8 research outputs found
Overlapping Signal Separation Method Using Superresolution Technique Based on Experimental Echo Shape
الحياة الاجتماعية في عيلام في الألف الثالث والثاني ق.م
من خلال الاطلاع على التاريخ الحضاري لمنطقة غربي آسيا القديمة بشكل عام ومنطقة الهضبة الإيرانية وعلاقتها مع منطقة بلاد الرافدين يمكن الحصول على بعض المعلومات عن الإنسان القديم الذي سكن عيلام.
توضح لنا دراسة الحياة الاجتماعية في عيلام ومقارنتها مع الحياة الاجتماعية لسكان بلاد الرافدين طبيعة المجتمع العيلامي تركيبته العرقية وثقافته واتصاله الحضاري بغيره من الشعوب القديمة في العالم القديم، في الألف الثالث قبل الميلاد، الأمر الذي انعكس على حياة الإنسان العيلامي في مختلف جوانب الحياة
Vegetation dynamics and regeneration of Pinus pinea forests in Mount Lebanon: Towards the progressive disappearance of pine
International audiencePinus pinea is a species of great economic and ecological importance in Lebanon, but there is a lack of knowledge about the distribution of the pine forests, their vegetation dynamics and regeneration. Our study aims to produce the first classification of the pine stands according to their floristic composition and the abiotic factors of the Mount Lebanon region and to analyse natural pine recruitment. Floristic composition, environmental and soil factors as well as stand dendrometric characteristics and woody seedling regeneration were recorded on fifty plots distributed in the main stone pine stands of the study area. Using canonical correspondence and clustering analyses, we classified pine stands into five groups which were mainly influenced by physiographic factors (altitude, slope, temperature, rainfall), nature of the bedrock, and evidence of human interventions. Most stone pine stands in Mount Lebanon were dense (849 stems.ha−1), old (81 years) with a high basal area (49 m2.ha−1). Pine regeneration was particularly scant, and the understory was dominated by the oak species: Quercus calliprinos, mainly and Quercus infectoria, secondarily. Based on these results, we concluded that the presence of stone pine and its persistence are linked to human actions. In the absence of human intervention, the stone pine stands will progressively disappear and be replaced by oak formations. Thus, an urgent management plan is required to favour pine regeneration to allow for the renewal of the pine stands in the Mount-Lebanon region
Soil scarification favors natural regeneration of Pinus pinea in Lebanon forests: Evidences from field and laboratory experiments
International audiencePinus pinea is an important species for ecological and economic reasons in the Mediterranean area and especially in Lebanon. However, conditions of its natural regeneration have received little attention. Our study aimed to test the influence of soil disturbances, predation and autotoxicity on pine regeneration. A seed sowing field experiment was conducted in a mature stand in which two types of soil disturbances were tested (soil scarification and litter burning) in presence or absence of predation. In addition, a laboratory experiment evaluating the influence of litter (present, absent or burned) and green needle leachates (i.e. in order to mimic potential autotoxicity) on seed germination and seedling growth was conducted. Results showed a strong effect of soil disturbance, in particular soil scarification which promoted seedling emergence and early survival, whereas the role of predation was low. Forty to sixty days after seed installation, seedling density peaked at 14.9 ± 0.4 seedling.m in the scarification treatment, 13.1 ± 0.4 in the burning treatment and 8.4 ± 0.4 in the control treatment. However, an unexpected high mortality rate was recorded at the end of the field experiment in all treatments, as after seven months seedling density dropped to 0.2 ± 0.02. In the laboratory experiment, we emphasized an autotoxic effect of green needle aqueous extract on seed germination and seedling growth in the presence of litter. This allelopathic effect could be potentially linked to the presence of quinic acid which was measured as the major metabolite detected in needle aqueous extracts. In conclusion, we recommend soil preparation treatments to favour seedling emergence in combination with thinning to achieve seedling development on the long term
Phytochemical and pharmacological properties of essential oils from Cedrus species
Natural products frequently exert pharmacological activities. The present review gives an overview of the ethnobotany, phytochemistry and pharmacology of the Cedrus genus, e.g. cytotoxic, spasmolytic immunomodulatory, antiallergic, anti-inflammatory and analgesic activities. Cancer patients frequently seek remedies from traditional medicinal plants that are believed to exert less side effects than conventional therapy with synthetic drugs. A long-lasting goal of anti-cancer and anti-microbial therapy research is to find compounds with reduced side effects compared to currently approved drugs. In this respect, Cedrus species might be of interest. The essential oil isolated from Cedrus libani leaves may bear potential for drug development due to its high concentrations of germacrene D and β-caryophyllene. The essential oils from Cedrus species also show bioactivity against bacteria and viruses. More preclinical analyses (e.g. in vivo experiments) as well as clinical trials are required to evaluate the potential of essential oils from Cedrus species for drug development
Hydrocarbon potential and porosity types of the Geli Khana Formation (Middle Triassic), Northern Iraq
SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study
Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling.
Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty.
Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year.
Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population