Infrared spectroscopy of comet 81P/Wild 2 samples returned by Stardust     

Keller LP  Bajt S  Baratta GA  Borg J  Bradley JP  Brownlee DE  Busemann H  Brucato JR  Burchell M  Colangeli L  d'Hendecourt L  Djouadi Z  Ferrini G  Flynn G  Franchi IA  Fries M  Grady MM  Graham GA  Grossemy F  Kearsley A  Matrajt G  Nakamura-Messenger K  Mennella V  Nittler L  Palumbo ME  Stadermann FJ  Tsou P  Rotundi A  Sandford SA  Snead C  Steele A  Wooden D  Zolensky M 《Science (New York, N.Y.)》2006,314(5806):1728-1731

Infrared spectra of material captured from comet 81P/Wild 2 by the Stardust spacecraft reveal indigenous aliphatic hydrocarbons similar to those in interplanetary dust particles thought to be derived from comets, but with longer chain lengths than those observed in the diffuse interstellar medium. Similarly, the Stardust samples contain abundant amorphous silicates in addition to crystalline silicates such as olivine and pyroxene. The presence of crystalline silicates in Wild 2 is consistent with mixing of solar system and interstellar matter. No hydrous silicates or carbonate minerals were detected, which suggests a lack of aqueous processing of Wild 2 dust.  相似文献   

Detection of porcine circovirus genotypes 2a and 2b in aborted foetuses from infected swine herds in the State of S?o Paulo,Brazil     

Alessandra MMG de Castro  Taís F Cruz  Vanessa R Salgado  Tatiana M Kanashiro  Karen L Ferrari  Jo?o P Araujo  Jr  Paulo E Brand?o  Leonardo J Richtzenhain 《Acta veterinaria Scandinavica》2012,54(1):29

Background

Porcine circovirus type 2 (PCV2) has been associated with several disease complexes, including reproductive failure. The aim of this study was to identify the subtypes of PCV2 that are associated with reproductive failure in pigs from the State of São Paulo, Brazil and to investigate co-infections with other infectious organisms.

Findings

Samples of 168 aborted foetuses or mummified foetuses from five farrow-to-finish swine farms known to be infected with PCV2 and located in the State of São Paulo were tested for PCV2 by polymerase chain reaction (PCR). Positive samples were additionally tested for porcine parvovirus (PPV), Leptospira spp. and Brucella spp. by PCR. PCV2 was detected in 18 of the samples (10.7%). PPV, Brucella spp. and Leptospira spp were found in 2, 10 and 0 cases, respectively. Eleven PCV2 strains were sequenced and determined to be either genotype 2a (n = 1) or 2b (n = 10).

Conclusions

The findings indicate that the frequency of PCV2 infections in aborted porcine foetuses from the State of São Paulo is rather low (10.7%) and that co-infection with other pathogens is common and may be involved in PCV2 associated reproductive failure. No repeatable, characteristic amino acid motifs for regions of the PCV2 capsid protein seemed to be associated with abortion in sows.  相似文献   

Variants of the recently discovered avian gyrovirus 2 are detected in Southern Brazil and The Netherlands     

dos Santos HF  Knak MB  de Castro FL  Slongo J  Ritterbusch GA  Klein TA  Esteves PA  Silva AD  Trevisol IM  Claassen EA  Cornelissen LA  Lovato M  Franco AC  Roehe PM  Rijsewijk FA 《Veterinary microbiology》2012,155(2-4):230-236

A genome of a virus preliminarily named avian gyrovirus 2 (AGV2), a close relative to chicken anemia virus, was recently discovered in a chicken in the state of Rio Grande do Sul, Southern Brazil. To study the occurrence of AGV2 in Rio Grande do Sul and the neighboring state Santa Catarina, a number of adult chickens (n=108 and n=48, respectively) were tested for the presence of AGV2 DNA. An AGV2-specific PCR was developed, optimized and used to analyze DNA extracted from clinical samples. AGV2 DNA was detected in 98/108 (90.7%) of samples collected in the state of Rio Grande do Sul and 29/48 (60.4%) of the samples collected in the state of Santa Catarina. In order to check whether AGV2 DNA would be detected in samples from a geographically distant region, DNA from brain samples of 21 diseased chickens from the Netherlands were tested independently, by the same method. In such specimens, 9/21 (42.9%) brain tissue samples were found to contain AVG2 DNA. Sequence analysis of some of the PCR products demonstrated that the amplified AGV2 sequences could vary up to 15.8% and could preliminarily be divided in three groups. This indicated the occurrence of variants of AGV2, which may reflect differences in geographical origin and/or in biological properties. The data presented here provides evidence that AGV2 seems fairly distributed in chickens in Southern Brazil and that AGV2 also circulates in the Netherlands. Besides, circulating viruses display genetic variants whose significance should be further examined, particularly to determine whether AGV2 would play any role in chicken diseases.  相似文献   

Biological characteristics and pathogenicity of avian Escherichia coli strains.     

Wanderley Dias da Silveira  Alessandra Ferreira  Marcelo Brocchi  Luciana Maria de Hollanda  Antonio Fernando Pestana de Castro  Aureo Tatsumi Yamada  Marcelo Lancellotti 《Veterinary microbiology》2002,85(1):47-53

Fifty avian (chicken) pathogenic Escherichia coli strains (APEC) isolated from individuals suffering from omphalitis, septicaemia and swollen head syndrome, and 30 strains isolated from healthy chickens were studied regarding their biological characteristics such as serogroups, haemolysin, colicin, cytotoxin, toxin and siderophore production, adhesion capacity to in vitro cultivated cells, and absorption of Congo red dye. Serotyping demonstrated that most of the omphalitis and normal strains were untypable, whereas most of the septicaemic strains were either untypable or rough. There was no prevalent serogroup among the pathogenic strains studied. The capacity for adhesion and invasion of in vitro cultured cells (HeLa, HEp-2, KPCC), as well as the agglutination of different types of red blood cells and the LD50 of each strain were also evaluated. No correlation was observed between the biological characteristics and pathogenicity, except that colicin was characteristically produced by swollen head syndrome E. coli strains. No correlation was found between adhesion or haemagglutination patterns and pathogenicity. Only six of the 50 strains revealed invasive capacity and the strain that best invaded the cell lines was the one with the lowest LD50.  相似文献   

Effects of milk feeding, frequency and concentration on weaning and buffalo (Bubalus bubalis) calf growth, health and behaviour     

Domenico Vecchio  Rossella Di Palo  Esterina De Carlo  Luigi Esposito  Giorgio Antonio Presicce  Alessandra Martucciello  Emilio Chiosi  Pasquale Rossi  Gianluca Neglia  Giuseppe Campanile 《Tropical animal health and production》2013,45(8):1697-1702

Growth, weight at birth and daily weight gain (DWG) on 12 water buffalo calves, starting from 6 days of age until completion of weaning, was investigated in this study. Different feeding regimens were given to two groups of animals with regard to daily milk replacer: (1) group 1 (G1) received a double concentration in single administration; whereas (2) group 2 (G2) received the same amount of milk replacer split twice daily. Blood samples were collected from each calf on days 6, 30, 60 and 90 to evaluate acute phase proteins (haptoglobin), bactericide activity, lysozime, total protein content and biochemical parameters. No differences were observed between the two groups in terms of dry matter intake, feed efficiency and live body weight at the end of the study. Interestingly, a significantly (P?<?0.05) reduced DWG was observed earlier in G1 (day 45) than in G2 (day 60). Gastrointestinal disorders were not recorded throughout the experimental period, and no significant differences were recorded between the two groups for all considered parameters. This study confirms the possibility of utilising one daily administration of milk replacer in water buffalo calf during weaning. This new approach facilitates calves management, without interfering with calves growing performances.  相似文献   

Adverse Effect of Antifouling Compounds on the Reproductive Mechanisms of the Ascidian Ciona intestinalis     

Alessandra Gallo  Elisabetta Tosti 《Marine drugs》2013,11(9):3554-3568

Fertilization and embryo development that occur in sea water are sensitive to xenobiotics from anthropogenic sources. In this work, we evaluated the influence of two antifouling biocides, tributyltin (TBT) and diuron, on the reproductive mechanisms of the marine invertebrate Ciona intestinalis. By using electrophysiological techniques, we examined the impact of these compounds on the electrical properties of the mature oocytes and of events occurring at fertilization. With different toxicity assays, we studied the effect of the two biocides on the gametes by evaluating fertilization rate and embryo development. Results show that sodium (Na⁺) currents were significantly reduced by either of the two biocides, whereas conductance was significantly increased. The fertilization current frequency and amplitude, fertilization rate and larval development were affected only by TBT. This study suggests that: (i) the two biocides affect either the electrical properties of the oocyte plasma membrane and the reproductive success representing a risk factor for the survival of the species exposed to environmental pollution; (ii) the ascidian Ciona intestinalis may represent a good model organism to test toxicity of marine pollutants. Possible mechanisms of action of the two biocides are discussed.  相似文献   

Extracts of Peels and Seeds of Five Varieties of Brazilian Jabuticaba Present High Capacity to Deactivate Reactive Species of Oxygen and Nitrogen     

Paludo  Michelly Cristiane  de Oliveira  Luciana Fontes  Hermosín-Gutiérrez  Isidro  Ballus  Cristiano Augusto  Ribeiro  Alessandra Braga  de Oliveira  Silvia Borges Pimentel  Godoy  Helena Teixeira 《Plant foods for human nutrition (Dordrecht, Netherlands)》2019,74(1):135-140

Plant Foods for Human Nutrition - Jabuticaba has a high concentration of phenolic compounds, which have a significant antioxidant capacity. Methodologies have been developed to evaluate the ability...  相似文献   

Bioactive constituent production in St. John's Wort in vitro hairy roots. Regenerated plant lines     

Bertoli A  Giovannini A  Ruffoni B  Guardo AD  Spinelli G  Mazzetti M  Pistelli L 《Journal of agricultural and food chemistry》2008,56(13):5078-5082

A wild strain of Agrobacterium rhizogenes was used to regenerate twelve in vitro plant lines from different hairy roots of H. perforatum (St. John's Wort). The production of the main bioactive constituents was observed even though their yields varied in the different plant lines. Two lines were selected for the hyperoside production (4.9-4.6 mg/gdw) while nine were characterized by significant yields of chlorogenic acid (ranged from 0.47 to 1.09 mg/gdw). Furthermore, one out of twelve lines showed a 10-fold higher hypericin content (0.25 mg/gdw) than that reported for the in vitro shoots in the literature. Morphological and phytochemical features were determined in order to select H. perforatum genotypes enriched in valuable bioactive compounds.  相似文献   

Effects of fly attack (Bactrocera oleae) on the phenolic profile and selected chemical parameters of olive oil     

Gómez-Caravaca AM  Cerretani L  Bendini A  Segura-Carretero A  Fernández-Gutiérrez A  Del Carlo M  Compagnone D  Cichelli A 《Journal of agricultural and food chemistry》2008,56(12):4577-4583

The phenolic fraction of virgin olive oil influences both its quality and oxidative stability. One of the principal threats of the quality of olive fruit is the olive fly ( Bactrocera oleae) as it alters the chemical composition. The attack of this olive pest has been studied in order to evaluate its influence on the quality of virgin olive oil (free acidity, peroxide value, fatty acid composition, water content, oxidative stability, phenols, and antioxidant power of phenolic fraction). The study was performed using several virgin olive oils obtained from olives with different degrees of fly infestation. They were acquired in different Italian industrial mills from the Abruzzo region. Qualitative and quantitative analyses of phenolic profiles were performed by capillary electrophoresis-diode array detection, and electrochemical evaluation of the antioxidant power of the phenolic fraction was also carried out. These analyses demonstrated that the degree of fly attack was positively correlated with free acidity ( r = 0.77, p < 0.05) and oxidized products ( r = 0.58, p < 0.05), and negatively related to the oxidative stability index ( r = -0.54, p < 0.05) and phenolic content ( r = -0.50, p < 0.05), mainly with secoiridoid compounds. However, it has been confirmed that the phenolic fraction of olive oil depends on several parameters and that a clear correlation does not exist between the percentages of fly attack and phenolic content.  相似文献   

Occurrence of fatal canine Angiostrongylus vasorum infection in Italy     

Traversa D  Torbidone A  Malatesta D  Guglielmini C 《Veterinary parasitology》2008,154(1-2):162-166

A total of 469 fecal samples were collected from American minks (Mustela vison) on a farm in Hebei Province in China and examined for Cryptosporidium by Sheather's sugar flotation technique and 8 Cryptosporidim isolates were obtained. The partial 18S rRNA, 70 kDa heat shock protein (HSP70), Cryptosporidium oocyst wall protein (COWP) and actin genes of six isolates were sequenced. Sequence data were analyzed together with known Cryptosporidium spp. and genotypes. Results of this multi-locus genetic characterization indicated that the six Cryptosporidium isolates in this study shared the same sequences of the genes studied and were different from known Cryptosporidium species and genotypes. The closest relative was Cryptosporidium ferret genotype with 7, 22, 2 and 2 nucleotide differences in the 18S rRNA, HSP70, COWP and actin genes, respectively. The homology to ferret genotype at the 18S rRNA locus was 99.1%, which is comparable to that between C. parvum and C. hominis (99.2%), or between C. muris and C. andersoni (99.4%). Therefore, the Cryptosporidium in minks in this study is considered a new genotype, the Cryptosporidium mink genotype.  相似文献