566 research outputs found

    First Calorimetric Measurement of OI-line in the Electron Capture Spectrum of 163^{163}Ho

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    The isotope 163^{163}Ho undergoes an electron capture process with a recommended value for the energy available to the decay, QECQ_{\rm EC}, of about 2.5 keV. According to the present knowledge, this is the lowest QECQ_{\rm EC} value for electron capture processes. Because of that, 163^{163}Ho is the best candidate to perform experiments to investigate the value of the electron neutrino mass based on the analysis of the calorimetrically measured spectrum. We present for the first time the calorimetric measurement of the atomic de-excitation of the 163^{163}Dy daughter atom upon the capture of an electron from the 5s shell in 163^{163}Ho, OI-line. The measured peak energy is 48 eV. This measurement was performed using low temperature metallic magnetic calorimeters with the 163^{163}Ho ion implanted in the absorber. We demonstrate that the calorimetric spectrum of 163^{163}Ho can be measured with high precision and that the parameters describing the spectrum can be learned from the analysis of the data. Finally, we discuss the implications of this result for the Electron Capture 163^{163}Ho experiment, ECHo, aiming to reach sub-eV sensitivity on the electron neutrino mass by a high precision and high statistics calorimetric measurement of the 163^{163}Ho spectrum.Comment: 5 pages, 3 figure

    Overall Survival Benefit with Tebentafusp in Metastatic Uveal Melanoma

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    Background: Uveal melanoma is a disease that is distinct from cutaneous melanoma, with a low tumor mutational burden and a 1-year overall survival of approximately 50% in patients with metastatic uveal melanoma. Data showing a proven overall survival benefit with a systemic treatment are lacking. Tebentafusp is a bispecific protein consisting of an affinity-enhanced T-cell receptor fused to an anti-CD3 effector that can redirect T cells to target glycoprotein 100-positive cells. Methods: In this open-label, phase 3 trial, we randomly assigned previously untreated HLA-A*02:01-positive patients with metastatic uveal melanoma in a 2:1 ratio to receive tebentafusp (tebentafusp group) or the investigator's choice of therapy with single-agent pembrolizumab, ipilimumab, or dacarbazine (control group), stratified according to the lactate dehydrogenase level. The primary end point was overall survival. Results: A total of 378 patients were randomly assigned to either the tebentafusp group (252 patients) or the control group (126 patients). Overall survival at 1 year was 73% in the tebentafusp group and 59% in the control group (hazard ratio for death, 0.51; 95% confidence interval [CI], 0.37 to 0.71; P<0.001) in the intention-to-treat population. Progression-free survival was also significantly higher in the tebentafusp group than in the control group (31% vs. 19% at 6 months; hazard ratio for disease progression or death, 0.73; 95% CI, 0.58 to 0.94; P = 0.01). The most common treatment-related adverse events in the tebentafusp group were cytokine-mediated events (due to T-cell activation) and skin-related events (due to glycoprotein 100-positive melanocytes), including rash (83%), pyrexia (76%), and pruritus (69%). These adverse events decreased in incidence and severity after the first three or four doses and infrequently led to discontinuation of the trial treatment (2%). No treatment-related deaths were reported. Conclusions: Treatment with tebentafusp resulted in longer overall survival than the control therapy among previously untreated patients with metastatic uveal melanoma. (Funded by Immunocore; ClinicalTrials.gov number, NCT03070392; EudraCT number, 2015-003153-18.)

    Firm heterogeneity and wages under different bargaining regimes : does a centralised union care for low-productivity firms?

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    This paper studies the relationship between wages and the degree of firm heterogeneity in a given industry under different wage setting structures. To derive testable hypotheses, we set up a theoretical model that analyses the sensitivity of wages to the variability in productivity conditions in a unionsised oligopoly framework. The model distinguishes centralised and decentralised wage determination. The theoretical results predict wages to be negatively associated with the degree of firm heterogeneity under centralised wage-setting, as unions internalise negative externalities of a wage increase for low-productivity firms. We test this prediction using a linked employeremployee panel data set from the German mining and manufacturing sector. Consistent with our hypotheses, the empirical results suggest that under industry-level bargaining workers in more heterogeneous sectors receive lower wages than workers in more homogeneous sectors. In contrast, the degree of firm heterogeneity is found to have no negative impact on wages in uncovered firms and under firm-level contracts

    Spatial organization in cyclic Lotka-Volterra systems

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    We study the evolution of a system of NN interacting species which mimics the dynamics of a cyclic food chain. On a one-dimensional lattice with N<5 species, spatial inhomogeneities develop spontaneously in initially homogeneous systems. The arising spatial patterns form a mosaic of single-species domains with algebraically growing size, (t)tα\ell(t)\sim t^\alpha, where α=3/4\alpha=3/4 (1/2) and 1/3 for N=3 with sequential (parallel) dynamics and N=4, respectively. The domain distribution also exhibits a self-similar spatial structure which is characterized by an additional length scale, L(t)tβ{\cal L}(t)\sim t^\beta, with β=1\beta=1 and 2/3 for N=3 and 4, respectively. For N5N\geq 5, the system quickly reaches a frozen state with non interacting neighboring species. We investigate the time distribution of the number of mutations of a site using scaling arguments as well as an exact solution for N=3. Some possible extensions of the system are analyzed.Comment: 18 pages, 10 figures, revtex, also available from http://arnold.uchicago.edu/~ebn

    Upper limits to interstellar NH^+ and para-NH_2^− abundances. Herschel-HIFI observations towards Sgr B2 (M) and G10.6−0.4 (W31C)

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    The understanding of interstellar nitrogen chemistry has improved significantly with recent results from the Herschel Space Observatory. To set even better constraints, we report here on deep searches for the NH^+ ground state rotational transition J = 1.5−0.5 of the ^2Π_(1/2) lower spin ladder, with fine-structure transitions at 1013 and 1019 GHz, and the para-NH_2^− 1_(1,1)−0_(0,0) rotational transition at 934 GHz towards Sgr B2 (M) and G10.6−0.4 (W31C) using the Herschel Heterodyne Instrument for the Far-Infrared (HIFI). No clear detections of NH^+ are made and the derived upper limits relative to the total number of hydrogen nuclei are ≲2 × 10^(-12) and ≲7 × 10^(-13) in the Sgr B2 (M) molecular envelope and in the G10.6−0.4 molecular cloud, respectively. The searches are, however, complicated by the fact that the 1 013 GHz transition lies only −2.5 km s^(-1) from a CH_2NH line, which is seen in absorption in Sgr B2 (M), and that the hyperfine structure components in the 1019 GHz transition are spread over 134 km s^(-1). Searches for the so far undetected NH_2^− anion turned out to be unfruitful towards G10.6−0.4, while the para-NH_2^− 1_(1,1)−0_(0,0) transition was tentatively detected towards Sgr B2 (M) at a velocity of 19 km s^(-1). Assuming that the absorption occurs at the nominal source velocity of +64 km s^(-1), the rest frequency would be 933.996 GHz, offset by 141 MHz from our estimated value. Using this feature as an upper limit, we found N(p-NH_2^−) ≲4 × 10^(11) cm^(-2), which implies an abundance of ≲8 × 10^(-13) in the Sgr B2 (M) molecular envelope. The upper limits for both species in the diffuse line-of-sight gas are less than 0.1 to 2% of the values found for NH, NH_2, and NH_3 towards both sources, and the abundance limits are ≲2−4 × 10^(-11). An updated pseudo time-dependent chemical model with constant physical conditions, including both gas-phase and surface chemistry, predicts an NH^+ abundance a few times lower than our present upper limits in diffuse gas and under typical Sgr B2 (M) envelope conditions. The NH_2^− abundance is predicted to be several orders of magnitudes lower than our observed limits, hence not supporting our tentative detection. Thus, while NH_2^− may be very difficult to detect in interstellar space, it could, on the other hand, be possible to detect NH^+ in regions where the ionisation rates of H_2 and N are greatly enhanced

    Nitrogen hydrides in interstellar gas II. Analysis of Herschel/HIFI observations towards W49N and G10.6-0.4 (W31C)

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    We have used the Herschel-HIFI instrument to observe interstellar nitrogen hydrides along the sight-lines towards W49N and G10.6-0.4 in order to elucidate the production pathways leading to nitrogen-bearing species in diffuse gas. All detections show absorption by foreground material over a wide range of velocities, as well as absorption associated directly with the hot-core source itself. As in the previously published observations towards G10.6-0.4, the NH, NH2 and NH3 spectra towards W49N show strikingly similar and non-saturated absorption features. We decompose the absorption of the foreground material towards W49N into different velocity components in order to investigate whether the relative abundances vary among the velocity components, and, in addition, we re-analyse the absorption lines towards G10.6-0.4 in the same manner. Abundances, with respect to molecular hydrogen, in each velocity component are estimated using CH. The analysis points to a co-existence of the nitrogen hydrides in diffuse or translucent interstellar gas with a high molecular fraction. Towards both sources, we find that NH is always at least as abundant as both o-NH2 and o-NH3, in sharp contrast to previous results for dark clouds. We find relatively constant N(NH)/N(o-NH3) and N(o-NH2)/N(o-NH3) ratios with mean values of 3.2 and 1.9 towards W49N, and 5.4 and 2.2 towards G10.6-0.4, respectively. The mean abundance of o-NH3 is ~2x10^-9 towards both sources. The nitrogen hydrides also show linear correlations with CN and HNC towards both sources, and looser correlations with CH. The upper limits on the NH+ abundance indicate column densities < 2 - 14 % of N(NH). Surprisingly low values of the ammonia ortho-to-para ratio are found in both sources, ~0.5 - 0.7 +- 0.1. This result cannot be explained by current models as we had expected to find a value of unity or higher.Comment: 35 pages, 74 figure

    Latin America and the Caribbean code against cancer: Developing evidence-based recommendations to reduce the risk of cancer in Latin America and the Caribbean

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    Latin America and the Caribbean (LAC) has a population of more than 650 million inhabitants (8.5% of the world population),1 with a cancer incidence of more than 1.4 million new patients and more than 670,000 deaths in 2018. These figures will increase by 78% by 2040 to more than 2.5 million people diagnosed with cancer each year, and these patients will require medical attention, care, and support. However, many of these new cancer diagnoses can be prevented through public policies, supportive environments, and lifestyles that promote health and prevent cancer (Fig 1).2 In the LAC region, there are many organizations and institutions providing information on cancer prevention, including national cancer institutes, cancer societies and foundations, and public health agencies. Nevertheless, the information is frequently confusing, overwhelming, or even contradictory. The scientific source and credibility, as well as the primary message, differ according to the type of organization that provides the information (eg, patient organization, scientific or governmental institution).For the LAC region, a coalition of institutions and international organizations has joined forces to adapt the European Code to the cancer risks and situation in the LAC region. This involves collecting, analyzing, and evaluating the scientific evidence to support suitable cancer prevention recommendations to the LAC context. A multistakeholder participation in the project is a key approach to ensure that all players will be owners of the Code and true promoters. The coalition is composed of the Pan-American Health Organization (PAHO; also part of the WHO) and the IARC as leading international organizations; a Scientific Committee of senior researchers and distinguished leaders in cancer prevention from LAC; and an Advocacy Group representing important organizations in LAC, including the Latin American and Caribbean Society of Medical Oncology, the Network of Latin-American Cancer Institutes, the Healthy Caribbean Coalition, and the Association of Latin American Leagues Against Cancer.Fil: Cazap, Eduardo. Sociedad Latinoamericana y del Caribe de Oncología Médica; ArgentinaFil: de Almeida, Liz Maria. Instituto Nacional de Câncer Brasil Jose Alencar Gomes da Silva; BrasilFil: Arrossi, Silvina. Centro de Estudios de Estado y Sociedad; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: García, Patricia J.. Universidad Cayetano Heredia; PerúFil: Garmendia, María Luisa. Universidad de Chile; ChileFil: Gil, Enrique. South America Pan-American Health Organization; PerúFil: Hassel, Trevor. Healthy Caribbean Coalition; BarbadosFil: Mayorga, Rubén. South America Pan-American Health Organization; PerúFil: Mohar, Alejandro. Universidad Nacional Autónoma de México; MéxicoFil: Murillo, Raúl. Centro Javeriano de Oncología; ColombiaFil: Owen, Gabriel O.. Healthy Caribbean Coalition; BarbadosFil: Paonessa, Diego. Liga Argentina de Lucha contra el Cancer; ArgentinaFil: Santamaría, Julio. Centro Hemato Oncológico Panamá; PanamáFil: Tortolero Luna, Guillermo. Universidad de Puerto Rico; Puerto RicoFil: Zoss, Walter. Red de Institutos e Instituciones Nacionales de Cancer; BrasilFil: Herrero, Rolando. Agencia Internacional para la Investigación del Cáncer; FranciaFil: Luciani, Silvana. Pan-American Health Organization; Estados UnidosFil: Schüz, Joachim. Agencia Internacional para la Investigación del Cáncer; FranciaFil: Espina, Carolina. Agencia Internacional para la Investigación del Cáncer; Franci

    Multisite Comparison of MRI Defacing Software Across Multiple Cohorts

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    With improvements to both scan quality and facial recognition software, there is an increased risk of participants being identified by a 3D render of their structural neuroimaging scans, even when all other personal information has been removed. To prevent this, facial features should be removed before data are shared or openly released, but while there are several publicly available software algorithms to do this, there has been no comprehensive review of their accuracy within the general population. To address this, we tested multiple algorithms on 300 scans from three neuroscience research projects, funded in part by the Ontario Brain Institute, to cover a wide range of ages (3–85 years) and multiple patient cohorts. While skull stripping is more thorough at removing identifiable features, we focused mainly on defacing software, as skull stripping also removes potentially useful information, which may be required for future analyses. We tested six publicly available algorithms (afni_refacer, deepdefacer, mri_deface, mridefacer, pydeface, quickshear), with one skull stripper (FreeSurfer) included for comparison. Accuracy was measured through a pass/fail system with two criteria; one, that all facial features had been removed and two, that no brain tissue was removed in the process. A subset of defaced scans were also run through several preprocessing pipelines to ensure that none of the algorithms would alter the resulting outputs. We found that the success rates varied strongly between defacers, with afni_refacer (89%) and pydeface (83%) having the highest rates, overall. In both cases, the primary source of failure came from a single dataset that the defacer appeared to struggle with - the youngest cohort (3–20 years) for afni_refacer and the oldest (44–85 years) for pydeface, demonstrating that defacer performance not only depends on the data provided, but that this effect varies between algorithms. While there were some very minor differences between the preprocessing results for defaced and original scans, none of these were significant and were within the range of variation between using different NIfTI converters, or using raw DICOM files
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