Einstein-Podolsky-Rosen Paradox with Position-Momentum Entangled Macroscopic Twin Beams

Spatial entanglement is at the heart of quantum enhanced imaging applications and high-dimensional quantum information protocols. In particular, for imaging and sensing applications, quantum states with a macroscopic number of photons are needed to provide a real advantage over the classical state-of-the-art. We demonstrate the Einstein-Podolsky-Rosen (EPR) paradox in its original position and momentum form with bright twin beams of light by showing the presence of EPR spatial (position-momentum) entanglement. An electron-multiplying charge-coupled-device camera is used to record images of the bright twin beams in the near and far field regimes to achieve an apparent violation of the uncertainty principle by more than an order of magnitude. We further show that the presence of quantum correlations in the spatial and temporal degrees of freedom leads to spatial squeezing between the spatial fluctuations of the bright twin beams in both the near and far fields. This provides another verification of the spatial entanglement and points to the presence of hyperentanglement in the bright twin beams.Comment: 5 pages, 3 Figures. Includes Supplemental Materia

Information encoding in the spatial correlations of entangled twin beams

The ability to use the temporal and spatial degrees of freedom of quantum states of light to encode and transmit information is crucial for the implementation of a robust and efficient quantum network. In particular, the large dimensionality of the spatial degree of freedom promises to provide significant enhancements; however, such promise has largely been unfulfilled as the necessary level of control over the spatial degree of freedom to encode information remains elusive. Here, we show that information can be encoded in the distribution of the spatial correlations of highly multi-spatial mode entangled bright twin beams. We take advantage of the dependence of the spatial correlations on the angular spectrum of the pump required for four-wave mixing, as dictated by phase matching. The encoded information can be extracted by mapping the momenta distribution of the twin beams to a position distribution in the far field and measuring the spatial cross-correlation of images acquired with a high quantum efficiency electron multiplying charge coupled device. We further show that the encoded information cannot be accessed through individual beam measurements and that the temporal quantum correlations are not modified. We anticipate that the ability to engineer the distribution of the spatial correlations will serve as a novel degree of freedom to encode information and hence provide a pathway for high capacity quantum information channels and networks. In addition, a high degree of control over the spatial properties of quantum states of light will enable real-world quantum-enhanced spatially resolved sensing and imaging applications

Study of polyembryony and development of molecular markers for identification of zygotic and nucellar seedlings in Khasi mandarin (Citrus reticulata Blanco)

The objective of this work was to evaluate the occurrence of polyembryonic seedlings and other morphological parameters in Khasi mandarin during three harvest years and to identify zygotic (sexual) seedlings from nucellar (asexual) ones grown under in-vitro conditions using molecular markers. Embryos from 27 polyembryonic and 7 monoembryonic seeds of Khasi mandarin were grown in-vitro. DNA from seedlings and mother parent was analyzed using 16 ISSR and 5 RAPD primers, of which 4 ISSR and a set of 3 RAPD primers were effective to identify zygotic or nucellar origin of the seedlings. In-vitro culture enables maximum embryos of each seed to grow, favouring the origin of seedlings to be identified as zygotic. Among 69 tested individuals, 37 zygotic and 32 nucellar seedlings were recognized. In polyembryonic and monoembryonic seeds, 59.6% and 42.8% of the seedlings, respectively, have the sexual origin. Morphological characteristics of seeds and the seedlings generated varied significantly and were not correlated with polyembryony except for the clutch size and the number of branches. Polyembryonic seeds in the cultivar are high, ranging from 50.0%, 55.5% to 83.3% over three harvest years with more clutch size and the possibility of obtaining zygotic plants from them is high. In polyembryonic seeds not all zygotic seedlings were produced by small embryos located at the micropyle. Identification of zygotic seedlings by ISSR and RAPD markers in Khasi mandarin cultivar is efficient and reliable at an early developmental stage

Encapsulated somatic embryos of grape (Vitis vinifera L.): An efficient way for storage and propagation of pathogen-free plant material

Cotyledonary-stage somatic embryos (5-7 mm in length) originating from leaf explants of grape (Vitis vinifera L.) cv. Pusa seedless were encapsulated individually in 2 % alginate gel. The encapsulated somatic embryos (ESEs) germinated successfully on 0.7 % agar medium containing B5 macrosalts (half strength), MURASHIGE and SKOOG microsalts (full strength), 3 % sucrose and 2.9 μM gibberellic acid. The percentage of germination of ESEs was higher than that of nonencapsulated somatic embryos (NSEs) of the same size on the same medium. The percent germination of ESEs increased (69.2 ±2.8) on medium supplemented with quarter strength B5 macrosalts. Of the germinating ESEs, 36 % developed into plantlets. Abscisic acid at 0.004 and 0.02 μM had no significant influence on the frequency of germination and plantlet development, however resulted in a 4-week delay in germination. Transferring the embryos onto the full-strength B5 medium containing sucrose and ABA (0.04 μM) for 4-6 weeks prior to encapsulation resulted in extended storage of up to 90 d without loss of the germination potential and the capacity to regenerate into plantlets. Normally developed plantlets regenerated from ESEs were successfully adapted to soil.

Drosophila Sirt2/mammalian SIRT3 deacetylates ATP synthase beta and regulates complex V activity

Adenosine triphosphate (ATP) synthase beta, the catalytic subunit of mitochondrial complex V, synthesizes ATP. We show that ATP synthase beta is deacetylated by a human nicotinamide adenine dinucleotide (NAD(+))-dependent protein deacetylase, sirtuin 3, and its Drosophila melanogaster homologue, dSirt2. dsirt2 mutant flies displayed increased acetylation of specific Lys residues in ATP synthase beta and decreased complex V activity. Overexpression of dSirt2 increased complex V activity. Substitution of Lys 259 and Lys 480 with Arg in human ATP synthase beta, mimicking deacetylation, increased complex V activity, whereas substitution with Gln, mimicking acetylation, decreased activity. Mass spectrometry and proteomic experiments from wild-type and dsirt2 mitochondria identified the Drosophila mitochondrial acetylome and revealed dSirt2 as an important regulator of mitochondrial energy metabolism. Additionally, we unravel a ceramide-NAD(+)-sirtuin axis wherein increased ceramide, a sphingolipid known to induce stress responses, resulted in depletion of NAD(+) and consequent decrease in sirtuin activity. These results provide insight into sirtuin-mediated regulation of complex V and reveal a novel link between ceramide and Drosophila acetylome

Survival response to increased ceramide involves metabolic adaptation through novel regulators of glycolysis and lipolysis

The sphingolipid ceramide elicits several stress responses, however, organisms survive despite increased ceramide but how they do so is poorly understood. We demonstrate here that the AKT/FOXO pathway regulates survival in increased ceramide environment by metabolic adaptation involving changes in glycolysis and lipolysis through novel downstream targets. We show that ceramide kinase mutants accumulate ceramide and this leads to reduction in energy levels due to compromised oxidative phosphorylation. Mutants show increased activation of Akt and a consequent decrease in FOXO levels. These changes lead to enhanced glycolysis by upregulating the activity of phosphoglyceromutase, enolase, pyruvate kinase, and lactate dehydrogenase to provide energy. A second major consequence of AKT/FOXO reprogramming in the mutants is the increased mobilization of lipid from the gut through novel lipase targets, CG8093 and CG6277 for energy contribution. Ubiquitous reduction of these targets by knockdown experiments results in semi or total lethality of the mutants, demonstrating the importance of activating them. The efficiency of these adaptive mechanisms decreases with age and leads to reduction in adult life span of the mutants. In particular, mutants develop cardiac dysfunction with age, likely reflecting the high energy requirement of a well-functioning heart. The lipases also regulate physiological triacylglycerol homeostasis and are important for energy metabolism since midgut specific reduction of them in wild type flies results in increased sensitivity to starvation and accumulation of triglycerides leading to cardiac defects. The central findings of increased AKT activation, decreased FOXO level and activation of phosphoglyceromutase and pyruvate kinase are also observed in mice heterozygous for ceramide transfer protein suggesting a conserved role of this pathway in mammals. These data reveal novel glycolytic and non-autonomous lipolytic pathways in response to increased ceramide for sustenance of high energy demanding organ functions like the heart

Particle suspension reactors and materials for solar-driven water splitting

Reactors based on particle suspensions for the capture, conversion, storage, and use of solar energy as H_2 are projected to be cost-competitive with fossil fuels. In light of this, this review paper summarizes state-of-the-art particle light absorbers and cocatalysts as suspensions (photocatalysts) that demonstrate visible-light-driven water splitting on the laboratory scale. Also presented are reactor descriptions, theoretical considerations particular to particle suspension reactors, and efficiency and performance characterization metrics. Opportunities for targeted research, analysis, and development of reactor designs are highlighted