746 research outputs found
Controversy in the Management of Cholangitis Secondary to Hydatid Daughter Cysts
A 36 year old Cypriot woman, resident in the U.K. since the age of three years, presented with pyrexia,
jaundice and upper abdominal pain. On ultrasound examination the biliary tree was dilated, contained
sludge and a cystic lesion was present in the liver. An endoscopic cholangiogram showed multiple filling
defects in the bile duct which were not felt to be removable endoscopically and a nasobiliary drain was
therefore inserted. On resolution of the cholangitis with drainage and antibiotics a laparotomy was
performed. The right lobe of the liver was largely replaced by a multiloculated cyst and the bile duct
contained multiple hydatid daughter cysts. A right hepatectomy was performed with t-tube drainage of
the evacuated bile duct. She made an uneventful recovery and has had no problems on subsequent
follow up. Histology confirmed an intrabiliary rupture of a hydatid liver cyst
Integration of technologies for understanding the functional relationship between reef habitat and fish growth and production
Functional linkage between reef habitat quality and fish growth and production has remained elusive. Most current research is focused on correlative relationships between a general habitat type and presence/absence of a species,
an index of species abundance, or species diversity. Such descriptive information largely ignores how reef attributes
regulate reef fish abundance (density-dependent habitat selection), trophic interactions, and physiological performance (growth and condition). To determine the
functional relationship between habitat quality, fish abundance, trophic interactions, and physiological performance, we are using an experimental reef system in
the northeastern Gulf of Mexico where we apply advanced sensor and biochemical technologies. Our study site controls for reef attributes (size, cavity space, and reef
mosaics) and focuses on the processes that regulate gag grouper (Mycteroperca microlepis) abundance, behavior and performance (growth and condition), and the availability of their pelagic prey. We combine mobile and fixed-active (fisheries) acoustics, passive acoustics, video cameras,
and advanced biochemical techniques. Fisheries acoustics quantifies the abundance of pelagic prey fishes associated
with the reefs and their behavior. Passive acoustics and video allow direct observation of gag and prey fish behavior and the acoustic environment, and provide a
direct visual for the interpretation of fixed fisheries acoustics measurements. New application of biochemical techniques, such as Electron Transport System (ETS) assay,
allow the in situ measurement of metabolic expenditure of gag and relates this back to reef attributes, gag behavior, and prey fish availability. Here, we provide an overview of our integrated technological approach for understanding and quantifying the functional relationship between reef habitat quality and one element of production – gag grouper growth on shallow coastal reefs
Techno-economic analysis of expander-based configurations for natural gas liquefaction
The use of liquefied natural gas (LNG) as a marine fuel is rapidly growing because of the possible economic
advantages over conventional fuels and stricter environmental regulations. Production of LNG is energy intensive
because of the required temperature level of around -160\ub0C. Three main types of refrigeration cycles
have been developed. The present work focuses on the comparison of six expander-based configurations,
which in spite of the higher power consumption, are more compact, flexible and easier to operate. They are
optimised from a thermodynamic perspective: the exergetic efficiency is found to range between 17 % and 33
% for a specific power consumption down to 1340 kJ/kg.
Multi-objective optimisations are performed to simultaneously minimise the net power consumption and the
heat transfer conductance as an indicator of the required heat transfer area. The latter ranges between 50
kW/K and 300 kW/K.
A trade-off between power consumption and heat transfer area is found, which justifies a further economic
analysis. A simplified economic analysis is set based on a discounted cash flow model. The unitary profit
ranges between 0.5 and 0.9 DKK/kg of produced LNG. The most profitable expander-based configuration is
the dual-refrigerant cycle with nitrogen in the bottoming refrigeration cycle. Finally, the influence of the cost
correlations on the economic outcome is assessed: the compressors represent the major costs, which leads
to the coincidence of the thermodynamic and economic optima
The interplay between the level of voluntary participation and supervisor support on trainee motivation and transfer
International audienceAbstract There have been conflicting findings about whether mandatory versus voluntary training leads to more positive training outcomes. We propose moving away from a dichotomous distinction to a more dynamic participation approach to better elucidate theoretical differences relating to self‐determination theory. A sample of 311 trainees from eight companies participated in a variety of open skill (e.g., leadership) training programs. Results indicated that higher levels of voluntary participation were positively related to trainees' transfer motivation and training transfer. We also found that the level of voluntary participation moderates the relationship between supervisor support and both motivation to transfer and training transfer. Supervisor support facilitates trainee motivation and transfer to a larger extent when participation is less voluntary. Future training should be framed and promoted to increase employee motivation to voluntarily participate, especially for employees with less supervisor support
Development of the legitimacy threshold scale
A consensus in the literature supports the premise that legitimacy attainment facilitates favorable judgments from key stakeholders regarding the acceptability, appropriateness and worthiness of entrepreneurs and their efforts in emerging ventures. However, although legitimacy attainment is a milestone that emerging ventures strive to reach, as researchers we do not yet have a measure that examines whether a firm is operating pre- versus post-legitimacy. Accordingly, we develop the legitimacy threshold scale (LTS) that will facilitate the assessment of activities performed pre- and post-legitimacy in emerging ventures
The Effect of Dissolved Humic Acids on Aluminosilicate Formation and Associated Carbon Sequestration
Allophane and imogolite neogenesis in soils may occur in the presence of organic matter. To understand this process under conditions relevant to soils, the influence of dissolved organic carbon (DOC) as humic acid (HA), on aluminosilicate formation was studied at 25◦C, pH 6, and low-DOC concentrations. For solutions with initial Al/Si ratios of 1–2.1, and 0–6mg/L DOC, precipitates recovered after 20h had Al/Si ratios of 2.2–2.7. The formation of allophane, imogolite-like material, and aluminosilicate gel was confirmed by XRD, FTIR, and NMR. The effect of DOC was to produce a small, but systematic increase in imogolite-like Si in the precipitate, and a decrease in the formation of aluminosilicate gel. Results suggest that the presence of DOC as HA slows the otherwise rapid polymerization of Al and Si at low temperature, and may also promote the formation of imogolite. The high C content of these precipitates indicates that this process may facilitate the sequestration of organic matter, slowing C cycling in soils
Prevalence, trajectories, and determinants of television viewing time in an ethnically diverse sample of young children from the UK
BACKGROUND: Excessive screen viewing in early childhood is associated with poor physical and psycho-social health and poor cognitive development. This study aimed to understand the prevalence, trajectory and determinants of television viewing time in early childhood to inform intervention development. METHODS: In this prospective longitudinal study, mothers of 1558 children (589 white British, 757 Pakistani heritage, 212 other ethnicities) completed questionnaires when their children were approximately 6, 12, 18, 24 and 36 months old. Mothers answered questions about their own and their child's TV-time. TV-time trajectories were estimated by linear longitudinal multilevel modeling, potential determinants were considered in models. RESULTS: The modelled trajectory estimated that 75% of children aged 12 months exceeded guidelines of zero screen-time. At 12 months of age an accelerated increase in TV-time was observed (2 h/day by 30 months old). For every hour of mothers' TV-time and every hour the TV was on in the home, children's TV-time was 8 min and 1 min higher respectively at 6 months old (P < 0.05), and 15 min and 3 min higher respectively at 36 months old (P < 0.05). Children whose mothers did not agree that it was important their child did not watch too much TV, had 17 min more TV-time than their counterparts (P < 0.05). Children of first time mothers had 6 min more TV-time (P < 0.05). At 12 months of age, children of mothers experiencing stress watched 8 min more TV (P < 0.05). By 36 months, children of Pakistani heritage mothers had 22 min more TV-time than those of white British mothers (P < 0.05), and an additional 35 min of TV-time if their mother was not born in the UK (P < 0.05). CONCLUSIONS: High levels of TV-time were prevalent. Intervention developers should consider targeting interventions before 12 months of age. Modifiable determinants included mothers' own TV-time, the time the television is on in the home and mothers' attitude towards child TV-time. These behaviours may be key components to address in interventions for parents. Mothers experiencing stress, first time mothers, and Pakistani heritage mothers (particularly those born outside of the UK), may be priority groups for intervention
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