A fibre-based 2D-slit homogenizer concept for high-precision space-based spectrometer missions

The measurement accuracy of recent and future space-based imaging spectrometers with a high spectral and spatial resolution suffer from the inhomogeneity of the radiances of the observed Earth scene. The Instrument Spectral Response Function (ISRF) is distorted due to the inhomogeneous illumination from scene heterogeneity. This gives rise to a pseudo-random error on the measured spectra. In order to assess the spectral stability of the spectrograph, stringent requirements are typically defined on the ISRF such as shape knowledge and the stability of the centroid position of the spectral sample. The high level of spectral accuracy is particularly crucial for missions quantifying small variations in the total column of well-mixed trace gases like $$\hbox {CO}_{2}$$ CO 2 . In the framework of the $$\hbox {CO}_{2}$$ CO 2 Monitoring Mission (CO2M) industrial feasibility study (Phase A/B1 study), we investigated a new slit design called 2D-Slit Homogenizer (2DSH). This new concept aims to reduce the Earth scene contrast entering the instrument. The 2DSH is based on optical fibre waveguides assembled in a bundle, which scramble the light in across-track (ACT) and along-track (ALT) direction. A single fibre core dimension in ALT defines the spectral extent of the slit and the dimension in ACT represents the spatial sample of the instrument. The full swath is given by the total size of the adjoined fibres in ACT direction. In this work, we provide experimental measurement data on the stability of representative rectangular core shaped fibre as well as a preliminary pre-development of a 2DSH fibre bundle. In our study, the slit concept has demonstrated significant performance gains in the stability of the ISRF for several extreme high-contrast Earth scenes, achieving a shape stability of $$<0.5{\%}$$ < 0.5 % and a centroid stability of $$<0.25 \ \text {pm}$$ < 0.25 pm (NIR). Given this unprecedented ISRF stabilization, we conclude that the 2DSH concept efficiently desensitizes the instrument for radiometric and spectral errors with respect to the heterogeneity of the Earth scene radiance.

Optimal location of resources and Steiner symmetry in a population dynamics model in heterogeneous environments

The subject of this paper is inspired by Cantrell and Cosner (1989) and Cosner, Cuccu and Porru (2013). Cantrell and Cosner (1989) investigate the dynamics of a population in heterogeneous environments by means of diffusive logistic equations. An important part of their study consists in finding sufficient conditions which guarantee the survival of the species. Mathematically, this task leads to the weighted eigenvalue problem \(-\Delta u =\lambda m u \) in a bounded smooth domain \(\Omega\subset \mathbb{R}^N\), \(N\geq 1\), under homogeneous Dirichlet boundary conditions, where \(\lambda \in \mathbb{R}\) and \(m\in L^\infty(\Omega)\). The domain \(\Omega\) represents the environment and \(m(x)\), called the local growth rate, says where the favourable and unfavourable habitats are located. Then, Cantrell and Cosner (1989) consider a class of weights \(m(x)\) corresponding to environments where the total sizes of favourable and unfavourable habitats are fixed, but their spatial arrangement is allowed to change; they determine the best choice among them for the population to survive. In our work we consider a sort of refinement of the result above. We write the weight \(m(x)\) as sum of two (or more) terms, i.e. \(m(x)=f_1(x)+f_2(x)\), where \(f_1(x)\) and \(f_2(x)\) represent the spatial densities of the two resources which contribute to form the local growth rate \(m(x)\). Then, we fix the total size of each resource allowing its spatial location to vary. As our first main result, we show that there exists an optimal choice of \(f_1(x)\) and \(f_2(x)\) and find the form of the optimizers. Our proof relies on some results in Cosner, Cuccu and Porru (2013) and on a new property (to our knowledge) about the classes of rearrangements of functions. Moreover, we show that if \(\Omega\) is Steiner symmetric, then the best arrangement of the resources inherits the same kind of symmetry. (Actually, this is proved in the more general context of the classes of rearrangements of measurable functions.

IN-STALL COMPRESSOR PERFORMANCE AND THE EFFECTS OF REYNOLDS NUMBER

Previous research into axial compressor stall has mainly focused on stall inception and methods to extend the stable operating range. This paper considers the performance of an axial compressor beyond stall and investigates how the characteristics of stall cells depend on Reynolds number. An experimental study has been conducted using a single-stage axial compressor capable of operating across the Reynolds number range of 10,000 – 100,000. Detailed unsteady measurements have been used to measure the behaviour across a range of in-stall flow coefficients. These measurements have been used to extract the stall hysteresis and to determine the size, speed, number, and spanwise extent of the stall cells. The results show that for the stalled compressor, as Reynolds number increases, the size of the minimum stable stall cell decreases. This means that a larger change in throttle area is needed to reduce the stall cell down to a size where the compressor can recover from stall. At the design Reynolds number, the number of stall cells that form transitions from one, to two, and then to four stall cells as the flow coefficient is reduced. At lower Reynolds numbers, the two-stall-cell state becomes unstable; instead, a single stall cell transitions directly into five stall cells. As the number of stall cells increases, so do the speed of the stall cells and the total size. Further reductions in the flow coefficient cause an increase in the total size and a decrease in the stall cell speed.

The highly continuous reference genome of a leaf-chimeric red pineapple (Ananas comosus var. bracteatus f. tricolor) provides insights into elaboration of leaf color

Ananas comosus var. bracteatus f. tricolor (GL1) is a red pineapple accession whose mostly green leaves with chimeric white leaf margins turn red in spring and autumn and during flowering. It is an important ornamental plant and ideal plant research model for anthocyanin metabolism, chimeric leaf development, and photosynthesis. Here, we generated a highly contiguous chromosome-scale genome assembly for GL1 and compared it with other 3 published pineapple assemblies (var. comosus accessions MD2 and F153, and var. bracteatus accession CB5). The GL1 assembly has a total size of ∼461 Mb, with a contig N50 of ∼2.97 Mb and Benchmarking Universal Single-Copy Ortholog score of 97.3%. More than 99% of the contigs are anchored to 25 pseudochromosomes. Compared with the other 3 published pineapple assemblies, the GL1 assembly was confirmed to be more continuous. Our evolutionary analysis showed that the Bromeliaceae and Poaceae diverged from their nearest common ancestor ∼82.36 million years ago (MYA). Population structure analysis showed that while GL1 has not undergone admixture, bracteatus accession CB5 has resulted from admixture of 3 species of Ananas. Through classification of orthogroups, analysis of genes under positive selection, and analysis of presence/absence variants, we identified a series of genes related to anthocyanin metabolism and development of chimeric leaves. The structure and evolution of these genes were compared among the published pineapple assemblies with reveal candidate genes for these traits. The GL1 genome assembly and its comparisons with other 3 pineapple genome assemblies provide a valuable resource for the genetic improvement of pineapple and serve as a model for understanding the genomic basis of important traits in different pineapple varieties and other pan-cereal crops.

Quantifying transmissibility of SARS-CoV-2 and impact of intervention within long-term healthcare facilities

Estimates of the basic reproduction number ( R 0 ) for COVID-19 are particularly variable in the context of transmission within locations such as long-term healthcare (LTHC) facilities. We sought to characterize the heterogeneity of R 0 across known outbreaks within these facilities. We used a unique comprehensive dataset of all outbreaks that occurred within LTHC facilities in British Columbia, Canada as of 21 September 2020. We estimated R 0 in 18 LTHC outbreaks with a novel Bayesian hierarchical dynamic model of susceptible, exposed, infected and recovered individuals, incorporating heterogeneity of R 0 between facilities. We further compared these estimates to those obtained with standard methods that use the exponential growth rate and maximum likelihood. The total size of outbreaks varied dramatically, with range of attack rates 2%–86%. The Bayesian analysis provided an overall estimate of R 0 = 2.51 (90% credible interval 0.47–9.0), with individual facility estimates ranging between 0.56 and 9.17. Uncertainty in these estimates was more constrained than standard methods, particularly for smaller outbreaks informed by the population-level model. We further estimated that intervention led to 61% (52%–69%) of all potential cases being averted within the LTHC facilities, or 75% (68%–79%) when using a model with multi-level intervention effect. Understanding of transmission risks and impact of intervention are essential in planning during the ongoing global pandemic, particularly in high-risk environments such as LTHC facilities.

Professional moral courage and moral reasoning among nurses in clinical environments: a multivariate model

Improving ethical practice needs recognizing the relationship between moral reasoning and moral courage among nurses. We examined factors (moral reasoning, practical consideration, moral dilemmas familiarity, and demographic and work characteristics) associated with moral courage among nurses. A cross-sectional design was run at all five hospitals affiliated to Hamadan University of Medical Sciences in west of Iran. A proportionate random sampling due to the total size of the nurse population in each hospital, 224 eligible nurses were completed the study questionnaires: demographic-work characteristics, Professional Moral Courage (PMC), and Nursing Dilemma Test. The relationships were examined by multiple regression analysis. Participants reported a more than moderate level of moral reasoning and PMC (43.21±5.98 and 56.16±10.18 respectively). The multivariate model showed the nurses’ PMC is positively predisposed with moral reasoning (β=0.21, p<0.01), but negatively with practical consideration (β=-0.16, p<0.01). More moral courage was found in the nurses who were never married (p<0.001), graduated from a public university (p<0.01), working in the critical care and emergency environments, as well as night shifts (all p<0.001). Moral reasoning is a predictor of moral courage, and both should be considered in designing nursing education to improve ethical nursing practice.

Transient prophylaxis and multiple epidemic waves

<abstract><p>Public opinion and opinion dynamics can have a strong effect on the transmission rate of an infectious disease for which there is no vaccine. The coupling of disease and opinion dynamics however, creates a dynamical system that is complex and poorly understood. We present a simple model in which susceptible groups adopt or give up prophylactic behaviour in accordance with the influence related to pro- and con-prophylactic communication. This influence varies with disease prevalence. We observe how the speed of the opinion dynamics affects the total size and peak size of the epidemic. We find that more reactive populations will experience a lower peak epidemic size, but possibly a larger final size and more epidemic waves, and that an increase in polarization results in a larger epidemic.</p></abstract>

Four-Port MIMO Antenna System for 5G n79 Band RF Devices

In this article, a compact four-port MIMO antenna system resonating from 4.7–5.1 GHz on −6 dB criteria is discussed. The proposed antennas are arranged in a perpendicular manner providing diversity with good isolation characteristics. The proposed antenna was fabricated and designed on a commercially available low-cost FR-4 substrate with a relative permittivity of 4.4. The total size of the antenna is 40 × 40 mm2, and a minimum isolation of 25 dB was observed at most nearby resonating elements. The proposed antenna was fabricated and tested at an in-house facility, and the measured results agree well with the simulations. The MIMO antenna characteristics, such as the envelope correlation coefficient (ECC) among any two radiating elements, have been found to be less than 0.1, and the diversity gain (DG) value evaluated showed that the proposed antenna is well designed. Furthermore, the SAR analysis showed that the desired antenna system is safe for users, with a value of 0.94 W/Kg. The channel capacity (cc) was found to be 18.7 bps/Hz, approximately 2.7 times more than SISO systems. Through its robust and reliable performance and its peak gain of 2.8 dBi, the proposed compact antenna is a good candidate for future 5G devices.

INNOVATIVE ACTIVITY IN THE SYSTEM OF FOREIGN ECONOMIC SECURITY OF THE COUNTRY

Background. One of the main indicators of the country's economic development is its trade balance, in particular the total size and value of products that the country can adequately represent in foreign markets, ensuring reliable cash flow, balanced development of economic sectors, and, consequently, growing greatness and prosperity. In modern conditions, ensuring such a global export expansion of Ukrainian products to foreign markets, in particular European ones, is impossible without proper innovation of producers and exporters, as well as sufficient investment in planned innovation projects, which requires in-depth economic analysis and strategy in this direction. Using the latest scientific inventions and research. The aim of the article is to study and analyze the current state of Ukrainian exports to world and European markets and substantiate the possibility of differentiation of export flows in order to evenly distribute the share of exports between all industries, including engineering and high technology, etc. and move away from raw materials Materials and methods. The theoretical and methodological basis of the article is the scientific works of Ukrainian and foreign scientists on the problems of innovation development. Results. As we can see from the researched data, during the last decade there is a tendency of prevalence in the general structure of the country's exports of ferrous metallurgy and mining, which is primarily due to the strong potential of these industries inherited from Soviet times, as well as agro-industrial products. in particular, cereals and oils, which is explained by the tradition of these industries for the economy of Ukraine, and established under the Association Agreement tariff quotas for Ukrainian agricultural products in the markets of the European Union. Revolutionary tasks have been set to reduce the share in the structure of exports of these types of goods first to the critical limit of 10%, and then to the target of 5%, while maintaining and even increasing the absolute monetary value of exports of these goods, which is possible only if increasing exports by other product groups, identifying priority areas among such products while legislative incentives and creating a regulatory environment to strengthen the ability of domestic enterprises to compete in world markets, especially in the face of growing protectionism in response to the challenges of the pandemic. Conclusion. Summing up, we can conclude that Ukraine has created all the prerequisites for the implementation and implementation of all short-term and strategic plans for the domestic economy and a worthy place among participants in both European and global markets, subject to improving the scientific and educational system of industrial development, wider implementation of innovation processes, as well as the implementation of plans to diversify export flows.

Biological effectiveness of quillay (Quillaja saponaria) extracts for the control of yellow aphids (Melanaphis sacchari) in sorghum

Objective: To evaluate and define a plant extract for the control of the yellow aphid in order to prevent environmental contamination and improve crop profitability. Design/Methodology/Approach: In a sorghum plot —located in the municipality of Jantetelco, Morelos— with a high incidence of yellow aphids, three doses —2-, 4-, and 6-mL L-1 of water of Quillaja saponaria extract, 0.2-mL L-1 of water of Imidacloprid, and 10-mL L-1 of water of calcium polysulfide—, as well as an absolute control, were evaluated. The applications were carried out using a 15-L manual spray backpack, which had been previously calibrated and had a fan nozzle. A randomized block experimental design—with six treatments and four repetitions— was used. The experimental unit was made up of five 5-m long rows with 0.70 m between rows, resulting in a 17.5 m2 total area per experimental unit. The three central furrows were the useful plot, leaving 0.5 m at each end of the furrow. The total size of the experimental plot was 420 m2. Results: The biological effectiveness during the samplings was as follows: both the Quillaja saponaria (6-, 4- and 2-mL L-1 water doses) and Imidacloprid treatments had a 100% effectiveness. Study limitations/implications: This study was carried out in sorghum crops. Findings/conclusions: Treatments based on Quillaja saponaria extracts on M. sacchari in sorghum crops showed 100% biological effectiveness from the first application and no phytotoxicity was observed in any treatment