2,290 research outputs found
Applications of satellite technology to broadband ISDN networks
Two satellite architectures for delivering broadband integrated services digital network (B-ISDN) service are evaluated. The first is assumed integral to an existing terrestrial network, and provides complementary services such as interconnects to remote nodes as well as high-rate multicast and broadcast service. The interconnects are at a 155 Mbs rate and are shown as being met with a nonregenerative multibeam satellite having 10-1.5 degree spots. The second satellite architecture focuses on providing private B-ISDN networks as well as acting as a gateway to the public network. This is conceived as being provided by a regenerative multibeam satellite with on-board ATM (asynchronous transfer mode) processing payload. With up to 800 Mbs offered, higher satellite EIRP is required. This is accomplished with 12-0.4 degree hopping beams, covering a total of 110 dwell positions. It is estimated the space segment capital cost for architecture one would be about 250M. The net user cost is given for a variety of scenarios, but the cost for 155 Mbs services is shown to be about $15-22/minute for 25 percent system utilization
Energy coupling of membrane transport and efficiency of sucrose dissimilation in yeast
Proton coupled transport of α-glucosides via Mal11 into Saccharomyces cerevisiae costs one ATP per imported molecule. Targeted mutation of all three acidic residues in the active site resulted in sugar uniport, but expression of these mutant transporters in yeast did not enable growth on sucrose. We then isolated six unique transporter variants of these mutants by directed evolution of yeast for growth on sucrose. In three variants, new acidic residues emerged near the active site that restored proton-coupled sucrose transport, whereas the other evolved transporters still catalysed sucrose uniport. The localization of mutations and transport properties of the mutants enabled us to propose a mechanistic model of proton-coupled sugar transport by Mal11. Cultivation of yeast strains expressing one of the sucrose uniporters in anaerobic, sucrose-limited chemostat cultures indicated an increase in the efficiency of sucrose dissimilation by 21% when additional changes in strain physiology were taken into account. We thus show that a combination of directed and evolutionary engineering results in more energy efficient sucrose transport, as a starting point to engineer yeast strains with increased yields for industrially relevant products
Social threat indirectly increases moral condemnation via thwarting fundamental social needs.
Funder: Bill and Melinda Gates Foundation; doi: http://dx.doi.org/10.13039/100000865Individuals who experience threats to their social needs may attempt to avert further harm by condemning wrongdoers more severely. Three pre-registered studies tested whether threatened social esteem is associated with increased moral condemnation. In Study 1 (N = 381) participants played a game in which they were socially included or excluded and then evaluated the actions of moral wrongdoers. We observed an indirect effect: Exclusion increased social needs-threat, which in turn increased moral condemnation. Study 2 (N = 428) was a direct replication, and also showed this indirect effect. Both studies demonstrated the effect across five moral foundations, and was most pronounced for harm violations. Study 3 (N = 102) examined dispositional concerns about social needs threat, namely social anxiety, and showed a positive correlation between this trait and moral judgments. Overall, results suggest threatened social standing is linked to moral condemnation, presumably because moral wrongdoers pose a further threat when one's ability to cope is already compromised
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Disease and Disapproval: COVID-19 Concern is Related to Greater Moral Condemnation.
Prior research has indicated that disease threat and disgust are associated with harsher moral condemnation. We investigated the role of a specific, highly salient health concern, namely the spread of the coronavirus, and associated COVID-19 disease, on moral disapproval. We hypothesized that individuals who report greater subjective worry about COVID-19 would be more sensitive to moral transgressions. Across three studies (N = 913), conducted March-May 2020 as the pandemic started to unfold in the United States, we found that individuals who were worried about contracting the infectious disease made harsher moral judgments than those who were relatively less worried. This effect was not restricted to transgressions involving purity, but extended to transgressions involving harm, fairness, authority, and loyalty, and remained when controlling for political orientation. Furthermore, for Studies 1 and 2 the effect also was robust when taking into account the contamination subscale of the Disgust Scale-Revised. These findings add to the growing literature that concrete threats to health can play a role in abstract moral considerations, supporting the notion that judgments of wrongdoing are not based on rational thought alone
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