158 research outputs found
An Economic Assessment of Space Solar Power as a Source of Electricity for Space-Based Activities
We develop a conceptual model of the economic value of space solar power (SSP) as a source of power to in-space activities, such as spacecraft and space stations. We offer several estimates of the value based on interviews and published data, discuss technological innovations that may compete with or be complementary to SSP, and consider alternative institutional arrangements for government and the private sector to provide SSP.innovation, government policy
Friends, Food, or “Free Egg Machines”? A Qualitative Study of Chicken Owners' Perceptions of Chickens and Chicken Meat.
This item is only available electronically.How people who keep household chickens, and also eat chicken meat, balance perceptions of chickens as companion animals and as meat products is unknown. This is because human-animal bonds research has neglected inquiry into relationships with domestic chickens, despite increasing rates of urban chicken ownership in Australia. People may form strong attachments to their companion animals. Conversely, people tend to enjoy eating animal meat while preferring not to think about the slaughter of meat animals. This phenomenon is called the Meat Paradox, and often produces cognitive dissonance, which people may resolve by morally disengaging from meat animals and believing that meat animals are less capable of suffering. How people view chickens is unclear as they have the potential to be both companion animals and meat products. The present study aimed to fill this gap in the research by interviewing participants (N = 10) who kept household chickens and ate chicken meat about their attitudes and behaviours regarding chickens. Thematic analysis was used to generate five themes from the data, which were Chickens are pets, Chickens are meat products, Chickens are utilities, Chickens have varying levels of individuality, and Inconsistencies and changes in perceptions. Themes were overlapping, dynamic, and contradictory. The results suggest that people can consciously attempt to control processes of empathising for, or disengaging from, animals, depending on animals’ perceived status as companions or meat products. These findings have implications for further research into cognitive dissonance, empathy, and objectification in bonds with animals, and meat attitudes.Thesis (B.PsychSc(Hons)) -- University of Adelaide, School of Psychology, 201
Can Power from Space Compete?
Satellite solar power (SSP) has been suggested as an alternative to terrestrial energy resources for electricity generation. In this study, we consider the market for electricity from the present to 2020, roughly the year when many experts expect SSP to be technically achievable. We identify several key challenges for SSP in competing with conventional electricity generation in developed and developing countries, discuss the role of market and economic analysis as technical development of SSP continues during the coming years, and suggest future research directions to improve understanding of the potential economic viability of SSP.
Noncrossing partitions, toggles, and homomesies
We introduce n(n-1)/2 natural involutions ("toggles") on the set S of non-crossing partitions π of size n, along with certain composite operations obtained by composing these involutions. We show that for many operations T of this kind, a surprisingly large family of functions f on S (including the function that sends π to the number of blocks of π) exhibits the homomesy phenomenon: the average of f over the elements of a T-orbit is the same for all T-orbits. We can apply our method of proof more broadly to toggle operations back on the collection of independent sets of certain graphs. We utilize this generalization to prove a theorem about toggling on a family of graphs called "2-cliquish." More generally, the philosophy of this "toggle-action," proposed by Striker, is a popular topic of current and future research in dynamic algebraic combinatorics
Mapping and Monitoring of Submerged Aquatic Vegetation in Escambia-Pensacola Bay System, Florida
Recently, the distribution and changes in submerged aquatic vegetation (SAY) in the Escambia-Pensacola Bay System in northeastern Florida were monitored by two techniques. One technique used divers to measure changes in the deepwater margin of beds and provided horizontal growth measurements to the nearest centimeter, the other used a differential global positioning system (DGPS) on a small boat to map the perimeter of SAY beds in shallow water. Current distribution of SAY in Escambia Bay shows that most of the SAY losses that occurred during the 1950s to 1970s have been recovered. In Santa Rosa Sound and Pensacola Bay, SAY showed significant increased growth with horizontal growth rates of some beds averaging more than 50 em over the past year. In Big Lagoon, however, SAY has declined an average of 10 em in horizontal coverage along the deepwater edge. Water quality and photosynthetically active radiation light measurements from the Escambia-Pensacola Bay System suggest that increased light availability was associated with the increased seagrass coverage in Santa Rosa Sound and Pensacola Bay, and elevated nutrient concentrations were associated with the seagrass declines in Big Lagoon
Preliminary Survey of Chemical Contaminants in Water, Sediment, and Aquatic Biota at Selected Sites in Northeastern Florida Bay and Canal C-111
Several actions are under way to alter water management capabilities and practices in south Florida in order to restore a more natural hydroperiod for the Everglades. Because relatively little research has been conducted on contaminants entering Florida Bay, we undertook a preliminary study in June 1995 to determine contaminant concentrations in surface water, sediment, and biota prior to major changes in water management. The areas studied were the C-111 canal (five sites) beginning just above water control structure S-197 and extending to Manatee Bay (part of the Biscayne Bay system), Shell Creek (three sites), the mouth of Taylor River, Trout Creek (two sites), and a site near the Key Largo Ranger Station. Hydrographic observations were made at each site, and samples of water and sediment were collected at each of the five areas except the Key Largo site. Bioresidues were determined for indigenous oysters collected from the C-111 canal and Shell Creek and for transplanted oysters exposed at the Key Largo site, the C-111 canal, Shell Creek, Taylor River, and Trout Creek for 5-29 days. Water samples were analyzed for selected organochlorine pesticides and metals; sediments were analyzed for the same compounds and for polycyclic aromatic hydrocarbons (PAHs). Fish filets and shucked oysters were analyzed for selected organochlorine pesticides, polychlorinated biphenyl (PCB) congeners, and metals. Other than low dissolved oxygen at some C-111 canal sites, water quality was generally good. Most contaminants were below water and sediment quality guidelines designed to protect aquatic life, and contaminant concentrations in oysters were low. Threshold effect levels were exceeded for some organochlorine pesticides and PAHs in some sediment samples, but all values measured were below probable effect levels. Low concentrations of organochlorine pesticides were detected in sediments from the C-111 canal, Shell Creek, Taylor River, and Trout Creek; except for Taylor River, low concentrations of PCB congeners and PAHs were detected from the same areas. The only organochlorine pesticide detected in filets from seven fish was 3.2 v-g DDE/kg (wet weight) in a sea catfish. Total mercury concentrations in filets of four species of fishes ranged from 0.53 to 1.3 ÎĽg/g, wet weight, which falls within a limited consumption advisory by the State of Florida
Siglec-F is a novel intestinal M cell marker
Intestinal microfold (M) cells are epithelial cells primarily present on Peyer's patches (PPs) in the small intestine. The ability of M cells to shuttle antigens into the PP for appropriate immune responses makes M cells a target for next-generation oral vaccine delivery. In this regard, discovery of M cell specific receptors are of great interest, which could act as molecular tags for targeted delivery of cargo to M cells. Here, using a monoclonal antibody we generated to the Sialic acid-binding immunoglobulin-like lectin F (Siglec-F), we show that Siglec-F is expressed on mouse M cells in the small intestine. Immunohistochemical analysis of the PP tissue sections shows that Siglec-F is expressed on the surface of the M cell membrane exposed to the intestinal lumen. Anti-Siglec-F antibody injected into the mouse small intestine bound to M-cells, demonstrating the potential to target M cells via Siglec-F
Bostonia: 1993-1994, no. 2-3
Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs
A megaplasmid family driving dissemination of multidrug resistance in Pseudomonas.
Multidrug resistance (MDR) represents a global threat to health. Here, we used whole genome sequencing to characterise Pseudomonas aeruginosa MDR clinical isolates from a hospital in Thailand. Using long-read sequence data we obtained complete sequences of two closely related megaplasmids (>420 kb) carrying large arrays of antibiotic resistance genes located in discrete, complex and dynamic resistance regions, and revealing evidence of extensive duplication and recombination events. A comprehensive pangenomic and phylogenomic analysis indicates that: 1) these large plasmids comprise an emerging family present in different members of the Pseudomonas genus, and associated with multiple sources (geographical, clinical or environmental); 2) the megaplasmids encode diverse niche-adaptive accessory traits, including multidrug resistance; 3) the accessory genome of the megaplasmid family is highly flexible and diverse. The history of the megaplasmid family, inferred from our analysis of the available database, suggests that members carrying multiple resistance genes date back to at least the 1970s
State and specific growth estimation in heterologous protein production by Pichia pastoris
The productivity of an industrial fermentation
process involving a filamentous microbe is heavily dependent
on the morphological form adopted by the organism.
The development of systems capable of rapidly and accurately
characterizing morphology within a given process
represents a significant challenge, as the complex phenotypes
that are manifested are not easily quantified. Conventional
parameters employed in these analyses are often of limited
value, as they reveal little about the branching behavior of
the organism; an important consideration given the demonstrated
link between branching frequency and metabolite
production. In this study, the influence of branching behavior
on the spatial distribution of mycelia grown in silico is
examined through fractal analysis. It is demonstrated that
fractal dimension, quantified based on the frequency distribution
of parameterized boundary curves, and lacunarity act
as robust estimators of branching behavior. The analysis can,
in theory, be applied to any morphological form, providing
universally applicable process parameters for more complete
data acquisition.This work was supported by a grant from the Spanish programme of Chemical Processes Technologies (CTQ2007-60347; CTQ2010-15131), HP2007-0045 from Science and Innovation Ministry, 2009-SGR-00281 and the Reference Network in Biotechnology (XRB) from the DURSI (Generalitat de Catalunya). Support from "Luso-Spanish Integrated Actions" (Action 100/08) are also acknowledged. JMB would like to thank the Spanish Education Ministry for his predoctoral fellowship
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