186,345 research outputs found
Feeding competition between two goby species, Pomatoschistus lozanoi (de Buen) and P. minutus (Pallas), in a macrotidal satmarsh.
No full textTwo transient goby species (Pomatoschistus minutus and P. lozanoi) occurred in saltmarshes of the macrotidal Mont Saint Michel bay. They colonised the tidal creeks during each spring tide all along the study conducted in 1997. P. minutus swallowed a least 4% of its body weight. Its diet was dominated by the most abundant resident amphipod of the saltmarshes, Orchestia gammarellus. P. lozanoi ingested less food during their stay in the creek (2.4% of its body weight). O. gammarallus also occurred in its diet, but mysids were the main food items both during flood and ebb. In addition to this trophic segregation, a temporal segregation was observed. In fact, P. minutus stayed longer than P. lozanoi in the saltmarsh ; it colonised creeks first and returned to coastal waters the last. These two predatory and sympatric species had a different trophic behaviour that limited interspecific competition both from the trophic and temporal point of view
Fontaine-Laffaille modules and strongly divisible modules
No full textIn this note, we study the relation between Fontaine-Laffaille modules and
strongly divisible modules, without assuming the main theorem of
Fontaine-Laffaille (but we need to assume the main results concerning strongly
divisible modules). This in particular gives a new proof for the main theorem
of Fontaine-Laffaille (for ).Comment: Final version. Updated numbering system to match with published
versio
Fontaine-Laffaille Theory over Power Series Rings
No full textLet be a perfect field of characteristic . We extend the equivalence of categories between Fontaine-Laffaille modules and lattices inside crystalline representations with Hodge-Tate weights at most of Fontaine and Laffaille to the situation where the base ring is the power series ring over the Witt vectors and where the base ring is a -adically complete ring that is étale over the Tate Algebra .41 page
The Geometry of Fontaine--Laffaille modules
No full textFontaine--Laffaille modules are linear algebra objects that correspond to certain mod-p Galois representations. These Fontaine--Laffaille modules together with fixed bases compatible with the filtration are parameterized by the variety U\GL_n, where U is the subgroup of GL_n consisting of the upper-triangular unipotent matrices. In this short lecture series, we introduce the geometry of U\GL_n, and interpret some representation theoretic properties in terms of geometric languages
Prismatic -Gauges and Fontaine--Laffaille modules
No full textLet be a perfect field of characteristic and its ring of Witt
vectors. We construct an equivalence of categories between the full subcategory
of the derived category of quasi-coherent sheaves on the syntomification of
spanned by objects whose Hodge-Tate weights are between and an
appropriate derived category of Fontaine-Laffaille modules.Comment: 39 page
Assessing the freshwater distribution of yellow eel
No full textIn the global context of the decline in wild species, modeling the distribution of populations is a crucial aspect of ecological management. This can be a major challenge, especially for species, such as the European eel, that have complex life cycles, exhibit cryptic behavior, or migrate over long distances. A review of the literature suggests that eel size data could be used to assess and analyze freshwater distribution of eel. We argue that analyses based on small yellow eels (≤ 300 mm) along the longitudinal course of rivers could provide a valuable tool for population monitoring. We propose a standardized catchment recruitment index and a colonization index based on the probability of occurrence (presence/absence data) using logistic models for different size classes. The model developed here provides a convenient guide for assessing yellow eel stages in freshwater areas, and should have concrete applications for management of the species
Relative Fontaine-Laffaille Theory over Power Series Rings
No full textLet k be a perfect field of characteristic p > 2. We extend the equivalence of categories between Fontaine-Laffaille modules and Z_p lattices inside crystalline representations with Hodge-Tate weights at most p-2 of Fontaine to the situation where the base ring is the power series ring in d variables over the ring of Witt vectors of k. </p
The yellow European eel (Anguilla anguilla L.) may adopt a sedentary lifestyle in inland freshwaters
No full textWe analysed the movements of the growing yellow phase using a long-term mark–recapture programme on European eels in a small catchment (the Frémur, France). The results showed that of the yellow eels (>200 mm) recaptured, more than 90% were recaptured at the original marking site over a long period before the silvering metamorphosis and downstream migration. We conclude that yellow European eels >200 mm may adopt a sedentary lifestyle in freshwater area, especially in small catchment
Strategy of recreational anglers and estimated eel (Anguilla anguilla) catches in a large European catchment basin, the Loire (France)
No full textThe European Council Regulation (18 September 2007) for the recovery of eel stocks required European states to report on eel stocks and anthropic mortalities. The data sources for France reveal gaps in our knowledge about angling in the public domain, and catches from privately-owned rivers. We tested a simple method, using a survey, for estimating the strategy employed and the catches landed by the 350 000 anglers fishing in the Loire catchment area. The first findings show that the answers of the fishermen varied between 1 and 2% in the departments with the most eels, and between 0.1 and 0.2% in the departments located further upstream. The interest in eel fishing, the average weight of the eels caught by the fishermen, and the total catch all decreased from downstream to upstream. Finally, we estimated the annual average weight of eel caught by anglers, which ranged from 0.8 to 5.3 kg per year depending on the department and the local interest in eel fishing. This preliminary study shows that it is possible to estimate the different fishing strategies used and the quantities caught by means of a survey
Fontaine--Laffaille modules and their mod-p local-global compatibility
No full textLet K be a finite extension of Qp. It is believed that one can attach a smooth Fp-representation of GLn(K) (or a packet of such representations) to a continuous Galois representation of Gal(K/Qp) with coefficients in GLn(Fp) in a natural way, that is called mod p Langlands program for GLn(K). This is known only for GL2(Qp): one of the main difficulties is that there is no classification of such smooth representations of GLn(K) unless K = Qp and n = 2. However, for a given continuous Galois representation R of Gal(K/Qp) with coefficients in GLn(Fp), one can define a smooth Fp-representation P of GLn(K) by a space of mod p automorphic forms on a compact unitary group, which is believed to be a candidate on the automorphic side corresponding to R for mod p Langlands correspondence in the spirit of Emerton. The structure of P is very mysterious as a representation of GLn(K), but it is conjectured that P determines R, which is called mod-p local-global compatibility. In this talk, we discuss a way to prove this conjecture in the case that R is Fontaine--Laffaille. More precisely, we prove that the tamely ramified part of R is determined by the Serre weights attached to R, and the wildly ramied part of R is obtained in terms of refined Hecke actions on P. This is based on a joint work with Daniel Le, Bao Le Hung, Stefano Morra, and Zicheng Qian
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