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31.
Lars A. Knechtenhofer Irene O. Xifra Andreas C. Scheinost Hannes Flühler Ruben Kretzschmar 《植物养料与土壤学杂志》2003,166(1):84-92
To assess the mobility of Pb and associated metals in a highly contaminated shooting range soil (Losone, Ticino, Switzerland), we investigated the spatial distribution of the metals and their relation to preferential water flow paths. A 2.2 m2 plot located 40 m behind the stop butt was irrigated with a solution containing bromide and Brilliant Blue, a slightly sorbing dye. A soil profile 50 cm in width was sampled down to 80 cm with a spatial resolution of 2.5 cm, resulting in 626 samples. Concentrations of elements (12 ≤ Z ≤ 92) were determined by energy‐dispersive Xray fluorescence spectrometry, and Brilliant Blue concentrations were determined with a chromameter. In the acidic (pH 3), organic matter‐rich, well drained Dystric Cambisol, maximum concentrations of 80.9 g kg‐1 Pb, 4.0 g kg‐1 Sb, and 0.55 g kg‐1 Cu were measured in the topsoil. Within 40 cm soil depth, however, Pb, Sb, and Cu approached background concentrations of 23 mg kg‐1, 0.4 mg kg‐1, and 9.4 mg kg‐1, respectively. The even horizontal distribution and the steep gradient along soil depth indicate tight metal binding in the topsoil, and a fairly homogeneous transport front. In contrast, water flow through the profile was highly heterogeneous. In the uppermost 20 cm, preferential flow was initiated by heterogeneous infiltration at the soil surface, but had no influence on metal distribution. Below 20 cm, however, preferential flow originated from larger tree roots, and metal concentrations were significantly elevated along these macropores. Spatial distributions of Pb, Sb, and Cu were similar, suggesting that all three metals are strongly retained in the topsoil and transported along preferential water flow paths in the subsoil. 相似文献
32.
Jann Th. Martinsohn Paul Raymond Trey Knott Kevin A. Glover Einar Eg Nielsen Lars Bonde Eriksen Rob Ogden John Casey Jordi Guillen 《Fish and Fisheries》2019,20(2):391-401
Evidence from DNA‐analysis is commonplace in human criminal investigations, and while it is increasingly being used in wildlife crime, to date, its application to control and enforcement activities in fisheries and aquaculture has only been sporadic. Contemporary DNA‐analysis tools are capable of addressing a broad range of compliance issues, species identification, mislabelling of fish products, determining the origin of catches and the farm of origin of aquaculture escapees. Such applications have the potential to ensure traceability along the fish product supply chain and to combat consumer fraud and Illegal, Unreported and Unregulated fishing. Nevertheless, DNA‐analysis is not yet used routinely in investigations into compliance with fisheries and aquaculture legislation. One potential reason for this is that DNA‐analysis techniques may have been regarded as too expensive. However, costs have plummeted over the past decade prompting us to objectively assess whether the costs associated with routine use of DNA‐analysis techniques for fisheries and aquaculture control and enforcement activities do constitute an impediment. Based on a number of recent fisheries and aquaculture compliance investigations that incorporated DNA‐analysis, our results indicate that the use of genetic analysis was justified and worthwhile in all cases examined. We therefore conclude that the costs associated with DNA‐analysis do not represent a barrier to the routine adoption of DNA‐analysis techniques in fisheries and aquaculture compliance investigations. Thus, control and enforcement agencies should be encouraged to use such techniques routinely. 相似文献
33.
Calves with experimentally induced iron deficiency anemia and normal calves, both groups deprived of colostrum, were exposed to intranasal instillation of an attenuated parainfluenza-3 virus strain.The calves became infected, but there was no difference in the clinical picture between the 2 groups of calves. Neither was there a difference in the humoral or local immune response to parainfluenza-3 virus. 相似文献
34.
From 1996 to 2001 a total of 467 Staphylococcus hyicus isolates from exudative epidermitis (EE) in pigs in Denmark were examined for susceptibility to 13 different antimicrobial agents. The presence of selected genes encoding macrolide (erm(A), erm(B) and erm(C)), penicillin (blaZ), streptogramin (vat, vga, vga(B), vat(B), vat(D) and vat(E)), streptomycin (aadE) and tetracycline resistance (tet(K), tet(L), tet(M) and tet(O)) were determined in selected isolates.The occurrence of erythromycin resistance increased from 33% in 1996 to a maximum of 62% in 1997 and decreased to 26% in 2001. Resistance to sulphametazole increased from 17% in 1996 to 30% in 1998 but has since decreased to 4% in 2001. Resistance to trimethoprim increased to 51% in 1997 and decreased to 21% in 2001. Resistance to tetracycline (21-31%) remained relatively constant during 1996-2000, but increased to 47% in 2001. Resistance to penicillin (54-75%) streptomycin (33-53%) and tetracycline (21-47%) remained relatively constant over the time investigated.All 48 penicillin resistant isolates examined contained the blaZ gene and 40 (85%) of the streptomycin resistant isolates the aadE gene. It was not possible to detect any streptogramin resistance gene in four streptogramin resistant isolates. Of the 55 erythromycin resistant isolates examined, five contained erm(A), 13 erm(B), 35 erm(C) and two both erm(A) and erm(C). The presence of erm(B) was confirmed by hybridization to plasmid profiles in all 13 PCR-positive isolates. Of 52 tetracycline resistant isolates examined, two contained tet(L), 38 tet(K) and 12 both tet(K) and tet(L). 相似文献
35.
36.
This article discusses the determinants of profitability expressed as return on capital among Japanese pulp and paper companies. Return on capital is measured as income before tax related to stockholders’ equity. Return on capital has been divided into profit margin and asset utilization rate. The hypothesis is that return on capital can be explained by mill size, productivity, product line, financial situation, and use of wood resources. The dataset consists of 13 larger Japanese pulp and paper companies listed in Pulp &; Paper Statistics. Data on financial performance, production, and use of wood fibers were collected for the period 1991–2001. The average return on equity for the studied companies is 4.2%. Labor productivity has increased quite significantly, from about 600 to 1,000 kg/employee and year. An econometric analysis indicates that the best model fit is found when the asset utilization rate is used as the dependent variable. Significant variables are, among others, asset utilization rate lagged one time period (?), labor productivity (+), capital productivity (?), paper production as a share of total paper and board production (?), total value of assets on the books (?) and solidity (+). This may indicate that the total value of assets on the books is large in relation to the total production of paper, paperboard and pulp. 相似文献
37.
38.
Young JF Duthie SJ Milne L Christensen LP Duthie GG Bestwick CS 《Journal of agricultural and food chemistry》2007,55(3):618-623
The polyacetylene falcarinol, isolated from carrots, has been shown to be protective against chemically induced colon cancer development in rats, but the mechanisms are not fully understood. In this study CaCo-2 cells were exposed to falcarinol (0.5-100 microM) and the effects on proliferation, DNA damage, and apoptosis investigated. Low-dose falcarinol exposure (0.5-10 microM) decreased expression of the apoptosis indicator caspase-3 concomitantly with decreased basal DNA strand breakage. Cell proliferation was increased (1-10 microM), whereas cellular attachment was unaffected by <10 microM falcarinol. At concentrations above 20 microM falcarinol, proliferation of CaCo-2 cells decreased and the number of cells expressing active caspase-3 increased simultaneously with increased cell detachment. Furthermore, DNA single-strand breakage was significantly increased at concentrations above 10 microM falcarinol. Thus, the effects of falcarinol on CaCo-2 cells appear to be biphasic, inducing pro-proliferative and apoptotic characteristics at low and high concentrations of falcarinol, respectively. 相似文献
39.
Lien L 《Public health nutrition》2007,10(4):422-428
OBJECTIVE: To examine the relationship between mental distress, academic performance and regular breakfast consumption across gender and immigration status. DESIGN: Cross-sectional population-based study. Two four-page questionnaires were filled in during two school sessions. SETTING: All junior high schools in Oslo, Norway using the classroom as the setting for the study. SUBJECTS: All 10th grade students 15-16 years olds in 2000 and 2001. Of 8316 eligible students, 7343 (88.3%) participated in the study. RESULTS: All immigrant groups, except the Western countries group, are skipping breakfast more often than Norwegian students, and girls more often than boys (27 versus 19%). After adjustment for possible confounding factors, the odds ratio (OR) for being mentally distressed when eating breakfast seldom/never compared with every day was 3.0 (2.0-4.5) for boys, 1.6 (1.2-2.1) for girls and 1.6 (1.5-2.6) for the immigrant group. The comparable OR for having low school grades was similar for boys and girls, 2.0 (1.3-3.0), and 1.6 (1.5-2.6) for the immigrant groups. CONCLUSIONS: Skipping breakfast is a common feature among 10th grade students. The implications of skipping breakfast on mental distress and academic performance are stronger for boys than girls and stronger for Norwegians compared with immigrants. 相似文献
40.
Julie Therese Christensen Musibau Oyeleke Azeez Rodrigo Labouriau Sabine Ravnskov Hanne Lakkenborg Kristensen Lars Juhl Munkholm Gitte Holton Rubæk 《Soil Use and Management》2022,38(1):991-1003
Lime and phosphorus (P) applications are common agricultural management practices. Our aim was to quantify the effects of long-term application practices on root growth and abundance of arbuscular mycorrhizal fungi (AMF) under field conditions. We assessed the effects of lime and P fertilizer applications on barley yield, root growth and AMF abundance in 2016. Treatments were no, low, medium and high liming rate corresponding to application of 0, 4, 8 and 12 Mg lime ha−1 every 5–9 years since 1942 combined with no or yearly application of 15.6 kg P ha−1 since 1944. At harvest, grain yield, root intensity (core-break) and AMF abundance at different soil depths were estimated. Root development was monitored during early growth with minirhizotrons in treatments receiving low, medium and high liming rates and P fertilization. A quadratic model relating grain yield to liming rate estimated yields to peak at 6.4 Mg lime ha−1 with yields of 4.2 and 3.2 Mg grain ha−1 with and without P fertilization, respectively. Low and medium liming rates resulted in greater AMF abundance, especially in the no P treatments. During early growth in P-fertilized treatments, 77% and 65% more roots developed in the soil profile when treated with medium and high liming rate, respectively, compared to low liming rate. We conclude that long-term application of lime in soils receiving yearly P fertilization improved conditions for root growth in soil layers below 30 cm, but at the high liming rate, this did not translate into higher yield. 相似文献