Physical Resources for Quantum-enhanced Phase Estimation

We study the role of quantum entanglement (particle entanglement and mode entanglement) in optical phase estimation by employing the first and second quantization formalisms of quantum mechanics. The quantum Fisher information (QFI) is expressed as a function of the first and second order optical coherence functions. The resulting form of the QFI elucidates the deriving metrological resources for quantum phase estimation: field intensity and photon detection correlations. In addition, our analysis confirms that mode entanglement is not required for quantum-enhanced interferometry, whereas particle entanglement is a necessary requirement.Comment: 8 pages, 2 figures, 2 table

Antioksidacijski potencijal, maseni udjel i aktivnost antinutrijenata, sastav mineralnih tvari i FTIR spektri leguminoza fermentiranih s pomoću plijesni Rhizopus oligosporus

Research background. Legumes are superior sources of macro- and micronutrients which can be further enhanced by fermentation. This can assist in addressing the food security concerns. The present study aims to determine the effect of fermentation by Rhizopus oligosporus on nutritional and antinutritional composition of some commonly consumed legumes. Experimental approach. Chickpea (kabuli and desi), pigeon pea and soybean were fermented with Rhizopus oligosporus (at 34 °C for 52 h), dried at 45 °C for 16-18 h and milled. Antioxidant potential, phenolic composition, antinutrients, mineral composition and FTIR spectra of fermented and unfermented flour samples were evaluated. Results and conclusions. Fermentation significantly (p<0.05) enhanced the total phenolic and flavonoid contents, and antioxidant properties (radical scavenging activity, reducing power, ferric reducing antioxidant power and metal chelation) of kabuli and desi chickpeas, and soybean. Although fermented pigeon pea exhibited excellent antioxidant properties, the effect of fermentation on such properties was either minimal or insignificant. Additionally, quantification of specific phenolics using HPLC showed higher mass fractions of certain compounds such as chlorogenic, p-hydroxybenzoic, gallic and vanillic acids in fermented legumes. Mass fraction of phytic acid in all the fermented legumes was reduced (p<0.05), while trypsin inhibition increased (p<0.05). In kabuli and desi chickpeas, and pigeon pea, saponin mass fraction increased (p<0.05) while it decreased in soybean. Tannin mass fraction increased (p<0.05) in desi chickpea, pigeon pea and soybean and decreased (p<0.05) in kabuli chickpea. Furthermore, fermentation enhanced the content and estimated bioavailability of minerals. FTIR spectrum of fermented and unfermented legumes showed the presence of several functional groups and modifications in the molecular structure after fermentation. Novelty and scientific contribution. To our knowledge, this is the first study where legume (kabuli and desi chickpeas, pigeon pea and soybean) fermentation by Rhizopus oligosporus has been assessed for nutritional and antinutritional profile and FTIR spectra. We concluded that the treatment resulted in an optimal balance of nutrients and antinutrients. The process proved to be a potential tool for tackling the concerns of nutritional security, and thus can be proposed for the development of novel legume-based functional foods.Pozadina istraživanja. Leguminoze su vrlo bogat izvor makro- i mikronutrijenata, čiji se potencijal može povećati fermentacijom, a time i riješiti problem sigurne primjene tih namirnica. Svrha je ovoga rada bila utvrditi učinak fermentacije s pomoću plijesni Rhizopus oligosporus na nutritivni i antinutritivni sastav najčešće korištenih leguminoza. Eksperimentalni pristup. Slanutak (sorte kabuli i desi), golublji grašak i soja fermentirani su s pomoću plijesni Rhizopus oligosporus (pri 34 °C tijekom 52 h), sušeni na 45 °C tijekom 16-18 h te samljeveni. Zatim su ispitani antioksidacijski potencijal, fenolni sastav, maseni udjel i aktivnost antinutrijenata, sastav mineralnih tvari i FTIR spektri fermentiranih i nefermeniranih uzoraka brašna. Rezultati i zaključci. Fermentacijom su se bitno (p<0,05) povećali udjeli ukupnih fenola i flavonoida, te poboljšala antioksidacijska svojstva (sposobnost uklanjanja slobodnih radikala, redukcijska snaga, antioksidacijska snaga i svojstvo keliranja metala) obiju sorti slanutka i soje. Iako je fermentirani golublji grašak imao odlična antioksidacijska svojstva, učinak fermentacije na ta svojstva bio je minimalan ili neznatan. Osim toga, metodom HPLC određeni su maseni udjeli specifičnih fenola u fermentiranim leguminozama, od kojih su najzastupljeniji bili spojevi poput klorogenske, p-hidroksibenzojeve, galne i vanilinske kiseline. Fermentacijom se smanjio (p<0,05) maseni udjel fitinske kiseline u svim leguminozama, dok se aktivnost inhibitora tripsina povećala (p<0,05). U obje sorte slanutka i u golubljem grašku maseni se udjel saponina povećao (p<0,05), dok se u soji smanjio. Maseni se udjel tanina povećao (p<0,05) u sorti slanutka desi, golubljem grašku i soji, a smanjio (p<0,05) u sorti slanutka kabuli. Nadalje, fermentacija je povećala udjel i procijenjenu biodostupnost mineralnih tvari. FTIR spektri fermentiranih i nefermentiranih leguminoza potvrdili su prisutnost nekoliko funkcionalnih skupina i promjenu strukture molekula nakon fermentacije. Novina i znanstveni doprinos. Prema našim spoznajama, ovo je prvo istraživanje u kojem su ispitani nutritivni i antinutritivni profil te FTIR spektri leguminoza (slanutak sorata kabuli i desi, golublji grašak i soja) fermentiranih s pomoću plijesni Rhizopus oli¬gosporus. Zaključeno je da je fermentacijom postignut balans između nutrijenata i antinutrijenata. Dokazano je da se ovaj postupak može primijeniti kao sredstvo rješavanja problema sigurnosti hrane, te predložiti za razvoj nove funkcionalne hrane na osnovi leguminoza

BORA ON THE NORTHERN ADRIATIC, 12-18 APRIL 1982

Analysis is presented of a bora case on 12-18 April 1982, characterized by the longest bora duration in Senj (138 hours) during the ALPEX-SOP. The bora was observed only on the northern Adriatic. The vertical wind and stability profiles indicate that the part of the upstream inversion layer decoupled and descended toward the sea which is confirmed in the aircraft data analysis (Smith, 1987). The application of the generalized hydraulic theory on the continuously stratified atmosphere showed that the theory can successfully explain the bora phenomenon in the postfrontal bora situation

Quantum-enhanced Phase Estimation in Optical Interferometry

Quantum-enhanced interferometers utilize non-classical states of light in order to surpass the limitations imposed by classical physics on phase measurement sensitivity and resolution. We review key scientific developments in this growing field of research and derive fundamental metrology concepts, namely the Cram\'{e}r-Rao bound and the Fisher information, which are used to analyze the metrological performance of quantum states of light. We propose a supersensitive quantum interferometry protocol that can be amplified to the macroscopic realm (i.e. the mean number of photons of the probe state can reach approximately 100,000 photons) using contemporary techniques of spontaneous parametric down conversion. The parity measurement on the output field asymptotically saturates the quantum Cram\'{e}r-Rao bound, which scales like the Heisenberg limit. We uncover the role of photon statistics on phase sensitivity and rule out the necessity of mode entanglement for quantum-enhanced interferometry. Based on these insights we outline a practical metrology technique (independent of mode entanglement) that measures a phase delay of a single-mode anti-squeezing operation. This scheme can also be scaled macroscopically using contemporary techniques and is shown to significantly surpass the shot-noise limit (SNL) in the presence of realistic losses. Finally, the physical resources that enable quantum-enhanced interferometry is studied by analyzing the quantum Fisher information (QFI) using the first quantization and the second quantization formalisms of quantum mechanics. It is shown that increasing the intra-mode correlations of an interferometer (as quantified by the second order Glauber coherence function) can be conducive to attaining a quantum advantage in phase estimation; whereas, introducing mode entanglement can reduce phase sensitivity. Using the first quantization description, we derive a formula for the QFI that shows explicitly how the Heisenberg scaling term depends on particle entanglement.Ph.D

Quantum correlations in optical metrology: Heisenberg-limited phase estimation without mode entanglement

The quantum fisher information and quantum correlation parameters are employed to study the application of non-classical light to the problem of parameter estimation. It is shown that the optimal measurement sensitivity of a quantum state is determined by its inter-mode correlations (which depends of path-entanglement) and intra-mode correlations (which depends of the photon statistics). In light of these results, we consider the performance of quantum-enhanced optical interferometers. Furthermore, we propose a Heisenberg-limited metrology protocol involving standard elements from passive and active linear optics, for which the quantum Cram\'{e}r-Rao bound is saturated with an intensity measurement. Interestingly, the quantum advantage for this scheme is derived solely from the non-classical photon statistics of the probe state and does not depend of entanglement. We study the performance of this scheme in the presence of realistic losses and consequently predict a substantial enhancement over the shot-noise limit with current technological capabilities.Comment: 8 pages, 3 figures, 1 tabl

Investigations to underpin the development of bacteriophages as therapeutic agents to target pseudomonas aeruginosa infections in patients with cystic fibrosis

Pseudomonas aeruginosa is very adept at evolving antimicrobial resistance, which severely reduces the effectiveness of antibiotic treatments available. This contributes to it being the primary cause of morbidity and mortality associated with cystic fibrosis (CF). A new strategy is needed to target P. aeruginosa, a promising approach is bacteriophage (phage) therapy. The aim of this study was to look at developing a phage based therapeutic for airway associated P. aeruginosa infections. This included isolation and characterisation of suitable phages, in vitro and ex vivo testing against clinical P. aeruginosa strains, delivery methods, purification and resistance detection. Seven phages were isolated from commercial and environmental sources. Some of these had suitable host ranges against clinical strains, and were capable of biofilm prevention and degradation. Although these phages were effective in vitro, their efficiency was increased when combined with each other, or the antibiotic tobramycin. Although resistance was observed in these experimental systems, the use of multiple phages reduced resistance development, and resistant strains displayed both a reduction in virulence and an increase in sensitivity to CF antibiotics. Testing with three nebulisers demonstrated these phages could successfully be aerosolised to produce sizes where they would be expected to reach to the lower airways. When aerosolised on to an ex vivo healthy and CF ciliated cell line model, the phages were also able to prevent the establishment of an infection. The purity of the phages was an issue in cell models due to endotoxin contamination; however, various purification methods were developed and tested, with anion-exchange chromatography lowering the levels by three logs, just above the British legal limits. The results from this study demonstrate the potential of a phage based prophylactic against respiratory P. aeruginosa infections. With additional properties that could widen their use against nosocomial infections

Quantum correlations in optical metrology: Heisenberg-limited phase estimation without mode entanglement

The quantum fisher information and quantum correlation parameters are employed to study the application of non-classical light to the problem of parameter estimation. It is shown that the optimal measurement sensitivity of a quantum state is determined by its inter-mode correlations (which depends of path-entanglement) and intra-mode correlations (which depends of the photon statistics). In light of these results, we consider the performance of quantum-enhanced optical interferometers. Furthermore, we propose a Heisenberg-limited metrology protocol involving standard elements from passive and active linear optics, for which the quantum Cram\'{e}r-Rao bound is saturated with an intensity measurement. Interestingly, the quantum advantage for this scheme is derived solely from the non-classical photon statistics of the probe state and does not depend of entanglement. We study the performance of this scheme in the presence of realistic losses and consequently predict a substantial enhancement over the shot-noise limit with current technological capabilities.Comment: 8 pages, 3 figures, 1 tabl