Graphics mini manual

The computer graphics capabilities available at the Center are introduced and their use is explained. More specifically, the manual identifies and describes the various graphics software and hardware components, details the interfaces between these components, and provides information concerning the use of these components at LaRC

Cryogenic setup for trapped ion quantum computing

We report on the design of a cryogenic setup for trapped ion quantum computing containing a segmented surface electrode trap. The heat shield of our cryostat is designed to attenuate alternating magnetic field noise, resulting in 120~dB reduction of 50~Hz noise along the magnetic field axis. We combine this efficient magnetic shielding with high optical access required for single ion addressing as well as for efficient state detection by placing two lenses each with numerical aperture 0.23 inside the inner heat shield. The cryostat design incorporates vibration isolation to avoid decoherence of optical qubits due to the motion of the cryostat. We measure vibrations of the cryostat of less than $\pm$20~nm over 2~s. In addition to the cryogenic apparatus, we describe the setup required for an operation with $^{\mathrm{40}}$Ca$^{\mathrm{+}}$ and $^{\mathrm{88}}$Sr$^{\mathrm{+}}$ ions. The instability of the laser manipulating the optical qubits in $^{\mathrm{40}}$Ca$^{\mathrm{+}}$ is characterized yielding a minimum of its Allan deviation of 2.4$\cdot$10$^{\mathrm{-15}}$ at 0.33~s. To evaluate the performance of the apparatus, we trapped $^{\mathrm{40}}$Ca$^{\mathrm{+}}$ ions, obtaining a heating rate of 2.14(16)~phonons/s and a Gaussian decay of the Ramsey contrast with a 1/e-time of 18.2(8)~ms

Reframing China’s heritage conservation discourse. Learning by testing civic engagement tools in a historic rural village

Urban heritage conservation in China has been subject to severe criticism, although there is now a sense of paradigm shift. Charters, declarations and agendas had the merit of filtering down the international discourse on heritage, while more innovative approaches were arising. The UNESCO Historic Urban Landscape recommendation, offers a new angle from which to observe this process of change. The underlying argument of this article is that HUL can provide a platform to achieve greater sustainability in transforming historic sites in China, particularly in rural areas, overcoming, at the same time, the easy shortcut of the East–West discourse of difference in respect to heritage conservation. This is primarily due to the shifting focus from the materiality of heritage to its role in sustainable development with increasing attention on the role played by local communities. By presenting the proposal for the protection of the historic rural village of Shuang Wan in the Jiangsu Province, this paper aims to reflect on this shift showing its advantages but also some of the risks. These are inherent in a discourse of heritage in danger of legitimising mere pro-growth development approaches, if not accompanied by participatory practices considerate of the specific social reality of China

Involvement of the choroid plexus in Alzheimer’s disease pathophysiology: findings from mouse and human proteomic studies

Background: Structural and functional changes of the choroid plexus (ChP) have been reported in Alzheimer’s disease (AD). Nonetheless, the role of the ChP in the pathogenesis of AD remains largely unknown. We aim to unravel the relation between ChP functioning and core AD pathogenesis using a unique proteomic approach in mice and humans. Methods: We used an APP knock-in mouse model, APPNL-G-F, exhibiting amyloid pathology, to study the association between AD brain pathology and protein changes in mouse ChP tissue and CSF using liquid chromatography mass spectrometry. Mouse proteomes were investigated at the age of 7 weeks (n = 5) and 40 weeks (n = 5). Results were compared with previously published human AD CSF proteomic data (n = 496) to identify key proteins and pathways associated with ChP changes in AD. Results: ChP tissue proteome was dysregulated in APPNL-G-F mice relative to wild-type mice at both 7 and 40 weeks. At both ages, ChP tissue proteomic changes were associated with epithelial cells, mitochondria, protein modification, extracellular matrix and lipids. Nonetheless, some ChP tissue proteomic changes were different across the disease trajectory; pathways related to lysosomal function, endocytosis, protein formation, actin and complement were uniquely dysregulated at 7 weeks, while pathways associated with nervous system, immune system, protein degradation and vascular system were uniquely dysregulated at 40 weeks. CSF proteomics in both mice and humans showed similar ChP-related dysregulated pathways. Conclusions: Together, our findings support the hypothesis of ChP dysfunction in AD. These ChP changes were related to amyloid pathology. Therefore, the ChP could become a novel promising therapeutic target for AD

Nanocrystal residual strains and density layers enhance failure resistance in the cleithrum bone of evolutionary advanced pike fish

Failure resistant designs are particularly crucial for bones subjected to rapid loading, as is the case for the ambush hunting northern pike Esox lucius . These fish have slim and low density osteocyte lacking bones. As part of the swallowing mechanism, the cleithrum bone opens and closes the jaw. The cleithrum needs sufficient strength and damage tolerance, to withstand years of repetitive rapid gape and suck cycles of feeding. The thin wing shaped bone comprises anisotropic layers of mineralized collagen fibers that exhibit periodic variations in mineral density on the mm and micrometer length scales. Wavy collagen fibrils interconnect these layers yielding a highly anisotropic structure. Hydrated cleithra exhibit Young s moduli spanning 3 9 GPa where the yield stress of amp; 8764;40 MPa increases markedly to exceed amp; 8764;180 MPa upon drying. This 5x observation of increased strength corresponds to a change to brittle fracture patterns. It matches the emergence of compressive residual strains of amp; 8764;0.15 within the mineral crystals due to forces from shrinking collagen layers. Compressive stresses on the nanoscale, combined with the layered anisotropic microstructure on the mm length scale, jointly confer structural stability in the slender and lightweight bones. By employing a range of X ray, electron and optical imaging and mechanical characterization techniques, we reveal the structure and properties that make the cleithra impressively damage resistant composite

A three-dimensional view of structural changes caused by deactivation of fluid catalytic cracking catalysts

Since its commercial introduction three-quarters of a century ago, fluid catalytic cracking has been one of the most important conversion processes in the petroleum industry. In this process, porous composites composed of zeolite and clay crack the heavy fractions in crude oil into transportation fuel and petrochemical feedstocks. Yet, over time the catalytic activity of these composite particles decreases. Here, we report on ptychographic tomography, diffraction, and fluorescence tomography, as well as electron microscopy measurements, which elucidate the structural changes that lead to catalyst deactivation. In combination, these measurements reveal zeolite amorphization and distinct structural changes on the particle exterior as the driving forces behind catalyst deactivation. Amorphization of zeolites, in particular, close to the particle exterior, results in a reduction of catalytic capacity. A concretion of the outermost particle layer into a dense amorphous silica–alumina shell further reduces the mass transport to the active sites within the composite

The Long-Term Consequences of the Global 1918 Influenza Pandemic: A Systematic Analysis of 117 IPUMS International Census Data Sets

Several country-level studies, including a prominent one for the United States, have identified long-term effects of in-utero exposure to the 1918 influenza pandemic (also known as the Spanish Flu) on economic outcomes in adulthood. In-utero conditions are theoretically linked to adult health and socioeconomic status through the fetal origins or Barker hypothesis. Historical exposure to the Spanish Flu provides a natural experiment to test this hypothesis. Although the Spanish Flu was a global phenomenon, with around 500 million people infected worldwide, there exists no comprehensive global study on its long-term economic effects. We attempt to close this gap by systematically analyzing 117 Census data sets provided by IPUMS International. We do not find consistent global long-term effects of influenza exposure on education, employment and disability outcomes. A series of robustness checks does not alter this conclusion. Our findings indicate that the existing evidence on long-term economic effects of the Spanish Flu is likely a consequence of publication bias