Efficient analysis of highly complex nuclear magnetic resonance spectra of flexible solutes in ordered liquids by using molecular dynamics

The NMR spectra of n-pentane as solute in the liquid crystal 5CB are measured at several temperatures in the nematic phase. Atomistic molecular dynamics simulations of this system are carried out to predict the dipolar couplings of the orientationally ordered pentane, and the spectra predicted from these simulations are compared with the NMR experimental ones. The simulation predictions provide an excellent starting point for analysis of the experimental NMR spectra using the covariance matrix adaptation evolutionary strategy. This shows both the power of atomistic simulations for aiding spectral analysis and the success of atomistic molecular dynamics in modeling these anisotropic systems. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4705271

‘I already have a culture.’ Negotiating competing grand and personal narratives in interview conversations with new study abroad arrivals

In an interview with a postgraduate student about her intercultural experience of recently arriving for study abroad, it was found that the two researchers and the student were engaged in a mutual exploration of cultural identity. The in- terview events became conversational and took the form of small culture formation on the go in which each participant employed diverse narratives to project, make sense of and negotiate expression of cultural identity. The stu- dent shifted between personal narratives drawn from her particular cultural trajectories and splintered from grand narratives of nation and global position- ing, between non- essentialist threads and essentialist blocks. The researchers learned from her and intervened to facilitate shifts to non-essentialist threads, drawing on narratives from their own personal cultural trajectories, but some- times also falling into essentialist blocks splintered from grand narratives. The roles of ideology and competing essentialist and non-essentialist discourses of culture were implicit in these negotiations, as were the personal agency of the student as she responded to the constraining conflicts, structures and hierarchies encountered through the events she spoke about. Rather than providing a picture of intercultural assimilation and integration, interculturality is revealed as a hesitant and searching negotiation, sometimes of vulnerability, wrong-footedness and occasional assault on identity

Block and thread intercultural narratives and positioning: conversations with newly arrived postgraduate students

This paper considers how, in the process of positioning that is implicit in every interaction, all of us employ multiple and often competing narratives when we talk about cultural identity and our relationships with new cultural environments. In interviews with newly arrived postgraduate students about their experience of travelling to study abroad, the students employ competing block and thread narratives. Block narratives represent an essentialist discourse of culture. As such, they are easily converted into cultural prejudice by blocking the possibility for understanding and sharing at the point of tolerating an Other who can never be like ‘us’. These are default narratives because of the way in which we are brought up in our societies within a global positioning and politics. Thread narratives instead support a critical cosmopolitan discourse of cultural travel and shared meanings across structural boundaries that act against cultural prejudice. Threads need to be nurtured as alternative forms of engagement. Therefore, there is a place for the researchers to intervene with their own thread narratives. This intervention is both allowed within and supported by an understanding that researchers join with their participants in the creative intercultural events of the interview

Social inclusion and professional female migrants in multicultural Australia

The goal of the thesis is to scrutinise the experiences of professional female migrants in Australia. The study was undertaken in the context of the emergence of a policy focus on ‘social inclusion’ and ‘social exclusion’ in Australia and elsewhere and in the context of renewed debates in Australia about multiculturalism. Social inclusion refers to a policy focus on enabling the full participation of citizens in the life of the nation, including economic, social, cultural and political participation (Gillard & Wong, 2007). In turn, social exclusion refers to a policy focus on identifying and addressing groups whose participation is constrained, often measured along the dimensions of consumption, production, political engagement, social support and cultural life (see for example, Burchardt, Le Grand, & Piachaud, 2002; Richardson & Le Grand, 2002). This research is interested in testing the relevance of these frameworks for understanding and addressing the experiences of professional female migrants in multicultural Australia. The thesis involved a study of twenty professional female migrants living in Sydney who participated in in-depth interviews. All respondents belonged to a highly skilled occupational group and a prerequisite was that they held a primary professional qualification before migration to Australia. Participants, who were from both English speaking and non-English speaking backgrounds provided detailed narratives of their lives and experiences since migration to Australia, and these narratives provided a window into the specificities of professional female migrants’ perceptions of moving to Australia, settling in Australia and ‘belonging’ in Australia. These insights add to the body of knowledge on migration and social inclusion and exclusion. The research found that the relevance of the dominant social inclusion framework for analysing their migration and settlement experiences is only partial: this is because of the prioritisation of economic participation as a route to social inclusion. The social inclusion framework, consequently, fails to recognise the cultural dimension of social inclusion by assuming that social inclusion in multicultural Australia can be achieved and maintained through the active economic participation of Australian citizens. In addition, the study found that the dominant social inclusion policy framework does not recognise an important aspect of professional female migrants’ identity: transnational relationships and transnational belonging. In terms of the specificities of professional female migrants’ experiences, the thesis proposes a structure for talking about differences in experiences of inclusion that uses measures such as participation in paid work, either in mainstream or in ethno-specific workplaces; participation in social life, either in or in and beyond their own ethnic community; self-perception of being, or not being, included - a dimension that was often based on whether or not they experienced racism. Based on these factors, women’s experiences could be categorised as varying between deep, borderline, marginal and shallow inclusion. The thesis also finds that although social inclusion does not equal assimilation or a transition from being a migrant, social inclusion is possible in the context of ethnic and cultural differences

Joint diffraction and modeling approach to the structure of liquid alumina

The structure of liquid alumina at a temperature ∼2400 K near its melting point was measured using neutron and high-energy x-ray diffraction by employing containerless aerodynamic–levitation and laser-heating techniques. The measured diffraction patterns were compared to those calculated from molecular dynamics simulations using a variety of pair potentials, and the model found to be in best agreement with experiments was refined using the reverse Monte Carlo method. The resultant model shows that the melt is composed predominantly of AlO4 and AlO5 units, in the approximate ratio of 2:1, with only minor fractions of AlO3 and AlO6 units. The majority of Al-O-Al connections involve corner-sharing polyhedra (83%), although a significant minority involve edge-sharing polyhedra (16%), predominantly between AlO5 and either AlO5 or AlO4 units. Most of the oxygen atoms (81%) are shared among three or more polyhedra, and the majority of these oxygen atoms are triply shared among one or two AlO4 units and two or one AlO5 units, consistent with the abundance of these polyhedra in the melt and their fairly uniform spatial distribution

Development of an enzyme-linked immunosorbent assay for the detection of human calretinin in plasma and serum of mesothelioma patients

<p>Abstract</p> <p>Background</p> <p>Calretinin is one of the well-established immunohistochemical markers in the diagnostics of malignant mesothelioma (MM). Its utility as a diagnostic tool in human blood, however, is scarcely investigated. The aim of this study was to develop an enzyme-linked immunosorbent assay (ELISA) for human calretinin in blood and to assess its usefulness as a potential minimally invasive diagnostic marker for MM.</p> <p>Methods</p> <p>Initially, attempts were made to establish an assay using commercially available antibodies and to optimize it by including a biotin-streptavidin complex into the assay protocol. Subsequently, a novel ELISA based on polyclonal antibodies raised in rabbit immunized with human recombinant calretinin was developed. The assay performance in human serum and plasma (EDTA/heparin) and the influence of calcium concentrations on antibody recognition were studied. Stability of spiked-in calretinin in EDTA plasma under different storage conditions was also examined. In preliminary studies serum and plasma samples from 97 healthy volunteers, 35 asbestos-exposed workers, and 42 MM patients were analyzed.</p> <p>Results</p> <p>The mean detection range of the new ELISA was 0.12 to 8.97 ng/ml calretinin. The assay demonstrated markedly lower background and significantly higher sensitivity compared to the initially contrived assay that used commercial antibodies. Recovery rate experiments confirmed dependence of calretinin antibody recognition on calcium concentration. Calcium adjustment is necessary for calretinin measurement in EDTA plasma. Spiked-in calretinin revealed high stability in EDTA plasma when stored at room temperature, 4°C, or after repeated freeze/thaw cycles. Median calretinin values in healthy volunteers, asbestos workers, and MM patients were 0.20, 0.33, and 0.84 ng/ml, respectively (p < 0.0001 for healthy vs. MM, p = 0.0036 for healthy vs. asbestos-exposed, p < 0.0001 for asbestos-exposed vs. MM). Median values in patients with epithelioid and biphasic MM were similar. No influence of age, gender, smoking status, or type of medium (plasma/serum) on calretinin values was found.</p> <p>Conclusions</p> <p>The novel assay is highly sensitive and applicable to human serum and plasma. Calretinin appears to be a promising marker for the blood-based detection of MM and might complement other markers. However, further studies are required to prove its usefulness in the diagnosis of MM patients.</p

A Stochastic Description of Dictyostelium Chemotaxis

Chemotaxis, the directed motion of a cell toward a chemical source, plays a key role in many essential biological processes. Here, we derive a statistical model that quantitatively describes the chemotactic motion of eukaryotic cells in a chemical gradient. Our model is based on observations of the chemotactic motion of the social ameba Dictyostelium discoideum, a model organism for eukaryotic chemotaxis. A large number of cell trajectories in stationary, linear chemoattractant gradients is measured, using microfluidic tools in combination with automated cell tracking. We describe the directional motion as the interplay between deterministic and stochastic contributions based on a Langevin equation. The functional form of this equation is directly extracted from experimental data by angle-resolved conditional averages. It contains quadratic deterministic damping and multiplicative noise. In the presence of an external gradient, the deterministic part shows a clear angular dependence that takes the form of a force pointing in gradient direction. With increasing gradient steepness, this force passes through a maximum that coincides with maxima in both speed and directionality of the cells. The stochastic part, on the other hand, does not depend on the orientation of the directional cue and remains independent of the gradient magnitude. Numerical simulations of our probabilistic model yield quantitative agreement with the experimental distribution functions. Thus our model captures well the dynamics of chemotactic cells and can serve to quantify differences and similarities of different chemotactic eukaryotes. Finally, on the basis of our model, we can characterize the heterogeneity within a population of chemotactic cells

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Renal malformations associated with mutations of developmental genes: messages from the clinic

Renal tract malformations (RTMs) account for about 40% of children with end-stage renal failure. RTMs can be caused by mutations of genes normally active in the developing kidney and lower renal tract. Moreover, some RTMs occur in the context of multi-organ malformation syndromes. For these reasons, and because genetic testing is becoming more widely available, pediatric nephrologists should work closely with clinical geneticists to make genetic diagnoses in children with RTMs, followed by appropriate family counseling. Here we highlight families with renal cysts and diabetes, renal coloboma and Fraser syndromes, and a child with microdeletion of chromosome 19q who had a rare combination of malformations. Such diagnoses provide families with often long-sought answers to the question “why was our child born with kidney disease”. Precise genetic diagnoses will also help to define cohorts of children with RTMs for long-term clinical outcome studies

Dispersion, solvent and metal effects in the binding of gold cations to alkynyl ligands: implications for Au(i) catalysis.

The coordination modes of the [Au(PPh3)](+) cation to metal alkynyl complexes have been investigated. On addition to ruthenium, a vinylidene complex, [Ru(η(5)-C5H5)(PPh3)2([double bond, length as m-dash]C[double bond, length as m-dash]CPh{AuPPh3})](+), is obtained while addition to a gold(iii) compound gives di- and trinuclear gold complexes depending on the conditions employed. In the trinuclear species, a gold(i) cation is sandwiched between two gold(iii) alkynyl complexes, suggesting that coordination of multiple C-C triple bonds to gold is facile