Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system1. Most of these diseases, including Alzheimer's, Parkinson's and Huntington's disease are characterized by age-dependent deterioration in learning and memory functions and movement coordination2. Here we use behavioral assays, including the negative geotaxis assay3 and the aversive phototaxic suppression assay (APS assay)4,5, to show that some of the behavior characteristics associated with human neurodegeneration can be recapitulated in flies. In the negative geotaxis assay, the natural tendency of flies to move against gravity when agitated is utilized to study genes or conditions that may hinder locomotor capacities. In the APS assay, the learning and memory functions are tested in positively-phototactic flies trained to associate light with aversive bitter taste and hence avoid this otherwise natural tendency to move toward light. Testing these trained flies 6 hours post-training is used to assess memory functions. Using these assays, the contribution of any genetic or environmental factors toward developing neurodegeneration can be easily studied in flies

Bis[2-(4-benzo­yloxy-2-hy­droxy­benzo­yl)-1-phenyl­ethenolato]diethano­lzinc(II)

The mononuclear title complex, [Zn(C22H15O5)2(C2H5OH)2], contains a ZnII atom (site symmetry ) surrounded by six O atoms of the keto groups of two substituted 1,3-diketonate ligands and of two ethanol mol­ecules, resulting in a distorted octa­hedral coordination environment. The mol­ecular configuration is stabilized by an intra­molecular hydrogen bond between the phenolic hy­droxy group and the adjacent keto group. The hy­droxy group acts likewise as an acceptor of an inter­molecular O—H⋯O hydrogen bond with the hy­droxy group of the ethanol mol­ecule as the donor. The hydrogen-bonding scheme leads to the formation of supra­molecular layers parallel to (010)

Silicon nitride metalenses for unpolarized high-NA visible imaging

As one of nanoscale planar structures, metasurface has shown excellent superiorities on manipulating light intensity, phase and/or polarization with specially designed nanoposts pattern. It allows to miniature a bulky optical lens into the chip-size metalens with wavelength-order thickness, playing an unprecedented role in visible imaging systems (e.g. ultrawide-angle lens and telephoto). However, a CMOS-compatible metalens has yet to be achieved in the visible region due to the limitation on material properties such as transmission and compatibility. Here, we experimentally demonstrate a divergent metalens based on silicon nitride platform with large numerical aperture (NA~0.98) and high transmission (~0.8) for unpolarized visible light, fabricated by a 695-nm-thick hexagonal silicon nitride array with a minimum space of 42 nm between adjacent nanoposts. Nearly diffraction-limit virtual focus spots are achieved within the visible region. Such metalens enables to shrink objects into a micro-scale size field of view as small as a single-mode fiber core. Furthermore, a macroscopic metalens with 1-cm-diameter is also realized including over half billion nanoposts, showing a potential application of wide viewing-angle functionality. Thanks to the high-transmission and CMOS-compatibility of silicon nitride, our findings may open a new door for the miniaturization of optical lenses in the fields of optical fibers, microendoscopes, smart phones, aerial cameras, beam shaping, and other integrated on-chip devices.Comment: 16 pages, 7 figure

The geodesic form of light-ray trace in the inhomogeneous media

The canonical equations of the optical cloaking proposed by Shurig, Pendry and Smith has been proved to be equivalent to the geodesic in a 3-dimensional curved space. Carrying out the argument we extend to the 4-dimensional Riemannian space where the extra time item appears as the potential term in the canonical equations. The physical meaning of the results is interpreted.Comment: 15 pages, 6 figure

Water Resources Contribution To Economic Growth In Erdos City: Model And Demonstration

Erdos City has been one of the fastest growing economic regions in China in the past twenty years, whose average annual economic growth rate has exceeded 20%. However, water resources shortage is becoming increasingly significant in constraint on social development and has gradually developed to be one of primary weakest factors. Based on the analysis of main factors promoting economic growth in Erdos City with Cobb-Douglas production function in economics, the economic growth model involving water resources availability and coal output has been established and the data conversion method considering water consumption efficiency and water consumption structural change has been proposed. In this way, it has made up for the deficiency of failing to fully consider the contribution of water consumption efficiency improvement and water consumption structural change to economic growth in the past researches. What have been discovered in the simulation and analysis of water resources contribution to economic growth in Erdos City from 1980 to 2010 as follows: (1) Water resources average contribution rate to economic growth in Erdos City in the past 30 years is 8.26%; (2) Consumption efficiency and structural change of water resources have played an important role in promoting economic development; (3) Water resources contribution to economic growth has shown a gradually increasing trend that the average contribution rates in the three decades are 1.87%, 9.69% and 10.09% respectively. The trend is closely connected with constantly increased gross water consumption, obvious improvement of water consumption efficiency and gradual upgrading of water consumption structure in the local area. It also has reflected that water resources have played an increasingly significant role in constraint on regional economic social development

High-performance non-Fermi-liquid metallic thermoelectric materials

Searching for high-performance thermoelectric (TE) materials in the paradigm of narrow-bandgap semiconductors has lasted for nearly 70 years and is obviously hampered by a bottleneck of research now. Here we report on the discovery of a few metallic compounds, TiFexCu2x-1Sb and TiFe1.33Sb, showing the thermopower exceeding many TE semiconductors and the dimensionless figure of merits comparable with the state-of-the-art TE materials. A quasi-linear temperature (T) dependence of electrical resistivity in 2 K - 700 K and the logarithmic T-dependent electronic specific heat at low temperature are also observed to coexist with the high thermopower, highlighting the strong intercoupling of the non-Fermi-liquid (NFL) quantum critical behavior of electrons with TE transports. Electronic structure analysis reveals the existence of fluctuating Fe-eg-related local magnetic moments, Fe-Fe antiferromagnetic (AFM) interaction at the nearest 4c-4d sites, and two-fold degenerate eg orbitals antiferromagnetically coupled with the dual-type itinerant electrons close to the Fermi level, all of which infer to a competition between the AFM ordering and Kondo-like spin compensation as well as a parallel two-channel Kondo effect. These effects are both strongly meditated by the structural disorder due to the random filling of Fe/Cu at the equivalent 4c/4d sites of the Heusler crystal lattice. The magnetic susceptibility deviates from ideal antiferromagnetism but can be fitted well by x(T) = 1/({\theta} + BT{\alpha}), seemingly being consistent with the quantum critical scenario of strong local correlation as discussed before. Our work not only breaks the dilemma that the promising TE materials should be heavily-doped semiconductors, but also demonstrates the correlation among high TE performance, NFL quantum criticality, and magnetic fluctuation, which opens up new directions for future research.Comment: 19 pages with 6 figure