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S. 4,[5],12:i:-, a monophasic variant of S. enterica serovar Typhimurium, is an important multidrug resistant serovar. Strains of colistin-resistant S. 4,[5],12:i:- have been reported in several countries with patients occasionally had recent histories of travels to Southeast Asia. In the study herein, we investigated the genomes of S. 4,[5],12:i:- carrying mobile colistin resistance (mcr) gene in Thailand. Three isolates of mcr-3.1 carrying S. 4,[5],12:i:- in Thailand were sequenced by both Illumina and Oxford Nanopore platforms and we analyzed the sequences together with the whole genome sequences of other mcr-3 carrying S. 4,[5],12:i:- isolates available in the NCBI Pathogen Detection database. Three hundred sixty-nine core genome SNVs were identified from 27 isolates, compared to the S. Typhimurium LT2 reference genome. A maximum-likelihood phylogenetic tree was constructed and revealed that the samples could be divided into three clades, which correlated with the profiles of fljAB-hin deletions and plasmids. A couple of isolates from Denmark had the genetic profiles similar to Thai isolates, and were from the patients who had traveled to Thailand. Complete genome assembly of the three isolates revealed the insertion of a copy of IS26 at the same site near iroB, suggesting that the insertion was an initial step for the deletions of fljAB-hin regions, the hallmark of the 4,[5],12:i:- serovar. Six types of plasmid replicons were identified with the majority being IncA/C. The coexistence of mcr-3.1 and blaCTX-M-55 was found in both hybrid-assembled IncA/C plasmids but not in IncHI2 plasmid. This study revealed possible transmission links between colistin resistant S. 4,[5],12:i:- isolates found in Thailand and Denmark and confirmed the important role of plasmids in transferring multidrug resistance. [ABSTRACT FROM AUTHOR]

Rapid sea-level rise between the Last Glacial Maximum (LGM) and the mid-Holocene transformed the Southeast Asian coastal landscape, but the impact on human demography remains unclear. Here, we create a paleogeographic map, focusing on sea-level changes during the period spanning the LGM to the present-day and infer the human population history in Southeast and South Asia using 763 high-coverage whole-genome sequencing datasets from 59 ethnic groups. We show that sea-level rise, in particular meltwater pulses 1 A (MWP1A, ~14,500–14,000 years ago) and 1B (MWP1B, ~11,500–11,000 years ago), reduced land area by over 50% since the LGM, resulting in segregation of local human populations. Following periods of rapid sea-level rises, population pressure drove the migration of Malaysian Negritos into South Asia. Integrated paleogeographic and population genomic analysis demonstrates the earliest documented instance of forced human migration driven by sea-level rise. Population genomic analyses and palaeogeographical modelling combine to help infer the ancient migration of humans into South Asia from Sundaland, driven by rapid sea level rises. [ABSTRACT FROM AUTHOR]

The great rivers that flow from the southern Tibetan Plateau (TP) affect billions of people in the downstream countries of Asia. Understanding of the hydrological variability of these rivers is still limited, however, because of the lack of long-term streamflow records. Tree-ring width chronologies from six sites are applied to reconstruct annual streamflow of the Salween River, the last remaining large free-flowing transboundary river draining the southern TP, and a critical water source for countries of Southeast Asia. Response function analysis shows that precipitation is the main factor limiting the radial growth of the sampled trees. Linear regression of annual (September–June) Salween River streamflow on the first principal component of tree-ring chronologies explains 53.4% of the streamflow variance, 1958–2011, and yields a reconstruction for the interval 1500–2011 CE. A tally of droughts and wet periods emphasizes the severity of droughts before the start of the gauged records, and a tendency toward wetter conditions in recent decades. Regional temperature is negatively associated with the reconstructed streamflow. Cold wet summers controlled by the Asian summer monsoon are responsible for an increasing trend in streamflow over the last decades. Reconstructed hydrological change is linked to the history of mainland Southeast Asia through the impact of water shortages on Burma society. In particular, prolonged periods of low flow of the Salween River coincide with the falls of the Toungoo Empires and the First Anglo-Burmese War. This tree-ring reconstruction provides a long-term perspective on hydrological changes in the Upper Salween River Basin that can give insight for sustainable water management on the TP and in Myanmar. [ABSTRACT FROM AUTHOR]

The complex climatic and geological history of Southeast Asia has been hypothesised to determine the most important aspects of the current phylogeographical structure and distribution of living organisms throughout the region. To test existing hypotheses, the genetic structure of the tire track eel, Mastacembelus favus, was investigated using 823 bp of mitochondrial DNA cytochrome b from 469 individuals from 51 localities encompassing its native range. The results classified all haplotypes into two major lineages, Lineage 1, which was further divided into Lineages 1a (lower Mekong, eastern Gulf of Thailand and Malay—Thai Peninsula), 1b (Banpakong River), 1c (Chao Phraya, Gulf of Thailand and Malay—Thai Peninsula) and 1d (Khlang Yai River), and Lineage 2, the upper reaches of the lower Mekong and the middle Mekong. Strong genetic discontinuities dated approximately 5 MYA were discovered in the Mekong with limited geographical overlap, suggesting a historically dissected drainage between two sections and species colonisation via different routes. The widespread Lineage 1 showed a strong signature of population expansion during the Pleistocene climate oscillation. Haplotype characteristics in the Malay—Thai Peninsula are hypothesised to result from postglacial dispersal from the Mekong and Chao Phraya through an extended Pleistocene drainage network. [ABSTRACT FROM AUTHOR]

Historical archaeology in Southeast Asia can be divided into two periods: the classic era of the Hindu and Buddhist civilizations, which began approximately 2,000 years ago, and the postclassic era, which began around A.D. 1400 with the expansion of Islam and Theravada Buddhism, followed by the arrival of European colonists in the 16th century. The use of 'historical archaeology' to refer to this 2,000-year-long period differs from the sense of the term used in Europe, South Africa, Australia, and North America, where historical archaeology is normally applied to the last 500 years. This essay describes the attitudes toward the transition from antiquity to the present from the perspective of archaeology in various parts of Southeast Asia. The main focus is on the perspective of local archaeologists, rather than those from outside the region. [ABSTRACT FROM AUTHOR]

Security has undoubtedly been a central and continuous feature of ASEAN since its establishment. While it has modified its basic thinking on security and adapted elements of the attendant principles, aims and ways of operation to meet changed circumstances, the level of consistency is still readily observable. Centrality of a different sort has been evident, too, during the post-Cold War period. ASEAN has consciously sought to position itself at the heart of the developing security architecture in both East Asia and the wider Asia-Pacific. The Association has been largely successful at limiting competition and preventing inter-state conflict among its members and at fostering a stable regional order in Southeast Asia (and an incipient one outside of the boundaries of Southeast Asia). Broadly speaking, this stability has been aided and abetted by the policies of the major external powers in whose interests it has been, up until now. The extent to which a stable regional order remains in the interests of the major powers will be one of the great questions for the next phase of ASEAN's life. [ABSTRACT FROM AUTHOR]

The vitality of ASEAN derives from its core. Until the mid 1990s, Indonesia, Malaysia, Singapore and Thailand provided the dynamism of ASEAN and their national leaders the regional leadership so necessary for the Association's existence. Entering its fifth decade, the Association seems posited at a 'mid-life crisis'. The ASEAN Charter has proposed bold ideas in community-building. Yet the 'loss' of a strong leadership impetus has cast a shadow of uncertainty over the extent to which ASEAN may reduce the gap between the richer and poorer nations of Southeast Asia. The extant two-tiered nature of ASEAN is problematic to its cohesion as each with its defining set of characteristics and views of regionalism. Can the more structured approach make up the leadership deficit and enable ASEAN to reconcile the division in its quest for regional unity? The prolonged Myanmar embarrassment seems to suggest an unconfident 'yes' at best. [ABSTRACT FROM AUTHOR]

This paper examines the structures of capitalism in Southeast Asia. Following the lead of Gordon Redding and others, it argues that parallel to varieties of capitalism elsewhere, there are distinctive features to the Southeast Asian business system, but that institutions play a relatively large role compared to firm specific resources or industry structures. Historically, with the exception of Thailand all the countries in the region are former colonies. All including Thailand share a distinctive style of nationalism, and partly as a result of this, all are governed by states that claim to be strong and lay wide claims but whose capacities are low. Typical features of the region, particularly the roles of large business groups and the Chinese minority, also can be interpreted as a result of this history. One of the outcomes of the analysis is an extension of the varieties of capitalism approach along the dimensions of state capacity and state direction, and of the approach to the internationalizing firm along the dimensions of dynamic capacity and control of subsidiaries. A further outcome is a questioning of the traditional picture of indigenous Southeast Asian business people as lacking in entrepreneurial skills, or more broadly of Southeast Asian nations as lacking in entrepreneurial values. Rather, the past history of these countries has resulted in a set of structures that militate against successful entrepreneurial activity. [ABSTRACT FROM AUTHOR]