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The most common nosocomial fungal infections are caused by several species of Candida, of which Candida glabratais the second most frequently isolated species from bloodstream infections. C. glabratadisplays relatively high minimal inhibitory concentration values (MIC) to the antifungal fluconazole and is associated with high mortality rates. To decrease mortality rates, the appropriate treatment must be administered promptly. C. glabratacontains in its genome several non-identical copies of species-specific sequences. We designed three pairs of C. glabrata-specific primers for endpoint PCR amplification that align to these species-specific sequences and amplify the different copies in the genome. Using these primers, we developed a fast, sensitive, inexpensive, and highly specific PCR-based method to positively detect C. glabrataDNA in a concentration-dependent manner from mixes of purified genomic DNA of several Candidaspecies, as well as from hemocultures and urine clinical samples. This tool can be used for positive identification of C. glabratain the clinic.

Potentiometric sensors based on metal oxides as electrodes and 8YSZ as electrolyte at 550degC can provide selective response to C2H4 with low cross-sensitivity toward CO, H2O, C14H10 and C11H10. The target of the present work is to evaluate the influence of the material used as electrolyte, the electrolyte thickness and the working temperature to check the effect of these parameters on the response to C2H4. After surface functionalization via Ni nanoparticle deposition onto the working electrode to improve the sensor performance, the effect of 8YSZ electrolyte thickness (from 0.1 to 1.2 mm) on the sensor response was studied. The best performance was achieved with the thinner electrolyte (0.1 mm) in terms of selectivity to C2H4 and low cross-sensitivity toward CO. In second place, Ce0.8Gd0.202-d (CGO) and scandium-stabilized zirconia (ScSZ) oxide-ion conductors were tested as an alternative to 8YSZ to operate at lower temperatures. ScSZ and CGO based-devices provided promising sensing performance at 450degC and C2H4 concentrations below 100 ppm in dry conditions upon functionalization of the working electrode with Ni nanoparticles. At 550degC, both electrolyte materials show a selective response to C2H4 with low cross-sensitivity toward CO even in wet conditions or in presence of polyaromatics.

The authors present a review on the recent approaches proposed to implement transversal RF filters. Different tunable transversal filters consisting of wavelength tunable optical taps and those employing the tunability of dispersive devices are presented showing their high-performance characteristics. A comprehensive review of the fundamentals and a discussion on the main limitation of these structures are also included.

We present a theoretical model that describes with great precision the effect of fiber chromatic dispersion over the transfer function of an analog fiber system driven by a Fabry-Perot (FP) semiconductor laser. Experimental results confirm the validity of the developed model. In essence the impact of chromatic dispersion manifests in three ways. First, there is a carrier suppression (or fading) effect that is also present when a single-mode laser is employed. Second, there is a transversal filtering effect owing to the fact that the FP laser modes experience different propagation delays. Third, there is a low-pass effect owing to the linewidth of the longitudinal modes.

We present a complete end-to-end characterization of Gaussian pulse propagation through optical fibers and waveguides with an arbitrary dispersion profile. Our model takes into account the possible chirping of the source and it also encompasses the influence of the source linewidth. We modeled the arbitrary dispersion by taking as much of the coefficients from the Taylor series representing the fiber and waveguide propagation constant as desired. The model is used to study the impact of higher-order dispersion terms in the propagated pulse shape and rms time width. Also outlined are applications to the calculation of capacity limits in optical communications systems limited by high-order dispersion terms and to other fields such as the calculation of aberrations in temporal imaging systems and spatial diffraction.

We provide a theoretical (signal and noise) and an experimental characterization of the nonrecirculating and the recirculating fiber-optic delay-line filters that include one fiber loop. Signal and noise analysis for passive and active operation are presented, and measurements of both the filter modulus and the phase are presented, showing good agreement with results predicted by the theory.

In this paper we focus on integrated resonators that employ electro-optical couplers and phase shifters and, thus, are capable of providing high-speed channel tunability and coupling constant variation. We find that, although a conventional operation is always attainable, integrated resonators can, in some cases, present an anomalous behavior compared to that of their fiber-based equivalents. These can have potential applications.

We have experimentally demonstrated a new optical signal processor based on the use of arrayed waveguide gratings. The structure exploits the concept of spectral slicing combined with the use of an optical dispersive medium. The approach presents increased flexibility from previous slicing-based structures in terms of tunability, reconfiguration, and apodization of the samples or coefficients of the transversal optical filter.

We report on a novel technical approach to the implementation of photonic rf filters that is based on the π phase inversion that a rf modulating signal suffers in an electro-optic Mach–Zehnder modulator, which depends on whether the positive or the negative linear slope of the signal’s modulation transfer function is employed. Experimental evidence is provided of the implementation of filters with negative coefficients that shows excellent agreement with results predicted by the theory.

We present a novel device, an arrayed waveguide Sagnac interferometer, that combines the flexibility of arrayed waveguides and the wide application range of fiber or integrated optics Sagnac loops. We form the device by closing an array of wavelength-selective light paths provided by two arrayed waveguides with a single 2×2 coupler in a Sagnac configuration. The equations that describe the device’s operation in general conditions are derived. A preliminary experimental demonstration is provided of a fiber prototype in passive operation that shows good agreement with the expected theoretical performance. Potential applications of the device in nonlinear operation are outlined and discussed.

Potentiometric sensors based on metal oxides as electrodes and 8YSZ as electrolyte at 550°C can provide selective response to C2H4with low cross-sensitivity toward CO, H2O, C14H10and C11H10. The target of the present work is to evaluate the influence of the material used as electrolyte, the electrolyte thickness and the working temperature to check the effect of these parameters on the response to C2H4. After surface functionalization via Ni nanoparticle deposition onto the working electrode to improve the sensor performance, the effect of 8YSZ electrolyte thickness (from 0.1 to 1.2 mm) on the sensor response was studied. The best performance was achieved with the thinner electrolyte (0.1 mm) in terms of selectivity to C2H4and low cross-sensitivity toward CO. In second place, Ce0.8Gd0.202-δ(CGO) and scandium-stabilized zirconia (ScSZ) oxide-ion conductors were tested as an alternative to 8YSZ to operate at lower temperatures. ScSZ and CGO based-devices provided promising sensing performance at 450°C and C2H4concentrations below 100 ppm in dry conditions upon functionalization of the working electrode with Ni nanoparticles. At 550°C, both electrolyte materials show a selective response to C2H4with low cross-sensitivity toward CO even in wet conditions or in presence of polyaromatics.

No relevant conflicts of interest to declare.

Long-term quiescence or dormancy preserves the genomic integrity as well as the long-term self-renewal and functional capacities of hematopoietic stem cells (HSCs) during homeostasis. In response to infections, inflammatory or chemotherapy induced stress, dormant HSCs (dHSCs) become reversibly activated and are critical for the re-establishment of homeostasis. In our previous work, we defined the molecular landscape of HSCs and its immediate progenitors by determining their DNA-methylome, RNA- transcriptome and their proteome (Cabezas-Wallscheid et al., Cell Stem Cell2014). This revealed the vitamin A/retinoic acid (RA) signaling pathway to be molecularly predominantly enriched in HSCs. However, the functional relevance of dietary vitamin A for maintenance of HSCs remains uncertain. Moreover, the molecular identity of very rare dHSCs as well as the mechanism regulating their maintenance or the transition out and back into dormancy remains unknown.