Les populations néoteniques de Triturus helveticus des causses et du Bas-Languedoc I. Répartition et caractéristiques

Neoteny is common in some populations of Palmate newts Triturus helveticus of Southern France. Population samples have been collected from 117 pools, at three different seasons of the year. Percentages of neotenic individuals have been calculated for 29 of these pools where neotenic newts were found. Neoteny is not evenly distributed over the whole study area. It is more prevalent in the S.E. part of the Causse du Larzac and in the Causse de Blandas, than in the coastal plains of Languedoc. On the “ causses ” (arid limestone tablelands), neoteny only occurs among palmate newts, no neotenic individual having ever been found among the sympatric Triturus marmoratus population. Morphological differences between neotenic and normal popu lations of Triturus helveticus are described. None of them is consistent enough to allow sub-specific status to be given to the neotenic population. Breeding takes place later in the season among the Larzac population and the duration of the aquatic phase of the yearly cycle is also longer in the plateau population than among the newts of the coastal plains. All these differences, morphological as well as biological, disappear when the newts are kept in labo ratory conditions. Metamorphosis occurs normally when the progeny of both newt populations are bred in the laboratory. However mortality is much higher among the progeny of neotenic females, during their first three months of life

Les populations néoténiques de Triturus helveticus Raz. des Causses et du Bas-Languedoc. II. Ecologie

The physical, chemical, and biotic characteristics of the ponds where neotenic populations of Palmate newts are found in Sou thern France are described. The frequency of neoteny is high in permanent ponds, at an altitude ranging from 400 to 700 m, on arid limestone plateaux with a yearly rainfall of 1500-2000 mm. In such areas there are large seasonal variations of water temperature, ranging from + 1 to + 28 °C, water remaining cold (below + 15°C) for 8 to 10 months during the year. The saline content of water is low, as shown by conductivity figures (less than 200 pmhos/cm/cm2) . No iodine deficiency was ever found in the ponds of the study area. A correlation has been found between the frequency of neoteny and the water concentration in Ca, Mg and particularly K (which may account for 35-40 % of the cations) . The aridity of the area surrounding the pools can also contri bute to the selection of neotenic individuals, paedogenesis being of obvious adaptive value in such an environment

Use of a trabecular metal implant in ankle arthrodesis after failed total ankle replacement: A short-term follow-up of 13 patients

Patients and methods 13 patients with a migrated or loose total ankle implant underwent arthrodesis with the use of a retrograde intramedullary nail through a trabecular metal Tibial Cone. The mean follow-up time was 1.4 (0.6-3.4) years. Results At the last examination, 7 patients were pain-free, while 5 had some residual pain but were satisfied with the procedure. 1 patient was dissatisfied and experienced pain and swelling when walking. The implant-bone interfaces showed no radiographic zones or gaps in any patient, indicating union. Interpretation The method is a new way of simplifying and overcoming some of the problems of performing arthrodesis after failed total ankle replacement

Predicting the prices of cards in the game Magic with machine learning

V tem diplomskem delu smo preučevali trende gibanja cen pri kartah igre Magic: The Gathering in pri tem uporabili najbolj primerne metode strojnega ućenja. Cilj je bil izdelati napovedni model za cene kart. Naša naloga je bila identiciranje pomembnih virov, pridobivanje potrebnih podatkov, njihova pretvorba v računalniku razumljivo obliko ter izbira primernega algoritma. Model, ki smo ga ustvarili, se je izkazal za zanesljivega s 61% točnostjo napovedi gibanja cene pri zelo redkih kartah, medtem ko smo pri redkih kartah dosegli le 52% točnost, kar ni preseglo niti privzete točnosti. Pri nalogi smo uporabili metodo podpornih vektorjev ter si pomagali z orodjem Weka. S podatki, ki smo jih pridobili, smo naredili še nekaj poizkusov in tako poiskali nekaj novih odvisnosti med podatki, ki jih prej nismo poznali.This thesis is a study of Magic: The Gathering card price fluctuations using the most appropriate machine learning methods. The goal was to construct a predictive model for card prices. This required us to identify crucial attributes, gather necessary data, convert it to a machine-readable format and select a suitable learning algorithm for the task. The resulting model was effective, attaining a 61 % price trend accuracy with mythic rare cards, while it was less successful with rare cards with only 52% accuracy, which failed to beat default accuracy. Support vector machines algorithms and the machine learning toolbox Weka were used to achieve these results, which were applied in further experiments that led to the discovery of previously unknown data dependencies

Les populations néoténiques de Triturus helveticus des Causses et du Bas-Languedoc. I. Répartition et caractéristiques

Neoteny is common in some populations of Palmate newts Triturus helveticus of Southern France. Population samples have been collected from 117 pools, at three different seasons of the year. Percentages of neotenic individuals have been calculated for 29 of these pools where neotenic newts were found. Neoteny is not evenly distributed over the whole study area. It is more prevalent in the S.E. part of the Causse du Larzac and in the Causse de Blandas, than in the coastal plains of Languedoc. On the “causses” (arid limestone tablelands), neoteny only occurs among palmate newts, no neotenic individual having ever been found among the sympatric Triturus marmoratus population. Morphological differences between neotenic and normal populations of Triturus helveticus are described. None of them is consistent enough to allow sub-specific status to be given to the neotenic population. Breeding takes place later in the season among the Larzac population and the duration of the aquatic phase of the yearly cycle is also longer in the plateau population than among the newts of the coastal plains. All these differences, morphological as well as biological, disappear when the newts are kept in laboratory conditions. Metamorphosis occurs normally when the progeny of both newt populations are bred in the laboratory. However mortality is much higher among the progeny of neotenic females, during their first three months of life.Gabrion J., Sentein P., Gabrion C. Les populations néoténiques de Triturus helveticus des Causses et du Bas-Languedoc. I. Répartition et caractéristiques. In: La Terre et La Vie, Revue d'Histoire naturelle, tome 31, n°3, 1977. pp. 489-506

Les populations néoténiques de Triturus helveticus Raz. des Causses et du Bas-Languedoc. II. Écologie

The physical, chemical, and biotic characteristics of the ponds where neotenic populations of Palmate newts are found in Southern France are described. The frequency of neoteny is high in permanent ponds, at an altitude ranging from 400 to 700 m, on arid limestone plateaux with a yearly rainfall of 1500-2000 mm. In such areas there are large seasonal variations of water temperature, ranging from + 1 to + 28°C, water remaining cold (below + 15°C) for 8 to 10 months during the year. The saline content of water is low, as shown by conductivity figures (less than 200 μmhos/cm/cm²). No iodine deficiency was ever found in the ponds of the study area. A correlation has been found between the frequency of neoteny and the water concentration in Ca, Mg and particularly K (which may account for 35-40 % of the cations). The aridity of the area surrounding the pools can also contri¬ bute to the selection of neotenic individuals, paedogenesis being of obvious adaptive value in such an environment.Gabrion J., Sentein P., Gabrion C. Les populations néoténiques de Triturus helveticus Raz. des Causses et du Bas-Languedoc. II. Écologie. In: La Terre et La Vie, Revue d'Histoire naturelle, tome 32, n°4, 1978. pp. 577-610

Numerical response of a helminth community in the course of a multi-annual abundance cycle of the Water Vole (Arvicola terrestris)

International audienceThe impact of parasitism on population dynamics is determined in part by the numerical responses of parasites during population fluctuations of their hosts. Vole populations fluctuate in multi-annual cycles allowing such responses to be studied over successive phases of population growth, abundance and decline. We investigate how a helminth community (5 nematode and 7 cestode species) evolved over a full 6-year Water Vole (Arvicola terrestris) population cycle. Brillouin and individual parasite species richness (IPSR) indices were used to measure the numerical response of the parasite community. We report a correlation between levels of parasite intensity and vole population cycle phases. Both indices were consistently higher during pre-decline and decline phases for male and female voles alike. The numerical response of the parasite community suggests that populations may be regulated by parasitism and that studies of this mechanism should allow both for the cyclic or non-cyclic character of the host populations and for the response of the broadest possible set of the local parasite community

One-year prospective comparative study of three large-diameter metal-on-metal total hip prostheses: Serum metal ion levels and clinical outcomes

SummaryIntroductionThe good clinical outcomes and low wear obtained with 28-mm metal-on-metal implants for total hip replacement prompted the development of large-diameter heads that more closely replicated the normal hip anatomy, with the goal of improving prosthesis stability. However, the blood release of metal ions due to wear at the bearing surfaces and the high rate of groin pain seen with large-diameter implants are causing concern. To determine whether these events are related to the geometry and metal composition of the prosthesis components, we conducted a prospective study of clinical outcomes and serum chromium and cobalt levels 1 year after implantation of three different acetabular cups.HypothesisSerum levels of metal ions are comparable with different types of large-diameter metal-on-metal total hip prostheses.Patients and methodsWe compared 24 Durom™ cups (D), 23 M2a Magnum™ cups (M2a), and 20 Conserve Total™ (C) cups regarding serum chromium and cobalt levels, Postel-Merle d’Aubigné (PMA) scores and Oxford Hip Scores (OHS), as well as radiographic cup orientation and position at 1-year follow-up. Mean age was 66 years (45–85 years), mean body mass index was 28 Kg/m2 (18–45), patients were almost equally divided between males and females, and the reason for hip replacement was primary hip osteoarthritis in 65 patients and avascular necrosis in two. Metal ions were assayed in serum from blood drawn through non-metallic catheters, using mass spectrometry.ResultsDislocation occurred in two patients (one D and one M2a) and revision to change the bearing couple was required in two patients in the D group. Serum cobalt levels in the C group were significantly higher (P=0. 0003) than in the two other groups (7.5μg/L versus 2. 7μg/L with D and 2. 2μg/L with M2a). Clinical outcomes were better in the M2a group (PMA, 17.7 [16–18]; and OHS, 15.2 [12–30]; P<0.05). The PMA score and OHS were 17.5 (16–18) and 18.2 (12–42), respectively, with D; and 16.75 (10–18) and 22. 2 (12–42), respectively, with C cups. When all three cup models were pooled, serum ion levels were higher in patients with pain than without pain (chromium, 7.1μg/L versus 2.1μg/L [P=0.002], and cobalt, 8μg/L versus 2.6μg/L [P=0.0004]).DiscussionSerum chrome and cobalt levels increased after metal-on-metal total hip replacement, and the increase was greater with large-diameter implants than previously reported with 28-mm implants. Persistent pain was significantly associated with higher metal ion levels, with a probable cobalt cut-off of about 8μg/L. Differences in modular head-neck concepts may explain the observed variations.Level of evidenceIII, prospective comparative study