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Anke M. Herrmann Karl Ritz Peta L. Clode Matt R. Kilburn Anthony G. O’Donnell 《Soil biology & biochemistry》2007,39(8):1835-1850
Soils are structurally heterogeneous across a wide range of spatio-temporal scales. Consequently, external environmental conditions do not have a uniform effect throughout the soil, resulting in a large diversity of micro-habitats. It has been suggested that soil function can be studied without explicit consideration of such fine detail, but recent research has indicated that the micro-scale distribution of organisms may be of importance for a mechanistic understanding of many soil functions. Current techniques still lack the adequate sensitivity and resolution for data collection at the micro-scale, and the question ‘How important are various soil processes acting at different scales for ecological function?’ is therefore challenging to answer. The nano-scale secondary ion mass spectrometer (NanoSIMS) represents the latest generation of ion microprobes, which link high-resolution microscopy with isotopic analysis. The main advantage of NanoSIMS over other secondary ion mass spectrometers is its ability to operate at high mass resolution, whilst maintaining both excellent signal transmission and spatial resolution (down to 50 nm). NanoSIMS has been used previously in studies focussing on presolar materials from meteorites, in material science, biology, geology and mineralogy. Recently, the potential of NanoSIMS as a new tool in the study of biophysical interfaces in soils has been demonstrated. This paper describes the principles of NanoSIMS and discusses the potential of this tool to contribute to the field of biogeochemistry and soil ecology. Practical considerations (sample size and preparation, simultaneous collection of isotopes, mass resolution, isobaric interference and quantification of the isotopes of interest) are discussed. Adequate sample preparation, avoiding bias due to artefacts, and identification of regions-of-interest will be critical concerns if NanoSIMS is used as a new tool in biogeochemistry and soil ecology. Finally, we review the areas of research most likely to benefit from the high spatial and high mass resolution attainable with this new approach. 相似文献
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Biochar is a potential micro-environment for soil microorganisms but evidence to support this suggestion is limited. We explored imaging techniques to visualize and quantify fungal colonization of habitable spaces in a biochar made from a woody feedstock. In addition to characterization of the biochar, it was necessary to optimize preparation and observation methodologies for examining fungal colonization of the biochar. Biochar surfaces and pores were investigated using several microscopy techniques. Biochar particles were compared in soilless media and after deposition in soil. Scanning electron microscopy （SEM） observations and characterization of the biochar demonstrated structural heterogeneity within and among biochar particles. Fungal colonization in and on biochar particles was observed using light, fluorescence and electron microscopy. Fluorescent brightener RR 2200 was more effective than Calcofluor White as a hyphal stain. Biochar retrieved from soil and observed using fluorescence microscopy exhibited distinct hyphal networks on external biochar surfaces. The extent of hyphal colonization of biochar incubated in soil was much less than for biochar artificially inoculated with fungi in a soilless medium. The location of fungal hyphae was more clearly visible using SEM than with fluorescence microscopy. Observations of biochar particles colonized by hyphae from soil posed a range of difficulties including obstruction by the presence of soil particles on biochar surfaces and inside pores. Extensive hyphal colonization of the surface of the biochar in the soilless medium contrasted with limited hyphal colonization of pores within the biochar. Both visualization and quantification of hyphal colonization of surfaces and pores of biochar were restricted by two-dimensional imaging associated with uneven biochar surfaces and variable biochar pore structure. There was very little colonization ofbiochar from hyphae in the agricultural soil used in this study. 相似文献
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Isaac Middle Peta Dzidic Amma Buckley Dawn Bennett Marian Tye Roy Jones 《Urban Forestry & Urban Greening》2014,13(4):638-645
When planned coherently, urban green spaces have the potential to provide cities with a range of unique ecosystem services that support ecosystem and human health. This paper draws on existing green space planning literature to argue that the integration of community gardens into standardised and previously under-utilised public park landscapes represents an innovative approach to providing ecosystem services. Particular focus is given to the challenges facing green space planning in Perth, Western Australia. At an individual level, community gardens provide a venue for an alternative and more accessible form of physical activity – gardening – and a restorative park environment that is a more attractive destination for neighbourhood walking. At the community level, gardens can facilitate bridging interactions between different social groups, whilst providing opportunities for local residents to participate actively in green space planning processes. Perhaps most importantly, community gardens can provide unique opportunities for environmental education that lead to enhanced local ecological outcomes. The paper concludes with a brief overview of the main challenges likely to be faced with this integration, and some strategies that may allow them to be overcome. It is hoped this paper will provide a background for future case studies, and a catalyst for increasing integration between formal green space planning and community garden development. 相似文献
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Children absorb tris-BP flame retardant from sleepwear: urine contains the mutagenic metabolite, 2,3-dibromopropanol 总被引：4，自引：0，他引：4
A Blum M D Gold B N Ames F R Jones E A Hett R C Dougherty E C Horning I Dzidic D I Carroll R N Stillwell J P Thenot 《Science (New York, N.Y.)》1978,201(4360):1020-1023
The flame retardant, tris(2,3-dibromopropyl)phosphate (tris-BP), which is a mutagen and causes cancer and sterility in animals is absorbed from fabric by people. 2,3-Dibromopropanol, a metboloite of tris-BP and a mutagen itself, has been found in the urine samples of ten children who were wearing or who had worn tris-BP-treated sleepwear. Eight of these children were wearing well-washed sleepwear and the possibility of absorption of tris-BP from well-washed sleepwear discussed. 2,3-Dibromopropanol was not found in the urines of one child and one adult who had never worn tris-BP-treated garments. 相似文献
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Hymavathi A Devanand P Suresh Babu K Sreelatha T Pathipati UR Madhusudana Rao J 《Journal of agricultural and food chemistry》2011,59(5):1653-1657
The vapor-phase toxicity of Derris scandens Benth.-derived constituents was evaluated against four stored-product pests ( Callosobruchus chinensis L., Sitophilus oryzae L., Rhyzopertha dominica L., and Tribolium castaneum H.) using fumigation bioassays and compared to those of commonly used insecticides. The structures of all constituents of were characterized by spectroscopic analyses [nuclear magnetic resonance (NMR) and mass spectrometry]. The sensitivity of the test insect to compounds varied with exposure time, concentration, and insect species. Over 100% mortality after 24 h was achieved with the compounds osajin (2), scandinone (5), sphaerobioside (8), and genistein (9) against all of the test insects, while laxifolin (3) and lupalbigenin (4) showed 100% mortality after 72 h against T. csataneum and R. dominica . Scandenone (1), scandenin A (6), and scandenin (7) were less effective. Among the insects, C. chinensis , S. oryzae , and R. dominica were more susceptible to the treatments, whereas T. castaneum was less susceptible. The results of fumigation tests indicated that compounds from D. scandens whole plant extract are potential candidates to control stored-product pests. 相似文献
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Katsunori SUNAGAWA Michael J. McKINLEY Brett S. PURCELL Craig THOMSON Peta L. BURNS 《Animal Science Journal》2002,73(1):35-40
The effect of a new peptide, brain urocortin (UCN), in the central regulation of feed and salt intake in parotid fistulated sheep was investigated through a continuous intracerebroventricular (ICV) infusion of the peptide at a small dose for 48 h. Feed and salt intake on day 1 of UCN infusion were similar to those before infusion. However, feed and salt intake on day 2 during UCN infusion decreased significantly. Water intake on days 1 and 2 during UCN infusion was the same as that before infusion. Saliva secretion from the unilateral parotid gland during UCN infusion was unchanged from that before infusion. On the other hand, urine excretion during UCN infusion increased significantly. The present results suggested that UCN acts directly on the brain mechanisms of sheep to decrease feed and salt intake, but does not alter water intake. 相似文献
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Dzidic A Prgomet C Mohr A Meyer K Bauer J Meyer HH Pfaffl MW 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2006,53(4):163-169
Mycophenolic acid (MPA) is a mycotoxin commonly found as Penicillium genus secondary metabolite in feedstuffs and silages. Feeding with MPA contaminated silages may modulate the immune system in the farm animals and can cause appetite lost, ketosis, paralysis and abortion. The aim of the present study was to characterize the long-term MPA effect on both the inosine monophosphate dehydrogenase (IMPDH) isoforms I and II mRNA expression in white blood cells (WBC) and various tissue of healthy sheep. In treated animals 300 mg MPA/day/sheep was applied. In all investigated tissues the IMPDH I and II mRNA was abundant: WBC, spleen, thymus, ileum, jejunum, kidney, liver, pharyngeal and mesenterial lymph node. An efficiency-corrected relative quantification of the IMPDH types I and II isoforms mRNA were performed by normalizing with the constant reference gene expression of beta-actin. High IMPDH I mRNA expression levels were seen in kidney > mesenterial lymph node > jejunum > spleen > pharyngeal lymph node. Medium and low abundance was found in ileum > WBC > liver > thymus. Type II mRNA was highly expressed in liver > thymus > jejunum. In pharyngeal lymph node > spleen > ileum > mesenterial lymph node > kidney > WBC medium to low IMPDH II mRNA concentrations were detected. Under MPA treatment the IMPDH I mRNA expression was not significantly regulated in WBC, only trends of down- and upregulation were observed. Surprisingly in jejunum an upregulation could be observed (P < 0.05). In pharyngeal lymph node a tendency to downregulation was shown. This may be due to frequent ruminant activities and frequent exposition of MPA to the pharyngeal lymph nodes. In contrast to type I mRNA expression, IMPDH II mRNA was significantly downregulated in ileum (3.4-fold, P < 0.01) and tendencies in downregulation could be seen in jejunum (5.1-fold, P = 0.14). In addition, significant downregulation of IMPDH II gene expression over the entire feeding experiment could be shown in WBC of MPA-treated animals compared with untreated animals (P < 0.05). In conclusion, the recent study demonstrates that feeding sheep with MPA-contaminated silage did not induce IMPDH I mRNA expression in various tissues and blood, except in jejunum, but has suppressive effects on IMPDH II mRNA expression in WBC and ileum. 相似文献