Quantum Brain: A Recurrent Quantum Neural Network Model to Describe Eye Tracking of Moving Targets

A theoretical quantum brain model is proposed using a nonlinear Schroedinger wave equation. The model proposes that there exists a quantum process that mediates the collective response of a neural lattice (classical brain). The model is used to explain eye movements when tracking moving targets. Using a Recurrent Quantum Neural Network(RQNN) while simulating the quantum brain model, two very interesting phenomena are observed. First, as eye sensor data is processed in a classical brain, a wave packet is triggered in the quantum brain. This wave packet moves like a particle. Second, when the eye tracks a fixed target, this wave packet moves not in a continuous but rather in a discrete mode. This result reminds one of the saccadic movements of the eye consisting of 'jumps' and 'rests'. However, such a saccadic movement is intertwined with smooth pursuit movements when the eye has to track a dynamic trajectory. In a sense, this is the first theoretical model explaining the experimental observation reported concerning eye movements in a static scene situation. The resulting prediction is found to be very precise and efficient in comparison to classical objective modeling schemes such as the Kalman filter.Comment: 7 pages, 7 figures submitted to Physical Review Letter

Heat treatment enhances the plant phenolic (+)-catechin, a weak antimicrobial agent when combined with copper sulphate

The aim of the study was to compare the antimicrobial activities of freshly-made, heat-treated (HT), and 14 d stored (+)-Catechin solutions with (+)-catechin flavanol isomers in the presence of copper sulphate. (+)-Catechin activity was investigated when combined with different ratios of Cu(2+) ; 100°C heat treatment; autoclaving; and 14 d storage against Staphylococcus aureus. Cu(2+) -(+)-Catechin complexation, isomer structure-activity relationships, and H2 O2 generation were also investigated. Freshly-made, HT, and 14d stored flavanols showed no activity. Whilst combined Cu(2+) -autoclaved (+)-Catechin and -HT(+)-Catechin activities were similar, HT(+)-Catechin was more active than either freshly-made (+)-catechin (generating more H2 O2 ) or (-)-Epicatechin (though it generated less H2 O2 ) or 14d-(+)-Catechin (which had similar activity to Cu(2+) controls - though it generated more H2 O2 ). When combined with Cu(2+) , in terms of rates of activity, HT(+)-Catechin was lower than (-)-Epigallocatechin gallate and greater than freshly-made (+)-Catechin. Freshly-made and HT(+)-Catechin formed acidic complexes with Cu(2+) as indicated by pH and UV-vis measurements although pH changes did not account for antimicrobial activity. Freshly-made and HT(+)-Catechin both formed Cu(2+) complexes. The HT(+)-Catechin complex generated more H2 O2 which could explain its higher antimicrobial activity. This article is protected by copyright. All rights reserved

Quantum Mechanical Interaction-Free Measurements

A novel manifestation of nonlocality of quantum mechanics is presented. It is shown that it is possible to ascertain the existence of an object in a given region of space without interacting with it. The method might have practical applications for delicate quantum experiments.Comment: (revised file with no need for macro), 12, TAUP 1865-91

BACK TO THE SOURCE A combined trace elemental and multi-isotopic approach to provenance pre-colonial Caribbean jade artefacts: Implications for mobility and exchange networks

The determination of trace element (TE) abundances and multi-isotopic compositions (IC) of artefacts is a powerful tool that provides valuable information about their origin, manufacturing technology and authenticity. Such studies allow to conclude about the circulation of goods, past human interaction and ancient mobility networks. This dissertation aims to untangle the circulation of objects made of jade in the pre-colonial Caribbean through a multi-disciplinary approach employing development of a novel minimally-invasive sampling technique to generate geochemical and archaeological data sets and their interpretation with statistical modelling. To geochemically fingerprint objects stored in private and public institutions, very sensitive, ideally portable and non-invasive analytical techniques are demanded. Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) allows determination of major, minor and TE abundances in a quasi-non-destructive manner with limits of qualification/quantification (LOD and LOQ) in the lower ppb to sub-ppb range. Since LA-ICPMS is a laboratory-based bench set-up, it is neither accessible for cultural heritage objects which are immobile, nor to objects which exceed the dimensions of the closed ablation cell. To circumvent these limitations and to enable the analyses of isotope ratios, an analytical procedure involving an offline laser ablation sampling strategy was developed. This dissertation reports on the further optimization, validation and application of the 532 nm portable LA sampling technique with subsequent low-blank geochemical analyses. The method allows minimally-invasive in situ sampling of cultural heritage objects made of various materials, regardless of their mobility, geometry or size, leaving cone to cylinder shaped ablation pits with the diameter of hair, invisible to the naked eye, and hence maintaining the integrity of the archaeological/art object. Low-blank geochemical clean lab procedures, TE and strontium (Sr) and neodymium (Nd) analyses using quadrupole ICPMS and thermal ionisation mass spectrometry (TIMS) produced accurate, precise and reproducible data. The method was validated by taking ten ablations (25 to 40 µg) per sample of a USGS reference basalt glass and twenty ablations (50 to 80 µg) per sample of a natural jade slab. The outcome demonstrated that Sr and Nd isotope variability can be resolved in natural samples within the fourth decimal, which is sufficient to determine the provenance or authenticity. The laser system was applied to collect material from 88 pre-colonial jade artefacts unearthed from Early to Late Ceramic Age (400 BC to AD 1500) sites on Cuba (CU), the Dominican Republic (DR), St. John, St. Thomas, St. Croix, St. Vincent and Grenada. Samples ( 4000 km, connecting Caribbean islands with the Mesos- and South American mainland, including linchpin settlements with highly specialised workshops serving as important distribution centres, stimulated and boosted the exchange and mobility of goods, humans and ideas

Field Application of Spent Lime Water Treatment Residual for the Removal of Phosphorus and other Pollutants in Urban Stormwater Runoff

The threat of anthropogenic eutrophication and harmful algal blooms in lakes requires the development of innovative stormwater best management practices (BMPs) to reduce the external loading of phosphorus (P). This paper presents the findings of a 5-year study of a full-scale P removal structure constructed in Minnesota, USA with spent lime drinking water treatment residual (DWTR), a by-product of water softening at a local water treatment plant. Influent and effluent water samples were collected by auto-samplers during 43 storm events during the growing season. Samples were analyzed for P constituents, heavy metals, total suspended solids (TSS), and pH. Toxicity of the effluent was assessed using Ceriodaphnia dubia. Flow-weighted removal effectiveness was calculated for each storm event. Overall, the spent lime DWTR reduced total P loading by 70.9%, dissolved reactive P by 78.5%, dissolved P by 74.7%, and TSS by 58.5%. A significant reduction in heavy metals was also observed. Toxicity tests indicated the aquatic toxicity of the effluent treated with spent lime DWTR was not different from untreated stormwater. This study provided long-term real-world data that demonstrated that a full-scale P removal structure with spent lime DWTR significantly reduced P and other pollutants in stormwater discharging to an urban lake. Therefore, spent lime DWTR, which is currently treated as a waste product, is a promising filter material for stormwater treatment

A C-squared Polygonal Surface Patch

A polygonal patch is defined to fill an n-sided hole within a C2 parametric continuous rectangular patch complex

Seeing a c-theorem with holography

There is no known model in holography exhibiting a $c$-theorem where the central charges of the dual CFT are distinct. We examine a holographic model of RG flows in a framework where the bulk gravity theory contains higher curvature terms. The latter allows us to distinguish the flow of the central charges $a$ and $c$ in the dual field theories in four dimensions. One finds that the flow of $a$ is naturally monotonic but that of $c$ is not. Extending the analysis of holographic RG flows to higher dimensions, we are led to formulate a novel c-theorem in arbitrary dimensions for a universal coefficient appearing in the entanglement entropy of the fixed point CFT's.Comment: 5 pages, 1 figure, v2: minor change