732 research outputs found

    Real Costs Assessment of Solar-Hydrogen and Some Fossil Fuels by means of a Combustion Analysis

    Get PDF
    In order to compare solar-hydrogen and the most used fossil fuels, the evaluation of the "external" costs related to their use is required. These costs involve the environmental damage produced by the combustion reactions, the health problems caused by air pollution, the damage to land from fuel mining, and the environmental degradation linked to the global warming, the acid rains, and the water pollution. For each fuel, the global cost is determined as sum of the market price and of the correspondent external costs. In order to obtain a quantitative comparison, the quality of the different combustion reactions and the efficiency of the technologies employed in the specific application sector have to be considered adequately. At this purpose, an entropic index that considers the degree of irreversibility produced during the combustion process and the degradation of surroundings is introduced. Additionally, an environmental index that measures the pollutants released during the combustions is proposed. The combination of these indexes and the efficiency of the several technologies employed in four energy sectors have allowed the evaluation of the total costs, highlighting an economic scenario from which the real advantages concerning the exploitation of different energy carrier are determined

    A Second Law Analysis to Determine the Environmental Impact of Boilers Supplied by Different Fuels

    Get PDF
    A novel procedure to determine the environmental quality of boilers based on the combustion entropy degradation, the pollutants emission and the device efficiency is proposed. The entropy generation due to the chemical reaction was determined and then the irreversibilities on the external environment were first quantified. Successively, the entropy generation numbers of the combustion reactions were combined with the heat transfer process entropy generation of the boilers to consider the actual functioning conditions, in order to quantify the environmental damages by introducing an Environment Quality Index (EQI). A parametric study varying the heat exchanger efficiency, fluid flow rates and temperatures, for different fuel typologies, was performed to assess the environmental impact. Solar hydrogen was considered for its importance as future renewable energy carrier. The results showed that the highest EQI was produced by the natural gas, but if heat exchanger parameters are defined opportunely, the score gap with other fluids can be recovered. For hydrogen and coal decreasing the flue gases temperature or by increasing the flue gases mass flow rate can strongly improve the EQI index, whereas the gap recovery for Diesel is rather difficult

    Emerging Insect-Borne Diseases of Agricultural, Medical and Veterinary Importance

    Get PDF
    Current migrations, due to several causes, but mainly consequence of climate changes, are causing several problems in Southern Europe. Some migrations are evident and attract attention immediately; others are silent, but still important, like several ones involving agriculture and livestock. In the future, a number of products employed in pest control may lose their efficacy. Pesticide resistance should be considered an increasing problem, and more environmental-friendly control approaches against arthropod pests are urgently needed. Two examples from the South of Italy clearly explain the kind of arising alerts and the complex network involving abiotic and biotic causes. The first case is the growing number of blue-tongue disease outbreaks, vectored by Culicoides sp. The second case is the alarm concerning the olive trees epidemic disease in Apulia, due to the bacterium Xylella fastidiosa. The development of new pest control methods is required in order to minimize negative effects of currently marketed synthetic pesticides. In this scenario, natural product research can afford solutions as part of an integrated pest control system. Preliminary results concerning the use of neem, Azadirachta indica, in control of insect vectors are discussed

    Professor Philippe Rasoanaivo Unveiling the ethnopharmacological potential of the flora of Madagascar: in memory of Philippe Rasoanaivo

    Get PDF
    Professor Philippe Rasoanaivo, University of Antananarivo, Madagascar, died on Wednesday, 13 July 2016 from a heart attack, at the age of 70. Professor Rasoanaivo was well known as one of the most distinguished African phytochemists, as also recognised by several international prizes. He won the 2015 Olusegun Obasanjo Prize for using traditional medicine to improve the efficacy of existing drugs for brain disorders and also treating sexual dysfunction among men. He had just been awarded the Prize at the last General Assembly meeting in Kasane, Botswana, in June 2016. Professor Rasoanaivo authored several books and more than 150 international research articles, including some recently published in Natural Product Research. Professor Rasoanaivo developed a unique mixture of scientific knowledge dedicated to the utilisation of endemic plants for ethnobotanical, economic, medicinal and social uses. He wanted to learn everything that was necessary to understand and study the extraordinary flora of his country, obtaining this information to help its people. Throughout his life, countless examples of his remarkableness can easily be found. He was an excellent botanist and, living in a country well known for an exceptional endemic flora, he was able to find and collect many species, and show the world their importance. He was a great ethnopharmacologist, learning the popular uses of plants from the people of his country, and using this information to start a scientific validation of their efficacy. He was a modern researcher: in times of fragmented research, he was able to perform the full range of research on natural products, from chemistry to applied pharmacology. He was successful and organised director of the Institut Malgache de Recherches Appliquées, promoting the cultivation of crops of economic importance. In this obituary, we have provided a synthesis of his important scientific achievements and human qualities, since we had the privilege of working with him and he was able to teach us what modern ethnopharmacology is

    Real Costs Assessment of Solar-Hydrogen and Some Fossil Fuels by means of a Combustion Analysis

    Get PDF
    In order to compare solar-hydrogen and the most used fossil fuels, the evaluation of the “external” costs related to their use is required. These costs involve the environmental damage produced by the combustion reactions, the health problems caused by air pollution, the damage to land from fuel mining, and the environmental degradation linked to the global warming, the acid rains, and the water pollution. For each fuel, the global cost is determined as sum of the market price and of the correspondent external costs. In order to obtain a quantitative comparison, the quality of the different combustion reactions and the efficiency of the technologies employed in the specific application sector have to be considered adequately. At this purpose, an entropic index that considers the degree of irreversibility produced during the combustion process and the degradation of surroundings is introduced. Additionally, an environmental index that measures the pollutants released during the combustions is proposed. The combination of these indexes and the efficiency of the several technologies employed in four energy sectors have allowed the evaluation of the total costs, highlighting an economic scenario from which the real advantages concerning the exploitation of different energy carrier are determined

    Clinical epigenetics and restoring of metabolic health in severely obese patients undergoing batriatric and metabolic surgery

    Get PDF
    Epigenetic-sensitive mechanisms, mainly DNA methylation, mirror the relationship between environmental and genetic risk factors able to affect the sensitiveness to development of obesity and its comorbidities. Bariatric and metabolic surgery may reduce obesity-related cardiovascular risk through tissue-specific DNA methylation changes. Among the most robust results, differential promoter methylation of ACACA, CETP, CTGF, S100A8, and S100A9 genes correlated significantly with the levels of mRNA before and after gastric bypass surgery (RYGB) in obese women. Additionally, promoter hypermethylation of NFKB1 gene was significantly associated with reduced blood pressure in obese patients after RYGB suggesting useful non-invasive biomarkers. Of note, sperm-related DNA methylation signatures of genes regulating the central control of appetite, such as MC4R, BDNF, NPY, and CR1, and other genes including FTO, CHST8, and SH2B1 were different in obese patients as compared to non-obese subjects and patients who lost weight after RYGB surgery. Importantly, transgenerational studies provided relevant evidence of the potential effect of bariatric and metabolic surgery on DNA methylation. For example, peripheral blood biospecimens isolated from siblings born from obese mothers before bariatric surgery showed different methylation signatures in the insulin receptor and leptin signaling axis as compared to siblings born from post-obese mothers who underwent surgery. This evidence suggests that bariatric and metabolic surgery of mothers may affect the epigenetic profiles of the offspring with potential implication for primary prevention of severe obesity. We update on tissue-specific epigenetic signatures as potential mechanisms underlying the restoration of metabolic health after surgery suggesting useful predictive biomarkers

    Platelet Rich Plasma Enhancement of Skin Regeneration in an ex-vivo Human Experimental Model

    Get PDF
    An original ex vivo wounded skin culture protocol using autologous Platelet Rich Plasma (PRP) and enriched Dulbecco's Modified Eagle's Medium demonstrated a favourable modulation of the epithelial cells and fibroblasts proliferation, a relevant antiinflammatory action and a favourable modulation of the re-organization of collagen and elastic fibres. The step by step regenerative effects of PRP on human skin wound repair and regeneration process was observed over a period of 10 days

    Continued high prevalence of HIV, HBV and HCV among injecting and noninjecting drug users in Italy

    Get PDF
    We estimated the prevalence of HIV, HBV and HCV infections among injecting and non-injecting drug users treated within public drug-treatment centres in Italy to determine the correlates of infection. In the sample of 1330 drug users, the prevalence of HIV was 14.4% among drug injectors and 1.6% among non-injectors; the prevalence of HBV was 70.4% among injecting drug users and 22.8% among non-injectors and of HCV was 83.2% among injecting drug users and 22.0% among non-injectors. Old age, unemployment, and intravenous drug use were significantly correlated with each of the infections, as well as a longer history of injecting drug use. The results indicate that these infections continue to circulate among drug users, highlighting the need for monitoring of this group in Italy

    DNA barcoding and evolutionary lineage of 15 insect pests of horticultural crops in South India

    Get PDF
    Abstract Pest management tools should rely to proper identification of arthropod species, which are usually classified relying on morphological keys. However, the shortcomings and limitations of the conventional taxonomical identification methods highlighted need for new and simple methods of pest identification. In this research, DNA barcoding was used to identify 15 insect pests attacking horticultural crops in South India. Accurate phylogenetic information and evolutionary divergence data were supported and evidenced by various parameters, including the rates of substitution, nucleotide composition, genetic divergence, test of selection and saturation analysis. The null hypothesis of neutral selection was rejected in favour of the alternate hypothesis of purifying selection. NJ and ML trees were calculated and the individuals of the same species clustered together based on the CO1 sequence similarity, regardless of their collection site and geographic location. Overall, this study adds basic knowledge to molecular ecology of important insect pests attacking horticultural crops in South India

    Larvicidal and ovideterrent properties of neem oil and fractions against the filariasis vector Aedes albopictus (Diptera: Culicidae): a bioactivity survey across production sites

    Get PDF
    Neem seed oil (NSO) of Azadirachta indica (Meliaceae) contains more than 100 determined biologically active compounds, and many formulations deriving from them showed toxicity, antifeedancy and repellence against a number of arthropod pests. However, it is widely known that botanical products can differ in their chemical composition and bioactivity, as function of the production site and production process. We used high-performance thin layer chromatography (HPTLC) to investigate differences in chemical constituents of NSOs from three production sites. HPTLC analyses showed several differences in chemical abundance and diversity among NSOs, with special reference to limonoids. Furthermore, the three NSOs and their fractions of increasing polarities [i.e. ethyl acetate (EA) fraction and butanol (BU) fraction] were evaluated for larvicidal toxicity and field oviposition deterrence against the Asian tiger mosquito, Aedes albopictus, currently the most invasive mosquito worldwide. Results from bioactivity experiments showed good toxicity of NSOs and EA fractions against A. albopictus fourth instarlarvae (with LC50 values ranging from 142.28 to 209.73 ppm), while little toxicity was exerted by BU fractions. A significant effect of the production site and dosage was also found and is probably linked to differences in abundance of constituents among samples, as highlighted by HPTLC analyses. NSOs and EAs were also able to deter A. albopictus oviposition in the field (effective repellence values ranging from 98.55 to 70.10 %), while little effectiveness of BU fractions was found. Concerning ovideterrent activity, no difference due to the production site was found. This is the first report concerning larvicidal toxicity of NSO against A. albopictus and ovideterrence against Culicidae in the field. The chance to use chemicals fromthe NSO EA fraction seems promising, since they are effective at lower doses, if compared to synthetic products currently marketed, and could be an advantageous alternative to build newer and safer mosquito control tools
    • …
    corecore