How does serum brain natriuretic peptide level change under nasal continuous positive airway pressure in obstructive sleep apnea-hypopnea syndrome?

Background: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with cardiovascular morbidity and mortality, which can be improved by using continuous positive airway pressure (CPAP) therapy. However, the pathophysiological links between the two kinds of disease and the mechanism of the CPAP effect remain incompletely understood. We aimed to inquire into the myocardial involvement in this relationship. We suggested that serum brain natriuretic peptide (BNP) is sensitive enough to detect myocardial stress caused by OSAHS.Design and methods: Sixty-four subjects without cardiovascular disease (21 controls, 24 normotensive OSAHS patients, and 19 hypertensive OSAHS patients) were analyzed for serum BNP at baseline and serially over 6 months. CPAP was applied to 23 patients with severe OSAHS.Results: At baseline, the serum BNP levels were significantly higher (p0.0001) in the OSAHS group (22.3914.79 pg/ml) than in the control group (9.296.75 pg/ml). Increased serum BNP levels were significantly associated with mean transcutaneous oxygen saturation (SpO2) (pB0.0001), minimal SpO2 (p0.002), oxygen desaturation index (p0.001), and total sleep time spent with SpO2 lower than 90% (p0.002). All patients with elevated BNP levels (]37 pg/ml) had moderate or severe OSAHS (11/43 OSAHS patients). The more severe the OSAHS, the higher the BNP levels were. However, only the difference between severe and mild OSAHS was statistically significant (p0.029). Hypertensive OSAHS patients had the highest baseline BNP levels (27.7916.74 pg/ml). They were significantly higher (p0.001) than in normotensive OSAHS patients (18911.72 pg/ml) (p0.039) and the controls (9.296.75 pg/ml). As compared with baseline, treatment with CPAP significantly decreased BNP levels in both hypertensive and normotensive OSAHS patients (respectively, from 36916.10 to 29.7914.29 pg/ml, pB0.001, and from 20910.09 to 1698.98 pg/ml, pB0.001). In contrast, the BNP levels slightly increased in the controls (from 9.296.75 to 9.597.02 pg/ml, p0.029), but there was no statistically significant difference in comparison with the baseline value. The effect of CPAP on BNP levels was more marked in patients with higher baseline BNP levels and those with the most prolonged nocturnal desaturation (p0.001, r0.65). It was also more marked in hypertensive OSHAS patients (p0.015, r0.72) in comparison with normotensive OSAHS patients (p0.03, r0.62).Conclusion: BNP seems to be sensitive enough to detect myocardial stress caused by OSAHS. As such, it is a potential marker for screening of preclinical cardiovascular damage in patients with untreated OSAHS. Application of CPAP decreases levels significantly in normotensive and particularly in hypertensive OSAHS. These findings are consistent with previous results suggesting the potential benefits of CPAP on cardiovascular outcome in OSAHS patients.Keywords: sleep apnea; brain natriuretic peptide; positive airway pressure therapy; myocardial stress; hypertensio

Short and Long-Term Effect of Land Use and Management on Soil Organic Carbon Stock in Semi-Desert Areas of North Africa-Tunisia

Soil organic carbon (SOC) plays an important role in the global C cycle, as well as in the maintenance and improvement of the soil quality. Over time, special attention has been paid to it in the study of the SOC reserves worldwide; however, reduced attention has been given to assessing the spatial patterns of SOC stock (SOCS) in semi-desert ecosystems. In this line, there are no conclusive studies in drylands of Africa affected by aeolian processes (semi-desert conditions) mainly due to the complexity of sample collection, and this is especially significant in some soil types such as Arenosols (AR) and Calcisols (CL). This study evaluated the spatial variability of SOC and SOCS in AR and CL with woody crops in relation to land use and management (old plantations > 100 years: centenary olive grove; new plantations < 12 years: young olive grove, almond, and pistachio) in semi-desert conditions. For this purpose, 16 soil profiles (for 0–40 and 40–100 cm depth) were selected and studied in an experimental area of Menzel Chaker-Sfax in southeastern Tunisia (North Africa). The main results indicated that the SOCS on average was higher in Old Cultivated AR (OC-AR) with 41.16 Mg ha−1 compared to Newly Cultivated AR (NC-AR) with 25.13 Mg ha−1. However, the SOCS decreased after a long period of cultivation in CL from 43.00 Mg ha−1 (Newly Cultivated CL: NC-CL) to 32.19 Mg ha−1 (Old Cultivated CL: OC-CL). This indicates that in the long term, CL has more capacity to store SOC than AR, and that in the short term, AR is more sensitive to land management than CL

A global perspective on soil science education at third educational level; knowledge, practice, skills and challenges

The pivotal role of soil as a resource is not fully appreciated by the general public. Improving education in soil science represents a challenge in a world where soil resources are under serious threat. Today’s high school students, the world’s future landowners, agriculturalists, and decision makers, have the potential to change society’s apathy towards soils issues. This research aimed to compare the level of soil education in high and/or secondary schools in forty-three countries worldwide, together comprising 62% of the world's population. Comparisons were made between soil science content discussed in educationally appropriate textbooks via a newly proposed soil information coefficient (SIC). Interviews with teachers were undertaken to better understand how soil science education is implemented in the classroom. Statistical analyses were investigated using clustering. Results showed that gaps in soil science education were most commonly observed in countries where soil science is a non-compulsory or optional subject. Soil science concepts are predominantly a part of geography or environmental science curricula. Consequently, considerable variability in soil science education systems among investigated countries exists. Soil information coefficient‘s outcomes demonstrated that a methodological approach combining textbooks and the use of modern digitally based strategies in the educational process significantly improved soil education performances. Overall, soil science education is under-represented in schools worldwide. Dynamic new approaches are needed to improve pivotal issues such as: i) promoting collaborations and agreements between high school and universities; ii) encouraging workshops and practical exercises such as field activities; and, iii) implementing technology tools. This, in turn, will prepare the next generation to contribute meaningfully towards solving present and future soil problems

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Atomistic Descriptors for Machine Learning Models of Solubility Parameters for Small Molecules and Polymers

Descriptors derived from atomic structure and quantum chemical calculations for small molecules representing polymer repeat elements were evaluated for machine learning models to predict the Hildebrand solubility parameters of the corresponding polymers. Since reliable cohesive energy density data and solubility parameters for polymers are difficult to obtain, the experimental heat of vaporization &Delta;Hvap of a set of small molecules was used as a proxy property to evaluate the descriptors. Using the atomistic descriptors, the multilinear regression model showed good accuracy in predicting &Delta;Hvap of the small-molecule set, with a mean absolute error of 2.63 kJ/mol for training and 3.61 kJ/mol for cross-validation. Kernel ridge regression showed similar performance for the small-molecule training set but slightly worse accuracy for the prediction of &Delta;Hvap of molecules representing repeating polymer elements. The Hildebrand solubility parameters of the polymers derived from the atomistic descriptors of the repeating polymer elements showed good correlation with values from the CROW polymer database

Supplementary potassium and calcium improves salt tolerance in olive plants

10 Pags.- 3 Tabls.- 8 Figs.Soil salinization increase, aggravated by the foreseen low precipitation related to climate change, is a worldwide problem causing crop yield reductions, affecting population and environmental issues due to the salt-containing low-quality water. Enhancing the salt tolerance of plants, especially crops, is an interesting and effective solution to minimize salt-related crop problems. Toward this goal, we evaluated in this study the effect of potassium (K) and calcium (Ca) application on plant growth, nutrient uptake, water status and electrolyte and potassium leakage of two-year-old potted olive plants grown under saline conditions (100 and 200 mM NaCl). Results showed that all measured parameters were affected by salinity. However, the application of K and Ca enhanced the growth parameters, improved the water status and reduced the electrolyte and K leakage, the latter reflecting a positive effect in membrane integrity. The nutritional balance was moderately improved in salt-stressed plants treated with K and Ca. The significant reduction in sodium (Na) concentration in both leaves and roots, and the enhancement of K and Ca concentration in the different plant tissues indicated that the K and Ca supply raised the Na exclusion mechanism. The largest positive effect of K was observed with 40 mM KNO3 dose at both salinity levels. Furthermore, the beneficial effect of Ca was achieved with 40 and 10 mM CaCl2 in plants grown at 100 and 200 mM NaCl, respectively. Thus, for this relatively salt-tolerant and economically important crop, K and Ca are recommended to supply in order to mitigate the harmful effects of salinity and to develop saline agriculture in, for instance, coastal saline land.This work was supported by grants from Tunisian LPOI (LR16 IO 03-SERS-Tunisia) and International Plant Nutrition Institute (IPNI).Peer reviewe

Assessment of tolerance to NaCl salinity of five olive cultivars, based on growth characteristics and Na+ and Cl− exclusion mechanisms

10 Pags., 2 Tabls., 6 Figs.Changes caused by NaCl-induced salinity on several growth parameters and ions accumulation have been measured in five olive (Olea europaea L.) cultivars (‘Chemlali’, ‘Chetoui’, ‘Koroneiki’, ‘Arbequina I18’, and ‘Arbosana I43’) growing in a greenhouse in nutrient solution pot experiment. One-year-old plants were transplanted to sand–perlite (1:1) culture, and were irrigated with half-strength Hoagland nutrient solution containing NaCl at various levels (0.5, 50, 100 and 200 mM). Salinity induced significant decrease in growth parameters, but to a different extent in each cultivar. Leaf growth and total leaf area per plant were significantly affected by all salinity treatments in all studied cultivars, being ‘Arbequina I18’ the most sensitive cultivar. Leaf drop phenomenon was observed from 60 days after salt application at high salinity treatments, mainly in Arbequina I18. Contrary to leaf area, leaf thickness increased progressively during the experiment. ‘Chemlali’ developed thicker leaves at the two highest salinity treatments when compared to the other cultivars. Na+ and Cl− concentrations were higher in roots than in shoots and leaves in most of the cultivars investigated. The effectiveness of Na+ exclusion mechanism in the roots differed significantly among studied cultivars, working effectively in ‘Chemlali’ (by inhibiting translocation of Na+ to the aerial part) and being much less efficient in ‘Arbequina I18’. Furthermore, leaf abscission can be considered as an additional tolerance mechanism of olive cultivars allowing the elimination of leaves that had accumulated Na+ and Cl− ions. Tolerance to salinity stress was as follows: ‘Chemlali’ > ‘Chetoui’ > ‘Arbosana I43’ > ‘Koroneiki’ > ‘Arbequina I18’. This order of salt tolerance was indicated by lower reduction in plant growth parameters (shoot elongation, trunk diameter, total plant dry weight, internodes length, and total leaf area), the increase of leaf thickness, and by the effectiveness of the exclusion mechanism of Na+ and Cl− in the root system.This work was supported by grants from Olive tree Institute to Ajmi Larbi and Monji Msallem. Fermín Morales wishes to thank Gobierno de Aragón (A03 research group) for financial support.Peer reviewe

Effects of Olive Mill Wastewater on Soil Nutrients Availability

Abstract Olive mill wastewater (OMW) is one of complex wastewater generated by the olive oil extraction process. It is characterized by high values of COD, BOD and phytotoxic levels of polyphenols, but also by a high amount of organic compounds and plant mineral nutrients. Therefore, OMW field spreading may represent a low cost contribution to soil amendment. Olive mill wastewater (OMW) spraying effects onto soil physico-chemicals characteristics were investigated. Three OMW doses 50, 100 and 200 m 3 ha -1 year -1 were applied for ten successive years on sandy soil. The findings showed that the pH of the soil, electrical conductivity and organic matter, total nitrogen, phosphorus, sodium, and potassium soil contents increased with increased OMW supply. While, no variations were recorded in calcium and magnesium on soil contents

Carbon and nitrogen balances and CO2 emission after exogenous organic matter application in arid soil

Addition of organic amendments (OAs) could be a means to sequester carbon (C) in soils. However, the efficiency of C sequestration depends on how OAs evolve in the soil. A field study was installed in arid soil to which was added one of five OAs – olive husk-based compost (CM), palm leaf-based compost (CP), crushed olive pruning (GW), fresh olive mill wastewater (OMW) or fermented ovine manure (OM) – at an equivalent fixed level of 350 g of C/m2. C and N mineralization were followed for 112 days by measuring the evolution of released CO2 and mineral N evolution. The results showed that CM and CP did not disturb soil respiration, with a very low CO2 emission or almost no respiration for the CM, while CO2 release reached 7.6 g of CO2/m2 for GW and OMW. Soil organic carbon (SOC) was sustainably improved by 0.54% and 0.50%, respectively, for CM and CP. N mineralization showed no significant difference between amended and untreated soils. Based on these results, compost amendment was the most efficient for C sequestration to enhance soil fertility and consequently reduce the rate of CO2 emission

Assessment of Cholesterol, Glycemia Control and Short- and Long-Term Antihypertensive Effects of Smooth Hound Viscera Peptides in High-Salt and Fructose Diet-Fed Wistar Rats

In this study, the antihypertensive activity of Purafect®-smooth hound viscera protein hydrolysate (VPH) and its peptide fraction with molecular weight (MW) below 1 kDa (VPH-I) was investigated. In addition, the lipase inhibitory activity, as well the anticoagulant potential, in vitro, were assessed. The antihypertensive effects of VPH and VPH-I were studied during 24 h (short-term effect) and 30 days (long-term effect) using high-salt (18% NaCl) and -fructose (10%) diet (HSFD)-induced hypertension. Data showed that, 4 h post-administration of VPH and VPH-I (200 mg/kg BW), the systolic blood pressure of rats was reduced by about 6 and 9 mmHg, respectively. These effects were similar to that obtained with Captopril (~9 mmHg at t = 4 h). On the other hand, exposing the rats to daily to HSFD, coupled to the administration of viscera peptides, was found to attenuate hypertension. In addition, the proteins’ treatments were able to correct lipid and glycemic disorders, by reducing the total cholesterol and triglyceride contents and resorting to the plasma glucose level, compared to the HSFD group. Overall, the present findings demonstrated the preventive effect of VPH-peptides from hypertension complications, as a result of their biological properties.This research was funded by the Ministry of Higher Education and Scientific Research, TunisiaWe acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI