The relative importance of sexual reproduction and clonal propagation in rhizomatous herb Iris japonica Thunb. from two habitats of Jinyun Mountain, Southwest China

Reproductive behaviour of clonal plants might change in contrasting habitats. In field and simulated experiments, we studied the relative importance of sexual reproduction and clonal propagation in rhizomatous herb, Iris japonica Thunb. in two forest habitats (BF, bamboo forest and OAFE, open area of forest edge), and effects of population origin (BF vs. OAFE) and environmental effects (shading) on sexual vs. clonal reproduction. In field experiment, the relative importance of reproduction in I. japonica populations was different in two habitats, which showed predominantly sexual reproduction in OAFE and clonal propagation in BF. In simulated experiment, the effect of population origin and light treatment (shading) was significant for reproduction of I. japonica. Clonal propagation was only influenced by population origin, and sexual reproduction was determined both by population origin and light treatment. A trade-off between two reproductive modes exhibited in both experiments. The trade-offs was more obvious in OAFE than in BF because sexual reproduction, resource and inter-specific competition obviously lacked in BF. The results indicated that the selective forces shaping reproduction of I. japonica in contrasting habitats might demonstrate pronounce adaptive population differentiation among forest habitats. Thus, I. japonica populations formed local differentiation by adaptation of reproduction to local heterogeneous forest habitats.     

Hormonal response to conspecific chemical signals as an indicator of seasonal reproduction dynamics in the desert hamster, Phodopus roborovskii

Changes in male blood plasma testosterone and cortisol in response to exposure to scent marks (urine and midventral gland secretion, MVGS) of conspecific males and diestrous females in different seasons have been studied in the desert hamster (Phodopus roborovskii), a species whose ecological features are poorly known. The results show that a significant increase in the plasma testosterone level is observed in winter (only to female MVGS), spring (to female MVGS and urine), and summer (to female urine), but not in autumn. The level of plasma cortisol significantly increases only in response to female urine in spring and male MVGS in summer.     

Ecotoxicological effects of an aged TiO2 nanocomposite measured as apoptosis in the anecic earthworm Lumbricus terrestris after exposure through water, food and soil

Titanium dioxide nanoparticles seem to have a low toxicity to terrestrial organisms, though few studies are published in this area. TiO(2) used in sunscreens are nanocomposites where TiO(2) has been coated with magnesium, silica or alumina, as well as amphiphilic organics like polydimethyl siloxane (PDMS), and these coatings are modified by ageing. We assessed the ecotoxicity and propensity for bioaccumulation of an aged TiO(2) nanocomposite used in sunscreen cosmetics, and its potential effect on the frequency of apoptosis in different earthworm tissues. The earthworm Lumbricus terrestris was exposed to the TiO(2) nanocomposite for 7 days in water or 2-8 weeks in soil with the nanocomposite mixed either into food or soil at concentrations ranging from 0 to 100 mg kg(-1). Apoptosis was then measured by immunohistochemistry and Ti localized by XRF microscopy. Results showed no mortality, but an enhanced apoptotic frequency which was higher in the cuticule, intestinal epithelium and chloragogenous tissue than in the longitudinal and circular musculature. TiO(2) nanoparticles did not seem to cross the intestinal epithelium/chloragogenous matrix barrier to enter the coelomic liquid, or the cuticule barrier to reach the muscular layers. No bioaccumulation of TiO(2) nanocomposites could thus be observed.     

Toxicity of zinc oxide nanoparticles in the earthworm, Eisenia fetida and subcellular fractionation of Zn

The extensive use of nanoparticles (NPs) in a variety of applications has raised great concerns about their environmental fate and biological effects. This study examined the impact of dissolved organic matter (DOM) and salts on ZnO NP dispersion/solubility and toxicity to the earthworm Eisenia fetida. To be able to better evaluate the toxicity of NPs, exposure in agar and on filter paper was proposed for enabling a comparison of the importance of different uptake routes. A dose-related increase in mortality was observed in earthworms exposed in agar with almost 100% mortality after 96 h exposure to the highest concentration (1000 mg ZnO/kg agar). Scanning electron microscopy (SEM) showed that the addition of salts enhanced the aggregation of ZnO NPs in agar and consequently affected the dissolution behavior and biological availability of the particles. On filter paper, mortality was the highest at the lowest exposure concentration (50 mg ZnO/L) and seemed to decrease with increasing exposure levels. TEM images of ZnO showed that the solubility and morphology of NPs were changed dramatically upon the addition of humic acids (HA). The subcellular distribution pattern of Zn in earthworms after 96 h exposure in agar and on filter paper showed that the Zn taken up via dietary ZnO particles (from agar) was mainly found in organelles and the cytosol while the Zn accumulated as soluble Zn from filter paper was mainly distributed in cell membranes and tissues. Antioxidant enzymatic activities (SOD, CAT, and GSH-px) were investigated in the worms surviving the toxicity tests. A slight increase of SOD activities was observed at the lowest exposure dose of ZnO (50mg/kg), followed by a decrease at 100mg/kg in the agar cubes. Activities of both CAT and GSH-Px enzymes were not significantly influenced in the worms exposed to agar, although a slight decrease at 500 and 1000 mg ZnO/kg agar was observed. A similar change trend of SOD activities was observed for the earthworms on filter paper, but a significant decrease began at a higher ZnO NP concentration of 500 mg ZnO/L. The use of soil extracts instead of deionized water (DW) to simulate a realistic exposure system significantly reduced the toxicity of the ZnO NPs on filter paper, which increases the predictive power of filter paper toxicity tests for the environmental risk assessment of NPs.     

Assessment of sociocultural acceptability of biogas from faecal waste as an alternative energy source in selected areas of Benin City,Edo State,Nigeria

Environment, Development and Sustainability - The use of wastes for biogas production has been restricted to few feedstock like cattle manure and food waste. Increasing the feedstock base for...     

Diversity,utilization pattern and representativeness of dye yielding plants in North Western and Western Himalaya,India: an untapped source for Bioprospection

Environment, Development and Sustainability - Natural colorants or dyestuffs are an essential faction of non-timber forest products that are widely used for coloring purposes in various industries....     

Estimates of energy expenditures for reproduction in the pied flycatcher Ficedula hypoleuca Pall. in an industrially polluted environment

Energy expenditures for reproduction in local populations of the pied flycatcher in the environs of the Middle Urals Copper Smelter (Revda, Sverdlovsk oblast) have been estimated on the basis of the results of long-term studies (1989?C2008). It is shown that the total energy expenditures per fledgling over the nesting period are 1.2 times higher than in the background area, which is explained by increased energy losses (by a factor of 4.1) resulting from partial mortality of the progeny (eggs or nestlings). Variation in the average energy ??cost?? of one fledgling in the heavily polluted zone is also higher, compared to the background area. Average energy expenditures per fledgling increase in years with cold weather, and the same is observed when the birds lay larger clutches.     

The structure of genotypic diversity and the possibility of sexual reproduction in populations of <Emphasis Type="Italic">Tulipa riparia</Emphasis> (Liliaceae)

The structure of genotypic diversity in eight populations of the clonal triploid (2n = 3x = 36) tulip Tulipa riparia inhabiting floodplain communities in the Southern Urals was studied. Analysis of nine polymorphic enzyme systems (ADH, IDH, SkDH, PGI, PGM, FDH, NADHdh, C-EST, GOT) was performed to identify clones. Both monoclonal (D = 0) and polyclonal populations with multiple genotypes from 3 to 12 (D from 0.73 to 0.91) were identified. The polyclonal populations had a high level of heterozygosity. Dispersal of propagules (bulbs) along rivers and even from one bank of a river to the opposite was detected. Some clones disperse along riverbanks to the distance of hundreds meters (up to four kilometres). At the same time, there is an effect of “isolated” or “closed” populations. Almost each sequentially arranged population in one river system have its own set of genotypes. Assessment of the state of the reproductive system components indicates presence of a rare sexual reproduction supporting genetic diversity of T. riparia.     

The source of anomalous radioactivity in the springs bordering the Sea of Galilee, Israel

Situated within the Jordan Rift Valley, along the shores of Lake Kinneret (Sea of Galilee) which serves as the national water reservoir of Israel, are saline hot springs that are notable for their enrichment in radon and radium. Though the anomalous radioactivity has been known for almost half a century, the source of the radioactive anomalies has been a subject of conjecture. Radiometric analysis of a rock core drilled through Mt. Arbel, situated to the west of the lake, reveals that the oil shale sequence of the Senonian En Zetim and Ghareb formations is strikingly deficient in radium. Mt. Arbel has been cut by Rift Valley related faults that serve as conduits for ascending brines. The organic matter enriched sequence is encountered in the subsurface at elevations lower than the water level of the nearby radioactive enriched hot springs. It is thus concluded that hot ascending brines underlying the lake flush through the organic matter enriched sequence and remove a substantial percentage of 226Ra from the uranium enriched organic material, before draining to the outlets of the springs. Saline springs that are in contact with organic matter enriched sequence show excess of radium and radon, while fresh water springs in the same stratigraphic position show only excess of radon.     

Gamma dose rates and distribution of natural radionuclides in sand beaches--Ilha Grande, Southeastern Brazil

In order to study the process of dispersion and the activity concentration of 232Th and 238U series and 40K radionuclides in two island beaches in southeastern Brazil, analyses was made of sand samples of 0-10 cm profile, during a 12-month period. Moreover, the monthly variations of gamma dose rates were studied to determine the local environment absorbed dose rate. The average activity concentration of primordial radionuclides 232Th, 238U and 40K at Preta beach, they were 239, 121 and 110 Bq kg(-1), while at Dois Rios beach they were 48, 39 and 412 Bq kg(-1), respectively. The absorbed dose rate in air, observed at 1 m above the ground, ranged from 54 to 228 nGy h(-1) at Preta beach and from 39 to 110 nGy h(-1) at Dois Rios beach. The annual effective dose equivalent corresponding to Preta beach is 0.15 mSv a(-1) and to Dois Rios 0.08 mSv a(-1).     

Impacts of snow disaster on meat production and adaptation: an empirical analysis in the yellow river source region

The Yellow River source region is located in the hinterland of the Qinghai-Tibetan Plateau, and has a sensitive response to global change due to its unique cryosphere processes. Any slight changes in natural elements and human activity can have a magnified effect on grassland ecosystem, animal husbandry, and pastoral livelihoods since its economy is exclusively dominated by grassland animal husbandry. Because snow disaster has been one of the major natural disasters in the source region, it is crucial to explore the economic impact of snow disaster on animal husbandry and identify effective adaptation measures. A nonlinear model of meat production was established in relation to snow disaster, grassland productivity, and disaster prevention by introducing a snow level index, and selecting three key indicators of grassland productivity and disaster prevention, including grass growing season precipitation concentration, sown grassland area, and warm barn area. This is an inverse of negative correlation, less meat when there is more snow. Per unit increase in snow level in the source region led to a decrease of 0.213 units in meat production. However, production losses caused by the snow disaster could be effectively suppressed by the increase in scale and intensity of sown grassland and warm barn construction. Per unit increase in sown grassland and warm barn area led to an increase of 0.240 and 0.610 units in meat production, respectively. The effects of sown grassland and warm barn area in reducing snow damage at different snow levels were analyzed. Snow disaster adaptation in the source region should include acceleration of the construction of meteorological disaster prevention and mitigation system, to ensure balanced forage supply between winter and spring, to prioritize the development of warm barn, and reduce the proportion of self-financed construction warm barn to encourage active participation of pastoralists, and to develop insurance mechanism for livestock.     

Radionuclide content of concrete building blocks and radiation dose rates in some dwellings in Ibadan, Nigeria

Thirty-two samples of concrete building blocks were collected from different block making industries in Ibadan. The radioactivity concentrations of the natural radionuclides in the samples were determined by gamma-ray spectrometry with a NaI(Tl) detector. The radioactivity concentrations varied from 6.2 to 57.5 Bq kg(-1), 12.4 to 64.9 Bq kg(-1) and 95.3 to 766.1 Bq kg(-1) for 226Ra, 232Th and 40K, respectively. The radium equivalent activities of the 32 samples varied from 51.3 to 175.7 Bq kg(-1). Radiation exposure levels in 30 dwellings were determined using LiF thermoluminescent dosimeters. The annual equivalent dose rates varied from 0.318 to 0.657 mSv y(-1) with a mean of 0.433 mSv y(-1). The annual effective dose rate to the whole body was calculated as 0.236 mSv y(-1), which is less than that (mean) estimated by UNSCEAR for normal background areas.     

Persistent organic pollutants in breast milk of mothers residing around an open dumping site in Kolkata,India: Specific dioxin-like PCB levels and fish as a potential source

Concentrations of persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and organochlorine pesticides were measured in human breast milk collected from mothers residing near an open dumping site and a reference site in Kolkata, India during 2004–2005. POPs were detected in all the human milk samples analyzed, suggesting that residents of Kolkata are widely exposed to these contaminants. Concentrations of dioxin-like PCBs in the samples from the dumping site were significantly higher than in the reference site samples, whereas no such difference was found for PCDDs and PCDFs. In addition, significantly higher concentrations of total PCBs were also observed in the samples from the dumping site than the reference site. Interestingly, concentrations of total and dioxin-like PCBs in the breast milk of mothers from the dumping site significantly increased with the number of years of residence near the dumping site. These results indicate that significant pollution sources of PCBs are present in the dumping site of Kolkata and the residents living around are exposed to relatively higher levels of PCBs. When the residue levels of dioxins and related compounds in fish collected from ponds near the Kolkata dumping site and the reference site were measured, it was found that dioxin-like PCB and TEQ levels in fish from the dumping site were notably higher than those from the reference site. This result indicates that fish is a potential source of PCBs for residents living near the Kolkata dumping site.     

Understanding levels and trends of BDE-47 in the UK and North America: an assessment of principal reservoirs and source inputs

Despite increasing interest in the occurrence of Polybrominated diphenyl ethers (PBDEs) in the environment, there has been only limited effort expended to identify principal source input reservoirs and pathways into the environment. Taking a single congener BDE-47, an important component of the penta commercial product, we have estimated principal contemporary reservoirs and emissions in two regions with very different historical use patterns. In North America, production and use of the penta-product has been rising steadily for the last 20 years, whilst in the UK, use has been restricted over the last 10 years, and most recently, there has been an EU ban on use. Mass balance models have been applied using our contemporary emission estimates to predict environmental levels. Results highlight that contemporary emissions to air can account for contemporary air concentrations but cannot account for measured concentrations in principal reservoirs such as soils and sediments. Future efforts are needed to improve our knowledge of the stocks of PBDEs in use, and emission factors from those stocks, to better understand/predict past and likely future trends.     

Estimation of annual effective dose due to natural radioactive elements in ingestion of foodstuffs in tin mining area of Jos-Plateau, Nigeria

Soils and food crops from a former tin mining location in a high background radiation area on the Jos-Plateau, Nigeria were collected and analyzed by gamma spectrometry to measure their contents of 40K, 238U and 232Th. As well as collecting samples, in situ dose rates on farms were measured using a precalibrated survey meter. Activity concentrations determined in food crops were compared with the local food derivatives or diets to investigate the possible removal or addition of radionuclides during food preparation by cooking or other means. Potassium-40 was found to contribute the highest activity in all the food products. The activity concentration of 40K, 238U and 232Th in local prepared diets ranged between 60 and 494 Bq kg-1, between BDL and 48 Bq kg-1 and between BDL and 17 Bq kg-1, respectively. The internal effective dose to individuals from the consumption of the food types was estimated on the basis of the measured radionuclide contents in the food crops. It ranged between 0.2 microSv y-1 (beans) and 2164 microSv y-1 (yam) while the annual external gamma effective dose in the farms due to soil radioactivity ranged between 228 microSv and 4065 microSv.     

Uranium-238 and thorium-232 series concentrations in soil, radon-222 indoor and drinking water concentrations and dose assessment in the city of Aldama, Chihuahua, Mexico

High-resolution gamma spectrometry was used to determine the concentration of 40K, 238U and 232Th series in soil samples taken from areas surrounding the city of Aldama, in Chihuahua. Results of indoor air short-time sampling, with diffusion barrier charcoal detectors, revealed relatively high indoor radon levels, ranging from 29 to 422 Bq/m3; the radon concentrations detected exceeded 148 Bq/m3 in 76% of the homes tested. Additionally, liquid scintillation counting showed concentrations of radon in drinking water ranging from 4.3 to 42 kBq/m3. The high activity of 238U in soil found in some places may be a result of the uranium milling process performed 20 years ago in the area. High radon concentrations indoor and in water may be explained by assuming the presence of uranium-bearing rocks underneath of the city, similar to a felsic dike located near Aldama. The estimated annual effective dose of gamma radiation from the soil and radon inhalation was 3.83 mSv.     

(238)U, (234)U, (226)Ra, (210)Po concentrations of bottled mineral waters in Italy and their dose contribution

Due to the importance of bottled mineral water in human diet with special regard to children in lactation period, a monitoring of natural radioactivity in some bottled mineral waters produced in Italy was performed. Gross alpha and beta activities and (226)Ra, (238)U, (234)U, and (210)Po concentrations were measured. Gross alpha and beta activities were determined by standards ISO 9696 and ISO 9697; for (226)Ra determination liquid scintillation was used. The (238)U and (234)U concentrations were determined by alpha spectrometry after their separation from matrix by extraction chromatography and electroplating. (210)Po was measured by alpha spectrometry. The results revealed that the concentrations (mBqL(-1)) of (226)Ra, (238)U, (234)U, and (210)Po ranged from <10.00 to 52.50, from <0.17 to 89.00, from <0.17 to 79.00, and from <0.04 to 21.01, respectively. Uranium and radium concentrations do not reach the relevant recommended derived activity concentration (DWC). For polonium concentration, none of the samples reaches the relevant DWC in the case of adults and children, but one sample exceeds this value for infants. The dose contribution for different classes of age was calculated using the dose coefficient factors reported by EC Directive 96/29 EURATOM and certain annual intake. For children and adult age class, the calculated doses are quite similar and lower than 0.1mSvy(-1); for infants (<1y) in three cases the calculated dose ranges from 0.11 to 0.17mSvy(-1).     

Influence of silts on the growth,reproduction and chlorophyll fluorescence of <Emphasis Type=Italic>Potamogeton crispus</Emphasis> in turbid water

Turions of Potamogeton crispus were planted in several turbid waters. Some parameters of growth, reproduction and chlorophyll fluorescence were measured. The results were as follows: (1) Sprouting rates in all groups reached to 100.0% on the 17^th day. (2) The parameters of the growth (stem and leaf) and chlorophyll fluorescence (Φ_PSII, qP and qN) in 120 and 150NTU waters were inhibited heavily 60 days later, and their survival time was only 140 days. However, the plants in 30 to 90NTU waters could grow near water surface, their survival time was about 190 days. (3) After 150 days, the saturating irradiance intensity and rETR_max of the leaves in 30 to 90NTU waters markedly decreased with an increase in the amount of attached silts, and the number and fresh mass of turions (propagula) in 60 and 90NTU waters were significantly lower than the control. In summary, P. crispus in 0.7-metre-deep turbid water with suspended silts (not more than 90NTU) could sprout and grow normally, and produce the turions.     

Determination of lead,chromium and zinc in sediments from an urbanized river in Mauritius

The mean concentration of Cr (105 +/- 30 mg kg(-1)), Zn (167 +/- 30 mg kg(-1)) and Pb (14 +/- 7 mg kg(-1)) in the sediments along St. Louis River situated in an urbanized and industrialized area in Mauritius were well below the limits of 600, 2500 and 700 mg kg(-1) quoted for contaminated sediments adopted from the draft standards (24% clay and 10% organic matter by weight) from the Netherlands [Van Veen RJ, Stortelder PBM. Research on contaminated sediments in the Netherlands. In: Wolf K, Van de Brink WJ, Colon FJ, editors. Contaminated soil. Academic Publisher, 1998. p. 1263-1275.]. Industrial contamination appeared to undergo rapid dilution in the estuary as Cr had high levels near point sources from industries, but decreased rapidly in amount in the estuary possibly because of dilution by other sediments. The significant levels of Zn in sediments from upstream to the estuary suggest that the potential sources could be from the adjacent motorway and road runoff causing significant quantities to be trapped within the St. Louis River. Pb was two folds higher in the sediments in the estuary of St. Louis River compared to upstream and downstream indicating accumulation of Pb in estuarine sediments, which could be released continuously into the lagoon. The potential sources of Pb in sediments from upstream to the estuary were from the adjacent motorway and road runoff causing significant quantities to be trapped within the St. Louis River. Pb and Zn were significantly positively correlated in the sediments along St. Louis River indicating a common source for Pb and Zn. Significant negative correlations were also found for both Pb and Zn with dissolved oxygen in summer along St. Louis River which indicated that the presence of anoxic waters influenced the trapping of Zn and Pb in the sediment phase. This study has also highlighted that a phasedown of Pb in petrol is necessary and with the introduction of unleaded petrol and vehicles equipped with catalytic converters, studies on levels of Pd and Pt to provide baseline data need to be done in the near future and integrated in environmental development schemes and effective coastal zone management of small island states.     

Growth and potential reproduction of <Emphasis Type="Italic">Poa crymophila</Emphasis> in response to season precipitation shortage in the Eastern Tibetan Plateau,China

The growing season in 2006 existed a quite less precipitation than previous years in the eastern of Tibetan Plateau, China. In order to explore the response strategies of the grass to drought year, the variations of growth and potential reproduction of Poa crymophila between rich (2005) and poor rainfall year (2006) were studied. Reproductive shoot biomass, above- and below-ground biomass pronounced decreased in the poor rainfall year, but the ratio of above-/below-ground biomass and vegetative shoot biomass increased. Carbon content in inflorescence increased significantly in 2006, but decreased significantly in root. Nitrogen contents and the C/N ratios in plant components were not significantly different. Sexual reproduction in 2005 and 2006 was not different. Season precipitation shortage could result in the higher mortality of vernal budding shoots or tillers. The results suggested that P. crymophila response to poor rainfall year (drought) by a smaller plant body, allocating more proportional biomass to above-ground, altering more carbon to inflorescence, and altering its reproductive way to sexual.