66 research outputs found
A15 superconductors: An alternative to niobium for RF cavities
Since the international committee for future accelerators recommended that the linear collider design should be based on the superconducting technology, the scientific world interest is now focused on further developments of new resonant cavities fabrication technics and cost reduction. Besides the attempt to improve the Nb sputtered on Cu accelerating structures performances, it is important to pursue research on new materials. The goal will be the achievement of superconducting cavities working better than the Nb ones at 4.2 K. Among the possible candidates, A15 compounds appear to be the most promising. Three of them were chosen: MoâRe system which shows the A15 phase far from the stoichiometric composition (Mo3Re), V3Si that has a really high RRR value, Nb3Sn that is the only A15 compound already used for a resonant accelerating structure [G. Muller, P. Kneisel, D. Mansen, H. Piel, J. Pouryamout, R.W. Roeth, in: Proceedings of the 5th EPAC, London, 1985, p. 2085] and we obtained some interesting preliminary results. We are setting up a 6 GHz cavities measurement system: it is very simple, fast to use and it will give us the opportunity to make such small resonators become our samples
Predictors of progression free survival, overall survival and early cessation of chemotherapy in women with potentially platinum sensitive (PPS) recurrent ovarian cancer (ROC) starting third or subsequent line(> 3) chemotherapy â the GCIG Symptom Benefit Study (SBS)
Background:
Potentially platinum sensitive recurrent ovarian cancer (PPS ROC) is defined by a platinum-free interval of >6 months, and usually treated with platinum-based chemotherapy with variable response and benefit in women who have had 3 or more lines of chemotherapy(â„3). We identified baseline characteristics (health-related quality of life[HRQL] and clinicopathological factors), associated with PFS, OS and early progression (within 8 weeks). The goal is to improve patient selection for chemotherapy based on a nomogram predicting PFS.
Methods:
HRQL was assessed with EORTC QLQ-C30/QLQ-OV28. Associations with PFS and OS were assessed with Cox proportional hazards regression. Variables significant in univariable analysis were included in multivariable analyses using backward elimination to select those significant. Associations with stopping chemotherapy early were assessed with logistic regression.
Results:
378 women were enrolled, with median(m)OS and PFS of 16.6 months and 5.3 months, respectively. The majority had ECOGPS 0â1. Chemotherapy was stopped early in 45/378 participants (12%); with mOS 3.4 months (95% CI: 1.7â7.2). Physical function(PF), role function(RF), cognitive function(CF), social function(SF), Global Health Status(GHS) and abdominal/GI symptoms(AGIS) were significant univariable predictors of PFS(p < 0.030). SF remained significant after adjusting for clinicopathological factors; p = 0.03. PF, RF, CF, SF, GHS and AGIS were significant univariable predictors of OS (p < 0.007); PF, RF, SF and GHS remained significant predictors of OS in multivariable models; p < 0.007. Poor baseline PF and GHS were significant univariable predictors of stopping chemotherapy early (p < 0.007) but neither remained significant after adjusting for clinicopathological factors.
Conclusion:
Baseline HRQL is simple to measure, is predictive of PFS and OS and when used in conjunction with clinicopathological prognostic factors, can assist with clinical decision making and treatment recommendations for women with PPSROCâ„3
Structural Change and the Fall of Income Inequality in Latin America : Agricultural Development, Inter-sectoral Duality, and the Kuznets Curve
In this study we approach the recent decline in income inequality in Latin America from the perspective of structural change with a focus on the relative performance of the agricultural sector. Our focus is on the underlying forces implied by Kuznets (1965). We zoom in on the relative performance of agriculture in the development process and the rural-urban duality and pay particular attention to the last couple of decades in relation to the entire post-1950 period. We attempt to estimate empirically possible theoretical relations with regard to these patterns by posing the following basic questions: how does the resurgence of agriculture relate to the reduction of income inequality and to what extent is this an expression of Latin America moving downward on the Kuznets curve? The literature on agricultureâs relation to the recent changes of income distribution in Latin America is quite limited. For instance, in a recent ECLAC report titled âStructural change for equalityâ (2012), the role of agriculture is not even mentioned. By agriculture we mean both farming and agro-business that processes and transports that output. To our knowledge, this paper is the first attempt to investigate this relationship for the recent decades in the perspective of structural change in Latin America. There are strong theoretical reasons to connect agricultural development to income distribution. The closing of the rural-urban income gap reflects what Reynolds (1975) called a âdynamicâ transformation of agriculture and relates to the contribution agriculture provides for overall growth of the economy. In addition, the elasticity of poverty reduction with respect to growth is estimated to be stronger when growth emanates in the agricultural sector (Ravallion and Chen 2007, de Janvry and Sadoulet 2009). Productivity growth in the lagging sector should also contribute to sectoral labor productivity to convergence and thus helps to reduce inequality (Timmer 1988). For these reasons, the resurgence of agriculture driven partly by improving commodity prices should be given due attention when assessing the decline in income inequality in Latin America. According to the logic of the Kuznets curve, the hypothesized âturning pointâ of the inverted U-curve is generated by a reduction of income inequality in one or both of the sectors and/or a reduction of the rural-urban income gap as the weight of the agricultural sector diminishes, and the income per capita gap between them declines. We find that the recent decline in income inequality is related to the recent resurgence of Latin American agriculture, and, by inference, its lack of decline across most of the 20th century must be related to a lack of productivity change in agriculture. We provide estimates showing that during the recent decades inter-sectoral duality has been reduced by agricultural productivity growth. The duality expressed as an inter-sectoral Gini shows the shape of an inverted U-curve and as such the closing of the rural-urban income gap corroborates with the theoretical expectations postulated by Kuznets. The wider implication of the study is, however, that with slower growth in agricultural labor productivity, continuing improvement in the income distribution becomes more difficult. In the absence of strong manufacturing growth, agriculture might be able to reduce income inequality further if agro-industries remain unskilled labor intensive, thus raising the opportunity cost of unskilled workers. On the other hand, the traditional service sector has perhaps become the ânew agricultural sectorâ in terms of productivity and labor surplus. In other words, the source of the remaining dualism does not come only from rural areas, but also from urban areas
Integrative Genomics Identifies the Molecular Basis of Resistance to Azacitidine Therapy in Myelodysplastic Syndromes
© 2017 The Author(s) Myelodysplastic syndromes and chronic myelomonocytic leukemia are blood disorders characterized by ineffective hematopoiesis and progressive marrow failure that can transform into acute leukemia. The DNA methyltransferase inhibitor 5-azacytidine (AZA) is the most effective pharmacological option, but only âŒ50% of patients respond. A response only manifests after many months of treatment and is transient. The reasons underlying AZA resistance are unknown, and few alternatives exist for non-responders. Here, we show that AZA responders have more hematopoietic progenitor cells (HPCs) in the cell cycle. Non-responder HPC quiescence is mediated by integrin α5 (ITGA5) signaling and their hematopoietic potential improved by combining AZA with an ITGA5 inhibitor. AZA response is associated with the induction of an inflammatory response in HPCs in vivo. By molecular bar coding and tracking individual clones, we found that, although AZA alters the sub-clonal contribution to different lineages, founder clones are not eliminated and continue to drive hematopoiesis even in complete responders
Hardware Commissioning of the Refurbished ALPI Linac at INFN-LNL to Serve as SPES Exotic Beam Accelerator
Abstract
The ALPI linac at INFN-LNL was substantially refurbished in 2018, especially in view of its use as secondary accelerator for exotic species in the framework of the SPES project. In particular: 10 magnetic triplets were replaced with higher gradient ones; two cryomodules with quarter wave resonator were moved from the PIAVE injector to ALPI, so as to make them available both for exotic and stable beams; the cryogenic plant was renovated; the whole linac, its injector and its beam lines were eventually realigned via LASER tracking (LT). The expected outcome of the refurbishment project is a larger beam transmission (crucial for the efficient transport of the unavoidably low current exotic beams) and improved overall reliability so as to further extend the lifetime of an already 25 years old machine. The hardware commissioning of this new configuration will be reported
The new ECR charge breeder for the Selective Production of Exotic Species project at INFNâLaboratori Nazionali di Legnaro
International audienceThe Selective Production of Exotic Species (SPES) project is an ISOL facility under construction at Istituto Nazionale di Fisica NucleareâLaboratori Nationali di Legnaro (INFN-LNL). 1+ radioactive ions, produced and extracted from the target-ion-source system, will be charge bred to high charge states by an ECR charge breeder (SPES-CB): the project will adopt an upgraded version of the PHOENIX charge breeder, developed since about twenty years by the Laboratoire de Physique Subatomique et de Cosmologie (LPSC). The collaboration between LNL and LPSC started in 2010 with charge breeding experiments performed on the LPSC test bench and led, in June 2014, to the signature of a Research Collaboration Agreement for the delivery of a complete charge breeder and ancillaries, satisfying the SPES requirements. Important technological aspects were tackled during the construction phase, as, for example, beam purity issues, electrodes alignment, and vacuum sealing. This phase was completed in spring 2015, after which the qualification tests were carried out at LPSC on the 1+/q+ test stand. This paper describes the characteristics of the SPES-CB, with particular emphasis on the results obtained during the qualification tests: charge breeding of Ar, Xe, Rb, and Cs satisfied the SPES requirements for different intensities of the injected 1+ beam, showing very good performances, some of which are âbest everâ for this device
Realization and simulations of the new SPES Beam Cooler
International audienceIn order to allow a good separation of isotopes in a High Resolution Mass Spectrometer (HRMS), the transverse emittance and the energy spread of the beam should have very low values, for this reason a Beam Cooler (BC) is planned to be located between the ISOL target, i.e. the beam source, and the HRMS in the new project Selective Production of Exotic Species (SPES). In the SPES project the spectrometer resolution must be higher than dm/m=5E-5 and thus the features of the beam at the entrance of the HRMS should be at least emittance (95%, normalized) < 8.3E-3 pi mm mrad and sigma_E < 1.5eV. A new BC has been designed and realized by the Laboratoire de Physique Corpuscolaire (LPC) at Caen, France, for the SPES facility at Laboratori Nazionali di Legnaro (LNL), near Padova, Italy. BCs cool down the beam thanks to a dissipative process in which the thermal energy passes from the beam ions to another medium whose constituent is typically much lighter, Helium gas in our case. This process takes place inside a confinement system that on the one hand to limit the spread of the cooling medium, and on the other to allow the beam to continue along the required trajectory, in the presented device it is a row of radio frequency quadrupoles in an almost closed chamber. This document presents the main features of the new BC together with the results of a preliminary study where the beam dynamic has been simulated. The analysis embeds also the investigation of the gas distribution inside and outside the BC. The beam dynamic simulations are based on the Simion code while the estimation of the gas distribution is computed with MolFlow+. Simulations show that accurately setting the BC leads to a large improvement of the emittance while the energy spread still needs to be improved. Limiting the gas pressure in the acceleration zone seems to allow the required final boost
Realization and simulations of the new SPES Beam Cooler
International audienceIn order to allow a good separation of isotopes in a High Resolution Mass Spectrometer (HRMS), the transverse emittance and the energy spread of the beam should have very low values, for this reason a Beam Cooler (BC) is planned to be located between the ISOL target, i.e. the beam source, and the HRMS in the new project Selective Production of Exotic Species (SPES). In the SPES project the spectrometer resolution must be higher than dm/m=5E-5 and thus the features of the beam at the entrance of the HRMS should be at least emittance (95%, normalized) < 8.3E-3 pi mm mrad and sigma_E < 1.5eV. A new BC has been designed and realized by the Laboratoire de Physique Corpuscolaire (LPC) at Caen, France, for the SPES facility at Laboratori Nazionali di Legnaro (LNL), near Padova, Italy. BCs cool down the beam thanks to a dissipative process in which the thermal energy passes from the beam ions to another medium whose constituent is typically much lighter, Helium gas in our case. This process takes place inside a confinement system that on the one hand to limit the spread of the cooling medium, and on the other to allow the beam to continue along the required trajectory, in the presented device it is a row of radio frequency quadrupoles in an almost closed chamber. This document presents the main features of the new BC together with the results of a preliminary study where the beam dynamic has been simulated. The analysis embeds also the investigation of the gas distribution inside and outside the BC. The beam dynamic simulations are based on the Simion code while the estimation of the gas distribution is computed with MolFlow+. Simulations show that accurately setting the BC leads to a large improvement of the emittance while the energy spread still needs to be improved. Limiting the gas pressure in the acceleration zone seems to allow the required final boost
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