138 research outputs found
Utilising neural networks and closed form solutions to determine static creep behaviour and optimal polypropylene amount in bituminous mixtures
An institutional theory of informal entrepreneurship: some lessons from FYR Macedonia
In recent years, a new institutionalist theory has emerged to explain the prevalence of informal sector entrepreneurship. This argues that formal institutional failures lead to the emergence of an asymmetry between the formal rules (laws and regulations) and the norms, values and beliefs of entrepreneurs regarding the acceptability of participating in the informal sector, which in turn leads to the prevalence of informal entrepreneurship. The aim of this paper is to evaluate this social actor approach by reporting evidence from 453 face-to-face interviews with a nationally representative sample of entrepreneurs in FYR Macedonia. This reveals not only a significant association between participation in the informal economy and the non-alignment of entrepreneurs' views with the formal rules, but specific formal institutional failings that are significantly associated with the acceptability of informal entrepreneurship, namely poor quality public services, a lack of tax fairness, corruption and instability in the formal institutions. The theoretical and policy implications are then discussed
Spatial and temporal heterogeneity in human mobility patterns in Holocene Southwest Asia and the East Mediterranean
We present a spatiotemporal picture of human genetic diversity in Anatolia, Iran, Levant, South Caucasus, and the Aegean, a broad region that experienced the earliest Neolithic transition and the emergence of complex hierarchical societies. Combining 35 new ancient shotgun genomes with 382 ancient and 23 present-day published genomes, we found that genetic diversity within each region steadily increased through the Holocene. We further observed that the inferred sources of gene flow shifted in time. In the first half of the Holocene, Southwest Asian and the East Mediterranean populations homogenized among themselves. Starting with the Bronze Age, however, regional populations diverged from each other, most likely driven by gene flow from external sources, which we term “the expanding mobility model.” Interestingly, this increase in inter-regional divergence can be captured by outgroup-f-based genetic distances, but not by the commonly used F statistic, due to the sensitivity of F, but not outgroup-f, to within-population diversity. Finally, we report a temporal trend of increasing male bias in admixture events through the Holocene
Molecular mechanism of the priming by jasmonic acid of specific dehydration stress response genes in Arabidopsis
Pig domestication and human-mediated dispersal in western eurasia revealed through ancient DNA and geometric morphometrics
Zooarcheological evidence suggests that pigs were domesticated in Southwest Asia ∼8,500 BC. They then spread across the Middle and Near East and westward into Europe alongside early agriculturalists. European pigs were either domesticated independently or more likely appeared so as a result of admixture between introduced pigs and European wild boar. As a result, European wild boar mtDNA lineages replaced Near Eastern/Anatolian mtDNA signatures in Europe and subsequently replaced indigenous domestic pig lineages in Anatolia. The specific details of these processes, however, remain unknown. To address questions related to early pig domestication, dispersal, and turnover in the Near East, we analyzed ancient mitochondrial DNA and dental geometric morphometric variation in 393 ancient pig specimens representing 48 archeological sites (from the Pre-Pottery Neolithic to the Medieval period) from Armenia, Cyprus, Georgia, Iran, Syria, and Turkey. Our results reveal the first genetic signatures of early domestic pigs in the Near Eastern Neolithic core zone. We also demonstrate that these early pigs differed genetically from those in western Anatolia that were introduced to Europe during the Neolithic expansion. In addition, we present a significantly more refined chronology for the introduction of European domestic pigs into Asia Minor that took place during the Bronze Age, at least 900 years earlier than previously detected. By the 5th century AD, European signatures completely replaced the endemic lineages possibly coinciding with the widespread demographic and societal changes that occurred during the Anatolian Bronze and Iron Ages
Archaeogenetic analysis of Neolithic sheep from Anatolia suggests a complex demographic history since domestication
Yurtman, ozer, Yuncu et al. provide an ancient DNA data set to demonstrate the impact of human activity on the demographic history of domestic sheep. The authors demonstrate that there may have been multiple domestication events with notable changes to the gene pool of European and Anatolian sheep since the Neolithic. Sheep were among the first domesticated animals, but their demographic history is little understood. Here we analyzed nuclear polymorphism and mitochondrial data (mtDNA) from ancient central and west Anatolian sheep dating from Epipaleolithic to late Neolithic, comparatively with modern-day breeds and central Asian Neolithic/Bronze Age sheep (OBI). Analyzing ancient nuclear data, we found that Anatolian Neolithic sheep (ANS) are genetically closest to present-day European breeds relative to Asian breeds, a conclusion supported by mtDNA haplogroup frequencies. In contrast, OBI showed higher genetic affinity to present-day Asian breeds. These results suggest that the east-west genetic structure observed in present-day breeds had already emerged by 6000 BCE, hinting at multiple sheep domestication episodes or early wild introgression in southwest Asia. Furthermore, we found that ANS are genetically distinct from all modern breeds. Our results suggest that European and Anatolian domestic sheep gene pools have been strongly remolded since the Neolithic
Biocompatible ZnS:Mn quantum dots for reactive oxygen generation and detection in aqueous media
Ecological Risks Assessment and Pollution Source Identification of Trace Elements in Contaminated Sediments from the Pearl River Delta, China
- …