Tidlegare arrangement - Side 294

Iker S. Requerey, IAC, Spain

Microfluidics of sugar transport in plants

Plants can rightly be called masters of microengineering. Their survival and successful reproduction depends on their ability to overcome a series of physical challenges during growth and when transporting matter over great distances. In this talk, we focus on the microfluidic network responsible for energy distribution (the phloem). We combine experiments on living plants and biomimetic microfluidic devices to elucidate the basic physical principles that govern sugar transport in plants. We derive a scaling relation between the characteristic sizes of the plant organs, which optimizes the rate of sugar transport. Comparison with experimental data suggests that the pipe network is operating at or near the theoretical optimum. We further consider the coupling between photosynthesis and long-distance transport. While sap with high sugar concentration has the greatest transport potential, viscosity impedes flow, a phenomena analogous to congestion in traffic flows. The optimal sugar concentration for transport in plants is 25%, sweeter than Coke (10%) but much less viscous than maple syrup (65%). Although plants have generally evolved towards the theoretical optimum, a number of unusually sweet plants exist. This group consists primarily of crop plants such as corn (40%) and potato (50%), sugar junkies of the natural world.

This Friday the journal club will discuss a paper by Sakamoto et al. (2016): ‘Residual diversity estimates’ do not correct for sampling bias in palaeodiversity data.

Join us!

Velkommen til filmvisning av kritikerroste Ex Machina og foredrag om engstelse for den kvinnelige roboten og hvordan denne filmen henger sammen med oldtidens mytologier og religion. Få med deg det første Science of Fiction-arrangementet.

This thursday, at the Speciation Journal Club, we will discuss a paper entitled "Genomic variation at the tips of the adaptive radiation of Darwin's finches" by Chaves et al. 2016 in Molecular Ecology.

Læraranes årlege etterutdanningsdag ved UiO arrangeres i år torsdag 3. november på Blindern. Her kan lærarar få med seg aktuelle foredrag i fag dei underviser i eller tema som dei er interessert i å læra meir om. Institutt for geofag og NHM deltar med tre foredrag på Fagleg pedagogisk dag i 2016.

Jeriek Van den Abeele, FI

Given that physical problems rarely have exact solutions, the importance of perturbation theory can hardly be overstated. Yet often, a closer look reveals that it is divergent and ill-defined! Non-perturbative effects, ubiquitous in nature and quantum theories, have to be accounted for explicitly in attempts to make sense of perturbation theory. The perspective of the resurgence framework leads to new ways of understanding perturbative expansions and reveals surprising connections to non-perturbative physics. In this talk, I will illustrate how resurgence manifests itself in the quantum mechanical context of a cosine potential, emphasising the importance of quantum tunnelling for its energy spectrum and highlighting how non-perturbative contributions are intricately encoded in perturbation theory.

(The slides will be available here)

Geometry and sedimentary facies of low-angle clinoforms, Edgeøya, Svalbard

Azadeh Abravan, Department of Physics, UiO

Dr Perrine Geraudie, Akvaplan Niva

Invitasjon til fagkonferanse om miljøgeologi/geokjemi: The Tømte Symposium.

Prof Per Mykland (University of Chicago) will give a seminar in the lunch area, 8th floor Niels Henrik Abels hus at 14:15.

In this talk I will explain how the use of functors defined on the category I of finite sets and injections makes it possible to replace E-infinity objects by strictly commutative ones. For example, an E-infinity space can be replaced by a strictly commutative monoid in I-diagrams of spaces. The quasi-categorical version of this result is one building block for an interesting rigidification result about multiplicative homotopy theories: we show that every presentably symmetric monoidal infinity-category is represented by a symmetric monoidal model category. (This is based on joint work with C. Schlichtkrull, with D. Kodjabachev, and with T. Nikolaus)   

Mechanisms of Risk for Cardiovascular Disease Related to Welding

Diseases can induce detectible genetic changes in host populations by exerting infectious pressure. It has been hypothesized that past plague pandemics have shaped susceptibility to infections in modern European populations. In this journal club, we will discuss immune pathways that have been shaped by convergent evolution in European and Rroma populations in response to plague and other infections.

”DNA damage in Arctic seabirds: baseline, sensitivity to oxidative stress and association to contaminants”

”Thermal reaction norms for larval Atlantic cod (Gadus morhua). Exploring population differences on a micro-geographic scale”

Clara Froment, Postdoc , ITA

Join us on PharmaTox open seminar series.

Attendance is free and open for everybody. Registration is required.

Estimates of fishing mortality commonly used in stock assessment models are often conditional on restrictive assumptions about natural mortality. However, integrating data from various sources in bayesian state-space models can allow to independently estimate mortalities of different sources.

This thursday, at the Speciation Journal Club, we will discuss a paper entitled "detection of human adaptation during the past 2000 years" by Field et al. 2016 in Science.

27. oktober arrangeres et seminar i samfunnsfarmasi for å markere professor Else-Lydia Toveruds verdifulle innsats for farmasien gjennom mange år.