Macronutrients (N, P, K, Ca, Mg, and S) in litter of three primarily spruce (Picea purpurea Masters) (SF), fir (Abies faxoniana Rehder & E. H. Wilson) (FF), and birch (Betula platyphylla Sukaczev) (BF) ...Macronutrients (N, P, K, Ca, Mg, and S) in litter of three primarily spruce (Picea purpurea Masters) (SF), fir (Abies faxoniana Rehder & E. H. Wilson) (FF), and birch (Betula platyphylla Sukaczev) (BF) subalpine forests in western China were measured to understand the monthly variations in litter nutrient concentrations and annual and monthly nutrient returns via litteffall. Nutrient concentration in litter showed the rank order of Ca 〉 N 〉 Mg 〉 K 〉 S 〉 P. Monthly variations in nutrient concentrations were greater in leaf litter (LL) than other litter components. The highest and lowest concentrations of N, P, K, and S in LL were found in the growing season and the nongrowing season, respectively, but Ca and Mg were the opposite. Nutrient returns via litterfall showed a marked monthly pattern with a major peak in October and one or two small peaks in February and/or May, varying with the element and stand type, but no marked monthly variations in nutrient returns via woody litter, reproductive litter, except in May for the BF, and moss litter. Not only litter production but also nutrient concentration controlled the annual nutrient return and the monthly nutrient return pattern. The monthly patterns of the nutrient concentration and return were of ecological importance for nutrient cycling and plant growth in the subalpine forest ecosystems.展开更多
A Chinese fir forest (Cunninghamia lanceolata, CF) and an evergreen broadleaved forest (EB) located inFujian Province, southeastern China, were examined following slash burning to compare nutrient capital andtopsoil p...A Chinese fir forest (Cunninghamia lanceolata, CF) and an evergreen broadleaved forest (EB) located inFujian Province, southeastern China, were examined following slash burning to compare nutrient capital andtopsoil properties with pre-burn levels. After fire, nutrient (N, P and K) removal from burning residues wasestimated at 302.5 kg ha-1 in the CF and 644.8 kg ha-1 in the EB. Fire reduced the topsoil capitals of totalN and P by about 20% and 10%, respectively, in both forests, while K capital was increased in the topsoils ofboth forests following fire. Total site nutrient loss through surface erosion was 28.4 kg (N) ha-1, 8.4 kg (P)ha-1 and 328.7 kg (K) ha-1 in the CF. In the EB, the losses of total N, P and K were 58.5, 10.5 and 396.3kg ha-1, respectively. Improvement of soil structure and increase in mineralization of nutrients associatedwith increased microbe number and enzyme activities and elevated soil respiration occurred 5 days after fire.However, organic matter and available nutrient contents and most of other soil parameters declined one yearafter fire on the burned CF and EB topsoils. These results suggest that short-term site productivity canbe stimulated immediately, but reduced subsequently by soil and water losses, especially in South China,where high-intensity precipitation, steep slopes and fragile soil can be expected. Therefore, the silviculturalmeasurements should be developed in plantation management.展开更多
Four species of African giant land snails (Archachatina marginata (ovum ) Pfeiffer, Archachatina marginata (saturalis ) Philippi, Achatina achatina and Limicolaria spp.) were assessed for their proximate and min...Four species of African giant land snails (Archachatina marginata (ovum ) Pfeiffer, Archachatina marginata (saturalis ) Philippi, Achatina achatina and Limicolaria spp.) were assessed for their proximate and mineral compositions aimed at establishing their nutritive values on wet weight basis. Analysis of muscle revealed that composition of crude protein varied from 18.66%±0.57% in Limicolaria spp. and 20.56%±L0.05% in Archachatina marginata (ovum) Pfeiffer; moisture content was 76.56%±0.04% in Archachatina marginata (ovum) Pfeiffer and 78.68%±0.68% in Limicolaria spp. and ash was 1.34%±0.02% in Achatina achatina and 1.44%±0.01% in Archachatina marginata (ovum) Pfeiffer. These values were statistically different from each other (P〈0.05). Carbohydrate and fat content were generally low. Crude fibre was not detected in any of the species. The concentrations of zinc, iron, manganese, magnesium, calcium, phosphorus, sulphur, potassium and sodium in the flesh of the snails were determined. Values of iron, magnesium, calcium, phosphorus, potassium and sodium were consistently high while cobalt, copper and lead were not detected. Snails complement the required trace and minor elements needed for proper growth and development in human being, so it is recommended for regular consumption.展开更多
Inadequate quality and quantity diet is one of the major reasons for high levels of malnutrition in pregnant women. A cross-sectional survey was conducted in Wondo Genet District, Southern Ethiopia. A two-stage cluste...Inadequate quality and quantity diet is one of the major reasons for high levels of malnutrition in pregnant women. A cross-sectional survey was conducted in Wondo Genet District, Southern Ethiopia. A two-stage cluster sampling technique was used to select a representative sample of 153 pregnant women aged 19-49 years from three rural villages ("Kebeles"). Energy and nutrient intakes from foods were calculated from one-day weighed food records on a sub-sample (n = 77). The result of the study showed that the intakes of most nutrients were lower than the recommended intake. The energy intake of the study participants both in 2nd and 3rd trimesters of pregnancy were 2,308 kcal and 1,420.5 kcal compared to the recommended 2,340 kcal and 2,452 kcal, respectively. Except iron, almost all micronutrient intakes were lower than the recommended intake. Vitamin A intake was 3/ag compared with the recommended 800μg, while protein intake of the study respondents in 2nd and 3rd trimester of pregnancy was 45.9 g and 31.5 g, respectively, compared with the recommended 71 g. Risk factors for undernutrition were multiple pregnancy and no consumption of cereal-based foods. This study revealed that the energy and nutrient intake of the pregnant women in study area was below the recommended intakes. Furthermore, the situation might be aggravated by high phytate content food consumption reported. Nutritional status of pregnant women in study area was not adequate to support the increased energy and nutrient requirement of the participants.展开更多
Iron is a critical micronutrient, and iron derived from heme contributes a large proportion of the total iron absorbed in a typical Western diet. Heme iron is absorbed by different mechanisms than non-heme iron, but d...Iron is a critical micronutrient, and iron derived from heme contributes a large proportion of the total iron absorbed in a typical Western diet. Heme iron is absorbed by different mechanisms than non-heme iron, but despite considerable study over many years these mechanisms remain poorly understood. This review provides an overview of the importance of heme iron in the diet and discusses the two prevailing hypotheses of heme absorption; namely receptor mediated endocytosis of heme, and direct transport into the intestinal enterocyte by recently discovered heme transporters. A specific emphasis is placed on the questions surrounding the site of heme catabolism and the identity of the enzyme that performs this task. Additionally, we present the hypothesis that a non-heme iron transport protein may be required for heme iron absorption and discuss the experiences of our laboratory in examining this hypothesis.展开更多
Honey locust (Gleditsia triacanthos L.), also called sweet-locust or thorny-locust, is a moderately fast growing tree. It is widely planted for windbreaks and soil erosion control and largely recommended like food o...Honey locust (Gleditsia triacanthos L.), also called sweet-locust or thorny-locust, is a moderately fast growing tree. It is widely planted for windbreaks and soil erosion control and largely recommended like food of cattle since it can provide a source of fodder, protein and metabolic energy. Its flowers are incredibly attractive for pollinating insects and thus, form a source of pollen and nectar for honey. This tree was introduced in Europe in 1700 and was introduced by the colonists into Algeria in 1949. In order to valorize the natural substances of this species, the evaluation of the composition of its fruits (pods and seeds separately) in polyphenols, condensed tannins and hydrolysable tannins, which considered as anti-nutritional substances has been done. The obtained results showed that the fruits of Gleditsia triacanthos L. contain very low values in anti-nutritional factors with (0.13%-0.03%) of condensed tannins, (0.78%-0.45%) of hydrolysable tannins and (0.44%-0.16%) of total phenols for pods and seeds, respectively. It arises that these fruits can be of a great interest for many industries especially for feedstock.展开更多
This paper deals with a study on the effects of Chinese fir, loblolly pine and deciduous oak forests on thenutrient status of soils in northern subtropics of China, adopting the principle of forest ecology in the case...This paper deals with a study on the effects of Chinese fir, loblolly pine and deciduous oak forests on thenutrient status of soils in northern subtropics of China, adopting the principle of forest ecology in the caseof similar climate and soil type. The experimental area was situated in the Xiashu Experimental Centre ofForest, where the soil is yellow-brown soil derived from siliceous slope wash. Sample plots of these 3 standswere established to study the nutrient status in litter, the amount of nutrient uptake by roots, the quantityof nutrient output by percolating water outside the deep layer of soil, and the seasonal dynamics of availablenutrient in surface soil. It was shown that the intensity of nutrient cycling in soil under deciduous oak wasthe highest, and the effect of oak in improving soil fertility was the best. The result of improving soil fertilityby Chinese fir was the most inferior, though the intensity of nutrient cycling under that stand was higherthan that under loblolly pine stand. The influence of loblolly pine on the improvement of soil fertility wasbetter than that of Chinese fir, in spite of its lowest intensity of nutrient cycling.展开更多
The monthly changes in chlorophyll a, phytoplankton abundance and physicochemical parameters at two stations in Boka Kotorska Bay were investigated between 2003-2004. Nutrient salts varied widely, with maximum 3.65 μ...The monthly changes in chlorophyll a, phytoplankton abundance and physicochemical parameters at two stations in Boka Kotorska Bay were investigated between 2003-2004. Nutrient salts varied widely, with maximum 3.65 μmol.L^-1 for nitrates and 0.23 μmol.L^-1 for phosphate. Chlorophyll a concentration ranged from 0.25 to 7.63 mg·m^3 and the highest value was measured in winter period of year. It seems that reason for this is the land-based nutrient input into the coastal area here. According to chlorophyll a, nitrates and phosphates concentrations, the area could be oligomesotrophic to mesotrophic during winter.展开更多
This paper reports on the levels of 8 organochlorine pesticide residues and metabolites in three fish species; Tilapia (Oreochromis leucostictus). Common carp (Cyprinus carpio) and Mirror carp (Cuprinus spectacul...This paper reports on the levels of 8 organochlorine pesticide residues and metabolites in three fish species; Tilapia (Oreochromis leucostictus). Common carp (Cyprinus carpio) and Mirror carp (Cuprinus spectacularlus) from Lake Naivasha, Kenya. p,p'-DDT, p,p'-DDE, p,p'-DDD, heptachlor, heptachlor epoxide, aldrin, dieldrin and methoxychlor were analyzed in fish specimens collected from Lake Naivasha during the months of November - December in 2008. The pesticide concentrations (in ~ag/Kg, wet weight) ranged within 0.42-4.185 p,g/Kg, for Heptachlor, BDL-0.291 Heptachlor epoxide, 0.433-4.733 Aldrin, BDL -0.341 Dieldrin, p,p' DDT, BDL-6.691 p,p' DDE, BDL-27.153 p,p' DDD, and BDL-28.867 methoxychlor. The pesticide residue levels varied widely between and within species. C. spectacularhts showed high pesticide levels followed by C. carpio and O. leueostictus respectively; this was attributed to the trophic position and age/size of fish. The occurrences of the pesticides indicate recent use in the catchment. The mean values and ranges of residues found in fish ware below the FAO/WHO maximum acceptable limits in fish and sea food however increased monitoring is recommended to detect any changes.展开更多
A field experiment was carried out at Abu-Rawash sewage farm to appraise the effect of certain novel remediative amendments on the quality of oil as well as the vegetative parameters and yield criteria of canola plant...A field experiment was carried out at Abu-Rawash sewage farm to appraise the effect of certain novel remediative amendments on the quality of oil as well as the vegetative parameters and yield criteria of canola plant used as hyperaccumulator for the remediation of sewaged soils. The treatments included fallow soil (irrigated without growing canola), soil cultivated with canola (Brassica napus L.) and inoculated with arbuscular mycorrhiza (AM), soil inoculation with Thiobacillus sp. (a mixture of Thiobacillus ferrooxidans and Thiobacillus thiooxidant), soil treated with a mixture of 250 mg bentonite plus 250 mg rock phosphate/kg soil and inoculated with phosphate dissolving bacteria (PDB), and soil treated with all the aforementioned remediative amendments. Results indicated that the vegetative parameters and yield criteria of canola plant did not exhibit any serious adverse impact under all treatments applied. The concentrations of Zn and Cu in canola oil extracted from plants grown in soil inoculated with AM and/or Thiobacillus sp. far exceeded the safe permissible levels. On the other hand, the content of both PTEs in the oil extracted from canola plants grown in soil treated with either probentonite or with mixture of all remediative amendments followed the permissible safe levels.展开更多
Dates are considered as the most important food in the south-west oases of Algeria. The Date Palm (Phoenix dactylifera) has known some kind of specificity in its different life phases, compared to all the rest of oa...Dates are considered as the most important food in the south-west oases of Algeria. The Date Palm (Phoenix dactylifera) has known some kind of specificity in its different life phases, compared to all the rest of oases cultivate plants. It is thanks to that person could settle down. A study within a ministerial research project about the date palm variety in the previous areas has shown that there are 400 spices of dates. Thanks to this diversification types, members of this community were able to acquire experience in the field of the uses of date in their nutritional behaviour. Harvest begins from precocious summer's soft date variety in June, as in the late autumn variety in October. In addition, there are different type of the date: wet, semi-wet and dry date. For each variety, there is a particular method of its use. It is an example of sustainable food, is the one present in all oasis occasions. The aim of the current study was to examine the different methods of nutritional ate uses, in Touat, Gourara and Tidikelt, by its inhabitants, and to show the local skills sustained across the generations.展开更多
Nutrimental requirements of heliophytic poinsettias have not yet been determined, this information is essential for developing an adequate technological package to orient producers in its management. The behavior of t...Nutrimental requirements of heliophytic poinsettias have not yet been determined, this information is essential for developing an adequate technological package to orient producers in its management. The behavior of the plant under nutritional stress needs to be known by the application of a hydroponic system. The objective of the present work was to evaluate the physiological effect of induced deficiencies of five macronutriments (nitrogen, phosphorous, potassium, calcium, and magnesium) and its influence on the pigment production of the poinsettia Euphorbia puleherrima cv. "Valenciana". The study was made during 2010 at the Research Unit "Dr. Ramon Fernandez Gonzalez" in Texcoco, State of Mexico. Six treatments were tested during 240 days from transplant in a totally randomized experimental design. Chlorophylls contents were determined at the beginning of the experiment. At the end of the treatment period, the contents of nutrients, chlorophylls, leaf carotenoids and bract anthocyanins were determined. The effects observed as results of the treatments were: reduction in plant height and diameter; the lowest content of total chlorophylls was observed in the absence of nitrogen, the largest reduction being of chlorophyll a and carotenoids; a low content of anthocyanins was observed to be associated with low nitrogen and calcium; a high correlation was found between nitrogen supplementation and measured non-destructively with a SPAD 502 Minolta unit values measured intensity of green color of leaves.展开更多
The objectives of this research were to record the changes in composition of the community of ephemeroptera in Plalar-Gremeng river, examine the causes of these changes and discover their significance in the life of t...The objectives of this research were to record the changes in composition of the community of ephemeroptera in Plalar-Gremeng river, examine the causes of these changes and discover their significance in the life of the rivers. The ephemeropteran community and abundance of the feeding group (detritivore, gatherer and scrapper) were compared with the nutrient and water quality of each sampling site. It is established that, under site conditions, nutrient status can be regarded as the chief internal factors. The method was field survey for sampling the substrate at five sites: (I) Up-stream of Plalar river; (2) The site before the Plalar cave; (3) The total dark zone of Plalar-Gremeng caves; (4) The site after Gremeng cave and (5) The down-stream of Gremeng to Beton river. Substrate sampling used Surber benthic sampler and the sample was containing and labeling. Environmental parameters were measured water temperature, carbon dioxide, velocity, pH, C-organic, sediment total-phosphorus and nitrogen and Ca content. The data was analyzed by description. The results showed that the abundance of ephemeroptera was highest at site-4 and the lowest at site-3. Ephemeropthera play a highly important role in preserving nutrient status.展开更多
This paper presents some problems related to water quality and the condition of lakes in Romania, as well as methods for improving the quantity of oxygen dissolved in water. A method for water aeration and the install...This paper presents some problems related to water quality and the condition of lakes in Romania, as well as methods for improving the quantity of oxygen dissolved in water. A method for water aeration and the installation used to implement it are described and the associated advantages regarding the reduction in the level of eutrophication are highlighted. The hydraulic installation for improving the quality of water from lakes, basins, reservoirs or slow flowing rivers was designed and tested in our hydraulics laboratory during a research project. It is floatable, environmentally friendly, and energetically autonomous, being powered by photovoltaic panels, which together with rechargeable batteries can assure a continuous operation. This installation could also be used in early stages of wastewater treatment. Experimental results regarding the performance curves of the hydraulic installation are also presented.展开更多
基金Project supported by the National Natural Science Foundation of China (Nos. 30471378, 90202010 and 30211130504)the Applied and Basic Research Program of Sichuan Province, and the Talent-Recruiting Program of Sichuan Agricultural University
文摘Macronutrients (N, P, K, Ca, Mg, and S) in litter of three primarily spruce (Picea purpurea Masters) (SF), fir (Abies faxoniana Rehder & E. H. Wilson) (FF), and birch (Betula platyphylla Sukaczev) (BF) subalpine forests in western China were measured to understand the monthly variations in litter nutrient concentrations and annual and monthly nutrient returns via litteffall. Nutrient concentration in litter showed the rank order of Ca 〉 N 〉 Mg 〉 K 〉 S 〉 P. Monthly variations in nutrient concentrations were greater in leaf litter (LL) than other litter components. The highest and lowest concentrations of N, P, K, and S in LL were found in the growing season and the nongrowing season, respectively, but Ca and Mg were the opposite. Nutrient returns via litterfall showed a marked monthly pattern with a major peak in October and one or two small peaks in February and/or May, varying with the element and stand type, but no marked monthly variations in nutrient returns via woody litter, reproductive litter, except in May for the BF, and moss litter. Not only litter production but also nutrient concentration controlled the annual nutrient return and the monthly nutrient return pattern. The monthly patterns of the nutrient concentration and return were of ecological importance for nutrient cycling and plant growth in the subalpine forest ecosystems.
基金Project(No.30170770)supported by the National Natural Science Foundation of China.Corresponding author.Tel:0599-8504990Fax:0599-8516481E-mail:ffcyys@public.npptt.fj.cn.
文摘A Chinese fir forest (Cunninghamia lanceolata, CF) and an evergreen broadleaved forest (EB) located inFujian Province, southeastern China, were examined following slash burning to compare nutrient capital andtopsoil properties with pre-burn levels. After fire, nutrient (N, P and K) removal from burning residues wasestimated at 302.5 kg ha-1 in the CF and 644.8 kg ha-1 in the EB. Fire reduced the topsoil capitals of totalN and P by about 20% and 10%, respectively, in both forests, while K capital was increased in the topsoils ofboth forests following fire. Total site nutrient loss through surface erosion was 28.4 kg (N) ha-1, 8.4 kg (P)ha-1 and 328.7 kg (K) ha-1 in the CF. In the EB, the losses of total N, P and K were 58.5, 10.5 and 396.3kg ha-1, respectively. Improvement of soil structure and increase in mineralization of nutrients associatedwith increased microbe number and enzyme activities and elevated soil respiration occurred 5 days after fire.However, organic matter and available nutrient contents and most of other soil parameters declined one yearafter fire on the burned CF and EB topsoils. These results suggest that short-term site productivity canbe stimulated immediately, but reduced subsequently by soil and water losses, especially in South China,where high-intensity precipitation, steep slopes and fragile soil can be expected. Therefore, the silviculturalmeasurements should be developed in plantation management.
文摘Four species of African giant land snails (Archachatina marginata (ovum ) Pfeiffer, Archachatina marginata (saturalis ) Philippi, Achatina achatina and Limicolaria spp.) were assessed for their proximate and mineral compositions aimed at establishing their nutritive values on wet weight basis. Analysis of muscle revealed that composition of crude protein varied from 18.66%±0.57% in Limicolaria spp. and 20.56%±L0.05% in Archachatina marginata (ovum) Pfeiffer; moisture content was 76.56%±0.04% in Archachatina marginata (ovum) Pfeiffer and 78.68%±0.68% in Limicolaria spp. and ash was 1.34%±0.02% in Achatina achatina and 1.44%±0.01% in Archachatina marginata (ovum) Pfeiffer. These values were statistically different from each other (P〈0.05). Carbohydrate and fat content were generally low. Crude fibre was not detected in any of the species. The concentrations of zinc, iron, manganese, magnesium, calcium, phosphorus, sulphur, potassium and sodium in the flesh of the snails were determined. Values of iron, magnesium, calcium, phosphorus, potassium and sodium were consistently high while cobalt, copper and lead were not detected. Snails complement the required trace and minor elements needed for proper growth and development in human being, so it is recommended for regular consumption.
文摘Inadequate quality and quantity diet is one of the major reasons for high levels of malnutrition in pregnant women. A cross-sectional survey was conducted in Wondo Genet District, Southern Ethiopia. A two-stage cluster sampling technique was used to select a representative sample of 153 pregnant women aged 19-49 years from three rural villages ("Kebeles"). Energy and nutrient intakes from foods were calculated from one-day weighed food records on a sub-sample (n = 77). The result of the study showed that the intakes of most nutrients were lower than the recommended intake. The energy intake of the study participants both in 2nd and 3rd trimesters of pregnancy were 2,308 kcal and 1,420.5 kcal compared to the recommended 2,340 kcal and 2,452 kcal, respectively. Except iron, almost all micronutrient intakes were lower than the recommended intake. Vitamin A intake was 3/ag compared with the recommended 800μg, while protein intake of the study respondents in 2nd and 3rd trimester of pregnancy was 45.9 g and 31.5 g, respectively, compared with the recommended 71 g. Risk factors for undernutrition were multiple pregnancy and no consumption of cereal-based foods. This study revealed that the energy and nutrient intake of the pregnant women in study area was below the recommended intakes. Furthermore, the situation might be aggravated by high phytate content food consumption reported. Nutritional status of pregnant women in study area was not adequate to support the increased energy and nutrient requirement of the participants.
文摘Iron is a critical micronutrient, and iron derived from heme contributes a large proportion of the total iron absorbed in a typical Western diet. Heme iron is absorbed by different mechanisms than non-heme iron, but despite considerable study over many years these mechanisms remain poorly understood. This review provides an overview of the importance of heme iron in the diet and discusses the two prevailing hypotheses of heme absorption; namely receptor mediated endocytosis of heme, and direct transport into the intestinal enterocyte by recently discovered heme transporters. A specific emphasis is placed on the questions surrounding the site of heme catabolism and the identity of the enzyme that performs this task. Additionally, we present the hypothesis that a non-heme iron transport protein may be required for heme iron absorption and discuss the experiences of our laboratory in examining this hypothesis.
文摘Honey locust (Gleditsia triacanthos L.), also called sweet-locust or thorny-locust, is a moderately fast growing tree. It is widely planted for windbreaks and soil erosion control and largely recommended like food of cattle since it can provide a source of fodder, protein and metabolic energy. Its flowers are incredibly attractive for pollinating insects and thus, form a source of pollen and nectar for honey. This tree was introduced in Europe in 1700 and was introduced by the colonists into Algeria in 1949. In order to valorize the natural substances of this species, the evaluation of the composition of its fruits (pods and seeds separately) in polyphenols, condensed tannins and hydrolysable tannins, which considered as anti-nutritional substances has been done. The obtained results showed that the fruits of Gleditsia triacanthos L. contain very low values in anti-nutritional factors with (0.13%-0.03%) of condensed tannins, (0.78%-0.45%) of hydrolysable tannins and (0.44%-0.16%) of total phenols for pods and seeds, respectively. It arises that these fruits can be of a great interest for many industries especially for feedstock.
文摘This paper deals with a study on the effects of Chinese fir, loblolly pine and deciduous oak forests on thenutrient status of soils in northern subtropics of China, adopting the principle of forest ecology in the caseof similar climate and soil type. The experimental area was situated in the Xiashu Experimental Centre ofForest, where the soil is yellow-brown soil derived from siliceous slope wash. Sample plots of these 3 standswere established to study the nutrient status in litter, the amount of nutrient uptake by roots, the quantityof nutrient output by percolating water outside the deep layer of soil, and the seasonal dynamics of availablenutrient in surface soil. It was shown that the intensity of nutrient cycling in soil under deciduous oak wasthe highest, and the effect of oak in improving soil fertility was the best. The result of improving soil fertilityby Chinese fir was the most inferior, though the intensity of nutrient cycling under that stand was higherthan that under loblolly pine stand. The influence of loblolly pine on the improvement of soil fertility wasbetter than that of Chinese fir, in spite of its lowest intensity of nutrient cycling.
文摘The monthly changes in chlorophyll a, phytoplankton abundance and physicochemical parameters at two stations in Boka Kotorska Bay were investigated between 2003-2004. Nutrient salts varied widely, with maximum 3.65 μmol.L^-1 for nitrates and 0.23 μmol.L^-1 for phosphate. Chlorophyll a concentration ranged from 0.25 to 7.63 mg·m^3 and the highest value was measured in winter period of year. It seems that reason for this is the land-based nutrient input into the coastal area here. According to chlorophyll a, nitrates and phosphates concentrations, the area could be oligomesotrophic to mesotrophic during winter.
文摘This paper reports on the levels of 8 organochlorine pesticide residues and metabolites in three fish species; Tilapia (Oreochromis leucostictus). Common carp (Cyprinus carpio) and Mirror carp (Cuprinus spectacularlus) from Lake Naivasha, Kenya. p,p'-DDT, p,p'-DDE, p,p'-DDD, heptachlor, heptachlor epoxide, aldrin, dieldrin and methoxychlor were analyzed in fish specimens collected from Lake Naivasha during the months of November - December in 2008. The pesticide concentrations (in ~ag/Kg, wet weight) ranged within 0.42-4.185 p,g/Kg, for Heptachlor, BDL-0.291 Heptachlor epoxide, 0.433-4.733 Aldrin, BDL -0.341 Dieldrin, p,p' DDT, BDL-6.691 p,p' DDE, BDL-27.153 p,p' DDD, and BDL-28.867 methoxychlor. The pesticide residue levels varied widely between and within species. C. spectacularhts showed high pesticide levels followed by C. carpio and O. leueostictus respectively; this was attributed to the trophic position and age/size of fish. The occurrences of the pesticides indicate recent use in the catchment. The mean values and ranges of residues found in fish ware below the FAO/WHO maximum acceptable limits in fish and sea food however increased monitoring is recommended to detect any changes.
文摘A field experiment was carried out at Abu-Rawash sewage farm to appraise the effect of certain novel remediative amendments on the quality of oil as well as the vegetative parameters and yield criteria of canola plant used as hyperaccumulator for the remediation of sewaged soils. The treatments included fallow soil (irrigated without growing canola), soil cultivated with canola (Brassica napus L.) and inoculated with arbuscular mycorrhiza (AM), soil inoculation with Thiobacillus sp. (a mixture of Thiobacillus ferrooxidans and Thiobacillus thiooxidant), soil treated with a mixture of 250 mg bentonite plus 250 mg rock phosphate/kg soil and inoculated with phosphate dissolving bacteria (PDB), and soil treated with all the aforementioned remediative amendments. Results indicated that the vegetative parameters and yield criteria of canola plant did not exhibit any serious adverse impact under all treatments applied. The concentrations of Zn and Cu in canola oil extracted from plants grown in soil inoculated with AM and/or Thiobacillus sp. far exceeded the safe permissible levels. On the other hand, the content of both PTEs in the oil extracted from canola plants grown in soil treated with either probentonite or with mixture of all remediative amendments followed the permissible safe levels.
文摘Dates are considered as the most important food in the south-west oases of Algeria. The Date Palm (Phoenix dactylifera) has known some kind of specificity in its different life phases, compared to all the rest of oases cultivate plants. It is thanks to that person could settle down. A study within a ministerial research project about the date palm variety in the previous areas has shown that there are 400 spices of dates. Thanks to this diversification types, members of this community were able to acquire experience in the field of the uses of date in their nutritional behaviour. Harvest begins from precocious summer's soft date variety in June, as in the late autumn variety in October. In addition, there are different type of the date: wet, semi-wet and dry date. For each variety, there is a particular method of its use. It is an example of sustainable food, is the one present in all oasis occasions. The aim of the current study was to examine the different methods of nutritional ate uses, in Touat, Gourara and Tidikelt, by its inhabitants, and to show the local skills sustained across the generations.
文摘Nutrimental requirements of heliophytic poinsettias have not yet been determined, this information is essential for developing an adequate technological package to orient producers in its management. The behavior of the plant under nutritional stress needs to be known by the application of a hydroponic system. The objective of the present work was to evaluate the physiological effect of induced deficiencies of five macronutriments (nitrogen, phosphorous, potassium, calcium, and magnesium) and its influence on the pigment production of the poinsettia Euphorbia puleherrima cv. "Valenciana". The study was made during 2010 at the Research Unit "Dr. Ramon Fernandez Gonzalez" in Texcoco, State of Mexico. Six treatments were tested during 240 days from transplant in a totally randomized experimental design. Chlorophylls contents were determined at the beginning of the experiment. At the end of the treatment period, the contents of nutrients, chlorophylls, leaf carotenoids and bract anthocyanins were determined. The effects observed as results of the treatments were: reduction in plant height and diameter; the lowest content of total chlorophylls was observed in the absence of nitrogen, the largest reduction being of chlorophyll a and carotenoids; a low content of anthocyanins was observed to be associated with low nitrogen and calcium; a high correlation was found between nitrogen supplementation and measured non-destructively with a SPAD 502 Minolta unit values measured intensity of green color of leaves.
文摘The objectives of this research were to record the changes in composition of the community of ephemeroptera in Plalar-Gremeng river, examine the causes of these changes and discover their significance in the life of the rivers. The ephemeropteran community and abundance of the feeding group (detritivore, gatherer and scrapper) were compared with the nutrient and water quality of each sampling site. It is established that, under site conditions, nutrient status can be regarded as the chief internal factors. The method was field survey for sampling the substrate at five sites: (I) Up-stream of Plalar river; (2) The site before the Plalar cave; (3) The total dark zone of Plalar-Gremeng caves; (4) The site after Gremeng cave and (5) The down-stream of Gremeng to Beton river. Substrate sampling used Surber benthic sampler and the sample was containing and labeling. Environmental parameters were measured water temperature, carbon dioxide, velocity, pH, C-organic, sediment total-phosphorus and nitrogen and Ca content. The data was analyzed by description. The results showed that the abundance of ephemeroptera was highest at site-4 and the lowest at site-3. Ephemeropthera play a highly important role in preserving nutrient status.
文摘This paper presents some problems related to water quality and the condition of lakes in Romania, as well as methods for improving the quantity of oxygen dissolved in water. A method for water aeration and the installation used to implement it are described and the associated advantages regarding the reduction in the level of eutrophication are highlighted. The hydraulic installation for improving the quality of water from lakes, basins, reservoirs or slow flowing rivers was designed and tested in our hydraulics laboratory during a research project. It is floatable, environmentally friendly, and energetically autonomous, being powered by photovoltaic panels, which together with rechargeable batteries can assure a continuous operation. This installation could also be used in early stages of wastewater treatment. Experimental results regarding the performance curves of the hydraulic installation are also presented.