Regional and local scale variations in soil organic carbon stocks in West Greenland     

Philipp Gries  Karsten Schmidt  Thomas Scholten  Peter Kühn 《植物养料与土壤学杂志》2020,183(3):292-305

The soil organic carbon (SOC) pool of the Northern Hemisphere contains about half of the global SOC stored in soils. As the Arctic is exceptionally sensitive to global warming, temperature rise and prolonged summer lead to deeper thawing of permafrost‐affected soils and might contribute to increasing greenhouse gas emissions progressively. To assess the overall feedback of soil organic carbon stocks (SOCS) to global warming in permafrost‐affected regions the spatial variation in SOCS at different environmental scales is of great interest. However, sparse and unequally distributed soil data sets at various scales in such regions result in highly uncertain estimations of SOCS of the Northern Hemisphere and here particularly in Greenland. The objectives of this study are to compare and evaluate three controlling factors for SOCS distribution (vegetation, landscape, aspect) at two different scales (local, regional). The regional scale reflects the different environmental conditions between the two study areas at the coast and the ice margin. On the local scale, characteristics of each controlling factor in form of defined units (vegetation units, landscape units, aspect units) are used to describe the variation in the SOCS over short distances within each study area, where the variation in SOCS is high. On a regional scale, we investigate the variation in SOCS by comparing the same units between the study areas. The results show for both study areas that SOCS are with 8 kg m^?2 in the uppermost 25 cm and 16 kg m^?2 in the first 100 cm of the soil, i.e., 3 to 6 kg m^?2 (37.5%) higher than existing large scale estimations of SOCS in West Greenland. Our approach allows to rank the scale‐dependent importance of the controlling factors within and between the study areas. However, vegetation and aspect better explain variations in SOCS than landscape units. Therefore, we recommend vegetation and aspect for determining the variation in SOCS in West Greenland on both scales.  相似文献   

Cardiorespiratory effects of variable pressure thoracic insufflation in cats undergoing video‐assisted thoracic surgery     

Philipp D. Mayhew  Peter J. Pascoe  Michelle A. Giuffrida  Jeffrey Mitchell  Michele A. Steffey  William T. N. Culp 《Veterinary surgery : VS》2019,48(Z1):O130-O137

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Utility of bronchoscopy combined with surgery in the treatment and outcomes of dogs with intrathoracic disease secondary to plant awn migration     

Erin A. Gibson  Ingrid M. Balsa  Philipp D. Mayhew  Kathryn Phillips  Michelle A. Giuffrida  William T. N. Culp  Michele A. Steffey  Lynelle R. Johnson 《Veterinary surgery : VS》2019,48(7):1309-1317

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Long‐term outcome of video‐assisted thoracoscopic thoracic duct ligation and pericardectomy in dogs with chylothorax: A multi‐institutional study of 39 cases     

Philipp D. Mayhew  Michelle A. Steffey  Boel A. Fransson  Eric G. Johnson  Ameet Singh  William T. N. Culp  Brigitte A. Brisson  Michele L. Oblak  Ingrid M. Balsa  Michelle A. Giuffrida 《Veterinary surgery : VS》2019,48(Z1):O112-O120

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Genotyping-by-sequencing reveals the origin of the Tunisian relatives of cultivated carrot (<Emphasis Type="Italic">Daucus carota</Emphasis>)     

Najla Mezghani  Holly Ruess  Neji Tarchoun  Jihene Ben Amor  Philipp W. Simon  David M. Spooner 《Genetic Resources and Crop Evolution》2018,65(5):1359-1368

Tunisia, other countries in northwestern Africa, and the Iberian Peninsula, represent a center of diversity of Daucus. The genus traditionally has included about 20–25 species worldwide, but a recent molecular study redefined and expanded Daucus to include representatives from nine other genera. By this classification, Daucus now contains about 40 species, with some of them having winged fruits in addition to its traditionally recognized spiny fruits. The taxonomy of Daucus in Tunisia has recently been studied with morphological data, concluding that D. carota subsp. capillifolius is a subspecies that co-occurs and crosses with subsp. carota. The present study extends these findings with additional data from Genotyping-by-Sequencing (GBS) from 33 Tunisian accessions of D. carota (93 individuals with two to three replicates per accession), including the first collections of subsp. gummifer from Tunisia. Placed in the context of additional GBS data, D. carota subsp. gummifer has separate origins from other collections of subsp. carota in Tunisia and/or immediately adjacent areas to the north in Italy or its surrounding islands. Our results add support to the utility of large SNP datasets for species-level phylogenetic studies in Daucus.  相似文献   

Spatial modelling with Euclidean distance fields and machine learning          下载免费PDF全文

T. Behrens  K. Schmidt  R. A. Viscarra Rossel  P. Gries  T. Scholten  R. A. MacMillan 《European Journal of Soil Science》2018,69(5):757-770

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Bioaccumulation of ivermectin from natural and artificial sediments in the benthic organism <Emphasis Type="Italic">Lumbriculus variegatus</Emphasis>     

Tineke Slootweg  Michel Alvinerie  Philipp Egeler  Daniel Gilberg  Jussi V. K. Kukkonen  Jörg Oehlmann  Carsten Prasse  Arto J. Sormunen  Markus Liebig 《Journal of Soils and Sediments》2010,10(8):1611-1622

Purpose  

Although ivermectin is a widely used lipophilic parasiticide, data on its potential bioaccumulation in aquatic invertebrates are scarce. In this study, bioaccumulation patterns of radiolabeled ³H-ivermectin from sediments into tissues of the sediment-dwelling worm Lumbriculus variegatus were investigated and assessed.  相似文献   

Identification of fatty acid esters of pectenotoxin-2 seco acid in blue mussels (Mytilus edulis) from Ireland     

Wilkins AL  Rehmann N  Torgersen T  Rundberget T  Keogh M  Petersen D  Hess P  Rise F  Miles CO 《Journal of agricultural and food chemistry》2006,54(15):5672-5678

Pectenotoxins from marine dinoflagellates of the genus Dinophysis are rapidly hydrolyzed by many shellfish to give pectenotoxin-2 seco acid, which isomerizes to 7-epi-pectenotoxin-2 seco acid. Three series of fatty acid esters of pectenotoxin-2 seco acid (PTX-2 seco acid) and 7-epi-PTX-2 seco acid were detected by LC-MS analysis of extracts from blue mussels (Mytilus edulis) from Ireland. The locations of the fatty acid ester linkages were identified by a combination of LC-MSn in positive- and negative-ion modes, LC-MS analysis of the products from reaction of the esters with sodium periodate, and NMR analysis of purified samples of the two most abundant ester derivatives. The 37-O-acyl esters of PTX-2 seco acid were the most abundant, followed by the corresponding 11-O-acyl esters, accompanied by low levels of the 33-O-acyl esters. The most abundant fatty acid esters in the fractionated sample were, in order, the 16:0, 22:6, 14:0, 16:1, 18:4, and 20:5 fatty acids, although a wide array of other PTX-2 seco acid fatty acid esters were also present at low levels.  相似文献   

Production and isolation of azaspiracid-1 and -2 from Azadinium spinosum culture in pilot scale photobioreactors     

T Jauffrais  J Kilcoyne  V Séchet  C Herrenknecht  P Truquet  F Hervé  JB Bérard  C Nulty  S Taylor  U Tillmann  CO Miles  P Hess 《Marine drugs》2012,10(6):1360-1382

Azaspiracid (AZA) poisoning has been reported following consumption of contaminated shellfish, and is of human health concern. Hence, it is important to have sustainable amounts of the causative toxins available for toxicological studies and for instrument calibration in monitoring programs, without having to rely on natural toxin events. Continuous pilot scale culturing was carried out to evaluate the feasibility of AZA production using Azadinium spinosum cultures. Algae were harvested using tangential flow filtration or continuous centrifugation. AZAs were extracted using solid phase extraction (SPE) procedures, and subsequently purified. When coupling two stirred photobioreactors in series, cell concentrations reached 190,000 and 210,000 cell · mL(-1) at steady state in bioreactors 1 and 2, respectively. The AZA cell quota decreased as the dilution rate increased from 0.15 to 0.3 day(-1), with optimum toxin production at 0.25 day(-1). After optimization, SPE procedures allowed for the recovery of 79 ± 9% of AZAs. The preparative isolation procedure previously developed for shellfish was optimized for algal extracts, such that only four steps were necessary to obtain purified AZA1 and -2. A purification efficiency of more than 70% was achieved, and isolation from 1200 L of culture yielded 9.3 mg of AZA1 and 2.2 mg of AZA2 of >95% purity. This work demonstrated the feasibility of sustainably producing AZA1 and -2 from A. spinosum cultures.  相似文献   

Sow efficiency and early piglet mortality in two local pig breeds on smallholder farms in northern Vietnam—a longitudinal study     

Philipp C. Muth  Le T. T. Huyen  Anne Valle Zárate 《Tropical animal health and production》2017,49(6):1227-1234

In the recent past, pig performance and sow management on smallholder farms in the Southeast Asian Massif have been extensively researched. But the objective of this study was to investigate the lifetime efficiency of breeding sows of the local Vietnamese Ban (n = 89) and Mong Cai (n = 131) breeds in a production system context. The impact of sow longevity was considered in particular. In addition, predictors of early pre-weaning mortality in piglets were investigated. In total, nine villages of Son La province, situated in the uplands of north-western Vietnam, were selected, differing in access to markets, production intensity, and pig management level. Data was collected over a period of 10 years through an on-farm performance testing system. It was shown that sows of both breeds that achieved five or more parities farrowed and weaned significantly more piglets per life year compared to sows with only one or two parities. The conception rate (Spearman’s rho = 0.374) and age at first farrowing (Spearman’s rho = ?0.424) were significantly correlated with the number of weaned piglets per life year of stayable (≥4 parities) Mong Cai sows. The risk of early pre-weaning death of piglets born to Mong Cai sows was affected more by litter size, while for piglets born to Ban sows, the risk was influenced more by the season. Therefore, interventions to improve the sow lifetime efficiency and piglet survivability must match the sow breed and management level.  相似文献