Azospirillum inoculation and nitrogen fertilization effect on grain yield and on the diversity of endophytic bacteria in the phyllosphere of rice rainfed crop     

Raúl O. Pedraza  Carlos H. Bellone  Silvia Carrizo de Bellone  Paulo Marcos Fernandes Boa Sorte  Kátia Regina dos Santos Teixeira 《European Journal of Soil Biology》2009,45(1):36-43

We assessed the Azospirillum inoculation and N-fertilization effect on grain yield and on the phyllosphere endophytic diversity of nitrogen-fixing bacteria in a rice rainfed crop. We used cultivation-based techniques and cultivation-independent methods involving PCR-16S rRNA and denaturing gradient gel electrophoresis (DGGE). In general, we observed that grain yield was improved when inoculated with Azospirillum (depending on the genotype) and/or fertilized with urea. A similar behavior was observed in total N-content in grain and the MPN determination, as the highest values occurred when seeds were inoculated with A. brasilense REC3 (S1) than with A brasilense 13-2C (S2). A positive nitrogenase activity and PCR-nifH amplification suggests that the bacteria associated to inner tissues of rice phyllosphere could have contributed to the different N-contents detected. The bacterial diversity, observed in the number and intensity of DGGE profiles, showed a higher number of bands when total DNA was obtained using only CTAB than with CTAB + PVP. The DGGE profiles revealed great stability in the dominating bands, which presumably represent numerically dominant species. Application of A. brasilense strains as inoculants did not influence the dominant members of the endophytic microbial communities in the phyllosphere, but improved N-content and production of rainfed rice crop.  相似文献   

Variability of three regional sources of germplasm of Tejocote (<Emphasis Type="Italic">Crataegus</Emphasis> spp.) from central and southern Mexico     

Carlos A. Núñez-Colín  Raúl Nieto-Ángel  Alejandro F. Barrientos-Priego  Jaime Sahagún-Castellanos  Sergio Segura  Fernando González-Andrés 《Genetic Resources and Crop Evolution》2008,55(8):1159-1165

Tejocote (Crataegus spp.) is a genus of fruit-bearing trees distributed widely throughout Mexico; 13 species are reported for the north and central zones and two or more species may be present in southern Mexico. Accessions of this genus are safeguarded in the Germplasm Bank of Tejocote at the Autonomous University of Chapingo, mainly from three regional sources, i.e. the states of Puebla, Mexico, and Chiapas, including five different species that belong to series Mexicanae and series Crus-galli. They can be morphologically characterized by leaves from different shoot types, flowers and fruits. Multivariate statistical methods were used to elucidate patterns of variation in each of these regional sources. The sources displayed very low intra-source variability. The source from Chiapas showed significant statistical differences in all morphological variables evaluated, as a result, this genetic pool is considered as different from the other two sources. The sources from the states of Puebla and Mexico only differed by 22.79% (with P ≤ 0.05), and thus they could be considered as components of a single genetic pool. The most highly discriminant variables were from the leaf, such as basal angle, petiole length/major axis length ratio, minor axis length/major axis length ratio, and number of veins. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

Dispersant-free dyeing of poly(lactic acid) knitted fabric with temporarily solubilized azo disperse dyes     

Hyun Sung Kim  Young Ki Park  A. Ra Jo  Jung Jin Lee 《Fibers and Polymers》2017,18(7):1263-1268

Poly(lactic acid) (PLA) is known for environmentally friendly material as it is derived from annually renewable crops and biodegradable. Dispersant-free dyeing of PLA fabric with three temporarily solubilized azo disperse dyes which contain β-sulfatoethylsulfonyl group was investigated and their dyeing and fastness properties were compared with those of commercial disperse dyes. The temporarily solubilized azo disperse dyes were successfully applied to PLA fabric without the use of dispersant. The color yield on PLA fabric was dependent on dyebath pH and dyeing temperature as well. The optimum results were obtained at pH 7-8 and 110 °C. The dyes showed markedly higher color yield on PLA fabric when compared to commercial disperse dyes. Wash fastness was very poor to poor but light fastness was good. The COD levels of the dyeing effluent from the temporarily solubilized disperse dyes were considerably lower than those from commercial disperse dyes.  相似文献   

Estradiol-17beta, testosterone, progesterone and cortisol levels in pregnant cows after ACTH administration in various stages of pregnancy     

T Janowski  J Chmiel  S Zduńczyk  A Ra? 《Archiv fuer experimentelle veterinaermedizin》1986,40(6):870-875

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Specificity dependence between serological tests for diagnosing bovine brucellosis in Brucella-free farms showing false positive serological reactions due to Yersinia enterocolitica O:9     

Mainar-Jaime RC  Muñoz PM  de Miguel MJ  Grilló MJ  Marín CM  Moriyón I  Blasco JM 《The Canadian veterinary journal. La revue veterinaire canadienne》2005,46(10):913-916

When brucellosis false positive serological reactions happen in cattle, the serial use of pairs of specificity-correlated serological tests (rose bengal, complement fixation, competitive ELISA) results in specificities lower than expected. In this situation, highly specific tests, such as the indirect ELISA used alone, may be more adequate than serial testing.  相似文献   

Milk yield did not decrease in large herds of high-producing Holstein cows in semi-arid climate of Mexico     

Fernández  Ilda G.  Ulloa-Arvizu  Raúl  Fernández  Jorge 《Tropical animal health and production》2019,51(1):149-154

This study aimed to determine the trends in milk production, fertility, temperature-humidity index (THI), and herd size in dairy herds from the Laguna region in northern Mexico. Records of 16 dairy herds of Holstein cows from January 2002 to December 2016 were used. Milk production was categorized in low and high levels. Milk production and fertility were analyzed using generalized equation estimation procedures by a model of repeated measures that included the effect of year, month, and productive level, an interaction for month × productive level, and herd effect was nested in productive level. For THI, a generalized linear model that included the effects of year and month was used. Dairy herds with high levels of milk production yielded more milk than those with low levels (P?<?0.001). Milk production in 2002 and 2016 was 27.4?±?0.6 and 32.3?±?0.7 L/cow/day, respectively. Fertility fluctuated throughout the study. Dairy herds with high levels of milk production recorded higher fertility than those with low levels (P?<?0.001). From October to April, THI was <?70, whereas it was >?73 from May to September, indicating that cows were in heat stress (20 h/day). The median herd size was 995 and 2569 cows in 2002 and 2016, respectively. In conclusion, in large herds, milk production increased over the years of study, whereas fertility showed a wave cycle; nonetheless, when THI was >?73, both milk production and fertility decreased.

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Alterations of domains in the plasmatic membrane due to damages of the perinuclear theca of pig preserved spermatozoa     

Orozco Benítez MG  Lemus Flores C  Hernández Ballesteros JA  Navarrete Méndez R  Juárez-Mosqueda Mde L 《Pakistan journal of biological sciences: PJBS》2008,11(10):1360-1364

Samples of semen from 12 pigs, three from Yorkshire, Landrace, Duroc and Mexican Hairless each where obtained to study cryopreservation methods. Three stages of boar semen cryopreservation were evaluated: none (fresh stage), cooling at 5 degrees C and freezing at -196 degrees C then thawing to 56 degrees C for 12 sec. Perinuclear theca damage and domain alterations were selected as indices of seminal quality, as measured by electronic and fluorescence microcopy, respectively according to two lineal models considering by separately the effect of semen preservation and breed. Integrity and absence of perinuclear theca significantly (p < 0.001) decreased and increased, respectively according to a decrease in temperature of cryopreservation, from 87.4 to 58.8% and from 0.8 to 26.2%, respectively. This same significant (p < 0.001) effect was found for acrosomal and post-acrosomal membrane distribution of domains, from 92.1 to 76.8% and from 3.1 to 13.1% in this same order. Slight but highly significant (p < 0.001) differences were observed when theca integrity was evaluated as affected by breed, with highest and lowest values for Yorkshire and Pel6n Mexicano pigs, respectively. No breed effect was encountered for presence of acrosomal domains. A strong interdependence was found between perinuclear theca damage and domain distribution. In this connection, a highly significant (p < 0.001) positive, interdependence was observed between the theca damage and acrosomal domain (r = 0.87), while this same relationship was although highly significant (p < 0.001), negative in nature for equatorial and post-acrosonal domains (r = -0.77 and -0.85, respectively). This experiment confirmed that cryopreservation methods may severely affect semen quality of pigs and that genotype may further influence these same indices. More research is needed for improving methods of preservation of pig semen quality, from the point of view of perinuclear theca and domain characteristics of spermatozoa.  相似文献   

Rural O3 Levels in the Middle Ebro Basin During the Plant Growing Season     

Laura González  Raúl Bermejo  María Asunción Parra  David Elustondo  Jordi Garrigó  Jesús Miguel Santamaría 《Water, air, and soil pollution》2010,206(1-4):23-34

Ground-level dynamics of O₃, NO _x and benzene, toluene, ethylbenzene and xylenes were characterised at rural sites in the medium Ebro River Basin (Northern Spain) from April to September (2003–2007) and by means of automated and passive monitoring. The study registered high O₃ levels within the area, which were influenced by traffic emissions, and a monthly evolution of these levels consistent with the occurrence of a broad summer maximum, typical of polluted areas. The mean ozone concentration registered in the studied area by means of passive sampling was 87?±?12 μg m^?3. The 2008/50/EC objective value for the protection of vegetation was widely exceeded during this study (AOT40?=?57,147?±?14,114 μg m^?3 h), suggesting that current ambient levels may pose a risk for crops and vegetation in this important agroindustrial region.  相似文献   

Removal of Indigo Blue in Aqueous Solution Using Fe/Cu Nanoparticles and C/Fe–Cu Nanoalloy Composites     

Jésica Trujillo-Reyes  Víctor Sánchez-Mendieta  Arturo Colín-Cruz  Raúl A. Morales-Luckie 《Water, air, and soil pollution》2010,207(1-4):307-317

Actually, there is a growing interest in finding efficient low-cost materials that allow the removal of chemical substances from water in order to decrease the environmental impact. The use of nanoscale systems is a new area of investigation for the elimination of polluting agents from water among other useful applications in science and technology. In this work, removal of indigo blue in water solutions has been evaluated using Fe/Cu nanoparticles and composites of C/Fe–Cu nanoalloy. The first composite was using carbon obtained by pyrolysis of sewage sludge with Fe/Cu nanoparticles (MCL-NP); the second one was made with commercial activated carbon and Fe–Cu nanoparticles (CAC-NP). Synthesis of materials were carried out by the sodium borohydride reduction of FeSO₄?7H₂O and CuSO₄?5H₂O aqueous mixture. Batch adsorption and isotherm experiments were carried out in order to know the behavior of each adsorbent material employed. The experimental data were adjusted to Langmuir, Freundlich, and BET models.  相似文献   

Central nervous system extracellular matrix changes in a transgenic mouse model of bovine spongiform encephalopathy     

Costa C  Tortosa R  Vidal E  Padilla D  Torres JM  Ferrer I  Pumarola M  Bassols A 《Veterinary journal (London, England : 1997)》2009,182(2):306-314

Bovine spongiform encephalopathy (BSE) is a transmissible spongiform encephalopathy characterised by accumulation of resistant prion protein (PrP^BSE), neuronal loss, spongiosus and glial cell proliferation. In this study, properties of the extracellular matrix (ECM) were investigated in boTg110 transgenic mice over-expressing the bovine cellular prion protein (PrP^c) and infected with BSE. Using immunohistochemistry with Wisteria floribunda agglutinin as a specific marker for perineuronal nets (PNNs) and antibodies against aggrecan and hyaluronic acid binding protein, loss of ECM was correlated with PrP^BSE accumulation and activation of astrocytes and microglia. PrP^BSE accumulation and glial cell activation were detected from the earliest stages of the disease and increased in the terminal stages. Decreases in PNNs, aggrecan and hyaluronic acid were observed only in the terminal stages and correlated with the distribution of PrP^BSE and activated glial cells. This study suggests that the loss of PNNs, aggrecan and hyaluronic acid is a consequence of PrP^BSE accumulation. Degradation of ECM in BSE may be due to secretion of degradative enzymes by activated glial cells.  相似文献