RESUMO
BACKGROUND: Beyond the massive amounts of DNA and genes transferred from the protoorganelle genome to the nucleus during the endosymbiotic event that gave rise to the plastids, stretches of plastid DNA of varying size are still being copied and relocated to the nuclear genome in a process that is ongoing and does not result in the concomitant shrinking of the plastid genome. As a result, plant nuclear genomes feature small, but variable, fraction of their genomes of plastid origin, the so-called nuclear plastid DNA sequences (NUPTs). However, the mechanisms underlying the origin and fixation of NUPTs are not yet fully elucidated and research on the topic has been mostly focused on a limited number of species and of plastid DNA. RESULTS: Here, we leveraged a chromosome-scale version of the genome of the orphan crop Moringa oleifera, which features the largest fraction of plastid DNA in any plant nuclear genome known so far, to gain insights into the mechanisms of origin of NUPTs. For this purpose, we examined the chromosomal distribution and arrangement of NUPTs, we explicitly modeled and tested the correlation between their age and size distribution, we characterized their sites of origin at the chloroplast genome and their sites of insertion at the nuclear one, as well as we investigated their arrangement in clusters. We found a bimodal distribution of NUPT relative ages, which implies NUPTs in moringa were formed through two separate events. Furthermore, NUPTs from every event showed markedly distinctive features, suggesting they originated through distinct mechanisms. CONCLUSIONS: Our results reveal an unanticipated complexity of the mechanisms at the origin of NUPTs and of the evolutionary forces behind their fixation and highlight moringa species as an exceptional model to assess the impact of plastid DNA in the evolution of the architecture and function of plant nuclear genomes.
Assuntos
Genomas de Plastídeos , Moringa oleifera , Moringa oleifera/genética , Evolução Molecular , Plastídeos/genética , Genoma de Planta , DNA de Plantas/genética , Plantas/genética , Núcleo Celular/genéticaRESUMO
BACKGROUND: Unlike Transposable Elements (TEs) and gene/genome duplication, the role of the so-called nuclear plastid DNA sequences (NUPTs) in shaping the evolution of genome architecture and function remains poorly studied. We investigate here the functional and evolutionary fate of NUPTs in the orphan crop Moringa oleifera (moringa), featured by the highest fraction of plastid DNA found so far in any plant genome, focusing on (i) any potential biases in their distribution in relation to specific nuclear genomic features, (ii) their contribution to the emergence of new genes and gene regions, and (iii) their impact on the expression of target nuclear genes. RESULTS: In agreement with their potential mutagenic effect, NUPTs are underrepresented among structural genes, although their overall transcription levels and broadness were only lower when involved exonic regions; the occurrence of plastid DNA generally did not result in a broader expression, except among those affected in introns by older NUPTs. In contrast, we found a strong enrichment of NUPTs among specific superfamilies of retrotransposons and several classes of RNA genes, including those participating in the protein biosynthetic machinery (i.e., rRNA and tRNA genes) and a specific class of regulatory RNAs. A significant fraction of NUPT RNA genes was found to be functionally expressed, thus potentially contributing to the nuclear pool. CONCLUSIONS: Our results complete our view of the molecular factors driving the evolution of nuclear genome architecture and function, and support plastid DNA in moringa as a major source of (i) genome complexity and (ii) the nuclear pool of RNA genes.
Assuntos
Genoma de Planta , Moringa oleifera , Moringa oleifera/genética , Plastídeos/genética , Núcleo Celular/genética , Produtos Agrícolas/genética , Evolução Molecular , RNA de Plantas/genética , DNA de Plantas/genética , Genes de PlantasRESUMO
The stability of the power grid's frequency is crucial for industrial, commercial, and domestic applications. The standard frequency in Europe's grid is 50 Hz and it must be as stable as possible; therefore, reliable measurement is essential to ensure that the frequency is within the limits defined in the standard EN 50160:2010. In this article, a method has been introduced for the measurement of the grid frequency through a power line harmonics radiation analysis. An extremely low-frequency magnetometer was developed with the specific purpose of monitoring, in real time, the electromagnetic field produced by electrical installations in the range from 0 to 2.2 kHz. Zero-crossing and Fast Fourier transform algorithms were applied to the output signal to calculate the grid frequency as a non-invasive method. As a final step, data for a complete month (May 2021) were compared with a commercial power quality analyzer connected to the main line to validate the results. The zero-crossing algorithm gave the best result on 3 May 2021, with a coefficient of determination (R2) of 0.9801. Therefore, the indirect measurement of the grid frequency obtained through this analysis satisfactorily fits the grid frequency.
RESUMO
An important challenge for our society is the transformation of traditional power systems to a decentralized model based on renewable energy sources. In this new scenario, advanced devices are needed for real-time monitoring and control of the energy flow and power quality (PQ). Ideally, the data collected by Internet of Thing (IoT) sensors should be shared to central cloud systems for online and off-line analysis. In this paper openZmeter (oZm) is presented as an advanced low-cost and open-source hardware device for high-precision energy and power quality measurement in low-voltage power systems. An analog front end (AFE) stage is designed and developed for the acquisition, conditioning, and processing of power signals. This AFE can be stacked on available quadcore embedded ARM boards. The proposed hardware is capable of adapting voltage signals up to 800 V AC/DC and currents up to thousands of amperes using different probes. The oZm device is described as a fully autonomous open-source system for the computation and visualization of PQ events and consumed/generated energy, along with full details of its hardware implementation. It also has the ability to send data to central cloud management systems. Given the small size of the hardware design and considering that it allows measurements under a wide range of operating conditions, oZm can be used both as bulk metering or as metering/submetering device for individual appliances. The design is released as open hardware and therefore is presented to the community as a powerful tool for general usage.
RESUMO
This study proposes an explanation for the physical power flow in planar circuits by analogy to theoretical two-dimensional circuits using a new mathematical model based on Geometric Algebra (GA) and 2D Maxwell's equations. In contrast with traditional 3D physics in the observable real world, the magnetic field can be defined as a bivector instead of an axial vector allowing to obtain the Poynting Vector directly in a 2D flat world, where physical variables of planar circuits can be obtained. This approach is presented here for the first time to the best of the author's knowledge. Previous investigations have focused on simplifications and symmetries of real 3D circuits studied mainly in the phasor and frequency domain. In this work, the electromagnetic power flow phenomenon is analyzed on a completely 2D time-domain basis and derived directly from the undisputed Maxwell equations, formulated in two dimensions. Several cases of special interest in AC multi-phase circuits are presented using the proposed technique, bringing a new simplified approach to the measurement of power flow exchange between the source and the load. It suggests a new way to understand energy propagation from a purely physical point of view.
RESUMO
Mankind has known about different parasitic diseases since ancient times. There is no doubt that parasites are the infectious agents that have caused the most deaths throughout history. But even today, parasitic diseases affect more than one billion people worldwide. In this paper, the relationship between articles published in the area of parasitology and international patents in this field from 1996 to 2019 was analyzed. For this purpose, Scopus has been used. This is a database developed by Elsevier, which, in addition to having numerous indexed journals and books, has developed SciVal, an analysis tool with which the publications that have been cited in the patents of the 5 largest patent offices in the world have been analyzed. The analysis has allowed us to study 2814 publications, to know their time trend, their Authors, Affiliations, and Countries, as well as the journals in which they have been published. Also, the topics and topic clusters related to parasitology that appear in publications cited in international patents have been known. Thus, the existence of six Topic Clusters that group 94% of all publications has been discovered. Of all of them, the Topic Cluster referring to malaria stands out above all others, with 968 articles (34% of the total), probably due to the fact that malaria continues to be, to this day, one of the great challenges for both industry and basic research throughout the world.
Assuntos
Malária , Doenças Parasitárias , Bibliometria , Bases de Dados Factuais , Humanos , Malária/epidemiologiaRESUMO
In a broad sense, science can be understood as the knowledge contained in scientific manuscripts published in scientific journals. Scientific databases index only those journals that reach certain quality standards. Therefore, research and dissemination of scientific knowledge are essential activities for the growth of science itself. The aim of this manuscript is to assess the situation of medicine and environmental sciences among the bibliometric literature and to put it in perspective with the overall bibliometric publications in all scientific fields. The main countries publishing bibliometric manuscripts are China, USA and Spain. The latter country is ranked three out of the top five institutions according to the Scopus and WoS databases. In both databases, the average scientific collaboration of the top 20 institutions offers the same result, 41%. According to Scopus, the main subject categories in which this research falls are social sciences (38%), computer science (26%) and medicine (23%), while the environmental sciences category has 8%. In the analysis of the Medicine category alone, it has been observed that 136 countries have contributions in this field. The main countries are the United States, China and the United Kingdom. In the field of medicine, the main areas studied were: Epidemiology, Pediatrics, Orthopedics, Cardiology, Neurosurgery, Radiology, Ophthalmology, Oncology, Plastic Surgery and Psychiatry. With respect to environmental sciences, less international dissemination has been found, with only 83 countries having worked in this field. The main ones are China, Spain and the United States. Regarding the top 10 institutions, it can be stated that only Spain and China are relevant. Spain focuses on sustainability and China on the environment. The result of an independent keyword analysis of all published bibliometric manuscripts has shown that the main clusters are: Mapping Science (29%), Research Productivity (23%), Medicine (20%), Environmental Sciences (12%), Psychology (7%), Nursing (6%) and Engineering (4%). In short, medicine and environmental sciences are the most relevant areas in the field of bibliometrics after social sciences and computer sciences.
Assuntos
Ciência Ambiental , Bibliometria , Criança , China , Humanos , Espanha , Reino Unido , Estados UnidosRESUMO
Investments in research and development (R&D) and innovation are expensive, and one wishes to be assured that there is positive feedback and to receive guidance on how to direct investments in the future. The social or economic benefits of investments in R&D are of particular interest to policymakers. In this regard, public expense in research, especially through universities, is sometimes being questioned. This paper establishes a measure of how research in Spain, and specifically in its universities, is involved. In this study, we have analyzed all the literature cited in the period 1998-2018 produced by Spanish institutions and which has been cited in at least one international patent, obtaining more than 40,000 publications from more than 160,000 different authors. The data have been surprisingly positive, showing that practically all public universities contribute to this subject and that there is a great deal of international collaboration, both in terms of the number of countries with which they collaborate and the prestige of the institutions involved. Regarding the specific scientific fields in which this collaboration is most relevant, biochemistry, genetics and molecular biology, and medicine together account for almost 40% of the total works. The topics most used by these publications were those of diseases or medical problems such as: Neoplams, Carcinoma, Alzheimer Disease, or human immunodeficiency virus (HIV-1). Oncology was according to the All Science Journal Classification (ASJC) the leading and central issue. Therefore, although the result of basic research is difficult to quantify, when it is observed that there is a return in fields such as medicine or global health, it can be said that it is well employed. In terms of journals from a purely bibliometric point of view, it has been observed that some journals do not have a great impact or relative position within their categories, but they do have a great relevance in this area of patent support. Therefore, it would be worthwhile to set up a rank for scientific journals based on the citations of patents, so the percentage of articles cited in patents with Field-Weighted Citation Impact (FWCI) >1, and as an indicator of scientific transfer from universities or research centres, the transference index in patents (TIP) is also proposed.