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New Probability Distributions in Astrophysics: XII. Truncation for the Gompertz Distribution

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Optimal interplanetary trajectories for Sun-facing ideal diffractive sails

International Journal of Astronomy and Astrophysics（天文学与天体物理学国际期刊） 2024年第2期 101页

作者： lorenzo Zaninetti

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Astrodynamics 2023年第3期7卷 285-299页

作者： Alessandro A.Quarta Giovanni Mengali Marco Bassetto lorenzo Niccolai Department of Civil and Industrial Engineering University of PisaI-56122 PisaItaly

A diffractive sail is a solar sail whose exposed surface is covered by an advanced diffractive metamaterial film with engineered optical properties. This study examines the optimal performance of a diffractive solar sail with a Sun-facing attitude in a typical orbit-to-orbit heliocentric transfer. A Sun-facing attitude, which can be passively maintained through the suitable design of the sail shape, is obtained when the sail nominal plane is perpendicular to the Sun–spacecraft line. Unlike an ideal reflective sail, a Sun-facing diffractive sail generates a large transverse thrust component that can be effectively exploited to change the orbital angular momentum. Using a recent thrust model, this study determines the optimal control law of a Sun-facing ideal diffractive sail and simulates the minimum transfer times for a set of interplanetary mission scenarios. It also quantifies the performance difference between Sun-facing diffractive sail and reflective sail. A case study presents the results of a potential mission to the asteroid 16 Psyche.

关键词： diffractive solar sail Sun-facing sail interplanetary transfer trajectory optimization

Transport in Astrophysics: VI. Ultra-High Energy Cosmic Rays

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Analysis of the cryptocurrency market using different prototype-based clustering techniques

International Journal of Astronomy and Astrophysics（天文学与天体物理学国际期刊） 2024年第1期 65页

作者： lorenzo Zaninetti

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Financial Innovation 2022年第1期8卷 141-186页

作者： Luis lorenzo Javier Arroyo Un iversidad Complute nse de Madrid Facultad de Estudios Estadisticos Madrid MadridSpain

Since the emergence of Bitcoin,cryptocurrencies have grown significantly,not only in terms of capitalization but also in ***,the cryptocurrency market can be a conducive arena for investors,as it offers many ***,it is difficult to *** study aims to describe,summarize,and segment the main trends of the entire cryptocurrency market in 2018,using data analysis ***-ingly,we propose a new clustering-based methodology that provides complementary views of the financial behavior of cryptocurrencies,and one that looks for associations between the clustering results,and other factors that are not involved in ***,the methodology involves applying three different partitional clustering algorithms,where each of them use a different representation for cryptocurrencies,namely,yearly mean,and standard deviation of the returns,distribution of returns that have not been applied to financial markets previously,and the time series of *** each representation provides a different outlook of the market,we also examine the integration of the three clustering results,to obtain a fine-grained analysis of the main trends of the *** conclusion,we analyze the association of the clustering results with other descriptive features of cryptocurrencies,including the age,technological attributes,and financial ratios derived from *** will help to enhance the profiling of the clusters with additional descriptive insights,and to find associations with other ***,this study describes the whole market based on graphical information,and a scalable methodology that can be reproduced by investors who want to understand the main trends in the market quickly,and those that look for cryptocurrencies with different financial *** our analysis of the 2018 and 2019 for extended period,we found that the market can be typically segmented in few clusters(five or less),and even considering the

关键词： Fintech Unsupervised machine learning Cryptocurrency Electronic market Clustering Investment portfolios

Organic matter quality of forest floor as a driver of C and P dynamics in acacia and eucalypt plantations established on a Ferralic Arenosols, Congo

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Forest Ecosystems 2020年第3期7卷 511-525页

作者： Lydie-Stella Koutika lorenzo Cafiero Annamaria Bevivino Agustín Merino Research Centre on the Durability and the Productivity of Industrial Plantations(CRDPI) Av.Ma Loango Moe Poaty BP 1291Pointe-NoireRepublic of the Congo Department for Sustainability Biotechnologies and Agroindustry DivisionLaboratory for AgriFood SustainabilityQuality and SafetyItalian National Agency for New TechnologiesEnergy and Sustainable Economic DevelopmentENEACasaccia Research CentreVia Anguillarese301-00123RomeItaly Department for Sustainability Division Resource EfficiencyLaboratory Technologies for the ReuseRecyclingRecovery and valorisation of Waste and MaterialsItalian National Agency for New TechnologiesEnergy and Sustainable Economic DevelopmentENEACasaccia Research Centre00123RomeItaly Department of Soil Science and Agricultural Chemistry University of Santiago de Compostela2702LugoSpain

Background: Land-use change and forest management may alter soil organic matter(SOM) and nutrient dynamics,due in part to alterations in litter input and quality. Acacia was introduced in eucalypt plantations established in the Congolese coastal plains to improve soil fertility and tree growth. Eucalypt trees were expected to benefit from N2 fixed by acacia. However, some indicators suggest a perturbation in SOM and P dynamics might affect the sustainability of the system in the medium and long term. In tropical environments, most of the nutrient processes are determined by the high rates of organic matter(OM) mineralization. Therefore, SOM stability might play a crucial role in regulating soil-plant processes. In spite of this, the relationship between SOM quality, C and other nutrient dynamics are not well understood. In the present study, OM quality and P forms in forest floor and soil were investigated to get more insight on the C and P dynamics useful to sustainable management of forest ***: Thermal analysis(differential scanning calorimetry(DSC) and thermogravimetry(TGA)) and nuclear magnetic resonance(solid state13 C CPMASS and NMR and31 P-NMR) spectroscopy have been applied to partially decomposed forest floor and soils of pure acacia and eucalypt, and mixed-species acacia-eucalypt ***: Thermal analysis and13 C NMR analysis revealed a more advanced stage of humification in forest floor of acacia-eucalypt stands, suggesting a greater microbial activity in its litter. SOM were related to the OM recalcitrance of the forest floor, indicating this higher microbial activity of the forest floor in this stand might be favouring the incorporation of C into the mineral ***: In relation with the fast mineralization in this environment, highly soluble orthophosphate was the dominant P form in both forest floor and soils. However, the mixed-species forest stands immobilized greater P in organic forms, preventing the P losses by lea

关键词： Mixed-species plantations Soil chemical stability Organic P Forest ecosystems Potential climate change mitigation

Nutritional Supplement Ocoxin® Combined with Gemcitabine-Based Chemotherapy in Patients with Advanced Pancreatic Adenocarcinoma

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Open Journal of Gastroenterology 2024年第8期14卷 267-287页

作者： Mayté Lima-Pérez Jorge Luis Soriano-García Masiel González-Meisozo Jorge Luis Soriano-lorenzo Vilma Fleites-Calvo Dunia Morales-Morgado Carlos Domínguez-Álvarez Iván Ramón-Concepción Raidel Rodríguez-Barrios Alicia Tarinas-Reyes Ivis Mendoza-Hernández Rolando Uranga-Piña Clinical Oncology Department Ameijeiras Hospital Havana Cuba Clinical Pathology Department Ameijeiras Hospital Havana Cuba Clinical Section National Coordinating Centre for Clinical Trials Havana Cuba Biostatistics Section National Coordinating Centre for Clinical Trials Havana Cuba

Background: the quality of life (QoL) of patients with pancreatic ductal adenocarcinoma (PDAC), with its limited survival, can be affected by chemotherapy-induced toxicity. The main objective was to evaluate the effect of introducing ocoxin oral solution (OOS) in combination with standard therapy on quality of life. Methods: Thirty patients were enrolled in an exploratory, prospective, single-centre clinical trial in the oncology department of “Hermanos Ameijeiras” University Hospital in Havana, Cuba. Quality of life was measured using the EORTC QLQ-C30 questionnaire and toxicity was assessed using the NCI-CTC-AE classification version 5.0. Results: There was stability in the scores over time for overall QoL and the functional scale criteria, while in terms of symptoms, fatigue, pain and loss of appetite were reduced. No grade 3 - 4 adverse events (AEs) were recorded, and only 14.9% of toxicities were classified as grade 2, and these were considered to be unrelated to OOS. Biochemical and nutritional parameters were normalised at 12 months compared to the baseline values. Conclusions: This clinical study is the first report of the use of OOS in patients with advanced pancreatic cancer, and demonstrates that it is able to maintain optimal quality of life with reduced severity of toxicity during and after combination treatment with gemcitabine-based chemotherapy.

关键词： EORTC QLQ-C30 Ocoxin Chemotherapy Pancreatic Cancer Quality of Life

Online risk‑based portfolio allocation on subsets of crypto assets applying a prototype‑based clustering algorithm

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Financial Innovation 2023年第1期9卷 797-836页

作者： Luis lorenzo Javier Arroyo Faculty of Statistic Studies Complutense UniversityAvda.Puerta de Hierros/n28040 MadridSpain

Mean-variance portfolio optimization models are sensitive to uncertainty in risk-return estimates,which may result in poor out-of-sample *** particular,the estimates may suffer when the number of assets considered is high and the length of the return time series is not sufficiently *** is precisely the case in the cryptocur-rency market,where there are hundreds of crypto assets that have been traded for a few *** propose enhancing the mean-variance(MV)model with a pre-selection stage that uses a prototype-based clustering algorithm to reduce the number of crypto assets considered at each investment *** the pre-selection stage,we run a prototype-based clustering algorithm where the assets are described by variables representing the profit-risk *** prototypes of the clustering partition are auto-matically examined and the one that best suits our risk-aversion preference is *** then run the MV portfolio optimization with the crypto assets of the selected *** proposed approach is tested for a period of 17 months in the whole cryp-tocurrency market and two selections of the cryptocurrencies with the higher market capitalization(175 and 250 cryptos).We compare the results against three methods applied to the whole market:classic MV,risk parity,and hierarchical risk parity *** also compare our results with those from investing in the market index *** simulation results generally favor our proposal in terms of profit and risk-profit financial *** result reaffirms the convenience of using machine learning methods to guide financial investments in complex and highly-volatile environments such as the cryptocurrency market.

关键词： Fintech Mean-variance Cryptocurrency Electronic market Portfolio allocation model Clustering

A Relaxation Scheme for Solving the Boltzmann Equation Based on the Chapman-Enskog Expansion

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Acta Mathematicae Applicatae Sinica 2002年第1期18卷 37-62页

作者： Shi Jin lorenzo Pareschi Marshall Slemrod Department of Mathematics University of WisconsinMadisonVan Vleck HallWI 53706USADepartment of MathematicsUniversity of FerraraVia Machiavelli 35 I-44100Italy & Department of MathematicsUniversity of Wisconsin-MadisonVan Vleck HallWI 53706USA.Department of MathematicsUniversity of Wisconsin-MadisonMadisonWI 53715-1149USA.

In [16] a visco-elastic relaxation system, called the relaxed Burnett system, was proposed by Jin and Slemrod as a moment approximation to the Boltzmann equation. The relaxed Burnett system is weakly parabolic, has a linearly hyperbolic convection part, and is endowed with a generalized entropy inequality. It agrees with the solution of the Boltzmann equation up to the Burnett order via the Chapman-Enskog expansion. We develop a one-dimensional non-oscillatory numerical scheme based on the relaxed Burnett system for the Boltzmann equation. We compare numerical results for stationary shocks based on this relaxation scheme, and those obtained by the DSMC (Direct Simulation Monte Carlo), by the Navier-Stokes equations and by the extended thermodynamics with thirteen moments (the Grad equations). Our numerical experiments show that the relaxed Burnett gives more accurate approximations to the shock profiles of the Boltzmann equation obtained by the DSMC, for a range of Mach numbers for hypersonic flows, than those obtained by the other hydrodynamic systems.

关键词： Boltzmann equation Chapman-Enskog expansion Burnett equations relaxation central schemes

Protein Shuttle between Nucleus and Cytoplasm:New Paradigms in the ABI5-dependent ABA Responses

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Molecular Plant 2019年第11期12卷 1425-1427页

作者： Inmaculada Sanchez-Vicente Pablo Albertos Oscar lorenzo Dpto.de Botanica y Fisiologia Vegetal Instituto Hispano-Luso de Investigaciones Agrarias(CIALE)Facultad de BiologiaUniversidad de SalamancaC/Rio Duero 1237185 SalamancaSpain Present address:Biotechnology in Horticultural Crops TU Munchen-WeihenstephanLiesel-Beckmann-Strasse 185354 FreisingGermany

Plant survival depends on seed germination,progression through post-germinative developmental checkpoints,and adaptation to abiotic *** these processes underlie a tightly controlled regulation by the stress hormone abscisic acid(ABA)at different levels,even though the main research focuses on changes in transcript and protein ***,protein fate undergoes complex readjustments that allow signal transduction to be integrated into physiological *** them,protein redox status,stability,capacity of oligomerization,formation of complexes,and subcellular compartmentalization become key points for plant reprogramming against stresses to acquire an optimal *** this Spotlight,we highlight and discuss the latest advances in dissecting the mechanisms driving protein dynamics of nucleocytoplasmic trafficking in the cell and its relevance for regulating the stability of ABI5 and the ABI5-dependent AB A signaling pathway(Figure 1).

关键词： Figure driving programming