Classical imaging with undetected photons Shapiro, Jeffrey H.; Venkatraman, Dheera; Wong, Franco N. C.
2015 Conference on Lasers and Electro-Optics (CLEO)
Conference Proceeding
We describe a classical-state system capable of mimicking the essential features of Barreto Lemos et a/.'s quantum imaging with undetected photons Nature, 512, 409-412 (2014). but with a much higher ...signal-to-noise ratio.
Using the Landau-Ginzburg-Devonshire approach, we study light-induced phase transitions, evolution of polar state and domain morphology in photo-ferroelectric nanoparticles (NPs). Light exposure ...increases the free carrier density near the NP surface and may in turn induce phase transitions from the nonpolar paraelectric to the polar ferroelectric phase. Using the uniaxial photo-ferroelectric Sn2P2S6 as an example, we show that visible light exposure induces the appearance and vanishing of striped, labyrinthine or curled domains and changes in the polarization switching hysteresis loop shape from paraelectric curves to double, pinched and single loops, as well as the shifting in the position of the tricritical point. Furthermore, we demonstrate that an ensemble of non-interacting photo-ferroelectric NPs may exhibit superparaelectric-like features at the tricritical point, such as strongly frequency-dependent giant piezoelectric and dielectric responses, which can potentially be exploited for piezoelectric applications.
Strontium cerate phosphors doped with rare earths are synthesized through combustion and solid-state reaction in different atmospheres. Phosphors prepared under inert atmosphere exhibited better ...photoluminescence properties. Phosphor prepared through combustion exhibited better luminescence intensity compared to solid-state route. The origin of cerium luminescence in this host is investigated and discussed. Effect of rare earths on luminescence of this phosphor is studied and reported. The abundance of Ce
3+
and Ce
4+
is estimated through spectroscopic measurement.
Mitotic progression requires the activity of the dual specificity phosphatase, cdc25C. Cdc25C function is inhibited by complex formation with two 14-3-3 isoforms, 14-3-3epsilon and 14-3-3gamma. To ...understand the molecular basis of specific complex formation between 14-3-3 proteins and their ligands, chimeric 14-3-3 proteins were tested for their ability to form a complex with cdc25C in vivo. Specific complex formation between cdc25C and 14-3-3epsilon in vivo requires a phenylalanine residue at position 135 (F135) in 14-3-3epsilon. Mutation of this residue to the corresponding residue present in other 14-3-3 isoforms (F135V) leads to reduced binding to cdc25C and a decrease in the ability to inhibit cdc25C function in vivo. Similarly, F135V failed to rescue the incomplete S phase and the G2 DNA damage checkpoint defects observed in cells lacking 14-3-3epsilon. A comparative analysis of the 14-3-3 structures present in the database suggested that the F135 in 14-3-3epsilon was required to maintain the integrity of a pocket that might be involved in secondary interactions with cdc25C. These results suggest that the specificity of the 14-3-3 ligand interaction may be dependent on structural motifs present in the individual 14-3-3 isoforms. PUBLICATION ABSTRACT
Developing the capacity to effectively carry out public health research is an integral part of health systems at both the national and global levels and strengthening research capacity is recognized ...as an approach to better health and development in low- and middle-income countries (LMICs). Especially fields such as sexual and reproductive health (SRH) would require inter-disciplinary teams of researchers equipped with a range of methodologies to achieve this. In November 2013, as part of the International Family Planning Conference in Addis Ababa, Ethiopia, a group of African researchers came together to discuss the gaps and strategies to improve sexual and reproductive health research and research capacity strengthening in Africa. This commentary summarizes the three broad areas where the issues and proposed solutions have concentrated around: 1) Addressing research gaps that are most relevant to policies and programmes in SRH, 2) Carrying out high quality and collaborative research, and 3) Translating research findings into SRH policies and programmes. Even though the focus of the discussions was Africa, the issues and proposed solutions can also be applied to other regions facing a high burden of disease with limited resources. The time is now and these can be achieved through synergistic commitment of African and global researchers, funders and organizations.
The paper investigates the techniques of quantum computation in metrological predictions, with a particular emphasis on enhancing prediction potential through variational parameter estimation. The ...applicability of quantum simulations and quantum metrology techniques for modelling complex physical systems and achieving high-resolution measurements are proposed. The impacts of various parameter distributions and learning rates on predictive accuracy are investigated. Modelling the time evolution of physical systems Hamiltonian simulation and the product formula procedure are adopted. The time block method is analyzed in order to reduce simulation errors, while the Schatten-infinite norm is used to evaluate the simulation precision. Methodology requires estimation of optimized parameters by minimizing loss functions and resource needs. For this purpose, the mathematical formulations of Cramer Rao Bound and Fischer Information are indispensable requirements. The impact of learning rates on regulating the loss function for various parameter values. Using parameterized quantum circuits, the article outlines a four-step procedure for extracting information. This method involves the preparation of input states, the evolution of parameterized quantum states, the measurement of outputs, and the estimation of parameters based on multiple measurements. The study analyses variational unitary circuits with optimized parameter estimation for more precise predictions. The findings shed light on the effects of normal parameter distributions and learning rates on attaining the most optimal state and comparison with classical Long Short Term Memory (LSTM) predictions, providing valuable insights for the development of more appropriate approaches in quantum computing.
- Powered Two Wheelers (PTW) are very sensitive to environmental conditions and advancement in two-wheeler safety has not kept pace with the advancement in two-wheelers. The objective of our research ...is to bring about an improved design for powered two wheelers, analyzing the changes through simulation and thereby improving the safety considerations. According to the databases referred regarding accidents in depth study, it is observed that two-wheelers top the chart in number of accidents by a big margin and these accidents causes more fatal injuries. To save the rider, this paper proposes to constraint the rider along with pillion to the vehicle using “Leg holding device“ and seat belt. Side airbags are employed to absorb the impact of accident. The present safety system saves the rider in frontal collisions, while this research also focuses on side collisions. ISO 13232 standard accident scenarios were followed. For simulation of scenarios multi body dynamics software called RecurDyn is used. The improvement in employing safety measures is compared with its absence and results are plotted.
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