Tunable variation of optical properties of polymer capped gold nanoparticles

Optical properties of polymer capped gold nanoparticles of various sizes (diameter 3-6 nm) have been studied. We present a new scheme to extract size dependent variation of total dielectric function of gold nanoparticles from measured UV-Vis absorption data. The new scheme can also be used, in principle, for other related systems as well. We show how quantum effect, surface atomic co - ordination and polymer - nanoparticle interface morphology leads to a systematic variation in inter band part of the dielectric function of gold nanoparticles, obtained from the analysis using our new scheme. Careful analysis enables identification of the possible changes to the electronic band structure in such nanoparticles.Comment: 13 pages,7 figures, 1 tabl

Towards Minkowski Vacua in Type II String Compactifications

We study the vacuum structure of compactifications of type II string theories on orientifolds with SU(3)xSU(3) structure. We argue that generalised geometry enables us to treat these non-geometric compactifications using a supergravity analysis in a way very similar to geometric compactifications. We find supersymmetric Minkowski vacua with all the moduli stabilised at weak string coupling and all the tadpole conditions satisfied. Generically the value of the moduli fields in the vacuum is parametrically controlled and can be taken to arbitrarily large values.Comment: 33 pages; v2 minor corrections, references added, version to appear in JHE

Herschel/HIFI measurements of the ortho/para ratio in water towards Sagittarius B2(M) and W31C

We present Herschel/HIFI observations of the fundamental rotational transitions of ortho- and para-H16 2 O and H18 2 O in absorption towards Sagittarius B2(M) and W31C. The ortho/para ratio in water in the foreground clouds on the line of sight towards these bright continuum sources is generally consistent with the statistical high-temperature ratio of 3, within the observational uncertainties. However, somewhat unexpectedly, we derive a low ortho/para ratio of 2.35±0.35, corresponding to a spin temperature of ∼27 K, towards Sagittarius B2(M) at velocities of the expanding molecular ring. Water molecules in this region appear to have formed with, or relaxed to, an ortho/para ratio close to the value corresponding to the local temperature of the gas and dust

Discovery of widespread transcription initiation at microsatellites predictable by sequence-based deep neural network

Using the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of transcription start sites (TSSs) in several species. Strikingly, ~72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probe these unassigned TSSs and show that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we develop Cap Trap RNA-seq, a technology which combines cap trapping and long read MinION sequencing. We train sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveil the importance of STR surrounding sequences not only to distinguish STR classes, but also to predict the level of transcription initiation. Importantly, genetic variants linked to human diseases are preferentially found at STRs with high transcription initiation level, supporting the biological and clinical relevance of transcription initiation at STRs. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism

There is no place like home - why are there so few Swedish scientists in the international research institutes on agriculture and agroforestry?

Sweden contributes large amounts annually to the Consultative Group of International Agriculture Research Organizations (CGIAR), an important body for international Agriculture research. some SEK 80 milion was provided in 1998 alone. But surprisingly few swedish scientists work in International Agriculture Research. Swedish Universities have chosen the home ground and have little organized collaboration with the CGIAR. There is need to change this situation. A policy for international research collaboration is needed between the universities, particularly SLU and there is need for clearer career pathway for students with international interest. Only then can Sweden's financial contribution be matched by action by Swedish scientist in the future

Democratic institutions versus autocratic regimes: The case of environmental policy

The literature suggests that democracy positively affects environmental policy stringency. Using the method of propensity score matching, we find that this result appears to be largely driven by the parliamentary democracies (as opposed to the presidential-congressional, proportional or majority systems). Moreover, it appears that presidential-congressional systems often set environmental policies not significantly different from autocracies. These are novel contributions to the literature. Copyright Springer Science+Business Media, LLC 2007Political institutions, Democracy, Environmental policy, Propensity score matching,