Site-specific labelling of proteins with a rigid lanthanide-binding tag

This paper describes a generic method for the site-specific attachment of lathanide complexes to proteins through a disulfide bond. The method is demonstrated by the attachment of a lanthanide-binding peptide tag to the single cysteine residue present in the N-terminal DNA-binding domain of the Echerichia coli arginine repressor. Complexes with Y3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+ and Yb3+ ions were formed and analysed by NMR spectroscopy. Large pseudocontact shifts and residual dipolar couplings were induced by the lanthanide-binding tag in the protein NMR spectrum, a result indicating that the tag was rigidly attached to the protein. The axial components of the magnetic susceptibility anisostropy tensors determined for the different lanthanide ions were similarly but not identically oriented. A single tag with a single protein attachment site can provide different pseudocontact shifts from different magnetic susceptibility tensors and thus provide valuable nondegenerate long-range structure information in the determination of 3D protein structures by NMR spectroscopy.

Automatic labelling of topic models learned from Twitter by summarisation

Latent topics derived by topic models such as Latent Dirichlet Allocation (LDA) are the result of hidden thematic structures which provide further insights into the data. The automatic labelling of such topics derived from social media poses however new challenges since topics may characterise novel events happening in the real world. Existing automatic topic labelling approaches which depend on external knowledge sources become less applicable here since relevant articles/concepts of the extracted topics may not exist in external sources. In this paper we propose to address the problem of automatic labelling of latent topics learned from Twitter as a summarisation problem. We introduce a framework which apply summarisation algorithms to generate topic labels. These algorithms are independent of external sources and only rely on the identification of dominant terms in documents related to the latent topic. We compare the efficiency of existing state of the art summarisation algorithms. Our results suggest that summarisation algorithms generate better topic labels which capture event-related context compared to the top-n terms returned by LDA. © 2014 Association for Computational Linguistics.

Phytoplankton-bacteria coupling under elevated CO2 levels: a stable isotope labelling study, 2010

The potential impact of rising carbon dioxide (CO2) on carbon transfer from phytoplankton to bacteria was investigated during the 2005 PeECE III mesocosm study in Bergen, Norway. Sets of mesocosms, in which a phytoplankton bloom was induced by nutrient addition, were incubated under 1x (~350 µatm), 2x (~700 µatm), and 3x present day CO2 (~1050 µatm) initial seawater and sustained atmospheric CO2 levels for 3 weeks. 13C labelled bicarbonate was added to all mesocosms to follow the transfer of carbon from dissolved inorganic carbon (DIC) into phytoplankton and subsequently heterotrophic bacteria, and settling particles. Isotope ratios of polar-lipid-derived fatty acids (PLFA) were used to infer the biomass and production of phytoplankton and bacteria. Phytoplankton PLFA were enriched within one day after label addition, whilst it took another 3 days before bacteria showed substantial enrichment. Group-specific primary production measurements revealed that coccolithophores showed higher primary production than green algae and diatoms. Elevated CO2 had a significant positive effect on post-bloom biomass of green algae, diatoms, and bacteria. A simple model based on measured isotope ratios of phytoplankton and bacteria revealed that CO2 had no significant effect on the carbon transfer efficiency from phytoplankton to bacteria during the bloom. There was no indication of CO2 effects on enhanced settling based on isotope mixing models during the phytoplankton bloom, but this could not be determined in the post-bloom phase. Our results suggest that CO2effects are most pronounced in the post-bloom phase, under nutrient limitation.

A two-step fluorinase enzyme mediated 18F labelling of an RGD peptide for positron emission tomography

Peer reviewed

A two-step fluorinase enzyme mediated 18F labelling of an RGD peptide for positron emission tomography

Peer reviewed

A two-step fluorinase enzyme mediated 18F labelling of an RGD peptide for positron emission tomography

Peer reviewed

From labelling to social aid for immigrants in the 21st Century

Migration is as old as humanity, but since the 1990s migration flows in Western Europe have led to societies that are not just multicultural but so-called «super-diverse». As a result, Western towns now have very complex social structures, with amongst others large amounts of small immigrant communities that are in constant change. In this paper we argue that for social workers to be able to offer adequate professional help to non-native residents in town, they will need balanced view of ‘culture’ and of the role culture plays in social aid. Culture is never static, but is continually changing. By teaching social workers about how to look at cultural backgrounds of immigrant groups and about the limitations of then role that culture plays in communication, they will be better equipped to provide adequate aid and will contribute to making various groups grow towards each other and to avoid people thinking in terms of ‘out-group-homogeneity’. Nowadays, inclusion is a priority in social work that almost every social worker supports. Social workers should have an open attitude to allow them to approach every individual as a unique person. They will see the other person as the person they are, and not as a part of a specific cultural group. Knowledge about the others makes them see the cultural heterogeneity in every group. The social sector, though, must be aware not to fall into the trap of the ‘inclusion mania’! This will cause the social deprivation of a particular group to be forgotten. An inclusive policy requires an inclusive society. Otherwise, this could result in even more deprivation of other groups, already discriminated against. Emancipation of deprived people demands a certain target-group policymaking. Categorized aid will raise efficiency of working with immigrants and of acknowledging the cultural identity of the non-natives group. It will also create the possibility to work on fighting social deprivation, in which most immigrants can be found.

Chinese Men and "Leftover Women" : How do Chinese Men Position Themselves in Relation to the Concept of Labelling Women as "Leftover"?

In recent years there has been a resurgence of gender inequality in China. Today, women are pressured to get married by the state and their social surroundings, as they told if they remain unmarried and have the "three highs"; high age, education and salary, they will become leftovers on the marriage market. Previous research on the concept of labelling women as "leftover" has 4 shown that labelling women as "leftover" can have several different negative impacts. In this thesis, both the theory of masculine hegemony and the theory of symbolic interaction have been used. The concept creates a hegemonic masculinity as it is a normative practice that promotes the subordination of women. However, as the concept is based on the notion that all Chinese men, or at least those of relevant social standing, would find the "three highs" undesirable, it is relevant to see how Chinese men in fact do position themselves in relation to the hegemonic masculinity on an individual level. In symbolic interaction, the concept of gender is created through social construction when people attach special meanings to the sex of a person, a process which is called "doing gender". Therefore symbolic interaction is used to see what special meaning Chinese men attach to women having the "three highs" and masculine hegemony to put their answers into a larger context. If it could be shown that Chinese men do not comply with the hegemonic masculinity, Chinese women would not have to feel obliged to adjust to the hegemonic masculinity and thereby making it easier for them to pursue higher education, high paying jobs and marrying at a later age. However, as this thesis is a qualitative study, and therefore a limited number of data subjects, the generalizability of the result should not be exaggerated. The interviews that were conducted for this thesis showed that the data subjects were familiar with the concept and that they considered it to be natural for there to be women China labelled as "leftover". Nevertheless, in relation to their own marital choices, the data subjects did not attach the negative meaning as set out by the hegemonic masculinity, a result which to some extent was confirmed by the data subjects’ experiences and other control questions. The result is interesting, and enforces Connell and MesserSchmidt’s theory, that even though a hegemonic masculinity is normative, not everyone has to comply with it. As the cornerstone of the concept is that Chinese men find women with the "three highs" undesirable, the result of the study shows that there is a need for the concept to be further examined and questioned.