ALBERT

Description: Abstract Microalgae contribute ~ 50% to global primary production, most of which is consumed by protozoa. Determining the thermal‐sensitivity of this trophic interaction is, therefore, fundamental to predicting impacts of climate change. Here, we question the application of current predictive approaches. Thermal responses are commonly described by the Arrhenius function: , where r is a rate (e.g., growth), A is a scaling factor, Ea is the activation energy, k is the Boltzmann‐constant, and T is absolute temperature. The influential metabolic theory of ecology (MTE) proposes that estimates of Ea for heterotrophs and autotrophs are 0.65 eV and 0.32 eV, respectively; when applied to specific growth rate of algae and protozoa, this difference has significant predictive consequences. Through literature review and statistical evaluation, we show that the MTE predictions do not apply to taxon‐specific responses of protozoa (n = 103) or algae (n = 183), with mean Ea of 0.71 eV (95% confidence interval [CI]: 0.69–0.74) and 0.61 eV (95% CI: 0.58–0.63), respectively. To obtain these, we fitted a series of models where Ea was constant within a defined group (e.g., protozoa), and the amplitude A depended on the individual responses within the group. Then, by applying the MTE and our predictions to a generic protozoan‐algal, predator‐prey model we show that: (1) the “canonical” MTE values lead to misrepresenting productivity by several fold; (2) a general response encompassing both groups (0.69 eV) should suffice for such models; and (3) applying our new responses has substantial effects on algal‐protozoan population dynamics over temperature shifts of ~ 5°C.

Description: Abstract Mn‐doped HgO nanostructured thin films (Hg1‐xMnxO) have been prepared using electron beam evaporation technique on Corning glass (1022) substrate at room temperature with different concentrations x = 0, 0.015, 0.05, 0.1, 0.15, and 0.2. The microstructural, morphological, semiconducting, and optoelectronic properties of the films have been investigated. The X‐ray diffraction spectra suggest a hexagonal wurtzite type structure with lattice parameters decreased with increasing Mn content. It was found that the average particle size of the films decreases with increasing Mn doping which is confirmed by FE‐SEM and AFM micrographs. The optical band gap of the investigated Mn‐doped HgO nanocrystalline films is determined from the absorption coefficient and found to increase with the increase of Mn concentration which is attributed to the sp‐d exchange interaction and/or the quantum confinement effect. The refractive index and extinction coefficient of the Mn‐doped HgO films are also reported. The refractive index dispersion n(λ) is analyzed by single‐effective‐oscillator dispersion model proposed by the Wemple–DiDomenico (WDD). The oscillator parameters were estimated. The obtained dispersion values are suitable for the design of optoelectronic devices.

Description: Water vapour measurements from a ground-based Raman lidar and an airborne differential absorption lidar, complemented by high resolution numerical simulations from two mesoscale models (AROME-WMED and Meso-NH), are considered to investigate three transition events from Mistral/Tramontane to southerly marine flow taking place in the Montpellier region (Southern France) in the time frame September-October 2012, during the Hydrological Cycle in the Mediterranean Experiment Special Observation Period 1. Low-level wind reversals associated with these transitions are found to have a strong impact on water vapour transport, leading to a large variability of the water vapour vertical and horizontal distributions. Water vapour mixing ratio within the boundary layer is found to vary from typical values in the range 4–8 g kg −1 during the northerly Mistral/Tramontane flows to values in the range 8–15 g kg −1 during the southerly marine flows. The increase/decrease in water vapour mixing ratio within the boundary layer may be abrupt and marked during these transition periods, with values increasing-decreasing by a factor of 2 to 4 within 1 hour. The high spatial and temporal resolutions of the lidar data allow monitoring the time evolution of the water vapour field during these transitions from predominantly northerly Mistral/Tramontane flow to a predominantly southerly flow, permitting to identify the quite sharp separation between these flows, which is also satisfactorily well captured by the mesoscale models. Water vapour measurements from the ground-based lidar are complemented by particle backscatter measurements from the same system, which allow also revealing the significant variability in the aerosol and cloud fields associated with these transition events.

Description: How temperate forests will respond to climate change is uncertain; projections range from severe decline to increased growth. We conducted field tests of sessile oak ( Quercus petraea), a widespread keystone European forest tree species, including more than 150,000 trees sourced from 116 geographically diverse populations. The tests were planted on 23 field sites in six European countries, in order to expose them to a wide range of climates, including sites reflecting future warmer and drier climates. By assessing tree height and survival, our objectives were twofold: (1) to identify the source of differential population responses to climate (genetic differentiation due to past divergent climatic selection versus plastic responses to ongoing climate change), (2) to explore which climatic variables (temperature or precipitation) trigger the population responses. Tree growth and survival were modeled for contemporary climate and then projected using data from four regional climate models for years 2071-2100, using two greenhouse gas concentration trajectory scenarios each. Overall results indicated a moderate response of tree height and survival to climate variation, with changes in dryness (either annual or during the growing season) explaining the major part of the response. Whilst, on average, populations exhibited local adaptation, there was significant clinal population differentiation for height growth with winter temperature at the site of origin. The most moderate climate model (HIRHAM5-EC; rcp4.5) predicted minor decreases in height and survival, whilst the most extreme model (CCLM4-GEM2-ES; rcp8.5) predicted large decreases in survival and growth for southern and southeastern edge populations (Hungary and Turkey). Other non-marginal populations with continental climates were predicted to be severely and negatively affected (Bercé, France), while populations at the contemporary northern limit (colder and humid maritime regions; Denmark and Norway) will probably not show large changes in growth and survival in response to climate change. This article is protected by copyright. All rights reserved.

Description: Large wild ungulates are a major biotic factor shaping plant communities. They influence species abundance and occurrence directly by herbivory and plant dispersal, or indirectly by modifying plant-plant interactions and through soil disturbance. In forest ecosystems, researchers’ attention has been mainly focused on deer overabundance. Far less is known about the effects on understory plant dynamics and diversity of wild ungulates where their abundance is maintained at lower levels to mitigate impacts on tree regeneration. We used vegetation data collected over ten years on 82 pairs of exclosure (excluding ungulates) and control plots located in a nation-wide forest monitoring network (Renecofor). We report the effects of ungulate exclusion on (i) plant species richness and ecological characteristics, (ii) and cover percentage of herbaceous and shrub layers. We also analysed the response of these variables along gradients of ungulate abundance, based on hunting statistics, for wild boar ( Sus scrofa ) , red deer ( Cervus elaphus ) and roe deer ( Capreolus capreolus ). Outside the exclosures, forest ungulates maintained a higher species richness in the herbaceous layer (+15%), while the shrub layer was 17% less rich, and the plant communities became more light-demanding. Inside the exclosures, shrub cover increased, often to the benefit of bramble ( Rubus fruticosus agg.). Ungulates tend to favour ruderal, hemerobic, epizoochorous and non-forest species. Among plots, the magnitude of vegetation changes was proportional to deer abundance. We conclude that ungulates, through the control of the shrub layer, indirectly increase herbaceous plant species richness by increasing light reaching the ground. However, this increase is detrimental to forest-specialist species, and contributes to a landscape-level biotic homogenisation. Even at population density levels considered to be harmless for overall plant species richness, ungulates remain a conservation issue for plant community composition. This article is protected by copyright. All rights reserved.

Description: Background Dentin hypersensitivity is an important clinical problem affecting a large percentage of the population, and various therapies have been suggested for its treatment—among them desensitizing agents and lasers. The aim of this study was to evaluate the in vitro effects of different in-office desensitizing agents and different type lasers, alone or in combination, on human dentinal tubules. Materials and Methods Eighty-four dentinal specimens obtained from freshly extracted impacted third molars were included and subsequently divided into seven groups: Group 1 (Control), Group 2 (Gluma desensitizer), Group 3 (Teethmate desensitizer), Group 4 (Nd:YAG laser), Group 5 (Er:YAG laser), Group 6 (Gluma desensitizer + Er:YAG laser), and Group 7 (Teethmate desensitizer + Er:YAG laser). The dentinal specimens of all groups were evaluated using SEM. A total of 12 images per sample were taken, and the numbers of open, partially occluded, and totally visible (open + partially occluded) dentinal tubules were counted. AFM was used to further substantiate the blocking mechanism. The data were analyzed by one-way ANOVA and Dunnett-C tests. Results Comparison of the number of occluded dentinal tubules per 100 µm 2 revealed that the laser and laser combined-treated groups showed the most occluded dentinal tubules. Gluma desensitizer + Er:YAG laser combination demonstrated significantly more tubule occlusion than all the other groups ( p  〈 .05). Conclusions The results of this study show that combined treatment methods were effective in the occlusion of dentinal tubules.

Description: A realistic simulation of the Atlantic Multidecadal Variability (AMV) and related teleconnections is essential to resolve and understand the potential predictability over Europe at decadal time-scale. Based on a large ensemble of state-of-the-art climate models, we show that a considerable inter-model spread exists in the spatio-temporal properties of the simulated AMV and teleconnections with European summer temperature. The greater the persistence, variance and basin-scale spatial coherence, the stronger the teleconnection. We demonstrate that only a few members of a few models produce a teleconnection that is consistent with observational estimates over the instrumental period. This highlights the possible extreme nature of the last century teleconnection and/or a detrimental underestimation of ocean-land teleconnectivity in many climate models. Yet, we emphasize the considerable uncertainties due to methods used to disentangle internal and externally forced variations in observations, and to sampling, which must be correctly accounted when analyses are performed on short temporal records.

Description: In Boulanger et al . (2018), we assessed the role of ungulates’ presence on short-term understory plant dynamics, using a nationwide network composed of paired exclosure-control plots. We demonstrated that ungulates are key drivers of understory vegetation in managed forests since they alter the richness and abundance of the shrub layer, increase the richness of the herb layer and favour open habitat plant species. Our results show that local scale mechanisms, here involving indirect facilitation, lead to global dynamics in forest-ungulate systems. Our conclusions underline that an increase in species richness, often simplistically viewed as a positive change in ecosystems, can alter the community composition and thus requires a more subtle interpretation regarding conservation issues. This article is protected by copyright. All rights reserved.

Description: ABSTRACT The climate of Morocco is characterized by a strong spatial and inter-annual variability. This study provides an evaluation of high-resolution regional climate model (RCM) simulations of precipitation and temperature over Morocco and future projections based on two emission scenarios. The evaluation of the RCM ensemble over the historical period is performed with a network of 20 weather stations, using Taylor and Portrait diagrams. The results show that the four simulations considered (CLM, CNRM, KNMI and IPSL) are generally able to simulate climate indices and no model is performing significantly better. This ensemble of RCM simulations captures the precipitation and temperature spatiotemporal patterns in the evaluation and historical runs. Climate change scenarios are presented with the goal to identify spatial patterns of change over Morocco, to provide information for climate policy and adaptation. The RCP4.5 and RCP8.5 emission scenarios are considered for two time horizons, 2036–2065 and 2066–2095. A large increase in temperature is observed by the end of the century in particular for the RCP8.5 scenario over the Southeast regions. The minimum temperature is expected to increase more than maximum temperature in most parts of Morocco, with the exception of the Eastern regions. The different RCMs show a strong agreement towards similar changes for most temperature-based indices. The climate change signal is less homogeneous in the different simulations for most of the precipitation indices. Nevertheless, there is a clear decrease of precipitation totals in the different simulations, following a north to south gradient. However, for heavy rainfall events, there are strong uncertainties in projections and the four RCM simulations disagree about the future changes. Study area and geographical locations of the 20 SYNOP weather stations used in the study and the gauge-based spatial distribution of annual precipitation during the 1981–2010 period. (Source: Maroc-Météo.)

Description: ABSTRACT Tomentosin, a natural sesquiterpene lactone purified from of Inula viscosa L., was investigated for its anti-proliferative, telomere shortening and apoptotic effects on human cervical cancer HeLa and SiHa cell lines. Tomentosin was found to inhibit the growth of SiHa and HeLa cell lines in dose and time-dependent manner (IC 50 values of 7.10 ± 0.78µM and 5.87 ± 0.36µM, respectively after 96h of treatment). As evidenced by TTAGGG telomere length assay, tomentosin target specifically the telomeric overhang lengthening. This was confirmed by the evaluation of the cytotoxic effects of tomentosin in the foetal fibroblast Wi38 and JW10 cells which were derived from Wi38 and express hTERT, the telomerase catalytic subunit. We found that JW10 cells are 4.7-fold more sensitive to tomentosin which argues for telomere as its specific target. Furthermore, we found that tomentosin mediate this cytotoxic effect by inducing apoptosis and cell cycle arrest at G2/M phase. Morphological features of treated cells, as evidenced by Hoechst 33324 staining, revealed that the cytotoxic effect was due to induction of apoptosis. This was accompanied by pro-caspase-3 cleavage, an increase in caspase-3 activity and a cleavage of poly (ADP-ribose) polymerase (PARP). Moreover, tomentosin induced a decrease in mitochondrial membrane potential (Δ Ψm ) and an increase in reactive oxygen species (ROS), accompanied by a decrease in Bcl-2 expression. This indicates that tomentosin-induced apoptosis may involve a mitochondria-mediated signaling pathway. This study provides the first evidence that tomentosin targets telomere machinery and induces apoptosis in cervical cancer cells. The molecular mechanism underlying tomentosin-induced apoptosis may involve a mitochondria-mediated signaling pathway. This article is protected by copyright. All rights reserved