Rights‐based fisheries governance: from fishing rights to human rights     

Edward H Allison  Blake D Ratner  Björn Åsgård  Rolf Willmann  Robert Pomeroy  John Kurien 《Fish and Fisheries》2012,13(1):14-29

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Biological P cycling is influenced by the form of P fertilizer in an Oxisol     

Andrew?J.?MargenotEmail author  Rolf?Sommer  John?Mukalama  Sanjai?J.?Parikh 《Biology and Fertility of Soils》2017,53(8):899-909

Phosphate rock (PR) is an alternative fertilizer to increase the P content of P-deficient weathered soils. We evaluated the effects of fertilizer form on indicators of biological cycling of P using an on-farm trial on a Rhodic Kandiudox in western Kenya. Treatment plots were sampled after 13 cropping seasons of P applications as Minjingu phosphate rock (PR) or as triple super phosphate (?TSP) (50 kg P ha^?1 season^?1), as well as a P-unfertilized control (0 kg P ha^?1 season^?1). Soils (0–15 and 15–30 cm) were analyzed for microbial biomass P (P_mic), activities of acid phosphomonoesterase, alkaline phosphomonoesterase, and phosphodiesterase, and sequentially extractable P fractions. P additions as Minjingu PR yielded 299% greater P_mic than TSP at 0–15-cm depth despite similar labile P concentrations in the two P fertilization treatments and stimulated activities of acid phosphomonoesterase (+39%). When added in the soluble form of TSP, a greater percentage of total soil P was present in mineral-bound forms (+33% Fe- and Al-associated P). Higher soil pH under Minjingu PR (pH 5.35) versus TSP (pH 5.02) and the P-unfertilized treatment (pH 4.69) at 0–15-cm depth reflected a liming effect of Minjingu PR. The form of P fertilizer can influence biological P cycling in weathered soils, potentially improving P availability under Minjingu PR relative to TSP via enhanced microbial biomass P and enzymatic drivers of P cycling.  相似文献   

<Emphasis Type="Italic">Colletotrichum acutatum</Emphasis> occurs asymptomatically on sweet cherry leaves     

Jorunn Børve  Rolf Tore Djønne  Arne Stensvand 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(3):325-332

Leaves of sweet cherry, exposed to either paraquat or freezing to quickly senesce the leaf tissue, were incubated in about 100% RH at 25°C for 6 d. Sporulating colonies of Colletotrichum acutatum, the cause of anthracnose, developed on up to 100% of the paraquat-treated and frozen leaves, and on none of the untreated controls. Number of leaves and leaf area containing C. acutatum on naturally infected leaves increased over time from May to September. Mean incidence of C. acutatum on leaf blades on fruit spurs and vegetative shoots from eight orchard/year samplings were 41 and 33%, respectively. Secondary conidiation (formation of short hyphae and new conidia) from conidia applied to detached leaves took place 6 h after inoculation, but only up to 3% of the conidia formed new conidia. It may be concluded that asymptomatic sweet cherry leaves frequently host C. acutatum and may be a potential inoculum source for cherry fruit.  相似文献   

Presence of arsenic resistance in Salmonella enterica serovar Kentucky and other serovars isolated from poultry     

Joerger RD  Hanning IB  Ricke SC 《Avian diseases》2010,54(4):1178-1182

A collection of 125 Salmonella enterica poultry isolates (71 serovar Kentucky isolates, and the remainder belonging to serovars Alachua, Enteritidis, Hadar, Heidelberg, Montevideo, Mbandaka, Senftenberg, Typhimurium, and Worthington) were tested for the ability to grow on tryptic soy agar containing sodium arsenite [As(III)] or arsenate [As(V)]. All serovar Kentucky isolates and 18 of the non-Kentucky isolates were able to grow in the presence of 0.1 mM As(III), and 69 grew in the presence of 1 mM As(V). Thirty of the non-Kentucky isolates did not grow at these As(III) and As(V) concentrations, but seven grew at 1 mM As(III) and 10 mM As(V). PCR-based analysis demonstrated the presence of arsB and arsD sequences in all Kentucky isolates, whereas one or both of these sequences were present in only 30 of the other isolates. It remains to be determined if these arsenic-resistance determinants benefit Salmonella exposed to man-made arsenic-containing compounds in poultry environments.  相似文献   

Detection of all Chlamydophila and Chlamydia spp. of veterinary interest using species-specific real-time PCR assays     

Alexandra Pantchev  Reinhard Sting  Rolf Bauerfeind  Judith Tyczka  Konrad Sachse   《Comparative immunology, microbiology and infectious diseases》2010,33(6):473-484

The aim of the present study was to analyse the occurrence of chlamydiae in several mammalian host species. Clinical samples that previously tested positive in a Chlamydiaceae-specific real-time PCR were retested using six species-specific real-time PCR assays to identify the chlamydial species involved. Chlamydophila (Cp.) abortus was the agent most frequently found in cattle, sheep, horses, goats, and pigs. Detection in cattle of Cp. psittaci (11% of samples) and Chlamydia (C.) suis (9%), as well as Cp. psittaci in a goat sample was somewhat unexpected. DNA of two different chlamydiae was identified in 56 (12.7%) of 440 samples tested. Cp. felis was the predominant species found in cats, while in guinea pigs and rabbits only Cp. caviae was detected. Interestingly, the latter two pathogens were also identified in samples from dogs. The data show that mixed chlamydial infections are not rare and suggest an extended host range of individual species.  相似文献   

The inhibiting effect of nitrate fertilisation on methane uptake of a temperate forest soil is influenced by labile carbon   总被引：1，自引：0，他引：1  

Ann-Catrin Fender  Birgit Pfeiffer  Dirk Gansert  Christoph Leuschner  Rolf Daniel  Hermann F. Jungkunst 《Biology and Fertility of Soils》2012,48(6):621-631

Upland soils are the most important terrestrial sink for the greenhouse gas CH₄. The oxidation of CH₄ is highly influenced by reactive N which is increasingly added to many ecosystems by atmospheric deposition and thereby also alters the labile C pool in the soils. The interacting effects of soil N availability and the labile C pool on CH₄ oxidation are not well understood. We conducted a laboratory experiment with soil columns consisting of homogenised topsoil material from a temperate broad-leaved forest to study the net CH₄ flux under the combined or isolated addition of NO ₃ ^? and glucose as a labile C source. Addition of NO ₃ ^? and glucose reduced the net CH₄ uptake of the soil by 86% and 83%, respectively. The combined addition of both agents led to a nearly complete inhibition of CH₄ uptake (reduction by 99.4%). Our study demonstrates a close link between the availability of C and N and the rate of CH₄ oxidation in temperate forest soils. Continued deposition of NO ₃ ^? has the potential to reduce the sink strength of temperate forest soils for CH₄.  相似文献   

Re‐visiting potassium‐ and phosphate‐fertilizer responses in field experiments and soil‐test interpretations by means of data mining     

Rolf O. Kuchenbuch  Uwe Buczko 《植物养料与土壤学杂志》2011,174(2):171-185

Currently, potassium (K)‐ and phosphate (P)‐fertilizer recommendation in Germany is based on standardized soil‐testing procedures, the results of which are interpreted in terms of nutrient availability. Although site‐specific soil and plant properties (e.g., clay and carbon content, pH, crop species) influence the relation between soil nutrient content and fertilizer effectiveness, most of these factors are not accounted for quantitatively when assessing fertilizer demand. Recent re‐evaluations of field observations suggest that even for soil nutrient contents well within the range considered to indicate P or K deficiency, fertilizer applications often resulted in no yield increase. In this study, results from P‐ and K‐fertilization trials (in total about 9000 experimental harvests) conducted during the past decades in Germany and Austria were re‐analyzed using a nonparametric data‐mining procedure which consists of a successive segmentation of the data pool in order to elaborate a modified recommendation scheme. In addition to soil nutrient content, fertilizer‐application rates, nutrient‐use efficiency, and site properties such as pH, clay content, and soil organic matter, have a distinct influence on yield increase compared to an unfertilized control. For K, nutrient‐use efficiency had the largest influence, followed by soil‐test K content, whereas for P, the influence of soil‐test P content was largest, followed by pH and clay content. The results may be used in a novel approach to predict the probability of yield increase for a specified combination of crop species, fertilizer‐application rate, and site‐specific data.  相似文献   

Systemic and local effects of lidocaine or mepivacaine when used for intravenous regional anaesthesia of the distal limb in standing sedated horses     

Jose L. Mendez-Angulo  Maria M. Granados  Rolf Modesto  Juan M. Serrano-Rodriguez  Francisco J. Funes  Setefilla Quiros  Rafael J. Gomez-Villamandos  Sara Zaldívar  Troy N. Trumble 《Equine veterinary journal》2020,52(5):743-751

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Theorie eines Doppel-Membran-Apparates zur Bestimmung der kapillaren Leitfähigkeit von Bodenproben     

Rolf Koitzsch 《Archives of Agronomy and Soil Science》2013,59(1-3):47-60

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Soil influence on landmine detection—insights from a field study in Mozambique     

Holger Preetz  Christian Rolf  Jan Igel 《Journal of Soils and Sediments》2013,13(3):585-605

Purpose

Electromagnetic induction based metal detectors are commonly used in landmine clearance operations. Their performance can be seriously deteriorated by magnetic properties of the soil in which the landmines are buried.

Materials and methods

Soil magnetic parameters were studied at three locations in Southern Mozambique where soils had caused severe problems during former landmine clearance campaigns. Field work comprised a geological and pedological survey of soils and the parent rock materials. Soil and rock samples were analyzed to determine pedological standard parameters and magnetic susceptibility. Geochemical analysis, scanning electron microscopy, and thermomagnetic analysis helped to clarify the mineral composition and to specify the origin and properties of the magnetic minerals. The spatial distribution of the topsoil magnetic susceptibility was investigated in the field and characterized using geostatistical analyses.

Results and discussion

Despite different degrees of weathering of the investigated soils, their magnetic mineral composition is dominated by lithogenic (Ti-) magnetites. Moreover, there are clues for the pedogenic neoformation of ultrafine-grained ferrimagnetic minerals in two of the three topsoils. The deterioration of metal detector performance at the sites results from the high frequency dependence of magnetic susceptibility at two locations and from the distinct spatial variability of topsoil magnetic susceptibility at all locations.

Conclusions

To assess soil effects on the performance of modern metal detectors the investigations of frequency-dependent susceptibility and of spatial susceptibility distribution are the most meaningful tools. Summarizing, the topsoil magnetic properties of the investigated sites are predominantly influenced by their parent material and to a minor degree by pedogenic neoformation.  相似文献