Heart Rate Extraction from Novel Neck Photoplethysmography Signals.

This paper demonstrates for the first time how heart rate (HR) can be extracted from novel neck photoplethysmography (PPG). A novel algorithm is presented, which when tested in neck PPG signals recorded from 9 subjects at different respiratory rates, obtained good precision with respect to gold standard ECG signals. Mean absolute error (MAE), standard deviation error (SDAE) and root-mean-square error (RMSE) resulted in 1.22, 1.54 and 1.98 beats per minute (BPM), respectively. HRneck estimation showed strong correlation (R=0.94) with reference HRECG. Good agreement between both techniques was also demonstrated by Bland-Altman analysis. The bias between mean HR paired differences was -0.16 BPM and 95% limits of agreement (LoA) were (-4.7, 4.4). Comparatively, for widely used finger PPG, errors were slightly smaller (MAE=0.38 BPM, SDAE=0.48 BPM, RMSE=0.62BPM) and the correlation with reference ECG was also very close to 1 (R=0.99). Bias of -0.04 BPM and 95% LoA (-1.5, 1.4), also showed high degree of agreement. However, these findings show the potential the neck could have as an alternative body location for wearable monitors, aiming to reduce the number of sensing sites whilst still providing access to a wide variety of physiological parameters

Pollution and the State: The Role of the Structure of Government

Government spending has significant environmental implications. This paper analyzes the effect of the allocation of government spending between public goods broadly defined and private goods or non-social subsidies on air and water pollution. The theoretical model predicts that a reallocation of expenditures from private subsidies to public goods improves environmental quality by reducing production pollution. We estimate an empirical model that shows that such a reallocation causes a significant reduction in air pollutants namely sulfur dioxide and lead and an improvement in water quality measures including dissolved oxygen and biological oxygen demand.

Surface wind convergence as a short-term predictor of cloud-to-ground lightning at Kennedy Space Center: A four-year summary and evaluation

Since 1986, USAF forecasters at NASA-Kennedy have had available a surface wind convergence technique for use during periods of convective development. In Florida during the summer, most of the thunderstorm development is forced by boundary layer processes. The basic premise is that the life cycle of convection is reflected in the surface wind field beneath these storms. Therefore the monitoring of the local surface divergence and/or convergence fields can be used to determine timing, location, longevity, and the lightning hazards which accompany these thunderstorms. This study evaluates four years of monitoring thunderstorm development using surface wind convergence, particularly the average over the area. Cloud-to-ground (CG) lightning is related in time and space with surface convergence for 346 days during the summers of 1987 through 1990 over the expanded wind network at KSC. The relationships are subdivided according to low level wind flow and midlevel moisture patterns. Results show a one in three chance of CG lightning when a convergence event is identified. However, when there is no convergence, the chance of CG lightning is negligible

Coulomb correlations of a few body system of spatially separated charges

A Hartree-Fock and Hartree-Fock-Bogoliubov study of a few body system of spatially separated charge carriers was carried out. Using these variational states, we compute an approximation to the correlation energy of a finite system of electron-hole pairs. This energy is shown as a function of the Coulomb coupling and the interplane distance. We discuss how the correlation energy can be used to theoretically determine the formation of indirect excitons in semiconductors which is relevant for collective phenomena such as Bose-Einstein condensation (BEC).Comment: Conference EDISON16 (2009), 4 page

Phenomenology Tools on Cloud Infrastructures using OpenStack

We present a new environment for computations in particle physics phenomenology employing recent developments in cloud computing. On this environment users can create and manage "virtual" machines on which the phenomenology codes/tools can be deployed easily in an automated way. We analyze the performance of this environment based on "virtual" machines versus the utilization of "real" physical hardware. In this way we provide a qualitative result for the influence of the host operating system on the performance of a representative set of applications for phenomenology calculations.Comment: 25 pages, 12 figures; information on memory usage included, as well as minor modifications. Version to appear in EPJ

Making Ends Meet: String Unification and Low-Energy Data

A long-standing problem in string phenomenology has been the fact that the string unification scale disagrees with the GUT scale obtained by extrapolating low-energy data within the framework of the minimal supersymmetric standard model (MSSM). In this paper we examine several effects that may modify the minimal string predictions and thereby bring string-scale unification into agreement with low-energy data. These include heavy string threshold corrections, non-standard hypercharge normalizations, light SUSY thresholds, intermediate gauge structure, and thresholds arising from extra matter beyond the MSSM. We explicitly evaluate these contributions within a variety of realistic free-fermionic string models, including the flipped SU(5), SO(6) x SO(4), and various SU(3) x SU(2) x U(1) models, and find that most of these sources do not substantially alter the minimal string predictions. Indeed, we find that the only way to reconcile string unification with low-energy data is through certain types of extra matter. Remarkably, however, many of the realistic string models contain precisely this required matter in their low-energy spectra.Comment: 10 pages, standard LaTeX, 1 figure (Encapsulated PostScript), version published in Phys. Rev. Lett. 75 (1995) 264

Extracting the jugular venous pulse from anterior neck contact photoplethysmography

The jugular venous pulse (JVP) is the reference physiological signal used to detect right atrial and central venous pressure (CVP) abnormalities in cardio-vascular diseases (CVDs) diagnosis. Invasive central venous line catheterization has always been the gold standard method to extract it reliably. However, due to all the risks it entails, novel non-invasive approaches, exploiting distance cameras and lasers, have recently arisen to measure the JVP at the external and internal jugular veins. These remote options however, constraint patients to very specific body positions in front of the imaging system, making it inadequate for long term monitoring. In this study, we demonstrate, for the first time, that reflectance photoplethysmography (PPG) can be an alternative for extracting the JVP from the anterior jugular veins, in a contact manner. Neck JVP-PPG signals were recorded from 20 healthy participants, together with reference ECG and arterial finger PPG signals for validation. B-mode ultrasound imaging of the internal jugular vein also proved the validity of the proposed method. The results show that is possible to identify the characteristic a, c, v pressure waves in the novel signals, and confirm their cardiac-cycle timings in consistency with established cardiac physiology. Wavelet coherence values (close to 1 and phase shifts of ±180°) corroborated that neck contact JVP-PPG pulses were negatively correlated with arterial finger PPG. Average JVP waveforms for each subject showed typical JVP pulses contours except for the singularity of an unknown "u" wave occurring after the c wave, in half of the cohort. This work is of great significance for the future of CVDs diagnosis, as it has the potential to reduce the risks associated with conventional catheterization and enable continuous non-invasive point-of-care monitoring of CVP, without restricting patients to limited postures

Gene deficiency in activating Fcγ receptors influences the macrophage phenotypic balance and reduces atherosclerosis in mice

Immunity contributes to arterial inflammation during atherosclerosis. Oxidized low-density lipoproteins induce an autoimmune response characterized by specific antibodies and immune complexes in atherosclerotic patients. We hypothesize that specific Fcγ receptors for IgG constant region participate in atherogenesis by regulating the inflammatory state of lesional macrophages. In vivo we examined the role of activating Fcγ receptors in atherosclerosis progression using bone marrow transplantation from mice deficient in γ-chain (the common signaling subunit of activating Fcγ receptors) to hyperlipidemic mice. Hematopoietic deficiency of Fcγ receptors significantly reduced atherosclerotic lesion size, which was associated with decreased number of macrophages and T lymphocytes, and increased T regulatory cell function. Lesions of Fcγ receptor deficient mice exhibited increased plaque stability, as evidenced by higher collagen and smooth muscle cell content and decreased apoptosis. These effects were independent of changes in serum lipids and antibody response to oxidized low-density lipoproteins. Activating Fcγ receptor deficiency reduced pro-inflammatory gene expression, nuclear factor-κB activity, and M1 macrophages at the lesion site, while increasing anti-inflammatory genes and M2 macrophages. The decreased inflammation in the lesions was mirrored by a reduced number of classical inflammatory monocytes in blood. In vitro, lack of activating Fcγ receptors attenuated foam cell formation, oxidative stress and pro-inflammatory gene expression, and increased M2-associated genes in murine macrophages. Our study demonstrates that activating Fcγ receptors influence the macrophage phenotypic balance in the artery wall of atherosclerotic mice and suggests that modulation of Fcγ receptor-mediated inflammatory responses could effectively suppress atherosclerosis

A Layman's guide to SUSY GUTs

The determination of the most straightforward evidence for the existence of the Superworld requires a guide for non-experts (especially experimental physicists) for them to make their own judgement on the value of such predictions. For this purpose we review the most basic results of Super-Grand unification in a simple and clear way. We focus the attention on two specific models and their predictions. These two models represent an example of a direct comparison between a traditional unified-theory and a string-inspired approach to the solution of the many open problems of the Standard Model. We emphasize that viable models must satisfy {\em all} available experimental constraints and be as simple as theoretically possible. The two well defined supergravity models, $SU(5)$ and $SU(5)\times U(1)$, can be described in terms of only a few parameters (five and three respectively) instead of the more than twenty needed in the MSSM model, \ie, the Minimal Supersymmetric extension of the Standard Model. A case of special interest is the strict no-scale $SU(5)\times U(1)$ supergravity where all predictions depend on only one parameter (plus the top-quark mass). A general consequence of these analyses is that supersymmetric particles can be at the verge of discovery, lurking around the corner at present and near future facilities. This review should help anyone distinguish between well motivated predictions and predictions based on arbitrary choices of parameters in undefined models.Comment: 25 pages, Latex, 11 figures (not included), CERN-TH.7077/93, CTP-TAMU-65/93. A complete ps file (1.31MB) with embedded figures is available by request from [email protected]