Automated Sleep Apnea Quantification Based on Respiratory Movement

Obstructive sleep apnea (OSA) is a prevalent and treatable disorder of neurological and medical importance that is traditionally diagnosed through multi-channel laboratory polysomnography(PSG). However, OSA testing is increasingly performed with portable home devices using limited physiological channels. We tested the hypothesis that single channel respiratory effort alone could support automated quantification of apnea and hypopnea events. We developed a respiratory event detection algorithm applied to thoracic strain-belt data from patients with variable degrees of sleep apnea. We optimized parameters on a training set (n=57) and then tested performance on a validation set (n=59). The optimized algorithm correlated significantly with manual scoring in the validation set (R2 = 0.73 for training set, R2 = 0.55 for validation set; p0.92 and >0.85 using apnea-hypopnea index cutoff values of 5 and 15, respectively. Our findings demonstrate that manually scored AHI values can be approximated from thoracic movements alone. This finding has potential applications for automating laboratory PSG analysis as well as improving the performance of limited channel home monitors

Positivity of energy for asymptotically locally AdS spacetimes

We derive necessary conditions for the spinorial Witten-Nester energy to be well-defined for asymptotically locally AdS spacetimes. We find that the conformal boundary should admit a spinor satisfying certain differential conditions and in odd dimensions the boundary metric should be conformally Einstein. We show that these conditions are satisfied by asymptotically AdS spacetimes. The gravitational energy (obtained using the holographic stress energy tensor) and the spinorial energy are equal in even dimensions and differ by a bounded quantity related to the conformal anomaly in odd dimensions.Comment: 36 pages, 1 figure; minor corrections, JHEP versio

Topologically Massive Gravity and the AdS/CFT Correspondence

We set up the AdS/CFT correspondence for topologically massive gravity (TMG) in three dimensions. The first step in this procedure is to determine the appropriate fall off conditions at infinity. These cannot be fixed a priori as they depend on the bulk theory under consideration and are derived by solving asymptotically the non-linear field equations. We discuss in detail the asymptotic structure of the field equations for TMG, showing that it contains leading and subleading logarithms, determine the map between bulk fields and CFT operators, obtain the appropriate counterterms needed for holographic renormalization and compute holographically one- and two-point functions at and away from the 'chiral point' (mu = 1). The 2-point functions at the chiral point are those of a logarithmic CFT (LCFT) with c_L = 0, c_R = 3l/G_N and b = -3l/G_N, where b is a parameter characterizing different c = 0 LCFTs. The bulk correlators away from the chiral point (mu \neq 1) smoothly limit to the LCFT ones as mu \to 1. Away from the chiral point, the CFT contains a state of negative norm and the expectation value of the energy momentum tensor in that state is also negative, reflecting a corresponding bulk instability due to negative energy modes.Comment: 54 pages, v2: added comments and reference

Optical proxies for terrestrial dissolved organic matter in estuaries and coastal waters

Dissolved organic matter (DOM) absorbance and fluorescence were used as optical proxies to track terrestrial DOM fluxes through estuaries and coastal waters by comparing models developed for several coastal ecosystems. Key to using these optical properties is validating and calibrating them with chemical measurements, such as lignin-derived phenols-a proxy to quantify terrestrial DOM. Utilizing parallel factor analysis (PARAFAC), and comparing models statistically using the OpenFluor database (http://www.openfluor.org) we have found common, ubiquitous fluorescing components which correlate most strongly with lignin phenol concentrations in several estuarine and coastal environments. Optical proxies for lignin were computed for the following regions: Mackenzie River Estuary, Atchafalaya River Estuary (ARE), Charleston Harbor, Chesapeake Bay, and Neuse River Estuary (NRE) (all in North America). The slope of linear regression models relating CDOM absorption at 350 nm (a350) to DOC and to lignin, varied 5-10-fold among systems. Where seasonal observations were available from a region, there were distinct seasonal differences in equation parameters for these optical proxies. The variability appeared to be due primarily to river flow into these estuaries and secondarily to biogeochemical cycling of DOM within them. Despite the variability, overall models using single linear regression were developed that related dissolved organic carbon (DOC) concentration to CDOM (DOC = 40 ± 2 × a350 + 138 ± 16; R2 = 0.77; N = 130) and lignin (Σ8) to CDOM (Σ8 = 2.03 ± 0.07 × a350 - 0.47 ± 0.59; R2 = 0.87; N = 130). This wide variability suggested that local or regional optical models should be developed for predicting terrestrial DOM flux into coastal oceans and taken into account when upscaling to remote sensing observations and calibrations

Identification of a 2-propanol analogue modulating the non-enzymatic function of indoleamine 2,3-dioxygenase 1

Abstract Indoleamine 2,3 dioxygenase 1 (IDO1) is a metabolic enzyme that catalyzes the conversion of the essential amino acid tryptophan (Trp) into a series of immunoactive catabolites, collectively known as kynurenines. Through the depletion of Trp and the generation of kynurenines, IDO1 represents a key regulator of the immune responses involved in physiologic homeostasis as well as in neoplastic and autoimmune pathologies. The IDO1 enzyme has been described as an important immune checkpoint to be targeted by catalytic inhibitors in the treatment of cancer. In contrast, a defective expression/activity of the enzyme has been demonstrated in autoimmune diseases. Beside its catalytic activity, the IDO1 protein is endowed with an additional function associated with the presence of two immunoreceptor tyrosine-based inhibitory motifs (ITIMs), which, once phosphorylated, bind SHP phosphatases and mediate a long-term immunoregulatory activity of IDO1. Herein, we report the screening of a focused library of molecules bearing a propanol core by a protocol combining microscale thermophoresis (MST) analysis and a cellular assay. As a result, the combined screening identified a 2-propanolol analogue, VIS351, as the first potent activator of the ITIM-mediated function of the IDO1 enzyme. VIS351 displayed a good dissociation constant (Kd = 1.90 μM) for IDO1 and a moderate cellular inhibitor activity (IC50 = 11.463 μM), although it did not show any catalytic inhibition of the recombinant IDO1 enzyme. Because we previously demonstrated that the enzymatic and non-enzymatic (i.e., ITIM-mediated) functions of IDO1 reside in different conformations of the protein, we hypothesized that in the cellular system VIS351 may shift the dynamic conformational balance towards the ITIM-favoring folding of IDO1, resulting in the activation of the signaling rather than catalytic activity of IDO1. We demonstrated that VIS351 activated the ITIM-mediated signaling of IDO1 also in mouse plasmacytoid dendritic cells, conferring those cells an immunosuppressive phenotype detectable in vivo. Thus the manuscript describes for the first time a small molecule as a positive modulator of IDO1 signaling function, paving the basis for an innovative approach to develop first-in-class drugs acting on the IDO1 target

Holographic Description of Gravitational Anomalies

The holographic duality can be extended to include quantum theories with broken coordinate invariance leading to the appearance of the gravitational anomalies. On the gravity side one adds the gravitational Chern-Simons term to the bulk action which gauge invariance is only up to the boundary terms. We analyze in detail how the gravitational anomalies originate from the modified Einstein equations in the bulk. As a side observation we find that the gravitational Chern-Simons functional has interesting conformal properties. It is invariant under conformal transformations. Moreover, its metric variation produces conformal tensor which is a generalization of the Cotton tensor to dimension $d+1=4k-1, k\in Z$. We calculate the modification of the holographic stress-energy tensor that is due to the Chern-Simons term and use the bulk Einstein equations to find its divergence and thus reproduce the gravitational anomaly. Explicit calculation of the anomaly is carried out in dimensions $d=2$ and $d=6$. The result of the holographic calculation is compared with that of the descent method and agreement is found. The gravitational Chern-Simons term originates by Kaluza-Klein mechanism from a one-loop modification of M-theory action. This modification is discussed in the context of the gravitational anomaly in six-dimensional $(2,0)$ theory. The agreement with earlier conjectured anomaly is found.Comment: 24 pages, Latex; presentation re-structured, new references adde

Non-Extremal D-instantons and the AdS/CFT Correspondence

We investigate non-extremal D-instantons in an asymptotically $AdS_5 \times S^5$ background and the role they play in the $AdS_5 / CFT_4$ correspondence. We find that the holographic dual operators of non-extremal D-instanton configurations do not correspond to self-dual Yang-Mills instantons, and we compute explicitly the deviation from self-duality. Furthermore, a class of non-extremal D-instantons yield Euclidean axionic wormhole solutions with two asymptotic boundaries. After Wick rotating, this provides a playground for investigating holography in the presence of cosmological singularities in a closed universe.Comment: 30 pages, 3 figure

Adding flavor to AdS/CFT

Coupling fundamental quarks to QCD in the dual string representation corresponds to adding the open string sector. Flavors therefore should be represented by space-time filling D-branes in the dual 5d closed string background. This requires several interesting properties of D-branes in AdS. D-branes have to be able to end in thin air in order to account for massive quarks, which only live in the UV region. They must come in distinct sets, representing the chiral global symmetry, with a bifundamental field playing the role of the chiral condensate. We show that these expectations are born out in several supersymmetric examples. To analyze most of these properties it is not necessary to go beyond the probe limit in which one neglects the backreaction of the flavor D-branes.Comment: 14 pages, LaTeX; references adde

RAW MILK AT VENDING MACHINES: EVALUATION OF E. SAKAZAKII, COXIELLA BURNETII AND M. PARATUBERCULOSIS IN PIEDMONT EXPERIENCE

Italian consumers changed their food habits in the last period; the increase of raw milk consuming is also related to the high number of self service vending machines that have been authorized, particularly in Northern Italy. According to national rules on raw milk hygienic conditions, the most important bacteria are checked by Veterinary Services; the aim of this study was to investigate some emerging or re-emerging hazards in raw milk at vending machines. For this reason 100 raw milk samples were collected and analyzed in order to detect E. sakazakii, Coxiella burnetii and M. avium subsp paratuberculosis. One milk sample resulted to be positive with PCR method for E. sakazakii (no cultural confirmation was possible); 49% of samples resulted posivite for the presence of Coxiella burnetii specific DNA, and 5% of milk samples came out positive to the presence of M. paratuberuclosis antibodies with ELISA methods

A renormalisable non-anticommutative SU(N)xU(1) gauge theory in components

We discuss the non-anticommutative (N=1/2) supersymmetric SU(N)\otimes U(1) gauge theory including a superpotential. We show how recent proposals for obtaining a renormalisable version of the theory may be implemented in the component formalism at the one-loop level.Comment: 25pp, 14 figures, LaTeX; minor typo fixed, reference added, notation clarifie