120 research outputs found
System for measuring passenger reaction to transportation-vehicle vibration
Equipment is capable of measuring frequencies from 0 to 50 Hz and is portable, light, inexpensive, and easily adaptable to field operations. System could be used in situations where it is necessary to record simultaneously subject response to other types of physical measurement or stimuli, such as temperature, noise, or pressure
Non-equilibrium cobalt(III) "click" capsules
Cobalt(III) tetrahedral capsules have been prepared using an assembly-followed-by-oxidation protocol from a cobalt(II) precursor and a readily derivatizable pyridyl-triazole ligand system. Experiments designed to probe the constitutional dynamics show that these architectures are in a non-equilibrium state. A preliminary investigation into the hostâguest chemistry of a water-soluble derivative shows it can bind and differentiate a range of different neutral organic molecules. The stability of this ensemble also permits the study of guest-binding at high salt concentrations
Susceptibility of optimal train schedules to stochastic disturbances of process times
This work focuses on the stochastic evaluation of train schedules computed by a microscopic scheduler of railway operations based on deterministic information. The research question is to assess the degree of sensitivity of various rescheduling algorithms to variations in process times (running and dwell times). In fact, the objective of railway traffic management is to reduce delay propagation and to increase disturbance robustness of train schedules at a network scale. We present a quantitative study of traffic disturbances and their effects on the schedules computed by simple and advanced rescheduling algorithms. Computational results are based on a complex and densely occupied Dutch railway area; train delays are computed based on accepted statistical distributions, and dwell and running times of trains are subject to additional stochastic variations. From the results obtained on a real case study, an advanced branch and bound algorithm, on average, outperforms a First In First Out scheduling rule both in deterministic and stochastic traffic scenarios. However, the characteristic of the stochastic processes and the way a stochastic instance is handled turn out to have a serious impact on the scheduler performance
Medical-grade honey enriched with antimicrobial peptides has enhanced activity against antibiotic-resistant pathogens
Honey has potent activity against both antibiotic-sensitive and -resistant bacteria, and is an interesting agent for topical antimicrobial application to wounds. As honey is diluted by wound exudate, rapid bactericidal activity up to high dilution is a prerequisite for its successful application. We investigated the kinetics of the killing of antibiotic-resistant bacteria by RS honey, the source for the production of RevamilÂź medical-grade honey, and we aimed to enhance the rapid bactericidal activity of RS honey by enrichment with its endogenous compounds or the addition of antimicrobial peptides (AMPs). RS honey killed antibiotic-resistant isolates of Pseudomonas aeruginosa, Staphylococcus epidermidis, Enterococcus faecium, and Burkholderia cepacia within 2 h, but lacked such rapid activity against methicillin-resistant S. aureus (MRSA) and extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. It was not feasible to enhance the rapid activity of RS honey by enrichment with endogenous compounds, but RS honey enriched with 75Â ÎŒM of the synthetic peptide Bactericidal Peptide 2 (BP2) showed rapid bactericidal activity against all species tested, including MRSA and ESBL E. coli, at up to 10â20-fold dilution. RS honey enriched with BP2 rapidly killed all bacteria tested and had a broader spectrum of bactericidal activity than either BP2 or honey alone
What is the origin of the Scottish populations of the European endemic Cherleria sedoides
Invading and expanding : range dynamics and ecological consequences of the Greater White-Toothed Shrew (Crocidura russula) invasion in Ireland
Establishing how invasive species impact upon pre-existing species is a fundamental question in ecology and conservation
biology. The greater white-toothed shrew (Crocidura russula) is an invasive species in Ireland that was first recorded in 2007
and which, according to initial data, may be limiting the abundance/distribution of the pygmy shrew (Sorex minutus),
previously Irelandâs only shrew species. Because of these concerns, we undertook an intensive live-trapping survey (and
used other data from live-trapping, sightings and bird of prey pellets/nest inspections collected between 2006 and 2013) to
model the distribution and expansion of C. russula in Ireland and its impacts on Irelandâs small mammal community. The
main distribution range of C. russula was found to be approximately 7,600 km2 in 2013, with established outlier populations
suggesting that the species is dispersing with human assistance within the island. The species is expanding rapidly for a
small mammal, with a radial expansion rate of 5.5 km/yr overall (2008â2013), and independent estimates from live-trapping
in 2012â2013 showing rates of 2.4â14.1 km/yr, 0.5â7.1 km/yr and 0â5.6 km/yr depending on the landscape features
present. S. minutus is negatively associated with C. russula. S. minutus is completely absent at sites where C. russula is
established and is only present at sites at the edge of and beyond the invasion range of C. russula. The speed of this invasion
and the homogenous nature of the Irish landscape may mean that S. minutus has not had sufficient time to adapt to the
sudden appearance of C. russula. This may mean the continued decline/disappearance of S. minutus as C. russula spreads
throughout the island
Recommended from our members
Hydrologic and Biotic Effects of Grazing vs. Non-grazing Near Grand Junction, Colorado
The effect of grazing on the hydrology of salt-desert type rangeland has been studied near Grand Junction, Colorado for the past 14 years. Measurements of precipitation, runoff, erosion, and vegetation have been made in four pairs of watersheds. One of each pair has been grazed by cattle and sheep as is normal in the region, and the other has not been used since the beginning of the study. Measurements made 10 years apart show that all four grazed watersheds have had a slight increase in the amount of bare soil and rock and a decrease in ground cover; cover on ungrazed watersheds has remained essentially unchanged. Runoff in the ungrazed watersheds has been about 30 percent less than in the grazed watersheds and sediment yield has been about 45 percent less. The greatest change in each of the relationships occurred about 3 years after livestock were excluded from one watershed of each of the pairs. Preliminary studies indicate that within areas of similar physiography, runoff is directly related to the percentage of bare soil present on a watershed.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
- âŠ