Time-lapse ultrashort pulse microscopy of infection in three-dimensional versus two-dimensional culture environments reveals enhanced extra-chromosomal virus replication compartment formation

The mechanisms that enable viruses to harness cellular machinery for their own survival are primarily studied in cell lines cultured in two-dimensional (2-D) environments. However, there are increasing reports of biological differences between cells cultured in 2-D versus three-dimensional (3-D) environments. Here we report differences in host-virus interactions based on differences in culture environment. Using ultrashort pulse microscopy (UPM), a form of two-photon microscopy that utilizes sub-10-fs pulses to efficiently excite fluorophores, we have shown that de novo development of extra-chromosomal virus replication compartments (VRCs) upon murine cytomegalovirus (mCMV) infection is markedly enhanced when host cells are cultured in 3-D collagen gels versus 2-D monolayers. In addition, time-lapse imaging revealed that mCMV-induced VRCs have the capacity to grow by coalescence. This work supports the future potential of 3-D culture as a useful bridge between traditional monolayer cultures and animal models to study host-virus interactions in a more physiologically relevant environment for the development of effective anti-viral therapeutics. These advances will require broader adoption of modalities, such as UPM, to image deep within scattering tissues

Texture analysis in gel electrophoresis images using an integrative kernel-based approach

[Abstract] Texture information could be used in proteomics to improve the quality of the image analysis of proteins separated on a gel. In order to evaluate the best technique to identify relevant textures, we use several different kernel-based machine learning techniques to classify proteins in 2-DE images into spot and noise. We evaluate the classification accuracy of each of these techniques with proteins extracted from ten 2-DE images of different types of tissues and different experimental conditions. We found that the best classification model was FSMKL, a data integration method using multiple kernel learning, which achieved AUROC values above 95% while using a reduced number of features. This technique allows us to increment the interpretability of the complex combinations of textures and to weight the importance of each particular feature in the final model. In particular the Inverse Difference Moment exhibited the highest discriminating power. A higher value can be associated with an homogeneous structure as this feature describes the homogeneity; the larger the value, the more symmetric. The final model is performed by the combination of different groups of textural features. Here we demonstrated the feasibility of combining different groups of textures in 2-DE image analysis for spot detection.Instituto de Salud Carlos III; PI13/00280United Kingdom. Medical Research Council; G10000427, MC_UU_12013/8Galicia. Consellería de Economía e Industria; 10SIN105004P

Constraints for the nuclear parton distributions from Z and W production at the LHC

The LHC is foreseen to finally bring also the nuclear collisions to the TeV scale thereby providing new possibilities for physics studies, in particular related to the electro-weak sector of the Standard Model. We study here the Z and W production in proton-lead and lead-lead collisions at the LHC, concentrating on the prospects of testing the factorization and constraining the nuclear modifications of the parton distribution functions (PDFs). Especially, we find that the rapidity asymmetries in proton-nucleus collisions, arising from the differences in the PDFs between the colliding objects, provide a decisive advantage in comparison to the rapidity-symmetric nucleus-nucleus case. We comment on how such studies will help to improve our knowledge of the nuclear PDFs.Comment: The version accepted for publication in JHEP. New figures has been added, and we also discuss the single charged lepton productio

Asymptotically anti-de Sitter wormholes

Starting with a procedure for dealing with general asymptotic behaviors, we construct a quantum theory for asymptotically anti-de Sitter wormholes. We follow both the path integral formalism and the algebraic quantization program proposed by Ashtekar. By adding suitable surface terms, the Euclidean action of the asymptoically anti-de Sitter wormholes can be seen to be finite and gauge invariant. This action determines an appropriate variational problem for wormholes. We also obtain the wormhole wave functions of the gravitational model and show that all the physical states of the quantum theory are superpositions of wormhole states.Comment: 10 pages, RevTeX 3.0, LaTeX 2.0

LHC Discovery Potential for Non-Standard Higgs Bosons in the 3b Channel

In a variety of well motivated models, such as two Higgs Doublet Models (2HDMs) and the Minimal Supersymmetric Standard Model (MSSM), there are neutral Higgs bosons that have significantly enhanced couplings to b-quarks and tau leptons in comparison to those of the SM Higgs. These so called non-standard Higgs bosons could be copiously produced at the LHC in association with b quarks, and subsequently decay into b-quark pairs. However, this production channel suffers from large irreducible QCD backgrounds. We propose a new search strategy for non-standard neutral Higgs bosons at the 7 TeV LHC in the 3b's final state topology. We perform a simulation of the signal and backgrounds, using state of the art tools and methods for different sets of selection cuts, and conclude that neutral Higgs bosons with couplings to b-quarks of about 0.3 or larger, and masses up to 400 GeV, could be seen with a luminosity of 30 fb^{-1}. In the case of the MSSM we also discuss the complementarity between the 3b channel and the inclusive tau pair channel in exploring the supersymmetric parameter space.Comment: 14 pages, 3 figures, 4 tables, references added, published versio

USO DE TRES MÉTODOS PARA EVALUAR EL MANATI AMAZÓNICO (Trichechus inunguis) EN EL ÁREA DE CONSERVACIÓN REGIONAL TAMSHIYACU TAHUAYO, LORETO, PERÚ

The Amazon manatee (Trichechus inunguis) is endemic to the Amazon Basin, with limited information on population dynamics and currently listed as Vulnerable by the Red List of the International Union for the Conservation of Nature (IUCN). The aim of this study was to compare three methodologies: visual detection (VD), side scan sonar technology (SBL), and surveys to local communities; to detect the presence of the Amazonian manatee and assess the use of these methods for future studies along the species distribution range. The study was carried out within the Tamshiyacu Tahuayo Communal Regional Conservation Areain Iquitos, Peru. The VD resulted in zero sightings at both seasons after a sampling effort of 30 and 29 hours during the rainy and dry seasons respectively. After using the SBL, two individuals were recorded in August, after a total sampling of 103.38 km in the dry season (0.02 ind/km). Surveys to artisanal fishermen in three neighboring communities indicated the presence of manatees and the perception of reduction in sightings within the protected area during 2018 (previous year of this study). We discussed the advantages and disadvantages of each methodology, the logistics associated with its use in complex habitats, and its effectiveness and potential use to detect manatees in future studies in the area.El manatı́ amazónico (Trichechus inunguis) es endémico de la cuenca amazónica, cuenta con una limitada información de dinámica poblacional y actualmente está categorizado como Vulnerable por la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza (UICN). El presente estudio tiene como objetivo comparar tres metodologıá s: registro visual (RV), sonar de barrido lateral (SBL) y encuestas en comunidades locales; para detectar la presencia de la especie y evaluar su aplicación para futuros estudios en su zona de distribución. El estudio fue llevado a cabo dentro del Área de Conservación Regional Comunal Tamshiyacu Tahuayo en Iquitos, Perú. El RV resultó en cero avistamientos en ambas estaciones luego de un esfuerzo de muestreo de 30 y 29 horas en la estación creciente y vaciante respectivamente. Tras el uso del SBL, dos individuos se registraron en agosto, luego de un recorrido total de 103,38 km en la estación vaciante (0,02 ind/km). Las encuestas realizadas a los pescadores artesanales en tres comunidades aledañas indicaron lapresencia de la especie, ası́ como la percepción de una reducción en avistamientos en el área protegida durante el 2018 (año previo a las encuestas).Se discute las ven‑ tajas y desventajas de cada metodología , la logística asociada a su uso en hábitats complejos, y su efectividad y uso potencial para la detección de manatíes en futuros estudios en la zon

String Theory and Inflation

String theory abounds with light scalar fields (the dilaton and various moduli) which create a host of observational problems, and notably some serious cosmological difficulties similar to the ones associated with the Polonyi field in the earliest versions of spontaneously broken supergravity. We show that all these problems are naturally avoided if a recently introduced mechanism for fixing the vacuum expectation values of the dilaton and/or moduli is at work. We study both the classical evolution and the quantum fluctuations of such scalar fields during a primordial inflationary era and find that the results are naturally compatible with observational facts. In this model, dilatons or moduli within a very wide range of masses (which includes the SUSY-breaking favored 1 TeV value and extends up to the Planck scale) qualify to define a novel type of essentially stable ultra-weakly interacting massive particles able to provide enough mass density to close the universeComment: 25 page

On Applications of Campbell's Embedding Theorem

A little known theorem due to Campbell is employed to establish the local embedding of a wide class of 4-dimensional spacetimes in 5-dimensional Ricci-flat spaces. An embedding for the class of n-dimensional Einstein spaces is also found. The local nature of Campbell's theorem is highlighted by studying the embedding of some lower-dimensional spaces.Comment: 17 pages, standard Latex sourc