Maximum a posteriori estimation through simulated annealing for binary asteroid orbit determination

This paper considers a new method for the binary asteroid orbit determination problem. The method is based on the Bayesian approach with a global optimisation algorithm. The orbital parameters to be determined are modelled through an a posteriori distribution made of a priori and likelihood terms. The first term constrains the parameters space and it allows the introduction of available knowledge about the orbit. The second term is based on given observations and it allows us to use and compare different observational error models. Once the a posteriori model is built, the estimator of the orbital parameters is computed using a global optimisation procedure: the simulated annealing algorithm. The maximum a posteriori (MAP) techniques are verified using simulated and real data. The obtained results validate the proposed method. The new approach guarantees independence of the initial parameters estimation and theoretical convergence towards the global optimisation solution. It is particularly useful in these situations, whenever a good initial orbit estimation is difficult to get, whenever observations are not well-sampled, and whenever the statistical behaviour of the observational errors cannot be stated Gaussian like.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Societ

Stringy Model of Cosmological Dark Energy

A string field theory(SFT) nonlocal model of the cosmological dark energy providing w<-1 is briefly surveyed. We summarize recent developments and open problems, as well as point out some theoretical issues related with others applications of the SFT nonlocal models in cosmology, in particular, in inflation and cosmological singularity.Comment: Talk at PASCOS 2007, to appear in the proceedings, 5 pages, late

Effective Promotion and Communication in modern Censuses: A study about 2021 Romania’s Census

This study underscores the vital importance of conducting a census to obtain accurate population data, crucial for informed decision-making in various domains. Censuses are pivotal national events, requiring effective promotion. Adapting to technological advancements and societal needs is imperative, with a shift from traditional paper questionnaires to digital tools for enhanced data quality and reduced costs. The 2021 census in Romania, organized amid the COVID-19 pandemic, introduced unique challenges and transformed communication strategies. Evolving public attitudes, influenced by factors like census complexity, question sensitivity and time constraints, underscore the need for adaptable communication and promotion approaches. This research sheds light on census promotion dynamics, social media engagement, and public perceptions, offering valuable insights for policymakers, researchers, and government agencies striving to enhance census efforts and build public trust in an increasingly digital age

Statistical inversion method for binary asteroids orbit determination

International audienceWe focus on the study of binary asteroids, which are common in the Solar system from its inner to its outer regions . These objects provide fundamental physical parameters such as mass and density, andhence clues on the early solar sytem, or ooher processes that are affecting asteroid over time. The present method of orbit computation for resolved binaries is based on Markov Chain Monte-Carlo statistical inversion technique. Particularly we use the metropolis-hasting algorithm with Thiele - Innes equation for sampling the orbital elements and system mass through the sampling observations. The method requires a minimum of four observations, made at the same tangent plane; it is of particular interest for orbit determination over short ars or with sparse data. The observations are sampled within their observationale errors with an assumed distribution. The sampling yields the whole region of possible orbits including the one that is most probable.

Rethinking the territorial pact in the context of European territorial cohesion

The authors argue through this paper, the importance of rethinking the recently abandoned tools that can be reactivated in times of crisis. EU 2020 Strategy and other EU documents create a favorable frame in order to achieve the priorities set by reconsidering the territorial pact concept. Recent documents define the partnership agreement concept, which seems to be more rigid and less flexible than the territorial pact. Having as a starter point Romania’s specifics, there are individualized 10 thematic territorial pacts and 8 global pacts. They must generate territorial synergies capable of ensuring the coherence between regions, states and the European Union as a whole

Pupils Left Behind? An Analysis on the Data from National Evaluation Exams in Romania 2023

In the 2022-2023 school year, about 47% of candidates were admitted to their first-choice high school, while 1.44% were not admitted to any school. This research paper explores the dynamics of Romania's educational landscape, focusing on the National Evaluation Exams in the 2022-2023 school year. The paper investigates the path of pupils who, despite obtaining passing final admission scores, were not assigned in the first admission round to an upper-secondary educational facility. Two crucial research questions guide this study: on one hand, how many of these students competed in a different county than their residential county? On the other hand, what similarities and differences exist among them in terms of performance at the National Exam and average scores in the lower-secondary educational cycle? The findings aim to shed light on the challenges and opportunities within Romania's education system

Metals Toxic Effects in Aquatic Ecosystems: Modulators of Water Quality

The topic of this work was based on the assessment of aquatic systems quality related to the persistent metal pollution. The use of aquatic organisms as bioindicators of metal pollution allowed the obtaining of valuable information about the acute and chronic toxicity on common Romanian aquatic species and the estimation of the environment quality. Laboratory toxicity results showed that Cd, As, Cu, Zn, Pb, Ni, Zr, and Ti have toxic to very toxic effects on Cyprinus carpio, and this observation could raise concerns because of its importance as a fishery resource. The benthic invertebrates’ analysis showed that bioaccumulation level depends on species, type of metals, and sampling sites. The metal analysis from the shells of three mollusk species showed that the metals involved in the metabolic processes (Fe, Mn, Zn, Cu, and Mg) were more accumulated than the toxic ones (Pb, Cd). The bioaccumulation factors of metals in benthic invertebrates were subunitary, which indicated a slow bioaccumulation process in the studied aquatic ecosystems. The preliminary aquatic risk assessment of Ni, Cd, Cr, Cu, Pb, As, and Zn on C. carpio revealed insignificant to moderate risk considering the measured environmental concentrations, acute and long-term effects and environmental compartment

Complete genome sequence of Photobacterium ganghwense C2.2: A new polyhydroxyalkanoate production candidate

Polyhydroxyalkanoates (PHAs) are biodegradable bioplastics that can be manufactured sustainably and represent a promising green alternative to petrochemical-based plastics. Here, we describe the complete genome of a new marine PHA-producing bacterium—Photobacterium ganghwense (strain C2.2), which we have isolated from the Black Sea seashore. This new isolate is psychrotolerant and accumulates PHA when glycerol is provided as the main carbon source. Transmission electron microscopy, specific staining with Nile Red visualized via epifluorescence microscopy and gas chromatography analysis confirmed the accumulation of PHA. This is the only PHA-producing Photobacterium for which we now have a complete genome sequence, allowing us to investigate the pathways for PHA production and other secondary metabolite synthesis pathways. The de novo assembly genome, obtained using open-source tools, comprises two chromosomes (3.5, 2 Mbp) and a megaplasmid (202 kbp). We identify the entire PHA synthesis gene cluster that encodes a class I PHA synthase, a phasin, a 3-ketothiolase, and an acetoacetyl-CoA reductase. No conventional PHA depolymerase was identified in strain C2.2, but a putative lipase with extracellular amorphous PHA depolymerase activity was annotated, suggesting that C2.2 is unable to degrade intracellular PHA. A complete pathway for the conversion of glycerol to acetyl-CoA was annotated, in accordance with its ability to convert glycerol to PHA. Several secondary metabolite biosynthetic gene clusters and a low number of genes involved in antibiotic resistance and virulence were also identified, indicating the strain's suitability for biotechnological applications