Prevention of Erosion in Hooper Bay, Alaska

A Project Submitted in Partial Requirement of the Requirements for the Degree of MASTER OF SCIENCE in Civil EngineeringMany rural communities in Alaska are at risk of losing infrastructure to erosion. One of these communities is Hooper Bay, on the west coast of Alaska. According to predictions generated by the Alaska Department of Natural Resources, several hundred feet of airport runway and road will be exposed to erosion between the years of 2015 and 2075. While the runway’s current erosion mitigation measures are effective, overtopping and the depositing of debris remain an issue. There are currently community measures underway to elevate the endangered section of road, and there are plans to implement more rigorous protect in place measures within the next 10 years. A salient is present on the coast south of the runway that is slowly moving north. The exact mechanics behind its formation and movement are not known, but it may provide natural beach nourishment to the beach near the runway within the next 15 years. Continued observation, data collection and research is required to identify effective, long term solutions to the erosion problem, but the measures currently in place, being implemented, and planned should provide short term protection

Efficacy of five ‘sporicidal’ surface disinfectants against Clostridioides difficile spores in suspension tests and 4-field tests

Background: A sporicidal surface disinfection is recommended both for the outbreak and the endemic setting but a comparative evaluation on the efficacy of ‘sporicidal’ surface disinfectants using suspension tests and 4-field tests has not been performed. Aim: To determine the efficacy of five ‘sporicidal’ surface disinfectants (three ready-to-use wipes (A, B, E), two concentrates (C, D) based on peroxides or aldehydes against C. difficile spores. Methods: The efficacy was determined under clean conditions using a suspension test and the 4-field test. Each test was performed in duplicate in two separate laboratories. Wipes were wrung to collect the solution for the suspension tests. Results: Product A (peracetic acid; 5 min), product C (peracetic acid; 2% solution in 15 min or 1% solution in 30 min) and product D (peracetic acid; only 2% solution in 15 min) were effective with at least a 4 log10-reduction of C. difficile spores in suspension and on surfaces. Product B (hydrogen peroxide) was not effective in suspension (0.9 log10 after 15 min; 3.2 log10 after 1 h) and on surfaces (2.8 log10 after 15 and 60 min). Product E based on glutaraldehyde, (ethylendioxy)dimethanol and DDAC demonstrated 0.9 log10 after 4 h in suspension and 4.5 log10 after 4 h on surfaces. Conclusions: Not all surface disinfectants with a sporicidal claim were effective against C. difficile spores in standardized suspension tests and in the 4-field test. In clinical practice preference should be given to products that reliably pass the efficacy criteria of both types of tests.Peer Reviewe

Spatiotemporal Patterns of Transitional Landscapes in the Southwest Missouri Ozarks

Springfield, Missouri\u27s surrounding communities have experienced population increases that greatly impact the landscape\u27s ecological systems and processes. These changes are primarily products of the shift of land use practices and an alteration of land cover to accommodate an expanding population and associated construction of housing developments, shopping centers, and other urban infrastructure. The neighboring cities of Nixa and Ozark, in Christian County, lie within this area of urban sprawl. These transitional landscapes were monitored from 1979 to 2004 with remote sensing and geographic information systems to evaluate the changes in landscape pattern. This was accomplished though supervised classification using feature extraction of panchromatic, true color, and color infrared aerial photographs into land use/land cover maps, following with an accuracy analysis of the classifications. The transitional landscape patterns changes were then quantified with landscape metrics. A spatiotemporal metrics table plotting time against land use within the study area explains the scenario of patterns occurring to landscape. The study showed that urban sprawl began between 1979 and 1990, with the largest decline in total forest area for all intervals and the largest amount of fragmentation within the forest class occurring within this time period. The background matrix yielded the most area to impervious growth between 1990 and 2003, when the largest population increase occured and the average area of impervious patches grew substantially, while the number of patches remained relatively stable. 2004 saw a decline in the number of patches and an increase in average patch area, suggesting that urban sprawl would evolve to only a few large, interconnected patches

A description of defensive hiss types in the flat horned hissing cockroach (Aeluropoda insignis)

Acoustic communication can inform studies of behaviour and phylogeny in insect species. Despite there being 4600 described species of cockroach, few studies have focused on their ability to communicate acoustically. Cockroaches have been found to produce sound in a variety of ways. Species within the tribe Gromphadorhini produce sound through modified spiracles, often referred to as hisses. Sound parameters have been described for the species Gromphadorhina portentosa and Elliptorhina chopardi. Aeluropoda insignis, within the same tribe, produces sound and is morphologically similar to these two species, but no research has been published describing its acoustic signals. Our study explores the defensive acoustic signals of this species and indicates that A. insignis is capable of producing three classes of acoustic signals (whistles, whistle–hisses and hisses) associated with defensive behaviour. Sexes differed in the entropy and the frequency of their signals, with males producing signals with lower entropy and at higher frequency than females. Future studies on acoustic communication within Blattodea could give more insight into the complexity of signals and their relationship to behavioural context