940 research outputs found
Parental income and children’s smoking behaviour: evidence from the british household panel survey
Does money matter? When investigating health behaviour, research often finds a strong positive association between income and healthy behaviour. This could however be due to individual characteristics that determine both income and health investment and is not necessarily due to the role of money per se. In this study we look at this relationship over the generations by studying the association between parental income and children’s prevalence to smoke in Britain using data from the British Household Panel Survey and British Youth Survey. We find an inverse relation between parental income and children’s smoking prevalence, but when looking at within household changes by comparing sibling’s smoking status differences at the same age, we find instead a positive effect. This indicates that within household increases in income lead to an increased probability of smoking of a younger child
Is There a Heat or Eat Trade-off in the UK?
We merge detailed household level expenditure data from older households with historical local weather information. We then test for a heat or eat trade off: do households cut back on food spending to finance the additional cost of keeping warm during cold shocks? For households who cannot smooth consumption over time, cold weather shocks are equivalent to income shocks. We find evidence that the poorest of older households are unable to smooth spending over the worst temperature shocks. Statistically significant reductions in food spending are observed in response to winter temperatures two or more standard deviations colder than expected (which occur about one winter month in forty) and reductions in food expenditure are considerably larger in poorer households.
Functional genomics of a symbiotic community : shared traits in the olive fruit fly gut microbiota
The olive fruit fly Bactrocera oleae is a major pest of olives worldwide and houses a specialized gut microbiota dominated by the obligate symbiont “Candidatus Erwinia dacicola”. Ca. E. dacicola is thought to supplement dietary nitrogen to the host, with only indirect evidence for this hypothesis so far. Here, we sought to investigate the contribution of the symbiosis to insect fitness and explore the ecology of the insect gut. For this purpose, we examined the composition of bacterial communities associated with Cretan olive fruit fly populations, and inspected several genomes and one transcriptome assembly. We identified, and reconstructed the genome of, a novel component of the gut microbiota, Tatumella sp. TA1, which is stably associated with Mediterranean olive fruit fly populations. We also reconstructed a number of pathways related to nitrogen assimilation and interactions with the host. The results show that, despite variation in taxa composition of the gut microbial community, core functions related to the symbiosis are maintained. Functional redundancy between different microbial taxa was observed for genes involved in urea hydrolysis. The latter is encoded in the obligate symbiont genome by a conserved urease operon, likely acquired by horizontal gene transfer, based on phylogenetic evidence. A potential underlying mechanism is the action of mobile elements, especially abundant in the Ca. E. dacicola genome. This finding, along with the identification, in the studied genomes, of extracellular surface structure components that may mediate interactions within the gut community, suggest that ongoing and past genetic exchanges between microbes may have shaped the symbiosis
Polarization-squeezed light formation in a medium with electronic Kerr nonlinearity
We analyze the formation of polarization-squeezed light in a medium with
electronic Kerr nonlinearity. Quantum Stokes parameters are considered and the
spectra of their quantum fluctuations are investigated. It is established that
the frequency at which the suppression of quantum fluctuations is the greatest
can be controlled by adjusting the linear phase difference between pulses. We
shown that by varying the intensity or the nonlinear phase shift per photon for
one pulse, one can effectively control the suppression of quantum fluctuations
of the quantum Stokes parameters.Comment: final version, RevTeX, 10 pages, 5 eps figure
Large-scale and significant expression from pseudogenes in Sodalis glossinidius – a facultative bacterial endosymbiont
The majority of bacterial genomes have high coding efficiencies, but there are some genomes of intracellular bacteria that have low gene density. The genome of the endosymbiont Sodalis glossinidius contains almost 50 % pseudogenes containing mutations that putatively silence them at the genomic level. We have applied multiple ‘omic’ strategies, combining Illumina and Pacific Biosciences Single-Molecule Real-Time DNA sequencing and annotation, stranded RNA sequencing and proteome analysis to better understand the transcriptional and translational landscape of Sodalis pseudogenes, and potential mechanisms for their control. Between 53 and 74 % of the Sodalis transcriptome remains active in cell-free culture. The mean sense transcription from coding domain sequences (CDSs) is four times greater than that from pseudogenes. Comparative genomic analysis of six Illumina-sequenced Sodalis isolates from different host Glossina species shows pseudogenes make up ~40 % of the 2729 genes in the core genome, suggesting that they are stable and/or that Sodalis is a recent introduction across the genus Glossina as a facultative symbiont. These data shed further light on the importance of transcriptional and translational control in deciphering host–microbe interactions. The combination of genomics, transcriptomics and proteomics gives a multidimensional perspective for studying prokaryotic genomes with a view to elucidating evolutionary adaptation to novel environmental niches
Variation in the structure and function of invertebrate-associated bacterial communities
Microorganisms are intricately involved in the ecology of many insects, often contributing to host fitness and forming evolutionarily stable associations. The interactions between hosts and microbes can significantly alter their evolutionary trajectories, enabling them to adapt to novel environmental conditions. In this thesis I have examined how host ecology can shape the interactions of bacteria with insects of agricultural and epidemiological importance. I have described the bacterial communities associated with Bactrocera oleae (the olive fruit fly) and generated draft genome sequences for several members of the gut microbiota, including the symbiotic bacterium “Candidatus Erwinia dacicola”. Comparative genomic analyses indicate that Ca. E. dacicola and a novel facultative bacterium Tatumella TA1 may perform key nutritional functions for the host, including the synthesis of essential amino acids and ammonia assimilation from host nitrogenous waste products. Tatumella TA1 is consistently associated with all life stages of populations collected in Israel and Crete at low relative abundance, and encodes large adhesion proteins that may assist in attachment to the host epithelium or other members of the microbiota in the B. oleae gut. I have also examined the variation in frequency and relative abundance of facultative microbes that infect several Glossina spp. (the tsetse fly): the sole vector of African trypanosomes in Sub-Saharan Africa. In addition to three vertically transmitted endosymbionts (Wigglesworthia, Sodalis, and Wolbachia), tsetse flies are infected with two additional potential reproductive manipulators: Spiroplasma and Rickettsia, and a novel strain of Klebsiella. The draft genomes generated for these taxa over the course of this thesis provide the opportunity for future studies in to their role in host biology and how community interactions can shape the transmission and evolutionary dynamics of host-associated microbes
Variation in the structure and function of invertebrate-associated bacterial communities
Microorganisms are intricately involved in the ecology of many insects, often contributing to host fitness and forming evolutionarily stable associations. The interactions between hosts and microbes can significantly alter their evolutionary trajectories, enabling them to adapt to novel environmental conditions. In this thesis I have examined how host ecology can shape the interactions of bacteria with insects of agricultural and epidemiological importance. I have described the bacterial communities associated with Bactrocera oleae (the olive fruit fly) and generated draft genome sequences for several members of the gut microbiota, including the symbiotic bacterium “Candidatus Erwinia dacicola”. Comparative genomic analyses indicate that Ca. E. dacicola and a novel facultative bacterium Tatumella TA1 may perform key nutritional functions for the host, including the synthesis of essential amino acids and ammonia assimilation from host nitrogenous waste products. Tatumella TA1 is consistently associated with all life stages of populations collected in Israel and Crete at low relative abundance, and encodes large adhesion proteins that may assist in attachment to the host epithelium or other members of the microbiota in the B. oleae gut. I have also examined the variation in frequency and relative abundance of facultative microbes that infect several Glossina spp. (the tsetse fly): the sole vector of African trypanosomes in Sub-Saharan Africa. In addition to three vertically transmitted endosymbionts (Wigglesworthia, Sodalis, and Wolbachia), tsetse flies are infected with two additional potential reproductive manipulators: Spiroplasma and Rickettsia, and a novel strain of Klebsiella. The draft genomes generated for these taxa over the course of this thesis provide the opportunity for future studies in to their role in host biology and how community interactions can shape the transmission and evolutionary dynamics of host-associated microbes
Injury Type, Injury Severity, and Repeat Occurrence of Alcohol-Related Trauma in Adolescents
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66113/1/j.1530-0277.1994.tb00011.x.pd
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