integration of colour bathymetry lidar and dgps surveys for assessing fluvial changes after flood events in the tagliamento river italy

The estimation of underwater features of channel bed surfaces without the use of bathymetric sensors results in very high levels of uncertainty. A revised approach enabling an automatic extraction of the wet areas to create more accurate and detailed Digital Terrain Models (DTMs) is here presented. LiDAR-derived elevations of dry surfaces, water depths of wetted areas derived from aerial photos and a predictive depth-colour relationship were adopted. This methodology was applied at two different reaches of a northeastern Italian gravel-bed river (Tagliamento) before and after two flood events occurred in November and December 2010. In-channel dGPS survey points were performed taking different depth levels and different colour scales of the river bed. More than 10,473 control points were acquired, 1107 in 2010 and 9366 in 2011 respectively. A regression model that calculates channel depths using the correct intensity of three colour bands (RGB) was implemented. LiDAR and water depth points were merged and interpolated into DTMs which features an average error, for the wet areas, of ±14 cm. The different number of calibration points obtained for 2010 and 2011 showed that the bathymetric error is also sensitive to the number of acquired calibration points. The morphological evolution calculated through a difference of DTMs shows a prevalence of deposition and erosion areas into the wet areas

Evaluation of the morphological quality index in the Cordevole river (Bl, Italy)

The European Union (EU) Water Framework Directive (WFD, 2000/60/EC), which came into force in Italy under Decree Law no. 152 of 3rd April 2006, has as its objectives the protection and improvement of aquatic ecosystem status, promoting the sustainable use of water resources and mitigating the effects of floods and droughts. According to this Directive, the ecological classification of a watercourse should be considered in addition to physical-chemical and biological aspects of its hydromorphological condition, in order to define the deviation of the present condition from a pre-defined reference state. The Italian National Institute for Environmental Protection and Research has promoted a methodology called IDRAIM for the hydromorphological analysis of streams. This is an integrated approach aimed at implementing both WFD and EU Flood Directives (2007/60/EC). In this paper, we describe the application of the morphological quality index (MQI) protocol, which is part of the IDRAIM, used for evaluating the morphological quality of the Cordevole River, Province of Belluno, northeastern Italy. General settings and segmentation of the water network through the use of semi-automatic GIS techniques were presented. The MQI data derived from the application of 28 indicators in 42 reaches were then analysed. Most (48%) of the analysed reaches have a good quality status; 38% have a moderate quality status and poor morphological conditions (14%) are due to the presence of artificial elements and to the limited connectivity between hill-slopes and the river corridor

Medium- and short-term channel and island evolution in a disturbed gravel bed river (Brenta River, Italy)

The timing and extent of the morphological and island changes that have occurred in the last thirty years in a gravel bed river that has been heavily impacted by human activities were analysed by nine sets of aerial photographs, repeated topographical measurements and morphological- vegetation surveys. Dam operations and gravel mining activities have produced modifications in the natural sediment regime that have generated important morphological responses in the channel. Large areas of the formerly active channel were colonised by riparian forest, both as islands and as marginal woodlands. The cessation of gravel extraction in the late 1990s seems to be causing incipient reversion of this pattern, with evidence of vegetation erosion/channel widening. Alteration of sediment regime has played a major role in the medium- and short-term channel evolution. However, only relevant flood events (recurrence interval >10 years) appear to determine substantial island erosion and, therefore, the proportion of islands versus channel fluctuates depending on flood history. Smaller scale analysis (sub-reach level) was more effective in describing morphological responses and relationships with the sediment dynamics within the 20 km study reach

An update of the sediment fluxes investigation in the Rio Cordon (Italy) after 25 years of monitoring

Quantification of bed-load transport in high-gradient mountain streams is important, but the field data needed to test transport models are scarce and difficult to obtain. In the present study, we describe the experimental station for monitoring water and sediment fluxes built in 1985 on the Rio Cordon, a small step-pool channel in the eastern Italian Alps. The measuring station consists of an inclined frame that separates fine from coarse sediments (D>20 mm), which are continuously measured by a series of ultrasonic sensors fitted above a storage area. The acquired 25-year dataset, which comprises a high-magnitude/ low-recurrence flood event, has allowed a magnitude-frequency analysis of bed-load volumes to be performed. Results from a combined frequency analysis of peak water discharge and total bed-load volumes are presented. In addition, the integration between the sediment transport dataset and the repeated surveys of sediment sources and of channel changes allowed us to assess the geomorphological effectiveness of different flood events. Despite the importance of the experimental station for making these bed-load observations possible, its maintenance costs are not low and these may have an impact on its future existence. At the same time, improving current instrumentation and future installations with novel technology would make the station an ideal location for calibrating surrogate techniques for sediment transport monitoring

analysis of morphological processes in a disturbed gravel bed river piave river integration of lidar data and colour bathymetry

The magnitude of river morphological changes are better analyzed through the use of quantitative approaches, wherein resolution accuracy and uncertainty assessment are treated as crucial key-factors. In this sense, the creation of precise DEMs (Digital Elevation Models) of rivers represents an affordable tool to analyze geomorphic variations and budgets, except for wetted areas, where reliable channel digitalization can normally be obtained only using expensive bathymetric surveys. The proposed work aims at improving channel surface models without having available bathymetric sensors, by deriving dry areas elevations from LiDAR data and water depth of wetted areas from aerial photos through a predictive depth-colour relationship. The methodology was applied to two different sub-reaches of the Piave River, a gravel-bed river which suffered severe flood events in 2010. Erosion and deposition patterns were identified through DEM differencing, showing a predominance of scour processes which can lead to channel instability situations. The bathymetric output was compared to other previously-derived models confirming the accuracy of the in-channel elevation estimates. Finally, a discussion on the role played by longitudinal protections during the studied flood events is proposed, focusing the attention on the incidence of two major bank erosions that removed significant volumes of stable areas

Molecular assessment of acquired resistance to platinum derivates and pharmacological evaluation of new platinum complexes

Les dérivés du platine (i.e. cisplatine et oxaliplatine) représentent une des classes pharmacologiques les plus utilisées en oncologie, notamment dans les cancers colorectaux. Cependant, leur efficacité est limitée par l’émergence de résistances acquises. Nous avons alors étudié in vitro dans différentes lignées cancéreuses coliques humaines (HCT116, LoVo, SW480, HT29) les conséquences à long terme des dérivés du platine lorsqu’ils sont utilisés dans des conditions tenant compte de la sensibilité cellulaire. Ils provoquent des cassures double-brin (objectivées par l’expression de -H2AX), dont le taux dépend du système p53/p21, du complexe MRN et du niveau de stabilité microsatellitaire. Ils induisent aux plus fortes concentrations ( IC50), une cytostase qui s’accompagne de la formation de cellules géantes macrocytaires et endopolyploïdes, dont certaines acquièrent un phénotype sénescent. Dans le même temps, l’activation des mécanismes de réparation des CDB varie en fonction du dérivé du Pt et de la lignée considérée. A plus long terme, des cellules « résistantes » se développent : elles ont une ploïdie normale, et se caractérisent par une plus grande résistance aux dérivés du platine et la présence de novo d’anomalies chromosomiques récurrentes leur conférant un avantage sélectif potentiel en terme de prolifération. Ces mécanismes pourraient contribuer à expliquer en clinique la survenue d’une résistance à une chimiothérapie pourtant initialement efficace. Parallèlement, nous avons évalué in vitro et in vivo de nouveaux complexes de platine obtenus par pharmacomodulation, et associant un noyau intercalant dérivé de la phénanthroline ou de l’acridine. Les résultats in vitro montrent globalement une amélioration significative de la cytotoxicité. Toutefois, un des composés les plus cytotoxiques in vitro, le [(5,6-diméthyl-1,10-phénanthroline) (S,S-diaminocyclohexane)platine(II)], n’exerce pas d’effet antitumoral dans un modèle syngénique de cancer colique chez le rat BD-IX, mais montre une néphrotoxicité marquée. Ces données soulignent l’insuffisance du criblage in vitro et la discordance in vitro/in vivo.Platinum compounds (i.e. cisplatin and oxaliplatin) represent a class of DNA-damaging agents widely used in clinic especially in the treatment of colorectal cancer. However, their effectiveness is restricted because of emergence of acquired resistance. Therefore, long-term effects of platinum compounds, used at conditions reflecting the in vitro cellular sensibility, were assessed in vitro in several human colon cancer cell lines (HCT116, LoVo, SW480, HT29). Their cytotoxicity is related to double-strand break formation (objectived by -H2AX expression), which depends on p53/p21 status, MRN complex and microsatellite stability of the cell line. Furthermore, at the highest concentrations ( IC50), cells stopped their proliferation and exhibited phenotypic alterations resulting from progressive polyploidy and/or senescence. In the same time, DNA repair systems are activated differently according to the platinum derivate and the cell line. At later stages, cells that are more resistant to platinum compounds than their parental counterpart emerged. They have recovered their basal level of ploidy and acquired de novo recurrent chromosomal aberrations. Such mechanisms could contribute to the recurrence of clinical malignancies, even after an effective initial response to chemotherapy. On the other hand, pharmacological evaluation of new platinum compounds with phenanthroline or acridine intercalating ligand was performed in vitro and in vivo. Globally, many compounds exhibited a higher cytotoxic effect than cisplatin or oxaliplatin in all cell lines studied. Unfortunately, in vivo investigations of one of the most cytotoxic compounds ([(5,6-dimethyl-1,10-phenanthroline) (S,S-diaminocyclohexane)platinum(II)]) did not exhibit antitumor effect in BD-IX rats bearing peritoneal carcinomatosis, whatever the route of administration used (systemic or local), but it displayed nephrotoxicity. These results query the in vitro/in vivo correlation and reconsider the place of the in vivo screening

Conséquenses chromosomiques et moléculaires d'un traitement par les dérivés du platine dans des lignées cancéreuses coliques

DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

The role of arginase in aging: A systematic review

International audienc

Human-based evidence for the therapeutic potential of arginase inhibitors in cardiovascular diseases

International audienc

Etude moléculaire de mécanismes de résistance acquise aux dérivés du platine et évaluation pharmacologique de nouveaux dérivés du platine à activité antitumorale

Les dérivés du platine (i.e. cisplatine et oxaliplatine) représentent une des classes pharmacologiques les plus utilisées en oncologie, notamment dans les cancers colorectaux. Cependant, leur efficacité est limitée par l émergence de résistances acquises. Nous avons alors étudié in vitro dans différentes lignées cancéreuses coliques humaines (HCT116, LoVo, SW480, HT29) les conséquences à long terme des dérivés du platine lorsqu ils sont utilisés dans des conditions tenant compte de la sensibilité cellulaire. Ils provoquent des cassures double-brin (objectivées par l expression de -H2AX), dont le taux dépend du système p53/p21, du complexe MRN et du niveau de stabilité microsatellitaire. Ils induisent aux plus fortes concentrations ( IC50), une cytostase qui s accompagne de la formation de cellules géantes macrocytaires et endopolyploïdes, dont certaines acquièrent un phénotype sénescent. Dans le même temps, l activation des mécanismes de réparation des CDB varie en fonction du dérivé du Pt et de la lignée considérée. A plus long terme, des cellules résistantes se développent : elles ont une ploïdie normale, et se caractérisent par une plus grande résistance aux dérivés du platine et la présence de novo d anomalies chromosomiques récurrentes leur conférant un avantage sélectif potentiel en terme de prolifération. Ces mécanismes pourraient contribuer à expliquer en clinique la survenue d une résistance à une chimiothérapie pourtant initialement efficace. Parallèlement, nous avons évalué in vitro et in vivo de nouveaux complexes de platine obtenus par pharmacomodulation, et associant un noyau intercalant dérivé de la phénanthroline ou de l acridine. Les résultats in vitro montrent globalement une amélioration significative de la cytotoxicité. Toutefois, un des composés les plus cytotoxiques in vitro, le [(5,6-diméthyl-1,10-phénanthroline) (S,S-diaminocyclohexane)platine(II)], n exerce pas d effet antitumoral dans un modèle syngénique de cancer colique chez le rat BD-IX, mais montre une néphrotoxicité marquée. Ces données soulignent l insuffisance du criblage in vitro et la discordance in vitro/in vivo.Platinum compounds (i.e. cisplatin and oxaliplatin) represent a class of DNA-damaging agents widely used in clinic especially in the treatment of colorectal cancer. However, their effectiveness is restricted because of emergence of acquired resistance. Therefore, long-term effects of platinum compounds, used at conditions reflecting the in vitro cellular sensibility, were assessed in vitro in several human colon cancer cell lines (HCT116, LoVo, SW480, HT29). Their cytotoxicity is related to double-strand break formation (objectived by -H2AX expression), which depends on p53/p21 status, MRN complex and microsatellite stability of the cell line. Furthermore, at the highest concentrations ( IC50), cells stopped their proliferation and exhibited phenotypic alterations resulting from progressive polyploidy and/or senescence. In the same time, DNA repair systems are activated differently according to the platinum derivate and the cell line. At later stages, cells that are more resistant to platinum compounds than their parental counterpart emerged. They have recovered their basal level of ploidy and acquired de novo recurrent chromosomal aberrations. Such mechanisms could contribute to the recurrence of clinical malignancies, even after an effective initial response to chemotherapy. On the other hand, pharmacological evaluation of new platinum compounds with phenanthroline or acridine intercalating ligand was performed in vitro and in vivo. Globally, many compounds exhibited a higher cytotoxic effect than cisplatin or oxaliplatin in all cell lines studied. Unfortunately, in vivo investigations of one of the most cytotoxic compounds ([(5,6-dimethyl-1,10-phenanthroline) (S,S-diaminocyclohexane)platinum(II)]) did not exhibit antitumor effect in BD-IX rats bearing peritoneal carcinomatosis, whatever the route of administration used (systemic or local), but it displayed nephrotoxicity. These results query the in vitro/in vivo correlation and reconsider the place of the in vivo screening.DIJON-BU Doc.électronique (212319901) / SudocSudocFranceF