The Impact of the Dynamics of Agglomeration Externalities on Air Pollution: Evidence from Urban Panel Data in China

Air pollution in China has become a matter of increasing public concern. In this paper, we attempted to build a theoretical model to explore the impact of the dynamics of agglomeration externalities on haze pollution in urban China, where agglomeration is differentiated by regional specialization and geographical concentration. Based on China’s panel data for 289 cities during the period of 1998–2018, the empirical result shows that the relationship between industrial agglomeration and urban haze pollution is not simply linear or of an inversed U-type but turns out to be dynamically N-shaped. To be specific, the increase in local haze pollution can be explained by agglomeration externalities in the beginning stage, whereas the reducing effect only occurs during the mature stage. The heterogeneity test indicated that the effect of the type of agglomeration on haze pollution seems to be mixed in different groups of cities, but is still consistent with the hypothesis of the dynamic change of agglomeration externalities. The results are found to be quite robust and consistent after replacing variables and using other regression methods. This paper provides answers to the question of how to coordinate the relationship between developing industry parks and air pollution in terms of the life cycle of agglomeration as well as the types of city.

Rebuilding a Cluster While Protecting Knowledge within Low-Medium-Tech Supplier SMEs: A Spanish and French Comparison

Most of SMEs are engaged in open innovation practices, but they do not benefit from open innovation or from patenting in the same way as larger firms do. At the same time SMEs, as territorialized suppliers, play a crucial role within evolving regional specialization. In this context the purpose of our study is to examine how low and medium technology supplier SMEs learn and organize themselves at a territorial level to address the challenge of IP protection in an open innovation paradigm. We used a qualitative method with a longitudinal multi-case study involving 27 companies with a historical lance to compare the territorial dynamics of knowledge protection within clustered supplier SMEs in two European regions. The results show they protect their knowledge by learning how to design, in a direct relationship with clients, customized complex technological products to develop a new organizational matrix of multidisciplinary knowledge that reveals itself difficult to imitate within the clusters. They also cope with other supplier firms across sectors even if they show societal path dependencies in the way to build cooperation. This dynamic has given birth to changing structural relationships among regionally clustered SMEs and between them and large firms.

A transcriptomic atlas of mouse cerebellar cortex comprehensively defines cell types

The cerebellar cortex is a well-studied brain structure with diverse roles in motor learning, coordination, cognition and autonomic regulation. However, a complete inventory of cerebellar cell types is currently lacking. Here, using recent advances in high-throughput transcriptional profiling1–3, we molecularly define cell types across individual lobules of the adult mouse cerebellum. Purkinje neurons showed considerable regional specialization, with the greatest diversity occurring in the posterior lobules. For several types of cerebellar interneuron, the molecular variation within each type was more continuous, rather than discrete. In particular, for the unipolar brush cells—an interneuron population previously subdivided into discrete populations—the continuous variation in gene expression was associated with a graded continuum of electrophysiological properties. Notably, we found that molecular layer interneurons were composed of two molecularly and functionally distinct types. Both types show a continuum of morphological variation through the thickness of the molecular layer, but electrophysiological recordings revealed marked differences between the two types in spontaneous firing, excitability and electrical coupling. Together, these findings provide a comprehensive cellular atlas of the cerebellar cortex, and outline a methodological and conceptual framework for the integration of molecular, morphological and physiological ontologies for defining brain cell types.

The structure of the sowing areas of crops in the Non-chernozem region

The article provides a current regional specialization of agricultural production in the subjects of the Non-chernozem economic zone of the country and its socio-economic features happened by 2016. The special attention is paid to grain cultures, dairy and meat cattle breeding, pig breeding and poultry farming. It is predicted that dairy cattle, which ensures the employment of a significant number of workers in agricultural organizations and farms, remain a basic agricultural activity in rural life of Non-chernozem region, maintaining the productivity of cold regions. There are seven such regions having more or less favorable territories for agricultural production. It seems possible to cultivate full range of crops there. The calculation of the size of the sowing areas per one cattle head in the subjects of Nonchernozem region are considered in this paper. It has been established that the structure of sowing areas in agricultural organizations of the studied regions does not have significant differences compared to peasant farms. The exception is potatoes and vegetables, sowing areas of which are significantly higher in small forms of land use. With a low level of mechanization of agricultural production in small forms of management, (with the exception of few cultivated crops), the growth of production does not lead to increase of effectiveness. In the medium term, according to the authors estimation, the existing practice of concentrating the agricultural production in the territories with the most favorable agro-climatic, soil conditions and favorable position regarding consumer markets will be preserved.

Location Matters: Navigating Regional Heterogeneity of the Neurovascular Unit

The neurovascular unit (NVU) of the brain is composed of multiple cell types that act synergistically to modify blood flow to locally match the energy demand of neural activity, as well as to maintain the integrity of the blood-brain barrier (BBB). It is becoming increasingly recognized that the functional specialization, as well as the cellular composition of the NVU varies spatially. This heterogeneity is encountered as variations in vascular and perivascular cells along the arteriole-capillary-venule axis, as well as through differences in NVU composition throughout anatomical regions of the brain. Given the wide variations in metabolic demands between brain regions, especially those of gray vs. white matter, the spatial heterogeneity of the NVU is critical to brain function. Here we review recent evidence demonstrating regional specialization of the NVU between brain regions, by focusing on the heterogeneity of its individual cellular components and briefly discussing novel approaches to investigate NVU diversity.