A Molecule‐Based Single‐Photon Source Applied in Quantum Radiometry

Single photon sources (SPSs) based on quantum emitters hold promise in quantum radiometry as metrology standard for photon fluxes at the low light level. Ideally this requires control over the photon flux in a wide dynamic range, sub-Poissonian photon statistics and narrow-band emission spectrum. In this work, a monochromatic single-photon source based on an organic dye molecule is presented, whose photon flux is traceably measured to be adjustable between 144 000 and 1320 000 photons per second at a wavelength of (785.6 +/- 0.1) nm, corresponding to an optical radiant flux between 36.5 fW and 334 fW. The high purity of the single-photon stream is verified, with a second-order autocorrelation function at zero time delay below 0.1 throughout the whole range. Featuring an appropriate combination of emission properties, the molecular SPS shows here application in the calibration of a silicon Single-Photon Avalanche Detector (SPAD) against a low-noise analog silicon photodiode traceable to the primary standard for optical radiant flux (i.e. the cryogenic radiometer). Due to the narrow bandwidth of the source, corrections to the SPAD detection efficiency arising from the spectral power distribution are negligible. With this major advantage, the developed device may finally realize a low-photon-flux standard source for quantum radiometry

Response of vine leaf water potential to quick variation in canopy exposure. Example of canopy opening manipulation of Merlot (<em>Vitis vinifera</em> L.)

Plants are in general subject to rapid fluctuations in the environment, particularly as regards the interception of light and therefore water regime. It is important to know the duration and the amplitude of response of the water regime (first leaf water potential) when light interception changes suddenly under natural conditions. widely planted grape variety in the world) was chosen mainly because it offers convenient possibilities of canopy manipulation, ranging from an open and exposed type architecture, to a closed and shaded configurations simply by moving inside or outside a «foldable Lyre» type trellis. Leaf water potential was measured throughout particular days corresponding to stable or variable controlled conditions. The experimental design was an Ecotron in which it is possible to control water and mineral supply and the levels of light interception by plants which have normal development and are growing under natural environmental conditions. The most significant results that emerged from this study are that leaf water potential reacts quickly to any change of light interception, and above all, that the response is almost instantaneous - occurring within few minutes - when transpiration demand decreases, and is significantly longer when the transpiration demand increases, even if the water supply corresponds to maximum transpiration conditions. This shows that the grapevine has a general regulatory system which encourages the plant to economise water even if the supply is sufficient. This could indicate the existence of an overall plant regulatory system - mediated via the water potential - which is important for the coherence of the plant’s physiology and which is quite independent of the environment. From a general point of view, this would confirm the existence of biological triptych network with a superimposed regulatory element (CARBONNEAU, 1996 ; CARBONNEAU and DELOIRE, 2001)

20 Oral Communications EMBnet.journal 18.B Rational design of organelle compartments in cells

In recent years there is a growing interest in researching on mitochondria, chloroplasts and other mitochondrion-like organelles (e.g. hydrogenosomes, mitosomes and apicoplasts) because of the integrate bio-search for comorbidities-related genes, pathway dysfunctions, the energy balance in aging, inflammation and disease, and the discovery of novel factors involved in organelle division, movement, signaling and adaptation to varying environmental and pathogenic conditions. Furthermore, there is an impressive amount of mitochondria and chloroplasts sequence data (thousands of mitochondrial sequences from many species have been sequenced) that hav

Multi-Target Analysis and Design of Mitochondrial Metabolism.

Analyzing and optimizing biological models is often identified as a research priority in biomedical engineering. An important feature of a model should be the ability to find the best condition in which an organism has to be grown in order to reach specific optimal output values chosen by the researcher. In this work, we take into account a mitochondrial model analyzed with flux-balance analysis. The optimal design and assessment of these models is achieved through single- and/or multi-objective optimization techniques driven by epsilon-dominance and identifiability analysis. Our optimization algorithm searches for the values of the flux rates that optimize multiple cellular functions simultaneously. The optimization of the fluxes of the metabolic network includes not only input fluxes, but also internal fluxes. A faster convergence process with robust candidate solutions is permitted by a relaxed Pareto dominance, regulating the granularity of the approximation of the desired Pareto front. We find that the maximum ATP production is linked to a total consumption of NADH, and reaching the maximum amount of NADH leads to an increasing request of NADH from the external environment. Furthermore, the identifiability analysis characterizes the type and the stage of three monogenic diseases. Finally, we propose a new methodology to extend any constraint-based model using protein abundances.PL has received funding from (FP7-Health-F5-2012) under grant agreement no. 305280 (MIMOmics). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.This is the final version of the article. It first appeared from PLoS via http://dx.doi.org/10.1371/journal.pone.013382

Fragmentation mechanisms revealed trough the ash morphology and texture at Sakurajima volcano (Japan)

Volcanic ash represents a fundamental source of information on eruptive processes occurring both prior and after explosive eruptions. In particular, many studies evidenced how volcanic ash can be used to extract unique information about the style of volcanic activity and the relative fragmentation processes. We present a detailed study of ash collected during classical vulcanian activity at Sakurajima volcano (Japan), aimed at investigating the relationships between eruption dynamics and the key features of the resulting volcanic ash (e.g. shape and texture). Information about fragmentation mechanism is revealed by a comprehensive investigation over a complete sequence of activity observed in summer 2013 and October 2014. Based on SEM imaging of the ash samples, 4 main categories (Blocky Irregular, Blocky Regular, Rough-Vesicular, and Rough) have been defined. These characterize all the different phases observed in the eruptive activity, without showing important changes in concentration or morphology. The ash morphology has been then quantitatively defined trough a set of shape parameters, and compared with textural features (ground mass crystallinity, vesicularity) in order to outline the relations with different styles of activity observed during the whole sequence. An exhaustive quantitative dataset on the shape and textural variability of Sakurajima ash provide important insights into magma fragmentation mechanisms and their relations with the evolution of eruptive dynamics. S01.2

Computing with Metabolic Machines

If Turing were a first-year graduate student interested in computers, he would probably migrate into the field of computational biology. During his studies, he presented a work about a mathematical and computational model of the morphogenesis process, in which chemical substances react together. Moreover, a protein can be thought of as a computational element, i.e. a processing unit, able to transform an input into an output signal. Thus, in a biochemical pathway, an enzyme reads the amount of reactants (substrates) and converts them in products. In this work, we consider the biochemical pathway in unicellular organisms (e.g. bacteria) as a living computer, and we are able to program it in order to obtain desired outputs. The genome sequence is thought of as an executable code specified by a set of commands in a sort of ad-hoc low-level programming language. Each combination of genes is coded as a string of bits y ∈ {0, 1} L, each of which represents a gene set. By turning off a gene set, we turn off the chemical reaction associated with it. Through an optimal executable code stored in the “memory ” of bacteria, we are able to simultaneously maximise the concentration of two or more metabolites of interest. Finally, we use the Robustness Analysis and a new Sensitivity Analysis method to investigate both the fragility of the computation carried out by bacteria and the most important entities in the mathematical relations used to model them. 1 Introduction: From Turin

Coupled Electric and Hydraulic Control of a PRS Turbine in a Real Transport Water Network

Although many devices have recently been proposed for pressure regulation and energy harvesting in water distribution and transport networks, very few applications are still documented in the scientific literature. A new in-line Banki turbine with positive outflow pressure and a mobile regulating flap, named PRS, was installed and tested in a real water transport network for pressure and discharge regulation. The PRS turbine was directly connected to a 55 kW asynchronous generator with variable rotational velocity, coupled to an inverter. The start-up tests showed how automatic adjustment of the flap position and the impeller velocity variation are able to change the characteristic curve of the PRS according to the flow delivered by the water manager or to the pressure set-point assigned downstream or upstream of the system, still keeping good efficiency values in hydropower production

Cold and Hot Spots: from Inhibition to Enhancement by Nanoscale Phase Tuning of Optical Nanoantennas

Optical nanoantennas are well-known for the confinement of light into nanoscale hot spots, suitable for emission enhancement and sensing applications. Here, we show how control of the antenna dimensions allows tuning the local optical phase, hence turning a hot spot into a cold spot. We manipulate the local intensity exploiting the interference between driving and scattered field. Using single molecules as local detectors, we experimentally show the creation of subwavelength pockets with full suppression of the driving field. Remarkably, together with the cold excitation spots, we observe inhibition of emission by the phase-tuned nanoantenna. The fluorescence lifetime of a molecule scanned in such volumes becomes longer, showing slow down of spontaneous decay. In conclusion, the spatial phase of a nanoantenna is a powerful knob to tune between enhancement and inhibition in a 3-dimensional subwavelength volume.Peer ReviewedPostprint (author's final draft

Hamman’s syndrome: a case report of spontaneous pneumomediastinum after vaginal delivery

Spontaneous pneumediastinum (Hamman’s syndrome) is a rare pathology defined as the presence of free air in the mediastinum with subcutaneous emphysema without trauma or medical problem. It is also a rare complication of labour and delivery and it usually occurs in the second stage of labour. A twenty-six-year-old primigravida presented to our hospital at 39 weeks and 6 days in spontaneous labour. Two hours following the delivery the patient developed neck tightness and chest tenderness with palpation. Chest X-ray and CT scan revealed pneumomediastinum extending into the soft tissue of the neck. A conservative management was performed. Spontaneous pneumomediastinum is a rare condition with a reported incidence of less than 1:44000 and in the setting of pregnancy or labor 1:100000. Regarding pregnancy, the valsalva maneuvers produced in the second stage of labor has been implicated in the development of spontaneous pneumomediastinum. Chest X-ray (posteroanterior and lateral view) is the most important test to confirm the diagnosis. The Hamman’s syndrome has usually a benign course and the management in often conservative. A timely diagnosis of Hamman’s syndrome is necessary for patient safety and correct management, but most cases have a self-limiting course