The Capitalization of Seller Paid Consessions

Using a hedonic pricing model, we analyze the capitalization of total seller paid discount points and closing costs into the price of a house. We hypothesize that sellers are concerned about the sales price net of total seller paid concessions (SPNC), rather than the exact terms of the transaction. Since the SPNC is easily ascertained in the negotiation process, we further hypothesize that total seller paid concessions (TSPC) are fully capitalized into the sales price. To test this hypothesis, sales price is regressed on a set of control variables including TSPC. In this framework, TSPC will be positive and not significantly different from one if concessions are fully capitalized. The empirical results provide support for the capitalization hypothesis. Negotiation strategies and study limitations follow from the empirical results.

The role of sexual reproduction in the maintenance of established Zostera marina meadows

For clonal plants, the role of sexual reproduction in the maintenance of populations can vary widely. Some species are dependent on repeated seedling recruitment. For other species, interactions between adults and seedlings within existing populations can affect seedling survival and limit sexual reproduction in existing populations. Genetic studies of seagrass populations increasingly suggest sexual reproduction is important for the resilience and stability of their populations, but as of yet little observational data support these findings. Because seagrass populations provide important ecosystem services and are threatened with increasing anthropogenic impacts, understanding their reliance on sexual reproduction is evolutionarily and ecologically important. The goals of this study were to determine (a) whether seedlings of a marine angiosperm, Zostera marina, establish and recruit within existing Z. marina meadows and (b) whether interactions between seedlings and surrounding adult shoots influence the survival of established seedlings. To meet these goals, surveys estimated seedling establishment and tracked seedling survival within multiple populations. Manipulative experiments then tested the impact of neighbouring adult shoots on seedling survival and the overall trajectory of experimental plots with and without sexual reproduction. A 3‐year survey identified established seedlings within Z. marina meadows each year. Additionally, concurrent seed addition experiments indicated seed supply could influence seedling establishment rates. A survey tracking the survival of tagged seedlings, as well as the height and density of surrounding adult shoots, showed adult shoots may negatively impact seedling survival. Experiments then demonstrated that seedlings without neighbouring shoots survived longer than those with neighbouring shoots. Lastly, two transplant garden experiments comparing the survival of plots with and without seeds highlighted that seedling recruitment is likely most important to maintain bottom cover where disturbances generate gaps in the adult population. Synthesis. This study demonstrates that seedlings do establish within existing seagrass meadows, and that some survive to recruit into the adult population. Competition with existing vegetation, however, can be a factor compromising seedling survival. Sexual reproduction may thus most likely occur in, and be most important for, clonal plant populations that experience seasonal disturbance

Herbivory regulates the establishment of a native species of submerged aquatic vegetation (SAV) in a tidal estuary of the USA

Herbivores are a diverse group of fauna that shape the distribution and composition of plant communities. In some cases, herbivory may prevent the re-establishment of submerged aquatic vegetation (SAV), such as Vallisneria americana, into systems. The goal of this study was to investigate the role and nature of herbivory on V. americana transplants with camera and transect surveys of grazing intensity and with field and laboratory grazing experiments using a suspected herbivore, the blue crab, Callinectes sapidus. Camera surveys recorded C. sapidus clipping and consuming shoots of V. americana for the first time. Grazing intensity surveys in low-salinity regions of the lower Chesapeake Bay indicated that the majority of V. americana transplants (50–75%) were clipped off at their base within one week of planting. Field and laboratory experiments demonstrated that C. sapidus clips and consumes V. americana as well as other rapidly colonizing, non-native SAV. Analysis of the gut contents of C. sapidus caught in SAV beds in the Chesapeake Bay revealed that SAV comprised 16% of their stomach contents, suggesting low levels of C. sapidus herbivory occurred over a wide area. Callinectes sapidus is yet another animal documented to consume SAV for some portion of their diet. These results also suggest that herbivores or omnivores, including C. sapidus, can serve as bottlenecks to recovery of SAV, like V. americana, in some areas. Herbivores may not serve as bottlenecks in other environments or to other SAV with more rapid plant growth or higher recruitment levels that may overcome grazing pressure

Heavy Winter Patch Grazing as an Alternative to Prescribed Burning on the Northern Great Plains

Among management systems intended to increase heterogeneity on the landscape, patch burn grazing (PBG) is by far the most prominent and researched method. Though prescribed burning is seen as a healthy disturbance in grassland ecosystems, many landowners in the Northern Great Plains have an aversion to fire. This is due to safety and liability concerns as well as concerns over forage losses and limitations of labor, equipment, and insurance to successfully carry out prescribed burns. Therefore, there is a critical need to evaluate alternative, non-fire management strategies that will encourage rangeland heterogeneity. A study was conducted in 2017-2018 at the Cottonwood Field Station in southwest South Dakota to test the effectiveness of heavy winter patch grazing to simulate fire. The objectives of this study were to determine the extent to which WPG can serve as an alternative management strategy to patch burn grazing to 1) increase vegetation structural heterogeneity and 2) alter livestock grazing behavior to maintain structural heterogeneity through time

Simulation, modelling and development of the metris RCA

In partnership with Metris UK we discuss the utilisation of modelling and simulation methods in the development of a revolutionary 7-axis Robot CMM Arm (RCA). An offline virtual model is described, facilitating pre-emptive collision avoidance and assessment of optimal placement of the RCA relative to scan specimens. Workspace accessibility of the RCA is examined under a range of geometrical assumptions and we discuss the effects of arbitrary offsets resulting from manufacturing tolerances. Degeneracy is identified in the number of ways a given pose may be attained and it is demonstrated how a simplified model may be exploited to solve the inverse kinematics problem of finding the “correct” set of joint angles. We demonstrate how the seventh axis may be utilised to avoid obstacles or otherwise awkward poses, giving the unit greater dexterity than traditional CMMs. The results of finite element analysis and static force modelling on the RCA are presented which provide an estimate of the forces exerted on the internal measurement arm in a range of poses

Grazing Behavior, Forage Quality, and Intake Rates of Livestock Grazing Pastures Occupied by Prairie Dogs

Prairie dogs can reduce the carrying capacity on rangelands by up to 50% through direct consumption of vegetation and by clipping plants to improve predator detection. Studies have shown that forage quality and digestibility are greater on prairie dog towns than off-town, however research is lacking that quantifies rates of forage and nutrition intake by cattle grazing pastures occupied by prairie dogs. The objectives of this study were to 1) evaluate relationships between on- and off-town plant communities and cattle grazing locations to identify trends in livestock grazing behavior throughout the growing season, 2) evaluate diet nutrient composition and intake by cattle on plant communities on- and off-town over the grazing season, and 3) study livestock performance in response to level of prairie dog occupation within the pastures

Final Summary Report on Truck Route Access Evaluation

This report summarizes the evaluation of truck route access between the National Highway System and 46 truck generating sites, including intermodal sites, throughout Kentucky (includes 81 routes and 800 miles of highway). Routes were evaluated quantitatively for nine highway features, assigned an overall route rating and recommendations for routine maintenance and re-construction were made. The level and quality of truck access to the NHS varies dramatically throughout the state. Some facilities are between 25 and 50 miles from the NHS. No significant difference in route ratings or other measures was found by geographic location. The different typography throughout the state contributed to differences in grade and curvature quality. Very few non-NHS truck routes have 12-foot lanes along their whole length. The intermodal facility routes in general were found to be of better quality than routes leading to truck only sites. Trucks are not always using the routes they should. Ten of the routes were considered the best and required no improvements at this time. Improvements on other routes varied from routine maintenance to the need for complete reconstruction. Routes were prioritized by length and amount of truck traffic to recommend the most critical routes for improvement

MR446: Profiles of Sixteen Eastern Maine Fishing Communities

In the United States, a number of legal mandates require social impact assessments of proposed federal fisheries management and other actions. However, too often there are insufficient data with which to conduct social impact assessments for fisheries management, in part because these data are expensive and time consuming to collect and social science for SIAs is typically underfunded. To address this lack of data, these authors profiled 16 fish­ing communities in eastern Maine (Vinalhaven, Stonington, Bar Harbor, Northeast Harbor, Southwest Harbor, Bass Harbor, Swan’s Island, Steuben, Winter Harbor, Gouldsboro, Milbridge, Jonesport, Beals, Bucks Harbor, Lubec, and Eastport), focusing on the communities in eastern Maine currently or historically engaged in the New England groundfish fishery. The profiles are based on a rapid assessment to document the current infrastructure and updated with social, economic, and demographic data available from the 2010 U.S. Census and with 2011 state and federal license data.https://digitalcommons.library.umaine.edu/aes_miscreports/1026/thumbnail.jp

On the Anti-Correlation between Duration and Redshift in Gamma-ray Bursts

For gamma-ray bursts (GRBs) with durations greater than two seconds (so-called long GRBs), the intrinsic prompt gamma-ray emission appears, on average, to last longer for bursts at lower redshifts. We explore the nature of this duration-redshift anti-correlation, describing systems and conditions in which this cosmological evolution could arise. In particular, we explore its dependence on metallicity of a massive star progenitor, as we can securely count on the average stellar metallicity to increase with decreasing redshift. Although higher metallicity/lower redshift stars lose mass and angular momentum through line-driven winds, in some cases these stars are able to form more extended accretion disks when they collapse, potentially leading to longer duration GRBs. We also examine how this duration-redshift trend may show up in interacting binary models composed of a massive star and compact object companion, recently suggested to be the progenitors of radio bright GRBs. Under certain conditions, mass loss and equation of state effects from higher metallicity, lower redshift massive stars can decrease the binary separation. This can then lead to spin-up of the massive star and allow for a longer duration GRB upon the massive star's collapse. Finally, the duration-redshift trend may also be supported by a relatively larger population of small-separation binaries born in situ at low redshift.Comment: Accepted to Ap

4-aminopyridyl-based lead compounds targeting CYP51 prevent spontaneous parasite relapse in a chronic model and improve cardiac pathology in an acute model of Trypanosoma cruzi infection.

BackgroundChagas disease, caused by the protozoan Trypanosoma cruzi, is the leading cause of heart failure in Latin America. The clinical treatment of Chagas disease is limited to two 60 year-old drugs, nifurtimox and benznidazole, that have variable efficacy against different strains of the parasite and may lead to severe side effects. CYP51 is an enzyme in the sterol biosynthesis pathway that has been exploited for the development of therapeutics for fungal and parasitic infections. In a target-based drug discovery program guided by x-ray crystallography, we identified the 4-aminopyridyl-based series of CYP51 inhibitors as being efficacious versus T.cruzi in vitro; two of the most potent leads, 9 and 12, have now been evaluated for toxicity and efficacy in mice.Methodology/principal findingsBoth acute and chronic animal models infected with wild type or transgenic T. cruzi strains were evaluated. There was no evidence of toxicity in the 28-day dosing study of uninfected animals, as judged by the monitoring of multiple serum and histological parameters. In two acute models of Chagas disease, 9 and 12 drastically reduced parasitemia, increased survival of mice, and prevented liver and heart injury. None of the compounds produced long term sterile cure. In the less severe acute model using the transgenic CL-Brenner strain of T.cruzi, parasitemia relapsed upon drug withdrawal. In the chronic model, parasitemia fell to a background level and, as evidenced by the bioluminescence detection of T. cruzi expressing the red-shifted luciferase marker, mice remained negative for 4 weeks after drug withdrawal. Two immunosuppression cycles with cyclophosphamide were required to re-activate the parasites. Although no sterile cure was achieved, the suppression of parasitemia in acutely infected mice resulted in drastically reduced inflammation in the heart.Conclusions/significanceThe positive outcomes achieved in the absence of sterile cure suggest that the target product profile in anti-Chagasic drug discovery should be revised in favor of safe re-administration of the medication during the lifespan of a Chagas disease patient. A medication that reduces parasite burden may halt or slow progression of cardiomyopathy and therefore improve both life expectancy and quality of life