Salinity effects on germination, growth and mineral nutrition of Ricinus communis seedlings

The salinity effects on the germination and the growth of greenhouse grown castor bean (Ricinus communis L.) from three local provenances (Sidi Thabet, Grombalia and Kairouan) were studied. Plants were grown in sand-perlite mixture and irrigated with solution containing 0, 2, 5, and 10 g/l NaCl. The effect of salt stress on germination was weakly pronounced in the case of castor bean for the three provenances compared to control. Moreover, salt stress induced significant differences on plant growth during the experimental period. After 80 stress days, decreases in plant height were observed. 10 g/l NaCl has an intense depressive effect on seedling stage. The seedlings have not completed their development and this is noticed for all provenances. 5 g/l NaCl has also an intense depressive effect only for Grombalia. With regards to the mineral nutrition, hypocotyls are more concentrated in Na+ and Cl− than the other organs. Thus, we observed a slight increase in K+ concentration for 2 and 5 g/l NaCl compared to control, especially for Kairouan in stems. Based on the stability of the tolerance to salinity from germinative stage to seedlings stage, the provenance of Kai rouan was identified as the most tolerant and the provenance of Grombalia as the most sensitive to salt toxicity

Influence of the drought on antioxidant and enzymatic activities of two Pinus species in humid and sub-humid climate

Pinus genus is widespread in the Mediterranean region and the most common in Tunisia. The impact of high temperatures in the mid-summer period (July 2015 and July 2016) on phenols and biological properties were examined in vitro. The study was carried out in two arboreta, in humid and sub-humid climates, dry needles of Pinus pinea and Pinus pinaster were used for secondary metabolites, antioxidant activities, and enzymatic inhibitory activities. The amount of all measured parameters increased from 2015 to 2016 in the two pine species in the two arboreta. Pinus pinea produced more phenols and showed higher antioxidant activity and a-amylase and lipoxygenase inhibitory activities than Pinus pinaster. Besides, both species generally presented better biological activities and higher phenol amounts in 2016 than in 2015, being 2016 warmer and drier than 2015 in both harvest zones. It was evident that both species in every bioclimatic zones adapted to the new climate conditions producing more secondary metabolites that rendered better antioxidant and inhibitory enzymatic activities. These findings confirmed the impact of mid-summer water deficits on pine species in the context of climate change and help to select the most resistant species for future reforestation.info:eu-repo/semantics/publishedVersio

Development of a cost-effective optical sensor for continuous monitoring of turbidity and suspended particulate matter in marine environment

A cost-effective optical sensor for continuous in-situ monitoring of turbidity and suspended particulate matter concentration (SPM), with a production cost in raw materials less than 20 €, is presented for marine or fluvial applications. The sensor uses an infrared LED and three photodetectors with three different positions related to the light source-135º, 90º and 0º-resulting in three different types of light detection: backscattering, nephelometry and transmitted light, respectively. This design allows monitoring in any type of environment, offering a wide dynamic range and accuracy for low and high turbidity or SPM values. An ultraviolet emitter-receiver pair is also used to differentiate organic and inorganic matter through the differences in absorption at different wavelengths. The optical transducers are built in a watertight structure with a radial configuration where a printed circuit board with the electronic signal coupling is assembled. An in-lab calibration of the sensor was made to establish a relation between suspended particulate matter (SPM) or the turbidity (NTU) to the photodetectors' electrical output value in Volts. Two different sizes of seashore sand were used (180 µm and 350 µm) to evaluate the particle size susceptibility. The sensor was tested in a fluvial environment to evaluate SPM change during sediment transport caused by rain, and a real test of 22 days continuous in-situ monitoring was realized to evaluate its performance in a tidal area. The monitoring results were analysed, showing the SPM change during tidal cycles as well as the influence of the external light and biofouling problems.Funding Agency Programa Operacional Regional do Norte (NORTE2020), through Fundo Europeu de Desenvolvimento Regional (FEDER) NORTE-01-0145-FEDER-000032 European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalizacao), project ICT UID/GEO/04683/2013 POCI-01-0145-FEDER-007690 Fundacao para a Ciencia e a Tecnologia (FCT)info:eu-repo/semantics/publishedVersio

Epigenetic gestational age acceleration:A prospective cohort study investigating associations with familial, sociodemographic and birth characteristics

Abstract Background Gestational age at delivery is associated with health and social outcomes. Recently, cord blood DNA methylation data has been used to predict gestational age. The discrepancy between gestational age predicted from DNA methylation and determined by ultrasound or last menstrual period is known as gestational age acceleration. This study investigated associations of sex, socioeconomic status, parental behaviours and characteristics and birth outcomes with gestational age acceleration. Results Using data from the Avon Longitudinal Study of Parents and Children (n = 863), we found that pre-pregnancy maternal overweight and obesity were associated with greater gestational age acceleration (mean difference = 1.6 days, 95% CI 0.7 to 2.6, and 2.9 days, 95% CI 1.3 to 4.4, respectively, compared with a body mass index < 25 kg/m2, p < .001). There was evidence of an association between male sex and greater gestational age acceleration. Greater gestational age acceleration was associated with higher birthweight, birth length and head circumference of the child (mean differences per week higher gestational age acceleration: birthweight 0.1 kg, 95% CI 0.1 to 0.2, p < .001; birth length 0.4 cm, 95% CI 0.2 to 0.7, p < .001; head circumference 0.2 cm, 95% CI 0.1 to − 0.4, p < .001). There was evidence of an association between gestational age acceleration and mode of delivery (assisted versus unassisted delivery, odds ratio = 0.9 per week higher gestational age acceleration, 95% CI 0.7, 1.3 (p = .05); caesarean section versus unassisted delivery, odds ratio = 0.6, 95% CI 0.4 to 0.9 per week higher gestational age acceleration (p = .05)). There was no evidence of association for other parental and perinatal characteristics. Conclusions The associations of higher maternal body mass index and larger birth size with greater gestational age acceleration may imply that maternal overweight and obesity is associated with more rapid development of the fetus in utero. The implications of gestational age acceleration for postnatal health warrant further investigation

Differences in the pattern and regulation of mineral deposition in human cell lines of osteogenic and non-osteogenic origin

Bone marrow-derived mesenchymal stem cells (MSCs) are widely used as a cellular model of bone formation, and can mineralize in vitro in response to osteogenic medium (OM). It is unclear, however, whether this property is specific to cells of mesenchymal origin. We analysed the OM response in 3 non-osteogenic lines, HEK293, HeLa and NTera, compared to MSCs. Whereas HEK293 cells failed to respond to OM conditions, the 2 carcinoma-derived lines NTera and HeLa deposited a calcium phosphate mineral comparable to that present in MSC cultures. However, unlike MSCs, HeLa and NTera cultures did so in the absence of dexamethasone. This discrepancy was confirmed, as bone morphogenetic protein inhibition obliterated the OM response in MSCs but not in HeLa or NTera, indicating that these 2 models can deposit mineral through a mechanism independent of established dexamethasone or bone morphogenetic protein signalling