Origins of Homochirality

Feb 1, 2008, 9:00 AM → Feb 29, 2008, 6:00 PM Europe/Stockholm

Nordita

Anja C. Andersen (Dark Cosmology Center), Axel Brandenburg (Nordita), Raphaël Plasson (Nordita)

For a list of scheduled talks that are not part of the conference, click here on the page for Nordita talks. Most of the talks contain streaming video recordings. If you want to download an entire lecture (non-streaming), you need to replace the mms in the beginning by http, so you'd say, for example, http://videos.nordita.org/conference/Chirality2008/Soai.wmv

Pictures of all participants.

Conference Schedule
=====================

Monday, 25 February
===================

chair: Axel Brandenburg
 9:00- 9:50 Raphaël Plasson: Thermodynamics of chirality (video,pdf)
10:00-10:50 Cristobal Viedma: When "Left" and "Right" cannot coexist: chiral
                   purity by thermodynamic-kinetic feedback near equilibrium (pdf,ppt)
11:00-11:30 coffee
11:30-12:20 Wim Noorduin: Explanation for the emergence of a single chiral
                          solid state during grinding (video, video2)

12:30-14:00 lunch

chair: Meir Lahav
14:00-14:50 Josep Ribo: Chemical constraints in spontaneous mirror
                        symmetry breaking (video)
15:00-15:30 coffee
15:30-16:20 J. Michael McBride: A mechanism for deracemization by crystal grinding (video,video2)
16:30-17:30 discussion
17:30       reception

Tuesday, 26 February
====================

chair: Commeyras
 9:00- 9:50 Henri Kagan: Nonlinear effects in asymmetric catalysis (video,ppt)
10:00-10:50 Kenso Soai: Asymmetric autocatalysis and origins of homochirality (video)

11:00-11:30 coffee
11:30-12:20 Kouichi Asakura: Emergence of homochirality in chemical systems (video)

12:30-14:00 lunch

chair: Ribo
14:00-14:50 Antonio Rizzo: The ab initio calculation of linear and
                           nonlinear properties of chiral systems (video)

15:00-15:30 coffee
15:30-16:20 tba
16:30-17:20 Günter von Kiedrowski: Systems chemistry and the origin of life (video,ppt)
17:30-18:30 discussion
19:00       Conference Dinner (After Dinner Speach by J. Michael McBride )

Wednesday, 27 February
======================

chair: Asakura
 9:00- 9:50 Laurence Barron: Structure and behaviour of the molecules
                             of life from Raman optical activity (video,pdf,ppt)

10:00-10:50 discussion
11:00-11:30 coffee
11:30-12:20 Yukio Saito: Fluctuation effect on enantiomeric excess
                         amplification and chiral symmetry breaking (video,ppt,ppt2)
12:30-14:00 lunch
            (free afternoon)

Thursday, 28 February
=====================

chair: Kagan
 9:00- 9:50 Armando Cordova: Asymmetric amino acid catalysis (video)

10:00-10:50 Patrick Sandars: The relative handedness of nucleic acids
                             and proteins (video)

11:00-11:30 coffee
11:30-12:20 Auguste Commeyras: Origin of life: the need of steps of
                               concentration (video,ppt,anim1,anim2)

12:30-14:00 lunch

chair: McBride
14:00-14:50 Meir Lahav: Racemic templates for stochastic mirror symmetry breaking (video)

15:00-15:30 coffee
15:30-16:20 Jonathan Wattis: Mathematical models for the emergence
                             of homochirality (video)
16:30-17:30 discussion

Friday, 29 February
===================

chair: Plasson
 9:00- 9:50 Ramadurai: Neutrino induced homochirality (video)

10:00-10:50 Peter Schmidt: Evolution of homochirality: a probabilistic process
                           with simultaneous polymerization, chain degradation
                           and epimerization (video,ppt,ppt2)

11:00-11:30 coffee
11:30-12:20 Sara Walker: Right versus left: why bigger is better
                         (... but not always good enough) (video1,video2)

12:30-14:00 lunch

chair: Barron
14:00-14:50 Axel Brandenburg: Homochirality in spatially extended systems (video,pdf,ppt,htm)
16:00 End of Conference

Background and motivation:

Homochirality is a unique property of living matter. It is a property that gradually disappears after the death of living matter. The origin of homochirality is therefore closely linked to the origin of life, which makes this topic a prominent research field in astrobiology.

The problem of the possible origins of homochirality in living matter is frequently discussed in the literature. On the one hand, physical and external factors (e.g., the electroweak parity breaking, enhanced for example by heavy Cu complexes, as well as magnetic fields and polarized light) are hard to rule out. On the other hand, the possibility of a bifurcation process is quite plausible, but there is no unique mechanism. Possible candidates include autocatalysis combined with enantiomeric cross-inhibition in the RNA world (Sandars 2003) and the activation-polymerization-epimerization-depolymerization reaction of Plasson (2004).

One purpose of this program is to establish the viability of these two different pathways, and to discuss the possibility of an interplay between them. Also the significance of crystallization experiments with stirring either for just demonstrating the effects of growth combined with competition, or as a primitive mechanism under prebiotic conditions should be discussed. Finally, quantitative aspects of approaches of involving physical and external factors should be discussed. Can some quantitative agreement be established regarding the subsequent role of amplification mechanisms and the enantiomeric excess that can be achieved? It is anticipated that such a program can be an important mile stone in this field, which is currently being attacked from the many different angles, without there being sufficient interaction between them.

The program extends over four weeks, where the last week is devoted to a symposium. Although long-term participation is strongly encouraged, it is also possible to stay for shorter periods. The number of program participants is limited to a maximum of about 20 at any time. Funding will be available to accommodate program participants in apartments, whenever possible. Desks and shared office space will be available in the Nordita building.

Program routine

We expect to have only one regular review talk per week. Some of these talks can be oriented toward a broader audience. In addition, we plan to have one extensive discussion session once or twice a week, e.g. between 10:30 and 12:30. Each discussion will be started off by about 3 short presentations (20 min) by program participants talking on a related topic. There should be a vague idea about the topics of each session prior to the begin of the program (to be discussed with the participants via email), but revisions during the course of the program are anticipated. In addition, regular coffee session every morning at 10:00 and at 15:00 provide informal means of exchanging ideas and starting collaborations. Other than that, we try to keep the days open for doing regular work.

Symposium

For the last week (February 25-29) we consider organizing an open symposium that is available to a broader community and, in particular, to people that could not come for the full duration of the program. We are also considering to collect a number of papers for a special issue of Origins of Life and Evolution of the Biosphere. This would allow us to have a permanent record connected with the activities and discussions at the program and/or the open symposium.

Participation

Scientists interested in this progam are encouraged to apply by filling in the registration form. The deadline for applications is December 15, 2007.

Schedule
=========

Tue 5 Feb. 10-12:30: discussion (Jonathan, Susanne, Harry, ...)
Fri 8 Feb Jonathan Wattis (Astrobiology seminar), with reception afterwards
Tue 12 Feb. 10:30: Sara Walker (talk)
Thu, 14 Feb, 14:15: Laurence Barron (talk)
Thu, 15 Feb, 16:15: Meir Lahav (talk)
Fri, 15 Feb, 10:30: Mark Green (talk)
Fri, 15 Feb, 16:00: Guenter von Kiedrowski (Astrobiology seminar), + reception
Sat, 16 Feb, 10:00: Mark Green (discussion)
Sat, 16 Feb, 14:30: Meir Lahav (discussion)
Tue, 19 Feb. 10-12:30: discussion (Asakura, Mashimo, Saito, ...)
Fri, 22 Feb, 16:00: Kouichi Asakura (Astrobiology seminar), with reception
Mon, 25 Feb, 9:00 start of conference (see below)

Arrival/Departure times of Participants, pictures, roster.

Final Report

How to get here? (this link has a description and a map). The meeting takes place in the Nordita building, just next to the AlbaNova main building.

Organizers: Axel Brandenburg, Raphaël Plasson, Anja C. Andersen

Monday, February 25

10:00 AM → 11:00 AM Multidisciplinarity for Homochirality

Speaker: Raphaël Plasson (Nordita)

11:30 AM → 12:30 PM When “Left” and “Right” cannot coexist: chiral purity by thermodynamic-kinetic feedback near equilibrium.

Two populations of chiral crystals of "left" and "right" hand cannot coexist in solution: one of the chiral populations disappears in an irreversible autocatalytic process that nurtures the other one. Final and complete chiral purity seems to be an inexorable fate in our systems in the course of the common process of growth-dissolution. This unexpected chiral symmetry breaking can be explained by the feedback between the thermodynamic control of dissolution and the kinetics of the growth process near equilibrium. We establish this “thermodynamic-kinetic feedback near equilibrium” as a new mechanism to achieve complete chiral purity in solid state from a previously solid racemic medium. This mechanism can operate in solutions of chiral biomolecules and could have played a key role in the origin of biochirality