title: Migration, household composition and child welfare in rural Northeast Thailand

authors: Cameron, Michael Patrick

subjects: migration

abstract: In many developing countries, the composition of rural households is influenced by the migration of adult household members to urban locations in search of employment. Children may be left in the care of their mother alone, or in the care of grandparents when both parents have migrated. Using representative data from a household survey conducted in rural Northeast Thailand in 2003, this paper investigates whether household composition has any effect on the welfare of children, as measured by anthropometric measurements including height-for-age, weight-for-age, and weight-for-height. Our findings suggest that household types other than nuclear families result in some significantly worse child nutritional outcomes. The implication is that governments should protect the welfare of the children of migrants, either through targeted programs or through increased opportunities for employment in rural areas.

text: Migration, household composition and child welfare in rural Northeast Thailand In many developing countries, the composition of rural households is influenced by the migration of adult household members to urban locations in search of employment. Children may be left in the care of their mother alone, or in the care of grandparents when both parents have migrated. Using representative data from a household survey conducted in rural Northeast Thailand in 2003, this paper investigates whether household composition has any effect on the welfare of children, as measured by anthropometric measurements including height-for-age, weight-for-age, and weight-for-height. Our findings suggest that household types other than nuclear families result in some significantly worse child nutritional outcomes. The implication is that governments should protect the welfare of the children of migrants, either through targeted programs or through increased opportunities for employment in rural areas.

year: 2005-11

title: Historical biogeography of the Gondwanan freshwater genus Boeckella (Crustacea): Timing and modes of speciation in the Southern Hemisphere

authors: Maturana, Claudia S.

subjects: Science & Technology

abstract: Aim
We investigated evolutionary relationships and biogeographical patterns within the genus Boeckella to evaluate (1) whether its current widespread distribution in the Southern Hemisphere is due to recent long-distance dispersal or long-term diversification; and (2) the age and origin of sub-Antarctic and Antarctic Boeckella species, with particular focus on the most widely distributed species: Boeckella poppei.

Location
South America, sub-Antarctic islands, maritime Antarctica, continental Antarctica and Australasia.

Methods
To reconstruct phylogenetic patterns of Boeckella, we used molecular sequence data collected from 12 regions and applied Bayesian and Maximum Likelihood analyses using multiple loci. We also estimated divergence times and reconstructed ancestral ranges using two different models of species evolution.

Results
Phylogenetic analyses and divergence time estimates suggested that Boeckella originated on the Gondwanan supercontinent and initially split into two main clades during the late Cretaceous (ca. 80 Ma). The first clade diversified in Australasia, and the second clade is currently distributed in South America, various sub-Antarctic islands and Antarctica. Dispersal from South America to the Kerguelen and Crozet archipelagos occurred during the Eocene/Oligocene (B. vallentini) and in the late Pliocene (B. brevicaudata), while South Georgia and the maritime Antarctic were likely colonized during the late Pleistocene (B. poppei).

Main conclusions
Boeckella has a Gondwanan origin, with further diversifications after the physical separation of the continental landmasses. Extant populations of Boeckella from the Scotia Arc islands and Antarctic Peninsula originated from South America during the Pleistocene, suggesting that original Antarctic Gondwanan lineages did not survive repeated glacial cycles during the Quaternary ice ages. A continuous decline in the species accumulation rate is apparent within the genus as the early Eocene, suggesting that Boeckella diversification may have decreased due to progressive cooling throughout the Cenozoic era.

text: Historical biogeography of the Gondwanan freshwater genus Boeckella (Crustacea): Timing and modes of speciation in the Southern Hemisphere Aim
We investigated evolutionary relationships and biogeographical patterns within the genus Boeckella to evaluate (1) whether its current widespread distribution in the Southern Hemisphere is due to recent long-distance dispersal or long-term diversification; and (2) the age and origin of sub-Antarctic and Antarctic Boeckella species, with particular focus on the most widely distributed species: Boeckella poppei.

Location
South America, sub-Antarctic islands, maritime Antarctica, continental Antarctica and Australasia.

Methods
To reconstruct phylogenetic patterns of Boeckella, we used molecular sequence data collected from 12 regions and applied Bayesian and Maximum Likelihood analyses using multiple loci. We also estimated divergence times and reconstructed ancestral ranges using two different models of species evolution.

Results
Phylogenetic analyses and divergence time estimates suggested that Boeckella originated on the Gondwanan supercontinent and initially split into two main clades during the late Cretaceous (ca. 80 Ma). The first clade diversified in Australasia, and the second clade is currently distributed in South America, various sub-Antarctic islands and Antarctica. Dispersal from South America to the Kerguelen and Crozet archipelagos occurred during the Eocene/Oligocene (B. vallentini) and in the late Pliocene (B. brevicaudata), while South Georgia and the maritime Antarctic were likely colonized during the late Pleistocene (B. poppei).

Main conclusions
Boeckella has a Gondwanan origin, with further diversifications after the physical separation of the continental landmasses. Extant populations of Boeckella from the Scotia Arc islands and Antarctic Peninsula originated from South America during the Pleistocene, suggesting that original Antarctic Gondwanan lineages did not survive repeated glacial cycles during the Quaternary ice ages. A continuous decline in the species accumulation rate is apparent within the genus as the early Eocene, suggesting that Boeckella diversification may have decreased due to progressive cooling throughout the Cenozoic era.

year: 2021-09-14

title: Tīaho mai

authors: Maxwell, Te Kahautu

abstract: Waiata ā Ringa (action song). Lyrics composed by Te Kahautu Maxwell. Performed by Ōpōtiki Mai Tawhiti (Kapa Haka group)

text: Tīaho mai Waiata ā Ringa (action song). Lyrics composed by Te Kahautu Maxwell. Performed by Ōpōtiki Mai Tawhiti (Kapa Haka group)

year: 2024