The hydrodynamic quantification of superhydrophobic slipperiness has traditionally employed two canonical problems – namely, shear flow about a single surface and pressure-driven channel flow. We here advocate the use of a new class of canonical problems, defined by the motion of a superhydrophobic particle through an otherwise quiescent liquid. In these problems the superhydrophobic effect is naturally measured by the enhancement of the Stokes mobility relative to the corresponding mobility of a homogeneous particle. We focus upon what may be the simplest problem in that class – the rotation of an infinite circular cylinder whose boundary is periodically decorated by a finite number of infinite grooves – with the goal of calculating the rotational mobility (velocity-to-torque ratio). The associated two-dimensional flow problem is defined by two geometric parameters – namely, the number $N$ of grooves and the solid fraction $\unicode[STIX]{x1D719}$. Using matched asymptotic expansions we analyse the large-$N$ limit, seeking the mobility enhancement from the respective homogeneous-cylinder mobility value. We thus find the two-term approximation,

$$\begin{eqnarray}\displaystyle 1+{\displaystyle \frac{2}{N}}\ln \csc {\displaystyle \frac{\unicode[STIX]{x03C0}\unicode[STIX]{x1D719}}{2}}, & & \displaystyle \nonumber\end{eqnarray}$$

$N=1,2,4,8,\ldots$

$N$

This article examines how public health addresses alcohol use through marketing — place, product, promotion, and price. The article reviews current product trends and how restrictions on certain products designs may reduce youth consumption; how product availability may be restricted through zoning; and the current advertising landscape.

In this study, we have successfully grown hBN/graphene heterostructures on copper thin films using chemical vapor deposition in a single process. The first and most surprising result is that graphene grows underneath hBN and adjacent to the Cu film even though it is deposited second. This was determined from cross-sectional TEM analysis and XPS depth profiling, which chemically identified the relative positions of hBN and graphene. The effect of various growth conditions on graphene/hBN heterostructures was also studied. It was found that a pressure of 200 torr and a hydrogen flow rate of 200 sccm (∼1 H2/N2) yielded the highest quality of graphene, with full surface coverage occurring after a growth time of 120 min. The resulting graphene films were found to be approximately 6–8 layers thick. The grain size of the nanocrystalline graphene was found to be 15–50 nm varying based on growth conditions.

A well-posedness theory for the initial-value problem for hydroelastic waves in two spatial dimensions is presented. This problem, which arises in numerous applications, describes the evolution of a thin elastic membrane in a two-dimensional (2D) potential flow. We use a model for the elastic sheet that accounts for bending stresses and membrane tension, but which neglects the mass of the membrane. The analysis is based on a vortex sheet formulation and, following earlier analyses and numerical computations in 2D interfacial flow with surface tension, we use an angle–arclength representation of the problem. We prove short-time well-posedness in Sobolev spaces. The proof is based on energy estimates, and the main challenge is to find a definition of the energy and estimates on high-order non-local terms so that an a priori bound can be obtained.

AlGaN/GaN heterostructures were grown by metal–organic chemical vapor deposition (MOCVD) on sp2-bonded BN using AlN as a nucleation layer. The best x-ray diffraction rocking curve full-width-at-half-maximums (FWHMs) are 0.13° and 0.17° for the GaN (0002) and ( $10\bar 12$ ) diffraction peaks. Hall-effect measurements show room temperature mobility near 2000 cm/V·s with sheet carrier density of ∼1 × 1013 cm−2, comparable to the best values obtained on sapphire using Fe-doped GaN buffers. The best low temperature mobility of the 2-dimensional electron gas (2DEG) is ∼33,000 cm2/V·s; indicating that the dominant scattering mechanism limiting the transport of 2DEG is interface roughness. Good quality BN grown directly onto sapphire is shown to be effective for reducing parallel conduction that exists due to residual donor impurities in the buffer. Luminescence measurements indicate good optical quality of the GaN/BN/sapphire. The residual strain in the GaN layer is found to be almost completely eliminated when it is released from the substrate.

Resonant optical rod antennas are made from aluminum using electron-beam lithography and are optically characterized by linear dark-field microscopy and nonlinear multi-photon luminescence spectroscopy. It is demonstrated that by exciting close to the interband transition of aluminum at about 1.5 eV different radiative decay channels can be addressed. Over a period of weeks, a slight spectral red-shift and a decrease in the scattering intensity are observed due to the formation of a native oxide layer at the metal-air interface. To investigate the concurrent influence of shape transformation and dielectric environment on the spectral response function we carry out numerical calculations using finite difference time domain (FDTD) methods. It is found that the induced energy shift is mainly determined by the change of the dielectric constant in the nanovicinity resulting in an overall red-shift as seen in the experiment. These findings allow for a better understanding of designing and modeling plasmonic aluminum nanostructures for e.g. UV sensing where the shift in peak resonance and linewidth are key observables.

Vitamin D and folate are associated with decreased colorectal cancer risk and their association with colorectal cancer prognosis is under investigation. We assessed the levels of plasma 25-hydroxyvitamin D3 (25(OH)D3), folate and vitamin B12 in an international pilot study in order to determine variability of these biomarkers based on geographical location. Plasma 25(OH)D3, folate and vitamin B12 concentrations were measured in 149 invasive, newly diagnosed colorectal cancer cases from Heidelberg (Germany), Seattle (WA, USA), and Tampa (FL, USA) and in ninety-one age- and sex-matched controls. Their associations with potential predictors were assessed using multivariate linear regression analyses. Plasma 25(OH)D3, folate and vitamin B12 concentrations differed by location. Other predictors were season for 25(OH)D3 and tumour stage (vitamin B12). Season-corrected average 25(OH)D3 concentrations were higher in Heidelberg (31·7 ng/ml; range 11·0–83·0 ng/ml) than in Seattle (23·3 ng/ml; range 4·0–80·0 ng/ml) and Tampa (21·1 ng/ml; range 4·6–51·6 ng/ml). In Heidelberg, a strong seasonal variation was observed. Folate (11·1 ng/ml) and vitamin B12 (395 pg/ml) concentrations in Heidelberg were lower than those in Seattle (25·3 ng/ml and 740 pg/ml, respectively) and Tampa (23·8 ng/ml and 522 pg/ml, respectively). Differences in plasma 25(OH)D3 and folate concentrations between Heidelberg and the US sites were observed, probably reflecting variation in outdoor activities and sun-avoidance behaviour during summer as well as in folic acid fortification and supplement use. Intra-site differences at each study location were greater than between-location variability, suggesting that individual health behaviours play a significant role. Nevertheless, the intra-site differences we observed may be due to chance because of the limited sample size. Our pilot study illustrates the value of an international cohort in studying colorectal cancer prognosis to discern geographical differences in a broad range of exposures.

African trypanosomes have emerged as promising unicellular model organisms for the next generation of systems biology. They offer unique advantages, due to their relative simplicity, the availability of all standard genomics techniques and a long history of quantitative research. Reproducible cultivation methods exist for morphologically and physiologically distinct life-cycle stages. The genome has been sequenced, and microarrays, RNA-interference and high-accuracy metabolomics are available. Furthermore, the availability of extensive kinetic data on all glycolytic enzymes has led to the early development of a complete, experiment-based dynamic model of an important biochemical pathway. Here we describe the achievements of trypanosome systems biology so far and outline the necessary steps towards the ambitious aim of creating a ‘Silicon Trypanosome’, a comprehensive, experiment-based, multi-scale mathematical model of trypanosome physiology. We expect that, in the long run, the quantitative modelling enabled by the Silicon Trypanosome will play a key role in selecting the most suitable targets for developing new anti-parasite drugs.

Current synthetic techniques to high-quality quantum dots (“QD's”) involve organometallic precursors that are hazardous and expensive and require they be rapidly injected into an extremely hot solvent to form the QD's. A new method for synthesizing high-quality CdSe QD's while circumventing these problems has been developed. Different cadmium salts were studied as Cd precursors alternative to dimethylcadmium. High-quality CdSe QD's were found possible with cadmium acetate as the Cd precursor. Changes in solvent temperature and reaction time had a systematic effect on QD particle sizes and the accompanying optical properties. These preliminary results point to a general method for producing high-quality QD's that is safer and much more versatile.

It is currently thought that New World monkeys, prosimians, and humans are the only primates to possess vomeronasal organs (VNOs) as adults. Recent studies of the human VNO suggest that previous investigations on Old World primates may have missed the VNO. We examined nasal septa from the chimpanzee (Pan troglodytes) grossly and histologically for comparison with nasal septa from humans, Old World monkeys (Macaca fascicularis, M. nemistrina) and prosimian primates (Microcebus murinus, Otolemur garnettii). Grossly, chimpanzees had depressions on the nasal septum similar to fossae reported anterior to the VNO openings in humans. Histologically, chimpanzees and humans had bilateral epithelial tubes which were above the superior margin of the paraseptal cartilages (vomeronasal cartilage homologue). The epithelial tubes had a homogeneous ciliated epithelium. These structures were thus positionally and structurally identical to the human VNO and unlike the well-developed prosimian VNOs which were surrounded by vomeronasal cartilage. Macaques had no structures which resembled the VNO of either the prosimians or humans. The results demonstrate that the VNO is present postnatally in the chimpanzee and is almost identical to the human VNO in its anatomical position and histological structure. This in turn suggests that the reported absence of the VNO in at least some adult Old World primates is artifactual, and that further study may provide evidence for its existence in other species.

The catalytic oxidation of methane was studied over palladium supported on nanocrystalline ceria. Three palladium weight loadings (1, 5, and 10 wt%) were tested after calcining at 500 °C, at 280 °C and after no calcination at all. For the 5 and 10 wt% loadings, the 280 °C-calcined and non-calcined catalysts exhibit enhanced activity after several heating and cooling cycles. Calcining these same catalysts at 500 °C results in a systematic decline in activity. For all pretreatments the 1 wt% Pd catalyst exhibits decreasing activity. For the 5 and 10 wt% Pd loadings, the non-calcined catalysts are more active than the 280 °C-calcined catalysts, which are more active than the 500 °C-calcined catalysts. For the 1 wt% Pd catalyst, the opposite is true. The catalyst activity improves as the Pd loading is increased.