Absorption and release of carbon monoxide by C3 and C4 turfgrasses in light and dark

Carbon monoxide (CO) is a colorless, odorless gas that can be harmful to humans at a relatively low level (Stewart, 1975). The ambient concentration of CO in the atmosphere is estimated to be 0.04 to 0.90 ul/liter (Robbins et al. 1968). In addition to this ambient CO concentration, the estimated world-wide emissions of CO from anthropogenic sources is 200 X 10 6 metric tons/year (Robbins et al. 1968)

Incentives and ratcheting in a multiproduct firm: a field experiment

We develop a model and derive behavioral predictions for a multiproduct sales force subject to goals set based on past performance. We test these predictions using a field experiment in which 53 salespersons from a Chilean beverage company face exogenous variations in monthly sales goals. Confirming our predictions, we found that (1) absent strategic considerations—no goal ratcheting—salespersons increase (decrease) sales in the product category for which the return to effort increases (decreases), (2) including strategic considerations behavior reverses: salespersons who expect high goal ratcheting decrease (increase) sales in the category for which the return to effort increases (decreases), (3) sales did not change for the average salespersons, reflecting heterogeneity in the expectations of goal ratcheting rather than unresponsiveness to incentives. Our study points at the importance of the dynamics of incentive design, in particular, the importance of understanding the dynamics of goal setting in firms

Shaping Communities Through Extension Programs

A community\u27s essence, which is the combination of its identity, purpose, and culture, is dynamic. It is influenced or shaped in part by what the community knows. Extension, through its educational programs, plays a large part in creating community knowledge. This article shows how Extension educators can extend and accelerate the community-shaping process by using action research processes like Appreciative Inquiry. It also describes the Porch Cookie Project, one adaptation of Appreciative Inquiry

Can firms be both broad and deep? Exploring interdependencies between horizontal and vertical firm scope

Firms can be horizontally diversified, with considerable breadth, or vertically integrated, with great depth. This study explores how breadth and depth affect each other as influenced by capability requirements and coordination demands. Using construction industry data, we assess the interdependence between contractors’ portfolios of building types (horizontal scope) and the extent of integration of the activities needed to complete each project (vertical scope). We find that vertical and horizontal scope have a negative interdependency only when contractors face managerial constraints due to coordination challenges. Further, we show that this effect can be mitigated through organizational structures that centralize key functions. Our findings highlight the importance of coordination in the theory of the firm, as we link firm boundaries to managerial coordination and internal organization

Kepler-539: a young extrasolar system with two giant planets on wide orbits and in gravitational interaction

We confirm the planetary nature of Kepler-539b (aka Kepler object of interest K00372.01), a giant transiting exoplanet orbiting a solar-analogue G2 V star. The mass of Kepler-539b was accurately derived thanks to a series of precise radial velocity measurements obtained with the CAFE spectrograph mounted on the CAHA 2.2m telescope. A simultaneous fit of the radial-velocity data and Kepler photometry revealed that Kepler-539b is a dense Jupiter-like planet with a mass of Mp = 0.97 Mjup and a radius of Rp = 0.747 Rjup, making a complete circular revolution around its parent star in 125.6 days. The semi-major axis of the orbit is roughly 0.5 au, implying that the planet is at roughly 0.45 au from the habitable zone. By analysing the mid-transit times of the 12 transit events of Kepler-539b recorded by the Kepler spacecraft, we found a clear modulated transit time variation (TTV), which is attributable to the presence of a planet c in a wider orbit. The few timings available do not allow us to precisely estimate the properties of Kepler-539c and our analysis suggests that it has a mass between 1.2 and 3.6 Mjup, revolving on a very eccentric orbit (0.4<e<0.6) with a period larger than 1000 days. The high eccentricity of planet c is the probable cause of the TTV modulation of planet b. The analysis of the CAFE spectra revealed a relatively high photospheric lithium content, A(Li)=2.48 dex, which, together with both a gyrochronological and isochronal analysis, suggests that the parent star is relatively young.Comment: 11 pages, 14 figures, accepted for publication in Astronomy & Astrophysic

An eccentric companion at the edge of the brown dwarf desert orbiting the 2.4 Msun giant star HIP67537

We report the discovery of a substellar companion around the giant star HIP67537. Based on precision radial velocity measurements from CHIRON and FEROS high-resolution spectroscopic data, we derived the following orbital elements for HIP67537$\,b$: m$_b$sin$i$ = 11.1$^{+0.4}_{-1.1}$ M$_{\rm {\tiny jup}}$, $a$ = 4.9$^{+0.14}_{-0.13}$ AU and $e$ = 0.59$^{+0.05}_{-0.02}$. Considering random inclination angles, this object has $\gtrsim$ 65% probability to be above the theoretical deuterium-burning limit, thus it is one of the few known objects in the planet to brown-dwarf transition region. In addition, we analyzed the Hipparcos astrometric data of this star, from which we derived a minimum inclination angle for the companion of $\sim$ 2 deg. This value corresponds to an upper mass limit of $\sim$ 0.3 M$_\odot$, therefore the probability that HIP67537$\,b$ is stellar in nature is $\lesssim$ 7%. The large mass of the host star and the high orbital eccentricity makes HIP67537$\,b$ a very interesting and rare substellar object. This is the second candidate companion in the brown dwarf desert detected in the sample of intermediate-mass stars targeted by the EXPRESS radial velocity program, which corresponds to a detection fraction of $f$ = 1.6$^{+2.0}_{-0.5}$%. This value is larger than the fraction observed in solar-type stars, providing new observational evidence of an enhanced formation efficiency of massive substellar companions in massive disks. Finally, we speculate about different formation channels for this object.Comment: Accepted for publication to A&