Institution
University of Sfax
Education•Sfax, Tunisia•
About: University of Sfax is a education organization based out in Sfax, Tunisia. It is known for research contribution in the topics: Dielectric & Crystal structure. The organization has 7940 authors who have published 13938 publications receiving 155864 citations. The organization is also known as: US.
Papers published on a yearly basis
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TL;DR: Several selected pharmaceutical and biomedical applications are presented, in which chitin and chitosan are recognized as new biomaterials taking advantage of their biocompatibility and biodegradability.
Abstract: This review describes the most common methods for recovery of chitin from marine organisms. In depth, both enzymatic and chemical treatments for the step of deproteinization are compared, as well as different conditions for demineralization. The conditions of chitosan preparation are also discussed, since they significantly impact the synthesis of chitosan with varying degree of acetylation (DA) and molecular weight (MW). In addition, the main characterization techniques applied for chitin and chitosan are recalled, pointing out the role of their solubility in relation with the chemical structure (mainly the acetyl group distribution along the backbone). Biological activities are also presented, such as: antibacterial, antifungal, antitumor and antioxidant. Interestingly, the relationship between chemical structure and biological activity is demonstrated for chitosan molecules with different DA and MW and homogeneous distribution of acetyl groups for the first time. In the end, several selected pharmaceutical and biomedical applications are presented, in which chitin and chitosan are recognized as new biomaterials taking advantage of their biocompatibility and biodegradability.
1,554 citations
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University of Sfax1, University of Münster2, Otto-von-Guericke University Magdeburg3, German Center for Neurodegenerative Diseases4, University of Gafsa5, Rio de Janeiro State University6, University of Twente7, Catholic University of the Sacred Heart8, Estácio S.A.9, American University in the Emirates10, Imam Khomeini International University11, University of Paris12, University of Genoa13, University of Arkansas14, Stanford University15, University of Toulouse16, Assiut University17, Karlsruhe Institute of Technology18, Georgia Southern University19, Government of Extremadura20, University Medical Center Groningen21, University of Ulm22, Yarmouk University23, University of Jordan24, University of Porto25, Loughborough University26, Paris West University Nanterre La Défense27
TL;DR: Results indicate that isolation is a necessary measure to protect public health, but results indicate that it alters physical activity and eating behaviours in a health compromising direction.
Abstract: Background: Public health recommendations and governmental measures during the COVID-19 pandemic have resulted in numerous restrictions on daily living including social distancing, isolation and home confinement. While these measures are imperative to abate the spreading of COVID-19, the impact of these restrictions on health behaviours and lifestyles at home is undefined. Therefore, an international online survey was launched in April 2020, in seven languages, to elucidate the behavioural and lifestyle consequences of COVID-19 restrictions. This report presents the results from the first thousand responders on physical activity (PA) and nutrition behaviours. Methods: Following a structured review of the literature, the “Effects of home Confinement on multiple Lifestyle Behaviours during the COVID-19 outbreak (ECLB-COVID19)” Electronic survey was designed by a steering group of multidisciplinary scientists and academics. The survey was uploaded and shared on the Google online survey platform. Thirty-five research organisations from Europe, North-Africa, Western Asia and the Americas promoted the survey in English, German, French, Arabic, Spanish, Portuguese and Slovenian languages. Questions were presented in a differential format, with questions related to responses “before” and “during” confinement conditions. Results: 1047 replies (54% women) from Asia (36%), Africa (40%), Europe (21%) and other (3%) were included in the analysis. The COVID-19 home confinement had a negative effect on all PA intensity levels (vigorous, moderate, walking and overall). Additionally, daily sitting time increased from 5 to 8 h per day. Food consumption and meal patterns (the type of food, eating out of control, snacks between meals, number of main meals) were more unhealthy during confinement, with only alcohol binge drinking decreasing significantly. Conclusion: While isolation is a necessary measure to protect public health, results indicate that it alters physical activity and eating behaviours in a health compromising direction. A more detailed analysis of survey data will allow for a segregation of these responses in different age groups, countries and other subgroups, which will help develop interventions to mitigate the negative lifestyle behaviours that have manifested during the COVID-19 confinement.
1,275 citations
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King Juan Carlos University1, University of Vermont2, Pablo de Olavide University3, Technical University of Madrid4, Northern Arizona University5, University of La Serena6, Instituto Potosino de Investigación Científica y Tecnológica7, Universidad Simón Rodríguez8, Ben-Gurion University of the Negev9, State University of Feira de Santana10, Universidad Técnica Particular de Loja11, University of Sfax12, University of New South Wales13, Central University of Venezuela14, National University of San Juan15, University of the Bío Bío16, Virginia Tech College of Natural Resources and Environment17, Ohio State University18, National Agrarian University19, National University of La Pampa20, University of New England (Australia)21, Office of Environment and Heritage22, Spanish National Research Council23, Northeast Normal University24, Agricultural Research Organization, Volcani Center25
TL;DR: A global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth’s land surface and support over 38% of the human population, suggests that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in dryland.
Abstract: Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth’s land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.
941 citations
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Pablo de Olavide University1, King Juan Carlos University2, Northern Arizona University3, Colorado State University4, University of Córdoba (Spain)5, Instituto Potosino de Investigación Científica y Tecnológica6, University of La Serena7, University of Jaén8, University of Sfax9, State University of Feira de Santana10, University of New South Wales11, Universidad Técnica Particular de Loja12, National University of San Juan13, University of the Bío Bío14, Central University of Venezuela15, National University of La Pampa16, Virginia Tech College of Natural Resources and Environment17, Northeast Normal University18, Ohio State University19, Université du Québec à Montréal20, International Potato Center21, University of New England (Australia)22, Universidad Centroccidental Lisandro Alvarado23, Agricultural Research Organization, Volcani Center24, Office of Environment and Heritage25
TL;DR: Any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P, suggesting the provision of key services provided by these ecosystems could be negatively affected.
Abstract: The biogeochemical cycles of carbon (C), nitrogen (N) and phosphorus (P) are interlinked by primary production, respiration and decomposition in terrestrial ecosystems. It has been suggested that the C, N and P cycles could become uncoupled under rapid climate change because of the different degrees of control exerted on the supply of these elements by biological and geochemical processes. Climatic controls on biogeochemical cycles are particularly relevant in arid, semi-arid and dry sub-humid ecosystems (drylands) because their biological activity is mainly driven by water availability. The increase in aridity predicted for the twenty-first century in many drylands worldwide may therefore threaten the balance between these cycles, differentially affecting the availability of essential nutrients. Here we evaluate how aridity affects the balance between C, N and P in soils collected from 224 dryland sites from all continents except Antarctica. We find a negative effect of aridity on the concentration of soil organic C and total N, but a positive effect on the concentration of inorganic P. Aridity is negatively related to plant cover, which may favour the dominance of physical processes such as rock weathering, a major source of P to ecosystems, over biological processes that provide more C and N, such as litter decomposition. Our findings suggest that any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P. These changes would uncouple the C, N and P cycles in drylands and could negatively affect the provision of key services provided by these ecosystems.
667 citations
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TL;DR: In this article, the authors examined the nexus between CO 2 emissions, energy consumption and economic growth using simultaneous-equations models with panel data of 14 MENA countries over the period 1990-2011.
615 citations
Authors
Showing all 8071 results
Name | H-index | Papers | Citations |
---|---|---|---|
Francisco Herrera | 139 | 1001 | 82976 |
Alessandro Gandini | 67 | 348 | 19813 |
Sami Sayadi | 65 | 386 | 13709 |
Carlo Foresta | 64 | 433 | 15807 |
Moncef Nasri | 58 | 375 | 12775 |
George Aggelis | 56 | 145 | 10885 |
Sami Boufi | 51 | 184 | 8734 |
Pere Mutjé | 47 | 197 | 6209 |
Hamadi Attia | 46 | 227 | 7642 |
Mohamed Bouaziz | 43 | 194 | 5300 |
Youssef Gargouri | 42 | 199 | 5557 |
Tomás Caraballo | 41 | 261 | 5489 |
Adel M. Alimi | 40 | 716 | 9168 |
Ahmed Rebai | 39 | 258 | 4947 |
Gilles André | 38 | 328 | 5805 |