93 research outputs found
Partially Coherent Vortex Beam: From Theory to Experiment
Partially coherent vortex beam exhibits some unique and interesting properties, for example, correlation singularities (i.e., ring dislocations) exist in its correlation function, and one can determine the magnitude of the topological charge of the vortex phase from the number of the ring dislocations. Modulating the coherence of a vortex beam provides a convenient way for shaping its focused beam spot, which is useful for material processing and optical trapping. Furthermore, a partially coherent vortex beam has an advantage over a partially coherent beam without vortex phase for reducing turbulence‐induced scintillation, which will be useful in free‐space optical communications. We introduce recent theoretical and experimental developments on partially coherent vortex beams
A Stackelberg Solution to Joint Optimization Problems: A Case Study of Green Design
AbstractDesign of complex engineered systems often involves optimization of multiple competing problems that are supposed to compromise to arrive at equilibrium optima, entailing a joint optimization problem. This paper reveals the leader-follower decision structure inherent in joint optimization problems. A Stackelberg game solution is formulated to model a leader-follower joint optimization problem as a two-level optimization problem between two decision makers, implicating a mathematical program that contains sub-optimization problems as its constraints. A case study of coffee grinder green design demonstrates the potential of Stackelberg solution to joint optimization of modularity subject with conflicting goals
Axial correlation revivals and number factorization with structured random waves
We advance a general theory of field correlation revivals of structured
random wave packets, composed of superpositions of propagation-invariant modes,
at pairs of planes transverse to the packet propagation direction. We derive an
elegant analytical relation between the normalized intensity autocorrelation
function of thus structured paraxial light fields at a pair of points on an
optical axis of the system and a Gauss sum, thereby establishing a fundamental
link between statistical optics and number theory. We propose and
experimentally implement a simple, robust analog random wave computer that can
efficiently decompose numbers into prime factors
Incoherent mode division multiplexing for high-security information encryption
In the age of information explosion, the conventional optical communication
protocols are rapidly reaching the limits of their capacity, as almost all
available degrees of freedom (e.g., wavelength, polarization) for division
multiplexing have been explored to date. Recent advances in coherent mode
division multiplexing have greatly facilitated high-speed optical
communications and secure, high-capacity information storage and transfer.
However, coherent mode division multiplexing is quite vulnerable to even minute
environmental disturbances which can cause significant information loss. Here,
we propose and experimentally demonstrate a paradigm shift to incoherent mode
division multiplexing for high-security optical information encryption by
harnessing the degree of coherence of structured random light beams. In
contrast to the conventional techniques, our approach does not require mode
orthogonality to circumnavigate unwanted mode crosstalk. In addition, our
protocol has, in principle, no upper bound on its capacity. Thanks to the
extreme robustness of structured random light to external perturbations, we are
able to achieve highly accurate information encryption and decryption in the
adverse environment. The proposed protocol opens new horizons in an array of
fields, such as optical communications and cryptography, and it can be relevant
for information processing with acoustical, matter as well as other types of
waves.Comment: 23 pages, 6 figure
A rare novel mutation in TECTA causes autosomal dominant nonsyndromic hearing loss in a Mongolian family
BACKGROUND: The genetic basis of autosomal dominant nonsyndromic hearing loss is complex. Genetic factors are responsible for approximately 50% of cases with congenital hearing loss. However, no previous studies have documented the clinical phenotype and genetic basis of autosomal dominant nonsyndromic hearing loss in Mongolians. METHODS: In this study, we performed exon capture sequencing of a Mongolian family with hereditary hearing loss and identified a novel mutation in TECTA gene, which encodes α -tectorin, a major component of the inner ear extracellular matrix that contacts the specialized sensory hair cells. RESULTS: The novel G → T missense mutation at nucleotide 6016 results in a substitution of amino acid aspartate at 2006 with tyrosine (Asp2006Tyr) in a highly conserved zona pellucida (ZP) domain of α-tectorin. The mutation is not found in control subjects from the same family with normal hearing and a genotype-phenotype correlation is observed. CONCLUSION: A novel missense mutation c.6016 G > T (p.Asp2006Tyr) of TECTA gene is a characteristic TECTA-related mutation which causes autosomal dominant nonsyndromic hearing loss. Our result indicated that mutation in TECTA gene is responsible for the hearing loss in this Mongolian family
Reduced arsenic clearance and increased toxicity in aquaglyceroporin-9-null mice
Expressed in liver, aquaglyceroporin-9 (AQP9) is permeated by glycerol, arsenite, and other small, neutral solutes. To evaluate a possible protective role, AQP9-null mice were evaluated for in vivo arsenic toxicity. After injection with NaAsO(2), AQP9-null mice suffer reduced survival rates (LD(50), 12 mg/kg) compared with WT mice (LD(50), 15 mg/kg). The highest tissue level of arsenic is in heart, with AQP9-null mice accumulating 10-20 times more arsenic than WT mice. Within hours after NaAsO(2) injection, AQP9-null mice sustain profound bradycardia, despite normal serum electrolytes. Increased arsenic levels are also present in liver, lung, spleen, and testis of AQP9-null mice. Arsenic levels in the feces and urine of AQP9-null mice are only approximately 10% of the WT levels, and reduced clearance of multiple arsenic species by the AQP9-null mice suggests that AQP9 is involved in the export of multiple forms of arsenic. Immunohistochemical staining of liver sections revealed that AQP9 is most abundant in basolateral membrane of hepatocytes adjacent to the sinusoids. AQP9 is not detected in heart or kidney by PCR or immunohistochemistry. We propose that AQP9 provides a route for excretion of arsenic by the liver, thereby providing partial protection of the whole animal from arsenic toxicity
Two ultraviolet radiation datasets that cover China
Ultraviolet (UV) radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. One contains hourly observations of UV radiation measured at 40 Chinese Ecosystem Research Network stations from 2005 to 2015. CUV3 broadband radiometers were used to observe the UV radiation, with an accuracy of 5%, which meets the World Meteorology Organization's measurement standards. The extremum method was used to control the quality of the measured datasets. The other dataset contains daily cumulative UV radiation estimates that were calculated using an all-sky estimation model combined with a hybrid model. The reconstructed daily UV radiation data span from 1961 to 2014. The mean absolute bias error and root-mean-square error are smaller than 30% at most stations, and most of the mean bias error values are negative, which indicates underestimation of the UV radiation intensity. These datasets can improve our basic knowledge of the spatial and temporal variations in UV radiation. Additionally, these datasets can be used in studies of potential ozone formation and atmospheric oxidation, as well as simulations of ecological processes
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