Cough aerosol in healthy participants: fundamental knowledge to optimize droplet-spread infectious respiratory disease management

<p>Abstract</p> <p>Background</p> <p>The Influenza A H1N1 virus can be transmitted via direct, indirect, and airborne route to non-infected subjects when an infected patient coughs, which expels a number of different sized droplets to the surrounding environment as an aerosol. The objective of the current study was to characterize the human cough aerosol pattern with the aim of developing a standard human cough bioaerosol model for Influenza Pandemic control.</p> <p>Method</p> <p>45 healthy non-smokers participated in the open bench study by giving their best effort cough. A laser diffraction system was used to obtain accurate, time-dependent, quantitative measurements of the size and number of droplets expelled by the cough aerosol.</p> <p>Results</p> <p>Voluntary coughs generated droplets ranging from 0.1 - 900 microns in size. Droplets of less than one-micron size represent 97% of the total number of measured droplets contained in the cough aerosol. Age, sex, weight, height and corporal mass have no statistically significant effect on the aerosol composition in terms of size and number of droplets.</p> <p>Conclusions</p> <p>We have developed a standard human cough aerosol model. We have quantitatively characterized the pattern, size, and number of droplets present in the most important mode of person-to-person transmission of IRD: the cough bioaerosol. Small size droplets (< 1 μm) predominated the total number of droplets expelled when coughing. The cough aerosol is the single source of direct, indirect and/or airborne transmission of respiratory infections like the Influenza A H1N1 virus.</p> <p>Study design</p> <p>Open bench, Observational, Cough, Aerosol study</p

RG flows from Spin(7), CY 4-fold and HK manifolds to AdS, Penrose limits and pp waves

We obtain explicit realizations of holographic renormalization group (RG) flows from M-theory, from E^{2,1} \times Spin(7) at UV to AdS_4 \times \tilde{S^7} (squashed S^7) at IR, from E^{2,1} \times CY4 at UV to AdS_4 \times Q^{1,1,1} at IR, and from E^{2,1} \times HK (hyperKahler) at UV to AdS_4 \times N^{0,1,0} at IR. The dual type IIA string theory configurations correspond to D2-D6 brane systems where D6 branes wrap supersymmetric four-cycles. We also study the Penrose limits and obtain the pp-wave backgrounds for the above configurations. Besides, we study some examples of non-supersymmetric and supersymmetric flows in five-dimensional gauge theories.Comment: 42 pages, 6 eps figures, typos and misprints correcte

The a-theorem and conformal symmetry breaking in holographic RG flows

We study holographic models describing an RG flow between two fixed points driven by a relevant scalar operator. We show how to introduce a spurion field to restore Weyl invariance and compute the anomalous contribution to the generating functional in even dimensional theories. We find that the coefficient of the anomalous term is proportional to the difference of the conformal anomalies of the UV and IR fixed points, as expected from anomaly matching arguments in field theory. For any even dimensions the coefficient is positive as implied by the holographic a-theorem. For flows corresponding to spontaneous breaking of conformal invariance, we also compute the two-point functions of the energy-momentum tensor and the scalar operator and identify the dilaton mode. Surprisingly we find that in the simplest models with just one scalar field there is no dilaton pole in the two-point function of the scalar operator but a stronger singularity. We discuss the possible implications.Comment: 50 pages. v2: minor changes, added references, extended discussion. v3: we have clarified some of the calculations and assumptions, results unchanged. v4: published version in JHE

Scolytinae y Platypodinae (Coleoptera: Curculiondae) de Tabasco, México

The aim of the present study was to evaluate the diversity of Scolytinae and Platypodinae in five localities of Tabasco between December 2012 and April 2013. Ten flight intercept traps were used with ethyl alcohol as an attractant to collect insects in each site. A total of 4,232 specimens were collected from 62 species, of which 57 belong to Scolytinae and five to Platypodinae. The greatest diversity of species was obtained in Malpasito (MP) with a value of H´=2.11 and the lowest in Boca del Cerro (BC) with a value of H´=0.78, the highest species richness was recorded MP with 39 and the highest species abundance Francisco Rueda (FR) with 1,500 specimens. The genera Hypothenemus and Xyleborus presented the highest species richness with 10 and 7 respectively. The species Premnobius cavipennis Eichhoff, Xyleborus volvulus (Fabricius), Sampsonius dampfi Schedl, Hypothenemus interstitialis (Hopkins) and Corthylus papulans Eichhoff showed the highest abundance with 2,962 specimens, representing 69.99% of the total. The especies Cnesinus elegans Blandford, C. gracilis Blandford, Corthylocurus barbatus (Blandford), Chramesus crenatus Wood, H. effeminatus Wood, H. inaequalis Wood, H. columbi Hopkins and M. robustum (Schedl) are new records for Tabasco. The list of species of these insects in Tabasco, México continues to grow as new samples are taken, suggesting that it has not been possible to collect the real diversity supported by the ecosystems of the state.El objetivo del presente estudio fue evaluar la diversidad de Scolytinae y Platypodinae en cinco localidades de Tabasco de diciembre de 2012 y abril de 2013. Se utilizaron diez trampas de intercepción de vuelo con alcohol etílico como atrayente para recolectar a los insectos en cada sitio. Se recolectaron en total 4,232 especímenes de 62 especies, de las cuales 57 pertenecen a Scolytinae y cinco a Platypodinae. La mayor diversidad de especies se obtuvo en Malpasito (MP) con un valor de H´=2.11 y la menor en Boca del cerro (BC) con un valor de H´=0.78, la mayor riqueza de especies la registró MP con 39 y la mayor abundancia Francisco Rueda (FR) con 1,500 especímenes. Los géneros Hypothenemus y Xyleborus presentaron la mayor riqueza de especies con diez y siete respectivamente. Las especies Premnobius cavipennis Eichhoff, Xyleborus volvulus (Fabricius), Sampsonius dampfi Schedl, Hypothenemus interstitialis (Hopkins) y Corthylus papulans Eichhoff registraron la mayor abundancia con 2,962 especímenes, lo que representa el 69.99% del total. Las especies Cnesinus elegans Blandford, C. gracilis Blandford, Corthylocurus barbatus (Blandford), Chramesus crenatus Wood, H. effeminatus Wood, H. inaequalis Wood, H. columbi Hopkins y M. robustum (Schedl) son nuevos registros para Tabasco. La lista de especies de estos insectos en Tabasco, México continúa creciendo conforme se incrementan los muestreos, lo que sugiere que no ha sido posible recolectar la diversidad real que albergan los ecosistemas del estado

Towards multi-scale dynamics on the baryonic branch of Klebanov-Strassler

We construct explicitly a new class of backgrounds in type-IIB supergravity which generalize the baryonic branch of Klebanov-Strassler. We apply a solution-generating technique that, starting from a large class of solutions of the wrapped-D5 system, yields the new solutions, and then proceed to study in detail their properties, both in the IR and in the UV. We propose a simple intuitive field theory interpretation of the rotation procedure and of the meaning of our new solutions within the Papadopoulos-Tseytlin ansatz, in particular in relation to the duality cascade in the Klebanov-Strassler solution. The presence in the field theory of different VEVs for operators of dimensions 2, 3 and 6 suggests that this is an important step towards the construction of the string dual of a genuinely multi-scale (strongly coupled) dynamical model.Comment: 37 pages, 7 figures. References added, version to appear in JHE

Gravity localization in a string-cigar braneworld

We proposed a six dimensional string-like braneworld built from a warped product between a 3-brane and the Hamilton cigar soliton space, the string-cigar braneworld. This transverse manifold is a well-known steady solution of the Ricci flow equation that describes the evolution of a manifold. The resulting bulk is an interior and exterior metric for a thick string. This is a physical and feasible scenario since the source satisfies the dominant energy condition. It is possible to realize the geometric flow as a result of variations of the matter content of the brane, actually, as its tensions. Furthermore, the Ricci flow defines a family of string-like branes and we studied the effects that the evolution of the transverse space has on the geometric and physical quantities. The geometric flow makes the cosmological constant and the relationship between the Planck masses evolves. The gravitational massless mode remains trapped to the brane and the width of the mode depends on the evolution parameter. For the Kaluza-Klein modes, the asymptotic spectrum of mass is the same as for the thin string-like brane and the analogue Schroedinger potential also changes according to the flow.Comment: 20 pages, 6 figures. We include new discussion about gravitational perturbation analysis and some new references. Results unchanged. Version to appear in Classical and Quantum Gravit

Field theory aspects of non-Abelian T-duality and N = 2 linear quivers

In this paper we propose a linear quiver with gauge groups of increasing rank as field theory dual to the AdS 5 background constructed by Sfetsos and Thompson through non-Abelian T-duality. The formalism to study 4d N = 2 SUSY CFTs developed by Gaiotto and Maldacena is essential for our proposal. We point out an interesting relation between (Hopf) Abelian and non-Abelian T-dual backgrounds that allows to see both backgrounds as different limits of a solution constructed by Maldacena and Núñez. This suggests different completions of the long quiver describing the CFT dual to the nonAbelian T-dual background that match different observables

Type IIB supergravity solutions with AdS5 from Abelian and non-Abelian T dualities

We present a large class of new backgrounds that are solutions of type IIB supergravity with a warped AdS${}_5$ factor, non-trivial axion-dilaton, $B$-field and three-form Ramond-Ramond flux but yet have no five-form flux. We obtain these solutions and many of their variations by judiciously applying non-Abelian and Abelian T-dualities, as well as coordinate shifts to AdS${}_5\times X_5$ IIB supergravity solutions with $X_5=S^5, T^{1,1}, Y^{p,q}$. We address a number of issues pertaining to charge quantization in the context of non-Abelian T-duality. We comment on some properties of the expected dual super conformal field theories by studying their CFT central charge holographically. We also use the structure of the supergravity Page charges, central charges and some probe branes to infer aspects of the dual super conformal field theories.Comment: 71 pages, one table. v2: References added, some normalizations corrected, results unchange

Mesons from (non) Abelian T-dual backgrounds

In this work we study mesonic excitations in a Quantum Field Theory dual to the non Abelian T-dual of $AdS_5\times S^5$, using a D6 brane probe on the Sfetsos-Thompson background. Before and after the duality, we observe interesting differences between the spectra and interpret them. The spectrum of masses and the interactions among mesonic excitations teach valuable lessons about the character of non-Abelian T-duality and its implications for Holography. The case of Abelian T-duality is also studied.Comment: 26 pages plus many long appendice

Holographic flows in non-Abelian T-dual geometries

We use non-Abelian T-duality to construct new N=1 solutions of type IIA supergravity (and their M-theory lifts) that interpolate between AdS_5 geometries. We initiate a study of the holographic interpretation of these backgrounds as RG flows between conformal fixed points. Along the way we give an elegant formulation of non-Abelian T-duality when acting on a wide class of backgrounds, including those corresponding to such flows, in terms of their SU(2) structure