Tendon mechanobiology in small-animal experiments during post-transection healing

Ruptures to tendons are common and costly, and no clinical consensus exists on the appropriate treatment and rehabilitation regimen to promote their healing as well as full recovery of functionality. Although mechanobiology is known to play an important role in tendon regeneration, the understanding of how mechano-regulated processes affect tendon healing needs further clarification. Many small-animal studies, particularly in rats and mice, have characterized the progression of healing in terms of geometrical, structural, compositional, mechanical, and cellular properties. Some of the properties are also studied under different mechanical loading regimens. The focus of this review is to summarize and generalize the information in the literature regarding spatial and temporal differentiation of tendon properties during rodent tendon healing following full-tendon transection, as well as how this is affected by altered in vivo loading regimens.

Temporal cell fate determination in the spinal cord is mediated by the duration of Notch signalling

During neural development, progenitor cells generate different types of neurons in specific time windows. Despite the characterisation of many of the transcription factor networks involved in these differentiation events, the mechanism behind their temporal regulation is poorly understood. To address this question, we studied the temporal differentiation of the simple lateral floor plate (LFP) domain in the zebrafish spinal cord. LFP progenitors sequentially generate early-born Kolmer-Agduhr″ (KA″) interneurons and late-born V3 interneurons. Analysis using a Notch signalling reporter demonstrates that these cell populations have distinct Notch signalling profiles. Not only do V3 cells receive higher total levels of Notch response, but they collect this response over a longer duration compared to V3 cells. To test whether the duration of Notch signalling determines the temporal cell fate specification, we combined a transgene that constitutively activates Notch signalling in the ventral spinal cord with a heat shock inducible Notch signalling terminator to switch off Notch response at any given time. Sustained Notch signalling results in expanded LFP progenitors while KA″ and V3 interneurons fail to specify. Early termination of Notch signalling leads to exclusively KA″ cell fate, despite the high level of Notch signalling, whereas late attenuation of Notch signalling drives only V3 cell fate. This suggests that the duration of Notch signalling is instructive in cell fate specification. Interestingly, knockdown experiments reveal a role for the Notch ligand Jag2b in maintaining LFP progenitors and limiting their differentiation into KA″ and V3 cells. Our results indicate that Notch signalling is required for neural progenitor maintenance while a specific attenuation timetable defines the fate of the postmitotic progeny.

Response of maize and common bean to spatial and temporal differentiation in maize-common bean intercropping

An experiment on maize (Zea mays)-common bean (Phaseolus vulgaris L.) intercropping was conducted for two years (2014 and 2016) at two locations in North western Ethiopia with the objective of determining the spatial arrangement and planting date of common bean. Common bean intercropped with maize at three planting dates (simultaneously with maize, at emergence and knee height of maize) in two spatial arrangements (alternate and paired arrangements).The experimental design was factotrial randomized complete block design with three replications. Sole maize and common bean were included as a check. Results revealed that the spatial and temporal differentiation significantly affect only the agronomic attributes of common bean in common bean-maize intercropping. At Adet the grain yield of common bean (1.9 t ha-1), LER (1.99) and MAI (357) in maize-common bean intercropping was higher when common bean was planted at the same time with maize in paired planting pattern. On the other hand, maximum LER (1.61) and MAI (2.83) at Finoteselam were observed when common bean was intercropped with maize at maize emergence in paired planting pattern. Simultaneous intercropping of common bean with maize gave more stable total land output yield as compared to other intercropping systems but showed high variability as compared to the sole cropping. Thus, it can be concluded that planting common bean simultaneously with maize in paired planting pattern at Adet and planting common bean at maize emergence at Finoteselam in maize-common bean intercropping gave maximum land use efficiency and profitability of the cropping system without reducing the main crop yield (maize).This research also suggested further research on the compatibility of various maize and common bean varieties in different spatial and temporal differentiation.

Spatial and Temporal Differentiation of the Tourism Water Footprint in Mainland China and Its Influencing Factors

While tourism generates economic benefits at destinations, it also creates certain environmental pressures. In the global context of water scarcity, the spatial and temporal differentiation characteristics of water consumption at tourism destinations have become a focus of attention. Based on panel data, the present study calculates the change trends in China’s tourism water footprint (TWF) in the 2013–2018 period using input-output analysis, analyses the regional differences in TWF changes using kernel density estimation and the Theil index, and investigates the driving factors of the spatial and temporal differentiation of the TWF using the logarithmic mean Divisia index model. The results indicate that (1) the tourism water consumption in China increased year-by-year but that the tourism water use efficiency improved; (2) the proportion of the TWF for accommodation and food in the total TWF gradually increased, while the proportion of the TWF for transportation continuously decreased; (3) the TWF of each region increased continuously, with the absolute difference between regions gradually increasing and the difference in the TWF intensity gradually decreasing; and (4) decomposition analysis showed that the TWF in China was positively driven by per capita expenditure and the number of tourists, with the role of TWF intensity shifting from inhibition to promotion, and that each driving force changed with time. Based on the spatial and temporal differences in the TWF, the provinces in China are divided into five categories, and targeted countermeasures and suggestions are proposed.

Measurement of green total factor productivity on Chinese laying hens: From the perspective of regional differences

Eggs contain the essential cholesterol and protein for the human body, which plays an irreplaceable role in human survival, production and life. There are significant differences in the development of laying hens feeding in different regions. It is of great significance to improve egg production and reduce pollution emission for China’s laying hens industry. Based on the SBM model, this paper constructs MML index, considering unexpected output under common frontier, to comprehensively evaluate the green total factor productivity on Chinese laying hens (GTCL). The results show that: (1) GTCL shows a large spatial and temporal differentiation under both the common frontier and the regional frontier. Compared with the eastern region and central region, the western region has obvious advantages in GTCL. (2) GTCL overall shows a downward trend, however, it emerges an upward trend in recent years. (3) Compared with small-scale and large-scale, middle-scale GTCL has advantages. According to the above empirical results, combined with the China’s actual national situation, this paper finally puts forward some policy recommendations to improve GTCL.

PECULIARITIES OF FORMATION OF THE LOWER CRETACEOUS TEСTONO-SEDIMENTATION SYSTEM OF THE BLACK SEA MEGADEPRESSION

Based on the analysis of the distribution of structural-material complexes, facial-genetic types and modeling of the history of immersion of the Lower Cretaceous sediments, the spatial-temporal differentiation of the tectonic regime of the Black Sea megadepression in the Early Cretaceous was established. It is shown that the structural and lithologicalfacial features of the Lower Cretaceous tectonic-sedimentation system were determined by the interaction of tectonic and geological-paleooceanographic factors. Thus, the low sea level and the initial phases of activation of sublatitudinal faults in the Hoterivian-Aptian determined the dominant influence of submeridional tectonic faults on the formation of the corresponding structural-facial block zonation. The increase in the area of the basin, the removal of denudation areas in the Late Albian reduced the intensity of terrigenous discharge, and the prolonged activity of sublatitudinal faults led to the formation of sublatitudinal structural-facial zonation. In the subsequent geological history, the tectonic regime was characterized by a complex mosaic-block character, which influenced the heterogeneity of oil and gas lithofluid systems of Cretaceous deposits.