ABSTRACT
We present the results of spectroscopic observations of two eclipsing WR + OB-type systems – CQ Cep and CX Cep – performed in 2020–2023 with a low-resolution slit spectrograph TDS (λλ = ...3660–7410 Å, R = 1300–2500) on 2.5-m telescope of the SAI MSU Caucasian Mountain Observatory. For CQ Cep, the radial velocity curves of a WN6 star are constructed, the problem of visibility of spectroscopic traces of an OB star is discussed, and the components’ mass ratio q ∼ 0.6 is estimated. For CX Cep, the radial velocity curves are constructed for both the WN5 and O5 components enabling their masses and circular orbit elements to be refined. The comparison of the radial velocity curves of these systems obtained in different epochs allowed us to derive the orbital period change rate $\dot{P}$ by the spectroscopic method, which is found to be in good agreement with estimates obtained by comparing the moments of primary eclipse minima: $\dot{P} = -0.0151\pm 0.0013$ s yr−1 for CQ Cep and $\dot{P} = 0.054\pm 0.009$ s yr−1 for CX Cep. The prospects of applicability of the spectroscopic dynamical method for studying the orbital evolution of Galactic WR + OB binaries and related objects are considered. We also discuss the effect of finite sizes of stars with stellar wind mass-loss in close binary systems on their orbital evolution.
AH Cep and CW Cep are both early B-type binaries with short orbital periods of 1.8 days and 2.7 days, respectively. All four components are B0.5V types. The binaries are also double-lined ...spectroscopic and eclipsing. Consequently, solutions for orbital and stellar parameters make the pair of binaries ideal targets for a study of the colliding winds between two B stars. Chandra ACIS-I observations were obtained to determine X-ray luminosities. AH Cep was detected with an unabsorbed X-ray luminosity at a 90% confidence interval of erg s−1, or , relative to the combined Bolometric luminosities of the two components. While formally consistent with expectations for embedded wind shocks, or binary wind collision, the near-twin system of CW Cep was a surprising nondetection. For CW Cep, an upper limit was determined with , again for the combined components. One difference between these two systems is that AH Cep is part of a multiple system. The X-rays from AH Cep may not arise from standard wind shocks nor wind collision, but perhaps instead from magnetism in any one of the four components of the system. The possibility could be tested by searching for cyclic X-ray variability in AH Cep on the short orbital period of the inner B stars.
Com base nas legislações recentes e vigentes em âmbito nacional (Resolução nº 510/2016 e Resolução nº 674/2022, do Conselho Nacional de Saúde) e local e em discussões de autores contemporâneos que ...têm debatido o tema da ética em pesquisas na área da Educação, considera-se pertinente a discussão a respeito das limitações do Comitê de Ética em Pesquisa/Comissão Nacional de Ética em Pesquisa (CEP/Conep) acessado por meio da base Plataforma Brasil (sistema eletrônico unificado de registro de pesquisas envolvendo seres humanos, vinculado ao Ministério da Saúde) no que diz respeito às especificidades das pesquisas em Ciências Humanas e Sociais (CHS). A hipertrofia de exigências no processo de solicitação de aprovação do CEP via Plataforma Brasil e as burocracias (formulários extensos e generalizados) que não condizem com as especificidades das pesquisas em CHS revelam a importância de uma readequação do procedimento adotado, sob a óptica da educação, que conceba a ética para além de um conjunto de normas e preenchimento de formulários.
The ubiquitin-proteasome system (UPS) and ubiquitin-like protein (UBL) conjugation pathways are integral to cellular protein homeostasis. The growing recognition of the fundamental importance of ...these pathways to normal cell function and in disease has prompted an in-depth search for small-molecule inhibitors that selectively block the function of these pathways. However, our limited understanding of the molecular mechanisms and biological consequences of UBL conjugation is a significant hurdle to identifying drug-like inhibitors of enzyme targets within these pathways. Here, we highlight recent advances in understanding the role of some of these enzymes and how these new insights may be the key to developing novel therapeutics for diseases including immuno-inflammatory disorders, cancer, infectious diseases, cardiovascular disease and neurodegenerative disorders.
Root system architecture (RSA) influences the acquisition of heterogeneously dispersed soil nutrients. Cytokinin and C-TERMINALLY ENCODED PEPTIDE (CEP) hormones affect RSA, in part by controlling the ...angle of lateral root (LR) growth. Both hormone pathways converge on CEP DOWNSTREAM 1 (CEPD1) and CEPD2 to control primary root growth; however, a role for CEPDs in controlling the growth angle of LRs is unknown. Using phenotyping combined with genetic and grafting approaches, we show that CEP hormone-mediated shallower LR growth requires cytokinin biosynthesis and perception in roots via ARABIDOPSIS HISTIDINE KINASE 2 (AHK2) and AHK3. Consistently, cytokinin biosynthesis and ahk2,3 mutants phenocopied the steeper root phenotype of cep receptor 1 (cepr1) mutants on agar plates, and CEPR1 was required for trans-Zeatin (tZ)-type cytokinin-mediated shallower LR growth. In addition, the cepd1,2 mutant was less sensitive to CEP and tZ, and showed basally steeper LRs on agar plates. Cytokinin and CEP pathway mutants were grown in rhizoboxes to define the role of these pathways in controlling RSA. Only cytokinin receptor mutants and cepd1,2 partially phenocopied the steeper-rooted phenotype of cepr1 mutants. These results show that CEP and cytokinin signaling intersect to promote shallower LR growth, but additional components contribute to the cepr1 phenotype in soil.
With the implementation of China’s national carbon trading market, concerns arose over how many gross domestic product (GDP) losses caused by carbon reduction could be recovered by trading carbon ...emissions. Accordingly, we proposed a new linear programming-based three-step estimation approach to systematically investigate four critical issues in carbon emissions trading. These are how to initially allocate carbon trading permits, set the carbon trading price, determine the amount of GDP loss recoveries that could be obtained from carbon trading, and how setting emission reduction targets. Our empirical results showed the following: (I) The allocation modes based on the sovereignty criterion and the ability-to-pay criterion resulted in the lowest (2.84%) and highest (24.56%) concussion impacts on GDP, respectively. (II) The optimal range of the carbon trading price was linked closely to the carbon emission reduction target. Specifically, when the reduction target was set at 10%, the estimated optimal carbon trading price was 256.2–394.8 Yuan/ton, which is higher than the price used in the carbon trading pilot market. (III) If the emission reduction target were set at more than 10%, China could recover at least 598.62 G Yuan of economic losses through the carbon trading market. (IV) From an economic perspective, the single allocation mode, the sovereignty-criterion-based allocation mode, was superior to the mixed allocation modes. We provide several suggestions for policymakers to implementing a carbon emissions trading market in China.
•Trading carbon emissions could recoup GDP losses caused by carbon reductions.•Carbon emissions trading critical issues investigated employing new approach.•Linear programming-based three-step estimation approach proposed.
The paper deals with twenty-two species and subspecies of tiger beetles of the Palaearctic Region, except the species of Romanian fauna. The specimens preserved in the collections of “Grigore ...Antipa” National Museum of Natural History, Bucharest has been reviewed.
The Internet of Things (IoT) has grown rapidly to become the core of many areas of application, leading to the integration of sensors, with IoT devices. However, the number of attacks against these ...types of devices has grown as fast as the paradigm itself. Certain inherent characteristics of the paradigm, as well as the limited computational capabilities of the devices involved, make it difficult to deploy security measures. This is why it is necessary to design, implement and study new solutions in the field of cybersecurity. In this paper, we propose an architecture that is capable of generating Complex Event Processing (CEP) rules automatically by integrating them with machine learning technologies. While the former is used to automatically detect attack patterns in real time, the latter, through the use of the Principal Component Analysis (PCA) algorithm, allows the characterization of events and the recognition of anomalies. This combination makes it possible to achieve efficient CEP rules at the computational level, with the results showing that the CEP rules obtained using our approach substantially improve upon the performance of the standard CEP rules, which are rules that are not generated by our proposal but can be defined independently by an expert in the field. Our proposal has achieved an F1-score of 0.98 on average, a 76 percent improvement in throughput over standard CEP rules, and a reduction in the network overhead of 86 percent over standard simple events, which are the simple events that are generated when our proposal is not used.
We present a study of the kinematics and structure of the Cep OB3b cluster based on new spectra obtained with the Hectoschelle spectrograph on the MMT and data from Spitzer, Chandra, and Gaia. At a ...distance of 819 16 pc, Cep OB3b is one of the closest examples of a young (∼3-5 Myr), large (∼3000 total members) cluster at the late stages of gas dispersal. The cluster is broken into two subclusters surrounded by a lower density halo. We fit the empirical density law of King to each subcluster to constrain their sizes and structure. The richer eastern subcluster has circular symmetry, a modest central density, and lacks molecular gas toward its core, suggesting it has undergone expansion due to gas dispersal. In contrast, the western subcluster deviates from circular symmetry, has a smaller core size, and contains significant molecular gas near its core, suggesting that it is in an earlier phase of gas dispersal. We present posterior probability distributions for the velocity dispersions from the Hectoschelle spectra. The east will continue to expand and likely form a bound cluster with ∼35% of stars remaining. The west is undergoing slower gas dispersal and will potentially form a bound cluster with ∼75% of stars remaining. If the halo dissipates, this will leave two independent clusters with ∼300 members; proper motions suggest that the two subcluster are not bound to each other.
The pectin (CEP) was used as matrix material to prepare Ag@AgCl/ZnO nanocomposites with a green method for photocatalytic antibacterial activity in visible-light. Briefly, Ag@AgCl plasmonic hybrids ...were prepared in the CEP macromolecule matrix with size control, which was attributed to the stability of carboxyl and hydroxyl groups on the CEP. Subsequently, an effective and green two-steps approach was explored for the fabrication of CEP-Ag@AgCl/ZnO nanocomposites with resource saving and environment friendly. Interestingly, more Ag+ was converted into metallic Ag in the CEP-Ag@AgCl/ZnO than that in the CEP-Ag@AgCl. This phenomenon was attributed that the reducibility of free hemiacetal hydroxyl groups on CEP was realized with the help of NaOH in the preparation of CEP-ZnO. In addition, the CEP chains were not obviously destroyed except for the change in the crystallinity after the preparation of the CEP-Ag@AgCl/ZnO nanocomposites, indicating that the method was non-destructive. Moreover, the pH triggered release of Zn2+ and low release of Ag+ in CEP-Ag@AgCl/ZnO nanocomposites with excellent photocatalytic antibacterial activity were confirmed in this work. The proposed green process provides a new idea for the large-scale production of antibacterial pectin-based nanocomposites in industry with a low-cost.
•Application of pectin from Akebia trifoliata var. australis waste was broadened.•CEP-Ag@AgCl plasmonic hybrids were prepared with non-destructive of CEP.•A green two-steps process was proposed to prepare the CEP-Ag@AgCl/ZnO.•CEP-Ag@AgCl/ZnO exhibit pH triggered release of Zn2+ with low Ag+ loss.•CEP-Ag@AgCl/ZnO exhibit photocatalytic antibacterial activity in visible-light.
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