Type I interferons in tuberculosis: Foe and occasionally friend

Tuberculosis remains one of the leading causes of mortality worldwide, and, despite its clinical significance, there are still significant gaps in our understanding of pathogenic and protective mechanisms triggered by Mycobacterium tuberculosis infection. Type I interferons (IFN) regulate a broad family of genes that either stimulate or inhibit immune function, having both host-protective and detrimental effects, and exhibit well-characterized antiviral activity. Transcriptional studies have uncovered a potential deleterious role for type I IFN in active tuberculosis. Since then, additional studies in human tuberculosis and experimental mouse models of M. tuberculosis infection support the concept that type I IFN promotes both bacterial expansion and disease pathogenesis. More recently, studies in a different setting have suggested a putative protective role for type I IFN. In this study, we discuss the mechanistic and contextual factors that determine the detrimental versus beneficial outcomes of type I IFN induction during M. tuberculosis infection, from human disease to experimental mouse models of tuberculosis

Performance of dynamical decoupling in bosonic environments and under pulse-timing fluctuations

We study the suppression of qubit dephasing through Uhrig dynamical decoupling (UDD) in nontrivial environments modeled within the spin-boson formalism. In particular, we address the case of (i) a qubit coupled to a bosonic bath with power-law spectral density, and (ii) a qubit coupled to a single harmonic oscillator that dissipates energy into a bosonic bath, which embodies an example of a structured bath for the qubit. We then model the influence of random time jitter in the UDD protocol by sorting pulse-application times from Gaussian distributions centered at appropriate values dictated by the optimal protocol. In case (i) we find that, when few pulses are applied and a sharp cutoff is considered, longer coherence times and robust UDD performances (against random timing errors) are achieved for a super-Ohmic bath. On the other hand, when an exponential cutoff is considered a super-Ohmic bath is undesirable. In case (ii) the best scenario is obtained for an overdamped harmonic motion. Our study provides relevant information for the implementation of optimized schemes for the protection of quantum states from decoherence.Comment: 8 pages, 5 figure

Atomic jet from SMM1 (FIRS1) in Serpens uncovers non-coeval binary companion

We report on the detection of an atomic jet associated with the protostellar source SMM1 (FIRS1) in Serpens. The jet is revealed in [FeII] and [NeII] line maps observed with Spitzer/IRS, and further confirmed in HiRes IRAC and MIPS images. It is traced very close to SMM1 and peaks at ~5 arcsec" from the source at a position angle of $\sim 125 degrees. In contrast, molecular hydrogen emission becomes prominent at distances > 5" from the protostar and extends at a position angle of 160 degrees. The morphological differences suggest that the atomic emission arises from a companion source, lying in the foreground of the envelope surrounding the embedded protostar SMM1. In addition the molecular and atomic Spitzer maps disentangle the large scale CO (3-2) emission observed in the region into two distinct bipolar outflows, giving further support to a proto-binary source setup. Analysis at the peaks of the [FeII] jet show that emission arises from warm and dense gas (T ~1000 K, n(electron) 10^5 - 10^6 cm^-3). The mass flux of the jet derived independently for the [FeII] and [NeII] lines is 10^7 M(sun)/yr, pointing to a more evolved Class~I/II protostar as the driving source. All existing evidence converge to the conclusion that SMM1 is a non-coeval proto-binary source.Comment: 10 pages, 7 figures, 1 table. Accepted for publication in Astronomy \& Astrophysic

The ionizing sources of luminous compact HII regions in the RCW106 and RCW122 clouds

Given the rarity of young O star candidates, compact HII regions embedded in dense molecular cores continue to serve as potential sites to peer into the details of high-mass star formation. To uncover the ionizing sources of the most luminous and compact HII regions embedded in the RCW106 and RCW122 giant molecular clouds, known to be relatively nearby (2-4 kpc) and isolated, thus providing an opportunity to examine spatial scales of a few hundred to a thousand AU in size. High spatial resolution (0.3"), mid-infrared spectra (R=350), including the fine structure lines [ArIII] and [NeII], were obtained for four luminous compact HII regions, embedded inside the dense cores within the RCW106 and RCW122 molecular cloud complexes. At this resolution, these targets reveal point-like sources surrounded by nebulosity of different morphologies, uncovering details at spatial dimensions of <1000AU. The point-like sources display [ArIII] and [NeII] lines - the ratios of which are used to estimate the temperature of the embedded sources. The derived temperatures are indicative of mid-late O type objects for all the sources with [ArIII] emission. Previously known characteristics of these targets from the literature, including evidence of disk or accretion suggest that the identified sources may grow more to become early-type O stars by the end of the star formation process

Micropropagation of a recalcitrant pine (Pinus pinea L.): An overview of the effects of ectomycorrhizal inoculation

Stone pine (Pinus pinea L.) is an economically important forest species in some regions of Iberian Peninsula. Portugal and Spain have nearly 500,000 ha of stone pine stands, representing 85% of worldwide distribution. The main use of this species is for the production of seeds (pinion) for food industry. In addition to its enormous profitability as a producer of seeds, it has beneficial impact on soil protection, dunes fixation and is a pioneer species particularly for cork and holm oaks degraded ecosystems. Stone pine plantations are today a major source of income for forestry holdings. Investments have targeted breeding, reforestation, forest management and harvesting. The maternal inheritance of desirable characteristics such as cone weight, number of seeds per cone and seed length is considerably high in this species thus encouraging the selection of seeds from “plus” trees. The selected trees have been propagated by grafting and micropropagation. However, grafting generates high variability due to scion-rootstock interaction that varies production levels. The production of clonal plants from selected seeds by micropropagation techniques has advanced very slowly due to the recalcitrance of this species in tissue culture and particularly to adventitious rooting of microshoots. Due to the tremendous importance of developing a reproducible tissue culture method for clonal propagation, a study has been carried out for over a decade to enhance rooting and acclimation. During this period of time, continuous increments in the multiplication rate and rooting frequency were achieved by introducing variations in culture media composition and conditions. Auxins, carbohydrates, light quality and duration, temperature at different concentrations and levels as well as compounds such as coumarin; salicylic acid, polyamines, etc. were tested for induction and expression phases of adventitious rooting. Despite these efforts, microshoots regenerated through organogenesis from mature embryo cotyledons failed to root or to have sustained root growth. At this point, an in vitro co-culture technique of stone pine microshoots with ectomycorrhizal-fungi was introduced to overcome the adventitious root growth cessation in vitro and improve root development during acclimation phase. An overview of the results showing the positive effect of fungal inoculation in promoting root growth in vitro and on plantlet survival during acclimation will be presented. Preliminary results of biochemical signals between Pinus pinea/Pisolithus arhizus during early steps of in vitro culture detected by liquid chromatography-mass spectrometry that might be responsible for the positive effect on root growth will be also presented

Direct Type I IFN but Not MDA5/TLR3 Activation of Dendritic Cells Is Required for Maturation and Metabolic Shift to Glycolysis after Poly IC Stimulation

Type I interferons (IFNs) play an important role in direct antiviral defense as well as linking the innate and adaptive immune responses. On dendritic cells (DCs), IFNs facilitate their activation and contribute to CD8+ and CD4+ T cell priming. However, the precise molecular mechanism by which IFNs regulate maturation and immunogenicity of DCs in vivo has not been studied in depth. Here we show that, after in vivo stimulation with the TLR ligand poly IC, IFNs dominate transcriptional changes in DCs. In contrast to direct TLR3/mda5 signaling, IFNs are required for upregulation of all pathways associated with DC immunogenicity. In addition, metabolic pathways, particularly the switch from oxidative phosphorylation to glycolysis, are also regulated by IFNs and required for DC maturation. These data provide evidence for a metabolic reprogramming concomitant with DC maturation and offer a novel mechanism by which IFNs modulate DC maturation

Transient analysis of spectrally asymmetric magnetic photonic crystals with ferromagnetic losses

We analyze transient electromagnetic pulse propagation in spectrally asymmetric magnetic photonic crystals (MPCs) with ferromagnetic losses. MPCs are dispersion-engineered materials consisting of a periodic arrangement of misaligned anisotropic dielectric and ferromagnetic layers that exhibit a stationary inflection point in the (asymmetric) dispersion diagram and unidirectional frozen modes. The analysis is performed via a late-time stable finite-difference time-domain method (FDTD) implemented with perfectly matched layer (PML) absorbing boundary conditions, and extended to handle (simultaneously) dispersive and anisotropic media. The proposed PML-FDTD algorithm is based on a D-H and B-E combined field approach that naturally decouples the FDTD update into two steps, one involving the (anisotropic and dispersive) constitutive material tensors and the other involving Maxwell’s equations in a complex coordinate space (to incorporate the PML). For ferromagnetic layers, a fully dispersive modeling of the permeability tensor is implemented to include magnetic losses in a consistent fashion. The numerical results illustrate some striking properties of MPCs, such as wave slowdown (frozen modes), amplitude increase (pulse compression), and unidirectional characteristics. The numerical model is also used to investigate the sensitivity of the MPC response against excitation (frequency and bandwidth), material (ferromagnetic losses), and geometric (layer misalignment and thickness) parameter variations