Evaluation of remaining dentin thickness around the prepared root canals and its influence on the temperature changes on the external root surfaces during different heated gutta-percha obturation techniques.

CONTEXT: Temperature rise on external root surface has a deleterious effect on the periodontium. AIMS: To compare and evaluate the temperature changes on the external root surfaces using three different heated gutta-percha obturation techniques and also to evaluate the effect of remaining dentin thickness (RDT) on the temperature rise during obturation. SETTINGS AND DESIGN: In vitro study with a customized temperature measurement setup. MATERIALS AND METHODS: Thirty decoronated human maxillary central incisors were cleaned and shaped using standardized method. RDT was measured using cone beam computed tomography. They were divided into three groups of 10 samples each. Group 1 was obturated by traditional warm vertical compaction, Group 2 using solid core obturation, and Group 3 by warm vertical compaction technique using GP heater in vibration mode. AH Plus sealer was used as cement sealer. During obturation, the temperature rise was measured using K-type thermocouples in the coronal, middle, and apical thirds. The highest temperature rise during the procedure was recorded. STATISTICAL ANALYSIS USED: Data were analyzed by one-way analysis of variance and post hoc Tukey's test. RESULTS: Traditional warm vertical compaction had the highest temperature change followed by warm vertical compaction using GP heater in vibration mode and solid core obturation. CONCLUSION: There was a temperature rise on external root surfaces in the three techniques evaluated. Solid core obturation technique showed the least temperature change. There was no significance in the effect of RDT on temperature rise during obturation.

Mapping potential, existing and efficient wetlands using free remote sensing data.

Although wetlands remain threatened by human pressures and climate change, monitoring and managing them are challenging due to their high spatial and temporal dynamics within a fine-grained pattern. New satellite time-series at high temporal and spatial resolutions provide a promising opportunity to map and monitor wetlands. The objective of this study was to develop an operational method for managing valley bottom wetlands based on available free remote sensing data. The Potential, Existing, Efficient Wetlands (PEEW) approach was adapted to remote sensing data to delineate three wetland components: (1) potential wetlands, mapped from a digital terrain model derived from LiDAR data; (2) existing wetlands, delineated from land cover maps derived from Sentinel-1/2 time-series; and (3) efficient wetlands, identified from functional indicators (i.e. annual primary production, vegetation phenology, seasonality of carbon flux) derived from MODIS annual time-series. Soil and vegetation samples were collected in the field to calibrate and validate classification of remote sensing data. The method was applied to a 113 000 ha watershed in northwestern France. Results show that potential wetlands were successfully delineated (82% overall accuracy) and covered 21% of the watershed area, while 44% of existing wetlands had been lost. Small wetlands along headwater channels, which are considered as ordinary, cover 56% of wetland area in the watershed. Efficient wetlands were identified as contiguous pixels with a similar temporal functional trajectory. This method, based on free remote sensing data, provides a new perspective for wetland management. The method can identify sites where restoration measures should be prioritized and enables better understanding and monitoring of the influence of management practices and climate on wetland functions.

Ditch network sustains functional connectivity and influences patterns of gene flow in an intensive agricultural landscape.

In intensive agricultural landscapes, plant species previously relying on semi-natural habitats may persist as metapopulations within landscape linear elements. Maintenance of populations' connectivity through pollen and seed dispersal is a key factor in species persistence in the face of substantial habitat loss. The goals of this study were to investigate the potential corridor role of ditches and to identify the landscape components that significantly impact patterns of gene flow among remnant populations. Using microsatellite loci, we explored the spatial genetic structure of two hydrochorous wetland plants exhibiting contrasting local abundance and different habitat requirements: the rare and regionally protected Oenanthe aquatica and the more commonly distributed Lycopus europaeus, in an 83 km(2) agricultural lowland located in northern France. Both species exhibited a significant spatial genetic structure, along with substantial levels of genetic differentiation, especially for L. europaeus, which also expressed high levels of inbreeding. Isolation-by-distance analysis revealed enhanced gene flow along ditches, indicating their key role in effective seed and pollen dispersal. Our data also suggested that the configuration of the ditch network and the landscape elements significantly affected population genetic structure, with (i) species-specific scale effects on the genetic neighborhood and (ii) detrimental impact of human ditch management on genetic diversity, especially for O. aquatica. Altogether, these findings highlighted the key role of ditches in the maintenance of plant biodiversity in intensive agricultural landscapes with few remnant wetland habitats.