(E)-2-(2,4-Dihydroxy­benzyl­ideneamino)benzonitrile

The mol­ecule of the title compound, C14H10N2O2, adopts the phenol–imine tautomeric form. The dihedral angle between the planes of the two benzene rings is 13.84 (13)°. A strong intra­molecular O—H⋯N hydrogen-bonding inter­action stabilizes the mol­ecular conformation. In the crystal structure, centrosymmetrically related mol­ecules are linked into dimers by inter­molecular C—H⋯O and O—H⋯N hydrogen bonds

Evolutionary dynamics on any population structure

Evolution occurs in populations of reproducing individuals. The structure of a biological population affects which traits evolve. Understanding evolutionary game dynamics in structured populations is difficult. Precise results have been absent for a long time, but have recently emerged for special structures where all individuals have the same number of neighbors. But the problem of determining which trait is favored by selection in the natural case where the number of neighbors can vary, has remained open. For arbitrary selection intensity, the problem is in a computational complexity class which suggests there is no efficient algorithm. Whether there exists a simple solution for weak selection was unanswered. Here we provide, surprisingly, a general formula for weak selection that applies to any graph or social network. Our method uses coalescent theory and relies on calculating the meeting times of random walks. We can now evaluate large numbers of diverse and heterogeneous population structures for their propensity to favor cooperation. We can also study how small changes in population structure---graph surgery---affect evolutionary outcomes. We find that cooperation flourishes most in societies that are based on strong pairwise ties.Comment: 68 pages, 10 figure

2-p-Tolyl-1-p-tolyl­methyl-1H-benzimidazole

The asymmetric unit of the title compound, C22H20N2, contains two crystallographically independent mol­ecules in which the planar benzimidazole ring systems are oriented with respect to the adjacent tolyl rings at dihedral angles of 47.08 (8)/76.85 (8) and 39.52 (9)/87.49 (9)°, while the dihedral angles between the tolyl rings are 73.99 (3) and 81.51 (9)°. In the crystal structure, pairs of inter­molecular C—H⋯N inter­actions link one of the asymmetric mol­ecules into centrosymmetric dimers through R 2 2(8) ring motifs

Simulation studies of a phenomenological model for elongated virus capsid formation

We study a phenomenological model in which the simulated packing of hard, attractive spheres on a prolate spheroid surface with convexity constraints produces structures identical to those of prolate virus capsid structures. Our simulation approach combines the traditional Monte Carlo method with a modified method of random sampling on an ellipsoidal surface and a convex hull searching algorithm. Using this approach we identify the minimum physical requirements for non-icosahedral, elongated virus capsids, such as two aberrant flock house virus (FHV) particles and the prolate prohead of bacteriophage $\phi_{29}$, and discuss the implication of our simulation results in the context of recent experimental findings. Our predicted structures may also be experimentally realized by evaporation-driven assembly of colloidal spheres

4,4′-(1,3,4-Oxadiazole-2,5-diyl)di­pyri­dinium dibromide monohydrate

In the title compound, C12H10N4O+·2Br−·H2O, the cation is approximately planar: the terminal rings make a dihedral angle of 7.91 (6)° with each other and dihedral angles of 6.02 (1) and 6.50 (8)° with the central ring. It is linked to the bromide anions and water mol­ecules by N—H⋯Br hydrogen bonds. In addition, O—H⋯Br and N—H⋯Br hydrogen bonds link these units into a three-dimensional network. C—H⋯N, C—H⋯Br and N—H⋯O inter­actions are also observed

Cryogenic Detector Technology for Space Science Application

We review the current status of detector development at NASA's Goddard Space Flight Center and address future prospect for space science application. In particular, the IR detector capability and applicability to second generation SOFIA instrument will be discussed. We will examine areas such as 3-dimensional hybridization of large format bolometer arrays to readout multiplexers; advanced light coupling scheme for planar ortho-mode transducer circuitry; integration of high density readout wiring for low temperature detector arrays; and microwave multiplexers for large format superconducting detector arrays

Effect of high-vacuum setting on phacoemulsification efficiency

Purpose To evaluate the effect of a high-vacuum setting versus a low-vacuum setting on the efficiency of phacoemulsification. Setting Sunderland Eye Infirmary, Sunderland, United Kingdom. Design Prospective clinical trial. Methods Consecutive patients having cataract surgery in 2014 were recruited. Cataract surgery was performed by 2 experienced surgeons using a phacoemulsification machine with monitored forced infusion. The cataractous lens was split into 2 heminuclei using the stop-and-chop technique; in 1 heminucleus, phacoemulsification and aspiration used a high-vacuum setting (600 mm Hg; treatment group) and in the other heminucleus, a low-vacuum setting (350 mm Hg; control group). The high and low settings were alternated by case per the operating list to reduce surgeon bias. The main outcome measures were cumulative dissipated energy (CDE) and active heminucleus removal time. Results One hundred sixty patients (160 eyes) were enrolled in the study, and 158 were included in the analysis. The CDE per heminucleus was significantly lower with the high-vacuum setting than with the low-vacuum setting (mean 2.81 percent-seconds; 95% confidence interval (CI), 2.44-3.21 versus 3.81 percent-seconds; 95% CI, 3.38-4.20; P < .001). The active heminucleus removal time was significantly shorter in the high-vacuum group than the low-vacuum group (mean 27.77 seconds; 95% CI, 25.26-30.19 versus 33.59 seconds; 95% CI, 31.07-35.92; P < .001). The observed differences were independent of the surgeon, patient age and sex, incision size, and nucleus density. No intraoperative complications were observed in either group. Conclusion A high-vacuum setting improved phacoemulsification efficiency using an active fluidics system and torsional phacoemulsificatio