Response of peat biogeochemistry and soil organic matter quality to rewetting in bogs and spruce swamp forests

Various peatland restoration strategies developed during the last two decades have aimed to stop degradation and bring back the original hydrology, biodiversity and other peatland functions. This study evaluated progress 6-15 years after rewetting in vegetation development, physicochemical properties of peat, soil organic matter (SOM) quality and microbial activity in previously long-term drained bogs and spruce swamp forests (SSF) in comparison with pristine and long-term drained sites in the Bohemian Forest, Czech Republic. Long-term drainage led to overall ecosystem degradation, indicated by a change in vegetation composition, reduced decomposability of peat, with high content of recalcitrant compounds and decreased pH, and reduced soil microbial biomass and activity. The degradation was more pronounced in SSF, while bogs seemed to be relatively resistant to environmental changes caused by drainage. Post-rewetting progress has occurred with regard to vegetation composition, peat pH, microbial biomass and potential anaerobic CO2 and CH4 production, all of which tending towards characteristics of the pristine sites. However, overall SOM quality has not yet responded significantly, indicating that some peat properties and functions, such as C accumulation, need much longer periods of time to return to the original level.Peer reviewe

Using three-dimensional digital models to establish alveolar morphotype

Background: The aim of the study was to propose a classification of alveolar morphotype and assess a relationship between extraction/non-extraction orthodontic treatment and changes to the alveolar process.Materials and methods: Seventy-five subjects (mean age = 23.2, SD = 5.1) were selected. Areas of the sections of the alveolar process (ASAP) at three different levels (0, 2, and 4 mm) were measured on pre- and post-treatment three-dimensional digital models. Method reliability was analysed using Dahlberg’s formula, intraclass correlation coefficient, and paired t-tests.Results: The mean ASAP was smallest at level 0 and largest at level 4. Pre-treatment ASAP < 773 mm2, < 863.9 mm2, and < 881.1 mm2 at levels 0, 2, and 4 mm, respectively, should be described as a “thin” alveolar morphotype. Regression models showed that pre-treatment ASAP was a predictor of the change of the alveolus during treatment only at level 2.Conclusions: Patients for whom pre-treatment ASAP is < 773 mm2, < 863.9 mm2, and < 881.1 mm2 at levels 0, 2, and 4 mm, respectively, should be described as having a “thin” alveolar morphotype. In these patients, extraction treatment, associated with a decrease in the alveolus area, should be exercised with caution

PROGRAMME DE DATATIONS DES FONDATIONS DU CHATEAU GRIMALDI, MUSEE PICASSO, ANTIBES. Rapport scientifique final auprès de la mairie d'Antibes, janvier 2016

Dans le cadre d’un programme archéologique dirigé par Eric Delaval sur les fondations du Château Grimaldi, l'IRAMAT-CRP2A est intervenu afin de dater les structures architecturales correspondantes par des méthodes physiques. Une intervention des membres de l'IRAMAT-CRP2A a eu lieu en décembre 2012. Elle a permis d'échantillonner des terres cuites (briques) et 5 échantillons de mortier de blocage et de jointoiement pour la datation par luminescence, ainsi que 92 échantillons de briques pour la datation par archéomagnétisme.Les objectofs de ce travail sont à la fois archéologiques et méthodologiques :- Dater la construction du mur de fondation grâce aux terres cuites architecturales dont on a envisagé de déterminer la datation de la production à partir des données d’archéomagnétisme et de luminescence.- Mettre en place la datation des mortiers par OSL monograin, en comparant les datations obtenues avec celles de terres cuites architecturales.Les résultats obtenus par le couplage entre l'archéomagnétisme des terres cuites et l'OSL des mortiers montrent que les fondations gallo-romaines du château Grimaldi (actuel Musée Picasso) ont été construites dans l'intervalle 30-220 AD (à 95% de probabilité) avec une médiane située vers 100 AD. Sur le plan méthodologique, il s'agit de la première datation de mortiers par OSL single grain véritablement aboutie

Do We Have a Proper Model?

It has been reported recently that the cystic fibrosis transmembrane conductance regulator (CFTR) besides transcellular chloride transport, also controls the paracellular permeability of bronchial epithelium. The aim of this study was to test whether overexpressing wtCFTR solely regulates paracellular permeability of cell monolayers. To answer this question we used a CFBE41o– cell line transfected with wtCFTR or mutant F508del-CFTR and compered them with parental line and healthy 16HBE14o– cells. Transepithelial electrical resistance (TER) and paracellular fluorescein flux were measured under control and CFTR-stimulating conditions. CFTR stimulation significant decreased TER in 16HBE14o– and also in CFBE41o– cells transfected with wtCFTR. In contrast, TER increased upon stimulation in CFBE41o– cells and CFBE41o– cells transfected with F508del-CFTR. Under non-stimulated conditions, all four cell lines had similar paracellular fluorescein flux. Stimulation increased only the paracellular permeability of the 16HBE14o– cell monolayers. We observed that 16HBE14o– cells were significantly smaller and showed a different structure of cell-cell contacts than CFBE41o– and its overexpressing clones. Consequently, 16HBE14o– cells have about 80% more cell-cell contacts through which electrical current and solutes can leak. Also tight junction protein composition is different in ‘healthy’ 16HBE14o– cells compared to ‘cystic fibrosis’ CFBE41o– cells. We found that claudin-3 expression was considerably stronger in 16HBE14o– cells than in the three CFBE41o– cell clones and thus independent of the presence of functional CFTR. Together, CFBE41o– cell line transfection with wtCFTR modifies transcellular conductance, but not the paracellular permeability. We conclude that CFTR overexpression is not sufficient to fully reconstitute transport in CF bronchial epithelium. Hence, it is not recommended to use those cell lines to study CFTR-dependent epithelial transport

Comparison of planar DMSA scan with an evaluation based on SPECT imaging in the split renal function assessment

BACKGROUND: Validation of the 99mTc-DMSA planar scintigraphy accuracy for split renal function assessment and comparison with evaluation based on SPECT imaging both with and without CT attenuation correction. MATERIALS AND METHODS: For split renal function assessment two methods were used: A) planar scintigraphy based on anterior and posterior projections using correction for kidney depth calculated by the geometric mean; B) semi-quantitative evaluation based on SPECT (B1) and attenuation-corrected SPECT/CT (B2) images using locally developed software for kidney segmentation and voxel-based analysis. All three methods were performed with a phantom simulating body including pair of kidneys. For patient study methods A and B1 were applied on a group of 140 children and adolescents with various renal diseases. Renal function ratios were compared both mutually and with physically measured activity ratios in the phantom. RESULTS: Method A provided results which were closest to measured reference values (average absolute difference of 0.9 percentage points [pp]). Method B1 was noticeably worse (2.1pp), whereas attenuation correction (B2) improved tomography results considerably (1.3 pp). The superiority of planar imaging could be caused among others by differences in creation of planar range of interest compared to tomographic volume of interest. However all the differences were under the threshold of any clinical importance. The comparison between method A and B1 based on patient study also showed differences mostly of none clinical importance. CONCLUSION: Routine evaluation of split renal function using planar technique with correction of the kidney depth is at least equivalent to tomographic evaluation, and there is no need to update the established clinical practice.    BACKGROUND: Validation of the 99mTc-DMSA planar scintigraphy accuracy for split renal function assessment and comparison with evaluation based on SPECT imaging both with and without CT attenuation correction. MATERIALS AND METHODS: For split renal function assessment two methods were used: A) planar scintigraphy based on anterior and posterior projections using correction for kidney depth calculated by the geometric mean; B) semi-quantitative evaluation based on SPECT (B1) and attenuation-corrected SPECT/CT (B2) images using locally developed software for kidney segmentation and voxel-based analysis. All three methods were performed with a phantom simulating body including pair of kidneys. For patient study methods A and B1 were applied on a group of 140 children and adolescents with various renal diseases. Renal function ratios were compared both mutually and with physically measured activity ratios in the phantom. RESULTS: Method A provided results which were closest to measured reference values (average absolute difference of 0.9 percentage points [pp]). Method B1 was noticeably worse (2.1pp), whereas attenuation correction (B2) improved tomography results considerably (1.3 pp). The superiority of planar imaging could be caused among others by differences in creation of planar range of interest compared to tomographic volume of interest. However all the differences were under the threshold of any clinical importance. The comparison between method A and B1 based on patient study also showed differences mostly of none clinical importance. CONCLUSION: Routine evaluation of split renal function using planar technique with correction of the kidney depth is at least equivalent to tomographic evaluation, and there is no need to update the established clinical practice

Does Life Satisfaction Mediate the Association between Socioeconomic Status and Excessive Internet Use?

Excessive Internet use is becoming a rapidly increasing problem in today's society. Our aim was to assess the association between socioeconomic status (SES) of the family and excessive Internet use (EIU), and whether life satisfaction mediates this association. We analyzed data from a representative sample of 2844 Slovak adolescents (mean age 14.34, 50.5% boys) from the 2014 Health Behavior in School aged Children (HBSC) study, based on self-report questionnaires. We assessed the association of SES, measured by several indicators, such as perceived family wealth, parental education, and (un)employment, and adolescent EIU using linear regression, adding life satisfaction as a mediator. Adolescents whose father was unemployed and whose perceived family wealth was low tended to score higher on EIU. Neither gender nor age affected this relationship. Life satisfaction mediated a part of the association between SES and EIU in the case of low perceived family wealth and father's (un)employment. Adolescents with a low SES are more likely to become excessive Internet users, and life satisfaction mediates this association. Prevention of EIU among adolescents should be targeted at those with low SES, with life satisfaction being the topic to address

Blunted glucocorticoid and mineralocorticoid sensitivity to stress in people with diabetes.

Psychological stress may contribute to type 2 diabetes but mechanisms are still poorly understood. In this study, we examined whether stress responsiveness is associated with glucocorticoid and mineralocorticoid sensitivity in a controlled experimental comparison of people with type 2 diabetes and non-diabetic participants. Thirty-seven diabetes patients and 37 healthy controls underwent psychophysiological stress testing. Glucocorticoid (GR) and mineralocorticoid sensitivity (MR) sensitivity were measured by dexamethasone- and prednisolone-inhibition of lipopolysaccharide (LPS)-induced interleukin (IL) 6 levels, respectively. Blood pressure (BP) and heart rate were monitored continuously, and we periodically assessed salivary cortisol, plasma IL-6 and monocyte chemotactic protein (MCP-1). Following stress, both glucocorticoid and mineralocorticoid sensitivity decreased among healthy controls, but did not change in people with diabetes. There was a main effect of group on dexamethasone (F(1,74)=6.852, p=0.013) and prednisolone (F(1,74)=7.295, p=0.010) sensitivity following stress at 45 min after tasks. People with diabetes showed blunted stress responsivity in systolic BP, diastolic BP, heart rate, IL-6, MCP-1, and impaired post-stress recovery in heart rate. People with Diabetes had higher cortisol levels as measured by the total amount excreted over the day and increased glucocorticoid sensitivity at baseline. Our study suggests that impaired stress responsivity in type-2 diabetes is in part due to a lack of stress-induced changes in mineralocorticoid and glucocorticoid sensitivity

Adolescents exposed to discrimination:are they more prone to excessive internet use?

BACKGROUND: The Internet may serve as a suitable environment for discriminated adolescents as they may consider the online space as the place where they have possibility to build social ties they are missing in their offline life or manage their self-presentation. Therefore, our aim was to explore the association between different types of discrimination by peers (because of gender, physical appearance, culture/skin color/language, unfavorable family situation) and excessive Internet use (EIU), and whether gender moderates this association. METHODS: We used data from a representative sample of 6,462 Slovak adolescents (mean age: 13.00, 49.6% boys) from the HBSC study conducted in 2018. Data were collected through online self-reported questionnaires. We assessed the association between various types of discrimination by peers and EIU using linear regression, and the role of gender as potential moderator. RESULTS: Discrimination because of physical appearance was most prevalent (18.0%). Adolescents exposed to discrimination by peers reported higher levels of EIU. We found an interaction of gender on the association of discrimination because unfavorable family situation with EIU. Boys who experienced this type of discrimination were at higher risk of EIU compared to girls. CONCLUSION: Discriminated adolescents are more likely to use the Internet excessively, with some associations being stronger for boys than for girls. Prevention strategies focused on raising adolescent awareness of the risks and benefits of the Internet should target discriminated adolescents, especially boys, as they seem to be the vulnerable group

Cotton-Grass and Blueberry have Opposite Effect on Peat Characteristics and Nutrient Transformation in Peatland

Peatlands are large repositories of carbon (C). Sphagnum mosses play a key role in C sequestration, whereas the presence of vascular plants is generally thought to stimulate peat decomposition. Recent studies stress the importance of plant species for peat quality and soil microbial activity. Thus, learning about specific plant-microbe-soil relations and their potential feedbacks for C and nutrient cycling are important for a correct understanding of C sequestration in peatlands and its potential shift associated with vegetation change. We studied how the long-term presence of blueberry and cotton-grass, the main vascular dominants of spruce swamp forests, is reflected in the peat characteristics, soil microbial biomass and activities, and the possible implications of their spread for nutrient cycling and C storage in these systems. We showed that the potential effect of vascular plants on ecosystem functioning is species specific and need not necessarily result in increased organic matter decomposition. Although the presence of blueberry enhanced phosphorus availability, soil microbial biomass and the activities of C-acquiring enzymes, cotton-grass strongly depleted phosphorus and nitrogen from the peat. The harsh conditions and prevailing anoxia retarded the decomposition of cotton-grass litter and caused no significant enhancement in microbial biomass and exoenzymatic activity. Therefore, the spread of blueberry in peatlands may stimulate organic matter decomposition and negatively affect the C sequestration process, whereas the potential spread of cotton-grass would not likely change the functioning of peatlands as C sinks.Peer reviewe