4,193 research outputs found
Mapping a Continental Shelf and Slope in the 1990s: A Tale of Three Multibeams
Increasing societal pressures on the U.S. continental shelves adjacent to dense population centers have brought to light the lack of accurate base maps in these areas. Existing bathymetric maps and random sidescan sonar surveys are either not accurate enough or do not provide the coverage necessary to make policy decisions. Until the mid 1990s, it was not financially prudent nor technically efficient to map the shallow shelves. However, the availability of high-resolution multibeam mapping systems now allow efficient and accurate mapping of the continental margins. In 1996 the U.S. Geological Survey began a large-scale seafloor mapping campaign on the continental shelf and slope adjacent to Los Angeles, CA. The first survey used a Kongsberg Simrad EM1000 (95 kHz). The survey continued in 1998 by mapping the slope and proximal basins from Newport to Long Beach, CA, using a Kongsberg Simrad EM300 (30 kHz). The area was completed in May 1999 by mapping the entire shelf adjacent to Long Beach, CA using an EM3000D (a dual-headed 300-kHz system). The mapping used both INS from the vehicle motion sensor and DGPS to provide position accuracies of ~1 m. All the data were processed in the field in near realtime using software developed at the Univ. of New Brunswick. Because of the different systems used and the range of water depths, the spatial resolution of the processed data varies from \u3c0.5 m on the inner shelf to 8 m on the basin floors.
Perspective overviews of backscatter draped over bathymetry reveals a host of geological features unknown to exist in this area. These features include shallow, linear gullys, barchan dunes, small-scale bedforms in shallow troughs, major canyon system complexes, large- and smallscale mass movements, faults, and large areas of outcrop. The effects on sediment transport of man-made features, such as sewer outfall pipes and dredge-disposal fields, are clearly delineated on the new maps. The maps provide the fundamental base maps for studies as varied as those involving benthic habitats, marine disposal sites, sediment transport, and tectonic ma
Cell patterning on photolithographically defined parylene-C:SiO2 substrates
Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain central aspects of cellular physiology. To easily combine cell patterning with Multi-Electrode Arrays (MEAs) and silicon-based ‘lab on a chip’ technologies, a microfabrication-compatible protocol is required. We describe a method that utilizes deposition of the polymer parylene-C on SiO(2 )wafers. Photolithography enables accurate and reliable patterning of parylene-C at micron-level resolution. Subsequent activation by immersion in fetal bovine serum (or another specific activation solution) results in a substrate in which cultured cells adhere to, or are repulsed by, parylene or SiO(2) regions respectively. This technique has allowed patterning of a broad range of cell types (including primary murine hippocampal cells, HEK 293 cell line, human neuron-like teratocarcinoma cell line, primary murine cerebellar granule cells, and primary human glioma-derived stem-like cells). Interestingly, however, the platform is not universal; reflecting the importance of cell-specific adhesion molecules. This cell patterning process is cost effective, reliable, and importantly can be incorporated into standard microfabrication (chip manufacturing) protocols, paving the way for integration of microelectronic technology
Exploring the health and service utilisation of general practice patients with a history of adverse childhood experiences (ACEs):an observational study using electronic health records
Objectives To examine the relationships between adverse childhood experiences (ACEs), chronic health and health service utilisation among a sample of general practice patients.Design Cross-sectional observational study using anonymised data from electronic health records for 763 patients.Setting Four general practices in northwest England and North Wales.Outcome measures Patient demographic data (age, gender); body mass index; self-reported smoking status; self-reported ACEs; diagnosis of chronic health conditions; current mental health problems; total number of service contacts and repeat medication use in the previous 6 months.Results A history of ACEs (experiencing abuse or neglect as a child, and/or growing up in a household characterised by violence, substance use, mental health problems or criminal behaviour) was strongly independently associated with current mental health problems, smoking and chronic obstructive pulmonary disease, showing a dose–response relationship with level of ACE exposure. Medication use and contact were significantly greater among patients with high ACE exposure (≥4 ACEs), compared with those with no ACEs. However, contrary to findings from population studies, health service utilisation was not significantly different for patients with increased ACE exposure (1–3 ACEs) and their ACE-free counterparts.Conclusions Findings highlight the contribution ACEs make to unequal distributions of risk to health and well-being and patterns of health service use in the UK
Perceptions of a short animated film on adverse childhood experiences: a mixed methods evaluation
OBJECTIVES: An evaluation of a short animated film on adverse childhood experiences (ACEs) to explore attitudes and sentiment towards the film including, for a subsample of professionals, associations between attitudes and personal experience of ACEs. DESIGN: Mixed-method exploratory design. SETTING: Professionals and the general public. PARTICIPANTS: A short online survey with 239 professionals. Interaction and user sentiment towards with the film on social media (Twitter, YouTube). PRIMARY AND SECONDARY OUTCOME MEASURES: Survey: participants’ attitudes towards the film including feelings invoked, learning gained and ACE count prevalence. Twitter user and YouTube viewer sentiment (positive, negative or neutral) and interaction (likes, retweets or comments) with the film. RESULTS: Attitudes to the film were positive: 94.1% and 93.7%, respectively, agreed that it provided a helpful explanation of ACEs and trusted that the film was credible. Of those who reported ACE exposure, 88.9% agreed that those with ACEs would benefit from watching the film. Despite 50.6% reporting that the film had made them feel sad or upset, the majority (66.4%) reported they found the film hopeful or encouraging. Across 358 publicly available tweets from 313 users, 39.1% of tweets expressed positive sentiment, with only 1.4% negative (59.5% neutral). However, there was no association between tweet sentiment and interaction. Thirteen YouTube versions of the film received 171 812 views, 97.3% (n=889/914) ratings were positive (ie, ‘thumbs up’). CONCLUSIONS: Despite being emotionally arousing, many professionals reflected positive impacts of the film including a perceived increased ability to discuss ACEs. Public sentiment demonstrated a positive reaction to and acceptability of the film. Understanding the professional and public response to materials developed to increase ACE awareness, such as the film explored here, is important given the growing number of international movements which seek to increase ACE awareness, prevent ACEs and mitigate their lifelong negative effects
A molecular phylogeny of Southeast Asian Cyrtandra (Gesneriaceae) supports an emerging paradigm for Malesian plant biogeography
The islands of Southeast Asia comprise one of the most geologically and biogeographically complex areas in the world and are a centre of exceptional floristic diversity, harbouring 45,000 species of flowering plants. Cyrtandra, with over 800 species of herbs and shrubs, is the largest genus in the family Gesneriaceae and is one of the most emblematic and species-rich genera of the Malesian rainforest understorey. The high number of species and tendency to narrow endemism make Cyrtandra an ideal genus for examining biogeographic patterns. We sampled 128 Cyrtandra taxa from key localities across Southeast Asia to evaluate the geo-temporal patterns and evolutionary dynamics of this clade. One nuclear and four chloroplast regions were used for phylogenetic reconstruction, molecular dating, and ancestral range estimation. Results from the dating analysis suggest that the great diversity of Cyrtandra seen in the Malesian region results from a recent radiation, with most speciation taking place in the last five million years. Borneo was recovered as the most likely ancestral range of the genus, with the current distribution of species resulting from a west to east migration across Malesia that corresponds with island emergence and mountain building. Lastly, our investigation into the biogeographic history of the genus indicates high levels of floristic exchange between the islands on the Sunda shelf and the important role of the Philippines as a stepping stone to Wallacea and New Guinea. These patterns underlie much of the plant diversity in the region and form an emerging paradigm in Southeast Asian plant biogeography
Molecular evolution of UCP1 and the evolutionary history of mammalian non-shivering thermogenesis
<p>Abstract</p> <p>Background</p> <p>Uncoupling protein 1 (UCP1) is a mitochondrial anion carrier, expressed in brown adipose tissue (BAT) of Eutherians. UCP1 is responsible for uncoupling mitochondrial proton transport from the production of ATP, thereby dissipating heat; it is essential for non-shivering thermogenesis (NST) in mammalian BAT. UCP1 orthologs have been identified in non-Eutherian mammals, fish and amphibians. Yet, UCP1 has a unique function in Eutherians in that it is necessary in the production of heat (NST). As such, this study aims to determine the evolutionary mode of UCP1 in Eutherians, where there is clear evidence of UCP1-dependent NST in BAT.</p> <p>Results</p> <p>Models of adaptive evolution through phylogenetic analysis of amino acid sequences by maximum likelihood were implemented to determine the mode of UCP1 protein evolution in Eutherians. An increase in the rate of amino acid substitutions on the branch leading to Eutherians is observed, but is best explained by relaxed constraints, not positive selection. Further, evidence for branch and site heterogeneity in selection pressures, as well as divergent selection pressures between UCP1 and its paralogs (UCP2-3) is observed.</p> <p>Conclusion</p> <p>We propose that the unique thermogenic function of UCP1 in Eutherians may be best explained by neutral processes. Along with other evidence, this suggests that the primary biochemical properties of UCP1 may not differ between Eutherians and non-Eutherians.</p
Molecular evolution of UCP1 and the evolutionary history of mammalian non-shivering thermogenesis
<p>Abstract</p> <p>Background</p> <p>Uncoupling protein 1 (UCP1) is a mitochondrial anion carrier, expressed in brown adipose tissue (BAT) of Eutherians. UCP1 is responsible for uncoupling mitochondrial proton transport from the production of ATP, thereby dissipating heat; it is essential for non-shivering thermogenesis (NST) in mammalian BAT. UCP1 orthologs have been identified in non-Eutherian mammals, fish and amphibians. Yet, UCP1 has a unique function in Eutherians in that it is necessary in the production of heat (NST). As such, this study aims to determine the evolutionary mode of UCP1 in Eutherians, where there is clear evidence of UCP1-dependent NST in BAT.</p> <p>Results</p> <p>Models of adaptive evolution through phylogenetic analysis of amino acid sequences by maximum likelihood were implemented to determine the mode of UCP1 protein evolution in Eutherians. An increase in the rate of amino acid substitutions on the branch leading to Eutherians is observed, but is best explained by relaxed constraints, not positive selection. Further, evidence for branch and site heterogeneity in selection pressures, as well as divergent selection pressures between UCP1 and its paralogs (UCP2-3) is observed.</p> <p>Conclusion</p> <p>We propose that the unique thermogenic function of UCP1 in Eutherians may be best explained by neutral processes. Along with other evidence, this suggests that the primary biochemical properties of UCP1 may not differ between Eutherians and non-Eutherians.</p
Pro-oxidant effect of α-tocopherol in patients with Type 2 Diabetes after an oral glucose tolerance test – a randomised controlled trial
BACKGROUND: As a part of a larger study investigating the effects of α-tocopherol on gene expression in type 2 diabetics we observed a pro-oxidant effect of α-tocopherol which we believe may be useful in interpreting outcomes of large intervention trials of α-tocopherol. METHODS: 19 type 2 diabetes subjects were randomised into two groups taking either 1200 IU/day of α-tocopherol or a matched placebo for 4 weeks. On day 0 and 29 of this study oxidative DNA damage was assessed in mononuclear cells from fasted blood samples and following a 2 h glucose tolerance test (GTT). RESULTS: On day 0 there was no significant difference in oxidative DNA damage between the two groups or following a GTT. On day 29 there was no significant difference in oxidative DNA damage in fasted blood samples, however following a GTT there was a significant increase in oxidative DNA damage in the α-tocopherol treatment group. CONCLUSION: High dose supplementation with α-tocopherol primes mononuclear cells from patients with type 2 diabetes for a potentially damaging response to acute hyperglycaemia
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