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Copyright of Álabe is the property of Alabe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of OCNOS: Journal of Reading Research / Revista de Estudios sobre Lectura is the property of Universidad de Castilla-La Mancha, Facultad de Ciencias de la Educacion y Humanidades and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The synthesis and characterization of (tBuPBP)Ni(OAc) (5) by insertion of carbon dioxide into the Ni−C bond of (tBuPBP)NiMe (1) is presented. An unexpected CO2 cleavage process involving the formation of new B−O and Ni−CO bonds leads to the generation of a butterfly‐structured tetra‐nickel cluster (tBuPBOP)2Ni4(μ‐CO)2 (6). Mechanistic investigation of this reaction indicates a reductive scission of CO2 by O‐atom transfer to the boron atom via a cooperative nickel‐boron mechanism. The CO2 activation reaction produces a three‐coordinate (tBuP2BO)Ni‐acyl intermediate (A) that leads to a (tBuP2BO)−NiI complex (B) via a likely radical pathway. The NiI species is trapped by treatment with the radical trap (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO) to give (tBuP2BO)NiII(η2‐TEMPO) (7). Additionally, 13C and 1H NMR spectroscopy analysis using 13C‐enriched CO2 provides information about the species involved in the CO2 activation process. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of (tBuPBP)Ni(OAc) (5) by insertion of carbon dioxide into the Ni−C bond of (tBuPBP)NiMe (1) is presented. An unexpected CO2 cleavage process involving the formation of new B−O and Ni−CO bonds leads to the generation of a butterfly‐structured tetra‐nickel cluster (tBuPBOP)2Ni4(μ‐CO)2 (6). Mechanistic investigation of this reaction indicates a reductive scission of CO2 by O‐atom transfer to the boron atom via a cooperative nickel‐boron mechanism. The CO2 activation reaction produces a three‐coordinate (tBuP2BO)Ni‐acyl intermediate (A) that leads to a (tBuP2BO)−NiI complex (B) via a likely radical pathway. The NiI species is trapped by treatment with the radical trap (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO) to give (tBuP2BO)NiII(η2‐TEMPO) (7). Additionally, 13C and 1H NMR spectroscopy analysis using 13C‐enriched CO2 provides information about the species involved in the CO2 activation process. [ABSTRACT FROM AUTHOR]

Copyright of RIED: Revista Iberoamericana de Educación a Distancia is the property of Revista Iberoamericana de Educacion a Distancia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The metaverse is presented as a possible new technological iteration for the Internet. The generation of virtual universes in which the physical and the digital converge raises the question of how education will be addressed in these new systems. We find, however, pioneering exercises such as Minecraft: Education Edition. This platform is a version based on the popular sandbox video game, which was originally created by a community of teachers. The aim of this research is to analyze and describe the idiosyncratic characteristics of Minecraft as an educational platform, framing it as one of the pioneering exercises in the metaverse. To this end, we have employed a methodology that combines Multimodal Discourse Analysis with Grounded Theory and the Constant Comparative Method. As conclusions, we observe how the Minecraft Education platform reinforces from its approach pre-existing aspects from the physical world, resizing them to adapt them to its connected digital environment. These are key elements such as the identity of the participants, their ability to act within the system, creativity through lessons as a guide to the educational objectives and the community as the backbone of the process. At the same time, it presents differential components, such as the use of avatars, the transition from textual literacy to multimodal literacy, game mechanics that boost creativity or transhuman capabilities that defy physical space-time. All in all, the platform is designed for teachers, parents and managers, to whom it offers a series of benefits. Therefore, the pedagogical action will depend on their judgment and execution, especially through the elaboration of lessons and worlds, the management of the sessions and their interaction in community environments. It is their responsibility to ensure that the educational experience is truly empowering or, on the contrary, that it ends up being governed by reproductive criteria linked to symbolic violence. [ABSTRACT FROM AUTHOR]

Copyright of Icono 14 is the property of Grupo Icono 14 and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The efficient catalytic hydrosilylation of ketones and aldehydes has been investigated using a nickel pincer hydride complex supported by a diphosphino‐boryl ligand (PBP). It was found that the presence of the boryl group within the skeleton of the ligand has a beneficial effect on the catalytic activities observed for ketones compared to related pincer systems. The analysis of the reaction mechanism allows for the synthesis and characterization of a nickel alkoxide derivative by insertion of the carbonyl moiety into the Ni−H bond. Combined experimental and theoretical analysis (DFT) support a reaction mechanism that involves the initial formation of an alkoxide complex followed by reaction with the silane to release the corresponding silyl ether and regenerate the catalyst. [ABSTRACT FROM AUTHOR]

Copyright of Veritas: Journal of Philosophy & Theology is the property of Saint Rafael Pontifical Major Seminary and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Icono 14 is the property of Grupo Icono 14 and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Platinum complexes have been often considered as the least reactive of the group 10 triad metals. Slow kinetics are behind this lack of reactivity but, still, some industrially relevant catalytic process are dominated by platinum compounds and sometimes different selectivities can be found in comparison to Ni or Pd. Nevertheless, during the last years, it has been reported that the catalytic behaviour of well-defined platinum derivatives can be improved through a judicious choice of their electronic and steric properties, leading to highly electrophilic or low-electron count platinum systems. In this feature article, we highlight some catalytic processes in which well-defined electrophilic platinum complexes or coordinatively unsaturated systems play an important role in their catalytic activity. [ABSTRACT FROM AUTHOR]

There are few studies devoted to analyze the relationships between the structure of the social network and performance in the online learning process as group. In this study, the Community of Inquiry (CoI) model is used as an analytical framework, along with quantitative content analysis and social network analysis, in order to identify the effect of density, centralization, and centrality—of the coordinators—in the different categories of CoI model in self-regulated groups, according to the type of task. Over a period of 3 academic years, a total of 96 discussion forums and 7,155 units of analysis were analyzed, focusing on two types of tasks. The results showed that the effects of the density, centralization, and centrality of the coordinators on the categories of social and cognitive presence were moderated by the type of task. The findings contribute to identify the adequate structure of the social network for the CoI model categories and the learning tasks. [ABSTRACT FROM AUTHOR]

Education is at a time of redefinition and transformation, in line with an era characterized by considerable technological development and profound social changes. One would expect it to be accompanied by a media context in which narrative models are transformed by the impact of digitalization, affecting student-teacher interactions. However, it has been observed that the media usage of an entire generation emphasizes the gap between formal education and young people's everyday digital life. Within this framework, and at the international level, a series of innovative pedagogical proposals have emerged, which approach education from the field of communication: Minecraft Education, NFB Education, Educ'Arte, Scratch and 7 de Cinema. We have called them com-educational platforms, because of their investment in the education-communication vector, based on an educommunicative idea. The proposed study implements a multimodal discourse analysis (MDA) to gain an in-depth knowledge of its characteristics. Beyond their individual idiosyncrasies, our analysis reveals a common central feature: the placement of community-creativity combination as the core phenomenon for learning. [ABSTRACT FROM AUTHOR]

Copyright of Alteridad: Revista de Educación is the property of Universidad Politecnica Salesiana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of RIED: Revista Iberoamericana de Educación a Distancia is the property of Revista Iberoamericana de Educacion a Distancia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of RAP: Revista Brasileira de Administração Pública is the property of RAP: Revista Brasileira de Administracao Publica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Internacional de Relaciones Públicas is the property of Instituto de Investigacion en Relaciones Publicas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We describe the synthesis and the molecular and electronic structures of the complex [Mo2Me2{μ-HC(NDipp)2}2] ( 2; Dipp=2,6- iPr2C6H3), which contains a dimetallic core with an Mo-Mo quadruple bond and features uncommon four-coordinate geometry and has a fourteen-electron count for each molybdenum atom. The coordination polyhedron approaches a square pyramid, with one of the molybdenum atoms nearly co-planar with the basal square plane, in which the trans coordination position with respect to the Mo−Me bond is vacant. The other three sites are occupied by two trans nitrogen atoms of different amidinate ligands and the methyl group. The second Mo atom occupies the apex of the pyramid and forms an Mo-Mo bond of length 2.080(1) Å, consistent with a quadruple bond. Compound 2 reacts with tetrahydrofuran (THF) and trimethylphosphine to yield the mono-adducts [Mo2Me(μ-Me){μ-HC(NDipp)2}2(L)] ( 3⋅THF and 3⋅PMe3, respectively) with one terminal and one bridging methyl group. In contrast, 4-dimethylaminopyridine (dmap) forms the bis-adduct [Mo2Me2{μ-HC(NDipp)2}2(dmap)2] ( 4), with terminally coordinated methyl groups. Hydrogenolysis of complex 2 leads to the bis(hydride) [Mo2H2{μ-HC(NDipp)2}2(thf)2] ( 5⋅THF) with elimination of CH4. Computational, kinetic, and mechanistic studies, which included the use of D2 and of complex 2 labelled with 13C (99 %) at the Mo-CH3 sites, supported the intermediacy of a methyl-hydride reactive species. A computational DFT analysis of the terminal and bridging coordination of the methyl groups to the Mo≣Mo core is also reported. [ABSTRACT FROM AUTHOR]

The low-electron-count cationic platinum complex [Pt(I tBu')(I tBu)][BArF], 1, interacts with primary and secondary silanes to form the corresponding σ-SiH complexes. According to DFT calculations, the most stable coordination mode is the uncommon η1-SiH. The reaction of 1 with Et2SiH2 leads to the X-ray structurally characterized 14-electron PtII species [Pt(SiEt2H)(I tBu)2][BArF], 2, which is stabilized by an agostic interaction. Complexes 1, 2, and the hydride [Pt(H)(I tBu)2][BArF], 3, catalyze the hydrosilation of CO2, leading to the exclusive formation of the corresponding silyl formates at room temperature. [ABSTRACT FROM AUTHOR]

The selective reduction of CO2 to the formaldehyde level remains an important challenge and to date only a few catalysts have been developed for this reaction. Herein, we report an efficient catalyst that consists of a bis(phosphino)boryl nickel hydride complex in combination with B(C6F5)3, for the highly selective hydrosilation of CO2 to bis(silyl)acetal derivatives. [ABSTRACT FROM AUTHOR]

To clarify the nature of the Mo-Carene interaction in terphenyl complexes with quadruple Mo-Mo bonds, ether adducts of composition [Mo2(Ar')(I)(O2CR)2(OEt2)] have been prepared and characterized (Ar'=ArXyl2, R=Me; Ar'=ArMes2, R=Me; Ar'=ArXyl2, R=CF3) (Mes=mesityl; Xyl=2,6-Me2C6H3, from now on xylyl) and their reactivity toward different neutral Lewis bases investigated. PMe3, P(OMe)3 and PiPr3 were chosen as P-donors and the reactivity studies complemented with the use of the C-donors CNXyl and CN2C2Me4 (1,3,4,5- tetramethylimidazol-2-ylidene). New compounds of general formula [Mo2(Ar')(I)(O2CR)2(L)] were obtained, except for the imidazol-2-ylidene ligand that yielded a salt-like compound of composition [Mo2(ArXyl2)(O2CMe)2(CN2C2Me4)2]I. The Mo- Carene interaction in these complexes has been analyzed with the aid of X-ray data and computational studies. This interaction compensates the coordinative and electronic unsaturation of one of the Mo atoms in the above complexes, but it seems to be weak in terms of sharing of electron density between the Mo and Carene atoms and appears to have no appreciable effect in the length of the Mo-Mo, Mo-X, and Mo-L bonds present in these molecules. [ABSTRACT FROM AUTHOR]

A stable nickel(II) methyl complex containing a diphosphino-boryl (PBP) pincer ligand is described. Mechanistic studies on the hydrogenolysis of the Ni-Me bond suggest a metal ligand cooperation mechanism that involves the intermediacy of a r-B-H Ni(0) species that further undergoes B-H oxidative addition to form a Ni(II) hydride complex. [ABSTRACT FROM AUTHOR]

The bis(hydride) dimolybdenum complex, [Mo2(H)2{HC( N-2,6- iPr2C6H3)2}2(thf)2], 2, which possesses a quadruply bonded Mo2II core, undergoes light-induced (365 nm) reductive elimination of H2 and arene coordination in benzene and toluene solutions, with formation of the MoI2 complexes [Mo2{HC( N-2,6- iPr2C6H3)2}2(arene)], 3⋅C6H6 and 3⋅C6H5Me, respectively. The analogous C6H5OMe, p-C6H4Me2, C6H5F, and p-C6H4F2 derivatives have also been prepared by thermal or photochemical methods, which nevertheless employ different Mo2 complex precursors. X-ray crystallography and solution NMR studies demonstrate that the molecule of the arene bridges the molybdenum atoms of the MoI2 core, coordinating to each in an η2 fashion. In solution, the arene rotates fast on the NMR timescale around the Mo2-arene axis. For the substituted aromatic hydrocarbons, the NMR data are consistent with the existence of a major rotamer in which the metal atoms are coordinated to the more electron-rich CC bonds. [ABSTRACT FROM AUTHOR]

Aus 4 mach 5 (und umgekehrt): UV ‐ Bestrahlung eines Bis(amidinat) ‐ Komplexes mit [(H)MoMo(H)] ‐ Kern induziert die reduktive Eliminierung von H2 unter Bildung einer bekannten Mo ‐ Mo ‐ Spezies mit Fünffachbindung (siehe Schema), die durch Rückreaktion mit H2 wieder [(H)MoMo(H)] bildet. UV ‐ Bestrahlung der Bis(hydrid) ‐ Spezies in Benzol und Toluol ergibt Aren ‐ Komplexe, in denen der aromatische Kohlenwasserstoff die Mo ‐ Atome verbrückt. Dipp=2,6 ‐ Diisopropylphenyl. [ABSTRACT FROM AUTHOR]

Five plus H2 gives four: UV irradiation of a bis(amidinate) complex with a [(H)MoMo(H)] core induces reductive elimination of H2 and formation of a known quintuply bonded MoMo species (see scheme) that reacts back with H2 to restore [(H)MoMo(H)]. UV irradiation of the bis(hydride) species in benzene and toluene gives arene complexes in which the aromatic hydrocarbon bridges the molybdenum atoms. Dipp=2,6‐diisopropylphenyl. [ABSTRACT FROM AUTHOR]

Several composites of a metallocene syndiotactic polypropylene with an organophilic silicate have been prepared and analyzed to investigate the effects of the nanoparticles on the crystallization of syndiotactic polypropylene. Moreover, the influence of an electron‐irradiation dose of 166 kGy on the different materials has been studied. Although the melting temperatures are practically unchanged, irradiation leads to a considerably slower crystallization rate of the syndiotactic polypropylene homopolymer in such a way that an important cold crystallization has been observed in the second melting along with a much higher value of the isothermal crystallization half‐time. On the contrary, the nanocomposites are much less sensitive to irradiation because only a small shift of the crystallization temperature has been observed, and the isothermal crystallization half‐time remains practically unaffected. However, irradiation leads to important changes in the low‐angle region of X‐ray diffractograms. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1068–1076, 2007 [ABSTRACT FROM AUTHOR]

Microbial cooperation pervades ecological scales, from single-species populations to host-associated microbiomes. Understanding the mechanisms promoting the stability of cooperation against potential threats by cheaters is a major question that only recently has been approached experimentally. Synthetic biology has helped to uncover some of these basic mechanisms, which were to some extent anticipated by theoretical predictions. Moreover, synthetic cooperation is a promising lead towards the engineering of novel functions and enhanced productivity of microbial communities. Here, we review recent progress on engineered cooperation in microbial ecosystems. We focus on bottom-up approaches that help to better understand cooperation at the population level, progressively addressing the challenges of tackling higher degrees of complexity: spatial structure, multispecies communities, and host-associated microbiomes. We envisage cooperation as a key ingredient in engineering complex microbial ecosystems. [ABSTRACT FROM AUTHOR]