Integrated optical waveplates for arbitrary operations on polarization-encoded single-qubits

Integrated photonic technologies applied to quantum optics have recently enabled a wealth of breakthrough experiments in several quantum information areas. Path encoding was initially used to demonstrate operations on single or multiple qubits. However, a polarization encoding approach is often simpler and more effective. Two-qubits integrated logic gates as well as complex interferometric structures have been successfully demonstrated exploiting polarization encoding in femtosecond-laser-written photonic circuits. Still, integrated devices performing single-qubit rotations are missing. Here we demonstrate waveguide-based waveplates, fabricated by femtosecond laser pulses, capable to effectively produce arbitrary single-qubit operations in the polarization encoding. By exploiting these novel components we fabricate and test a compact device for the quantum state tomography of two polarization-entangled photons. The integrated optical waveplates complete the toolbox required for a full manipulation of polarization-encoded qubits on-chip, disclosing new scenarios for integrated quantum computation, sensing and simulation, and possibly finding application also in standard photonic devices

Energy-efficient Feedback Tracking on Embedded Smart Cameras by Hardware-level Optimization

Embedded systems have limited processing power, memory and energy. When camera sensors are added to an embedded system, the problem of limited resources becomes even more pronounced. In this paper, we introduce two methodologies to increase the energy-efficiency and battery-life of an embedded smart camera by hardware-level operations when performing object detection and tracking. The CITRIC platform is employed as our embedded smart camera. First, down-sampling is performed at hardware level on the micro-controller of the image sensor rather than performing software-level down-sampling at the main microprocessor of the camera board. In addition, instead of performing object detection and tracking on whole image, we first estimate the location of the target in the next frame, form a search region around it, then crop the next frame by using the HREF and VSYNC signals at the micro-controller of the image sensor, and perform detection and tracking only in the cropped search region. Thus, the amount of data that is moved from the image sensor to the main memory at each frame is optimized. Also, we can adaptively change the size of the cropped window during tracking depending on the object size. Reducing the amount of transferred data, better use of the memory resources, and delegating image down-sampling and cropping tasks to the micro-controller on the image sensor, result in significant decrease in energy consumption and increase in battery-life. Experimental results show that hardware-level down-sampling and cropping, and performing detection and tracking in cropped regions provide 41.24% decrease in energy consumption, and 107.2% increase in battery-life. Compared to performing software-level down-sampling and processing whole frames, proposed methodology provides an additional 8 hours of continuous processing on 4 AA batteries, increasing the lifetime of the camera to 15.5 hours

Uptake of nitrate by phytoplankton in two different marine environments in the province of Chubut (42°-46°S, Argentina)

La distribución espacio-temporal de los nutrientes y procesos de producción primaria son fundamentales para la comprensión del funcionamiento de ecosistemas marinos. Al respecto, adquiere gran relevancia ecosistémica la cuantificación de la producción primaria nueva y regenerada. En el presente trabajo se estimó la producción nueva a partir de la medición de la incorporación de nitrato por el fitoplancton, mediante incubación de muestras enriquecidas con isótopos estables del nitrógeno ( 15 NO 3 ) junto con la medición de temperatura, salinidad, pH, clorofila- a y abundancia de los principales grupos fitoplanctónicos. Los experimentos fueron realizados en cabo Dos Bahías (CDB) (46°S) (ambiente de aguas abiertas sin influencia antrópica y profundidades mayores a 50 m) y Bahía Nueva (BN) (42°S) (ambiente de aguas semicerradas con posible influencia antrópica y profundidades menores a 10 m). La temperatura, la salinidad y el pH fueron similares en los 2 ecosistemas analizados. En BN la concentración media de nitrato, fosfato y silicato fue de 0,19 ± 0,12 μM, 0,85 ± 0,09 μM y 1,77 ± 0,23 μM respectivamente. Comparativamente, en CDB la concentración de nitrato y silicato fue mayor (0,86 ± 1,28 μM y 3,69 ± 1,07 μM respectivamente), mientras que la concentración de fosfato presentó valores menores (0,66 ± 0,20 μM). La concentración de clorofila- a no estuvo asociada a la concentración de nutrientes. En CDB, los dinoflagelados y las criptófitas fueron los grupos dominantes y su abundancia correlacionó positivamente con la incorporación de nitrato. En BN dominaron las diatomeas, sin asociarse a esta variable. Se concluye que en aguas superficiales, la producción nueva fue similar en los 2 ambientes y mayor que en el estrato sub-superficial.The spatio-temporal distribution of nutrients and primary production processes are fundamental to understand the functioning of marine ecosystems. In this regard, the quantification of the new and regenerated primary production is highly relevant. In this work, the new production was estimated from the measurement of the uptake of nitrate by the phytoplankton by incubating samples enriched with stable isotopes of nitrogen ( 15 NO 3 ) together with the measurement of temperature, salinity, pH, chlorophyll- a and the measure of the cell abundance of the major phytoplankton groups. The experiments were carried out in cape Dos Bahías (CBD) (46°S) (open water environment without anthropogenic influence and depths greater than 50 m) and Bahía Nueva (BN) (42°S) (semi-enclosed sea environment with possible anthropogenic influence and depths less than 10 m). Temperature, salinity and pH were similar in the 2 analyzed ecosystems. The average concentration of nitrate, phosphate and silicate in BN was 0.19 ± 0.12 μM, 0.85 ± 0.09 μM and 1.77 ± 0.23 μM respectively. Comparatively, nitrate and silicate concentration in CDB was higher (0.86 ± 1.28 μM and 3.69 ± 1.07 μM respectively), while the phosphate concentration showed lower values (0.66 ± 0.20 μM). The concentration of chlorophyll- a was not associated with the nitrate uptake. In CBD, dinoflagellates and cryptophytes were the dominant groups and their abundance was positively correlated with the uptake of nitrate. In BN the diatoms dominated and were not associated with this parameter. We conclude that the new production in surface waters was similar for both environments and higher than in the sub-surface layer.Fil: Paparazzo, Flavio Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Farias, Laura. Univer sidad de Concepción; Chile. Universidad de Chile. Facultad de Cienci as Físicas y Matemáticas; ChileFil: Santinelli, Norma Herminia. Universidad Nacional de la Patagonia; ArgentinaFil: Alder, Viviana Andrea. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Esteves, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentin

The Length and Flexibility of the 2-Substituent of 9-Ethyladenine Derivatives Modulate Affinity and Selectivity for the Human A2A Adenosine Receptor

The A2A adenosine receptor (A2A AR) is a key target for the development of pharmacological tools for the treatment of central nervous system disorders. Previous works have demonstrated that the insertion of substituents at various positions on adenine leads to A2A AR antagonists with affinity in the micromolar to nanomolar range. In this work, a series of 9-ethyladenine derivatives bearing phenylalkylamino, phenylakyloxy or phenylakylthio groups of different lengths at the 2-position were synthesised and tested against the human adenosine receptors. The derivatives showed sub-micromolar affinity for these membrane proteins. The further introduction of a bromine atom at the 8-position has the effect of improving the affinity and selectivity for all ARs and led to compounds that are able bind to the A2A AR subtype at low nanomolar levels. Functional studies confirmed that the new adenine derivatives behave as A2A AR antagonists with half-maximal inhibitory concentration values in the nanomolar range. Molecular modelling studies provide a description of the possible binding mode of these compounds at the A2A AR and an interpretation of the affinity data at this AR subtype

The Natural History of Asymptomatic Ventricular Pre-Excitation A Long-Term Prospective Follow-Up Study of 184 Asymptomatic Children

ObjectivesThe aim of this study was to describe the natural history of asymptomatic ventricular pre-excitation in children and to determine predictors of potentially life-threatening arrhythmic events.BackgroundSudden death can be the first clinical manifestation in asymptomatic children with ventricular pre-excitation, but reduction of its incidence by prophylactic ablation requires the identification of subjects at high risk.MethodsBetween 1995 and 2005 we prospectively collected clinical and electrophysiologic data from 184 children (66% male; median age 10 years; range 8 to 12 years) with asymptomatic ventricular pre-excitation on the electrocardiogram. After electrophysiologic testing, subjects were followed as outpatients taking no medications. The primary end point of the study was the occurrence of arrhythmic events. Predictors of potentially life-threatening arrhythmias were analyzed.ResultsOver a median follow-up of 57 months (min/max 32/90 months) after electrophysiologic testing, 133 children (mean age 10 years; range 8 to 12 years) did not experience arrhythmic events, remaining totally asymptomatic, while 51 children had within 20 months (min/max 8/60 months) a first arrhythmic event, which was potentially life-threatening in 19 of them (mean age 10 years; range 10 to 14 years). Life-threatening tachyarrhythmias resulted in cardiac arrest (3 patients), syncope (3 patients), atypical symptoms (8 patients), or minimal symptoms (5 patients). Univariate analysis identified tachyarrhythmia inducibility (p < 0.001), anterograde refractory period of accessory pathways (APERP) ≤240 ms (p < 0.001), and multiple accessory pathways (p < 0.001) as risk factors for potentially life-threatening arrhythmic events. Independent predictors by multivariate analysis were APERP (p = 0.001) and multiple accessory pathway (p = 0.001).ConclusionsThese findings are potentially relevant in terms of early identification of high-risk asymptomatic children with ventricular pre-excitation. Subjects with short APERPs and multiple pathways are at higher risk of developing life-threatening arrhythmic events and are the best candidates for prophylactic ablation

Cellular immune profiling of lung and blood compartments in patients with SARS-CoV-2 infection

Background: SARS-CoV-2 related immunopathology may be the driving cause underlying severe COVID-19. Through an immunophenotyping analysis on paired bronchoalveolar lavage fluid (BALF) and blood samples collected from mechanically ventilated patients with COVID-19-associated Acute Respiratory Distress Syndrome (CARDS), this study aimed to evaluate the cellular immune responses in survivors and non-survivors of COVID-19. Methods: A total of 36 paired clinical samples of bronchoalveolar lavage fluid (BALF) mononuclear cells (BALF-MC) and peripheral blood mononuclear cells (PBMC) were collected from 18 SARS-CoV-2-infected subjects admitted to the intensive care unit (ICU) of the Policlinico Umberto I, Sapienza University Hospital in Rome (Italy) for severe interstitial pneumonia. The frequencies of monocytes (total, classical, intermediate and non-classical) and Natural Killer (NK) cell subsets (total, CD56bright and CD56dim), as well as CD4+ and CD8+ T cell subsets [naïve, central memory (TCM) and effector memory (TEM)], and those expressing CD38 and/or HLADR were evaluated by multiparametric flow cytometry. Results: Survivors with CARDS exhibited higher frequencies of classical monocytes in blood compared to non-survivors (p &lt; 0.05), while no differences in the frequencies of the other monocytes, NK cell and T cell subsets were recorded between these two groups of patients (p &gt; 0.05). The only exception was for peripheral naïve CD4+ T cells levels that were reduced in non-survivors (p = 0.04). An increase in the levels of CD56bright (p = 0.012) and a decrease in CD56dim (p = 0.002) NK cell frequencies was also observed in BALF-MC samples compared to PBMC in deceased COVID-19 patients. Total CD4+ and CD8+ T cell levels in the lung compartment were lower compared to blood (p = 0.002 and p &lt; 0.01, respectively) among non-survivors. Moreover, CD38 and HLA-DR were differentially expressed by CD4+ and CD8+ T cell subsets in BALF-MC and in PBMC among SARS-CoV-2-infected patients who died from COVID-19 (p &lt; 0.05). Conclusions: These results show that the immune cellular profile in blood and pulmonary compartments was similar in survivors and non-survivors of COVID-19. T lymphocyte levels were reduced, but resulted highly immune-activated in the lung compartment of patients who faced a fatal outcome

Study of radiation damage and substrate resistivity effects from beam test of silicon microstrip detectors using LHC readout electronics

We present the beam test results of single-sided silicon microstrip detectors, with different substrate resistivities. The effects of radiation damage are studied for a detector irradiated to a fluence of 2.4 multiplied by 10**1**4 n/cm**2. The detectors are read out with the APV6 chip, which is compatible with the 40 MHz LHC clock. The performance of different detectors and readout modes are studied in terms of signal-to-noise ratio and efficiency

The G Protein-Coupled Receptor GPR17: Overview and Update

The GPR17 receptor is a G protein-coupled receptor (GPCR) that seems to respond to two unrelated families of endogenous ligands: nucleotide sugars (UDP, UDP-galactose, and UDP-glucose) and cysteinyl leukotrienes (LTD4 , LTC4 , and LTE4 ), with significant affinity at micromolar and nanomolar concentrations, respectively. This receptor has a broad distribution at the level of the central nervous system (CNS) and is found in neurons and in a subset of oligodendrocyte precursor cells (OPCs). Unfortunately, disparate results emerging from different laboratories have resulted in a lack of clarity with regard to the role of GPR17-targeting ligands in OPC differentiation and in myelination. GPR17 is also highly expressed in organs typically undergoing ischemic damage and has various roles in specific phases of adaptations that follow a stroke. Under such conditions, GPR17 plays a crucial role; in fact, its inhibition decreases the progression of ischemic damage. This review summarizes some important features of this receptor that could be a novel therapeutic target for the treatment of demyelinating diseases and for repairing traumatic injury

Genotype/Phenotype Relationship in a Consanguineal Family With Brugada Syndrome Harboring the R1632C Missense Variant in the SCN5A Gene

Brugada syndrome (BrS) is a known cause of sudden cardiac death. The genetic basis of BrS is not well understood, and no one single gene is linked to even a majority of BrS cases. However, mutations in the gene SCN5A are the most common, although the high amount of phenotypic variability prevents a clear correlation between genotype and phenotype. Research techniques are limited, as most BrS cases still remain without a genetic diagnosis, thus impairing the implementation of experimental models representative of a general pathogenetic mechanism. In the present study, we report the largest family to-date with the segregation of the heterozygous variant NM_198056:c.4894C&gt;T (p.Arg1632Cys) in the SCN5A gene. The genotype-phenotype relationship observed suggests a likely pathogenic effect of this variant. Functional studies to better understand the molecular effects of this variant are warranted