87 research outputs found
Optimal photonic indistinguishability tests in multimode networks
Particle indistinguishability is at the heart of quantum statistics that
regulates fundamental phenomena such as the electronic band structure of
solids, Bose-Einstein condensation and superconductivity. Moreover, it is
necessary in practical applications such as linear optical quantum computation
and simulation, in particular for Boson Sampling devices. It is thus crucial to
develop tools to certify genuine multiphoton interference between multiple
sources. Here we show that so-called Sylvester interferometers are near-optimal
for the task of discriminating the behaviors of distinguishable and
indistinguishable photons. We report the first implementations of integrated
Sylvester interferometers with 4 and 8 modes with an efficient, scalable and
reliable 3D-architecture. We perform two-photon interference experiments
capable of identifying indistinguishable photon behaviour with a Bayesian
approach using very small data sets. Furthermore, we employ experimentally this
new device for the assessment of scattershot Boson Sampling. These results open
the way to the application of Sylvester interferometers for the optimal
assessment of multiphoton interference experiments.Comment: 9+10 pages, 6+6 figures, added supplementary material, completed and
updated bibliograph
Multidimensional evaluation of performance: experimental application of the balanced scorecard in Ferrara university hospital
<p>Abstract</p> <p>Background and Aims</p> <p>One of the best-known performance planning and evaluation techniques utilising both monetary and non-monetary data is the <it>Balanced Scorecard (BSC)</it>. This is a means of rationalising the global activity of a business in the attempt to create value, and to translate the company vision into a set of tactical objectives and measurable strategies. The aim of this study was to implement and evaluate the use of BSC in two departments of the St. Anna University Hospital, Ferrara: the Analysis Laboratory and Digestive Endoscopy operating units (OU).</p> <p>Materials and methods</p> <p>With the collaboration of the health workers involved, a precise methodological programme was pursued: Definition of the strategic map from 4 perspectives, according to Kaplan and Norton, Definition of the Key Performance Areas (KPA), or macro-objectives, Identification of the cause-effect relationships between KPAs, Identification of the sub-objectives of each KPA, Definition of the Key Performance Indicators (KPI), Definition of the weight/importance of each objective in the global evaluation.</p> <p>Results</p> <p>The information gathered permitted the definition of macro- and sub-objectives for each perspective, as well as determining the relevant indicators, standards, weights, frequency of detection and means of acquisition. Strategic maps showing the cause/effect relationships in each OU were created, as were 'evaluation panels', which describe the global performance of each department. For each perspective, the fundamental data were summarised in one table. Evaluation of each perspective yielded a positive result for the majority of the objectives, and the global result (including all 4 perspectives) was found to be satisfactory.</p> <p>Discussion-Conclusion</p> <p>The Balanced Scorecard was implemented in the abovementioned OUs of St. Anna University Hospital, Ferrara, after the health workers themselves realised the need for change.</p> <p>In our research the employees were pleased to be evaluated, not only for the financial outcomes, but also for the satisfaction of improving internal procedure, relationships with the community and their own growth/learning. BSC is an ideal point of contact between the financial and clinical dimensions of management. However, difficulties in its application were faced, among these, at least in the initial phase, the lack of information systems able to drive it, and the complexity of the research for specific indicators needed to be overcome. The time factor (on average, at least two years are required) and the availability of technological resources were also limiting factors.</p> <p>The rapid diffusion of BSC among the principal international profit and non-profit organisations is testament to its great potential. This project could be seen as a preparatory phase in the strategical analysis of a subsequent business plan.</p
Experimental generalized quantum suppression law in Sylvester interferometers
Photonic interference is a key quantum resource for optical quantum
computation, and in particular for so-called boson sampling machines. In
interferometers with certain symmetries, genuine multiphoton quantum
interference effectively suppresses certain sets of events, as in the original
Hong-Ou-Mandel effect. Recently, it was shown that some classical and
semi-classical models could be ruled out by identifying such suppressions in
Fourier interferometers. Here we propose a suppression law suitable for
random-input experiments in multimode Sylvester interferometers, and verify it
experimentally using 4- and 8-mode integrated interferometers. The observed
suppression is stronger than what is observed in Fourier interferometers of the
same size, and could be relevant to certification of boson sampling machines
and other experiments relying on bosonic interference.Comment: 5 pages, 3 figures + 11 pages, 3 figures Supplementary Informatio
Photonic simulation of entanglement growth and engineering after a spin chain quench
The time evolution of quantum many-body systems is one of the most important processes for benchmarking quantum simulators. The most curious feature of such dynamics is the growth of quantum entanglement to an amount proportional to the system size (volume law) even when interactions are local. This phenomenon has great ramifications for fundamental aspects, while its optimisation clearly has an impact on technology (e.g., for on-chip quantum networking). Here we use an integrated photonic chip with a circuit-based approach to simulate the dynamics of a spin chain and maximise the entanglement generation. The resulting entanglement is certified by constructing a second chip, which measures the entanglement between multiple distant pairs of simulated spins, as well as the block entanglement entropy. This is the first photonic simulation and optimisation of the extensive growth of entanglement in a spin chain, and opens up the use of photonic circuits for optimising quantum devices
Experimental Scattershot Boson Sampling
Boson Sampling is a computational task strongly believed to be hard for
classical computers, but efficiently solvable by orchestrated bosonic
interference in a specialised quantum computer. Current experimental schemes,
however, are still insufficient for a convincing demonstration of the advantage
of quantum over classical computation. A new variation of this task,
Scattershot Boson Sampling, leads to an exponential increase in speed of the
quantum device, using a larger number of photon sources based on parametric
downconversion. This is achieved by having multiple heralded single photons
being sent, shot by shot, into different random input ports of the
interferometer. Here we report the first Scattershot Boson Sampling
experiments, where six different photon-pair sources are coupled to integrated
photonic circuits. We employ recently proposed statistical tools to analyse our
experimental data, providing strong evidence that our photonic quantum
simulator works as expected. This approach represents an important leap toward
a convincing experimental demonstration of the quantum computational supremacy.Comment: 8 pages, 5 figures (plus Supplementary Materials, 14 pages, 8
figures
Glioblastoma multiforme: a multidisciplinary approach to overcome chemoresistance and find new therapeutic strategies
Objectives: Glioblastoma multiforme is the most frequent malignant brain tumor. Patients die within 15 months after diagnosis. The failure of current therapies is ascribed to a subpopulation of cells with stem-like properties, called glioma stem cells (GSCs). The aim of this study is to develop new effective therapies. Moreover, we want to better characterize the orthotopic xenograft model established by GSCs injection into NOD/SCID mice.
Materials and methods: We tested Temolomide and Valproic acid treatments, alone and in combination, on seven GSC lines by MTT assay and we sequenced p53. Moreover, we characterized our xenograft model investigating the expression of stemness and differentiation markers by immunohistochemistry on FFPE tissues and by immunofluorescence on the correspondent cell line. Finally, we performed aCGH on the DNA extracted from the cell line and from FFPE tissues.
Results: GSCs were resistant to Temozolomide and slightly sensitive to Valproic acid. The two drugs exerted a synergistic effect when combined performing a pre-conditioning with Valproic acid. Furthermore, several cell lines carry p53 mutations. IF and IHC showed a perfect correspondence for stemness markers expression, but discordant data for the others. aCGH analysis evidenced numerous alterations specific for the ex vivo sample, suggesting the presence of an in vivo clonal selection.
Discussion: This work shows the importance of murine microenvironment in GSCs phenotype in vivo and suggests the possibility to use our combined treatment for therapeutic purposes.
Conclusions: Orthotopic models from GSCs and in vitro grown cell lines represent good models for the development of GSC-targeted therapies
Learning an unknown transformation via a genetic approach
Recent developments in integrated photonics technology are opening the way to the fabrication of complex linear optical interferometers. The application of this platform is ubiquitous in quantum information science, from quantum simulation to quantum metrology, including the quest for quantum supremacy via the boson sampling problem. Within these contexts, the capability to learn efficiently the unitary operation of the implemented interferometers becomes a crucial requirement. In this letter we develop a reconstruction algorithm based on a genetic approach, which can be adopted as a tool to characterize an unknown linear optical network. We report an experimental test of the described method by performing the reconstruction of a 7-mode interferometer implemented via the femtosecond laser writing technique. Further applications of genetic approaches can be found in other contexts, such as quantum metrology or learning unknown general Hamiltonian evolutions
Thyrospheres from B-CPAP cell line with BRAF and TERT promoter mutations have different functional and molecular features than parental cells
Human thyroid cancer derived cell lines are widely used to study the mechanisms involved in thyroid carcinogenesis. However, there is limited availability of non-cross-contaminated cancer cell lines derived from papillary thyroid carcinoma (PTC), and the B-CPAP cell line is one of the few such lines. B-CPAP cells have been genetically and cytogenetically well-characterized, but details of their stemness features remain uncertain. Considering that this cell line is extensively used for in vitro studies on thyroid tumorigenesis, we broaden its functional and molecular profiles as well as the tumorigenic capacity. We used functional assays (sphere-forming capacity and efficiency), assessed self-renewal and propagation efficiency and tested in vivo tumorigenicity in Hsd:Athymic Nude-Foxn1nu mice. Expression of markers of stemness, differentiation, and epithelial-mesenchymal transition were estimated at RNA and protein levels in adherent parental cells and sphere-forming cells. Functional aspects and stemness features were compared with normal thyrocytes. Protein expression of xenograft tumors was evaluated by immunohistochemistry. B-CPAP sphere-forming cells were able to form thyrospheres theoretically indefinitely in an appropriate serum-free medium, reverting to the adherent parental cell phenotype when cultured in differentiation medium. Different expression of ALDH1-A1 and CD44 stemness markers and TTF-1 and CK19 differentiation markers allowed discrimination between isolated sphere-forming cells and adherent parental cells, indicating that sphere-forming cells retained stem-like features. In keeping with these observations, tumorigenicity assays confirmed that, relative to parental adherent cells, thyrospheres had enhanced capacity to initiate xenograft tumors. Thyrospheres from normal cell line retained very low functional capacity, as well as different stemness markers expression compared to tumor thyrospheres. Our findings may constitute a useful background to develop an in vitro model for assessing the origin and progression of papillary thyroid carcinoma bearing BRAFV600E and TERT promoter mutations
Allelopathic effect of Baccharis ulicina on germination and initial growth of Avena sativa, Lolium perenne and Raphanus sativus
Baccharis ulicina es una maleza ampliamente
distribuida en los pastizales de la zona semiárida
argentina. A fin de evaluar sus posibles efectos
alelopáticos, se utilizaron extractos acuosos de
B. ulicina (hoja, tallo, raÃz y planta entera) a dos
concentraciones (50 y 150 g tejido/L agua) sobre
la germinación y crecimiento inicial de Avena
sativa, Lolium perenne y Raphanus sativus.
Para cada especie se regaron 100 semillas y se
mantuvieron a 25°C y oscuridad. Se registraron
la germinación de las semillas y la longitud de
coleóptilo / hipocótile (C/H) y radÃcula (R). Con
los datos obtenidos se determinó: porcentaje
de germinación, coeficiente de velocidad de
germinación, vigor de la germinación, inhibición
de la germinación, inhibición de la longitud de
la radÃcula y del coleóptilo / hipocótile e Ãndice
de vigor de radÃcula y de coleóptilo / hipocótile.
Los extractos con alta concentración redujeron
la germinación en promedio 65% mientras que
inhibieron la longitud en 58,8% (C/H) y 93,3% (R)
para A. sativa; 71,5% (C/H) y 87,9% (R) para
L. perenne, y 93,8% (C/H) y 94,5% (R) para
R. sativus. Se registró un evidente efecto fitotóxico
de B. ulicina sobre las especies evaluadas,
indicando que la alelopatÃa serÃa una estrategia
ecológica de la especie.Baccharis ulicina is a weed widely distributed
in pastures of the semiarid zone of Argentina.
With the aim of evaluate potential allelopathic
effects, aqueous extracts of B. ulicina (leaf, stem,
root and whole plant) at two concentrations
(50 and 150 g tissue/L water) were used on
germination and initial growth of Avena sativa,
Lolium perenne and Raphanus sativus. For each
species, 100 seeds were watered and maintained
at 25°C at darkness. Seed germination and length
of coleoptile / hypocotyl (C/H) and radicle (R)
was measured. Then, germination percentage,
germination rate coefficient, germination vigor,
inhibition of germination, inhibition of radicle
length and coleoptile / hypocotyl length, radicle
vigor index and the coleoptile / hypocotyl vigor
index were calculated. High concentration
extracts reduced germination an average of 65%,
in addition, they produced a length inhibition
of 58.8% (C/H) and 93.3% (R) to A. sativa;
71.5% (C/H) and 87.9% (R) to L. perenne, and
93.8% (C/H) and 94.5% (R) to R. sativus. There
was an evident phytotoxic effect of B. ulicina on
evaluated species, indicating that allelopathy
would be an ecological strategy of the species.Fil: Tucat, Guillermo.
Centro de Recursos Naturales Renovables de la Zona Semiárida (Buenos Aires, Argentina).Fil: Bentivegna, Diego.
Centro de Recursos Naturales Renovables de la Zona Semiárida (Buenos Aires, Argentina).Fil: Fernández, Osvaldo.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: Busso, Carlos.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: Brevedan, Roberto.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: Mujica, MarÃa de la Merced.Fil: Torres, Yanina.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: Daddario, Juan.
Centro de Recursos Naturales Renovables de la Zona Semiárida (Buenos Aires, Argentina).Fil: Ithurrart, Leticia.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: Giorgetti, Hugo.
Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental Patagones.Fil: RodrÃguez, Gustavo.
Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental Patagones.Fil: Montenegro, Oscar.
Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental Patagones.Fil: Baioni, Sandra.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: EntÃo, José.Fil: Fioretti, MarÃa Nélida.
Universidad Nacional del Sur. Departamento de AgronomÃ
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