1,814 research outputs found
The Study of the Regulon of OxyR in Escherichia coli and Porphyromonas gingivalis
The facultative anaerobe, Escherichia coli and the obligate anaerobe, Porphyromonas gingivalis are two bacteria that reside in our body. Although they reside in separate environments, they are both subject to hydrogen peroxide stress and have mechanisms to regulate the stress. OxyR is the primary transcriptional regulator/sensor of oxidative stress response caused by hydrogen peroxide. OxyR in P. gingivalis is not well-characterized compared to OxyR in E. coli. We sought to characterize and compare the two forms of OxyR in order to gain a better understanding of the protein. We determined the oligomeric state of both proteins: primarily a tetramer for E. coli and primarily a tetramer for P. gingivalis OxyR.. We demonstrated DNA binding with E. coli OxyR, indicating purification of the functional form of E. coli OxyR.Through pulldown assays we discovered potential novel binding targets, mobB for E. coli OxyR and PG1209 for P. gingivalis OxyR. Many of the other targets corresponded to intergenic regions within genes, which may pertain to small RNAs or small proteins. These results show that OxyR in E. coli and P. gingivalis has novel function and properties indicating an expanded role in addition to the well-characterized oxidative stress response
Experimental harvesting of juvenile common octopus Octopus vulgaris, for commercial ongrowing in the Azores
Octopus aquaculture is currently restricted to ongrowing of sub-adult to commercial size
because culture of paralarvae remains a bottleneck. In most countries, commercial
ongrowing rely upon existing pot fisheries for octopuses for obtaining their specimens. In the Azores, such fishery does not exist and effective methods of harvest are required if farming is to be implemented. In this study, we investigated the potential of obtaining subadult octopuses on the coast of Faial Island, Azores. Two sets of traps (n=30) consisting of 3 PVC tubes within cement blocks were set-up on two different substrates; soft sediment (Pedro Miguel) and rocky-sand (Pasteleiro) at depth varying between 10 and 30 metres. From June to August 2006, 11 hauls per site were performed. A total of 191 octopuses
(from 1.1 to 989 g; average = 135.3 g) were captured. Catches in the soft sediment site were significantly higher than in the other location (CPUE: mean ± SD: 0.33 ± 0.17 vs. 0.15 ± 0.17 octopus trap-1 hour-1*100). The catch was initially dominated by octopus of 300-400 g but as fishing continued, this size classes disappeared and was replaced by smaller individuals. As a result, half of the catch at both sites (51.8%) was composed of specimens with a weight equal or inferior to 50 grams. The occurrence of summer recruitment event combined with a natural displacement of larger individuals into deeper waters is most probably responsible for this pattern. Our results showed that in shallow water and during this period of the year, individuals inferior to 50 grams are far more abundant than larger octopuses and should be the target size class for ongrowing activities
Recruitment and growth of Megabalanus azoricus (Pilsbry, 1916) on artificial substrates: first steps towards commercial culture in the Azores
This paper reports the results of preliminary research evaluating the potential of farming Megabalanus azoricus. From March 2006 to September 2006, artificial substrates were immersed bi-monthly in a shallow water bank located in the channel separating the islands of Faial and Pico, Azores. They were monitored monthly for a period of 12 months by scuba-diving. M. azoricus rapidly colonised the immersed substrates, establishing itself as the dominant organism. Even though recruitment was observed year round, there was a peak in recruitment between June and October. The substrate immersed for the longest period (15 months) presented final densities of 1109 ind. m-2, from which 20.2% were of edible size. Growth was monitored for 18 isolated barnacles for 8 months. Growth rate proved to be high (base diameter; 0.08 ± 0.02 mm day-1; mean ± SD), with individuals reaching diameters of 21.35 ± 6.2 mm after 8 months. Considering this growth rate, it was estimated that after a further 9 months, over 80% of the total densities (on the oldest substrate ) would be harvestable, thus suggesting a production cycle of 17 to 24 months. Although much further research is needed, the species presents all characteristics of a potential candidate to initiate the aquaculture industry in the Azores
A Multi-Objective Optimization for Supply Chain Network Using the Bees Algorithm
A supply chain is a complex network which involves the products, services and information flows between suppliers and customers. A typical supply chain is composed of different levels, hence, there is a need to optimize the supply chain by finding the optimum configuration of the network in order to get a good compromise between the multi-objectives such as cost minimization and lead-time minimization. There are several multi-objective optimization methods which have been applied to find the optimum solutions set based on the Pareto front line. In this study, a swarm-based optimization method, namely, the bees algorithm is proposed in dealing with the multi-objective supply chain model to find the optimum configuration of a given supply chain problem which minimizes the total cost and the total lead-time. The supply chain problem utilized in this study is taken from literature and several experiments have been conducted in order to show the performance of the proposed model; in addition, the results have been compared to those achieved by the ant colony optimization method. The results show that the proposed bees algorithm is able to achieve better Pareto solutions for the supply chain problem
The First Cut Is the Deepest: Trawl Effects on a Deep-Sea Sponge Ground Are Pronounced Four Years on
Few studies have described the effects of physical disturbance and post-recovery of deep-sea benthic communities. Here, we explore the status of deep-sea sponge ground communities four years after being impacted by an experimental bottom trawl. The diversity and abundance of epibenthic megafauna of two distinct benthic communities in disturbed versus control areas were surveyed using a remotely operated vehicle on the Schulz Bank, Arctic Ocean. Four years after disturbance, megafaunal densities of the shallow (∼600 m depth) and deep (∼1,400 m depth) sites were significantly lower on the disturbed patches compared to the control areas. Multivariate analyses revealed a distinct separation between disturbed and control communities for both sites, with trawling causing 29–58% of the variation. Many epibenthic morphotypes were significantly impacted by the trawl, including ascidians, Geodia parva, Hexactinellida spp., Craniella infrequens, Lissodendoryx complicata, Haliclonia sp. Stylocordyla borealis, Gersemia rubiformis and Actiniaria sp. However, we found some smaller morphospecies to be equally abundant with control transects, including Polymastia thielei, Geodia hentscheli, and Stelletta rhaphidiophora, reflecting lower trawl impact for these morphotypes. Overall, our results suggest that these are fragile ecosystems that require much more time than four years to recover from physical disturbance typical of trawling activities.publishedVersio
The costs of traumatic brain injury due to motorcycle accidents in Hanoi, Vietnam
Background: Road traffic accidents are the leading cause of fatal and non-fatal injuries in Vietnam. The purpose of this study is to estimate the costs, in the first year post-injury, of non-fatal traumatic brain injury (TBI) in motorcycle users not wearing helmets in Hanoi, Vietnam. The costs are calculated from the perspective of the injured patients and their families, and include quantification of direct, indirect and intangible costs, using years lost due to disability as a proxy. Methods: The study was a retrospective cross-sectional study. Data on treatment and rehabilitation costs, employment and support were obtained from patients and their families using a structured questionnaire and The European Quality of Life instrument (EQ6D). Results: Thirty-five patients and their families were interviewed. On average, patients with severe, moderate and minor TBI incurred direct costs at USD 2,365, USD 1,390 and USD 849, with time lost for normal activities averaging 54 weeks, 26 weeks and 17 weeks and years lived with disability (YLD) of 0.46, 0.25 and 0.15 year, respectively. Conclusion: All three component costs of TBI were high; the direct cost accounted for the largest proportion, with costs rising with the severity of TBI. The results suggest that the burden of TBI can be catastrophic for families because of high direct costs, significant time off work for patients and caregivers, and impact on health-related quality of life. Further research is warranted to explore the actual social and economic benefits of mandatory helmet use
Microplastics in beach sediments of the Azores archipelago, NE Atlantic
Funding Information: The authors would like to acknowledge the funds provided by the Gallifrey Foundation and the International Union for the Conservation of Nature (IUCN) through the project Azorlit (Project Number - P01495). Okeanos received national funds through the Foundation for Science and Technology (FCT) and Instituto Público (I.P.), under the project UIDB/05634/2020 and UIDP/05634/2020 and through the Regional Government of the Azores (M1.1.A/REEQ.CIENTÍFICO UIandD/2021/010). C.K.P. was co-financed by the Operational Program AZORES 2020, through the Fund 01-0145-FEDER-000140 ‘MarAZ Researchers: Consolidate a body of researchers in Marine Sciences in the Azores’ of the European Union. Y.R. was funded by a PhD scholarship from the Regional Fund of Science and Technology, Government of the Azores (M3.1.a/F/022/2020). Joana Antunes and Paula Sobral were supported by FCT through the strategic projects UIDB/04292/2020 granted to MARE and the project LA/P/0069/2020 granted to the Associate Laboratory ARNET. Publisher Copyright: © 2024 The AuthorsOceanic islands are exposed to plastic debris that has accumulated in the open ocean, particularly in the subtropical gyres. This study investigates the abundance and typology of microplastics (from 0.1 to 5 mm) on 19 sandy beaches spread across 8 oceanic islands of the Azores archipelago. Between January and April 2016, a total of 341 particles retrieved from all beaches, were identified as microplastics. The highest concentration (50.19 ± 21.93 particles kg−1 dw) was found in Terceira Island. Beach morphology and grain size were important factors explaining microplastic concentration. Fibres were the most dominant morphology recovered (80.9 %), followed by fragments (12.3 %). Fourier transform infrared spectroscopy (FTIR) revealed that 41 % of the fibres consisted of polyester and 60 % of the fragments were polyethylene. This research underlines the widespread contamination of microplastics in oceanic islands of the Atlantic Ocean.publishersversionpublishe
The effects of a whey protein and guar gum-containing preload on gastric emptying, glycaemia, small intestinal absorption and blood pressure in healthy older subjects
A whey protein/guar gum preload reduces postprandial glycaemia in type 2 diabetes through slowing gastric emptying. However, gastric emptying has previously been assessed using a stable isotope breath test technique, which cannot discriminate between slowing of gastric emptying and small intestinal absorption. This preload also may be useful in the management of postprandial hypotension. We evaluated the effects of a whey protein/guar preload on gastric emptying, glucose absorption, glycaemic/insulinaemic and blood pressure (BP) responses to an oral glucose load. Eighteen healthy older participants underwent measurements of gastric emptying (scintigraphy), plasma glucose and insulin, glucose absorption, superior mesenteric artery (SMA) flow, BP and heart rate (HR) after ingesting a 50 g glucose drink, with or without the preload. The preload reduced plasma glucose (p = 0.02) and serum 3-O-methylglucose (3-OMG) (p = 0.003), and increased plasma insulin (p = 0.03). There was no difference in gastric emptying or BP between the two days. The reduction in plasma glucose on the preload day was related to the reduction in glucose absorption (r = 0.71, p = 0.002). In conclusion, the glucose-lowering effect of the preload may relate to delayed small intestinal glucose absorption and insulin stimulation, rather than slowing of gastric emptying.publishedVersio
- …