Searching for optimal variables in real multivariate stochastic data

By implementing a recent technique for the determination of stochastic eigendirections of two coupled stochastic variables, we investigate the evolution of fluctuations of NO2 concentrations at two monitoring stations in the city of Lisbon, Portugal. We analyze the stochastic part of the measurements recorded at the monitoring stations by means of a method where the two concentrations are considered as stochastic variables evolving according to a system of coupled stochastic differential equations. Analysis of their structure allows for transforming the set of measured variables to a set of derived variables, one of them with reduced stochasticity. For the specific case of NO2 concentration measures, the set of derived variables are well approximated by a global rotation of the original set of measured variables. We conclude that the stochastic sources at each station are independent from each other and typically have amplitudes of the order of the deterministic contributions. Such findings show significant limitations when predicting such quantities. Still, we briefly discuss how predictive power can be increased in general in the light of our methods

Solid behavior of anisotropic rigid frictionless bead assemblies

We investigate the structure and mechanical behavior of assemblies of frictionless, nearly rigid equal-sized beads, in the quasistatic limit, by numerical simulation. Three different loading paths are explored: triaxial compression, triaxial extension and simple shear. Generalizing recent results [1], we show that the material, despite rather strong finite sample size effects, is able to sustain a finite deviator stress in the macroscopic limit, along all three paths, without dilatancy. The shape of the yield surface is adequately described by a Lade-Duncan (rather than Mohr-Coulomb) criterion. While scalar state variables keep the same values as in isotropic systems, fabric and force anisotropies are each characterized by one parameter and are in one-to-one correspondence with principal stress ratio along all three loading paths.The anisotropy of the pair correlation function extends to a distance between bead surfaces on the order of 10% of the diameter. The tensor of elastic moduli is shown to possess a nearly singular, uniaxial structure related to stress anisotropy. Possible stress-strain relations in monotonic loading paths are also discussed

The structure of Chariklo's rings from stellar occultations

Two narrow and dense rings (called C1R and C2R) were discovered around the Centaur object (10199) Chariklo during a stellar occultation observed on 2013 June 3. Following this discovery, we planned observations of several occultations by Chariklo's system in order to better characterize the physical properties of the ring and main body. Here, we use 12 successful occulations by Chariklo observed between 2014 and 2016. They provide ring profiles (physical width, opacity, edge structure) and constraints on the radii and pole position. Our new observations are currently consistent with the circular ring solution and pole position, to within the $\pm 3.3$ km formal uncertainty for the ring radii derived by Braga-Ribas et al. The six resolved C1R profiles reveal significant width variations from $\sim 5$ to 7.5 km. The width of the fainter ring C2R is less constrained, and may vary between 0.1 and 1 km. The inner and outer edges of C1R are consistent with infinitely sharp boundaries, with typical upper limits of one kilometer for the transition zone between the ring and empty space. No constraint on the sharpness of C2R's edges is available. A 1$\sigma$ upper limit of $\sim 20$ m is derived for the equivalent width of narrow (physical width <4 km) rings up to distances of 12,000 km, counted in the ring plane

Phytonanofabrication: Methodology and Factors Affecting Biosynthesis of Nanoparticles

The greener way of producing silver nanoparticles is the easiest, cheapest and most efficient way of producing large-scale nanoparticles that have no adverse effect on the environment. The nanosynthesis using various methodologies and the biological synthesis of silver nanoparticles have been discussed in detail. Plant extracts have been known to be competent for the extracellular biosynthesis of silver nanoparticles suggested by the various publications. Further, effects of various sources and methods on nanoparticle synthesis have been examined. Additionally, the impact of conditions such as dark, light, heating, boiling, sonication, autoclave on the size and shape of colloidal nanoparticles has been analyzed. Moreover, effects of specific parameters such as leaf extract concentration, AgNO3, reaction temperature, pH, light and stirring time for nanoparticle synthesis are discussed, and the impact of silver nanoparticles on plant physiology has examined

Primary diffuse large B-cell lymphoma of the breast: prognostic factors and outcomes of a study by the International Extranodal Lymphoma Study Group

Background: Primary diffuse large B-cell lymphoma (DLBCL) of breast is rare. We aimed to define clinical features, prognostic factors, patterns of failure, and treatment outcomes. Patients and methods: A retrospective international study of 204 eligible patients presenting to the International Extranodal Lymphoma Study Group-affiliated institutions from 1980 to 2003. Results: Median age was 64 years, with 95% of patients presenting with unilateral disease. Median overall survival (OS) was 8.0 years, and median progression-free survival 5.5 years. In multifactor analysis, favourable International Prognostic Index score, anthracycline-containing chemotherapy, and radiotherapy (RT) were significantly associated with longer OS (each P ≤ 0.03). There was no benefit from mastectomy, as opposed to biopsy or lumpectomy only. At a median follow-up time of 5.5 years, 37% of patients had progressed—16% in the same or contralateral breast, 5% in the central nervous system, and 14% in other extranodal sites. Conclusions: The combination of limited surgery, anthracycline-containing chemotherapy, and involved-field RT produced the best outcome in the pre-rituximab era. A prospective trial on the basis of these results should be pursued to confirm these observations and to determine whether the impact of rituximab on the patterns of relapse and outcome parallels that of DLBCL presenting at other site

Constraints on Charon's Orbital Elements from the Double Stellar Occultation of 2008 June 22

The original publication is available at http://iopscience.iop.org/1538-3881/International audiencePluto and its main satellite, Charon, occulted the same star on 2008 June 22. This event was observed from Australia and La Réunion Island, providing the east and north Charon Plutocentric offset in the sky plane (J2000): X= + 12,070.5 ± 4 km (+ 546.2 ± 0.2 mas), Y= + 4,576.3 ± 24 km (+ 207.1 ± 1.1 mas) at 19:20:33.82 UT on Earth, corresponding to JD 2454640.129964 at Pluto. This yields Charon's true longitude L= 153.483 ± 0fdg071 in the satellite orbital plane (counted from the ascending node on J2000 mean equator) and orbital radius r= 19,564 ± 14 km at that time. We compare this position to that predicted by (1) the orbital solution of Tholen & Buie (the "TB97" solution), (2) the PLU017 Charon ephemeris, and (3) the solution of Tholen et al. (the "T08" solution). We conclude that (1) our result rules out solution TB97, (2) our position agrees with PLU017, with differences of ΔL= + 0.073 ± 0fdg071 in longitude, and Δr= + 0.6 ± 14 km in radius, and (3) while the difference with the T08 ephemeris amounts to only ΔL= 0.033 ± 0fdg071 in longitude, it exhibits a significant radial discrepancy of Δr= 61.3 ± 14 km. We discuss this difference in terms of a possible image scale relative error of 3.35 × 10-3in the 2002-2003 Hubble Space Telescope images upon which the T08 solution is mostly based. Rescaling the T08 Charon semi-major axis, a = 19, 570.45 km, to the TB97 value, a = 19636 km, all other orbital elements remaining the same ("T08/TB97" solution), we reconcile our position with the re-scaled solution by better than 12 km (or 0.55 mas) for Charon's position in its orbital plane, thus making T08/TB97 our preferred solution

A laboratory study of anisotropic geomaterials incorporating recent micromechanical understanding

This paper presents an experimental investigation revisiting the anisotropic stress–strain–strength behaviour of geomaterials in drained monotonic shear using hollow cylinder apparatus. The test programme has been designed to cover the effect of material anisotropy, preshearing, material density and intermediate principal stress on the behaviour of Leighton Buzzard sand. Experiments have also been performed on glass beads to understand the effect of particle shape. This paper explains phenomenological observations based on recently acquired understanding in micromechanics, with attention focused on strength anisotropy and deformation non-coaxiality, i.e. non-coincidence between the principal stress direction and the principal strain rate direction. The test results demonstrate that the effects of initial anisotropy produced during sample preparation are significant. The stress–strain–strength behaviour of the specimen shows strong dependence on the principal stress direction. Preloading history, material density and particle shape are also found to be influential. In particular, it was found that non-coaxiality is more significant in presheared specimens. The observations on the strength anisotropy and deformation non-coaxiality were explained based on the stress–force–fabric relationship. It was observed that intermediate principal stress parameter b(b = (σ2 − σ3)/(σ1 − σ3)) has a significant effect on the non-coaxiality of sand. The lower the b-value, the higher the degree of non-coaxiality is induced. Visual inspection of shear band formed at the end of HCA testing has also been presented. The inclinations of the shear bands at different loading directions can be predicted well by taking account of the relative direction of the mobilized planes to the bedding plane

Strategies for tropical forest protection and sustainable supply chains: challenges and opportunities for alignment with the UN sustainable development goals

Governance for sustainable development increasingly involves diverse stakeholder groups, with the promise of enhanced legitimacy and effectiveness in decision-making and implementation. The UN sustainable development goals (SDGs) emphasise the important role of multiple (non-state) actors, including businesses and non-governmental organisations, including in efforts to ensure the sustainability of supply chains, and to reduce tropical deforestation and forest degradation. This paper critically analyses sustainability strategies to examine how the UN SDG agendas related to ‘sustainable supply chains’ and ‘tropical forest protection’ are framed and enacted by two contrasting non-state actors: (1) Instituto Centro de Vida (ICV), an NGO in Brazil working to address deforestation, including by supporting farmers to produce commodities, and (2) Unilever, a global consumer goods manufacturer and major buyer of such commodities. By identifying areas of variability in the discursive techniques used by ICV and Unilever, we unearth particular power dynamics that can shape the processes and outcomes of sustainability strategies. This paper finds that the two organisations use diverse strategies at different levels of governance, both participate actively in multi-stakeholder forums to advance their organisations’ goals, but have divergent framings of ‘sustainability’. Despite being considered ‘non-state’ actors, the strategies of the two organisations examined both reflect, and influence, the structural effects of the state in the implementation of non-state organisations’ strategies, and progress towards the SDGs. Although there is alignment of certain strategies related to tropical forest protection, in some cases, there is a risk that more sustainable, alternative approaches to governing forests and supply chains may be excluded

Numerical analysis of different heating systems for warm sheet metal forming

The main goal of this study is to present an analysis of different heating methods frequently used in laboratory scale and in the industrial practice to heat blanks at warm temperatures. In this context, the blank can be heated inside the forming tools (internal method) or using a heating system (external method). In order to perform this analysis, a finite element model is firstly validated with the simulation of the direct resistance system used in a Gleeble testing machine. The predicted temperature was compared with the temperature distribution recorded experimentally and a good agreement was found. Afterwards, a finite element model is used to predict the temperature distribution in the blank during the heating process, when using different heating methods. The analysis also includes the evaluation of a cooling phase associated to the transport phase for the external heating methods. The results of this analysis show that neglecting the heating phase and a transport phase could lead to inaccuracies in the simulation of the forming phase.The authors gratefully acknowledge the financial support of the Portuguese Foundation for Science and Technology (FCT) under project PTDC/EMS-TEC/1805/2012 and by FEDER funds through the program COMPETE—Programa Operacional Factores de Competitividade, under the project CENTRO-07-0224-FEDER-002001 (MT4MOBI). The authors would like to thank Prof. A. Andrade-Campos for helpful contributions on the development of the finite element code presented in this work.info:eu-repo/semantics/publishedVersio

AD51B in Familial Breast Cancer

Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C&gt;T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk