| 30291. |
- Dang, Hung The, et al.
(författare)
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Syntheses and biological evaluation of 2-amino-3-acyl-tetrahydrobenzothiophene derivatives : antibacterial agents with antivirulence activity
- 2014
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Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 12:12, s. 1942-1956
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Tidskriftsartikel (refereegranskat)abstract
- Developing new compounds targeting virulence factors (e.g., inhibition of pilus assembly by pilicides) is a promising approach to combating bacterial infection. A high-throughput screening campaign of a library of 17 500 small molecules identified 2-amino-3-acyl-tetrahydrobenzothiophene derivatives (hits 2 and 3) as novel inhibitors of pili-dependent biofilm formation in a uropathogenic Escherichia coli strain UTI89. Based on compounds 2 and 3 as the starting point, we designed and synthesized a series of structurally related analogs and investigated their activity against biofilm formation of E. coli UTI89. Systematic structural modification of the initial hits provided valuable information on their SARs for further optimization. In addition, small structural changes to the parent molecules resulted in low micromolar inhibitors (20-23) of E. coli biofilm development without an effect on bacterial growth. The hit compound 3 and its analog 20 were confirmed to prevent pili formation in a hemagglutination (HA) titer assay and electron microscopy (EM) measurements. These findings suggest that 2-amino-3-acyl-tetrahydrobenzothiophenes may serve as a new class of compounds for further elaboration as antibacterial agents with antivirulence activity.
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| 30292. |
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| 30293. |
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| 30294. |
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| 30295. |
- Dangles, O, et al.
(författare)
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The importance of detritivore species diversity for maintaining stream ecosystem functioning following the invasion of a riparian plant
- 2002
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Ingår i: Biological Invasions. ; 4, s. 441-446
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Tidskriftsartikel (refereegranskat)abstract
- The strength of linkages between riparian plants and stream communities can be expected to be influenced by invading plants. While most studies so far have been focussed on the effects of the leaf litter quality of the invader, this study addresses the impact of detritivores on the pool of detritus. In a natural setting, we found that species richness of shredding macroinvertebrates significantly influenced the breakdown rate of an invasive weed species, the Japanese knotweed (Fallopia japonica), which has become a major plant invader along streams and rivers in Europe and North America. Our findings imply that a reduction of the diversity of shredder species, which may be the result of disturbances, could negatively influence stream ecosystems'' capacity of processing knotweed leaves. Although the knotweed showed breakdown rates similar to those of common native tree and shrub species, other exotic leaf species might show considerably slower rates and hence have greater consequences for the ecosystems. We have, in this study, indicated a technique by which the effects of other non-indigenous plants on ecosystem functioning might be considered.
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| 30296. |
- Danial, John S. H., et al.
(författare)
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Computed Histological Quantification of Atherosclerotic Plaque Microcalcifications
- 2020
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Ingår i: Angiology. - : Sage Publications. - 0003-3197 .- 1940-1574. ; 71:10, s. 916-919
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Tidskriftsartikel (refereegranskat)abstract
- Inflammation has a central role in atherosclerotic plaque formation and rupture. Intense macrophage inflammatory activity results in microcalcifications which are strongly associated with plaque vulnerability. Microcalcifications with specific critical size between 5 and 65 mu, located in the fibrous cap producing local mechanical stress on the plaque surface and may directly contribute to plaque rupture. Hence, accurate assessment of microcalcifications size and dimension has significant clinical importance. Current invasive and noninvasive plaque imaging has limited spatial resolution which limits accurate definition of microcalcifications in the atherosclerotic plaques. We describe a new imaging technique with high spatial resolution, based on confocal microscopic analysis, using a dedicated software which allows automatic characterization of microcalcifications and quantitative assessment of their extent and localization.
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| 30297. |
- Daniel, Aemiro Melkamu, 1988-, et al.
(författare)
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Accounting for Elimination-by-Aspects Strategies and Demand Management in Electricity Contract Choice
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We report on a discrete choice experiment aimed at eliciting Swedish households’ willingness-to-accept a compensation for restrictions on household electricity and heating use during peak hours. When analyzing data from discrete choice experiments, we typically assume that people make rational utility maximizing decisions, i.e., that they consider all of the attribute information and compare all alternatives. However, mounting evidence shows that people use a wide range of simplifying strategies that are inconsistent with utility maximization. We use a flexible model capturing a two-stage decision process. In the first stage, respondents are allowed to eliminate from their choice set alternatives that contain an unacceptable level, i.e., restrictions on the use of heating and electricity. In the second stage, respondents choose in a compensatory manner between the remaining alternatives. Our results show that about half of our respondents choose according to an elimination-by-aspects strategy, and that, on average, they are unwilling to accept any restrictions on heating in the evening or electricity use, irrespective of time-of-day. Furthermore, we find that considering elimination-by-aspects behavior leads to a downward shift in elicited willingness-to-accept. We discuss implications for policy.
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| 30298. |
- Daniel, Aemiro Melkamu, 1988-
(författare)
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Household fuel choice and use: A multiple discrete-continuous framework
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper provides a joint analysis of multiple fuel types and use choices and explores the socio-demographic and housing characteristics that influence household fuel use decisions. Using household survey data from urban Ethiopia, this paper estimates a mixed multiple discrete-continuous extreme value (MMDCEV) model. The results indicate that households with a female head are more likely to combine traditional biomass fuels (firewood and charcoal) and electricity for different uses, while households with less-educated heads, larger families, and poorer living conditions (fewer rooms) tend to rely on traditional biomass fuels. The results also show that households with an individual electricity meter are significantly less likely to use charcoal. Furthermore, The results show that the satiation effect from increased use of a fuel is relatively higher for firewood and lower for electricity. The findings in this paper can be useful for information energy policy, including more effective targeting of subsidies for liquefied petroleum gas (LPG) purchases and private electricity meter installations, and for interventions that promote adoption of improved biomass cookstoves.
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| 30299. |
- Daniel, Aemiro Melkamu, 1988-
(författare)
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Household heterogeneity in valuing electricity demand flexibility services
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, we look at investigating heterogeneity in households' valuation of electricity contract attributes that reflect demand-side flexibility in the Swedish residential sector. Using stated preference data generated from a choice experiment, we estimated a mixed logit model in willingness-to-pay space and derivative individual-specific conditional mean valuations for contract attributes which include various load controls and distribution of electricity consumption information. We perform a posterior analysis and identify different segments based on the monetary values households attach to the contract attributes. We find that a large proportion of households ask for substantial compensation to accept various load controls and to share their electricity consumption information. However, Some households are willing to share their electricity consumption information and ask for relatively lower compensation to allow load controls. We also find that some households that accept load controls at relatively low compensation require sizeable compensation to share their electricity consumption information, and vice versa. From the perspective of contract providers, these findings suggest that information-optional contracts can generate more customers than contracts that bundle households' consumption information with various load controls.
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| 30300. |
- Daniel, Aemiro Melkamu, 1988-
(författare)
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Towards sustainable energy consumption : Electricity demand flexibility and household fuel choice
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Paper [I] investigates household heterogeneity in valuing electricity contract attributes that include various load controls and information sharing to induce demand flexibility. Using a stated preference choice experiment conducted with Swedish households, this paper shows that, although a large proportion of households ask for substantial compensation, some households are willing to share their electricity consumption information and require relatively lower compensation to allow load controls. In addition, this paper finds that some households that are willing to provide flexibility by accepting load controls at a relatively low compensation ask for sizable compensation to share their electricity consumption information, and vice versa. From the perspective of the contract providers,Paper [II] uses a flexible model to accommodate heterogeneous decision rules in analysing data obtained from a discrete choice experiment aimed at eliciting Swedish households’ willingness to accept compensation for restrictions on household electricity and heating use during peak hours. The model combines behavioural processes based on random utility maximization with an elimination-by-aspects strategy, where the latter involves a two-stage decision process. In the first stage, respondents are allowed to eliminate from their choice set alternatives that contain an unacceptable level, in this case restrictions on the use of heating and electricity. In the second stage, respondents choose between the remaining alternatives in a rational utility maximizing manner. Our results show that about half of the respondents choose according to an elimination-by-aspects strategy, and considering elimination-by-aspects behaviour leads to a downward shift in elicited willingness-to-accept.Paper [III] tests the effect of a pro-environmental framing on households’ stated willingness to accept restrictions on their electricity use. We use a split-sample choice experiment and ask respondents to choose between their current electricity contract and hypothetical contracts featuring various load controls and monetary compensation. Our results indicate that the pro-environmental framing has little impact on the respondents’ choices. We observe a significant framing effect on choices and marginal willingness-to-accept for only a few contract attributes. The results further suggest that there is no significant framing effect among households that are already engaged in pro-environmental activities.Paper [IV] explores the socio-demographic and housing characteristics that influence household fuel choice and fuel use decisions in urban Ethiopia. The results indicate that, whereas households with a female head are more likely to combine traditional solid (firewood and charcoal) and modern (electricity) fuels for different uses, households with less-educated heads, many family members, and poor living conditions (fewer rooms) tend to use traditional solid biomass fuels. We find that households with an individual electricity meter are significantly less likely to use charcoal. Further, the results show the satiation effect of the increasing use of a fuel by households is relatively higher for firewood and lower for electricity.
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