231 research outputs found
Use of glacier river-fed estuary channels by juvenile Coho Salmon: transitional or rearing habitats?
Abstract Estuaries are among the most productive ecosystems in the world and provide important rearing environments for a variety of fish species. Though generally considered important transitional habitats for smolting salmon, little is known about the role that estuaries serve for rearing and the environmental conditions important for salmon. We illustrate how juvenile coho salmon Oncorhynchus kisutch use a glacial river-fed estuary based on examination of spatial and seasonal variability in patterns of abundance, fish size, age structure, condition, and local habitat use. Fish abundance was greater in deeper channels with cooler and less variable temperatures, and these habitats were consistently occupied throughout the season. Variability in channel depth and water temperature was negatively associated with fish abundance. Fish size was negatively related to site distance from the upper extent of the tidal influence, while fish condition did not relate to channel location within the estuary ecotone. Our work demonstrates the potential this glacially-fed estuary serves as both transitional and rearing habitat for juvenile coho salmon during smolt emigration to the ocean, and patterns of fish distribution within the estuary correspond to environmental conditions
Childbearing intentions in a low fertility context: the case of Romania
This paper applies the Theory of Planned Behaviour (TPB) to find out the predictors of fertility intentions in Romania, a low-fertility country. We analyse how attitudes, subjective norms and perceived behavioural control relate to the intention to have a child among childless individuals and one-child parents. Principal axis factor analysis confirms which items proposed by the Generation and Gender Survey (GGS 2005) act as valid and reliable measures of the suggested theoretical socio-psychological factors. Four parity-specific logistic regression models are applied to evaluate the relationship between the socio-psychological factors and childbearing intentions. Social pressure emerges as the most important aspect in fertility decision-making among childless individuals and one-child parents, and positive attitudes towards childbearing are a strong component in planning for a child. This paper also underlines the importance of the region-specific factors when studying childbearing intentions: planning for the second child significantly differs among the development regions, representing the cultural and socio-economic divisions of the Romanian territory
Religious socialisation and fertility: transition to third birth in the Netherlands
Although previous studies have demonstrated that religious people in Europe have larger families, the role played by religious socialisation in the context of contemporary fertility behaviour has not yet been analysed in detail. This contribution specifically looks at the interrelation between religious socialisation and current religiosity and their impact on the transition to the third child for Dutch women. It is based on data of the first wave of the Netherlands Kinship Panel Study (2002â2004) and uses event history analysis. The transitions to first, second and third birth are modelled jointly with a control for unobserved heterogeneity. The findings provide evidence for an impact of womenâs current church attendance as well as religious socialisation measured by their fathersâ religious affiliation, when they were teenagers. A religious family background remains influential even when a woman has stopped attending church. The effects of religious indicators strengthen over cohorts. Moreover, the combined religious make-up of the respondentâs parents also significantly determines the progression to the third child.Sâil est bien Ă©tabli que les croyants en Europe ont plus dâenfants que les autres, le rĂŽle de la socialisation religieuse dans le contexte de la fĂ©conditĂ© contemporaine nâa pas encore Ă©tĂ© analysĂ© Ă ce jour. Cette Ă©tude sâintĂ©resse au lien entre la socialisation religieuse et la religiositĂ© actuelle, et Ă leur impact sur la probabilitĂ© dâagrandissement de deux Ă trois enfants de la descendance des femmes nĂ©erlandaises. Les donnĂ©es exploitĂ©es sont celles de la premiĂšre vague du Panel NĂ©erlandais dâEtude de la ParentĂ© (the Netherlands Kinship Panel Study, 2002â2004). A lâaide des techniques de lâanalyse des biographies, les probabilitĂ©s dâagrandissement de rang 1, rang 2 et rang 3 ont Ă©tĂ© modĂ©lisĂ©es de façon conjointe, en contrĂŽlant lâhĂ©tĂ©rogĂ©nĂ©itĂ© non observĂ©e. Les rĂ©sultats mettent en Ă©vidence lâimpact de la frĂ©quentation actuelle de lâĂ©glise par les femmes et de leur socialisation religieuse, mesurĂ©e par lâappartenance religieuse de leur pĂšre quand elles Ă©taient adolescentes. Il apparaĂźt que la religiositĂ© du contexte familial exerce une influence, mĂȘme quand la femme ne frĂ©quente plus lâĂ©glise, et que les effets des indicateurs de pratique religieuse se renforcent dâune gĂ©nĂ©ration Ă lâautre. Enfin, lâappartenance religieuse conjointe des parents de la femme dĂ©termine significativement la probabilitĂ© dâavoir un troisiĂšme enfant
Home bitter home? Gender, living arrangements, and the exclusion from homeownership among older Europeans
Abstract Homeownership is the most important asset among the elderly in Europe, but very little is known about gender and living arrangement differences in this domain. This paper aims at exploring patterns of exclusion from homeownership among middle-aged and older Europeans from a gender perspective, and with a special focus on their household composition. The analysis is based on the fourth wave of the âSurvey of Health, Aging and Retirement in Europeâ and includes a sub-sample of about 56,000 individuals aged 50 or over, living in 16 European countries. We estimated a set of multinomial logit models to examine the probability of being either tenant or rent-free occupiers versus homeowners. Our findings show that women are generally more likely to be excluded from homeownership than men. Nevertheless, a closer look suggests that the gender gap in homeownership is essentially generated by compositional differences between men and women, with the most relevant factor being household type. Older women are almost as twice as likely as men to live alone, which is associatedâother things being equalâwith a particular low likelihood to be homeowners virtually in every European country
Expedition 382 Preliminary Report: Iceberg Alley and Subantarctic Ice and Ocean Dynamics
This is the final version. Available from International Ocean Discovery Program via the DOI in this record.âŻInternational Ocean Discovery Program (IODP) Expedition 382, Iceberg Alley and Subantarctic Ice and Ocean Dynamics, investigated the long-term climate history of Antarctica, seeking to understand how polar ice sheets responded to changes in insolation and atmospheric CO2 in the past and how ice sheet evolution influenced global sea level and vice versa. Five sites (U1534âU1538) were drilled east of the Drake Passage: two sites at 53.2°S at the northern edge of the Scotia Sea and three sites at 57.4°â59.4°S in the southern Scotia Sea. We recovered continuously deposited late Neogene sediment to reconstruct the past history and variability in Antarctic Ice Sheet (AIS) mass loss and associated changes in oceanic and atmospheric circulation. The sites from the southern Scotia Sea (Sites U1536âU1538) will be used to study the Neogene flux of icebergs through âIceberg Alley,â the main pathway along which icebergs calved from the mar- gin of the AIS travel as they move equatorward into the warmer wa- ters of the Antarctic Circumpolar Current (ACC). In particular, sediments from this area will allow us to assess the magnitude of iceberg flux during key times of AIS evolution, including the following: âą The middle Miocene glacial intensification of the East Antarctic Ice Sheet, âą The mid-Pliocene warm period, âą The late Pliocene glacial expansion of the West Antarctic Ice Sheet, âą The mid-Pleistocene transition (MPT), and âą The âwarm interglacialsâ and glacial terminations of the last 800 ky. We will use the geochemical provenance of iceberg-rafted detritus and other glacially eroded material to determine regional sources of AIS mass loss. We will also address interhemispheric phasing of ice sheet growth and decay, study the distribution and history of land-based versus marine-based ice sheets around the continent over time, and explore the links between AIS variability and global sea level. By comparing northâsouth variations across the Scotia Sea be- tween the Pirie Basin (Site U1538) and the Dove Basin (Sites U1536 and U1537), Expedition 382 will also deliver critical information on how climate changes in the Southern Ocean affect ocean circulation through the Drake Passage, meridional overturning in the region, water mass production, oceanâatmosphere CO2 transfer by wind- induced upwelling, sea ice variability, bottom water outflow from the Weddell Sea, Antarctic weathering inputs, and changes in oceanic and atmospheric fronts in the vicinity of the ACC. Comparing changes in dust proxy records between the Scotia Sea and Antarctic ice cores will also provide a detailed reconstruction of changes in the Southern Hemisphere westerlies on millennial and orbital timescales for the last 800 ky. Extending the ocean dust record beyond the last 800 ky will help to evaluate dust-climate couplings since the Pliocene, the potential role of dust in iron fertilization and atmospheric CO2 drawdown during glacials, and whether dust input to Antarctica played a role in the MPT. The principal scientific objective of Subantarctic Front Sites U1534 and U1535 at the northern limit of the Scotia Sea is to recon- struct and understand how ocean circulation and intermediate water formation responds to changes in climate with a special focus on the connectivity between the Atlantic and Pacific basins, the âcold water route.â The Subantarctic Front contourite drift, deposited between 400 and 2000 m water depth on the northern flank of an eastâwest trending trough off the Chilean continental shelf, is ideally situated to monitor millennial- to orbital-scale variability in the export of Antarctic Intermediate Water beneath the Subantarctic Front. During Expedition 382, we recovered continuously deposited sediments from this drift spanning the late Pleistocene (from ~0.78 Ma to recent) and from the late Pliocene (~3.1â2.6 Ma). These sites are expected to yield a wide array of paleoceanographic records that can be used to interpret past changes in the density structure of the Atlantic sector of the Southern Ocean, track migrations of the Sub- antarctic Front, and give insights into the role and evolution of the cold water route over significant climate episodes, including the following: âą The most recent warm interglacials of the late Pleistocene and âą The intensification of Northern Hemisphere glaciation.National Science Foundatio
Ancient marine sediment DNA reveals diatom transition in Antarctica
Antarctica is one of the most vulnerable regions to climate change on Earth and studying the past and present responses of this polar marine ecosystem to environmental change is a matter of urgency. Sedimentary ancient DNA (sedaDNA) analysis can provide such insights into past ecosystem-wide changes. Here we present authenticated (through extensive contamination control and sedaDNA damage analysis) metagenomic marine eukaryote sedaDNA from the Scotia Sea region acquired during IODP Expedition 382. We also provide a marine eukaryote sedaDNA record of ~1 Mio. years and diatom and chlorophyte sedaDNA dating back to ~540 ka (using taxonomic marker genes SSU, LSU, psbO). We ïŹnd evidence of warm phases being associated with high relative diatom abundance, and a marked transition from diatoms comprising <10% of all eukaryotes prior to ~14.5 ka, to ~50% after this time, i.e., following Meltwater Pulse 1A, alongside a composition change from sea-ice to openocean species. Our study demonstrates that sedaDNA tools can be expanded to hundreds of thousands of years, opening the pathway to the study of ecosystem-wide marine shifts and paleo-productivity phases throughout multiple glacial-interglacial cycles.Antarctica is one of the most vulnerable regions to climate change on Earth and studying the past and present responses of this polar marine ecosystem to environmental change is a matter of urgency. Sedimentary ancient DNA (sedaDNA) analysis can provide such insights into past ecosystem-wide changes. Here we present authenticated (through extensive contamination control and sedaDNA damage analysis) metagenomic marine eukaryote sedaDNA from the Scotia Sea region acquired during IODP Expedition 382. We also provide a marine eukaryote sedaDNA record of ~1 Mio. years and diatom and chlorophyte sedaDNA dating back to ~540 ka (using taxonomic marker genes SSU, LSU, psbO). We find evidence of warm phases being associated with high relative diatom abundance, and a marked transition from diatoms comprising <10% of all eukaryotes prior to ~14.5 ka, to ~50% after this time, i.e., following Meltwater Pulse 1A, alongside a composition change from sea-ice to open-ocean species. Our study demonstrates that sedaDNA tools can be expanded to hundreds of thousands of years, opening the pathway to the study of ecosystem-wide marine shifts and paleo-productivity phases throughout multiple glacial-interglacial cycles.Postprin
How are time-dependent childbearing intentions realized? Realization, postponement, abandonment, bringing forward
Our study aims to identify factors that facilitate or inhibit the realization of fertility intentions. The analysis uses data collected in the first two waves of a Hungarian longitudinal survey. Fertility intentions recorded at the first wave pertain to the subsequent 3-year period, just similar to the behavior variable measuring the realization of intentions, i.e., a birth within the 3-year period in question. For this analysis, we used the respondentsâ demographic, socio-structural, and orientational traits recorded at the first interview. Our findings show that age, parity, and partnership play a determining role in the realization of fertility intentions, but employment status, religious affiliation, and overall life satisfaction all exhibit significant effects. A marked gender difference was detected not only with regard to employment status but in the area of values and orientations as well.Lâobjectif de notre Ă©tude est dâidentifier les facteurs qui facilitent ou inhibent la rĂ©alisation des intentions de fĂ©conditĂ©. Lâanalyse sâappuie sur les deux premiĂšres vagues dâune enquĂȘte longitudinale menĂ©e en Hongrie. Les intentions de fĂ©conditĂ© recueillies dans le cadre de la premiĂšre vague concernent la pĂ©riode des trois annĂ©es Ă venir, de la mĂȘme façon que la variable de comportement mesurant la rĂ©alisation des intentions, Ă savoir, une naissance survenue au cours de cette mĂȘme pĂ©riode. Les caractĂ©ristiques dĂ©mographiques et socio-structurelles, de mĂȘme que certaines dispositions personnelles recueillies lors du premier entretien ont Ă©tĂ© utilisĂ©es dans lâanalyse. Nos rĂ©sultats indiquent quâĂ la fois lâĂąge, la paritĂ©, et la situation de couple jouent un rĂŽle capital dans la rĂ©alisation des intentions et aussi que la situation dâemploi, lâappartenance religieuse et le niveau de satisfaction par rapport Ă la vie exercent une influence significative. Une diffĂ©rence prononcĂ©e entre hommes et femmes est mise en Ă©vidence en matiĂšre de situation dâemploi et Ă©galement dans le domaine des valeurs et des dispositions personnelles
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