Structural reduction of carbon emissions through online education in Dutch Higher Education

Dutch institutions of Higher Education have to meet stringent requirements for energy efficiency andreducing carbon emissions imposed by the national government. The commute of students and staffgreatly contributes to the carbon footprint of a Higher Education Institution. International students inDutch Higher Education also have a substantial impact on the environment due to air travel. Theirnumber increases every year. The deployment and use of ICT can contribute substantially to thereduction of energy use and carbon emissions through decreasing mobility of students and staff byincreasing virtualization and digitalization of educational processes.This exploratory study examines the opportunities of online learning as a means to reduce the impactof students’ traveling on the carbon footprint. The research methodology consists of a systematicreview of literature and a series of interviews with experts of online learning and managers of energy,ICT and/or sustainability.An obstacle for decreasing the carbon footprint of a Higher Education Institution using online learningare differences in opinion as expressed by professionals, regarding the quality of this form ofeducation. Our research shows that those in favour of face-to-face education believe, that the socialprocesses are essential for high quality education. Proponents of online learning emphasize theopportunities by focusing on the advantages for individual students – i.e. giving students more controlover their own learning process. So far, only a minority have recognized that online learning can leadto decreased mobility and a reduction of carbon emissions

A large geometric distortion in the first photointermediate of rhodopsin, determined by double-quantum solid-state NMR

Double-quantum magic-angle-spinning NMR experiments were performed on 11,12-C-13(2)-retinylidene-rhodopsin under illumination at low temperature, in order to characterize torsional angle changes at the C11-C12 photoisomerization site. The sample was illuminated in the NMR rotor at low temperature (similar to 120 K) in order to trap the primary photointermediate, bathorhodopsin. The NMR data are consistent with a strong torsional twist of the HCCH moiety at the isomerization site. Although the HCCH torsional twist was determined to be at least 40A degrees, it was not possible to quantify it more closely. The presence of a strong twist is in agreement with previous Raman observations. The energetic implications of this geometric distortion are discussed

10,20-Metanorhodopsins: (7E,9E,13E)-10,20-methanorhodopsin and (7E,9Z,13Z)-10,20-methanorhodopsin: 11-cis-locked rhodopsin analog pigments with unusual thermal and photo-stability

Bio-organic Synthesi

Helix packing in polytopic membrane proteins: role of glycine in transmembrane helix association.

The nature and distribution of amino acids in the helix interfaces of four polytopic membrane proteins (cytochrome c oxidase, bacteriorhodopsin, the photosynthetic reaction center of Rhodobacter sphaeroides, and the potassium channel of Streptomyces lividans) are studied to address the role of glycine in transmembrane helix packing. In contrast to soluble proteins where glycine is a noted helix breaker, the backbone dihedral angles of glycine in transmembrane helices largely fall in the standard alpha-helical region of a Ramachandran plot. An analysis of helix packing reveals that glycine residues in the transmembrane region of these proteins are predominantly oriented toward helix-helix interfaces and have a high occurrence at helix crossing points. Moreover, packing voids are generally not formed at the position of glycine in folded protein structures. This suggests that transmembrane glycine residues mediate helix-helix interactions in polytopic membrane proteins in a fashion similar to that seen in oligomers of membrane proteins with single membrane-spanning helices. The picture that emerges is one where glycine residues serve as molecular notches for orienting multiple helices in a folded protein complex

Spectral tuning in salamander visual pigments studied with dihydroretinal chromophores.

In visual pigments, opsin proteins regulate the spectral absorption of a retinal chromophore by mechanisms that change the energy level of the excited electronic state relative to the ground state. We have studied these mechanisms by using photocurrent recording to measure the spectral sensitivities of individual red rods and red (long-wavelength-sensitive) and blue (short-wavelength-sensitive) cones of salamander before and after replacing the native 3-dehydro 11-cis retinal chromophore with retinal analogs: 11-cis retinal, 3-dehydro 9-cis retinal, 9-cis retinal, and 5,6-dihydro 9-cis retinal. The protonated Schiff's bases of analogs with unsaturated bonds in the ring had broader spectra than the same chromophores bound to opsins. Saturation of the bonds in the ring reduced the spectral bandwidths of the protonated Schiff's bases and the opsin-bound chromophores and made them similar to each other. This indicates that torsion of the ring produces spectral broadening and that torsion is limited by opsin. Saturating the 5,6 double bond in retinal reduced the perturbation of the chromophore by opsin in red and in blue cones but not in red rods. Thus an interaction between opsin and the chromophoric ring shifts the spectral maxima of the red and blue cone pigments, but not that of the red rod pigment

In or Out? New Insights on Exon Recognition through Splice-Site Interdependency

Contains fulltext : 219583.pdf (publisher's version ) (Open Access

Double-quantum 13C nuclear magnetic resonance of bathorhodopsin, the first photointermediate in mammalian vision

The 13C chemical shifts of the primary visual photointermediate bathorhodopsin have been observed by performing double-quantum magic-angle-spinning NMR at low temperature in the presence of illumination. Strong isomerization shifts have been observed upon the conversion of rhodopsin into bathorhodopsin