排序方式： 共有14条查询结果，搜索用时 31 毫秒
1.
Discrimination of lithogenic and anthropogenic influences on topsoil magnetic susceptibility in Central Europe 总被引：12，自引：0，他引：12
T. Magiera Z. Strzyszcz A. Kapicka E. Petrovsky EU RTD Project No. EVK-CT-- MAGPROX TEAM 《Geoderma》2006,130(3-4):299-311
The study was performed on the area of the three countries involved in the MAGPROX project (Poland, Czech Rep., Germany). In the first stage the basic map of magnetic susceptibility based on the field topsoil measurement was compiled with an average grid density of 10 km. In the second stage of the study, vertical distribution of magnetic susceptibility of ca. 600 topsoil cores (0.3 m long), collected over central Europe, was examined with respect to the anthropogenic or lithogenic influence on magnetic susceptibility of the soil surface, with the focus being on the interpretation of the areas showing high surface susceptibility values. The maximum values were mostly observed in depths of 3–4 cm. In general seven different types of susceptibility profiles from forest areas and one typical for urban soil are presented. They are a result of a combination of natural (litho- and pedogenic) and anthropogenic contributions. Our results prove that soil profiles, dominated by anthropogenic influence due to atmospherically deposited dust, are characterized by magnetically enhanced humuous layer, corresponding to layer with the highest concentration of heavy metals. Moreover, forest soils show in these cases higher magnetic susceptibility than soils in open areas (grassland, meadows or arable soils). 相似文献
2.
Agiang MA Umoh IB Essien AI Eteng MU 《Pakistan journal of biological sciences: PJBS》2010,13(20):1011-1015
Evaluations of the effect of prolong cooking on the nutrient and antinutrient composition ofbeniseed and beniseed soup were carried out in this study. Proximate, mineral, vitamin A and C and antinutrient compositions of raw beniseed (BS-R), beniseed boiled (BSB) for 15, 30, 45 and 60 min and beniseed soup (BSS) cooked for the same intervals of time were assessed. Results of the proximate composition analyses showed that raw and boiled beniseed had lower moisture content (5.39-5.51%) than beniseed soups (10.06-15.20%). Nitrogen-free extract (total carbohydrates), fats and phosphorus contents were improved in both the boiled beniseed and beniseed soup while calcium and potassium were increased in the boiled seeds and soup samples respectively. Moisture (in the raw and boiled beniseed), ash, magnesium, zinc, iron contents in both the seed and soup were unchanged in all the samples. Vitamins A and C levels of both boiled beniseed and beniseed soup samples were reduced with increase in cooking time. Beniseed soup had higher protein contents than both the raw and boiled beniseed which decreased with increase in cooking time. Beniseed samples provided good sources of energy (572.97-666.05 kcal/100 g). Except for phytate, the levels of antinutrients tested were lower in the raw and boiled beniseed than in the soup samples which decreased with increase in cooking time. The results are discussed with reference to the effect of prolonged cooking on the nutrient requirements of consumers. 相似文献
3.
The winter wheat seeds (of three varieties namely Batko, Diya and Krasnodar 99) were germinated and investigated for the effect of growth regulator, Furolan on the pigment, IAA and total nitrogen and protein contents of their germinal leaves. Results showed differences in pigment contents of the germinal leaves of winter wheat varieties studied. Furolan increased the contents of chlorophyll a in all the varieties studied by the range of 22.7–26.4%. The amount of chlorophyll b in Diya’s variety increased by 22.2% while the amount of contents of carotenoids in Batko variety increased by 43.5% in comparison with the control. The highest amount of chlorophyll a and b was recorded in Batko and the least in Diya variety. The reverse was the case with the carotenoids: Furolan increased the amount of carotenoids in all the varieties; the highest amount of carotenoids was observed in Diya variety and Batko variety recorded the least amount In all the varieties studied the Furolan increased the IAA, total nitrogen and protein contents in comparison to the control. 相似文献
4.
Essien Okon 《Russian Agricultural Sciences》2012,38(4):265-268
This study was carried out to investigate the effect of storage time and growth regulator, Furolan on protein, non-protein nitrogen and nitrogen contents of three varieties of winter wheat grains namely Batko, Diya and Krasnodar 99. The contents of the nitrogen, protein and non-protein nitrogen in winter wheat grain were determined by different protocols during the full ripeness phase of the grain and the period of 12 months storage. The grains (both the control and experimental) were kept in storage for varied periods under normal conditions. Krasnodar 99 variety responded most to the Furolan and recorded an increase in protein nitrogen content by 46.3% followed by 24.9% in experimental Batko variety and 17.4% in Diya??s variety in comparison with the control. The content of protein nitrogen in the grain of experimental Batko variety increased up to the seventh month of storage, and then decreased by the 12th month of storage. In the control??a similar tendency of change in this parameter was observed. It was noted that seven months of storage is critical in change dynamics of the content of non-protein nitrogen in the selected winter wheat varieties studied. 相似文献
5.
The concentrations and distribution of selected heavy metals in epipelic and benthic sediments of Cross River Estuary mangrove swamp were studied to determine the extent of anthropogenic inputs from industrial activities and to estimate the effects of seasonal variations on geochemical processes in this tropical estuarine ecosystem. The analysis shows that the mean concentrations (mg/kg, dw) of Cu, Cr, Fe, Ni, Pb, V and Zn vary from 24.1–32.4, 19.9–27.4, 666.7–943.5, 15.2–30.3, 8.8–24.7, 2.2–6.9 and 140.1–188.9, respectively. An important observation is that, in general, lowest metal concentrations are found during the dry season, compared to wet season. Pollution load index (PLI) and index of geoaccumulation (I geo) revealed overall low values but the enrichment factors (EFs) for Cr, Zn, and V were high, and this reflects the intensity of anthropogenic inputs related to industrial discharge into the estuary. The mean concentrations of Zn, Cu and to some extent Ni exceeded the Effects Range—Low (ERL) and Threshold Effect Level (TEL) values in majority of the samples studied, indicating that there may be some ecotoxicological risk to organisms living in these sediments. The inter-element relationship revealed the identical source of elements in the sediments of the studied area. The concentration of heavy metals reported in this work will be useful as baselines for comparison in future sediment quality studies. 相似文献
6.
The effect of Mangifera indica stem bark and Pluchea ovalis roots on tracheal smooth muscle in vitro 总被引：2，自引：0，他引：2
Agbonon A Eklu-Gadegbeku K Aklikokou K Essien K Akpagana K Gbeassor M 《Fitoterapia》2002,73(7-8):619-622
Aqueous extract of the stem bark of Mangifera indica and ethanolic extract of the roots of Pluchea ovalis has been studied on rat tracheal smooth muscle in vitro. The extract of M. indica at 1, 2 and 4 mg/ml and that of P. ovalis at 0.25, 0.5 and 1 mg/ml relaxed, dose-dependently, the rat tracheal smooth muscle strip previously contracted by acetylcholine at 0.055 mmol/l. 相似文献
7.
E. U. Isong I. B. Essien 《Plant foods for human nutrition (Dordrecht, Netherlands)》1996,49(2):133-137
The proximate composition of three varieties ofPiper guineense (Odusa — Ibibio/Efik) viz. Uyat Odusa (cultivated and peppery), Eting-keni Ikot (wild forest variety) and Eting-keni mben inyang (wild, riverine variety), were determined using available standard methods. Also determined were mineral, antinutrient and ascorbate levels. The cultivated pepperic variety had the highest content of crude protein and moisture (18.9% and 97% respectively) while the wild, riverine variety had the highest content of ether extract, carbohydrate and calories (7.79%, 63.38% and 398 cals respectively). The cultivated variety had appreciable amounts of phosphorus (1.12 mg/100 g), potassium (1.2 mg/100 g), sodium (0.24 mg/100 g), zinc (0.18 mg/100 g), and copper (0.18 mg/100 g) while the forest variety contained more of calcium (12.38 mg/100 g), magnesium (1.21 mg/100 g) and iron (0.85 mg/100 g). The wild riverine variety appeared to have the least mineral content but had the highest ascorbate level of 173.4 mg/100 g. Of four antinutrients assayed, the cultivated pepperic one had the least quantities while the forest variety was highest in hydrocyanic acid (85.8 mg/100 g) and glucosinolates (0.20 mg/100 g). The wild riverine variety had the highest level of total oxalate (165.0 mg/100 g). These quantities are however far below documented toxic levels. 相似文献
8.
E. U. Essien G. J. Esenowo M. I. Akpanabiatu 《Plant foods for human nutrition (Dordrecht, Netherlands)》1995,48(2):135-140
The lipid content and fatty acid profiles of four lesser known tropical seeds,Piper guineense, Chrysophyllum albidum, Garcinia kola andDennettia tripetala, were determined. The total lipid content (g/kg dry weight) ranged between 31.8 and 68.9. The ranges of values for neutral lipids, triacylglycerol of neutral lipids, glycolipids and phospholipids were 17.3–58.0, 15.0–49.6, 3.0–7.2 and 3.7–11.2, respectively. The fatty acid profiles showed variation among different seeds. All the seeds contained substantial amounts of unsaturated fatty acids. Oleic and linoleic acids were the most abundant fatty acids.Dennettia tripetala andPiper guineense also contained moderate amounts of linolenic acid. 相似文献
9.
Charles Essien Brian K. Via Gifty Acquah Thomas Gallagher Timothy McDonald Lori Eckhardt 《林业研究》2018,29(6):1519-1531
Tree improvement programs on loblolly pine (Pinus taeda) in the southeastern USA has focused primarily on improving growth, form, and disease tolerance. However, due to the recent reduction of design values for visually graded southern yellow pine lumber (including loblolly pine), attention has been drawn to the material quality of genetically improved loblolly pine. In this study, we used the time-of-flight (TOF) acoustic tool to assess the effect of genetic families on diameter, slenderness, fiber length, microfibril angle (MFA), velocity and dynamic stiffness estimated using green density (DMOEG) and basic density (DMOEB) of 14-year-old loblolly pine stands selected from two sites. All the 184 and 204 trees of the selected eight half-sib genetic families on sites 1 and 2 respectively were tested using TOF acoustic tool, and two 5 mm core samples taken at breast height level (1.3 m) used to for the anatomical and physical properties analysis. The results indicated a significant positive linear relationship between dynamic MOEs (DMOEG and DMOEB) versus tree diameter, slenderness, and fiber length while dynamic MOEs negatively but nonsignificant correlated with MFA. While there was no significant difference in DMOEB between sites; velocity2 for site 1 was significantly higher than site 2 but DMOEG was higher for site 2 than site 1. Again, the mean DMOEG and DMOEB reported in the present study presents a snapshot of the expected static MOE for green and 12% moisture conditions respectively for loblolly pine. Furthermore, there were significant differences between families for most of the traits measured and this suggests that forest managers have the opportunity to select families that exhibit the desired fiber morphology for final product performance. Lastly, since the dynamic MOE based on green density (DMOEG), basic density (DMOEB) and velocity2 present difference conclusions, practitioners of this type of acoustic technique should take care when extrapolating results across the sites. 相似文献
10.
Essien Okon Hannah Edim Etta Vladimir Zuba Arikpo Ikpi Okoi 《Russian Agricultural Sciences》2016,42(1):17-25
Genetical and biometrical analyses were carried out to investigate the variation of grain sizes in three winter varieties (namely Batko, Diya and Krasnodarskaya 99) under the influence of the growth regulator, Furolan and mineral fertilizer. The 1000–grain weight trait was equally analyzed. The difference in germination energy of large seeds between extreme variants amounted 6.0% (LSD05-var. = 2.85). There were significant differences in germination energy of seeds. Extreme variants differed significantly among themselves in laboratory germinating power of seeds. The difference between them was 4.0% (LSD05-var. = 1.84). The variant treated with growth regulator, Furolan did not differ significantly from control. Mineral fertilizers in Bat’ko variety increased laboratory germinating power of seeds; its increase in comparison with control was 2.0% (LSD05-var. = 1.84). The difference between experimental variants in 1000–grain weight of small grains was 0.6 g (LSD05-fact. C = 0.13) which showed that Furolan significantly increased 1000–grain weight of most of the winter wheat varieties studied. 相似文献