Odor Characterization at Open-Lot Beef Cattle Feedyards Using Triangular Forced-Choice Olfactometry

Odor is a growing concern at concentrated animal feeding operations as residential houses encroach upon rural areas once occupied only by agriculture. A research project was conducted to determine baseline ambient odor characteristics at large open-lot beef cattle feedyards and to develop a better understanding of when and why odors occur at feedyards. Ambient odor samples were collected two to four times per month over a 12-month period in 2002-2003 at three large commercial open-lot beef cattle feedyards in the Texas panhandle. Ambient odor samples were collected upwind of the feedyard, downwind of the pens, and downwind of the runoff storage pond. Odor samples were also collected on five separate days covering four months in 2004 from a surface isolation flux chamber to estimate odor emission rates from the feedyard surface. All odor samples were collected in 10 L Tedlar bags and analyzed with trained human odor panelists for odor concentration (detection threshold, DT) by dynamic dilution forced-choice olfactometry, intensity by reference scaling, and hedonic tone. Manure moisture content and weather data were collected on-site at each of the feedyards. At two of the feedyards, mean DTs downwind of the pens and storage pond were statistically similar to upwind DTs, ranging from 33 to 45 OU m-3. At the third feedyard, mean DTs downwind of the pens (69 OU m-3) and pond (124 OU m-3) were statistically higher than the mean upwind DT (36 OU m-3) (p \u3c 0.05). Odor emission rates ranged from 0.3 to 3.2 OU m-2 s-1 during a period when downwind DTs ranged from 17 to 132 OU m-3. A number of elevated DTs were explained by elevated manure moisture contents from recent precipitation. These results demonstrate that odor production from open-lot beef cattle feedyards is a complex phenomenon that depends at least partially on weather conditions. Thus, odor prediction and control will likely be difficult at these facilities

On Two-Path Convexity in Multipartite Tournaments

Abstract In the context of two-path convexity, we study the rank, Helly number, Radon number, Caratheodory number, and hull number for multipartite tournaments. We show the maximum Caratheodory number of a multipartite tournament is 3. We then derive tight upper bounds for rank in both general multipartite tournaments and clone-free multipartite tournaments. We show that these same tight upper bounds hold for the Helly number, Radon number, and hull number. We classify all clone-free multipartite tournaments of maximum Helly number, Radon number, hull number, and rank. Finally we determine all convexly independent sets of clone-free multipartite tournaments of maximum rank

Extending Working Lives: A Systematic Review of Healthy Working Life Expectancy at Age 50

Retirement ages for receipt of state/social pensions are rising in many countries in response to population ageing and increasing life expectancy. However, sickness absence and early retirement for health reasons (especially among adults aged?=?50) present challenges to this. Estimates of the average number of years people are both healthy and in work from age 50 are needed to inform policy making and assess the feasibility of policy changes. A systematic review was carried out to identify existing population indicators, and estimates, of life expectancy in health and work. Nine databases were systematically searched on the 30th January 2019. Eligible papers were identified using inclusion/exclusion criteria. Evidence synthesis was undertaken to explore indicators and estimates. Four studies were included for review from 1485 identified by the search. A narrative review was carried out; quantitative pooling of the results was not feasible due to high heterogeneity between studies. All estimates of the average number of years spent in both health and work from age 50 were below 10 years with the exception of a population subgroup of Finnish male executives (11.91 years). The review indicated that population indicators of health and work that could estimate the average number of years people are healthy and in work are rarely used, and that there are no current and reliable estimates. One indicator, Healthy Working Life Expectancy (measuring life expectancy in health and work from age 50), offers the potential to be a suitable measure for monitoring life expectancy in health and work

Reassessing the origin of Triton

Agnor & Hamilton (2006) demonstrated that the disruption of a binary was an effective mechanism to capture Triton. The subsequent evolution of Triton's post-capture orbit could have proceeded through gravitational tides. The study by Agnor & Hamilton (2006) is repeated in the framework of the Nice model to determine the post-capture orbit of Triton. After capture it is then subjected to tidal evolution. The perturbations from the Sun and the figure of Neptune are included. The perturbations from the Sun acting on Triton cause it to spend a long time in its high-eccentricity phase, usually of the order of 10 Myr, while the typical time to circularise to its current orbit is some 200 Myr. The current orbit of Triton is consistent with an origin through binary capture and tidal evolution, even though the model prefers Triton to be closer to Neptune than it is today. The probability of capturing Triton in this manner is approximately 0.7%. Since the capture of Triton was at most a 50% event -- since only Neptune has one, but Uranus does not -- we deduce that in the primordial trans-Neptunian disc there were 100 binaries with at least one Triton-sized member. Morbidelli et al. (2009) concludes there were some 1000 Triton-sized bodies in the trans-Neptunian proto-planetary disc, so the primordial binary fraction with at least one Triton-sized member is 10%. This value is consistent with theoretical predictions, but at the low end. If Triton was captured at the same time as Neptune's irregular satellites, the far majority of these, including Nereid, would be lost. This suggests either that Triton was captured on an orbit with a small semi-major axis a < 50 R_N (a rare event), or that it was captured before the dynamical instability of the Nice model, or that some other mechanism was at play. The issue of keeping the irregular satellites remains unresolved.Comment: Accepted in Icarus 201

Prospectus, December 14, 1983

MERRY CHRISTMAS TO ALL; Memories recalled from Christmases past; 32 are named in Who\u27s Who; News Digest; Parkland student talks with Santa; Simpson keeps position; Illinois joins no-fault divorce movement; PC Happenings: Second blood drive is success; German club goes to Chicago; Rotary scholarships available; Camera ban lifted; Final Exam Schedule; Looking forward to a winter like last year\u27s!; Parkland publishes annual magazine--Intercom; Zamary decorates cakes; Letter to the editor; Christmas carols are important part of world history; Letter to the editor; Question: When did you stop believing in Santa?; Question: What was the best Christmas gift you ever received?; Question: What is your best Christmas memory or tradition?; Christmas--ancient celebration of the birth of Christ; Spring brings more of an abundance of Cabbage Patches; The brighter side of Christmas; Make holiday cleaning easy; Tips for easier Holiday Baking; Tree trimming is art; Christmas cards originate in England; Recipes for Christmas and New Years; Christmas of yesteryear at the Lake of the Woods; Parkland before the brown brick campus; Photographer captures old-fashioned Christmas; Wham Bam it\u27s Tieken man and U.R.S.A..; Pulitzer winner at Krannert; WILL--most varied holiday line-up; Variety of films hits the 1983 Christmas season; Dylan is back again; \u27Stones\u27 come back to life; January Krannert Schedule; Classifieds; Tips on how to stay out of an accident on icy days; 1984 Bowl game schedule; Cobra volleyball players feted; Composite Athletic Schedule; I.M. News...; Women win; Track tream ready for season; Fire hazard safety tips; Local search for Opryland talent; President\u27s Christmas messagehttps://spark.parkland.edu/prospectus_1983/1000/thumbnail.jp

Oxidative Stress Mediates Physiological Costs of Begging in Magpie (Pica pica) Nestlings

[Background] Theoretical models predict that a cost is necessary to guarantee honesty in begging displays given by offspring to solicit food from their parents. There is evidence for begging costs in the form of a reduced growth rate and immunocompetence. Moreover, begging implies vigorous physical activity and attentiveness, which should increase metabolism and thus the releasing of pro-oxidant substances. Consequently, we predict that soliciting offspring incur a cost in terms of oxidative stress, and growth rate and immune response (processes that generate pro-oxidants substances) are reduced in order to maintain oxidative balance. [Methodology/Principal Findings] We test whether magpie (Pica pica) nestlings incur a cost in terms of oxidative stress when experimentally forced to beg intensively, and whether oxidative balance is maintained by reducing growth rate and immune response. Our results show that begging provokes oxidative stress, and that nestlings begging for longer bouts reduce growth and immune response, thereby maintaining their oxidative status. [Conclusions/Significance] These findings help explaining the physiological link between begging and its associated growth and immunocompetence costs, which seems to be mediated by oxidative stress. Our study is a unique example of the complex relationships between the intensity of a communicative display (begging), oxidative stress, and life-history traits directly linked to viability.GM-R was supported by the Spanish Government (Ministerio de Ciencia y Tecnología, “Juan de la Cierva” program), and TR was supported by the Consejo Superior de Investigaciones Científicas (CSIC; Proyectos Intramurales Especiales)

California annual grass invaders: the drivers or passengers of change?

The dominance of invasive species is often assumed to reflect their competitive superiority over displaced native species. However, invasive species may be abundant because of their greater tolerance to anthropogenic impacts accompanying their introduction. Thus, invasive species can either be the drivers or passengers of change.We distinguish between these two possibilities in California grasslands currently dominated by Mediterranean annuals (exotics) and subjected to livestock grazing since European settlement. We focused on native annual grasses and forbs, an understudied species-rich component of the California flora, and Mediterranean annual grasses, currently dominant and among the first non-native plants introduced to the area.We established a field experiment with fenced and unfenced blocks in a cattle pasture. We measured concentrations of limiting resources (nitrogen, phosphorus, light and soil moisture) in monoculture plots as an index of competitive ability (i.e. R*). We then quantified grazing impacts on biomass and seed production in grazed vs. ungrazed monoculture plots. Finally, we measured biomass and seed production of each species competing in mixture plots, in the presence and absence of grazers.We found that native and exotic species did not differ in R* indices of competitive ability, i.e. concentrations of limiting resources in ungrazed native monoculture plots did not differ from concentrations in ungrazed exotic monoculture plots. By contrast, exotic annuals suffered less from grazing than native annuals, perhaps reflecting their longer evolutionary history with cattle grazing. Consistent with these results, native and exotic annuals were equally abundant in ungrazed mixtures, but exotic species overwhelmingly dominated grazed mixtures.Species able to draw down nitrogen and light to lower levels in monocultures (i.e. those with lower R* values) dominated biomass and seeds in mixed plots without grazers. However, R* did not predict the relative abundance of species in grazed plots. Moreover, the relative abundance of species in mixtures did not correlate with grazing impacts on their monocultures, implying that grazing alters inter-specific competitive dynamics.Synthesis. We demonstrate that the displacement of native annuals by Mediterranean annual grasses in California may largely have been driven by cattle grazing

Dpp Signaling Activity Requires Pentagone to Scale with Tissue Size in the Growing Drosophila Wing Imaginal Disc

The activity of the Dpp morphogen adapts to tissue size in the growing Drosophila wing imaginal disc, and Pentagone, an important secreted feedback regulator of the Dpp pathway, is required for this adaptation