Heat shock factor 1 mediates the longevity conferred by inhibition of TOR and insulin/IGF-1 signaling pathways in C. elegans

Target of rapamycin (TOR) signaling is an evolutionarily well-conserved pathway that regulates various physiologic processes, including aging and metabolism. One of the key downstream components of TOR signaling is ribosomal protein S6 kinase (S6K) whose inhibition extends the lifespan of yeast, Caenorhabditis elegans, Drosophila, and mice. Here, we demonstrate that the activation of heat shock factor 1 (HSF-1), a crucial longevity transcription factor known to act downstream of the insulin/IGF-1 signaling (IIS) pathway, mediates the prolonged lifespan conferred by mutations in C.elegans S6K (rsks-1). We found that hsf-1 is required for the longevity caused by down-regulation of components in TOR signaling pathways, including TOR and S6K. The induction of a small heat-shock protein hsp-16, a transcriptional target of HSF-1, mediates the long lifespan of rsks-1 mutants. Moreover, we show that synergistic activation of HSF-1 is required for the further enhanced longevity caused by simultaneous down-regulation of TOR and IIS pathways. Our findings suggest that HSF-1 acts as an essential longevity factor that intersects both IIS and TOR signaling pathways.X1144sciescopu

COMPUTER-GENERATED HOLOGRAM ETCHED IN GAAS FOR OPTICAL INTERCONNECTION OF VLSI CIRCUITS

By integrating, on a wafer plane, GaAs semiconductor optoelectronic modulators and detectors with computer-generated holograms between then, the potential for in-plane interconnections is proposed. We report the fabrication and characterisation of a binary-phase relief hologram etched in a GaAs wafer using an averaged Fresnel zone plate design to focus light to 2 x 2 spots for array interconnection. Efficiencies of 28% for this design of binary CGH etched in GaAs have been achieved, close to the theoretical maximum

Effect of groundwater-lake interactions on the distribution of arsenic in a freshwater beach

This thesis presents field measurements and numerical modeling that provide insight into the nearshore geochemical conditions and groundwater flows controlling the mobility of arsenic (As) in a freshwater beach aquifer and its potential discharge to Lake Erie. Field measurements were performed via shore-normal monitoring transects installed at beaches (Little Beach and Main Beach) located adjacent to a brownfield industrial harbour site that has elevated sediment and groundwater As concentrations. Detailed pore water chemistry analyses revealed elevated As (up to 0.056 mg/L) 1 - 2 m below the shoreline at all transect locations. The distributions of species in the aqueous and sedimentary phases suggest that As mobility is strongly linked with iron (Fe) redox cycling. Sediment analysis by sequential extraction revealed a layer of amorphous and crystalline Fe (hydr)oxides present at the sediment-water interface (SWI) near the shoreline. This Fe hydr(oxide) layer may be accumulating As and preventing its release to nearshore waters. Numerical modeling combined with vertical hydraulic gradient measurements indicated that wave-induced recirculation across the aquifer-lake interface was significant and this likely establishes the redox gradient that led to Fe (hydr)oxides precipitation at the SWI. Numerical and field results showed that the water infiltration/exfiltration across the groundwater-lake interface were sensitive to varying wave intensity and seasonal lake water level fluctuations. The source of As in the nearshore beach aquifers remains unknown. While Little Beach is adjacent to the East Headland of the industrial site where elevated As has been recorded, Main Beach is disconnected hydraulically from the East Headland. If the elevated dissolved As observed is from a natural geogenic source, this findings of this thesis may have widespread implications for As cycling in the nearshore areas of the Great Lakes. Finally, while this study focused on As, the nearshore geochemistry and subsurface flows investigated are be pertinent to understanding the discharge of other chemicals (e.g., nitrate, ammonium, phosphorous) to nearshore inland coastal waters via the groundwater pathway

Precise control of phase transformation process in lead zirconate titanate thin films by focused line-beam scanning

Phase transformation and grain growth processes of lead zirconate titanate (PZT) thin films have been precisely controlled by using focused line-beam scanning. The authors promoted the lateral crystallization of PZT grains by controlling a nucleation process and increasing the size of single grains to be as large as 40 μm in length. Focused line-beam scanning allows for the selective growth and crystallization of large PZT grains on predetermined nucleation sites. The high growth rate of the selected PZT grains was attributed to successive suppression of undesirable nucleation except at predetermined positions when pretreated PZT films were exposed to the focused line beam. © 2007 American Institute of Physics

Comparing Computing Platforms for Deep Learning on a Humanoid Robot

The goal of this study is to test two different computing platforms with respect to their suitability for running deep networks as part of a humanoid robot software system. One of the platforms is the CPU-centered Intel NUC7i7BNH and the other is a NVIDIA Jetson TX2 system that puts more emphasis on GPU processing. The experiments addressed a number of benchmarking tasks including pedestrian detection using deep neural networks. Some of the results were unexpected but demonstrate that platforms exhibit both advantages and disadvantages when taking computational performance and electrical power requirements of such a system into account.Comment: 12 pages, 5 figure

Mouse models for human diseases

Mice are increasingly being used as models for the study of various human diseases. This is primarily because among mammalian modals, they are most amenable to genetic manipulations. As we attempt to understand the molecular mechanism of diseases, it is imperative that the genes involved in the disease process be identified. One approach is to study mouse mutants with symptoms analogous to human diseases, and try to identify the genes responsible. Another approach is to manipulate the expression of genes suspected to be involved and see how they affect the disease development. This review briefly discusses the concept of manipulating gene expression by transgenic and gene knockout technology and illustrates this with how these technique are used to study the mechanism of diabetic complications.published_or_final_versio

An interface-proximity model for switchable interfacial uncompensated antiferromagnetic spins and their role in exchange bias

We propose an interface-proximity model that allows us to solve a longstanding puzzle regarding large discrepancies between the experimentally observed and theoretically estimated values of exchange-bias field Heb in coupled ferromagneticantiferromagnetic (FAF) metallic films. In this proposed model, switchable uncompensated (UC) AF spins in contact with an F layer are taken into account as an additionally inserting layer that is chemically or magnetically distinguishable from each of the nominal AF and F layers. Reductions in Heb, enhancements in coercivity, and other exchange-bias behaviors typically observed in experiments are very well reproduced from this model. The switchable interfacial UC region with a sizable thickness, heretofore ignored, plays a crucial role in the exchange bias phenomenon.open6

Atomic-scale depth selectivity of soft x-ray resonant Kerr effect

A study was performed to demonstrate that soft x-ray Kerr rotation, ??K, versus incident grazing angle, ??, and energy, hv, measurements provide an extremely large depth selectivity on the atomic scales even in an ultrathin single layer, simply by choosing appropriate ?? and hv around the resonant regions. Both the experimental and simulation results of ?? vs ??K measurements were considered for depth-varying magnetization reversals in a 3.5-nm-thick Co layer of NiFe/FeMn/Co/Pd films.open161

Soft x-ray resonant magneto-optical Kerr effect as a depth-sensitive probe of magnetic heterogeneity: Its application to resolve helical spin structures using linear p polarization

We have calculated the soft x-ray resonant Kerr intensities as a function of the incident grazing angle of linearly p-polarized waves from the model spin structures, where the chirality (handedness) of the spin spirals (twist in depth) in a magnetic layer and the periodicity of a unit spiral are designed to vary. Variations in the chirality and the periodicity lead to noticeable changes in the Kerr intensity versus the grazing angle, which is due not only to a large sensitivity of the Kerr intensity of the linear p polarization to both the magnitude and direction of the transverse components of magnetizations, but also to a large dependence of the depth sensitivity on the grazing angle at the resonance regions. The measurement and analysis of the specular Kerr intensity are relatively straightforward in determining the inhomogeneous spin structures in depth, compared to those of the Kerr rotation and ellipticity. This is proven to be a convenient and useful probe to determine the handedness of spin spiral structures, as well as to resolve the detailed magnetic heterostructures in depth in ultrathin-layered films.open4