Developmental stability is the tendency of morphological traits to resist the effects of developmental noise, and isWe found that 406 deficiencies significantly affected the mean of morphological traits, and 92 deficiencies increased FA. These results suggest that several genomic regions have the potential to affect developmental stability. They also suggest the possibility of the existence of trait-specific and trait-nonspecific mechanisms for stabilizing developmental processes. The new findings in this study could provide insight into the understanding of the genetic architecture underlying developmental stability.
It is well known that the similarity in species composition between two communities decays with the geographic distance that separates them. It is thus likely that the similarity in the dynamics of two communities also decays with distance, because the distance-decay relationship is fundamental in nature. However, the distancedecay relationships of community dynamics have not yet been revealed. We used transition matrix models to evaluate distance-decay relationships of seasonal community dynamics (from spring to summer) in rocky intertidal sessile assemblages along the Pacific coast of Japan between 31°N and 43°N. We evaluated the distance-decay relationships of whole-community dynamics and of three dynamics-related components-recruitment, disturbance, and species interaction (competition and facilitation)-for communities separated by distances ranging from several meters to thousands of kilometers. The similarity of the recruitment dynamics among communities declined rapidly with distance within the fine spatial scale, but only moderately within larger scales. The similarity of the disturbance dynamics was independent of distance, and the similarity of species interaction declined slightly with increasing distance. The similarity of whole-community dynamics declined rapidly with distance at a fine spatial scale and moderately at larger scales. The fact that the distance-decay relationship of whole-community dynamics was similar to that of recruitment may suggest that recruitment processes are the most important determinant of spatial variability of community dynamics at our study sites during the study period.
18Fluctuating asymmetry (FA), defined as random deviation from perfect symmetry, has been used to 19 assay the inability of individuals to buffer their developmental processes from environmental 20 perturbations (i.e., developmental instability). In this study, we aimed to characterize the natural 21 genetic variation in FA of wing shape in Drosophila melanogaster, collected from across the 22 Japanese archipelago. We quantified wing shapes at whole wing and partial wing component levels 23 and evaluated their mean and FA. We also estimated the heritability of the mean and FA of these 24 traits. We found significant natural genetic variation in all the mean wing traits and in FA of one of 25 the partial wing components. Heritability estimates for mean wing shapes were significant in two 26 and four out of five wing traits in males and females, respectively. On the contrary, heritability 27 estimates for FA were low and not significant. This is a novel study of natural genetic variation in 28 FA of wing shape. Our findings suggest that partial wing components behave as distinct units of 29 selection for FA, and local adaptation of the mechanisms to stabilize developmental processes occur 30 in nature. 31 32
Many cities are prone to land subsidence, particularly due to the overuse of ground water. However, because man-made structures are normally built upon foundations that are stiffer than the surrounding ground, such structures react to land subsidence to a lesser extent. This settlement mismatch between ground and buildings, also known as differential settlement (DS), may cause serious problems in urban management, such as foundation overloading due to down-drag forces and damage to underground pipelines. Here, we present a technique for determining DS from multi-temporal satellite synthetic aperture radar (SAR) images. Permanent scatterers originating from ground and man-made structures are extracted using the differential interferometric SAR (DInSAR) technique, whereupon the DS is obtained by subtracting the settlement of the former from that of the latter. For validation purposes, we demonstrate that the estimated DS in Bangkok is consistent with field observations. Keywords: differential settlement; differential interferometric synthetic aperture radar (DInSAR); persistent scatterer interferometry (PSI) IntroductionCities all over the world have developed rapidly in recent decades, and many have suffered land subsidence due to excessive extraction of ground water, e.g., the Mekong Delta in Vietnam [1] and the Konya Plain in Turkey [2]. This has had considerable negative impacts on those cities, such as increased risk of flooding in coastal areas, cracks in buildings and infrastructure, destruction of local groundwater systems, tension cracks on land and the reactivation of existing faults. Among these various negative impacts, we focus especially on the settlement mismatch between the ground and buildings. This can cause serious problems for urban management, such as building instability and damage to underground pipelines. In the field of geotechnical engineering, this phenomenon is generally referred to as differential settlement (DS) [3,4].Land subsidence has been a serious problem in the city of Bangkok in Thailand, particularly in the early 1980s, when ground subsidence rates as high as 120 mm per year were reported [5]. The ground formation in Bangkok is soft clay with a thickness of 12-16 m, underlain by medium clay, followed by the first stiff clay layer. The first sand layer (Upper Bangkok aquifer) is then encountered at 22-24 m in the inner city area [5]. Because the soft clay layer is highly compressible, most buildings in the city are supported by piles. A normal design practice is to set the tips of piles for low-and mid-rise buildings in the first sand layer. The tips of piles for high-rise buildings are normally located in the second sand layer, which lies at a depth of 30-58 m from the ground surface [6]. Based on [6], the compression in the first 50 m of depth contributes to 30-50% of the total settlement observed at the ground surface. Because the piles are stiffer than the soft clay layer, the ground around a building will settle faster than the building. Figure 1 shows examples of DS encoun...
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