Photosynthetic pigments in soils from northern Victoria Land (continental Antarctica) as proxies for soil algal community structure and function     

Andrea Colacevich  Francesca Borghini 《Soil biology & biochemistry》2009,41(10):2105-321

Although soil algae are among the main primary producers in most terrestrial ecosystems of continental Antarctica, there are very few quantitative studies on their relative proportion in the main algal groups and on how their distribution is affected by biotic and abiotic factors. Such knowledge is essential for understanding the functioning of Antarctic terrestrial ecosystems. We therefore analyzed biological soil crusts from northern Victoria Land to determine their pH, electrical conductivity (EC), water content (W), total and organic C (TC and TOC) and total N (TN) contents, and the presence and abundance of photosynthetic pigments. In particular, the latter were tested as proxies for biomass and coarse-resolution community structure. Soil samples were collected from five sites with known soil algal communities and the distribution of pigments was shown to reflect differences in the relative proportions of Chlorophyta, Cyanophyta and Bacillariophyta in these sites. Multivariate and univariate models strongly indicated that almost all soil variables (EC, W, TOC and TN) were important environmental correlates of pigment distribution. However, a significant amount of variation is independent of these soil variables and may be ascribed to local variability such as changes in microclimate at varying spatial and temporal scales. There are at least five possible sources of local variation: pigment preservation, temporal variations in water availability, temporal and spatial interactions among environmental and biological components, the local-scale patchiness of organism distribution, and biotic interactions.  相似文献   

Serological survey of Encephalitozoon cuniculi in farm rabbits in Italy     

Antonio Santaniello  Laura Rinaldi  Lucia Francesca Menna  Giuseppe Cringoli  Alessandro Fioretti 《Research in veterinary science》2009,87(1):67-71

Rabbit sera (n = 1600) from 40 commercial farms were submitted to a serological screening for Encephalitozoon cuniculi by an enzyme-linked immunosorbent assay (ELISA) and a carbon immunoassay (CIA test). Antibodies anti-Encephalitozoon cuniculi were found in 505/1600 (31.6%) sera analysed, and all the farms (100%) resulted positive. Rabbits older than 4 months showed a significantly higher seropositivity for E. cuniculi (chi-squared test: p < 0.0001) than rabbits under 4 months, E. cuniculi sero-prevalence showed an increasing trend in rabbits within the farm along with the increase in the “number of rabbits on the farm”; however, this trend was not significant (Spearman’s correlation: p = 0.073).The findings of the present study confirm that rabbit is the main reservoir of E. cuniculi; they are of epidemiological relevance and immediate public health importance because of the recognized infectivity in humans by the microsporidium.  相似文献   

HPLC-DAD/MS characterization of flavonoids and hydroxycinnamic derivatives in turnip tops (Brassica rapa L. Subsp. sylvestris L.)     

Romani A  Vignolini P  Isolani L  Ieri F  Heimler D 《Journal of agricultural and food chemistry》2006,54(4):1342-1346

Flavonoids and hydroxycinnamic derivatives of turnip tops (Brassica rapa L. subsp. sylvestris L.) were characterized for the first time in four samples from different origins. Turnip tops exhibit a high polyphenols content (ranging from 107 to 191 mg/100 g, fresh weight) and a good antiradical activity, determined with the DPPH* test. After a liquid-liquid extraction and fractionation procedures, most flavonoids (isorhamnetin, kaempferol, and quercetin glycosides) and hydroxycinnamic derivatives were identified by means of HPLC-DAD/MS techniques. Isorhamnetin glycosides were the main flavonoid derivatives, differing from that found in the vegetables belonging to the Brassica oleracea group.  相似文献   

Distribution and thermal stability of physically and chemically protected organic matter fractions in soils across different ecosystems     

Beatrice?Giannetta  César?Plaza  Costantino?Vischetti  M.?Francesca?Cotrufo  Claudio?ZacconeEmail authorView author&#;s OrcID profile 《Biology and Fertility of Soils》2018,54(5):671-681

Accrual of carbon (C) and nitrogen (N) in soil is a significant and realizable management option to mitigate climate change; thus, a clear understanding of the mechanisms controlling the persistence of C and N in soil organic matter (SOM) across different ecosystems has never been more needed. Here, we investigated SOM distribution between physically and chemically stabilized fractions in soils from a variety of ecosystems (i.e., coniferous and broadleaved forest soils, grassland soils, technosols, and agricultural soils). Using elemental and thermal analyses, we examined changes in the quantity and quality of physically fractionated SOM pools characterized by different mechanisms of protection from decomposition. Independently of the ecosystem type, most of the organic C and total N were found in the mineral-associated SOM pool, known to be protected mainly by chemical mechanisms. Indexes of thermal stability and C/N ratio of this heavy SOM fraction were lower (especially in agricultural soils) compared to light SOM fractions found free or occluded in aggregates, and suggested a marked presence of inherently labile compounds. Our results confirm that the association of labile organic molecules with soil minerals is a major stabilization mechanism of SOM, and demonstrate that this is a generalizable finding occurring across different mineral soils and ecosystems.  相似文献   

IMAGING DIAGNOSIS—ULTRASONOGRAPHIC APPEARANCE OF SKELETAL MUSCLE METASTASES IN A DOG WITH HEMANGIOSARCOMA          下载免费PDF全文

Martina Fabbi  Stefano Di Palma  Sabrina Manfredi  Giacomo Gnudi  Francesca Miduri  Eleonora Daga  Gabriele Costantino Melis  Ezio Bianchi  Simone Voccia  Antonella Volta 《Veterinary radiology & ultrasound》2017,58(6):E64-E67

A 13‐year‐old spayed female German shepherd dog was presented for acute onset of lethargy, anorexia, and disseminated erythematous skin lesions. Thoracic radiographs and abdominal ultrasonographic findings were consistent with metastatic hemangiosarcoma. Multiple, ill‐defined, irregularly shaped hypoechoic nodules were also detected within the thoracic and abdominal wall. Hemangiosarcoma metastases to the skeletal muscle were confirmed based on histopathological examination. Multivisceral involvement was also confirmed by necropsy. Metastatic neoplasia should be considered as a differential diagnosis for dogs with ill‐defined, irregular, hypoechoic, intramuscular nodules.  相似文献   

An integrated pest control strategy against the Asian tiger mosquito in northern Italy: a case study          下载免费PDF全文

Frédéric Baldacchino  Francesca Bussola  Daniele Arnoldi  Matteo Marcantonio  Fabrizio Montarsi  Gioia Capelli  Roberto Rosà  Annapaola Rizzoli 《Pest management science》2017,73(1):87-93

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Corneal anesthetic effect and ocular tolerance of 3.5% lidocaine gel in comparison with 0.5% aqueous proparacaine and 0.5% viscous tetracaine in normal canines          下载免费PDF全文

Francesca Venturi  Tiffany Blocker  Darryl Dustin Dees  Richard Madsen  Julius Brinkis 《Veterinary ophthalmology》2017,20(5):405-410

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Factors Affecting the Growth of Microalgae on Blackwater from Biosolid Dewatering     

Francesca Marazzi  Elena Ficara  Riccardo Fornaroli  Valeria Mezzanotte 《Water, air, and soil pollution》2017,228(2):68

This paper discusses the possibility of including the culturing of microalgae within a conventional wastewater treatment sequence by growing them on the blackwater (BW) from biosolid dewatering to produce biomass to feed the anaerobic digester. Two photobioreactors were used: a 12 L plexiglas column for indoor, lab-scale tests and a 85 L plexiglas column for outdoor culturing. Microalgae (Chlorella sp. and Scenedesmus sp.) could easily grow on the tested blackwater. The average specific growth rate in indoor and outdoor batch tests was satisfactory, ranging between 0.14 and 0.16 day^?1. During a continuous test performed under outdoor conditions from May to November, in which the off-gas from the combined heat and power unit was used as the CO₂ source, an average biomass production of 50 mgTSS L^?1 day^?1 was obtained. However, statistical analyses confirmed that microalgal growth was affected by environmental conditions (temperature and season) and that it was negatively correlated with the occurrence of nitrification. Finally, the biochemical methane potential of the algal biomass was slightly higher than that from waste sludge (208 mLCH₄ gVS^?1 vs. 190 mLCH₄ gVS^?1).  相似文献   

Molecular characterization of <Emphasis Type="Italic">Xiphinema brevicollum</Emphasis> (Nematoda: Longidoridae) from the Czech Republic     

Shesh Kumari  Wilfrida Decraemer  Francesca De Luca 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(2):243-250

Populations of Xiphinema brevicollum occurring in the Czech Republic were described morphologically and molecularly. Published species-specific primer set BL18 and BV3 was used to amplify three populations of X. brevicollum from the Czech Republic. These primers were tested against 9 species of Xiphinema and 11 species of Longidorus. Amplification was also observed for X. inaequale, X. italiae and X. lambertii. Three additional markers, mitochondrial cytochrome c oxidase subunit 1, ribosomal D2/D3 expansion segment of the 28S gene and 18S gene, were amplified and sequenced for X. brevicollum, X. inaequale and X. lambertii belonging to X. americanum-group. Comparison of cox1 sequences of X. brevicollum from the Czech Republic with X. taylori from the Slovak Republic (accession number AM086702) suggested that these populations represent the same species.  相似文献   

Diversity of human copy number variation and multicopy genes     

Sudmant PH  Kitzman JO  Antonacci F  Alkan C  Malig M  Tsalenko A  Sampas N  Bruhn L  Shendure J; Genomes Project  Eichler EE 《Science (New York, N.Y.)》2010,330(6004):641-646

Copy number variants affect both disease and normal phenotypic variation, but those lying within heavily duplicated, highly identical sequence have been difficult to assay. By analyzing short-read mapping depth for 159 human genomes, we demonstrated accurate estimation of absolute copy number for duplications as small as 1.9 kilobase pairs, ranging from 0 to 48 copies. We identified 4.1 million "singly unique nucleotide" positions informative in distinguishing specific copies and used them to genotype the copy and content of specific paralogs within highly duplicated gene families. These data identify human-specific expansions in genes associated with brain development, reveal extensive population genetic diversity, and detect signatures consistent with gene conversion in the human species. Our approach makes ~1000 genes accessible to genetic studies of disease association.  相似文献