Contrast‐enhanced wide‐angle high‐speed polarization modulator for active‐retarder 3‐D displays

Abstract— A contrast‐enhanced wide‐angle high‐speed polarization modulator for active‐retarder 3‐D displays is proposed. By using a double liquid‐crystal‐cell structure together with a dedicated driving scheme and an external quarter‐wave retarder, a high‐performance modulator can be realized, resulting in minimized brightness loss and low cross‐talk levels in fast‐refresh time‐multiplexed 3‐D displays.     

GCase and LIMP2 Abnormalities in the Liver of Niemann Pick Type C Mice

The lysosomal storage disease Niemann–Pick type C (NPC) is caused by impaired cholesterol efflux from lysosomes, which is accompanied by secondary lysosomal accumulation of sphingomyelin and glucosylceramide (GlcCer). Similar to Gaucher disease (GD), patients deficient in glucocerebrosidase (GCase) degrading GlcCer, NPC patients show an elevated glucosylsphingosine and glucosylated cholesterol. In livers of mice lacking the lysosomal cholesterol efflux transporter NPC1, we investigated the expression of established biomarkers of lipid-laden macrophages of GD patients, their GCase status, and content on the cytosol facing glucosylceramidase GBA2 and lysosomal integral membrane protein type B (LIMP2), a transporter of newly formed GCase to lysosomes. Livers of 80-week-old Npc1^−/− mice showed a partially reduced GCase protein and enzymatic activity. In contrast, GBA2 levels tended to be reciprocally increased with the GCase deficiency. In Npc1^−/− liver, increased expression of lysosomal enzymes (cathepsin D, acid ceramidase) was observed as well as increased markers of lipid-stressed macrophages (GPNMB and galectin-3). Immunohistochemistry showed that the latter markers are expressed by lipid laden Kupffer cells. Earlier reported increase of LIMP2 in Npc1^−/− liver was confirmed. Unexpectedly, immunohistochemistry showed that LIMP2 is particularly overexpressed in the hepatocytes of the Npc1^−/− liver. LIMP2 in these hepatocytes seems not to only localize to (endo)lysosomes. The recent recognition that LIMP2 harbors a cholesterol channel prompts the speculation that LIMP2 in Npc1^−/− hepatocytes might mediate export of cholesterol into the bile and thus protects the hepatocytes.     

Effect of high temperature heat treatment on intergranular corrosion of AlMgSi(Cu) model alloy

Copper containing 6000-series aluminium alloys may become susceptible to intergranular corrosion (IGC) as a result of improper thermomechanical processing. Effect of cooling rate after solution heat treatment on the corrosion behaviour of a model AlMgSi(Cu) alloy of nominal composition (wt%) 0.6 Mg, 0.6 Si, 0.2 Fe, 0.2 Mn and 0.1 Cu was investigated. Slow cooling rates were simulated by isothermal treatment for predetermined times in lower temperature baths immediately after solution heat treatment. Treatment for 10-100 s at temperatures below 400 °C introduced susceptibility to IGC. Longer heat treatment at the same temperatures introduced susceptibility to pitting. A corrosion resistant time zone was found between the zones of IGC and pitting at temperatures lower than 350 °C. Quenching in water after solution heat treatment prevented IGC. IGC was related to microgalvanic coupling between the noble Q-phase (Al₄Mg₈Si₇Cu₂) grain boundary precipitates and the adjacent depleted zone. Pitting was attributed to coarse particles in the matrix. Possible mechanisms causing the corrosion resistant intermediate zone are discussed. The results indicate possible methods for obtaining increased corrosion resistance of similar alloys by proper thermal processing.     

Biomimetic Polymer Nanostructures by Injection Molding

The nanometer scale topography of self‐assembling structural protein complexes in animals is believed to induce favorable cell responses. An important example of such nanostructured biological complexes is fibrillar collagen that possesses a cross‐striation structure with a periodicity of 69 nm and a peak‐to‐valley distance of 4–6 nm. Bovine collagen type I was assembled into fibrillar structures in vitro and sedimented onto solid supports. Their structural motif was transferred into a nickel replica by physical vapor deposition of a small‐grained metal layer followed by galvanic plating. The resulting inverted nickel structure was found to faithfully present most of the micrometer and nanometer scale topography of the biological original. This nickel replica was used as a die for the injection molding of a range of different thermoplastic polymers. Total injection molding cycle times were in the range of 30–45 seconds. One of the polymer materials investigated, polyethylene, displayed poor replication of the biological nanotopographical motif. However, the majority of the polymers showed very high replication fidelity as witnessed by their ability to replicate the cross‐striation features of less than 5 nm height difference. The latter group of materials includes poly(propylene), poly(methyl methacrylate), poly(L ‐lactic acid), polycaprolactone, and a copolymer of cyclic and linear olefins (COC). This work suggests that the current limiting factor for the injection molding of nanometer scale topography in thermoplastic polymers lies with the grain size of the initial metal coating of the mold rather than the polymers themselves.

     

Inclusion/Exclusion Meets Measure and Conquer

Inclusion/exclusion and measure and conquer are two central techniques from the field of exact exponential-time algorithms that recently received a lot of attention. In this paper, we show that both techniques can be used in a single algorithm. This is done by looking at the principle of inclusion/exclusion as a branching rule. This inclusion/exclusion-based branching rule can be combined in a branch-and-reduce algorithm with traditional branching rules and reduction rules. The resulting algorithms can be analysed using measure and conquer allowing us to obtain good upper bounds on their running times. In this way, we obtain the currently fastest exact exponential-time algorithms for a number of domination problems in graphs. Among these are faster polynomial-space and exponential-space algorithms for #Dominating Set and Minimum Weight Dominating Set (for the case where the set of possible weight sums is polynomially bounded), and a faster polynomial-space algorithm for Domatic Number. This approach is also extended in this paper to the setting where not all requirements in a problem need to be satisfied. This results in faster polynomial-space and exponential-space algorithms for Partial Dominating Set, and faster polynomial-space and exponential-space algorithms for the well-studied parameterised problem k-Set Splitting and its generalisation k-Not-All-Equal Satisfiability.     

Effect of artificial aging on intergranular corrosion of extruded AlMgSi alloy with small Cu content

The effect of artificial aging parameters on the corrosion performance of air cooled AlMgSi(Cu) model alloy extrusions was investigated. Accelerated corrosion test revealed that the extrusions were highly susceptible to intergranular corrosion (IGC) in the naturally aged condition. However, IGC susceptibility was reduced, and finally eliminated, by artificial aging. Overaging introduced slight pitting susceptibility. EDS X-ray mapping in FE-TEM revealed Mg₂Si and Q-phase (Al₄Cu₂Mg₈Si₇) grain boundary precipitates and a continuous Cu-enriched grain boundary film. IGC susceptibility was related to the Cu-enriched grain boundary film. Increased IGC resistance was caused by coarsening of the grain boundary film by aging. Pitting susceptibility by over aging evolved due to coarsening of the Q-phase particles in the grain bodies.     

(Approximate) Uncertain Skylines

Given a set of points with uncertain locations, we consider the problem of computing the probability of each point lying on the skyline, that is, the probability that it is not dominated by any other input point. If each point’s uncertainty is described as a probability distribution over a discrete set of locations, we improve the best known exact solution. We also suggest why we believe our solution might be optimal. Next, we describe simple, near-linear time approximation algorithms for computing the probability of each point lying on the skyline. In addition, some of our methods can be adapted to construct data structures that can efficiently determine the probability of a query point lying on the skyline.     

Little effect of transfer technique instruction and physical fitness training in reducing low back pain among nurses: a cluster randomised intervention study

The aim of this study was to evaluate the effect of a transfer technique education programme (TT) alone or in combination with physical fitness training (TTPT) compared with a control group, who followed their usual routine. Eleven clinical hospital wards were cluster randomised to either intervention (six wards) or to control (five wards). The intervention cluster was individually randomised to TT (55 nurses) and TTPT (50 nurses), control (76 nurses). The transfer technique programme was a 4-d course of train-the-trainers to teach transfer technique to their colleagues. The physical training consisted of supervised physical fitness training 1 h twice per week for 8 weeks. Implementing transfer technique alone or in combination with physical fitness training among a hospital nursing staff did not, when compared to a control group, show any statistical differences according to self-reported low back pain (LBP), pain level, disability and sick leave at a 12-month follow-up. However, the individual randomised intervention subgroup (transfer technique/physical training) significantly improved the LBP-disability (p = 0.001). Although weakened by a high withdrawal rate, teaching transfer technique to nurses in a hospital setting needs to be thoroughly considered. Other priorities such as physical training may be taken into consideration. The current study supports the findings of other studies that introducing transfer technique alone has no effect in targeting LBP. However, physical training seems to have an influence in minimising the LBP consequences and may be important in the discussion of how to prevent LBP or the recurrence of LBP among nursing personnel.