8,707 research outputs found
Searching for Fast Optical Transients using VERITAS Cherenkov Telescopes
Astronomical transients are intrinsically interesting things to study. Fast
optical transients (microsecond timescale) are a largely unexplored field of
optical astronomy mainly due to the fact that large optical telescopes are
oversubscribed. Furthermore, most optical observations use instruments with
integration times on the order of seconds and are thus unable to resolve fast
transients. Current-generation atmospheric Cherenkov gamma-ray telescopes,
however, have huge collecting areas (e.g., VERITAS, which consists of four 12-m
telescopes), larger than any existing optical telescopes, and time is typically
available for such studies without interfering with gamma-ray observations. The
following outlines the benefits of using a Cherenkov telescope to detect
optical transients and the implementation of the VERITAS Transient Detector
(TRenDy), a dedicated multi-channel photometer based on field-programmable gate
arrays. Data are presented demonstrating the ability of TRenDy to detect
transient events such as a star passing through its field of view and the
optical light curve of a pulsar
Creating an integrated payment system: the evolution of Fedwire
Adapted from remarks given before the Seminar on Payment Systems in the European Union in Frankfurt, Germany, on February 27, 1997.Fedwire ; Electronic funds transfers ; Federal Reserve System
The Role of Information and Communication Technology (ICT) in Enhancing the Innovative Learning Process
The most significant instruments in the learning cycle are the educator and learning media. Obviously, the utilization and choice of fitting instructional media completed by an instructor will have an impact on the cycle and consequences of the learning. For this situation, data and correspondence innovation based learning media is the most significant thing in the advancement of the universe of training. Data and Communication Technology (ICT) is a program for instruments, control and passing on of data and information to make it simpler in the learning cycle in the homeroom. With ICT-based learning media, understudies can create thinking abilities and improve instructor aptitudes expertly. Educators become more propelled and inventive in homeroom learning. The reason for this investigation was to decide the function of educators in utilizing learning media dependent on Information and Communication Technology
Structure- and context-based analysis of the GxGYxYP family reveals a new putative class of glycoside hydrolase.
BackgroundGut microbiome metagenomics has revealed many protein families and domains found largely or exclusively in that environment. Proteins containing the GxGYxYP domain are over-represented in the gut microbiota, and are found in Polysaccharide Utilization Loci in the gut symbiont Bacteroides thetaiotaomicron, suggesting their involvement in polysaccharide metabolism, but little else is known of the function of this domain.ResultsGenomic context and domain architecture analyses support a role for the GxGYxYP domain in carbohydrate metabolism. Sparse occurrences in eukaryotes are the result of lateral gene transfer. The structure of the GxGYxYP domain-containing protein encoded by the BT2193 locus reveals two structural domains, the first composed of three divergent repeats with no recognisable homology to previously solved structures, the second a more familiar seven-stranded β/α barrel. Structure-based analyses including conservation mapping localise a presumed functional site to a cleft between the two domains of BT2193. Matching to a catalytic site template from a GH9 cellulase and other analyses point to a putative catalytic triad composed of Glu272, Asp331 and Asp333.ConclusionsWe suggest that GxGYxYP-containing proteins constitute a novel glycoside hydrolase family of as yet unknown specificity
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Impacts of indoor surface finishes on bacterial viability.
Microbes in indoor environments are constantly being exposed to antimicrobial surface finishes. Many are rendered non-viable after spending extended periods of time under low-moisture, low-nutrient surface conditions, regardless of whether those surfaces have been amended with antimicrobial chemicals. However, some microorganisms remain viable even after prolonged exposure to these hostile conditions. Work with specific model pathogens makes it difficult to draw general conclusions about how chemical and physical properties of surfaces affect microbes. Here, we explore the survival of a synthetic community of non-model microorganisms isolated from built environments following exposure to three chemically and physically distinct surface finishes. Our findings demonstrated the differences in bacterial survival associated with three chemically and physically distinct materials. Alkaline clay surfaces select for an alkaliphilic bacterium, Kocuria rosea, whereas acidic mold-resistant paint favors Bacillus timonensis, a Gram-negative spore-forming bacterium that also survives on antimicrobial surfaces after 24Â hours of exposure. Additionally, antibiotic-resistant Pantoea allii did not exhibit prolonged retention on antimicrobial surfaces. Our controlled microcosm experiment integrates measurement of indoor chemistry and microbiology to elucidate the complex biochemical interactions that influence the indoor microbiome
The oil production response to Alberta's government-mandated quota
Two years ago, the Alberta government put in place a temporary oil-production quota. However, the quota’s impact could well be felt in the province’s oil production for years to come. The quota applied only to firms producing more than 10,000 barrels of oil per day and was instituted as a response to pipeline constraints that caused Alberta oil prices to be much lower than prices elsewhere. Production from both oilsands mines and oil wells dropped as soon as the government announced the quotas. The media warned that the quotas would force production to transfer to Saskatchewan, but the research for this paper found that this never occurred.
The quota policy was announced in December 2018 and a week later, the price of Alberta oil had jumped from 50.08 bbl, a 72 per cent rise. When the quota policy actually took effect the first of January 2019, the price increased again, but by much less. The anticipation of the quota alone was enough to create the desired price increase.
The quota, which set limits for the total combined crude oil and bitumen permitted to be produced, was assigned to individual operators and designed to provide an 8.5 per cent reduction in oil production. The total quota was fixed at 3.56 million barrels a day in January 2019, but individual quotas could be traded across eligible operators, minimizing the overall costs of achieving the total goal. However, total production continued falling even when the quota was eventually relaxed; the market and a low world price created a scenario in which production fell below the amount permitted by the quota. All the oil companies reduced their production regardless of whether they fell within the quota’s guidelines or not; however, the firms that were subject to the quota reduced their production more than the others. The quota was lifted in December 2020 when export capacity again became sufficient.
While curtailing production had the desired result of raising Alberta oil prices and resolving the differential between local prices and the world benchmark, its ripple effects may well be felt in the longer term. This paper finds that fewer wells are being drilled and more wells are suspending production. Tradition dictates that when a well becomes inactive, it is rarely returned to a productive state. Those firms that resorted to low levels of drilling in order to meet the quota have created a situation that could affect Alberta oil production in the years ahead
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