Saving the European eel : how morphological research can help in effective conservation management

The European eel (Anguilla anguilla) is a critically endangered species, whose recruitment stocks have declined to nearly 1% compared to the late 70s. An amalgam of factors is responsible for this, among them migration barriers, pollution, habitat loss, parasite infection, and overfishing. A lot of recent studies focus on aspects that can increase the mature silver eel escapement rate, such as identifying migration barriers and developing passageways or addressing the impact of pollution on the eel’s health. However, little attention is given to the eel’s morphology in function of management measures. Worryingly, less than 50% of the currently installed management plans reach their goals, strongly indicating that more information is needed about the eel’s ecology and behavior. Functional morphological studies provide insights on how species perform behaviors crucial for survival, such as feeding and locomotion, but also in how environmental changes can affect or limit such behaviors. Consequently, functional morphology represents an important biotic component that should be taken into account when making conservation decisions. Hence, here, we provide an overview of studies on the eel’s morphology that do not only demonstrate its relation with ecology and behavior, but also provide information for developing and installing proper and more specific management measures

Raising rivals’ costs strategy: test on two LAFS in Europe

Some Localised Agro-Food Systems (LAFS) are traditionally qualified as success stories (Comté PDO in France, Gruyere PDO in Switzerland, Parmigiano Reggiano PDO in Italy), whilst other PDOs (as for example the Cantal PDO from France) pay the same price for the milk as standard milk. The price difference may reach between 10 and 25% over a long period. To explain this difference, we assume that the agents who make up the LAFS developed a collective action to protect their localized cheese production system against unfair competition and to promote their product outside its region of origin. The aim of this communication is to shed light on levers which the agents activate to assure their uniqueness is irrevocable, and uphold the benefits of their LAFS. We propose to discuss the idea that the search for market power based on the strategy of raising rivals’ costs may be used even outside a situation of vertical integration or a situation in which pressure is applied to suppliers to challenge competitors. We assume that some companies within the LAFS have sufficient control on the rules governing the organization of the traditional system to benefit from it. They also succeed in protecting a kind of relationship between business companies. The Raising Rivals’ Costs theory helps to analyze the economic consequences of the legal set-up implementation and of its control by some companies. Indeed, we show that the collective control of the rules which are set up in the PDO legal framework explain the difficulties met by rivals to stand out through an alternative and independent production system based on the costs leadership strategy. The collective set up of institutions and rules help the agents to achieve a collective competitive advantage in which every agent benefits individually. This is the strategy developed in Europe and particularly for two PDO Localised Agro-cheese Systems: Comté PDO for France and Gruyère PDO for Switzerland.PDO, localised agro-food system, Raising rivals’ costs, regulation, Agribusiness, Agricultural and Food Policy, Community/Rural/Urban Development, Food Consumption/Nutrition/Food Safety, Labor and Human Capital,

RAISING RIVALS’ COSTS STRATEGYAND LOCALISED AGRO-FOOD SYSTEMS IN EUROPE

For some Localised Agro-Food Systems (LAFS), for ex. Comté in France, Gruyère in Switzerland, the cheese and milk prices are above average whilst others as for example the Cantal from France are similar or even below average. The objective of this paper is to shed light on levers which the agents activate to assure their uniqueness is irrevocable, and uphold the benefits of their LAFS. Raising Rivals' Costs Theory gives interesting point of view about the behaviour of firms which could make use of the collective rules to raise the costs of their competitors in the particular case of LAFS oriented to the production of traditional cheeses. This will be explored through two cases studies. In the first case (territorial collective governance mode of the local supply chain), the conditions are met to conclude that the raising costs strategy corresponds to requirements which are based to a corresponding quality which meets consumers’ expectations and willingness to pay. In the second case (sectoral governance mode), few firms have taken control on the supply chain and have imposed with the time a model based on costs leadership. As conclusion, a case-by-case in-depth approach is necessary to assess whether strategy to raise costs of the rivals damages consumers welfare in the case of PDO supply chains.PDO, localised agro-food system, Raising Rivals’ Costs, governance of LAFS, Agribusiness,

Numerical models for the circumstellar medium around Betelgeuse

The nearby red supergiant (RSG) Betelgeuse has a complex circumstellar medium out to at least 0.5 parsecs from its surface, shaped by its mass-loss history within the past 0.1 Myr, its environment, and its motion through the interstellar medium (ISM). In principle its mass-loss history can be constrained by comparing hydrodynamic models with observations. Observations and numerical simulations indicate that Betelgeuse has a very young bow shock, hence the star may have only recently become a RSG. To test this possibility we calculated a stellar evolution model for a single star with properties consistent with Betelgeuse. We incorporated the resulting evolving stellar wind into 2D hydrodynamic simulations to model a runaway blue supergiant (BSG) undergoing the transition to a RSG near the end of its life. The collapsing BSG wind bubble induces a bow shock-shaped inner shell which at least superficially resembles Betelgeuse's bow shock, and has a similar mass. Surrounding this is the larger-scale retreating bow shock generated by the now defunct BSG wind's interaction with the ISM. We investigate whether this outer shell could explain the bar feature located (at least in projection) just in front of Betelgeuse's bow shock.Comment: 5 pages, 3 figures; to appear in proceedings of the Betelgeuse 2012 Workshop, Paris, Nov. 201

Reconstructing the projected gravitational potential of Abell 1689 from X-ray measurements

Context. Galaxy clusters can be used as cosmological probes, but to this end, they need to be thoroughly understood. Combining all cluster observables in a consistent way will help us to understand their global properties and their internal structure. Aims. We provide proof of the concept that the projected gravitational potential of galaxy clusters can directly be reconstructed from X-ray observations. We also show that this joint analysis can be used to locally test the validity of the equilibrium assumptions in galaxy clusters. Methods. We used a newly developed reconstruction method, based on Richardson-Lucy deprojection, that allows reconstructing projected gravitational potentials of galaxy clusters directly from X-ray observations. We applied this algorithm to the well-studied cluster Abell 1689 and compared the gravitational potential reconstructed from X-ray observables to the potential obtained from gravitational lensing measurements. [...] Results. Assuming spherical symmetry and hydrostatic equilibrium, the potentials recovered from gravitational lensing and from X-ray emission agree very well beyond 500 kpc. Owing to the fact that the Richardson-Lucy deprojection algorithm allows deprojecting each line of sight independently, this result may indicate that non-gravitational effects and/or asphericity are strong in the central regions of the clusters. Conclusions. We demonstrate the robustness of the potential reconstruction method based on the Richardson-Lucy deprojection algorithm and show that gravitational lensing and X-ray emission lead to consistent gravitational potentials. Our results illustrate the power of combining galaxy-cluster observables in a single, non-parametric, joint reconstruction of consistent cluster potentials that can be used to locally constrain the physical state of the gas.Comment: 8 pages, 4 figures. Accepted in A&

Diet-induced phenotypic plasticity in European eel (Anguilla anguilla)

Two phenotypes are present within the European eel population: broad-heads and narrow-heads. The expression of these phenotypes has been linked to several factors, such as diet and differential growth. The exact factors causing this dimorphism, however, are still unknown. In this study, we performed a feeding experiment on glass eels from the moment they start to feed. Eels were either fed a hard diet, which required biting and spinning behavior, or a soft diet, which required suction feeding. We found that the hard feeders develop a broader head and a larger adductor mandibulae region than eels that were fed a soft diet, implying that the hard feeders are capable of larger bite forces. Next to this, soft feeders develop a sharper and narrower head, which could reduce hydrodynamic drag, allowing more rapid strikes towards their prey. Both phenotypes were found in a control group, which were given a combination of both diets. These phenotypes were, however, not as extreme as the hard or the soft feeding group, indicating that some specimens are more likely to consume hard prey and others soft prey, but that they do not selectively eat one of both diets. In conclusion, we found that diet is a major factor influencing head shape in European eel and this ability to specialize in feeding on hard or soft prey could decrease intra-specific competition in European eel populations

High signal-to-noise spectral characterization of the planetary-mass object HD 106906 b

We spectroscopically characterize the atmosphere of HD 106906b, a young low-mass companion near the deuterium burning limit. The wide separation from its host star of 7.1" makes it an ideal candidate for high S/N and high-resolution spectroscopy. We aim to derive new constraints on the spectral type, effective temperature, and luminosity of HD106906b and also to provide a high S/N template spectrum for future characterization of extrasolar planets. We obtained 1.1-2.5 $\mu$m integral field spectroscopy with the VLT/SINFONI instrument with a spectral resolution of R~2000-4000. New estimates of the parameters of HD 106906b are derived by analyzing spectral features, comparing the extracted spectra to spectral catalogs of other low-mass objects, and fitting with theoretical isochrones. We identify several spectral absorption lines that are consistent with a low mass for HD 106906b. We derive a new spectral type of L1.5$\pm$1.0, one subclass earlier than previous estimates. Through comparison with other young low-mass objects, this translates to a luminosity of log($L/L_\odot$)=$-3.65\pm0.08$ and an effective temperature of Teff=$1820\pm240$ K. Our new mass estimates range between $M=11.9^{+1.7}_{-0.8} M_{\rm Jup}$ (hot start) and $M=14.0^{+0.2}_{-0.5} M_{\rm Jup}$ (cold start). These limits take into account a possibly finite formation time, i.e., HD 106906b is allowed to be 0--3 Myr younger than its host star. We exclude accretion onto HD 106906b at rates $\dot{M}>4.8\times10^{-10} M_{\rm Jup}$yr$^{-1}$ based on the fact that we observe no hydrogen (Paschen-$\beta$, Brackett-$\gamma$) emission. This is indicative of little or no circumplanetary gas. With our new observations, HD 106906b is the planetary-mass object with one of the highest S/N spectra yet. We make the spectrum available for future comparison with data from existing and next-generation (e.g., ELT and JWST) spectrographs.Comment: 11 pages, 5 figures. Accepted for publication in Astronomy & Astrophysics. Fully reduced spectra will be made available for download on CD