In search of phylogenetic congruence between molecular and morphological data in bryozoans with extreme adult skeletal heteromorphy

peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=tsab20© Crown Copyright 2015. This document is the author's final accepted/submitted version of the journal article. You are advised to consult the publisher's version if you wish to cite from it

Origin of Life

The evolution of life has been a big enigma despite rapid advancements in the fields of biochemistry, astrobiology, and astrophysics in recent years. The answer to this puzzle has been as mind-boggling as the riddle relating to evolution of Universe itself. Despite the fact that panspermia has gained considerable support as a viable explanation for origin of life on the Earth and elsewhere in the Universe, the issue remains far from a tangible solution. This paper examines the various prevailing hypotheses regarding origin of life like abiogenesis, RNA World, Iron-sulphur World, and panspermia; and concludes that delivery of life-bearing organic molecules by the comets in the early epoch of the Earth alone possibly was not responsible for kick-starting the process of evolution of life on our planet.Comment: 32 pages, 8 figures,invited review article, minor additio

Panspermia, Past and Present: Astrophysical and Biophysical Conditions for the Dissemination of Life in Space

Astronomically, there are viable mechanisms for distributing organic material throughout the Milky Way. Biologically, the destructive effects of ultraviolet light and cosmic rays means that the majority of organisms arrive broken and dead on a new world. The likelihood of conventional forms of panspermia must therefore be considered low. However, the information content of dam-aged biological molecules might serve to seed new life (necropanspermia).Comment: Accepted for publication in Space Science Review

Épocas de dessecação nos atributos pós-colheita de grãos de soja.

Resumo: Visando aumentar a janela de plantio da segunda safra, a aplicação de herbicida dessecante na lavoura de soja antes da maturação fisiológica dos grãos tem sido prática comum no médio norte de Mato Grosso, por parte dos produtores. Assim, objetivou-se, por meio deste trabalho, avaliar o efeito da aplicação de dessecante em diferentes estádios fenológicos da lavoura de soja nos aspectos físicos e químicos dos grãos, em Sinop-MT, durante a safra da soja 2018/19. As cultivares BRS 7980 e M 8372 IPRO foram dessecadas em cinco estádios fenológicos distintos (R5.5, R6, R7.1, R7.3, R8.1). Após a colheita, os grãos foram secos, limpos e classificados. Em seguida, determinou-se a massa específica aparente, a massa de mil grãos e os componentes de composição centesimal (fibra bruta, extrato etéreo, proteína, cinzas, carboidrato e água). A antecipação da dessecação reduziu a massa de mil grãos, aumentou a massa específica aparente e diminuiu a quantidade de óleo nos grãos. A aplicação do herbicida dessecante no estádio recomendado reduziu as injúrias causadas por patógenos nos grãos de soja das duas cultivares. | Abstract: In order to increase the planting window of the second crop, some producers have used an application of desiccant herbicide before physiological maturation of soybeans in the middle northern of Mato Grosso. The objective of this work was to evaluate the effect of desiccant application at different stages of maturation of soybean crops, and to evaluate the influence of this operation on physical and chemical aspects of the grains. We used grains from cultivars BRS 7980 and M 8372 IPRO. For each cultivar evaluated, desiccation occurred in five phenological stages (R5.5, R6, R7.1, R7.3, R8.1). After harvesting, the beans were dried, cleaned and classified. The anticipation of desiccation reduced the mass of a thousand grains, increased the apparent specific mass and decreased the amount of oil in the grains. The application of the desiccant herbicide at the recommended stage reduced the deterioration of the grains in the field, caused by pathogens

Habitable Zones in the Universe

Habitability varies dramatically with location and time in the universe. This was recognized centuries ago, but it was only in the last few decades that astronomers began to systematize the study of habitability. The introduction of the concept of the habitable zone was key to progress in this area. The habitable zone concept was first applied to the space around a star, now called the Circumstellar Habitable Zone. Recently, other, vastly broader, habitable zones have been proposed. We review the historical development of the concept of habitable zones and the present state of the research. We also suggest ways to make progress on each of the habitable zones and to unify them into a single concept encompassing the entire universe.Comment: 71 pages, 3 figures, 1 table; to be published in Origins of Life and Evolution of Biospheres; table slightly revise

The origin of multicellularity in cyanobacteria

Background: Cyanobacteria are one of the oldest and morphologically most diverse prokaryotic phyla on our planet. The early development of an oxygen-containing atmosphere approximately 2.45 - 2.22 billion years ago is attributed to the photosynthetic activity of cyanobacteria. Furthermore, they are one of the few prokaryotic phyla where multicellularity has evolved. Understanding when and how multicellularity evolved in these ancient organisms would provide fundamental information on the early history of life and further our knowledge of complex life forms. Results: We conducted and compared phylogenetic analyses of 16S rDNA sequences from a large sample of taxa representing the morphological and genetic diversity of cyanobacteria. We reconstructed ancestral character states on 10,000 phylogenetic trees. The results suggest that the majority of extant cyanobacteria descend from multicellular ancestors. Reversals to unicellularity occurred at least 5 times. Multicellularity was established again at least once within a single-celled clade. Comparison to the fossil record supports an early origin of multicellularity, possibly as early as the “Great Oxygenation Event” that occurred 2.45 - 2.22 billion years ago. Conclusions: The results indicate that a multicellular morphotype evolved early in the cyanobacterial lineage and was regained at least once after a previous loss. Most of the morphological diversity exhibited in cyanobacteria today —including the majority of single-celled species— arose from ancient multicellular lineages. Multicellularity could have conferred a considerable advantage for exploring new niches and hence facilitated the diversification of new lineages

Management of Ocular Manifestations of Atopic Dermatitis : A Consensus Meeting Using a Modified Delphi Process

There is a need for unified guidance on the management of ocular manifestations of atopic dermatitis and ocular manifestations associated with dupilumab in the Nordic region (Denmark, Finland, Norway and Sweden). This initiative gathered Nordic dermatologists and ophthalmologists to identify consensus in this area using a modified Delphi process. The initiative was led by a Nordic expert panel who developed a questionnaire that was circulated to a wider group. The results informed an agenda consisting of 24 statements to be voted on using a 5-point Likert scale at a meeting in Copenhagen on 24 April 2019. A facilitator moderated discussion and revised statements according to expert feedback for a second vote when required to reach consensus. Consensus was reached for 23 statements regarding the diagnosis, treatment and referral of these patients, which we hope will improve patient management in the Nordic region.Peer reviewe

The Kondo Effect in Non-Equilibrium Quantum Dots: Perturbative Renormalization Group

While the properties of the Kondo model in equilibrium are very well understood, much less is known for Kondo systems out of equilibrium. We study the properties of a quantum dot in the Kondo regime, when a large bias voltage V and/or a large magnetic field B is applied. Using the perturbative renormalization group generalized to stationary nonequilibrium situations, we calculate renormalized couplings, keeping their important energy dependence. We show that in a magnetic field the spin occupation of the quantum dot is non-thermal, being controlled by V and B in a complex way to be calculated by solving a quantum Boltzmann equation. We find that the well-known suppression of the Kondo effect at finite V>>T_K (Kondo temperature) is caused by inelastic dephasing processes induced by the current through the dot. We calculate the corresponding decoherence rate, which serves to cut off the RG flow usually well inside the perturbative regime (with possible exceptions). As a consequence, the differential conductance, the local magnetization, the spin relaxation rates and the local spectral function may be calculated for large V,B >> T_K in a controlled way.Comment: 9 pages, invited paper for a special edition of JPSJ "Kondo Effect -- 40 Years after the Discovery", some typos correcte

Joint transmitter selection and resource management strategy based on low probability of intercept optimization for distributed radar networks

In this paper, a joint transmitter selection and resource management (JTSRM) strategy based on low probability of intercept (LPI) is proposed for target tracking in distributed radar network system. The basis of the JTSRM strategy is to utilize the optimization technique to control transmitting resources of radar networks in order to improve the LPI performance, while guaranteeing a specified target tracking accuracy. The weighted intercept probability and transmit power of radar networks is defined and subsequently employed as the optimization criterion for the JTSRM strategy. The resulting optimization problem is to minimize the LPI performance criterion of radar networks by optimizing the revisit interval, dwell time, transmitter selection, and transmit power subject to a desired target tracking performance and some resource constraints. An efficient and fast three‐step solution technique is also developed to solve this problem. The presented mechanism implements the optimal working parameters based on the feedback information in the tracking recursion cycle in order to improve the LPI performance for radar networks. Numerical simulations are provided to verify the superior performance of the proposed JTSRM strategy