Model of molecular bonding based on the Bohr-Sommerfeld picture of atoms

We develop a model of molecular binding based on the Bohr-Sommerfeld description of atoms together with a constraint taken from conventional quantum mechanics. The model can describe the binding energy curves of H2, H3 and other molecules with striking accuracy. Our approach treats electrons as point particles with positions determined by extrema of an algebraic energy function. Our constrained model provides a physically appealing, accurate description of multi-electron chemical bonds.Comment: 5 pages, 7 figures, to appear in Physics Letters

Using the endowment effect to explain managerial resistance towards codetermination: implications for employment relations from the German case

This article provides an innovative defence of co-determination by way of exploring two of the most significant theorised objections to it from neo-liberal and libertarian perspectives, namely, the defence of the right to manage as freely chosen by employees and employers alike, and the right to manage being the most efficient, lowest transaction cost mode of employee governance. Instead, we focus upon management preference emanating from the endowment effect, and manifested in management style and ideology, as a more credible explanation for management’s support for its prerogative to manage. The endowment effect prompts both strong employer and manager objections to co-determination and weak employee willingness to seek it because humans place more value upon items currently in their possession than upon those they do not possess. We explore this argument by examining the experience of co-determination in Germany. The significance of our argument lies in identifying managerial preference as the key variable to be challenged and changed in order to pacify management opposition to co-determination through political, ideological and institutional means

Submergence times and abundance estimation of blue whales off Sri Lanka

Very little is known about the blue whale populations in the waters of Sri Lanka. A first attempt at estimating their relative abundances using DISTANCE sampling methods is currently underway in the waters off the southern coast of the island. Surfacing behavior was quantified from focal follows of individual blue whales between January and March 2011. Estimates of submergence times will be used for generating more precise abundance estimates. Individuals were followed from a 32-foot vessel to observe surfacing patterns and breathing behaviour in the presence and absence of whalewatching boats. Time at first surface, length of surface interval, number of blows and final dive time were collected. The data gathered was analysed using a hidden Markov model (HMM) to identify whether dive duration was uniform or whether dives could be classified using surface interval and submergence time. The preliminary results show that the whales performed two types of dives; ‘regular’ and ‘deep’ dives with Inter Breath Intervals (IBI) of 22.0s (SD=4.7) and 635.6s (SD=405.4) respectively. Blue Whales off southern Sri Lanka spend 75% of their time performing ‘regular’ dives. Accordingly; we estimated that their mean IBI was approximately 173s. These preliminary results obtained using HMM may provide a more accurate correction factor than that obtained from the raw data. This may refine estimates of whale density and abundance for the area

3D terrain mapping and filtering from coarse resolution data cubes extracted from real-aperture 94 GHz radar

Funding: William D. Harcourt was funded by the Engineering and Physical Sciences Research Council (EPSRC; grant number: EP/R513337/1) and the Scottish Alliance for Geoscience, Environment and Society (SAGES).Accurate, high-resolution 3-D mapping of environmental terrain is critical in a range of disciplines. In this study, we develop a new technique, called the PCFilt-94 algorithm, to extract 3-D point clouds from coarse-resolution millimeter-wave radar data cubes and quantify their associated uncertainties. A technique to noncoherently average neighboring waveforms surrounding each AVTIS2 range profile was developed to reduce speckles and was found to reduce point cloud uncertainty by 13% at long range and 20% at short range. Furthermore, a Voronoi-based point cloud outlier removal algorithm was implemented, which iteratively removes outliers in a point cloud until the process converges to the removal of 0 points. Taken together, the new processing methodology produces a stable point cloud, which means that: 1) it is repeatable even when using different point cloud extraction and filtering parameter values during preprocessing and 2) is less sensitive to overfiltering through the point cloud processing workflow. Using an optimal number of ground control points (GCPs) for georeferencing, which was determined to be 3 at close ranges (3 km), point cloud uncertainty was estimated to be approximately 1.5 m at 1.5 km to 3 m at 3 km and followed a Lorentzian distribution. These uncertainties are smaller than those reported for other close-range radar systems used for terrain mapping. The results of this study should be used as a benchmark for future application of millimeter-wave radar systems for 3-D terrain mapping.Peer reviewe

Pairs of Fish Resolve Conflicts over Coordinated Movement by Taking Turns

SummaryWhen individuals stand to gain by interacting with one another, but disagree over their preferred course of collective action, coordination can be hard to achieve [1–4]. In previous work, we found that pairs of stickleback fish prefer to synchronize their trips out of cover to look for food [5], possibly because this reduces perceived predation risk [6]. To create a degree of conflict over group coordination, we trained individual fish to expect food at one of two alternative, exposed locations and paired individuals with different expectations. Compared with isolated individuals, members of a pair showed a significantly increased tendency to alternate between foraging sites, together taking turns to visit first one individual's favored site and then the other individual's. Using a Markov-chain model to infer the individual rules underlying their joint behavior, we found that fish respond to a partner that breaks the pattern of alternation by themselves reverting to less regular behavior. Our results confirm theoretical predictions that conflict over group coordination can be resolved by taking turns [7–10] and show that, in this system, the pattern of alternation is actively monitored and maintained