Tracking Target Signal Strengths on a Grid using Sparsity

Multi-target tracking is mainly challenged by the nonlinearity present in the measurement equation, and the difficulty in fast and accurate data association. To overcome these challenges, the present paper introduces a grid-based model in which the state captures target signal strengths on a known spatial grid (TSSG). This model leads to \emph{linear} state and measurement equations, which bypass data association and can afford state estimation via sparsity-aware Kalman filtering (KF). Leveraging the grid-induced sparsity of the novel model, two types of sparsity-cognizant TSSG-KF trackers are developed: one effects sparsity through $\ell_1$-norm regularization, and the other invokes sparsity as an extra measurement. Iterative extended KF and Gauss-Newton algorithms are developed for reduced-complexity tracking, along with accurate error covariance updates for assessing performance of the resultant sparsity-aware state estimators. Based on TSSG state estimates, more informative target position and track estimates can be obtained in a follow-up step, ensuring that track association and position estimation errors do not propagate back into TSSG state estimates. The novel TSSG trackers do not require knowing the number of targets or their signal strengths, and exhibit considerably lower complexity than the benchmark hidden Markov model filter, especially for a large number of targets. Numerical simulations demonstrate that sparsity-cognizant trackers enjoy improved root mean-square error performance at reduced complexity when compared to their sparsity-agnostic counterparts.Comment: Submitted to IEEE Trans. on Signal Processin

Refinement and standardization of storage procedures for clonal crops. Global Public Goods Phase 2: Part 1. Project landscape and general status of clonal crop in vitro conservation technologies

Among the collective actions of the World Bank-funded Global Public Goods Phase II Project (GPG2), the following collaborative activity: “Refinement and standardization of storage procedures for clonal crops” was given to the CGIAR’s In Vitro Genebanks, represented by the Clonal Crop Task Force (CCTF) composed of genetic resources research staff from the four centres: Bioversity International, CIAT, CIP and IITA. These hold the in trust collections of Musa, cassava, potato, sweetpotato, yam and Andean root and tuber crops (ARTCs). The overarching aims of this activity were to: (1) review the status of vitro conservation in the context of the GPG2 project with an emphasis on the mandated clonal crops; (2) survey the facilities, storage protocols and practices of CGIAR’s clonal crop genebanks; (3) collate and review this information with a view to developing quality and risk management systems to support the production and validation of multi-crop best practice guidelines. Outputs from this activity are designated as a three part ‘trilogy’: Part I, entitled “Project landscape and general status of clonal crop in vitro conservation technologies” introduces the GPG2 project within the CGIAR landscape and overviews the status of in vitro plant conservation in the wider conservation community of practice. This part describes the role of risk and quality management for the effective maintenance of in vitro genebanks in the context of research and the development and validation of best practices

Refinement and standardization of storage procedures for clonal crops. Global Public Goods Phase 2. Part 2: Status of in vitro conservation technologies for: Andean root and tuber crops, cassava, Musa, potato, sweetpotato and yam

Among the collective actions of the World Bank-funded Global Public Goods Phase II Project (GPG2), the following collaborative activity: “Refinement and standardization of storage procedures for clonal crops” was given to the CGIAR’s In Vitro Genebanks, represented by the Clonal Crop Task Force (CCTF) composed of genetic resources research staff from the four centres: Bioversity International, CIAT, CIP and IITA. These hold the in trust collections of Musa, cassava, potato, sweetpotato, yam and Andean root and tuber crops (ARTCs). The overarching aims of this activity were to: (1) review the status of vitro conservation in the context of the GPG2 project with an emphasis on the mandated clonal crops; (2) survey the facilities, storage protocols and practices of CGIAR’s clonal crop genebanks; (3) collate and review this information with a view to developing quality and risk management systems to support the production and validation of multi-crop best practice guidelines. Outputs from this activity are designated as a three part ‘trilogy’: Part II, “Status of in vitro conservation technologies for Andean root and tuber crops, cassava, Musa, potato, sweetpotato and yam” provides a status update on the mandate clonal crops. As tasked by GPG2, it includes lessons learnt, critical point analyses and the priority research needs of CGIAR’s in vitro genebanks

Refinement and standardization of storage procedures for clonal crops. Global Public Goods Phase 2. Part 3: Multi-crop guidelines for developing in vitro conservation best practices for clonal crops

Among the collective actions of the World Bank-funded Global Public Goods Phase II Project (GPG2), the following collaborative activity: “Refinement and standardization of storage procedures for clonal crops” was given to the CGIAR’s In Vitro Genebanks, represented by the Clonal Crop Task Force (CCTF) composed of genetic resources research staff from the four centres: Bioversity International, CIAT, CIP and IITA. These hold the in trust collections of Musa, cassava, potato, sweetpotato, yam and Andean root and tuber crops (ARTCs). The overarching aims of this activity were to: (1) review the status of vitro conservation in the context of the GPG2 project with an emphasis on the mandated clonal crops; (2) survey the facilities, storage protocols and practices of CGIAR’s clonal crop genebanks; (3) collate and review this information with a view to developing quality and risk management systems to support the production and validation of multi-crop best practice guidelines. Outputs from this activity are designated as a three part ‘trilogy’: Part III, “Multi-crop guidelines for developing in vitro conservation best practices for clonal crops” is a compilation of quality and risk management best practices and guidelines from both plant and other bioresources communities. This collective knowledge provided the foundation for developing the GPG2 multi-crop best practice guidelines. They are compiled in two parts. Section I comprises general operational guidelines for quality and risk management in in vitro plant genebanks. Section II provides generic, multi-crop technical guidelines for the medium-term (slow growth) and long-term (cryopreservation) storage of crop germplasm held in In vitro active genebanks (IVAGs) and In vitro base genebanks (IVBGs) respectively

MARS spectral molecular imaging of lamb tissue: data collection and image analysis

Spectral molecular imaging is a new imaging technique able to discriminate and quantify different components of tissue simultaneously at high spatial and high energy resolution. Our MARS scanner is an x-ray based small animal CT system designed to be used in the diagnostic energy range (20 to 140 keV). In this paper, we demonstrate the use of the MARS scanner, equipped with the Medipix3RX spectroscopic photon-processing detector, to discriminate fat, calcium, and water in tissue. We present data collected from a sample of lamb meat including bone as an illustrative example of human tissue imaging. The data is analyzed using our 3D Algebraic Reconstruction Algorithm (MARS-ART) and by material decomposition based on a constrained linear least squares algorithm. The results presented here clearly show the quantification of lipid-like, water-like and bone-like components of tissue. However, it is also clear to us that better algorithms could extract more information of clinical interest from our data. Because we are one of the first to present data from multi-energy photon-processing small animal CT systems, we make the raw, partial and fully processed data available with the intention that others can analyze it using their familiar routines. The raw, partially processed and fully processed data of lamb tissue along with the phantom calibration data can be found at [http://hdl.handle.net/10092/8531].Comment: 11 pages, 6 fig

Instability, investment, disasters, and demography: natural disasters and fertility in Italy (1820–1962) and Japan (1671–1965)

This article examines whether natural disasters affect fertility—a topic little explored but of policy importance given relevance to policies regarding disaster insurance, foreign aid, and the environment. The identification strategy uses historic regional data to exploit natural variation within each of two countries: one European country—Italy (1820–1962), and one Asian country—Japan (1671–1965). The choice of study settings allows consideration of Jones’ (The European miracle, Cambridge University Press, Cambridge, 1981) theory that preindustrial differences in income and population between Asia and Europe resulted from the fertility response to different environmental risk profiles. According to the results, short-run instability, particularly that arising from the natural environment, appears to be associated with a decrease in fertility—thereby suggesting that environmental shocks and economic volatility are associated with a decrease in investment in the population size of future generations. The results also show that, contrary to Jones’ (The European miracle, Cambridge University Press, Cambridge, 1981) theory, differences in fertility between Italy and Japan cannot be explained away by disaster proneness alone. Research on the effects of natural disasters may enable social scientists and environmentalists alike to better predict the potential effects of the increase in natural disasters that may result from global climate change

Belle II Executive Summary

Belle II is a Super $B$ Factory experiment, expected to record 50 ab$^{-1}$ of $e^+e^-$ collisions at the SuperKEKB accelerator over the next decade. The large samples of $B$ mesons, charm hadrons, and tau leptons produced in the clean experimental environment of $e^+e^-$ collisions will provide the basis of a broad and unique flavor-physics program. Belle II will pursue physics beyond the Standard Model in many ways, for example: improving the precision of weak interaction parameters, particularly Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and phases, and thus more rigorously test the CKM paradigm, measuring lepton-flavor-violating parameters, and performing unique searches for missing-mass dark matter events. Many key measurements will be made with world-leading precision.Comment: 7 pages, to be submitted to the "Rare and Precision Measurements Frontier" of the APS DPF Community Planning Exercise Snowmass 202

Impact of Dust Source Patchiness on the Existence of a Constant Dust Flux Layer During Aeolian Erosion Events

Dust emission fluxes during wind soil erosion are usually estimated using a dust concentration vertical gradient, by assuming a constant dust flux layer between the surface and the dust measurement levels. Here, we investigate the existence of this layer during erosion events recorded in Iceland and Jordan. Size-resolved dust fluxes were estimated at three levels between 2 and 4 m using the eddy-covariance method. Dust fluxes were found mainly constant only between the two upper levels in Iceland, the lower dust flux being often stronger and richer in coarse particles, while dust fluxes in Jordan were nearly constant across all levels. The wind dynamics could not explain the absence of a constant dust flux layer in Iceland. We show that the presence of stationary dust source patches in Iceland, related to surface humidity, created a non-uniform dust layer near the surface, named dust roughness sublayer (DRSL), where individual plumes behind each patch interact but do not fully mix. The lowest dust measurement level was probably located within this sublayer while the upper ones were located above, such that there the emitted dust became spatially well-mixed. This explains near the surface in Iceland, the more intermittent dust concentration, its low correlation with the dust concentrations above, and the richer dust flux in coarse particles due to their lower deposition contribution. Our findings highlight the importance of estimating dust fluxes above a dust blending height whose characteristics depend on the dust source patchiness caused by surface humidity or the presence of sparse non-erosive elements.We acknowledge the European Research Council under the Horizon 2020 research and innovation programme through the ERC Consolidator Grant FRAGMENT (Grant agreement no 773051), and the AXA Research Fund through the AXA Chair on Sand and Dust Storms at BSC for financial support of the field campaigns in Iceland and Jordan. S. Dupont acknowledge the financial support of the Department Agroecosystem of INRAE. K. Kandler and K. Schepanski are funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—416816480; 417012665. For the Icelandic campaign, we thank the staff from the ranger station at Dreki as well as the wardens of the Dreki campsite and the Dreki mountain rescue service for their valuable support and advice. We also thank Vilhjalmur Vernharðsson and his crew from Fjalladýrð for their permanent logistic help. Without all of them, the measurement campaign would not have been successfully feasible. For the Jordanian campaign, we acknowledge efforts by the staff at Wadi Rum Protected Area, Aqaba Special Economic Zone Authority, and Directorate of Environmental Monitoring and Assessment at Ministry of Environment. We also thank the Helmholtz Association's Initiative and Networking Fund (Grant agreement no VH-NG-1533) for financial support of the field campaigns in Iceland and Jordan.Peer reviewe

Measurement of the Λc+\Lambda_c^+ lifetime

An absolute measurement of the $\Lambda^{+}_c$ lifetime is reported using $\Lambda_c^+\rightarrow pK^-\pi^+$ decays in events reconstructed from data collected by the Belle II experiment at the SuperKEKB asymmetric-energy electron-positron collider. The total integrated luminosity of the data sample, which was collected at center-of-mass energies at or near the $\Upsilon(4S)$ resonance, is 207.2~\mbox{fb}^{-1}. The result, $\tau(\Lambda^{+}_c) = 203.20 \pm 0.89 \,\mathrm{(stat)} \pm 0.77 \,\mathrm{(syst)}$ fs, is the most precise measurement to date and is consistent with previous determinations.Comment: Accepted for publication in PR

Search for an invisible Z′Z^\prime in a final state with two muons and missing energy at Belle II

The $L_{\mu}-L_{\tau}$ extension of the standard model predicts the existence of a lepton-flavor-universality-violating $Z^{\prime}$ boson that couples only to the heavier lepton families. We search for such a $Z^\prime$ through its invisible decay in the process $e^+ e^- \to \mu^+ \mu^- Z^{\prime}$. We use a sample of electron-positron collisions at a center-of-mass energy of 10.58GeV collected by the Belle II experiment in 2019-2020, corresponding to an integrated luminosity of 79.7fb$^{-1}$. We find no excess over the expected standard-model background. We set 90$\%$-confidence-level upper limits on the cross section for this process as well as on the coupling of the model, which ranges from $3 \times 10^{-3}$ at low $Z^{\prime}$ masses to 1 at $Z^{\prime}$ masses of 8$GeV/c^{2}$