Spatiotemporal data of algal blooms phenology

The spatio-temporal data contain annual phytoplankton bloom phenology from 2000 to 2016 on 580 lakes located in the province of Quebec, Canada, between 44 and 50°N and 67 and 80°W. The data include height phenological variables related to phytoplankton blooms, and 17 physiographical, morphological, and climatic descriptors of the lake and the watershed. For each studied year, phenological variables were established as follows: (1) the frequency (the number of days when Chl-a concentrations remained above the threshold), (2) the intensity (the maximum concentration of Chl-a detected during a bloom), (3) the relative area (the maximum area occupied by a bloom normalized by the lake area), (4) the onset date and (5) the end date (respectively, the first and last day of the year when a bloom was detected), and (6) the duration (the number of days between the onset date and the end date). Remote sensing determination of the end date and duration of blooms is challenging because the studied region is frequently covered by clouds during the fall, significantly reducing the number of MODIS images available for this period. This is especially true during the month of October, for which there was on average half as many MODIS images without full cloud cover than between May and September. The variables describe what can be considered as an annual-based phenology, compiling days with less than 25% cloud cover and for which remotely sensed Chl-a was above the established threshold, for any given pixel.A geo-referenced database of 17 morphological, physiographic, and climatic characteristics of the watershed of each studied lake was established. The boundaries and morphological descriptors of the watersheds (area, slope) were calculated from the Canadian Digital Elevation Model with a spatial resolution of approximately 30 m. Climate data were calculated from North American Regional Reanalyses with a spatial resolution of approximately 32 km. The cumulative degree-days (°C day) was calculated by summing the recorded degrees (°C) each day above 20°C, considered as a threshold for cyanobacterial growth. Even though the remote sensing approach used here is not specific to cyanobacterial biomass, this climate proxy is considered valid since algal growth in general is stimulated by warm waters. Land use data (at 40 m spatial resolution) as well as agricultural and ecumene data (at 25 m spatial resolution) were provided by Natural Resources Canada. The environmental indicators were considered stationary over the period 2000–2016

Spatiotemporal data of algal blooms phenology

The spatio-temporal data contain annual phytoplankton bloom phenology from 2000 to 2016 on 580 lakes located in the province of Quebec, Canada, between 44 and 50°N and 67 and 80°W. The data include height phenological variables related to phytoplankton blooms, and 17 physiographical, morphological, and climatic descriptors of the lake and the watershed. For each studied year, phenological variables were established as follows: (1) the frequency (the number of days when Chl-a concentrations remained above the threshold), (2) the intensity (the maximum concentration of Chl-a detected during a bloom), (3) the relative area (the maximum area occupied by a bloom normalized by the lake area), (4) the onset date and (5) the end date (respectively, the first and last day of the year when a bloom was detected), and (6) the duration (the number of days between the onset date and the end date). Remote sensing determination of the end date and duration of blooms is challenging because the studied region is frequently covered by clouds during the fall, significantly reducing the number of MODIS images available for this period. This is especially true during the month of October, for which there was on average half as many MODIS images without full cloud cover than between May and September. The variables describe what can be considered as an annual-based phenology, compiling days with less than 25% cloud cover and for which remotely sensed Chl-a was above the established threshold, for any given pixel.A geo-referenced database of 17 morphological, physiographic, and climatic characteristics of the watershed of each studied lake was established. The boundaries and morphological descriptors of the watersheds (area, slope) were calculated from the Canadian Digital Elevation Model with a spatial resolution of approximately 30 m. Climate data were calculated from North American Regional Reanalyses with a spatial resolution of approximately 32 km. The cumulative degree-days (°C day) was calculated by summing the recorded degrees (°C) each day above 20°C, considered as a threshold for cyanobacterial growth. Even though the remote sensing approach used here is not specific to cyanobacterial biomass, this climate proxy is considered valid since algal growth in general is stimulated by warm waters. Land use data (at 40 m spatial resolution) as well as agricultural and ecumene data (at 25 m spatial resolution) were provided by Natural Resources Canada. The environmental indicators were considered stationary over the period 2000–2016.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Effect of intense pulsed light treatment on human skin in vitro : analysis of immediate effects on dermal papillae and hair follicle stem cells

Background : Hair follicles house a permanent pool of epithelial stem cells. Intense pulsed light (IPL) sources have been successfully used for hair removal, but long-term hair reduction may require several treatments. Many questions remain regarding the impact of IPL treatment on the structure of the hair follicle, more specifically on hair follicular stem cells and dermal papilla cells, a group of specialized cells that orchestrate hair growth. Objectives : To characterize the destruction of human hair follicles and surrounding tissues following IPL treatment, with more attention paid to the bulge and the bulb regions. Methods : Human scalp specimens of Fitzpatrick skin phototype II were exposed ex vivo to IPL pulses and were then processed for histological analysis, immunodetection of stem cell-associated keratin 19, and revelation of the endogenous alkaline phosphatase activity expressed in dermal papilla cells. Results : Histological analysis confirmed that pigmented structures, such as the melanin-rich matrix cells of the bulb in anagen follicles and the hair shaft, are principally targeted by IPL treatment, while white hairs and epidermis remained unaffected. Damage caused by heat sometimes extended over the dermal papilla cells, while stem cells were mostly spared. Conclusions : IPL epilation principally targets pigmented structures. Our results suggest that, under the tested conditions, collateral damage does not deplete stem cells. Damage at the dermal papilla was observed only with high-energy treatment modalities. Extrapolated to frequently treated hairs, these observations explain why some hairs grow back after a single IPL treatment

Degassing during magma ascent in the Mule Creek vent (USA).

The structures and textures of the rhyolite in the Mule Creek vent (New Mexico, USA) indicate mechanisms by which volatiles escape from silicic magma during eruption. The vent outcrop is a 300-m-high canyon wall comprising a section through the top of a feeder conduit, vent and the base of an extrusive lava dome. Field relations show that eruption began with an explosive phase and ended with lava extrusion. Analyses of glass inclusions in quartz phenocrysts from the lava indicate that the magma had a pre-eruptive dissolved water content of 2.5–3.0 wt% and, during eruption, the magma would have been water-saturated over the vertical extent of the present outcrop. However, the vesicularity of the rhyolite is substantially lower than that predicted from closed-system models of vesiculation under equilibrium conditions. At a given elevation in the vent, the volume fraction of primary vesicles in the rhyolite increases from zero close to the vent margin to values of 20–40 vol.% in the central part. In the centre the vesicularity increases upward from approximately 20 vol.% at 300 m below the canyon rim to approximately 40 vol.% at 200 m, above which it shows little increase. To account for the discrepancy between observed vesicularity and measured water content, we conclude that gas escaped during ascent, probably beginning at depths greater than exposed, by flow through the vesicular magma. Gas escape was most efficient near the vent margin, and we postulate that this is due both to the slow ascent of magma there, giving the most time for gas to escape, and to shear, favouring bubble coalescence. Such shear-related permeability in erupting magma is supported by the preserved distribution of textures and vesicularity in the rhyolite: Vesicles are flattened and overlapping near the dense margins and become progressively more isolated and less deformed toward the porous centre. Local zones have textures which suggest the coalescence of bubbles to form permeable, collapsing foams, implying the former existence of channels for gas migration. Local channelling of gas into the country rocks is suggested by the presence of sub-horizontal syn-eruptive rhyolitic tuffisite veins which depart from the vent margin and invade the adjacent country rock. In the central part of the vent, similar local channelling of gas is indicated by steep syn-eruption tuffisite veins which cut the rhyolite itself. We conclude that the suppression of explosive eruption resulted from gas separation from the ascending magma and vent structure by shear-related porous flow and channelling of gas through tuffisite veins. These mechanisms of gas loss may be responsible for the commonly observed transition from explosive to effusive behaviour during the eruption of silicic magma

Financing of Women-Owned Ventures: The Impact of Gender and Other Owner- and Firm-Related Variables

While women-owned ventures represent an increasing proportion of new businesses in most western countries, most of them have particular financing patterns and encounter barriers in their access to financing. Recent research on the question argues that barriers to financing are mainly dependent on factors other than gender, such as owner- and firm-related characteristics. This quantitative and qualitative study, through descriptive statistics and interview analysis, examines the relationship between financing patterns and barriers and gender from the woman entrepreneur’s viewpoint. It explores the behaviours and representations of women entrepreneurs towards financing, and considers to what extent the women see their own approaches as being different from those of men. Our study suggests that a gender effect still exists, and tries to identify its location and the corresponding implications for further research and action.Programme Equal 2003-2005 - Projet Diane: Les femmes entrepreneures face à la formation, au financement et aux réseau