Experimental investigation of the dynamics of entanglement: Sudden death, complementarity, and continuous monitoring of the environment

We report on an experimental investigation of the dynamics of entanglement between a single qubit and its environment, as well as for pairs of qubits interacting independently with individual environments, using photons obtained from parametric down-conversion. The qubits are encoded in the polarizations of single photons, while the interaction with the environment is implemented by coupling the polarization of each photon with its momentum. A convenient Sagnac interferometer allows for the implementation of several decoherence channels and for the continuous monitoring of the environment. For an initially-entangled photon pair, one observes the vanishing of entanglement before coherence disappears. For a single qubit interacting with an environment, the dynamics of complementarity relations connecting single-qubit properties and its entanglement with the environment is experimentally determined. The evolution of a single qubit under continuous monitoring of the environment is investigated, demonstrating that a qubit may decay even when the environment is found in the unexcited state. This implies that entanglement can be increased by local continuous monitoring, which is equivalent to entanglement distillation. We also present a detailed analysis of the transfer of entanglement from the two-qubit system to the two corresponding environments, between which entanglement may suddenly appear, and show instances for which no entanglement is created between dephasing environments, nor between each of them and the corresponding qubit: the initial two-qubit entanglement gets transformed into legitimate multiqubit entanglement of the Greenberger-Horne-Zeilinger (GHZ) type.Comment: 15 pages, 14 figures; only .ps was working, now .pdf is also availabl

Supercurrent transport through 1ee-periodic full-shell Coulomb islands

We experimentally investigate supercurrent through Coulomb islands, where island and leads are fabricated from semiconducting nanowires with fully surrounding superconducting shells. Applying flux along the wire yields a series of destructive Little-Parks lobes with reentrant supercurrent. We find Coulomb blockade with 2$e$ peak spacing in the zeroth lobe and 1$e$ average spacing, with regions of significant even-odd modulation, in the first lobe. Evolution of Coulomb-peak amplitude through the first lobe is consistent with a theoretical model of supercurrent carried predominantly by zero-energy states in the leads and the island.Comment: 11 pages, 5+5 figure

Vitrines tecnológicas: o design de websites sobre tecnologia de instituições públicas de ensino e pesquisa brasileiras.

Atores importantes para o desenvolvimento tecnológico nacional, universidades e instituições públicas de pesquisa (ICTs) têm como um de seus objetivos transferir tecnologias para empresas que viabilizem, em escala de mercado, produtos, processos e serviços, gerando inovação. Neste contexto, o presente estudo tem como objetivo caracterizar, do ponto de vista do Design de Interação, vitrines tecnológicas na web de ICTs públicas brasileiras. Para tanto, foi selecionada uma amostra de 20 instituições, divididas em universidades e centros de pesquisa, e mapeados os websites que disponibilizam informações sobre patentes e tecnologias disponíveis para negócio. Os resultados confirmam a ocorrência do uso de vitrines tecnológicas na web como produtos alternativos ou complementares às tradicionais bases de patentes em 75% das instituições pesquisadas. Em seguida, os rótulos empregados para a sua designação foram identificados, os patterns de Design mais recorrentes foram levantados, foram verificadas as principais soluções adotadas para apresentar as tecnologias e checado o seu nível de independência com relação ao website da instituição

Uso de funções discriminantes para comparação de cultivares dos gêneros Cynodon e Digitaria quanto à produção de matéria seca e teores de macronutrientes.

Foi realizado um experirnento no Centro Nacional de Pesquisa de Agrobiologia, Seropédica-RJ, com objetivo de comparar as gramineas Coast cross e Tifton 85, do gênero Cynodon, e as gramíneas Suazi (Digitaria swazilandensis) e Transvala (D. decumbens), do gênero Digitaria, quanto a produção de matéria seca (MS) e teores de macronutrientes da parte aérea e sistema radicular, em 15 amostras de cada cultivar, coletadas no período das chuvas (primavera/verão). A análise discriminante demonstrou que as variáveis Mg, Ca e MS na parte aérea e P e N na raiz foram importantes no processo de discriminação dos cultivares estudados. O cultivar Suázi foi diferente dos dernais avaliados quanto a produção de MS e aos teores de Mg e Ca na parte aérea, além do P e N na raiz. Os cultivares Tifton 85 e Coast cross, apesar de serem do mesmo gênero, diferem quanto a produção de MS e aos teores de Mg e Ca na parte aérea, alem do P e N na raiz. Algumas amostras dos cultivares Tifton 85 e Coast cross apresentaram semelhança com O capim Transvala, com relação a produção de MS e aos teores de Mg e Ca na parte aérea, alem de P e N na raiz. An experiment was carried out at the National Center of Research of Agrobiology, Seropedica--RJ, with objective of evaluating the grasses Coast cross (Cynodon spp.) and Tifton 85 (Cynodon dactylon (L.)), of the Cynodon genus, and the grasses Suazi (Digitaria swazilandensis) and Transvala (Digitaria decumbens), of the Digitaria genus, through the discriminant analysis. The evaluated variables were: dry matter production (DMP) and contents of nitrogen (N), phosphorus (P), magnesium (Mg) and calcium (Ca) in the shoot and root on 15 samples of each grasses, accomplished in the period of the rains (spring/ summer). The discriminant analysis demonstrated that the variables Mg, Ca and dry matter production (DMP) in shoot, and P and N root are important in the discrimination process of the Coast cross, Tifton 85, Suazi and Transvala cultivars. Suazi cultivar is clearly different from the others cultivars, in relationship to Mg and Ca contents and DMP at the shoot, P and N at the root. O Tifton 85 and Coast cross cultivars, in spite of being of the same genus, differ in relationship to Mg and Ca contents and DMP at the shoot, match and N at the root. Some samples of the Tifton 85 and Coast cross cultivars can be similar to the grass Transvala, in relation to the Mg, Ca and DMP contents in shoot, P and N root.Parceria: UFV; PESAGRO-Rio/ESS; UFRRJ; ESALQ

A Mach-Zehnder Interferometer for a Two-Photon Wave Packet

We propose an experiment that permits observation of the de Broglie two-photon wave packet behavior for a pair of photons, using a Mach-Zehnder interferometer. It is based on the use of pulsed lasers to generate pairs of photons via spontaneous parametric down-conversion and the post-selection of events. It differs from previous realizations by the use of a third time-correlated photon to engineer the state of the photons. The same technique can give us which-path information via an ``interaction-free'' experiment and can be used in other experiments on the foundations of quantum mechanics related to wave-particle duality and to nonlocality.Comment: Submmited for publication in Physical Review

Beta Cell Function as a Baseline Predictor of Weight Loss After Bariatric Surgery

Background: Obesity is a multifactorial disease, which is strongly associated to other metabolic disorders. Bariatric surgery is the most effective treatment of morbid obesity. The role of beta cell function in weight loss after bariatric surgery is uncertain. Aim: To evaluate the association between beta cell function and percentage of total body weight loss (TBWL%) 1, 2, 3, and 4 years after bariatric surgery in patients with morbid obesity. Methods: Retrospective longitudinal study in patients with morbid obesity followed in our center between January 2010 and July 2018. Patients were excluded if they had diabetes at baseline or missing data on the needed parameters. We evaluated baseline Homeostatic Model Assessment of IR, Homeostatic Model Assessment of ß-cell function (HOMA-beta), Quantitative Insulin Sensitivity Check Index, and Matsuda and DeFronzo index, and TBWL% at years 1 to 4. Linear regression models were used to evaluate the association of indexes of insulin resistance with TBWL% (unadjusted and adjusted for age, sex, BMI, and type of surgery). Results: There were 1,561 patients included in this analysis. HOMA-beta was negatively associated with TBWL% at second, third, and fourth years post-surgery (ß = -1.04 [-1.82 to -0.26], p<0.01; ß = -1.16 [-2.13 to -0.19], p=0.02; ß = -1.29 [-2.64 to 0.06], p=0.061, respectively). This was not observed in the first year post-surgery nor for the other indexes. Glycemia at baseline was positively associated to EWL% at second and third years post-surgery. Conclusion: ß-cell function at baseline seems to be associated to long-term weight loss, explicitly after the first year post bariatric surgery. This might be a helpful predictor of weight loss in clinical practice.The authors would like to thank all the CRIO group members for following these patients: John Rodrigues Preto; Eduardo Jorge Lima da Costa; Hugo Miguel Santos Sousa; André Manuel Costa Pinho; Carla Cristina Oliveira Rodrigues Teixeira Galego; Maria Flora Ferreira Sampaio Carvalho Correia; Cidália Fátima Castro Carção Gil; Diva Bizarro Figueiredo Melim; Eduardo Gil Ferreira Rodrigues Pinto; Marco António Costa Silva; Cristina Sarmento Pontes Martins; Luis Miguel Gonçalves Pereira; Inês Vasconcelos Sousa Magalhães; Isabel Maria Boavista Vieira Marques Brandão; Sertório Manuel Freitas Andrade, and Patrícia Maria Lopes Nunes. The authors would also like to thank the patients and the hospital for their support. The authors would like to thank to Associação dos Amigos do Serviço de Endocrinologia do Hospital de S. João

Impact Of Sentinel Lymph Node Biopsy In Breast Cancer Patients Treated With Neoadjuvant Chemotherapy

EPS 196 Aim/Introduction: To analyze how many of the patients undergoing neoadjuvant chemotherapy (NCT) may benefit from SLNB, as well as the impact on patient management, especially in those with early axillary involvement. Materials and Methods: We included patients with breast carcinoma candidates to NCT discussed at the Tumor Committee of our hospital (April/2017-August/2019). All of them were subjected to clinical assessment, ultrasound and, if appropriate, histological analysis, axillary pre and post- NCT. Sentinel lymph node detection was performed after periareolar injection of [99mTc]Tc-nanocoloid (74 MBq) the day before surgery. In some cases, blue dye was injected and/or a pre-NPC metal clip was placed in the affected node. Results: Sixty-two patients were included. NCT achieved a complete breast response in 12 patients, partial in 46 and non-response in 4. Initially, 31 patients were classified as N0 and 31 as N+ (28 N1 and 3 N2), achieving a complete axillary response in 58% of N+ (18). SLNB was performed in 49 patients (79%; 100% in N0 and 58% in N+ from baseline). The gamma detection rate of the sentinel lymph node was 91.8% (93.5% in N0 and 88.9% in N+). 28 lymphadenectomies were undergone (45.2%; 22.5% in N0 and 67.7% in N+), 11 due to positive SLNB (5 N0 and 6 N1), 13 owing to lack of axillary response and 4 caused by the non-localization of the sentinel lymph node. SLNB was performed in 58% of N+ patients, of which 44.4% were negative, avoiding lymphadenectomy. Metal clip and/or blue dye techniques were used in 31 cases (50%). Conclusion: SLNB is viable in a high percentage of patients with previous NCT, with a high detection rate, even in patients with early affected axilla, avoiding lymphadenectomy to patients who achieve a complete response of the axillary lymph node

Lack of energy is associated with malnutrition in nursing home residents: Results from the INCUR study

Background: Lack of energy is a symptom frequently complained by older people, leading to the inability to continue functioning at the expected level of activity. This study aimed to investigate whether nutritional status was associated with lack of energy in nursing home (NH) residents. Methods: This was a cross-sectional study. A total of 570 NH residents (72.1% women) in 13 French NHs from the Incidence of pNeumonia and related ConseqUences in nursing home Residents study cohort were included in the study. Lack of energy was measured by the question “Did you feel full of energy during the past week?” from the geriatric depression scale. Nutritional status was evaluated according to Mini Nutritional Assessment Short-Form (MNA-SF). Unadjusted and adjusted logistic regression models were performed to test the association of nutritional status with lack of energy. Results: The mean age of participants was 86.5 (SD 7.5) years. A total of 246 NH residents (43.2%) reported a lack of energy. Overall, 71 (12.5%) residents were malnourished and 323 (56.7%) residents were at risk of malnutrition. Malnutrition was significantly associated with lack of energy (OR&nbsp;=&nbsp;3.42, 95% CI&nbsp;=&nbsp;1.92–6.08, P &lt; 0.001), even after adjustment for potential confounders (OR&nbsp;=&nbsp;2.41, 95% CI&nbsp;=&nbsp;1.29–4.52, P&nbsp;=&nbsp;0.006). Among the single items of the MNA-SF, decrease in food intake, low mobility, and psychological stress or acute disease were individually associated with lack of energy, independently of potential confounders (OR&nbsp;=&nbsp;1.85, 95% CI&nbsp;=&nbsp;1.24–2.77, P&nbsp;=&nbsp;0.003; OR&nbsp;=&nbsp;1.43, 95% CI&nbsp;=&nbsp;1.10–1.86, P&nbsp;=&nbsp;0.008; OR&nbsp;=&nbsp;1.48, 95% CI&nbsp;=&nbsp;1.19–1.84, P &lt; 0.001; for each point respectively). Conclusions: Lack of energy and malnutrition were closely associated. The reporting of lack of energy should lead to a comprehensive assessment of the aging individual (as happening for malnutrition) in order to preventively/promptly act on potentially reversible causes