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Seminari  

Il Dipartimento di Fisica ospita Seminari di Dipartimento, Seminari organizzati dai gruppi di ricerca, e Physics Colloquia organizzati dalla Scuola di Dottorato.

I Seminari vengono inseriti nel Calendario.

Di seguito gli eventuali Seminari in programma nel mese in corso:

Seminari  
14/06/2018 Ore 14:30 - 16:00

Quantum metrology under realistic conditions: general noise and ultimate precision limits

14 Giugno 2018 alle 14.30 in Aula Consiglio:
Titolo: "Quantum metrology under realistic conditions: general noise and ultimate precision limits".
Andrea Smirne
Institute for Theoretical Physics, Ulm University
Locandina

13/06/2018 Ore 14:30 - 16:00

Gaps, rings, spirals and holes - signs of newborn planets?

13 Giugno 2018 alle 14.30 in Aula Consiglio:
Titolo:
"Gaps, rings, spirals and holes - signs of newborn planets?"
Dr. Daniel Price
School of Physics and Astronomy, Monash University, Melbourne, Australia
locandina

 

07/06/2018 Ore 12:00 - 15:59

The common origin of symmetry and structure in genetic sequences

7/6/2018 ore 12:00:00 Aula Caldirola

The common origin of symmetry and structure in genetic sequences  
Dr. Giampaolo Cristadoro
Università di Milano-Bicocca


When exploring statistical properties of genetic sequences two main features stand out: the existence of non-random structures at various scales (e.g., long-range correlations) and the presence of symmetries (e.g., Chargaff parity rules). In the last decades, numerous studies investigated the origin and significance of each of these features separately. Here we show that both symmetry and structure have to be considered as the outcome of the same biological processes, whose cumulative effect can be quantitatively measured on extant genomes. We present a novel analysis (based on a minimal model) that not only explains and reproduces previous observations but also predicts the existence of a nested hierarchy of symmetries emerging at different structural scales. Our genome-wide analysis of H. sapiens confirms the theoretical predictions.

stefano.zapperi@unimi.it

http://complexitybiosystems.it/en/events/the-common-origin-of-symmetry-and-structure-in-genetic-sequences

 

 

 

05/06/2018 Ore 12:30 - 16:00

The role of actin cytoskeleton during early stages of pectoral fin shape establishment

5/6/2018 ore 12:30:00 Aula B3 Via Celoria 26 - Milano
The role of actin cytoskeleton during early stages of pectoral fin shape establishment

Dr. Elena Kardash
BioEmergences lab at CNRS, Gif-Sur-Yvette

The mechanism of a three-dimensional shape establishment during vertebrate organogenesis is not fully understood. We used pectoral fin growth in zebrafish as a model for vertebrate limb formation to study the molecular and cellular dynamics leading to the emerging 3D shape. At the early stages of development between 28 and 48 hours post fertilisation (hpf), the fin consists of two cell types: the mesodermal inner mass and an ectodermal outer layer. We show, that at about 36 hpf, fin structure exhibits the simple symmetry of a semi ellipsoid, which later elongates along its anterior-posterior (AP) axis and shortens along its dorso-ventral (DV) axis. We use the ratio between AP and DV axes a readout for fin shape changes to show that AP/DV increases from 1.33 at 32 hpf and to 1.67 at 44 hpf. This anisotropic shape change coincides with an accumulation of a dense actin structure, which we named “actin belt” in the two stripes of ectodermal cells at the most distal rim of the fin bud corresponding to its DV boundary. Using FRET imaging and morpholino-injected embryos, we have shown that Rac activity is essential for actin belt formation and anisotropic shape changes. When actin belt was not present in the morphant embryos with compromised Rac ativity, fin shape retrograded to a shorter semi-ellipsoid geometry as observed at 32 hpf, while its volume and cell number was not affected. Our results suggest a novel mechanism in which an acto-myosin contractile belt promotes fin shape transition from a shorter to a longer semi-ellipsoid.  

stefano.zapperi@unimi.it

http://complexitybiosystems.it/en/events/the-role-of-actin-cytoskeleton-during-early-stages-of-pectoral-fin-shape-establishment

 

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