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Showing papers in "Natural Science in 2013"


Journal ArticleDOI
TL;DR: In this paper, the authors discussed the main causes in the development of sand and dust storms, in Iraq, and the most effective reasons are the haphazard driving and military operations, especially in the Iraqi Southern Desert.
Abstract: Iraq is one of the most affected countries in the Middle East concerning the occurrences of sand and dust storms. The frequency of the occurrence has increased drastically in the last decade and it is increasing continuously. The events of sand and dust storms are either regional or local. The former, however, is more frequent than the latter. The regional event, generally extends outside the Iraqi territory, into different directions, but usually covers part of Syria, crossing the Iraqi territory towards Kuwait and Saudi Arabia, and/or towards the Arabian Gulf, and less frequently extends to Iran. The main causes in the development of sand and dust storms, in Iraq are discussed. The causes are also either regional or local. The former, however, causes more economic losses and harsh effect on the human’s health, as compared with the latter. One of the main reasons behind the development of sand and dust storms is the climatic changes within the region, especially the drastic decrease in the annual rate of rain fall, besides environmental changes, such as drying of the marshes, land degradation, and desertification. From the local causes, the most effective reason is the haphazard driving and military operations, especially in the Iraqi Southern Desert. Prudent management of water resources by using non-conventional resources and adapting suitable irrigation methods can greatly help to overcome this phenomenon and minimize the number of dust storm.

135 citations


Journal ArticleDOI
TL;DR: Results suggest that the essential oil from T. vulgaris L. and R. officinalis L. have potential to be used as a natural cytotoxic, antioxidant and antimicrobial agent in food processing.
Abstract: The essential oil composition of Thymus vulgaris L. and Rosmarinus officinalis L. endemic to France were determined by GC and GC-MS. Oils were assessed for their cytotoxic, antioxidant and antimicrobial activity. 31 and 37 different compounds were identified representing 99.64% and 99.38% of the thyme and rosemary oils respectively, where oxygenated monoterpenes constituted the main chemical class. Thymol (41.33%) and 1.8-cineole (24.10%) were identified as the main constituents of T. vulgaris L. and R. officinalis L., respectively. Essential oils (EOs) of selected plant species were evaluated for their in vitro cytotoxicity against the human lung adenocarcinoma epithelial cell line (A549). Cytotoxicity was measured using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphynyltetra-zolium bromide] colorimetric assay. Dose-dependent studies revealed IC50 of 8.50 ± 0.01 μg/mL and 10.50 ± 0.01 μg/mL after 72 h on the A549 cells for R. officinalis L. and T. vulgaris L., respectively. Antioxidant activity was determined using a quantitative DPPH (1,1-diphenyl- 2-picryl hydrazyl) assay. Thymus and rosemary EOs exhibited effective radical scavenging capacity with 50% inhibitory concentration (IC50) of 437 ± 5.46 μg/mL and 189 ± 2.38 μg/mL respectively and therefore acts as a natural antioxidant agent. The antimicrobial activity of these species has also been studied against several foodborne pathogens and food isolated Salmonella spp. including S. enteritidis of significant importance. According to the results, T. vulgaris L. showed higher bactericidal effect than those from R. officinalis L. These results suggest that the essential oil from T. vulgaris L. and R. officinalis L. have potential to be used as a natural cytotoxic, antioxidant and antimicrobial agent in food processing.

78 citations


Journal ArticleDOI
TL;DR: In this paper, a review summarizes mechanism, operation and latest potential applications of ultrasound in the food preservation, including low power ultrasound is thought to be an attractive nonthermal method due to overcome problems which occur during heat treatments such as physical and chemical changes, nutritional loss and change in organoleptic properties.
Abstract: Ultrasound is versatile and innovative technology due to its wide range of application and increase in knowledge and research studies. It is used in food industry for many purposes including analysis methods and food processings such as freezing, cutting, drying, tempering, homogenization, degassing, antifoaming, filtration and extraction. Ultrasound can be used as a promoter or alternative to food processing. There may be numereous advantages of using ultrasound for food processing such as effective mixing, increased mass transfer, reduced energy, reduced temperature and increased production rate. Due to the elimination of microorganisms and enzymes without destroying nutrients of foods, ultrasound can be used as an alternative method to thermal treatments in the food preservation. Additionally, low power ultrasound is thought to be an attractive nonthermal method due to overcome problems which occur during heat treatments such as physical and chemical changes, nutritional loss and change in organoleptic properties. This review summarizes mechanism, operation and latest potential applications of ultrasound in the food preservation.

64 citations


Journal ArticleDOI
TL;DR: A review of the existing literature data on PSW gasification, both as the result of laboratory and pilot-scale research, is presented in this article, with values of the activation energy in the order of 187 to 289 kJ/mol as a function of the PSW.
Abstract: The disposal of plastic solid waste (PSW) has become a major worldwide environmental problem. New sustainable processes have emerged, i.e. either advanced mechanical recycling of PSW as virgin or second grade plastic feedstock, or thermal treatments to recycle the waste as virgin monomer, as synthetic fuel gas, or as heat source (incineration with energy recovery). These processes avoid land filling, where the non-biodegradable plastics remain a lasting environmental burden. Within the thermal treatments, gasification and pyrolysis gain increased interest. Gasification has been widely studied and applied for biomass and coal, with results reported and published in literature. The application to the treatment of PSW is less documented. Gasification is commonly operated at high temperatures (> 600℃ to 800℃) in an air-lean environment (or oxygen-deficient in some applications): the air factor is generally between 20% and 40% of the amount of air needed for the combustion of the PSW. Gasification produces mostly a gas phase and a solid residue (char and ashes). The use of air introduces N2 in the product gases, thus considerably reducing the calorific value of the syngas, because of the dilution. The paper will review the existing literature data on PSW gasification, both as the result of laboratory and pilot-scale research. Processes developed in the past will be illustrated. Recently, the use of a sequential gasification and combustion system (at very high temperatures) has been applied to various plastic-containing wastes, with atmospheric emissions shown to be invariably below the legal limits. Operating results and conditions will be reviewed in the paper, and completed with recent own lab-scale experimental results. These results demonstrate that gasification of PSW can be considered as a first order reaction, with values of the activation energy in the order of 187 to 289 kJ/mol as a function of the PSW nature.

63 citations


Journal ArticleDOI
TL;DR: Among tested algae, Brown algae namely Cystoseira crinite exhibited the highest antibacterial activity among tested algal species.
Abstract: Marine macroalgae are considered as an excellent source of bioactive compounds which has a broad range of biological activities including antibacterial and antioxidant. Crude methanolic and water extracts of 19 marine algal species (6 Chlorophyta, 8 Phaeophyta and 5 Rhodophyta) collected from the western coast of Libya were evaluated for antibacterial activity against pathogenic bacteria (4 Gram-positive, 4 Gram-nega- tive). The extracts showed a significant antibacterial activity against Gram positive (Staphylococcus aureus, Bacillus subtilis, Bacillus spp., and Staphylococcus epidermidis) as well as Gram negative bacteria (Escherichia coli, Salmonella typhi, Klebsiella spp., and Pseudomonas aerugi- nosa). The algal aqueous and methanolic extracts displayed different degrees of antimicrobial activities against different bacteria, in some cases methanolic extracts showed higher antibacterial activity than aqueous extracts. Among tested algae, Brown algae namely Cystoseira crinite exhibited the highest antibacterial activity among tested algal species.

56 citations


Journal ArticleDOI
TL;DR: Improved understanding of the adaptation of beef cattle to their production environments is important, but adaptation is complex and thus difficult to measure, Fortunately, several proxy-indicators for adaptation such as reproductive, production and health traits are available.
Abstract: Developing countries from the southern hemisphere will be confronted by the same beef production challenges caused by global warming, because these countries are at the same geographical positions in southern latitudes. Global warming is expected to have a more extreme effect on the southern hemisphere than on other continents and will have a negative effect on the beef production environments in these countries. The negative effects will include high ambient temperatures, nutritional stress and altered patterns of animal diseases. Heat stress in beef cattle on veld/savannah is expected to increase as a result of changing weather patterns on a global and regional scale. This may negatively influence food production from beef cattle for the human food chain. Negative effects of increased temperatures and thus heat stress can include lower reproductive rates and weaning weights. The effect of heat stress can be partly addressed by nutritional strategies, such as replacing rapid fermentable carbohydrates with saturated fatty acids and the feeding of more by-pass protein and dietary electrolytes. Global warming will also alter the distribution pattern of animal diseases and the vectors of some of these diseases. This may even include the spread to South American countries. Likewise the nutritional value of natural pastures may be influenced. The effect of global warming on the quality of pastures will depend on whether the global warming is a result of increased carbon dioxide levels or not. An improved understanding of the adaptation of beef cattle to their production environments is important, but adaptation is complex and thus difficult to measure. Fortunately, several proxy-indicators for adaptation such as reproductive, production and health traits are available. The selection of animals and genotypes that are better adapted to the production system, including heat stress, is possible and should be persuade to ensure sustainable beef production in hotter climates.

56 citations


Journal ArticleDOI
TL;DR: In this article, the use of AM fungi for phytoremediation of toxic heavy metals has been discussed, where the authors focus on the role of mycorrhizal fungi in phytostabilization of toxic metals.
Abstract: Plants have a system of antioxidant enzymes, which helps to alleviate the effects of various types of stresses. Heavy metals like Cadmium and lead are tolerable for plants to certain extent. The antioxidant enzymes do not function properly at higher concentrations of Cadmium, lead and some other heavy metals. The activities of antioxidant enzymes are reduced due to reactive oxygen species produced as a result of heavy metal stress. The catalase activity was directly inhibited by O2- (Kono and Fridovich, 1982). These ROS are O2-, H2O2, and -OH which can react with many other biomolecules. Several metallic ions are produced by radical displacement reactions. These metallic ions inhibit the activity of antioxidant enzymes. Hence, enzymic antioxidant defense system of plants is affected and adversely inhibits plant growth and productivity. Mycorrhizal fungi are important in phytostabilization of toxic heavy metals. Plants having mycorrhizal association accumulate metallic pollutants by storing these heavy metals in Vesicles as well as in fungal hyphae in their roots, hence these metallic pollutants are immobilized and do not inhibit the growth and uptake of phosphorus and some other micronutrients. Mycorrhizal fungi also release various organic acids which increase the solubilisation of insoluble phosphate compounds present in soil. The unavailable forms of phosphorus are converted into available forms as a result of organic acids produced by fungi. AM fungi release glomalins that are certain metal sorble glycoproteins which increase the immobilization of toxic metals. Another protein is metallothionine released by certain AM fungi, which also reduces the heavy metal toxicity in soil. Mycorrhizal fungi also induce resistance in plants against pathogens, drought and salinity stress. Investigation on heavy metal stress resistant genes in mycorrhizal plants can be very helpful for phytoremediation. This review focuses on the use of AM fungi for phytoremediation.

55 citations


Journal ArticleDOI
TL;DR: Marmots cope with seasonality by hibernating as discussed by the authors, which increases the efficiency of fat accumulation and its use as the sole energy source during hibernation; however, prolonged vernal snow cover reduces reproduction and increases mortality.
Abstract: Conservation of marmots, large ground-dwelling squirrels restricted to the northern hemisphere, was impacted by direct human activity through hunting or modifying ecosystem dynamics. Regulating human activities reduced the threat of extinction. Climate change, an indirect human impact, threatens marmot survival through global warming and extreme weather events. Most marmot species occupy a harsh environment characterized by a short growing season and a long, cold season without food. Marmots cope with seasonality by hibernating. Their large size increases the efficiency of fat accumulation and its use as the sole energy source during hibernation. Marmot physiology is highly adapted to coping with low environmental temperatures; they are stressed by high heat loads. Global warming since the last ice age reduced the geographic distribution of some of the 15 species of marmots. Recent warming resulted in a movement upslope of their lower elevation boundary. This process likely will continue because warming is associated with drier unpalatable vegetation. Drought reduces reproduction and increases mortality; thus decreased summer rainfall in the montane environments where marmots live may cause local extinction. Snow cover, a major environmental factor, is essential to insulate hibernation burrows from low, stressful temperatures. However, prolonged vernal snow cover reduces reproduction and increases mortality. Montane areas currently lacking marmot populations because vernal snow cover persists beyond the time that marmots must begin foraging may become colonized if warming causes earlier snow melt. This benefit will be short-lived because decreased precipitation likely will result in unpalatable vegetation. Although some marmot populations are physiologically adapted to a warmer climate, global warming will increase too rapidly for any significant evolutionary response to dryness. The species that live in high, alpine meadows where tree and shrub invasions occur are most threatened with extinction. Captive breeding can preserve marmot species in the shortrun, but is impractical over the long-term. Widespread species are unlikely to be endangered in the foreseeable future, but local, low elevation populations will be lost.

44 citations


Journal ArticleDOI
TL;DR: Low power of ultrasound is a powerful analytical technique to investigate on physico-chemical properties of both biological and non-biological materials while at sufficiently high power, it generates shear forces that are able to create different effects.
Abstract: Mechanisms for interactions between ultrasound waves and materials vary as a function of input power of ultrasound The objectives of this study were to compare mode of actions for ultrasound waves at different input powers This study also describes various effects of ultrasound on materials at different input powers with emphasize on food and polymer applications At low power of ultrasound, the major mechanism is acoustic streaming and at a power above threshold value, the most possible one is acoustic cavitation Low power of ultrasound is a powerful analytical technique to investigate on physico-chemical properties of both biological and non-biological materials While at sufficiently high power, it generates shear forces that are able to create different effects For each pair of medium-acoustic wave, two types of mechanisms, acoustic streaming and cavitation may be occurred simultaneously

36 citations


Journal ArticleDOI
TL;DR: The microalgae studies showed a composition of amino acids that meet the nutritional requirements recommended by the FAO g·100 g-1 (FAO/WHO/UN, 1985) for adults and children (2 - 5 years), indicating that these proteins can be used in foods.
Abstract: This study evaluates the growth and chemical composition of the following marine microalgae: Dunaliella tertiolecta, Isochrysis galbana, and Tetraselmis gracilis and the chemical composition of Chlorella pyrenoidosa. Microalgae can produce a number of compounds of high commercial value for the industry, mainly for the food industry. The growth kinetics, cell volume, pigments, carbohydrates, proteins, lipids, and fatty acid and amino acid composition were evaluated. I. galbana had the largest number of cells per mL-1 (107), concentration of carotenoids (6.33 μg·mL-1), and carbohydrates (34.32%). D. tertiolecta and T. gracilis had the highest cell volume (560.6 and 592.7 μm3, respectively), the highest amount of total dry biomass. D. tertiolecta had the highest chlorophyll concentration (9.05 μg·mL-1), and C. pyrenoidosa had the highest protein (48.16%) and lipid (14.30%) content. The marine species D. Tertiolecta, I. galbana, and T. gracilis had high levels of monounsaturated fatty acids (C18:1 n9), and C. pyrenoidosa was high in polyunsaturated fatty acids (C18:2 n6 and C18:3 n3), indicating the present high nutritional value fatty acids. The microalgae studies showed a composition of amino acids that meet the nutritional requirements recommended by the FAO g·100 g-1 (FAO/WHO/UN, 1985) for adults and children (2 - 5 years), indicating that these proteins can be used in foods.

34 citations


Journal ArticleDOI
TL;DR: The in vivo degradation results suggested that the degradation rate of the CaCl2-derived scaffolds was better matched to dermis regeneration, indicating that the degraded rate of silk fibroin can be effectively regulated by changing the MW to achieve a suitable dermal tissue regeneration rate.
Abstract: Establishing an appropriate degradation rate is critical for tissue engineering scaffolds. In this study, the degradation rate of silk fibroin three-dimensional scaffolds was regulated by changing the molecular weight (MW) of the silk fibroin. The solubility of silk fibroin depends primarily on the ionic ability of the slovent to dissolve silk fibroin, therefore, we regulated the MW of the silk fibroin using LiBr, Ca(NO3)2 and CaCl2 to dissolve the silk fibers. SDS-PAGE analysis showed that the MW of the CaCl2-derived silk fibroin was lower than the MW produced using LiBr and Ca(NO3)2. In vitro and in vivo degradation results showed that the scaffolds prepared by low-MW silk fibroin were more rapidly degraded. Furthermore, FTIR and amino acid analysis suggested that the amorphous regions were preferentially degraded by Collagenase IA, while the SDS-PAGE and amino acid analysis indicated that the scaffolds were degraded into polypeptides (mainly at 10-30 kDa) and amino acids. Because the CaCl2-derived scaffolds contained abundant low MW polypeptides, inter-intramolecular entanglement and traversing of molecular chains in the crystallites reduced, which resulted in rapid degradation. The in vivo degradation results suggested that the degradation rate of the CaCl2-derived scaffolds was better matched to dermis regeneration, indicating that the degradation rate of silk fibroin can be effectively regulated by changing the MW to achieve a suitable dermal tissue regeneration rate.

Journal ArticleDOI
TL;DR: The results indicated that increasing concentrations of the studied HMs in seedlings tissues significantly reduced the seedlings growth, and Cd was more toxic to P. oleracea seedling, compared to Pb and Zn.
Abstract: We aimed to find the toxicological impacts of Cd, Pb and Zn in single dozes and in combinations on Purslane (Portulaca oleracea) seedling. The Pursolane seedlings grown in pots in a green house were treated with different soil treatments spiked (mg/kg) with Pb (300, 400 and 500), Cd (0.5, 1 and 1.5), and Zn (250, 500, 700) alone and then in specified combinations/concentrations i.e., Cd/Pb (0.5/300, 1/400, 1.5/500), Cd/Zn (0.5/250, 1/500, 1.5/700) and Pb/Zn (300/250, 400/500, 500/ 700). The results indicated that increasing concentrations of the studied HMs in seedlings tissues significantly (p < 0.05) reduced the seedlings growth. Cd was more toxic to P. oleracea seedling, compared to Pb and Zn. Roots of P. oleracea seedlings were more sensitive to the studied HMs in comparison with shoot. The uptake patterns showed antagonistic impacts on each other and were reflected in response to growth parameters. The combine toxicities of Cd, Pb and Zn (Cd/Pb, Cd/Zn and Pb/Zn) were more than the toxicity due to single dose of each element but less than their additive sums.

Journal ArticleDOI
TL;DR: Seven years after the discovery of the chemoautotrophic sulfidic groundwater site of the Ayyalon cave, its macrofauna can be fully reviewed and consists of six endemic stygobiont and troglo-biont crustaceans and other arthropods and two species still with unclear status.
Abstract: Seven years after the discovery of the chemoautotrophic sulfidic groundwater site of the Ayyalon cave, its macrofauna can be fully reviewed. It consists of six endemic stygobiont and troglo-biont crustaceans and other arthropods and two species still with unclear status. The taxonomic list is followed by brief discussions on the systematics of the species as well as by a few comments concerning the eventual broader zoogeographical and speleological implications of the Ayyalon faunistic findings, as they appeared in literature.

Journal ArticleDOI
TL;DR: The viable count of Bacillus thuringiensis showed great capability on the biodegradation of crude oil, and these bacteria exhibit the ability to dismantle crude oil through clear emulsion layer of crudeOil.
Abstract: This study was conducted to identify the viability of Bacillus thuringiensis bacterial on a bio-degradation process for Kirkuk light crude oil. The viable count of Bacillus thuringiensis showed great capability on the biodegradation of crude oil. These bacteria exhibit the ability to dismantle crude oil through clear emulsion layer of crude oil. And they have a good efficiency to dismantle hydrocarbon compounds by 80%, and total biomass reaches to 5 g/l, while the amount of emulsion reaches to 2.3 g/l. For more evidences on the biodegradation action of Bacillus thuringiensis which have been supported by using the technology of gas-Chromatography which confirms the occurring of biodegradation process. The visual examination of gas-Chromatography shows the disappearance of a number of chemicals, as well as decrease in peak area for some material.

Journal ArticleDOI
TL;DR: In this paper, a list of mitigation projects proposed by the Egyptian government to decrease GHGs as related to the waste-to-energy projects are enumerated, which are related to waste management facilities and those which are waste to energy projects.
Abstract: Egypt is one of the most vulnerable countries to climate change due to the expected detrimental impacts on coastal zones, agriculture, water security as well as indirect social and health impacts. Egypt is responsible for 0.57% of the global greenhouse gas (GHG) emissions. Although Egypt is a non-annex I country not requiring any specific emission reduction or limitation targets under the Kyoto protocol, its National plans have included mitigation measures to reduce its greenhouse gases. The main sectors contributing to climate change in Egypt are energy, industry, agriculture and waste. Waste, on the other hand, has been accumulating in the streets of Egypt and along its water banks causing considerable air, soil and water pollution and indirect detrimental health impacts. However, this waste which is composed of organic municipal waste, agricultural residues, agro-industrial waste, animal manure and sewage sludge are valuable biomass resources. Utilizing the waste resources of Egypt especially the biomass or the organic component of this waste will not only solve some of the pressing economic needs of Egypt such as animal fodder, fertilizer and fuel but will also alleviate environmental burdens through decreasing air pollution and greenhouse gas emissions in the sector of waste as well as those of energy, industry and agriculture. This paper quantifies the biomass resources in Egypt generated from different waste resources. Then it demonstrates the efforts that Egypt made to contribute to global greenhouse gas emissions reductions through the Kyoto Protocol’s clean development mechanism (CDM). The projects in the waste sector already established in Egypt and approved as CDM projects are listed, which are related to waste management facilities and those which are waste to energy projects. Finally, a list of mitigation projects as proposed by the Egyptian government to decrease GHGs as related to the waste sector are enumerated.

Journal ArticleDOI
TL;DR: In this paper, the results of the application of the Watershed Modeling System (WMS) model showed that about 10.76 million cubic meters could be harvested, and the quantity of harvested runoff was highly affected by rainfall depth, curve number values, antecedent moisture conditions (AMC), and the area of the basins.
Abstract: Kurdistan Region (KR) of Iraq has suffered from the drought period during the seasons 2007-2008 and 2008-2009 that affected the human and economic activities of the region. Macro rainwater harvesting (Macro RWH) is one of the techniques that can ensure water availability for a region having limited water resources. This technique is based on Soil Conservation ServiceCurve Number (SCS-CN) method and the Watershed Modeling System (WMS) was used to estimate the runoff. Rainfall records of Sulaymaniyah area for the period 2002-2012 were studied and an average season was selected (2010-2011). The results of the application of the WMS model showed that about 10.76 million cubic meters could be harvested. The results also showed that the quantity of the harvested runoff was highly affected by rainfall depth, curve number values, antecedent moisture conditions (AMC) and the area of the basins.

Journal ArticleDOI
TL;DR: The analysis of the data using notion of “spots of seismic danger” shows that the seismic danger in Japan remains at high level after 2011, and some peculiarities of the seismic noise data could extract future danger time interval 2013-2014 as the danger.
Abstract: The problem of seismic danger estimate in Japan after Tohoku mega-earthquake 11 March of 2011 is considered. The estimates are based on processing low-frequency seismic noise wave-forms from broadband network F-net. A new method of dynamic estimate of seismic danger is used for this problem. The method is based on calculating multi-fractal properties and minimum entropy of squared orthogonal wavelet coefficients for seismic noise. The analysis of the data using notion of “spots of seismic danger” shows that the seismic danger in Japan remains at high level after 2011. 03. 11 within north-east part of Philippine plate—at the region of Nankai Though which traditionally is regarded as the place of strongest earthquakes. It is well known that estimate of time moment of future shock is the most difficult problem in earthquake prediction. In this paper we try to find some peculiarities of the seismic noise data which could extract future danger time interval by analogy with the behavior before Tohoku earthquake. Two possible precursors of this type were found. They are the results of estimates within 1-year moving time window: based on correlation between 2 mean multi-fractal parameters of the noise and based on cluster analysis of annual clouds of 4 mean noise parameters. Both peculiarities of the noise data extract time interval 2013-2014 as the danger.

Journal ArticleDOI
TL;DR: The paper demonstrates the actual level of chromium contamination at the site of the old tannery waste lagoon in Serniki community (SE Poland) and assumed that soil chromium content noted in 2009 was by 42% - 83% lower in relation to the data from 2004.
Abstract: The paper demonstrates the actual level of chromium contamination at the site of the old tannery waste lagoon in Serniki community (SE Poland) Despite the fact that since 1994 this area is not exploited, the chromium presence is still detected in soil, water and plants The current study is the 4th phase (after 1989, 2001 and 2004) of checking and controlling the chromium concentration in this territory The chromium content was assessed after soil and plant mineralization using FAAS method Total chromium concentrations in soil samples reached values of 225 - 1825 mg·kg-1 dry mass Levels of chromium in water samples ranged between 0008 and 0017 mg·dm-3 for Wieprz River and the trough, situated in the tannery centre, respectively Absorption of chromium by plants depended from the plant species The highest Cr content in the stalks of Oenothera biennis, whilst the lowest in Phragmites australis were detected Finally, it was assumed that soil chromium content noted in 2009 was by 42% - 83% lower in relation to the data from 2004 Consequently, nowadays the tannery waste lagoon site is not so threat to the health of local residents and to the surrounding ecosystem

Journal ArticleDOI
TL;DR: The results obtained from this study indicate that the Al-Qassim area has background radioactivity levels within the natural limits.
Abstract: Soil gas radon 222Rn concentration was measured at 12 location in the Al-Qassim area, using radon gas analyzer-type Alpha GUARD 2000 PRQ from Genitron Instruments (Germany). In each location four different depths were taken for soil gas measurements, staring from the ground surface. The results suggested that the largest concentration was 340 ± 22 Bq/m3 for 60cm depth at in Al-Tarfia point sample P3, and the smallest concentration was 26 ± 5 Bq/m3 for surface 0 cm depth at El-Bakria, point sample P5. The results obtained from this study indicate that the region has background radioactivity levels within the natural limits.

Journal ArticleDOI
TL;DR: In this paper, the concentrations of gold and associated elements in stream sediment samples from the Vaimba-Lidi drainage system in northern Cameroon were analyzed using multielement analysis and multivariate statistical interpretation.
Abstract: Stream sediment geochemistry remains a versatile tool in exploration especially in regions where knowledge of the primary mineralization is lacking and the exploration activities are still at reconnaissance stage. In this study, we investigate the concentrations of gold and associated elements in stream sediment samples from the Vaimba-Lidi drainage system in northern Cameroon; a relatively remote area where alluvial gold is worked locally, and exploration activities are at early stage. The main river and its principal first and second order tributaries were sampled, panned for gold grain recovery and the 100 μm size fraction analyzed for Au by fire assay with Ni finish. A suite of other elements were analyzed for by inductively coupled plasma mass spectrometry (ICP-MS). Gold grades estimated by the panning and weighing technique rarely exceed1 g/t while the Au concentrations from chemical analysis range from 3.0 to 354.0 ppm. The spatial distribution of gold and all the other elements are presented as point symbol maps and the data analyzed using multivariate statistics. From the principal component analysis (PCA), the As-Mo-W-Ag as well as the Au-Zn factors point to the presence of primary hydrothermal gold-sulphide mineralization in the area and this can be further investigated. These results highlight the importance of multielement analysis and multivariate statistical interpretation of sediment geochemical data in inferring the nature of the underlying primary mineralization in any region.

Journal ArticleDOI
TL;DR: The synthesis successfully links different functions of antibiotics with logical coherence and concludes that antibiotics serve a multitude of ecological functions and it is possible to visualize a pathway for the radiating functions.
Abstract: Although secondary metabolites with antimicrobial and other bioactivities are explored extensively, the natural or ecological role(s) of secondary metabolites is not yet clearly known. We review here the different hypotheses for the ecological role of antibiotics, with particular focus on the genus Streptomyces which is unparalleled in the richness of secondary metabolites. We first lay down our expectations from an ecological hypothesis for antibiotics and then weigh the six predominant hypotheses against them including antibiotics as weapons in competition, as aid in sporulation, as bartered benefits in symbioses, as signal molecules in community homeostasis, as weapons in predation and as metabolic waste or bi-products. The analysis shows that no single hypothesis meets all the expectations. While the waste or bi-product hypothesis can safely be eliminated all others have some evidence in support. It is possible therefore that antibiotics serve a multitude of ecological functions and it is possible to visualize a pathway for the radiating functions. According to this synthesis antibiotics evolved primarily as weapons in predation on other microorganisms. The inevitable co-evolution with prey species led to diversification of the genes and pathways. Some of the secondary metabolites eventually radiated to acquire other functions such as competition between predators. Some secondary metabolites evolved animal toxicity as a mutualistic barter to protect the symbiotic partner from grazing/predation by animals. Transcription modulation primarily evolved as activation of defense mechanisms by the prey which may have later radiated to serve interspecies signaling functions. The synthesis successfully links different functions of antibiotics with logical coherence.

Journal ArticleDOI
TL;DR: In this paper, the evolution of the energy use by human society is discussed, relating the energy, environmental and economic crisis, which appear to be closely linked, and the recent concept of sustainable triangular cells (2012) was introduced.
Abstract: In this paper, the evolution of the energy use by human society is discussed, relating the energy, environmental and economic crisis, which appear to be closely linked. With the widespread use of fossil fuels since the industrial revolution, a major environmental problem was generated: the climate changes. The economic consequences of climate changes are discussed in Stern (2006). Possible solutions to confront climate change are presented in the Intergovernmental Panel on Climate Change (IPCC) report (2007). Some of these solutions are based on technological development, while others do not directly depend on the technology (paradigm shifts). Faced with the needs of a new paradigm suggested by the IPCC, the recent concept of sustainable triangular cells (2012) was introduced. The geometric representation of triangular cells, which can be linked to form a regular hexagon, is used to demonstrate a sustainable society, where human cooperation prevails. This model is in line with one of the pillars of the Third Industrial Revolution, indicated by Rifkin, where an intense collaboration between individuals in human society is suggested.

Journal ArticleDOI
TL;DR: The Elgans-Group of the nematode genus Caenorhabditis is reviewed and is poised to become an important experimental system for the study of reproductive isolation.
Abstract: Reproductive isolation is the basis of the Biological Species Definition and can be a driving force of speciation. Theoretical studies have provided models of how reproductive isolation can arise within individual species. Genetic tests of these models are limited to populations in which reproductive isolation is present but not complete. Here, reproductive isolation in the Elgans-Group of the nematode genus Caenorhabditis is reviewed. Pre-mating barriers, assortative fertilization and post-zygotic barriers all have been observed in this clade. In some combinations of species, fertile F1 hybrids can be obtained. Therefore, the Elegans-Group of Caenorhabditis is poised to become an important experimental system for the study of reproductive isolation.

Journal ArticleDOI
TL;DR: Results indicated that MSOME/IMSI-selected sperm, combined with the Sperm Chromatin Dispersion test (SCD; Oligo-Halosperm), can be reliably used to assess sperm DNA damage in selected single spermatozoa (75% average efficiency), thereby establishing a direct relationship between a good morphological pattern on the sperm and a good DNA quality.
Abstract: Sperm of poor quality may affect syngamy after fertilization, embryo development up to the blastocyst stage and reproductive outcome. Subsequently, sperm selection based on morphological characteristics and sperm DNA quality may help to partially avoid these problems. Today, highly efficient sperm selection based on morphological characteristics can be attained using the motile sperm organelle morphology (MSOME) examination, and the spermatozoa selected can be used for ICSI through a fertilization strategy known as intra-cytoplasmic morphologically selected sperm injection (IMSI). The aim of this investigation was to develop a simple methodology to assess sperm DNA fragmentation in single spermatozoa following MSOME/ IMSI, to test the hypothesis that morphologically normal spermatozoa, with an absence of vacuolization, is free of DNA damage. The results indicated that MSOME/IMSI-selected sperm, combined with the Sperm Chromatin Dispersion test (SCD; Oligo-Halosperm), can be reliably used to assess sperm DNA damage in selected single spermatozoa (75% average efficiency), thereby establishing a direct relationship between a good morphological pattern on the sperm and a good DNA quality. Furthermore, results showed spermatozoa presenting a normal morphology and no traces of vacuolization to be fully free of DNA damage. However, traces of vacuolization and more severe morphological alterations were accompanied by significant increases in the proportion of sperm containing a damaged DNA molecule. Interestingly, subtle morphological differences observed between normal and non-vacuolated and normal but vacuolated sperm exhibited significant differrences in the ability of the SCD-Oligo-Halosperm treated sperm to expand DNA fibers following protein depletion.

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TL;DR: In this article, the authors investigated mining in the Coal River watershed in West Virginia, USA, using landform terrain analysis, utilizing light detection and ranging (LiDAR)-derived elevation data, indicated specific landform types and distributions that were significantly altered after mountaintop removal and reclamation.
Abstract: A comprehensive impact analysis of mountaintop removal and valley fill (MTR/VF) mining requires an understanding of landform alterations since ecological impacts are so intricately linked. In this study we investigated mining in the Coal River Watershed, West Virginia, USA, using landform terrain analysis. Previous studies have relied on elevation differencing of pre- and post-mining surfaces to assess absolute elevation and volumetric change. Our landscape analysis, utilizing light detection and ranging (LiDAR)-derived elevation data, indicated specific landform types and distributions that were significantly altered after MTR/VF mining and reclamation. The use of categorical landform data provides insights to assessing and understanding the extent of topographically altered mountaintops. Our study provides an opportunity to further examine the impact of MTR/VF on forest communities, terrestrial habitat, ecosystem health, and biodiversity.

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TL;DR: The obtained results support the possible use of some wild edible plants as a source of phenolic substances for the postharvest biological control of fresh fruit and vegetable rots.
Abstract: The chemical characterization of phenolic extracts of salad burnet (Sanguisorba minor Scop. s.l.) and broomrape (Orobanche crenata Forsk.) was performed. Active fractions were separated and characterized and, in the case of O. crenata, two phenolic compounds, verbascoside and is overbascoside, were quantitatively extracted, purified and characterized. These compounds proved to be effective in reducing the growth of some important fungi responsible for the decay of fresh fruit and vegetables in postharvest. Verbascoside showed significant activity against Penicillium italicum, fairly inhibited Monilinia laxa, P. expansum, and Aspergillus carbonarius, and showed little activity against Botrytis cinerea, M. fructicola and P. digitatum. Isoverbascoside completely inhibited B. cinerea, P. digitatum, P. italicum, and P. expansum; it fairly inhibited M. laxa and A. carbonarius; while it showed to be less effective against M. fructicola. The obtained results support the possible use of some wild edible plants as a source of phenolic substances for the postharvest biological control of fresh fruit and vegetable rots.

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TL;DR: The early white shark Carcharodon Smith, 1838 with the fossil C Archarodon auriculatus and the extinct megatooth shark Otodus Agassiz, 1843 with species Otodus sokolovi were both present in the European proto North Sea Basin about 47.8 - 41.3 m.y. ago.
Abstract: The early white shark Carcharodon Smith, 1838 with the fossil Carcharodon auriculatus (Blainville, 1818) and the extinct megatooth shark Otodus Agassiz, 1843 with species Otodus sokolovi (Jaeckel, 1895) were both present in the European proto North Sea Basin about 47.8 - 41.3 m.y. ago (Lutetian, early Middle Eocene), as well as in the Tethys realm around the Afican-Eurasian shallow marine habitats. Both top predators developed to be polyphyletic, with possible two different lamnid shark ancestors within the Early Paleocene to Early Eocene timespan with Carcharodon (white shark line-age) and Otodus (megatooth shark lineage). Their sawblade teeth developed during the early Paleogene as the result of adaptation to feeding on various marine new rising mammals, coinciding with three main waves of evolutionary emergence of seals, sirenians, and whales in parallel with the evolution of these large predatory sharks. Megatooth sharks specialized in hunting whales and sirenians only on the coastal shelves of warm oceans and disappeared globally in the Pleistocene due to climate change and ocean cooling. The cold-water adapted early white sharks have survived until the present day with body temperate change adaptation in warm to temperate oceans and are proposed to have specialized on coastal seal hunting already50 m.y. ago.

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TL;DR: This review tries to address the survival mechanisms of Mycobacterium avium subspecies paratuberculosis in the different host species and adverse environmental conditions in order to allow designing of more rational diagnostic and control procedures.
Abstract: Mycobacterium avium subsp. paratuberculosis causes chronic inflammation of the intestine known as Johne’s disease (JD) in domestic and wild ruminants including primates. MAP has also been associated with inflammatory bowel disease (IBD) so called Crohn’s disease (CD) of human beings, which is incurable even after surgery. By virtue of the pasteurization resistant power, high endemicity of the infection in animals continues to be the permanent source of infection to human population. High bio-burden of MAP in wide range of biotic (animal hosts including human beings) and abiotic environment in each and every country where it has been investigated, serves a reminder about the survival abilities of the MAP in diverse range of environmental conditions. Ability of the MAP to evade immune system of the host and the temporal events during infection of the macro-phages, is an area of major concern and research activities as the pattern of distribution are quiet different from those of other pathogenic intracellular organisms. Moreover, the organism can survive over a wide range of environmental conditions such as high and low environmental temperatures, pasteurization, low pH, and high salt concentration etc. This superior survival efficiency from environmental degradation and dormancy within host allows the pathogen to be available for causing disease and pathogenicity in animals and human beings, when conditions are favorable. Perusal of literature reveal that, despite the availability of whole genome sequence of MAP, a very little is known about the replication, persistence and survival mechanisms of this pathogen. Therefore, this review tries to address the survival mechanisms of Mycobacterium avium subspecies paratuberculosis in the different host species and adverse environmental conditions in order to allow designing of more rational diagnostic and control procedures.

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TL;DR: In this paper, SHRIMP U-Pb analysis on detrital zircons obtained from these metasediments gave variable ages from over 3000 Ma to 1000 Ma with the maximum age of deposition clustered around 1200 Ma and the peak of deposition at 1800 Ma.
Abstract: Banded Iron Formations (BIFs) were formed by contemporaneous events of active sediments supply and the venting of a hydrothermal fluid source at the Mid-Ocean-Ridge. BIFs within the Ntem Complex at the northern edge of the Congo Craton are intercalated with metasandstones and siltstones. SHRIMP U-Pb analysis on detrital zircons obtained from these metasediments gave variable ages from over 3000 Ma to 1000 Ma with the maximum age of deposition clustered around 1200 Ma and the peak of deposition at 1800 Ma. This age range suggested that the sub-basin was opened sometime in the Archean and remained active up till the Neoproterozoic. Zircons with Archean ages have a provenance linked to the charnockitic suite and the high-K granites within the Ntem Complex. The Paleoproterozoic ages are attributed to clastic inputs from the neigbouring Nyong Series west of the Ntem Complex. Also the peak of deposition in the Proterozoic could probably be explained by the globally recognized intense crust-forming processes in the Early Proterozoic time. The provenance of the younger Neoproterozoic ages is tied to various lithologies within the northern mobile belts of the Adamawa-Yade massifs and correlates with Neoproterozoic sedimentation ages in the Yaounde, Lom and Poli series. The Neoproterozoic ages obtained are comparable to those obtained from metasediments of the Amazonian Craton and provide evidence of Pre-Gondwana assemblage of the Congo and the S?o Francisco Cratons.

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TL;DR: The article shows that the global warming has entailed the increase of the Lake Issyk-Kul water temperature down to the maximum depths, and river discharge increase due to the glaciers melting and the evaporation from the lake surface.
Abstract: Lake Issyk-Kul is the seventh deepest lake in the world situated inCentral Asiain theTien-ShanMountainsat the elevation of 1607 m above sea level. This area belongs toKyrgyzstan. From 1927 to 1997 the water level decreased by 3.4 m, and increased by 0.93 m from 1997 to 2011. The article analyzes the impact of the global warming on the Lake Issyk-Kul thermal regime and the components of its water balance: river discharge, precipitation, evaporation and lake level variations. It shows that the global warming has entailed the increase of the Lake Issyk-Kul water temperature down to the maximum depths, and river discharge increase due to the glaciers melting and the evaporation from the lake surface. The air temperature increase of 1 ℃ results in river discharge increas and lake level rise of 44 mm/year and surface evaporation increase of 88 mm/year. TheLakeIssyk-Kullevel increase after 1997, which takes place in the situation of global warming, was caused by the activation of the West air masses transport and increase of precipitation in autumn.