Trophic history of French sub-alpine lakes over the last ~150 years: phosphorus reconstruction and assessment of taphonomic biases

Like many lakes worldwide, French sub-alpine lakes (lakes Annecy, Bourget and Geneva) have suffered from eutrophication in the mid-20th century. Although restoration measures have been undertaken and resulted in significant reductions in nutrient inputs and concentrations over the last 30 years in all three lakes, the limnological monitoring does not extend back far enough to establish the reference conditions, as defined by the European Water Framework Directive. The over-arching aim of this work was to reconstruct, using a paleolimnological approach, the pre-eutrophication levels and subsequent temporal changes in the lakes trophic status over the last century. The objectives were three-fold: i) to test whether fossil diatoms archived in deep sediment cores adequately reflect past changes in the planktonic diatom communities for these deep sub-alpine lakes based on data from lake Geneva; ii) to investigate changes in the diatom communities over the last 150 years in the three lakes; and iii) to infer the past total phosphorus (TP) concentrations of the lakes from a diatom based transfer function. Annual paleolimnological and limnological diatom countings for lake Geneva were strongly correlated over the last 30 years. Most notable differences essentially resulted from both taphonomic and depositional biases, as evidenced by the underestimation of thin skeleton species such as Asterionella formosa and Diatoma tenuis in the paleolimnological dataset and the presence of many benthic taxa. The fossil diatom records revealed shifts in the communities in the three lakes over time, most of which were changes typically associated with nutrient enrichment. Indeed, in all three lakes, the proportion of Cyclotella spp. was very high before the 1950s, but these species were then replaced by more eutrophic taxa, such as Stephanodiscus spp, by the mid-20th century. From the 1980s, some but not all diatom species typical of re-oligotrophicated conditions (i.e. Cyclotella sp.) re-appeared in all three lakes. Yet, not all changes that occurred in the diatom communities since then may be attributed to decreasing TP. TP concentrations inferred from weighted averaging with classical deshrinking in lake Annecy and lake Geneva and weighted averaging with inverse deshrinking in Lake Bourget were very close to the monitored values. Comparisons of diatom-inferred TP concentrations to other paleo-proxies for trophic status revealed though that the transfer functions were rather insensitive to changes occurring below 10 ?g L-1, which limits the study ability to set accurate TP reference conditions below this threshold. However, current diatom community compositions arestill rather different from the pre-eutrophication ones, suggesting that reference conditions are still not achieved

New chemolysis for urological calcium phosphate calculi – a study in vitro

BACKGROUND: Advances in techniques have left very few indications for open surgical extraction of urinary stones currently. These advances notwithstanding, the search continues for medical approaches to urinary stone management. In this study, we perform an in vitro study analyzing the efficiency and prospect of two new complex solutions in urological calcium phosphate calculi dissolution. METHODS: Eighteen stones composed mainly of calcium phosphates were taken from patients who underwent kidney stone surgery. These stones were large enough (weight range 0.514–0.928 g) to be fragmented and matched equally into six groups. Chemolysis of phosphate stones was done with six different solvents and was repeated 3 times with 6 stones for each solution. At 24, 48 and 72 h, reduction in weight, percentage weight change, and dissolution rate; the dissolution rates at pH 5.0, 7.0 and 8.5 for each solution, using different cations (Na(+), K(+ )or Ca(2+)), according to different dilutions (1:1, 1:2, 1:3, 1:4) of S1 and S2 were simultaneously determined. RESULTS: Calcium phosphate calculi were poorly dissolved by Phys and Art, and they had a low dissolution rate in pH 8.5 EDTA. The most effective solutions were S1, S2 and R, with 72 h mean dissolution rates: 5.75 ± 0.44 mg/hr (S1), 5.2 ± 0.63 mg/hr (S2), 4.55 ± 0.46 mg/hr (R) ([Image: see text] ± s, p < 0.01 R, S1 and S2 vs Phys, Art and EDTA; p < 0.05, S1 vs R, LSD-test). The mean percentage weight loss at 72 h was: 52.1 ± 15.75 % (S1), 44.4 ± 7.37 % (S2) and 40.5 ± 3.67 % (R) ([Image: see text] ± s, p < 0.01 R, S1 and S2 vs Phys, Art and EDTA, LSD-test). Diluted twice, S1 and S2 had even better effectiveness than their initial solution. The additive of Na(+), K(+ )or Ca(2+ )greatly reduced the dissolution rates of S1, S2. CONCLUSION: Our data indicate that test solutions S1 and S2 are effective solvents in the chemolysis of calcium phosphate stones. At twice dilutions, these solutions are even more useful in the treatment of stone disease

Cryogenic Characterization of FBK RGB-HD SiPMs

We report on the cryogenic characterization of Red Green Blue - High Density (RGB-HD) SiPMs developed at Fondazione Bruno Kessler (FBK) as part of the DarkSide program of dark matter searches with liquid argon time projection chambers. A dedicated setup was used to measure the primary dark noise, the correlated noise, and the gain of the SiPMs at varying temperatures. A custom-made data acquisition system and analysis software were used to precisely characterize these parameters. We demonstrate that FBK RGB-HD SiPMs with low quenching resistance (RGB-HD-LR$_q$) can be operated from 40 K to 300 K with gains in the range $10^5$ to $10^6$ and noise rates on the order of a few Hz/mm$^2$

Inclusion de la tablette tactile dans les projets éducatifs individualisés en éducation précoce spécialisée : perceptions, usages et co-construction parents-pédagogues au sein d’un service éducatif itinérant vaudois

La présente recherche avait pour objectif de rendre compte de la place occupée par la tablette tactile en contexte d’éducation précoce spécialisée : sa perception par les parents et les pédagogues, les objectifs pour lesquels elle est utilisée, la collaboration entre parents et pédagogues autour de la création et la mise en application du projet éducatif individualisé incluant la tablette. Les principaux résultats issus de nos entretiens indiquent une ambivalence entre enthousiasme et réticence envers cet outil. De même, les utilisations diffèrent elles aussi grandement d’un sujet et d’un contexte à l’autre, mais n’ont pas toujours une visée éducative. Le dernier constat concerne la difficulté d’échanger à ce sujet entre parents et pédagogues et donc de construire et appliquer le projet éducatif de manière conjointe. Nous soulèverons finalement le besoin de formations, ressenti par les pédagogues lors de l’introduction de cet outil en milieu professionnel

Recurrence of lithiasis after extracorporeal lithotripsy, percutaneous surgery, and open surgery for calculi of the upper urinary tract

The safety and short-term effectiveness of percutaneous nephrolithotomy (PCNL) and extracorporeal shock wave lithotripsy (ESWL) have already been well established. However, long-term follow-up studies are essential to prove that the recurrence rate after PCNL and/or ESWL is equal or even better than that of surgery. We reviewed 57 patients treated with ESWL monotherapy, 45 patients treated by PCNL (or by PCNL combined with ESWL for complete staghorn stones) and 59 patients treated by open surgery who all had at least three years of follow-up. The overall recurrence rate for ESWL was 37% for PCNL and for open surgery 39%. ESWL, PCNL and open surgery all showed a higher rate of recurrence and persistent bacteriuria when associated with residual stones. Therefore every effort should be made to remove residual fragments following stone treatment. We conclude that because of its efficacy and low morbidity ESWL should be the treatment of choice for most of renal calculi. Complete staghorn calculi are best treated with open surgery because the complete elimination of all calculous material and the eradication of infection are achieved at a higher rate than by PCNL and ESWL