Spinning nanorods - active optical manipulation of semiconductor nanorods using polarised light

In this Letter we show how a single beam optical trap offers the means for three-dimensional manipulation of semiconductor nanorods in solution. Furthermore rotation of the direction of the electric field provides control over the orientation of the nanorods, which is shown by polarisation analysis of two photon induced fluorescence. Statistics over tens of trapped agglomerates reveal a correlation between the measured degree of polarisation, the trap stiffness and the intensity of the emitted light, confirming that we are approaching the single particle limit.Comment: 7 pages, 4 figure

Relationship of hyperglycaemia, hypoglycaemia, and glucose variability to atherosclerotic disease in type 2 diabetes

Objective: Type 2 diabetes mellitus (T2DM) is known to be associated with increased cardiovascular risk. The aim of this study was therefore to investigate the independent effects of hyperglycaemia, hypoglycaemia, and glucose variability on microvascular and macrovascular disease in T2DM. Methods. Subjects with T2DM of 7.8mmol/L (β=15.83, p=0005) was the sole independent predictor of albuminuria in generalised linear regression. Conclusions. This study demonstrates that hypoglycaemia is associated with the occurrence of atherosclerotic disease while hyperglycaemia is associated with microvascular disease in a Caucasian population with T2DM of recent duration.peer-reviewe

Dual adaptive dynamic control of mobile robots using neural networks

This paper proposes two novel dual adaptive neural control schemes for the dynamic control of nonholonomic mobile robots. The two schemes are developed in discrete time, and the robot's nonlinear dynamic functions are assumed to be unknown. Gaussian radial basis function and sigmoidal multilayer perceptron neural networks are used for function approximation. In each scheme, the unknown network parameters are estimated stochastically in real time, and no preliminary offline neural network training is used. In contrast to other adaptive techniques hitherto proposed in the literature on mobile robots, the dual control laws presented in this paper do not rely on the heuristic certainty equivalence property but account for the uncertainty in the estimates. This results in a major improvement in tracking performance, despite the plant uncertainty and unmodeled dynamics. Monte Carlo simulation and statistical hypothesis testing are used to illustrate the effectiveness of the two proposed stochastic controllers as applied to the trajectory-tracking problem of a differentially driven wheeled mobile robot.peer-reviewe

GEOMORFOLOGIA E ENSINO: A INSERÇÃO DE JOGOS DIDÁTICOS PARA TRABALHAR O CONTEÚDO PROGRAMÁTICO

Sabe-se que os métodos tradicionais de ensino são importantes, entretanto estão se tornando cada vez mais desinteressantes. A inserção da Geomorfologia como conteúdo programático pode se tornar desafiador ao professor, devido à dificuldade em trabalhar um tema tão abstrato, logo, o objetivo desse trabalho é propor melhor método de ensino através de jogos didáticos e dinâmicas para uma interação mais lúdica e fácil com o conteúdo

Characterisation of synoptic conditions and cyclones associated with top ranking potential wind loss events over Iberia

Intense extra-tropical cyclones are often associated with strong winds, heavy precipitation and socio-economic impacts. Over southwestern Europe, such storms occur less often, but still cause high economic losses. We characterise the largescale atmospheric conditions and cyclone tracks during the top-100 potential losses over Iberia associated with wind events. Based on 65 years of reanalysis data,events are classified into four groups: (i) cyclone tracks crossing over Iberia on the event day (“Iberia”), (ii) cyclones crossing further north, typically southwest of the British Isles (“North”), (iii) cyclones crossing southwest to northeast near the northwest tip of Iberia (“West”), and (iv) so called “Hybrids”, characterised by a strong pressure gradient over Iberia due to the juxtaposition of low and high pressure centres. Generally, “Iberia” events are the most frequent (31% to 45% for top-100 vs.top-20), while “West” events are rare (10% to 12%). 70% of the events were primarily associated with a cyclone. Multi-decadal variability in the number of events is identified. While the peak in recent years is quite prominent, other comparably stormy periods occurred in the 1960s and 1980s. This study documents that damaging wind storms over Iberia are not rare events, and their frequency of occurrence undergoes strong multi-decadal variability

Dynamical Casimir effect in a Josephson metamaterial

Vacuum modes confined into an electromagnetic cavity give rise to an attractive interaction between the opposite walls. When the distance between the walls is changed non-adiabatically, virtual vacuum modes are turned into real particles, i.e. photons are generated out of the vacuum. These effects are known as the static and dynamical Casimir effect, respectively. Here we demonstrate the dynamical Casimir effect using a Josephson metamaterial embedded in a microwave cavity at 5.4 GHz. We achieve the non-adiabatic change in the effective length of the cavity by flux-modulation of the SQUID-based metamaterial, which results in a few percent variation in the velocity of light. We show that energy-correlated photons are generated from the ground state of the cavity and that their power spectra display a bimodal frequency distribution. These results are in excellent agreement with theoretical predictions, all the way to the regime where classical parametric effects cannot be of consequence.Comment: 4 pages, 3 figures, supplement at http://ltl.tkk.fi/~pjh/DCE

CYP2C19 genetic polymorphisms in Maltese patients on clopidogrel therapy

Introduction and Aims: The prevalence of CYP2C19 genetic polymorphisms in the Maltese population is not reported. The aims were to determine CYP2C19 *2 and *17 allele frequencies and CYP2C19 genotype distribution in a cohort of Maltese patients on clopidogrel and to compare observed frequencies of the CYP2C19 *2 allele and *2/*2 genotype to other populations bordering the Mediterranean Sea. Methods: Genotyping for the CYP2C19 *2 and *17 alleles in Maltese patients on clopidogrel was performed using TaqMan® drug metabolism assays. The frequency of both alleles and six genotypes (*1/*1, *1/*2, *2/*2, *1/*17, *17/*17, *2/*17) were determined. Observed frequencies of the CYP2C19 *2 allele and *2/*2 genotype were compared to fourteen populations bordering the Mediterranean Sea (p>0.05 indicated similar prevalence) Results: Frequencies of the CYP2C19 *2 and *17 alleles in the 244 patients genotyped were 12.3% and 15.4% respectively. CYP2C19 genotype distribution was: *1/*1 (52.1%), *1/*17 (22.5%), *1/*2 (18.0%), 2/*17 (6.6%), *17/*17 (0.8%) and *2/*2 (0). Prevalence of the *2 allele in the Maltese cohort was similar to all fourteen populations bordering the Mediterranean Sea, while prevalence of *2/*2 was similar to Egyptian, Moroccan, Southern French, Slovenian, Turkish and Tunisian populations (p>0.05). Conclusions: This study provides an indication of the prevalence of CYP2C19 polymorphisms in Maltese patients. The high percentage of patients with CYP2C19 IM or UM phenotype demonstrates that CYP2C19 genotyping could aid clinicians to individualise treatment with clopidogrel and other drugs metabolised by the CYP2C19 enzyme.peer-reviewe

CYP2C19*2 allele carrier status and coronary in-stent restenosis : is there an association?

Background and objective: The CYP2C19*2 allele is associated with reduced clopidogrel bioactivation, increasing the risk of complications after percutaneous coronary intervention (PCI), particularly stent thrombosis. Recently published data suggests that CYP2C19*2 allele carriers have a higher risk for in-stent restenosis (ISR) after endovascular treatment. Very few studies have investigated the relationship between CYP2C19*2 and coronary ISR, with no significant association reported. The objective of this study was to assess the relationship between CYP2C19*2 allele carrier status and coronary ISR. Methods: Patients with previous PCI with stenting and who were scheduled for elective PCI after coronary angiogram were recruited from the cardiac catheterization suite over a 12-month period. The angiography report of each patient was perused to identify patients requiring PCI due to ISR. For patients with angiography-confirmed ISR, date of previous PCI to the restenosed stent was noted. CYP2C19*2 genotyping was undertaken using a TaqMan® Drug Metabolism assay. The association between CYP2C19*2 allele carrier status and incidence of coronary ISR within 1 year was assessed using Fisher’s exact test (p < 0.05 significance) and by calculating the odds ratio (OR) with a 95% confidence interval (CI). Results: Of the 82 patients with previous PCI, 29 (35.4%) had angiography-confirmed ISR (12 carriers, 17 noncarriers of CYP2C19*2). In 13 (44.8%) of these patients, the restenosed stent was deployed within 1 year and the patients were on clopidogrel therapy at the time of repeat PCI (8 carriers, 5 non-carriers of CYP2C19*2). The association between CYP2C19*2 allele carrier status and ISR within 1 year was not statistically significant (Fisher’s exact p = 0.067; OR: 4.80, 95% CI: 0.98–23.54, p = 0.053). Conclusions: Despite a higher proportion of CYP2C19*2 allele carriers exhibiting ISR within 1 year compared to non-carriers, the association was not statistically significant. This result may be attributed to the small sample size, and larger prospective studies are recommended to further assess this association.peer-reviewe

Giardia duodenalis assemblages and Entamoeba species infecting non-human primates in an Italian zoological garden: zoonotic potential and management traits

<p>Abstract</p> <p>Background</p> <p><it>Giardia duodenalis </it>and <it>Entamoeba </it>spp. are among the most common intestinal human protozoan parasites worldwide and they are frequently reported in captive non-human primates (NHP). From a public health point of view, infected animals in zoos constitute a risk for animal caretakers and visitors. In this study we carried out the molecular identification of <it>G. duodenalis </it>and <it>Entamoeba </it>spp. from nine species of primates housed in the zoological garden of Rome, to better ascertain their occurrence and zoonotic potential.</p> <p>Results</p> <p><it>G. duodenalis </it>was found only in <it>Lemur catta </it>(47.0%). <it>Entamoeba </it>spp. were detected in all species studied, with the exception of <it>Eulemur macaco </it>and <it>Varecia rubra</it>. The number of positive pools ranged from 5.9% in <it>L. catta </it>to 81.2% in <it>Mandrillus sphinx; </it>in <it>Pan troglodytes </it>the observed prevalence was 53.6%. A mixed <it>Entamoeba</it>-<it>Giardia </it>infection was recorded only in one sample of <it>L. catta</it>. All <it>G. duodenalis </it>isolates belonged to the zoonotic assemblage B, sub assemblage BIV. Three <it>Entamoeba </it>species were identified: <it>E. hartmanni</it>, <it>E. coli </it>and <it>E. dispar</it>.</p> <p>Conclusions</p> <p>Our results highlight the importance of regularly testing animals kept in zoos for the diagnosis of zoonotic parasites, in order to evaluate their pathogenic role in the housed animals and the zoonotic risk linked to their presence. A quick detection of the arrival of pathogens into the enclosures could also be a prerequisite to limit their spread into the structure via the introduction of specific control strategies. The need for molecular identification of some parasite species/genotype in order to better define the zoonotic risk is also highlighted.</p