3,524 research outputs found
Discrimination and Quantification of Glomerular Receptor Subtypes for Atrial Natriuretic Factor (Anf)
Binding sites for atrial natriuretic factor (ANF) were determined on isolated rat glomeruli as well as on glomerular membranes. To define optimal conditions, binding of ANF was investigated varying incubation time, temperature and protein concentration. Binding conditions were found to be best at 4°C for 5 hours with 15 Όg of glomerular protein. Saturation and affinity cross-linking experiments confirmed the presence of two distinct receptor subtypes - the B-receptor (130 kDa) and the C-receptor (65 kDa). Quantitative differentiation of both ANF binding sites was achieved by competitive displacement with two different unlabeled ANF ligands: a) rANF(99-126) (homologous displacement), b) des(18-22)rANF(4-23)NH2(heterologous displacement). Intact glomeruli and glomerular membranes did not differ significantly in receptor density for the B-receptor (71 ± 37 vs. 94 ± 53 fmol/mg protein) or the C-receptor (976 ± 282 vs. 966 ± 167 fmol/mg protein) or in affinity constants for the B-receptor (43 ± 36 vs. 52 ± 44 pM) or the C-receptor (876 ± 377 vs. 307 ± 36 pM). Glomerular membranes compared to glomeruli showed less nonspecific binding and less intra-assay variation of measuring points done in triplicates. This method of selective displacement should allow to study the influence of various physiological and pathophysiological conditions on the binding properties of B-and C-receptors for ANF
Knowledge tree: Putting discourse into computerâbased learning
Most CBL materials currently in use model only the declarative aspects of the learning process. If such courseware is used without careful planning, this can be dangerous because one of the most fundamental aspects of education is the dialogue that occurs between teachers and the students. Traditionally, this has taken place in informal discussions as well as in formal smallâgroup learning sessions such as the conventional tutorial. However, as the studentâstaff ratio increases, so does the opportunity for this type of personal dialogue decrease. Modern networking technology offers a huge potential to add discourse to CBL, but there are many pedagogical problems involved with the intrinsically ephemeral and anarchic nature both of the Internet and of most conferencing or bulletinâboard systems. In this paper we describe a software system called Knowledge Tree (KT) which we have developed to address some of these issues. KT combines a hierarchical conceptâoriented database functionality with that of a Usenetâstyle bulletin board Using this, a knowledge garden may be developed for any subject area. These each contain a hypermedia database of frequently asked questions, together with answers provided by subject experts. There is provision for interâstudent discussions of problems and issues. When students ask new questions these are automatically emailed to a relevant subject expert (determined by a subjectâspecific concept thesaurus). The answer is then placed in the database which eventually grows to become a valuable teaching resource. KT is disciplineâindependent as the concept thesaurus can be changed to encapsulate any domain of knowledge. We have used it in support of conventional lecture courses, as an important component of a multimedia course, and for general IT support. These examples illustrate the role that this system can play both in basic information provision, and in facilitating the discussion of deep issues
Potential use of offshore marine structures in rebuilding an overfished rockfish species, bocaccio (Sebastes paucispinis)
Although bocaccio (Sebastes paucispinis) was an economically important rockfish species along the west coast of North America, overfishing has reduced the stock to about 7.4% of its former unfished population. In 2003, using a manned research submersible, we conducted fish surveys around eight oil and gas platforms off southern California as part of an assessment of the potential value of these structures as fish habitat. From these surveys, we estimated that there was a minimum of 430,000 juvenile bocaccio at these eight structures. We determined this number to be about 20% of the average number of juvenile bocaccio that survive annually for the geographic range of the species. When these juveniles become adults, they will contribute about one percent (0.8%) of the additional amount of fish needed to rebuild the Pacific Coast population. By comparison, juvenile bocaccio recruitment to nearshore natural nursery grounds, as determined through regional scuba surveys, was low in the same year. This research demonstrates that a relatively small amount of artificial nursery habitat may be quite valuable in rebuilding an overfished species
Search Tool Implementation for Historical Archive
Dr. Linda Arnold's archival project "Mexican-American War and the Media" is an underutilized resource. Providing contrasting primary sources on the War, it is the only archive of its kind. In order to make the archive's massive amount of information more accessible to researchers and students, I added search functionality to the site. Several tools were implemented and tested. Perlfect, a Perl-based open-source approach, was determined to be the best option. This report includes an outline of the steps taken to implement the search tool, a user's manual, a developer's manual, and options for future work. The archive may be accessed at http://www.majbill.vt.edu/history/mxamwar/index.htm
The Legacy of the Glacier Priest : Bernard R. Hubbard, S.J.
One of the most colorful and controversial individuals to bring notoriety to Santa Clara University in the past 150 years was Father Bernard R. Hubbard, S.J.(1888-1962). Known as the Glacier Priest, for his mountaineering prowess , Father Hubbard gained public prominence in the 1930s for his highly publicized and photographed expeditions to the then little known territory of Alaska. In an era without television and the internet, the public\u27s imagination was captured through public lectures and newsreels. In spite of his larger than life public persona Father Hubbard\u27s relationship with his professional colleagues and the Society of Jesus was sometimes less than ideal when it came to scholarly and educational goals. Perhaps this is best underscored by the fact that following his death in 1962 an exhibit on the Santa Clara University campus on his Alaskan expeditions was closed and dismantled. As the readers of this volume will find, the scholars of the 1960s and 1970s continued to see his documentaries as little more than newsreel filler. Now, as we enter a new century, a new generation of scholars and descendants are finding Hubbard\u27s film and photographic legacy to be the only documentation of a way of life that ceased to exist a half a century ago
Solubility studies of ultra pure transition elements in ultra pure alkali metals
Solubility of pure iron, molybdenum, niobium, and tantalum in liquid potassiu
Should nutrient profile models be âcategory specific' or âacross-the-board'? A comparison of the two systems using diets of British adults
Background/Objectives: Nutrient profile models have the potential to help promote healthier diets. Some models treat all foods equally (across-the-board), some consider different categories of food separately (category specific). This paper assesses whether across-the-board or category-specific nutrient profile models are more appropriate tools for improving diets. Subjects/Methods: Adult respondents to a British dietary survey were split into four groups using a diet quality index. Fifteen food categories were identified. A nutrient profile model provided a measure of the healthiness of all foods consumed. The four diet quality groups were compared for differences in (a) the calories consumed from each food category and (b) the healthiness of foods consumed in each category. Evidence of a healthier diet quality groups consuming more of healthy food categories than unhealthy diet quality groups supported the adoption of across-the-board nutrient profile models. Evidence of healthier diet quality groups consuming healthier versions of foods within food categories supported adoption of category-specific nutrient profile models. Results: A significantly greater percentage of the healthiest diet quality group's diet consisted of fruit and vegetables (21 vs 16%), fish (3 vs 2%) and breakfast cereals (7 vs 2%), and significantly less meat and meat products (7 vs 14%) than the least healthy diet quality group. The foods from the meat, dairy and cereals categories consumed by the healthy diet quality groups were healthier versions than those consumed by the unhealthy diet quality groups. Conclusions: All other things being equal, nutrient profile models designed to promote an achievable healthy diet should be category specific but with a limited number of categories. However models which use large number of categories are unhelpful for promoting a healthy diet
Leadership during a racial microaggression on campus
The study aimed at understanding studentsâ perspectives on university response to a racial microaggression on a campus. Responses were collected in the form of an online survey and analyzed using qualitative data analysis to identify themes from studentsâ perspective. Insights about how students processed the incident were gained. Although students were thankful of the university response, concern for another incident, and how leadership will equip students to handle situations lingers. Implications for educators are provided
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Simulating the impact on health of internalising the cost of carbon in food prices combined with a tax on sugar-sweetened beverages
Rising greenhouse gas emissions (GHGEs) have implications for health and up to 30 % of emissions globally are thought to arise from agriculture. Synergies exist between diets low in GHGEs and health however some foods have the opposite relationship, such as sugar production being a relatively low source of GHGEs. In order to address this and to further characterise a healthy sustainable diet, we model the effect on UK non-communicable disease mortality and GHGEs of internalising the social cost of carbon into the price of food alongside a 20 % tax on sugar sweetened beverages (SSBs).
Developing previously published work, we simulate four tax scenarios: (A) a GHGEs tax of ÂŁ2.86/tonne of CO2 equivalents (tCO2e)/100 g product on all products with emissions greater than the mean across all food groups (0.36 kgCO2e/100 g); (B) scenario A but with subsidies on foods with emissions lower than 0.36 kgCO2e/100 g such that the effect is revenue neutral; (C) scenario A but with a 20 % sales tax on SSBs; (D) scenario B but with a 20 % sales tax on SSBs. An almost ideal demand system is used to estimate price elasticities and a comparative risk assessment model is used to estimate changes to non-communicable disease mortality.
We estimate that scenario A would lead to 300 deaths delayed or averted, 18,900 ktCO2e fewer GHGEs, and ÂŁ3.0 billion tax revenue; scenario B, 90 deaths delayed or averted and 17,100 ktCO2e fewer GHGEs; scenario C, 1,200 deaths delayed or averted, 18,500 ktCO2e fewer GHGEs, and ÂŁ3.4 billion revenue; and scenario D, 2,000 deaths delayed or averted and 16,500 ktCO2e fewer GHGEs. Deaths averted are mainly due to increased fibre and reduced fat consumption; a SSB tax reduces SSB and sugar consumption.
Incorporating the social cost of carbon into the price of food has the potential to improve health, reduce GHGEs, and raise revenue. The simple addition of a tax on SSBs can mitigate negative health consequences arising from sugar being low in GHGEs. Further conflicts remain, including increased consumption of unhealthy foods such as cakes and nutrients such as salt
Identical Response of Caged Rock Crabs (Genera Metacarcinus and Cancer) to Energized and Unenergized Undersea Power Cables in Southern California, USA
Energy generation facilities (i.e., wave and wind) are being sited in offshore marine waters. The electricity generated from these facilities is transmitted to shore through cables carrying alternating or direct current. This current produces an electromagnetic field (EMF) that is emitted from the cable. Concerns have been voiced regarding how marine organisms, in this instance crabs, respond to the EMF emitted by submarine power cables. Two submarine cables, one energized and the other unenergized, and separated by about 7 m, were used in the experiment. Crabs (Metacarcinus anthonyi (Rathbun, 1897) and Cancer productus (Randall, 1839)) were placed in plastic perforated boxes secured to the sea floor with one end in contact with one of the two cables. After one hour and 24 hours, scuba divers ascertained the position of the crabs within the boxes, these positions designated as either ânear-halfâ or âfar-half.â EMF readings were taken on the floor of each box at the edge closest to the cable and on the floor of that box furthest from the cable at one and 24 hours. Within the boxes, EMF levels were between 46.2â80.0 microteslas next to the cable an
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