234 (2014).
[3] B. Gouraud et al., Demonstration of a memory for tightly guided light in an optical nanofiber, Phys. Rev. Lett. 114, 180503 (2015).


Olgica Milenkovic

Portable and Random-Access DNA-Based Storage Systems

Despite the many advances in traditional data recording techniques, the surge of Big Data platforms and energy conservation issues have imposed new challenges to the storage community in terms of identifying extremely high volume, non-volatile and durable recording media. To address these challenges, the new paradigm of macromolecular storage was put forward by a number of researchers. Among all macromolecules used, DNA stands out in so far that it lends itself to implementations of recoding media of outstanding integrity and extremely high storage capacity.
Building upon the rapid growth of biotechnology systems for DNA synthesis and sequencing, we developed and implemented the first portable DNA-based rewritable and random access device. Our system is based on DNA editing, new alignment algorithms and constrained and error-control coding techniques that ensure data reliability, specificity and sensitivity of access, and at the same time, provide exceptionally high data storage capacity. The coding methods used include prefix-synchronized codes, and newly introduced profile codes and codes in the Damerau distance. As a proof of concept, we encoded in DNA parts of the Wikipedia pages of six universities in the USA and Citizen Kane images, selected specific content blocks and edited portions of the text within various positions in the blocks. We showed that error-free readouts may be achieved even with noisy nanopore MinION readout platforms.


Karl Sigmund

People will remember

Much of human memory concerns social interactions, and includes reputation systems both for those who are near and those

who are far from us. Human communication, in various forms of gossip, deals to a major part with informations about third parties. My talk will use simple
methods from evolutionary game theory to discuss the role of reputation in the evolution of cooperation, and consider models of indirect reciprocity,
fair sharing, reward and punishment. Such models concern central issues in human evolution, moral philosophy, and e-trading.