561975 research outputs found
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Introduction
No full textThe recent rapid growth of interest in theories of the state can be readily explained by the rise in the importance of and controversies surrounding the institution in question in most advanced capitalist societies. It ought therefore to represent a rare and happy example of political sociology responding to a widespread concern in the society at large and in turn enlightening public debate. In fact it is doubtful if anything of the kind has occurred, beyond a rather distorted political debate over corporatism and fears of overloaded government. For a start, those involved in public affairs usually have too many axes of their own to grind to welcome the frequently very different analyses of academic outsiders. But also, much of the academic literature has been highly abstract, virtually metaphysical, especially that from the various Marxist schools which in fact constitutes the bulk of the writing in question
Model-independent determination of nuclear charge radii from Li-like ions
No full textWe demonstrate that recent advances in QED theory of Li-like ions [V. A. Yerokhin, et al., Phys. Rev. A 112, 042801 (2025)] enable determinations of absolute nuclear charge radii for heavy elements. By incorporating constraints derived from electron-scattering data, we obtain radii that are independent of the assumed model of the nuclear charge distribution. Our approach is validated for 208Pb, a well-studied spherical nucleus, and is then applied to 209Bi, where low-lying nuclear excitations complicate the interpretation of muonic-atom data
3D printing of carbon-based scaffolds with aligned structures for anisotropic and high-performance electromagnetic interference shielding
No full textAchieving both free structural integration and efficient electromagnetic compatibility for electronics is a crucial challenge, especially in increasingly complex electromagnetic environments. Herein, a novel construction strategy to fabricate carbon-based functional scaffolds via direct ink writing (DIW) 3D printing technology is demonstrated. The aligned structures are successfully prepared by the use of shear field-driven action and layer-by-layer assembly, thus realizing anisotropic and superior electromagnetic interference (EMI) shielding for materials. The 3D-printed scaffolds with carbon nanotube/graphene (CNT/Gr) aligned structures possess lightweight (∼0.18 g·cm−3) and high-performance EMI shielding (54.6 dB), which corresponds to an extremely low electromagnetic wave transmittance (<0.00001). Moreover, the excellent shielding capability of scaffolds is demonstrated over broad frequency ranges, that the shielding values can reach up to ∼ 49 dB at 2–8 GHz and ∼ 37 dB at 75–110 GHz, respectively. Overall, the developments of this study not only provide a promising paradigm for realizing aligned structural construction via 3D printing shear field, but also serve as a versatile approach to assemble high-performance carbon-based shielding materials for next-generation electronic systems
Genomic and morphometric evidence for Austronesian-mediated pig translocation in the Pacific
No full textSeveral millennia of human-mediated translocation of non-native pig species (genus Sus) to the islands of Wallacea and Oceania have considerably altered local ecosystems. To investigate the timing and trajectory of these introductions, we conducted both genomic analyses of 576 pig nuclear genomes and a geometric morphometric analysis of 708 modern and ancient dental remains. Our analyses demonstrate that free-living and domestic pigs in Wallacea and Oceania have diverse ancestries resulting from the introduction of multiple sequential pig populations followed by gene flow. Despite the variability in their genomic ancestry, these pigs all have a distinct tooth morphology as well as a genetic link to the Chinese domestic pig populations that accompanied the dispersal of Austronesian language speakers ~4000 to 3000 years ago via Taiwan and the Philippines. Multiple species of pigs are endemic to Maritime Southeast Asia. Some of them exhibit a distinctive tooth shape and mitochondrial DNA haplogroups, but the history of pigs in this region is not clear. Stanton et al. collected genetic data from 117 modern, historic, and ancient individuals and examined morphometric data from over 700 modern and archeological samples. After comparing with 585 published mitochondrial genomes, the authors found that domestic pigs, which were likely introduced by Austronesian-speaking groups, contributed to most pigs found today from Hawaii to the Philippines. However, early specimens from these groups show no admixture with endemic species, mirroring the lack of mixture between these early human groups with local groups during their initial migrations. ?Corinne Simont
Non‐Statistical Assembly of Donor–Acceptor Cages for Light‐Induced Charge Separation
No full textWe report light-triggered charge separation in two discrete supramolecular architectures that self-assemble in a single step from donor (D) and acceptor (A) functionalized bridging ligands and Pd(II) cations. The “shape complementary assembly” (SCA) strategy allows for exclusive formation of the cis-[Pd2D2A2]4+ cage isomer. Compared to previously reported statistical DA assemblies, lacking stoichiometry and stereo control, the number of possible electron transfer routes was reduced. This enables a better understanding and tunability of the excited state dynamics. Cage assembly was investigated by NMR, MS, and single crystal X-ray diffraction analysis. Steady-state absorption and electrochemical properties indicate that donor and acceptor moieties remain largely independent in the electronic ground state. Femtosecond pump-probe spectroscopy in the visible and infrared was applied to compare the fate of photoexcited states for pure ligands, donor- and acceptor-only assemblies, and the donor–acceptor heteroleptic cages. For the latter, ultrafast intracage ligand-to-ligand charge separation is followed by two back electron transfer pathways, occurring on timescales of hundreds of picoseconds and around one nanosecond, assignable to D/A ligands facing each other in cis- or trans-position. Our work shows that non-statistical modular self-assembly can be used for the precise positioning of photoredox-active components in defined distances on the nanoscale
Journal of Bacteriology
No full textHomologs of the polar landmark proteins HubP and FimV are widespread among bacterial species. They all share several common features, including a periplasmic LysM-like domain, a transmembrane region, an extensive cytoplasmic domain enriched in acidic amino acids, and a C-terminal tetrapeptid-repeat (TPR) domain referred to as the FimV domain. Apart from these conserved general features, however, the proteins exhibit little homology across different bacterial genera. Here, we characterized Pseudomonas putida FimV (PpFimV) with respect to cellular processes involving FimV or HubP in other species. We found that PpFimV nonspecifically binds to peptidoglycan via its periplasmic LysM domain, which, together with an immunoglobulin-like domain, is necessary for proper polar positioning. PpFimV is required for normal flagellar-mediated swimming and the placement of the chemotaxis system. However, PpFimV is not involved in regulating the number of flagellar filaments, chromosome segregation, or type IV pilus-dependent surface motility. Thus, PpFimV has surprisingly little functional overlap with, for example, HubP from Vibrio sp. or Shewanella putrefaciens or with FimV from P. aeruginosa. PpFimV was unable to compensate for the loss of SpHubP with regard to swimming in soft agar, and vice versa. Domain swapping between SpHubP and PpFimV revealed that differences in the cytoplasmic region between the transmembrane region and the C-terminal FimV domain likely account for the proteins’ distinct functions in flagella-mediated swimming. This suggests that FimV and HubP are structural homologs that have evolved to perform different, species-specific functions.IMPORTANCEMany bacterial species possess landmark proteins that organize the bacterial cell and localize specific cellular processes to the cell’s polar regions by directing client proteins or protein complexes to their designated positions. FimV and its homolog HubP are landmark proteins found in many species of the gammaproteobacteria, but their roles are not well understood. Here, we demonstrate that only certain functions related to flagella-mediated motility appear to be conserved between Pseudomonas putida FimV and Shewanella putrefaciens HubP. This finding suggests a significant degree of functional diversity
Core plasma fueling by fast inward particle transport after hydrogen pellet injection in Wendelstein 7-X
No full textGeometric obstructions for -fillings of 3-manifolds
No full textWe consider the realisation problem for normal 1-types of 4-manifolds with a given boundary. More precisely, given a normal 1-type and closed 3-dimensional -manifold , does there exist a compact 4-dimensional -manifold with boundary ? We describe a three stage obstruction theory for the existence of such a 4-manifold, with our main contribution being a `tertiary' obstruction that we describe geometrically via Wall's quadratic self-intersection form