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This paper focuses on urban discourses as powerful instruments intertwined with the dialectic of inclusion and exclusion. First, three dominant contemporary urban discourses developed in the field of urban planning are scrutinized on their inclusiveness of families and daily family life. The attractive city, the creative city and the city as an emancipation machine are examples of urban discourses communicated top-down via reports, debates and media attention. It is argued that these three discourses do not address families as urban citizens nor the very notion of reproduction and its daily manifestation. The exclusionary character of contemporary urban discourses does not only result in a neglect of urban families, it also legitimates non-intervention when it comes to family issues. This conclusion activated the search for an alternative discourse as expanded in the second part of the paper. This alternative discourse is constructed from the bottom-up and is rooted in the day-to-day experiences of urban families themselves. It is a refined discourse, with interrelated geographical scales including the city as a whole, the neighbourhood, the street and the home. This is a city that integrates—as families themselves do—the different domains of life. The city is appreciated for its qualities of proximity, the neighbourhood for its ethnically mixed children’s domains, the street as an urban haven and the house as the place that accommodates private life for each member of the family. This alternative discourse is called the balanced city. The empirical basis is drawn from middle-class urban families in Rotterdam, The Netherlands.  相似文献   
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The efficient and dense storage of hydrogen still is a challenge for research and development. Next to compression and liquefaction, there are a number of alternative approaches, which try to enhance storage density by bonding hydrogen to another substance. Physisorbing as well as chemisorbing organic and inorganic carrier systems are possible. Many of these technologies have not yet exceeded the technology readiness level of lab‐scale tests. However, some of the technologies have already reached significantly higher technological levels. The first part of this study discusses storage approaches with recovery of elemental hydrogen.  相似文献   
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In the transition period from late gestation to early lactation, dairy cows undergo tremendous metabolic changes. Insulin is a relevant antilipolytic factor. Decreasing serum concentrations of insulin and glucose, increasing serum concentrations of nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHB), and changes in body condition score (BCS) reflect the negative energy balance around calving. This study investigated peripartum metabolic adaptation in 359 primiparous and 235 multiparous German Holstein cows from a commercial dairy herd under field conditions. Body condition score was recorded and blood samples were taken 10 to 1 d prepartum, 2 to 4 d postpartum, and 12 to 20 d postpartum. Generalized mixed models and generalized estimation equations were applied to assess associations between prepartum BCS; BCS changes during the transition period; insulin, glucose, NEFA, and BHB serum concentrations; and milk yield, which was taken from an electronic milk meter from d 6 of lactation. Serum insulin concentrations of multiparous postpartum cows were lower compared with prepartum, and compared with primiparous cows. In general, primiparous cows had lower postpartum NEFA and BHB concentrations than multiparous cows. In primiparous cows, we identified a positive association between prepartum BCS and prepartum serum insulin concentration. Prepartum obese multiparous cows, but not primiparous cows, were characterized by higher postpartum serum NEFA and BHB concentrations and lower milk yield than other cows in the same parity class. Primiparous cows with a smaller degree of BCS loss during the transition period had higher postpartum insulin and lower NEFA concentrations and lower milk yield than other primiparous cows. In conclusion, primiparous cows had less lipolysis and lower milk yield than multiparous cows, associated with higher insulin concentrations. Avoiding high body condition loss during the transition period is a main factor in preventing peripartal metabolic imbalances of glucose and fat metabolism.  相似文献   
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Identifying the mechanisms by which diseases spread among populations is important for understanding and forecasting patterns of epidemics and pandemics. Estimating transmission coupling among populations is challenging because transmission events are difficult to observe in practice, and connectivity among populations is often obscured by local disease dynamics. We consider the common situation in which an epidemic is seeded in one population and later spreads to a second population. We present a method for estimating transmission coupling between the two populations, assuming they can be modelled as susceptible–infected–removed (SIR) systems. We show that the strength of coupling between the two populations can be estimated from the time taken for the disease to invade the second population. Confidence in the estimate is low if only a single invasion event has been observed, but is substantially improved if numerous independent invasion events are observed. Our analysis of this simplest, idealized scenario represents a first step toward developing and verifying methods for estimating epidemic coupling among populations in an ever-more-connected global human population.  相似文献   
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