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The research of parallel mechanism (PM) configuration involves many problems. From topology to configuration, dimensional constraint, etc., how to establish the relationship between topology and configuration with effective methods is a long-term challenge for the configuration design. In this paper, the chemical molecular spatial structure (CMSS) is linked with the configuration of symmetrical parallel mechanism (SPM). Starting from the methane molecule (CH4), a spatial structural topological relation is obtained. Based on graph theory and the spatial structural topological relation, a new expression method with topological graph and its kinematic pair adjacency matrix for spatial SPM is proposed. Then, the expression and analysis for the characteristics of spatial SPM are obtained. Finally, by taking the 3-RPS PM and the 3-RRC PM as examples, the effectiveness and corresponding consistency of the proposed expression method are successfully verified. The proposed new expression method paves the way for the subsequent digital and automated design and analysis of the SPM configuration.
The coronavirus disease (COVID-19) pandemic and resulting restrictions on physical access to long-term care homes culminated in health declines for older adults living there and their families. Knowledge gaps exist regarding maintaining social connectedness when physically separated. The study aimed to explore family members’ perceptions of the impact that restrictions on physical access to long-term care homes had on the experience of social connectedness between family members and older adults living in long-term care. The method used was a qualitative description, using in-depth semi-structured interviews. Themes arising from inductive qualitative content analysis of 21 interviews with family members included: (a) lack of connection threatening mental, emotional health, and physical health; (b) navigating trust in the unknown; (c) feelings of stress and anxiety for family members; and (d) technology – an asset, but not for everyone. Study findings suggest more emphasis should be placed on supporting social connections between older adults and their families in the context of long-term care beyond COVID-19.
Eigenvectors of the observability and controllability Gramians represent responsive and receptive flow structures that enjoy a well-established connection to resolvent forcing and response modes. However, whereas resolvent modes have demonstrated great potential to guide sensor and actuator placement, observability and controllability modes have been leveraged exclusively in the context of model reduction via input and output projections. In this work, we introduce interpolatory, rather than orthogonal, input and output projections, that can be leveraged for sensor and actuator placement and open-loop control design. An interpolatory projector is an oblique projector with the property of preserving certain entries in the vector being projected. We review the connection between the resolvent operator and the Gramians, and present several numerical examples where we perform both orthogonal and interpolatory input and output projections onto the dominant forcing and response subspaces. Input projections are used to identify dynamically relevant disturbances, place sensors to measure disturbances, and place actuators for feedforward control in the linearized Ginzburg–Landau equation. Output projections are used to identify coherent structures and place sensors aiming at state reconstruction in the turbulent flow in a minimal channel at $Re_{\tau }=185$. The framework does not require data snapshots and relies only on knowledge of the steady or mean flow.
Este trabajo busca conocer las estrategias tecnológicas, los rangos de acción y la conectividad en las estrategias humanas de ambientes marginales. Se discute, para el caso del sur de Mendoza, el modelo clásico de trashumancia cazadora recolectora entre tierras bajas y altas. El estudio se centra específicamente en El Payén y en el uso de la obsidiana andina Laguna del Maule. En El Payén, esta obsidiana ocupa el primer lugar entre las variedades conocidas y su uso se vinculó a circuitos de movilidad estacional que involucraban tierras bajas y altas. La obsidiana Laguna del Maule posee dos subtipos geoquímicos, el Subtipo 1 registrado en cordillera, y el Subtipo 2 localizado en depósitos fluviales distales. En este trabajo modelamos las estrategias de interacción de tierras altas con tierras bajas, enfocándonos en modelos propuestos para La Payunia, que ponen énfasis en la tecnología lítica y se articulan con análisis geoquímicos y geoarqueológicos. Los resultados sostienen que las poblaciones de El Payén obtenían este recurso mediante distintas estrategias tecnológicas: un aprovisionamiento serial del Subtipo 2, con circuitos de movilidad centrados en tierras bajas; diferente al Subtipo 1 de aprovisionamiento cíclico, que habría involucrado la interacción entre tierras altas y tierras bajas.
The HOLLYWOOD sign is arguably the world's most famous language object. Emblematic of prestige and cultural capital, the sign can be found not just in Los Angeles, but in citations all over the world. Beginning with the history of its valorization, HOLLYWOOD is shown to emanate symbolic value through a set of enregistered semiotic features. Drawing upon a set of globally sourced citations of HOLLYWOOD, the circulation and stratified bundling of size, emplacement, alignment, typeface, and color indicates how the citation of language objects is mediated by political economy. A process of diffuse citation is further observed, in which the quotation of language features is not overt, but the source of emanation is still tangible, revealing HOLLYWOOD as the source of a global linguistic-semiotic register. As this register circulates in citations overt and diffuse, language objects are revealed as key sites for the reproduction of commodity values. (The Hollywood sign, language object, citation, enregisterment, global emblems, recontexualization)*
This paper gives an explicit version of Selberg’s mean-value estimate for the prime number theorem in intervals, assuming the Riemann hypothesis [25]. Two applications are given to short-interval results for primes and for Goldbach numbers. Under the Riemann hypothesis, we show there exists a prime in $(y,y+32\,277\log ^2 y]$ for at least half the $y\in [x,2x]$ for all $x\geq 2$, and at least one Goldbach number in $(x,x+9696 \log ^2 x]$ for all $x\geq 2$.
This article addresses the beginnings of the twinning relationship between Coventry and Kiel to introduce and exemplify the idea of ‘urban internationalism’ as a new lens onto urban histories of town twinning initiatives and a contribution to the historiography of British town twinning. Focusing on paradiplomatic initiatives by municipal officials, religious dignitaries and other citizens in Coventry and Kiel, the article examines the role that cities played in British–German reconstruction and reconciliation in the period from the end of World War II until the formation of the Federal Republic of Germany in 1949.
The in vitro culture of domestic cat embryos without the zona pellucida affects their implantation capacity. MicroRNAs (miRNAs) have an important role in embryo–maternal communication and implantation. The objective of this study was to evaluate the expression of specific miRNAs in domestic cat blastocysts cultured without the zona pellucida. Two experimental groups were done: (1) domestic cat embryos cultured with the zona pellucida (zona intact control group, ZI); and (2) cultured without the zona pellucida (zona free group, ZF). The cleavage, morula and blastocyst rates were evaluated. The blastocysts and their spent medium were used for miRNA expression analysis using RT-qPCR (miR-21, miR-24, mi25, miR-29, miR-96, miR-98, miR-103, miR-191, miR-196, miR-199, miR-130, miR-155 and miR-302). The pre-mature microRNAs (pre-miRNAs) and miRNAs were evaluated in the blastocysts and only miRNAs were evaluated in the spent medium. No differences were observed in the cleavage, morula and blastocyst rates between the ZF and ZI groups (P > 0.05). For miRNAs analysis, miR-103 and miR-191 had the most stable expression and were selected as internal controls. ZF blastocysts had a higher expression of miR-21, miR-25, miR-29 and miR-199 and a lower expression of miR-96 than their ZI counterparts (P < 0.05). Furthermore, higher levels of miR-21, miR-25 and miR-98 were detected in the spent medium of ZF blastocysts (P < 0.05). In conclusion, in vitro culture of domestic cat embryos without the zona pellucida modifies the expression of miR-21, miR-25, miR-29, miR-199 and miR-96 at the blastocyst stage and the release of miR-21, miR-25 and miR-98.
This article provides a fresh perspective on the history of East German town twinning in the early era of détente. While previous studies have analysed East German town twinning solely as an instrument of the Socialist Unity Party (Sozialistische Einheitspartei Deutschlands, SED) to establish paradiplomatic relations in Western Europe, I explore the dynamic inter-relation between global, national and local actors and the ambiguities of urban détente. I reveal the importance of the German Association of Towns and Municipalities (Deutsche Städte- und Gemeindetag, DStuG), the East German association of municipalities, which crucially shaped the East German concept of urban détente through practising trans-local exchange. The role played by the DStuG was backed by the United Towns Organization (UTO), a non-governmental organization founded in 1957 whose aim was to form a global network of cities beyond the East–West divide. In 1960, the DStuG joined the UTO as a member and consciously used its new position to expand its scope and improve its national status through actively working on the conceptualization of urban détente. However, the conflicts between the East German foreign ministry and the UTO grew bigger, resulting in the marginalization of the DStuG and town twinning in the SED’s concept of détente. These conflicts encouraged the UTO to redefine its global approach.
Dissolved inorganic carbon (DIC) in ocean water is a major sink of fossil fuel derived CO2. Carbon isotopes in DIC serve as tracers for oceanic water masses, biogeochemical processes, and air-sea gas exchange. We present a timeseries of surface DIC δ13C and Δ14C values from 2011 to 2022 from Newport Beach, California. This is a continuation of previous timeseries (Hinger et al. 2010; Santos et al. 2011) that together provide an 18-year record. These data show that DIC Δ14C values have declined by 42‰ and that DIC δ13C values have declined by 0.4‰ since 2004. By 2020, DIC Δ14C values were within analytical error of nearby clean atmospheric CO2 Δ14C values. These long-term trends are likely the result of significant fossil fuel derived CO2 in surface DIC from air-sea gas exchange. Seasonally, Δ14C values varied by 3.4‰ between 2011 and 2022, where seasonal δ13C values varied by 0.7‰. The seasonal variation in Δ14C values is likely driven by variations in upwelling, surface eddies, and mixed layer depth. The variation in δ13C values appears to be driven by isotopic fractionation from marine primary producers. The DIC δ13C and Δ14C values record the influence of the drought that began in 2012, and a major upwelling event in 2016.
The article reflects upon the observational practices and methods developed by the early exponents of ethology committed to naturalistic field study and explores how their approaches and techniques influenced a wider field of popular natural-history filmmaking and photography. In doing so, my focus is upon three aspects of ethological field studies: the socio-technical devices used by ethologists to bring birds closer to them, the distinctive observational and representational practices which they forged, and the analogies they used to codify behaviour. This assemblage of elements included hides or screens from which to watch wild birds without disturbing them, optics to extend human vision, pens and paper to sketch and fix patterns of behaviour, watches to record timings, photography to capture action and freeze movement, and illustration and photographs to visualize behaviour. Carried through natural-history networks, the practices, methods and theories of ethologists like Huxley and Tinbergen influenced popular natural-history filmmaking and photography more broadly from the 1940s, driving a behavioural turn in these cultural practices. This popularization of the ‘ethological eye’ was further facilitated by the convergence of socio-technical devices, forms of observation and dramatization in the work of the early exponents of naturalistic field studies of birds and the popular filmmakers.