Single grain heating due to inelastic cotunneling

We study heating effects of a single metallic quantum dot weakly coupled to two leads. The dominant mechanism for heating at low temperatures is due to inelastic electron cotunneling processes. We calculate the grain temperature profile as a function of grain parameters, bias voltage, and time and show that for nanoscale size grains the heating effects are pronounced and easily measurable in experiments.Comment: 4 pages, 3 figures, revtex4, extended and corrected versio

Deterministic nano-assembly of a coupled quantum emitter - photonic crystal cavity system

The interaction of a single quantum emitter with its environment is a central theme in quantum optics. When placed in highly confined optical fields, such as those created in optical cavities or plasmonic structures, the optical properties of the emitter can change drastically. In particular, photonic crystal (PC) cavities show high quality factors combined with an extremely small mode volume. Efficiently coupling a single quantum emitter to a PC cavity is challenging because of the required positioning accuracy. Here, we demonstrate deterministic coupling of single Nitrogen-Vacancy (NV) centers to high-quality gallium phosphide PC cavities, by deterministically positioning their 50 nm-sized host nanocrystals into the cavity mode maximum with few-nanometer accuracy. The coupling results in a 25-fold enhancement of NV center emission at the cavity wavelength. With this technique, the NV center photoluminescence spectrum can be reshaped allowing for efficient generation of coherent photons, providing new opportunities for quantum science.Comment: 13 pages, 4 figure

Single and coupled L3 photonic crystal cavities for cavity-QED experiments

Here we discuss the experimental characterization of the spatial far-field profiles for the confined modes in a photonic crystal cavity of the L3 type, finding a good agreement with FDTD simulations. We then link the far-field profiles to relevant features of the cavity mode near-fields, using a simple Fabry-Perot resonator model. Finally, we describe a technique for independent all-electrical control of the wavelength of quantum dots in separated L3 cavities, coupled by a waveguide, by electrical isolation via proton implantation

Analysis of phylogeny, distribution, and pathogenicity of Botryosphaeriaceae species associated with gummosis of Anacardium in Brazil, with a new species of Lasiodiplodia.

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Mitochondrial dysfunction in sepsis is associated with diminished intramitochondrial TFAM despite its increased cellular expression

Sepsis is characterized by a dysregulated immune response, metabolic derangements and bioenergetic failure. These alterations are closely associated with a profound and persisting mitochondrial dysfunction. This however occurs despite increased expression of the nuclear-encoded transcription factor A (TFAM) that normally supports mitochondrial biogenesis and functional recovery. Since this paradox may relate to an altered intracellular distribution of TFAM in sepsis, we tested the hypothesis that enhanced extramitochondrial TFAM expression does not translate into increased intramitochondrial TFAM abundance. Accordingly, we prospectively analyzed PBMCs both from septic patients (n = 10) and lipopolysaccharide stimulated PBMCs from healthy volunteers (n = 20). Extramitochondrial TFAM protein expression in sepsis patients was 1.8-fold greater compared to controls (p = 0.001), whereas intramitochondrial TFAM abundance was approximate 80% less (p < 0.001). This was accompanied by lower mitochondrial DNA copy numbers (p < 0.001), mtND1 expression (p < 0.001) and cellular ATP content (p < 0.001) in sepsis patients. These findings were mirrored in lipopolysaccharide stimulated PBMCs taken from healthy volunteers. Furthermore, TFAM-TFB2M protein interaction within the human mitochondrial core transcription initiation complex, was 74% lower in septic patients (p < 0.001). In conclusion, our findings, which demonstrate a diminished mitochondrial TFAM abundance in sepsis and endotoxemia, may help to explain the paradox of lacking bioenergetic recovery despite enhanced TFAM expression

Complete Genome Sequence of the Plant-Pathogenic Fungus Colletotrichum lupini

Colletotrichum is a fungal genus (Ascomycota, Sordariomycetes, Glomerellaceae) that includes many economically important plant pathogens that cause devastating diseases of a wide range of plants. In this work, using a combination of long- and short-read sequencing technologies, we sequenced the genome of Colletotrichum lupini RB221, isolated from white lupin (Lupinus albus) in France during a survey in 2014. The genome was assembled into 11 nuclear chromosomes and a mitochondrial genome with a total assembly size of 63.41 Mb and 36.55 kb, respectively. In total, 18,324 protein-encoding genes have been predicted, of which only 39 are specific to C. lupini. This resource will provide insight into pathogenicity factors and will help provide a better understanding of the evolution and genome structure of this important plant pathogen

H3K9me-Independent Gene Silencing in Fission Yeast Heterochromatin by Clr5 and Histone Deacetylases

Nucleosomes in heterochromatic regions bear histone modifications that distinguish them from euchromatic nucleosomes. Among those, histone H3 lysine 9 methylation (H3K9me) and hypoacetylation have been evolutionarily conserved and are found in both multicellular eukaryotes and single-cell model organisms such as fission yeast. In spite of numerous studies, the relative contributions of the various heterochromatic histone marks to the properties of heterochromatin remain largely undefined. Here, we report that silencing of the fission yeast mating-type cassettes, which are located in a well-characterized heterochromatic region, is hardly affected in cells lacking the H3K9 methyltransferase Clr4. We document the existence of a pathway parallel to H3K9me ensuring gene repression in the absence of Clr4 and identify a silencing factor central to this pathway, Clr5. We find that Clr5 controls gene expression at multiple chromosomal locations in addition to affecting the mating-type region. The histone deacetylase Clr6 acts in the same pathway as Clr5, at least for its effects in the mating-type region, and on a subset of other targets, notably a region recently found to be prone to neo-centromere formation. The genomic targets of Clr5 also include Ste11, a master regulator of sexual differentiation. Hence Clr5, like the multi-functional Atf1 transcription factor which also modulates chromatin structure in the mating-type region, controls sexual differentiation and genome integrity at several levels. Globally, our results point to histone deacetylases as prominent repressors of gene expression in fission yeast heterochromatin. These deacetylases can act in concert with, or independently of, the widely studied H3K9me mark to influence gene silencing at heterochromatic loci

Optical Properties of Deep Ice at the South Pole - Absorption

We discuss recent measurements of the wavelength-dependent absorption coefficients in deep South Pole ice. The method uses transit time distributions of pulses from a variable-frequency laser sent between emitters and receivers embedded in the ice. At depths of 800 to 1000 m scattering is dominated by residual air bubbles, whereas absorption occurs both in ice itself and in insoluble impurities. The absorption coefficient increases approximately exponentially with wavelength in the measured interval 410 to 610 nm. At the shortest wavelength our value is about a factor 20 below previous values obtained for laboratory ice and lake ice; with increasing wavelength the discrepancy with previous measurements decreases. At around 415 to 500 nm the experimental uncertainties are small enough for us to resolve an extrinsic contribution to absorption in ice: submicron dust particles contribute by an amount that increases with depth and corresponds well with the expected increase seen near the Last Glacial Maximum in Vostok and Dome C ice cores. The laser pulse method allows remote mapping of gross structure in dust concentration as a function of depth in glacial ice.Comment: 26 pages, LaTex, Accepted for publication in Applied Optics. 9 figures, not included, available on request from [email protected]