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First Introduction (first + introduction)
Selected AbstractsIntroduction of solids and formula to breastfed infants: a longitudinal prospective study in Uppsala, SwedenACTA PAEDIATRICA, Issue 5 2001A Hörnell The introduction of solids and formula was studied among 506 breastfed infants in Uppsala, Sweden, based on daily recordings during the first year. The mothers had previously breastfed at least 1 infant for at least 4 mo. Thirty-four per cent of the infants were introduced to solids before the age of 4 mo (4,6 mo is recommended in Sweden). Accustoming the infants to solids was a lengthy process. Life-table analyses showed a median duration of 28 d from the first introduction of solids to consumption of >10 ml daily, and 46 d before the infants ate 100 ml of solids in 1 d for the first time. These durations were longer the younger the infant was at the introduction of solids. Thirty-two per cent of infants given formula consumed 100 ml the first time it was given, and 49% did so within 1 wk, regardless of infant age. Conclusion: Parents and healthcare personnel need to be aware that accustoming breastfed infants to solid food is a lengthy process, and that there is a strong age effect on this duration. It is also important to consider what consequences the (usually) more abrupt introduction of formula might have on breastfeeding. [source] Time to establishment success for introduced signal crayfish in Sweden , a statistical evaluation when success is partially knownJOURNAL OF APPLIED ECOLOGY, Issue 5 2010Ullrika Sahlin Summary 1.,The signal crayfish Pacifastacus leniusculus is an invasive species in Sweden, threatening the red-listed nobel crayfish Astacus astacus through spreading the crayfish plague. Time-to-event models can handle censored data on such introduced populations for which the state (successful or not) is only partially known at the last observation, but even though data on introduced populations most often are censored, this type of model is usually not used for likelihood-based inference and predictions of the dynamics of establishing populations. 2.,We specified and fitted a probabilistic time-to-event model to be used to predict the time to successful establishment of signal crayfish populations introduced into Sweden. Important covariates of establishment success were found by the methods of ,model averaging' and ,hierarchical partitioning', considering model uncertainty and multi-colinearity, respectively. 3.,The hazard function that received the highest evidence based on the empirical data showed that the chances of establishment were highest in the time periods immediately following the first introduction. The model predicts establishment success to be <50% within 5 years after first introduction over the current distributional range of signal crayfish in Sweden today. 4.,Among covariates related to temperature, fish species and physical properties of the habitat, the length of the growing season was the most important and consistent covariate of establishment success. We found that establishment success of signal crayfish is expected to increase with the number of days when growth is possible, and decrease with the number of days with extremely high temperatures, which can be seen to approximate conditions of stress. 5.,Synthesis and applications. The results demonstrate lower establishment success of signal crayfish further north in Sweden, which may decrease the incentives of additional illegal introductions that may threaten the red-listed noble crayfish Astacus astacus. We provide a fully probabilistic statistical evaluation that quantifies uncertainty in the duration of the establishment stage that is useful for management decisions of invasive species. The combination of model averaging and hierarchical partitioning provides a comprehensive method to address multi-colinearity common to retrospective data on establishment success of invasive species. [source] Simple sample transfer technique by internally expanded desorptive flow for needle trap devicesJOURNAL OF SEPARATION SCIENCE, JSS, Issue 12 2008In-Yong Eom Abstract Needle trap devices (NTDs) are improving in simplicity and usefulness for sampling volatile organic compounds (VOCs) since their first introduction in early 2000s. Three different sample transfer methods have been reported for NTDs to date. All methods use thermal desorption and simultaneously provide desorptive flow to transfer desorbed VOCs into a GC separation column. For NTDs having ,side holes', GC carrier gas enters a ,side hole' and passes through sorbent particles to carry desorbed VOCs, while for NTD not having a ,side hole', clean air as desorptive flow can be provided through a needle head by a air tight syringe to sweep out desorbed VOCs or water vapor has been reported recently to be used as desorptive flow. We report here a new simple sample transfer technique for NTDs, in which no side holes and an external desorptive flow are required. When an NTD enriched by a mixture of benzene, toluene, ethylbenzene, and xylene (BTEX) or n -alkane mixture (C6,C15) is exposed to the hot zone of GC injector, the expanding air above the packed sorbent transfers the desorbed compounds from the sorbent to the GC column. This internal air expansion results in clean and sharp desorption profiles for BTEX and n -alkane mixture with no carryover. The effect of desorption temperature, desorption time, and overhead volumes was studied. Decane having vapor pressure of ,1 Torr at 20°C showed ,1% carryover at the moderate thermal desorption condition (0.5 min at 250°C). [source] The origins, early development and status of Bourdieu's concept of ,cultural capital'THE BRITISH JOURNAL OF SOCIOLOGY, Issue 1 2005Derek Robbins Abstract The paper examines the context of the first introduction of the concept of ,cultural capital' in the sociology of education analyses undertaken in the early 1960s and published by Bourdieu in collaboration with Jean-Claude Passeron in ,Les étudiants et leurs études' (1964a) and Les Héritiers (1964b). It first considers the cultural contexts within which Bourdieu's thinking about culture originated , both in relation to his social origins and in relation to his intellectual training. It then examines the extent to which Bourdieu's early anthropological research in Algeria was influenced by his knowledge of American acculturation theory. It concludes that Bourdieu sought to use acculturation theory in a distinctive way , one which he articulated more confidently as he explored the relationship between agency and structural explanation in the late 1960s and early 1970s. The specific educational researches which stimulated the articulation of the concept of ,linguistic' or ,cultural' capital belonged to the period in which Bourdieu was only just beginning to refine his post-structuralist philosophy of social scientific explanation. To use these concepts now involves deploying them reflexively in accordance with Bourdieu's later thinking rather than at face value as they were first developed during the period in which he and Passeron were ,apprentice' researchers. [source] Fish movements: the introduction pathway for topmouth gudgeon Pseudorasbora parva and other non-native fishes in the UKAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 3 2010G. H. Copp Abstract 1.The contamination of fish consignments (for stocking or aquaculture) is a major pathway by which non-native organisms, including fish, are introduced to new areas. One of the best examples of this is the topmouth gudgeon Pseudorasbora parva, which was accidentally imported into Romania and then throughout Europe in consignments of Asian carp species. 2.The introduction and spread of topmouth gudgeon in the UK has been linked to imports and movements of the ornamental variety (golden orfe) of ide Leuciscus idus. To examine this hypothesis, relationships between authorized movements of both native and non-native fish species (in particular ide) and the occurrence in England of topmouth gudgeon were tested at the 10×10,km scale. 3.Topmouth gudgeon occurrence in the wild was significantly correlated with the trajectories of movements of ornamental fish species (ide/orfe, sunbleak Leucaspius delineatus) as well as a few non-ornamental fish species (European catfish Silurus glanis, Atlantic salmon Salmo salar and grass carp Ctenopharyngodon idella). 4.These results highlight the mechanism by which non-native fish species disperse from the point of first introduction, and especially that movements of fish within the country represent an important mechanism for accidental introductions of non-native species. © Crown copyright 2010. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd. [source] | ||||||||||