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Summary of a Life in Observational Ultraviolet/Optical Astronomy

Research in Astronomy and Astrophysics 2024年第1期24卷 1-43页

作者： Donald g.York Department of Astronomy and Astrophysics The University of Chicago5801 South Ellis Ave.Chicago 60637ILUSA

I reminisce on my early life in Section 1;on my education in Sections 2 and 3;on the years at princeton as a research astronomer in Section 4;on the years on the faculty at Chicago in Section 5;on research on Diffuse Interstellar Bands(DIBs) in Section 6;on construction of the 3.5 m telescope at Apache point Observatory(ApO)in Section 7;on work on the Sloan Digital Sky Survey(SDSS) in Section 8;on work in public education in Chicago in Section 9;and on my travels in Section 10. My main science research is of an observational nature,concerning galactic and intergalactic interstellar gas. Highlights for me included my work on the orbiting telescope Copernicus, including the discovery of interstellar deuterium;early observations of absorption associated with fivetimes ionized oxygen;and discoveries concerning the phases of gas in the local interstellar medium, based on previously unobservable interstellar UV spectral lines. With other instruments and collaborations, I extended interstellar UV studies to the intergalactic cool gas using quasi-stellar object QSO absorption lines redshifted to the optical part of the spectrum;provided a better definition of the emission and morphological character of the source of absorption lines in QSO spectra;and pursued the identification of the unidentified DIBs. For several of these topics, extensive collaborations with many scientists were essential over many years. The conclusions developed slowly, as I moved from being a graduate student at Chicago, to a research scientist position at princeton and then to a faculty position at Chicago. At each stage of life, I was exposed to new technologies adaptable to my science and to subsequent projects. From high school days, I encountered several management opportunities which were formative. I have been extremely fortunate both in scientific mentors I had and in experimental opportunities I encountered.

关键词： Interstellar Medium(ISM) Nebulae (galaxies:)quasars:absorption lines ultraviolet:stars

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From the dust:extracellular vesicles as regulators of development and neuroregeneration

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Neural Regeneration Research 2024年第5期19卷 933-934页

作者： Leon g.Coleman Jr The University of North Carolina at Chapel Hill School of MedicineDepartment of PharmacologyBowles Center for Alcohol StudiesChapel HillNCUSA

First impressions can have a lasting *** science,this can be especially problematic,because our lack of understanding often causes us to mislabel and thus ignore important biological *** this vein,extracellular vesicles(EVs)were once considered to be“cellular dust”.Similar to the previous concept of“junk DNA”to describe protein non-coding regions,EVs are far more than just cellular *** fact,EVs are emerging as key mediators of intracellular communication across nearly all biological *** includes peripheral immune responses(e.g.,arthropathies and sepsis),intra-organ communication(Seim et al.,2023),and a host of other physiological and pathological states(Figure 1A and B).

关键词： Figure extracellular

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CL2ES-KDBC:A Novel Covariance Embedded Selection Based on Kernel Distributed Bayes Classifier for Detection of Cyber-Attacks in IoT Systems

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Computers, Materials & Continua 2024年第3期78卷 3511-3528页

作者： Talal Albalawi p.ganeshkumar Computer Science Department College of Computer and Information SciencesImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh11432Saudi Arabia

The Internet of Things(IoT)is a growing technology that allows the sharing of data with other devices across wireless ***,IoT systems are vulnerable to cyberattacks due to its opennes The proposed work intends to implement a new security framework for detecting the most specific and harmful intrusions in IoT *** this framework,a Covariance Linear Learning Embedding Selection(CL2ES)methodology is used at first to extract the features highly associated with the IoT ***,the Kernel Distributed Bayes Classifier(KDBC)is created to forecast attacks based on the probability distribution value *** addition,a unique Mongolian gazellas Optimization(MgO)algorithm is used to optimize the weight value for the learning of the *** effectiveness of the proposed CL2ES-KDBC framework has been assessed using several IoT cyber-attack datasets,The obtained results are then compared with current classification methods regarding accuracy(97%),precision(96.5%),and other *** analysis of the CL2ES-KDBC system on IoT intrusion datasets is performed,which provides valuable insight into its performance,efficiency,and suitability for securing IoT networks.

关键词： IoT security attack detection covariance linear learning embedding selection kernel distributed bayes classifier mongolian gazellas optimization

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presynaptic endoplasmic reticulum architecture and hereditary spastic paraplegia

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Neural Regeneration Research 2024年第3期19卷 485-486页

作者： Juan Josépérez-Moreno Instituto de Biomedicina de Sevilla(IBiS) Hospital Universitario Virgen Del Rocío/CSIC/Universidad de Sevillaand Departamento de Biología CelularFacultad de BiologíaUniversidad de SevillaSevilleSpain

Hereditary spastic paraplegia(HSp)is a clinically and genetically heterogeneous neurodegenerative disorder,characterized primarily by progressive spasticity and weakness in the lower *** ients can also experience peripheral neuropathy,cognitive impairment,and other neurological *** date,more than 80 genes have been implicated in HSp,encompassing various cellular components,although mutations in genes encoding endoplasmic reticulum(ER)-shaping proteins are the most prevalent(parodi et al.,2017).ER-shaping proteins are generally known for regulating the tubulation and curvation of the ER,but most of them show additional functions,including fusion of ER tubules,microtubule-severing,ER autophagy,lipid droplet synthesis,contact sites with other organelles(Öztürk et al.,2020).This highlights the complexity of studying the role of these proteins and the link between ER function and HSp.

关键词： reticulum endoplasmic

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Interpreting siliciclastic sedimentation in the upper paleozoic Mulargia-Escalaplano Basin(Sardinia, Italy):influence of tectonics on provenance

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Journal of palaeogeography 2024年第1期13卷 18-34页

作者： Luca g.Costamagna Sara Criniti Dipartimento di Scienze Chimiche e geologiche Citadella UniversitariaBlocco A09042 Monserrato CAItaly Dipartimento di Ingegneria dell'Ambiente Universita della Calabria87036 Arcavacata di Rende CSItaly

Late to post-Variscan molassic basins of Late pennsylvanian-permian age are exposed in Sardinia(Italy). Here, the compositional and stratigraphic evolution of the Mulargia-Escalaplano sedimentary basin(central Sardinia) has been investigated to highlight how the tectono-magmatic processes have influenced the sedimentation. Ruditic and arenitic samples were collected along well-characterized stratigraphic sections to provide a new insight into the impact of the tectono-magmatic processes on siliciclastic sedimentation. As a result, the conglomerates are mainly clast-supported, petromictic, and thus immature, with no defined maturity trend upwards. Nevertheless, pebble composition changes in times from Variscan basement pebble-rich to volcanic rock-rich, as a consequence of the basin widening and the dismantling and reworking of the coeval volcanic activity. The sandstone composition clearly changes from quartzolithic to feldspatholithic upwards, as a response to the same change of feeding and reworking of the volcanic rocks. Occasionally, interbedded quartzolithic arenites suggest exceptional floods carrying debris from the far borders of the basin. Also, the immature sandstone composition has been interpreted as being controlled by a continuous supply of fresh debris and to a rapid burial rate. In addition, the disappearance of metaradiolarite(lydite AA) paleozoic grains in the sandstone mineral suite could represent a distinctive marker of a progressive unroofing of the Variscan chain and a clastic supply from deeper tectonic units.

关键词： petrography Stratigraphy provenance Molassic basins Sardinia

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Endotoxin-induced alterations of adipose tissue function:a pathway to bovine metabolic stress

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Journal of Animal Science and Biotechnology 2024年第4期15卷 1391-1407页

作者： Miguel Chirivi g.Andres Contreras Department of Large Animal Clinical Sciences Michigan State UniversityEast LansingMIUSA

During the periparturient period, dairy cows exhibit negative energy balance due to limited appetite and increased energy requirements for lactogenesis. The delicate equilibrium between energy availability and expenditure puts cows in a state of metabolic stress characterized by excessive lipolysis in white adipose tissues(AT), increased production of reactive oxygen species, and immune cell dysfunction. Metabolic stress, especially in AT, increases the risk for metabolic and inflammatory diseases. Around parturition, cows are also susceptible to endotoxemia. Bacterial-derived toxins cause endotoxemia by promoting inflammatory processes and immune cell infiltration in different organs and systems while impacting metabolic function by altering lipolysis, mitochondrial activity, and insulin sensitivity. In dairy cows, endotoxins enter the bloodstream after overcoming the defense mechanisms of the epithelial barriers, particularly during common periparturient conditions such as mastitis, metritis, and pneumonia, or after abrupt changes in the gut microbiome. In the bovine AT, endotoxins induce a pro-inflammatory response and stimulate lipolysis in AT, leading to the release of free fatty acids into the bloodstream. When excessive and protracted, endotoxin-induced lipolysis can impair adipocyte's insulin signaling pathways and lipid synthesis. Endotoxin exposure can also induce oxidative stress in AT through the production of reactive oxygen species by inflammatory cells and other cellular components. This review provides insights into endotoxins' impact on AT function, highlighting the gaps in our knowledge of the mechanisms underlying AT dysfunction, its connection with periparturient cows' disease risk, and the need to develop effective interventions to prevent and treat endotoxemia-related inflammatory conditions in dairy cattle.

关键词： Adipose tissue dysfunction Endotoxin Inflammation Insulin resistance

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Direct-to-indirect mapping for optimal low-thrust trajectories

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Astrodynamics 2024年第1期8卷 27-46页

作者： David Ottesen Ryan p.Russell Department of Aerospace Engineering and Engineering Mechanics The University of Texas at AustinAustinTexas78712USA

Optimal,many-revolution spacecraft trajectories are challenging to solve.A connection is made for a class of models between optimal direct and indirect *** transfers that minimize thrust-acceleration-squared,primer vector theory maps direct,many-impulsive-maneuver trajectories to the indirect,continuous-thrust-acceleration *** mapping algorithm is independent of how the direct solution is obtained and requires only a solver for a boundary value problem and its partial derivatives.A Lambert solver is used for the two-body problem in this *** mapping is simple because the impulsive maneuvers and co-states share the same linear space around an optimal *** numerical results,the direct coast-impulse solutions are demonstrated to converge to the indirect continuous solutions as the number of impulses and segments *** two-body design space is explored with a set of three many-revolution,many-segment examples changing semimajor axis,eccentricity,and *** first two examples involve a small change to either semimajor axis or eccentricity,and the third example is a transfer to geosynchronous *** a single processor,the optimization runtime is seconds to minutes for revolution counts of 10 to 100,and on the order of one hour for examples with up to 500 *** of these thrust-acceleration-squared solutions are good candidates to start a homotopy to a higher-fidelity minimization problem with practical constraints.

关键词： direct optimization indirect optimization impulsive maneuvers Lambert's problem two-body dynamics primer vectortheory

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palladium-catalyzed S_(N)2 glycosylation of phenols

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Science China Chemistry 2024年第4期67卷 1037-1038页

作者： Yu Zhu p.Andrew Evans Department of Chemistry Queen’s University90 Bader LaneKingstonK7L 3N6Canada Xiangya School of pharmaceutical Sciences Central South UniversityChangsha 410013China

glycosides are essential structural motifs present in an array of important medicines,materials,and natural products[1].Nevertheless,the chemo-and stereoselective construction of the glycosidic linkage is a long-standing challenge because relatively minor variations in the glycosyl donor or acceptor’s structure can impact stereoselectivity,thus influencing the product's functional properties.

关键词： properties palladium catalyzed

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Empirical Wavelet Transform Based Method for Identification and Analysis of Sub-synchronous Oscillation Modes Using pMU Data

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Journal of Modern power Systems and Clean Energy 2024年第1期12卷 34-40页

作者： Joice g.philip Jaesung Jung Ahmet Onen the Department of Energy Systems Research Ajou UniversitySuwonSouth Korea the Department of Electrical and Electronic Engineering Abdullah Gul UniversityKayseri38080Turkey the Department of Electrical and Computer Engineering College of EngineeringSultan Qaboos UniversityAl-KhoudMuscatOman

This paper proposes an empirical wavelet transform(EWT)based method for identification and analysis of sub-synchronous oscillation(SSO)modes in the power system using phasor measurement unit(pMU)*** phasors from pMUs are preprocessed to check for the presence of *** the presence is established,the signal is decomposed using EWT and the parameters of the mono-components are estimated through Yoshida *** superiority of the proposed method is tested using test signals with known parameters and simulated using actual SSO signals from the Hami power grid in Northwest *** show the effectiveness of the proposed EWT-Yoshida method in detecting the SSO and estimating its parameters.

关键词： Empirical wavelet transform(EWT) sub-synchronous oscillation prony-based method Yoshida algorithm variational mode decomposition phasor measurement unit(pMU)

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Specificity of electrophysical and gas-sensitive properties of nanocomposite ZnO–TiO_(2) films formed by solid-phase pyrolysis

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ChemphysMater 2024年第3期3卷 314-319页

作者： Victor V.petrov Maria g.Volkova Alexsandra p.Ivanishcheva gleb V.Tolstyak Ekaterina M.Bayanb Institute of Nanotechnologies Electronicsand Equipment EngineeringSouthern Federal UniversityTaganrog 347922Russia Faculty of Chemistry Southern Federal UniversityRostov-on-Don 344090Russia

ZnO–TiO_(2) thin films containing 0.5 mol%,1.0 mol%,and 5.0 mol%ZnO were synthesized by oxidative solidphase *** materials contained anatase and rutile phases with particle size of 6–13 nm,as confirmed using X-ray phase analysis and scanning electron *** a certain number of ZnO crystallites appeared in the TiO_(2) film structure in the temperature range of room temperature to 220℃,a two-level response of the film resistance was observed,differing by approximately 10%,as obtained by electrophysical *** two-level response correlates with the formation of two donor energy levels of 0.28 and 0.33 eV in the band structure of the ZnO–TiO_(2) *** donor level with a higher activation energy corresponded to the Ti vacancy(V−Ti),and that with a lower activation energy corresponded to the Zn vacancy(V−Zn).Two levels of gas-sensitive properties were noted for 0.5ZnO–TiO_(2),1ZnO–TiO_(2),and 5ZnO–TiO_(2) under the influence of 50 ppm NO_(2) at 250℃.Such two-level responses can be ascribed to the pinning of the Fermi level on ZnO and TiO_(2) *** mechanism of the beak-shaped and two-level responses of sensors based on composite nanomaterials when exposed to various gases was elucidated.

关键词： Thin film ZnO TiO_(2) Nanocomposites pyrolysis gas sensors

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