Recent Applications of Heteropolyacids and Related Compounds in Heterocycle Synthesis. Contributions between 2010 and 2020

Over the past two decades, polyoxometalates (POM) have received considerable attention as solid catalysts, due to their unique physicochemical characteristics, since, first, they have very strong Bronsted acidity, approaching the region of a superacid, and second, they are efficient oxidizers that exhibit rapid redox transformations under fairly mild conditions. Their structural mobility is also highlighted, since they are complex molecules that can be modified by changing their structure or the elements that compose them to model their size, charge density, redox potentials, acidity, and solubility. Finally, they can be used in substoichiometric amounts and reused without an appreciable loss of catalytic activity, all of which postulate them as versatile, economic and ecological catalysts. Therefore, in 2009, we wrote a review article highlighting the great variety of organic reactions, mainly in the area of the synthesis of bioactive heterocycles in which they can be used, and this new review completes that article with the contributions made in the same area for the period 2010 to 2020. The synthesized heterocycles to be covered include pyrimidines, pyridines, pyrroles, indoles, chromenes, xanthenes, pyrans, azlactones, azoles, diazines, azepines, flavones, and formylchromones, among others.

Subjects of Agricultural Production in the Socio-Structural Processes of the Russian Village

The article deals with the subjects of agricultural production, agricultural organizations, agricultural Holdings, peasant farms, personal part-time farms and their participation in the sociostructural processes of the Russian village. Dynamics of changes in the agricultural labor market, based on data from several large-scale studies of Rosstat (2011–2018), covering all regions of Russia. Results of individual interviews of the rural population and surveys of their households, as well as the Results of the 2016 agricultural census. they show the specificity of the moment of the rural world, when institutional transformations caused by agrarian reforms and modernization of agriculture radically changed social, labor practices and everyday life of the villagers. For a quarter of a century, the socioeconomic situation and status of the majority of villagers has changed qualitatively. The decrease in the level of rural employment in agriculture and growth in non-agricultural sectors of the agriculture industry led to structural mobility (move), which had transformed the social structure of the village and the formation of the informal sector, with its own internal structure, constituting one-third of all employees. These processes have led to an increase in migration of the working-age population, which has led to a decrease in the quality of human capital and the prospects for its reproduction in rural areas.

Triple Disadvantage: Neighborhood Networks of Everyday Urban Mobility and Violence in U.S. Cities

This article develops and assesses the concept of triple neighborhood disadvantage. We argue that a neighborhood’s well-being depends not only on its own socioeconomic conditions but also on the conditions of neighborhoods its residents visit and are visited by, connections that form through networks of everyday urban mobility. We construct measures of mobility-based disadvantage using geocoded patterns of movement estimated from hundreds of millions of tweets sent by nearly 400,000 Twitter users over 18 months. Analyzing nearly 32,000 neighborhoods and 9,700 homicides in 37 of the largest U.S. cities, we show that neighborhood triple disadvantage independently predicts homicides, adjusting for traditional neighborhood correlates of violence, spatial proximity to disadvantage, prior homicides, and city fixed effects. Not only is triple disadvantage a stronger predictor than traditional measures, it accounts for a sizable portion of the association between residential neighborhood disadvantage and homicides. In turn, potential mechanisms such as neighborhood drug activity, interpersonal friction, and gun crime prevalence account for much of the association between triple disadvantage and homicides. These findings implicate structural mobility patterns as an important source of triple (dis)advantage for neighborhoods and have implications for a broad range of phenomena beyond crime, including community capacity, gentrification, transmission in a pandemic, and racial inequality.

Institutional Determinants of Forming the Management Capital: A Case of Ukrainian Healthcare Sector

Medical establishment is a complex socio-economic system, whose sustainable development should be ensured by the modern management practices. Problems of management of medical establishment have not been still considered in the context of the current reformation of healthcare sector and still this social and economic field does not report to the conditions of market mechanism. The main goal of this paper is to analyze a structure of total capital of modern medical establishment and the place and role of managerial capital in this structure. Methodology. This study combines economic analysis of concepts of total capital, physical capital, financial capital, intellectual capital and managerial capital. In this study complex of the general scientific and special research methods were used to achieve the goal of the study. The method of logical analysis of the literature was used. The structural analysis was used with purpose to generate the structure of total capital and its key elements of medical establishment. Method of summarization was used to make a conclusion. Scientific works of national and foreign leading scientists in this sphere were used as the informational basis for the conducted research. Findings. In the paper the issue of managerial capital of a medical establishment as a complex socio-economic system is researched. A structure of total capital of medical establishment with its main components, such as physical, financial and intellectual capital, is proposed. In their turn, the theoretical concept of intellectual capital considers the following its elements: human capital, organizational capital and consumer’s capital. Managerial capital is viewed as a meta-capital within the frameworks of proposed structure and is an effective management tool for medical establishments’ business processes and qualitative composition of all types of capital, which pursues the sustainable development of medical establishment. Main tasks of formation, development and reproduction of managerial capital of medical establishment are researched. Also the issues of institutional environment of forming management capital are researched. Key institutional determinants, such innovation, investment and structural mobility are considered. Practical implications. In the conditions of creating by Ukraine the new national healthcare system the issue of formation and development of managerial capital in healthcare sphere is of great importance. It should be considered in the current process of Ukrainian healthcare system’s reformation to avoid the mistakes. Value (originality). The results of conducted research could be a framework for formation of managerial capital of the medical

Kinematic topology and constraints of multi-loop linkages

SUMMARYModeling the instantaneous kinematics of lower pair linkages using joint screws and the finite kinematics with Lie group concepts is well established on a solid theoretical foundation. This allows for modeling the forward kinematics of mechanisms as well the loop closure constraints of kinematic loops. Yet there is no established approach to the modeling of complex mechanisms possessing multiple kinematic loops. For such mechanisms, it is crucial to incorporate the kinematic topology within the modeling in a consistent and systematic way. To this end, in this paper a kinematic model graph is introduced that gives rise to an ordering of the joints within a mechanism and thus allows to systematically apply established kinematics formulations. It naturally gives rise to topologically independent loops and thus to loop closure constraints. Geometric constraints as well as velocity and acceleration constraints are formulated in terms of joint screws. An extension to higher order loop constraints is presented. It is briefly discussed how the topology representation can be used to amend structural mobility criteria.

Analysis of Local Variability and Allostery in Macromolecular Assemblies using Cryo-EM and Focused Classification

Single-particle electron cryo-microscopy and computational image classification can be used to analyze structural variability in macromolecules and their assemblies. In some cases, a particle may contain different regions that each display a range of distinct conformations. We have developed strategies, implemented within the Frealign andcisTEM image processing packages, to focus classify on specific regions of a particle and detect potential covariance. The strategies are based on masking the region of interest using either a 2-D mask applied to reference projections and particle images, or a 3-D mask applied to the 3-D volume. We show that focused classification approaches can be used to study structural allostery, a concept that is likely to gain more importance as datasets grow in size, allowing the distinction of more structural states and smaller differences between states. Finally, we apply the approaches to an experimental dataset containing the HIV-1 Transactivation Response (TAR) element RNA fused into the large bacterial ribosomal subunit, to deconvolve structural mobility within localized regions of interest.HighlightsDescription of different image classification strategies in single-particle cryo-EMQuantitative evaluation of two classification methods using simulated dataApplication of the two classification methods to an experimental dataset

Social mobility in Mexico. Trends, Recent Findings and Research Challenges

La recesión de los años ochenta y la subsecuente reestructuración económica tuvieron un profundo impacto en la sociedad mexicana. No obstante, sus consecuencias sobre la movilidad social no fueron analizadas hasta finales de los noventa, cuando una serie de estudios empíricos revelaron las continuidades y los cambios en los patrones de movilidad social. En este artículo se discuten cuatro tendencias recientes: la continuidad de las altas tasas absolutas de movilidad intergeneracional; la reducción de las recompensas monetarias asociadas a la movilidad ocupacional; la creciente rigidez en las tasas relativas de movilidad; y el ajuste del caso mexicano al patrón de movilidad general propuesto por Erikson y Goldthorpe. El panorama que resulta de estas tendencias es el de una sociedad que, a pesar los efectos negativos de la crisis y los cambios estructurales de los años ochenta y noventa, ha mantenido altas tasas de movilidad social, pero sufre en otros aspectos como la calidad de las oportunidades de movilidad ascendente y la creciente desigualdad de oportunidades asociada a los orígenes de clase. El artículo concluye con una discusión sobre posibles líneas futuras de investigación de los estudios sobre movilidad social en México.Abstract: The recession of the 1980s and subsequent economic restructuring in the 1990s had a profound impact on Mexican society. However, the consequences in social mobility were not fully explored until the end of the 1990s, when a series of empirical studies revealed continuities and changes in mobility patterns. The purpose of this article is to discuss trends in intergenerational social mobility. Four findings are discussed: the continuity of high overall and upward mobility rates; the reduction of monetary gains associated to upward occupational mobility; the increasing rigidity in relative rates of occupational mobility; and the overall compliance of the Mexican case to Erikson and Golthorpe’s core model of social fluidity. The picture emerging from these findings depicts a society that, notwithstanding the negative effects of the economic recession and structural changes of the 1980s and 1990s, maintained high rates of structural mobility, but suffered in other aspects such as the decrease in the quality of opportunities of upward mobility, as well as the increasing inequality of opportunity by class origins. The article concludes with a discussion of future avenues of research for social mobility studies in Mexico.Résumé : La récession des années 1980 et la subséquente restructuration économique des années 1990 a causé un impact profond sur la société mexicaine. Néanmoins, ses conséquences sur la mobilité sociale n’ont été entièrement explorées qu’à la fin des années 1990, quand une série d’études empiriques a dévoilé des continuités et des changements dans les modèles de mobilité. Le but de cet article est d’analyser les tendances de la mobilité sociale inter générationnelle. Le débat porte sur quatre découvertes: la continuité de taux élevés d’ascension dans l’échelle sociale ; la réduction des entrées monétaires associée à une mobilité occupationnelle plus importante ; la rigidité croissante des taux relatifs à la mobilité occupationnelle ; et la totale conformité du cas mexicain au modèle type de fluidité sociale d’Erickson et Golthorpe. L’image qui émerge de ces résultats décrit une société qui, malgré les effets négatifs de la récession économique et les réformes structurelles des années 1980 et 1990, maintient de hauts indices de mobilité structurelle, mais qui paie les conséquences d’autres aspects tels que la baisse de la qualité des opportunités d’ascension dans l’échelle sociale, ainsi que l’augmentation de l’inégalité d’opportunités données par la classe d’origine. L’article conclut par une discus- sion sur les futures voies de recherche possibles pour affiner les études sur la mobilité sociale au Mexique.

Quantification of vertical free moment induced by the human foot–ankle complex during axial loading

Axial loading of the human cadaver lower leg is known to generate eversion of the calcaneus and internal rotation of the tibia if the plantar surface of the foot does not slide on the floor. Such kinematic coupling between calcaneal eversion and internal tibial rotation has been described previously, but no studies have actually quantified the innate ability of the human foot to generate ground reaction moment around the vertical axis of the floor (vertical free moment) due to axial loading of the human cadaver lower leg. This study investigated the vertical free moment generated by eight cadaveric lower leg specimens loaded vertically with traction of the Achilles’ tendon using a six-component force plate. The vertical free moments in all specimens were oriented toward the direction of internal rotation, and the mean magnitude of the vertical free moments was −1.66 N m when an axial load of 450 N was applied. A relatively large ground reaction moment can be applied to the body during walking due to the innate structural mobility of the foot. The structurally embedded capacity of the human foot to generate the vertical free moment may facilitate compensation of the moment generated around the vertical axis of the body during walking due to trunk rotation and leg swing.

EDUCATION AND EQUALITY

This article explores how in the postwar years education was constructed as the main way in which a meritocratic society could be created in Britain (but also elsewhere). The concept of meritocracy, that is to say of a just society in which equality of opportunities and education for all, would ostensibly provide the basis with which labor market allocation would be realized. As this article argues, nothing in education operates outside the wider political economy, which in capitalism is inherently unequal as it is underpinned by the existence of antagonistically opposed social classes, separated from each other by unequal access to the means of production. As such, the circulation in the British social system that occurred in the early postwar years was not the result of decreasing inequalities within the class structure but rather the product of the occupational restructuring that fostered high rates of structural mobility. Consequently, “ascription” rather than “ability” continued to facilitate labor market stratification.