Endocrine (plasma cortisol and glucose) and behavioral (locomotor and self-feeding activity) circadian rhythms in Senegalese sole (Solea senegalensis Kaup 1858) exposed to light/dark cycles or constant light     

Catarina C. V. Oliveira  Rocio Aparício  Borja Blanco-Vives  Olvido Chereguini  Ignacio Martín  F. Javier Sánchez-Vazquez 《Fish physiology and biochemistry》2013,39(3):479-487

The existence of daily rhythms under light/dark (LD) cycles in plasma cortisol, blood glucose and locomotor and self-feeding activities, as well as their persistence (circadian nature) under constant light (LL), was investigated in Senegalese sole (Solea senegalensis). For the cortisol and glucose rhythms study, 48 soles were equally distributed in 8 tanks and exposed to a 12:12 LD cycle and natural water temperature (experiment 1). After an acclimation period, blood was sampled every 3 h until a 24-h cycle was completed. Blood glucose levels were measured immediately after sampling, while plasma cortisol was measured later by ELISA. In experiment 2, the fish were exposed to LL for 11 days, and after this period, the same sampling procedure was repeated. For the study of locomotor and self-feeding rhythms (experiment 3), two groups of sole were used: one exposed to LD and the other to LL. Each group was distributed within 3 tanks equipped with infrared photocells for the record of locomotor activity, and self-feeders for feeding behavior characterization. The results revealed a marked oscillation in cortisol concentrations during the daily cycle under LD, with a peak (35.65 ± 3.14 ng/ml) in the afternoon (15:00 h) and very low levels during the night (5.30 ± 1.09 ng/ml). This cortisol rhythm persisted under LL conditions, with lower values (mean cortisol concentration = 7.12 ± 1.11 ng/ml) and with the peak shifted by 3 h. Both rhythms were confirmed by COSINOR analysis (p < 0.05). The synchronizing role of temperature and feeding schedule, in addition to light, is also discussed. Diel rhythms of glucose were not evident in LD or LL. As to locomotor and self-feeding activity, a very marked rhythm was observed under LD, with higher activity observed during the night, with acrophases located at 2:14 and 3:37 h, respectively. The statistical significance of daily rhythms was confirmed by COSINOR analysis. Under LL, both feeding and locomotor rhythms persisted, with an endogenous period (τ) around 22.5 h. In short, our findings described for the first time the existence of circadian cortisol and behavioral circadian rhythms in flat fish. Such results revealed the importance of taking into account the time of day when assessing stress responses and evaluating physiological indicators of stress in fish.  相似文献   

Tobacco mottle leaf curl virus, a new begomovirus infecting tobacco in Cuba     

M. Domínguez  P. L. Ramos  Y. Sánchez  J. Crespo  V. Andino  M. Pujol  C. Borroto 《Plant pathology》2009,58(4):786-786

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VCG and AFLP analyses identify the same groups in the causal agents of mango malformation in Brazil     

Cristiano S. Lima  Jean H. A. Monteiro  Natália C. Crespo  Sarah S. Costa  John F. Leslie  Ludwig H. Pfenning 《European journal of plant pathology / European Foundation for Plant Pathology》2009,123(1):17-26

The causal agents of mango malformation disease in Brazil are a new Fusarium lineage in the Gibberella fujikuroi species complex and Fusarium sterilihyphosum; however information on the genetic and geographical diversity of these pathogens in Brazil is missing. Vegetative compatibility group (VCG) and amplified fragment length polymorphism (AFLP) analyses were used to measure the genetic diversity within these populations. Both techniques identified the same genetic groups. Six VCG and AFLP groups were identified amongst isolates of the new lineage from Brazil. FB-VCG 1/AFLP I was the most widespread group, found in seven of the 13 sites sampled. The second most frequent group was recovered from three sites. The remaining four groups were recovered from single-sites. We think that this lineage represents a genetically and geographically diverse indigenous population that reproduces clonally. In F. sterilihyphosum, group FS-VCG 1/AFLP VII was found at three sites in the southeast region of Brazil. FS-VCG 2/AFLP VIII contained isolates from South Africa but not from Brazil. Fusarium mangiferae isolates from India and South Africa formed one group, while isolates from Egypt and the USA formed a second group. F. sterilihyphosum at present is represented by a small population that might have been introduced only once into a restricted area. The clonal nature of the observed populations suggests that these fungi either occur naturally on indigenous hosts and have jumped to the introduced mango host (introduced in Brazil) or that they originated with mango and went through a severe population bottleneck when they were introduced to Brazil from India or Southeast Asia.  相似文献   

A psbA mutation (Val219 to Ile) causes resistance to propanil and increased susceptibility to bentazon in Cyperus difformis          下载免费PDF全文

Rafael M Pedroso  Kassim Al‐Khatib  Rocio Alarcón‐Reverte  Albert J Fischer 《Pest management science》2016,72(9):1673-1680

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Pathology of Edwardsiella tarda infection in turbot, Scophthalmus maximus (L.)     

Padrós F  Zarza C  Dopazo L  Cuadrado M  Crespo S 《Journal of fish diseases》2006,29(2):87-94

Macroscopic and histopathological changes in cultured turbot, Scophthalmus maximus (L.), in Spain caused by infection with Edwardsiella tarda are described. Eye tumefaction, inflammation, haemorrhages, ascites and the presence of a purulent fluid were the main macroscopic lesions observed. Histopathological lesions were found in the kidney, spleen and liver. In the kidney and spleen these were characterized by a severe apostematous inflammatory reaction, with a large number of abscesses. The liver was affected to a lesser degree and only some phagocytes loaded with bacteria were observed. Ultrastructural observations indicated that macrophages were the main cell type implicated in the inflammatory response. Most of the bacteria observed within the phagocyte cytoplasm showed no degenerative changes and some were dividing. Degenerative changes observed in macrophages indicate their failure in preventing the infection.  相似文献   

The effect of two pre-cryopreservation single layer colloidal centrifugation protocols in combination with different freezing extenders on the fragmentation dynamics of thawed equine sperm DNA     

Luna Gutiérrez-Cepeda  álvaro Fernández  Francisco Crespo  Miguel ángel Ramírez  Jaime Gosálvez  Consuelo Serres 《Acta veterinaria Scandinavica》2012,54(1):72

Background

Variability among stallions in terms of semen cryopreservation quality renders it difficult to arrive at a standardized cryopreservation method. Different extenders and processing techniques (such us colloidal centrifugation) are used in order to optimize post-thaw sperm quality. Sperm chromatin integrity analysis is an effective tool for assessing such quality. The aim of the present study was to compare the effect of two single layer colloidal centrifugation protocols (prior to cryopreservation) in combination with three commercial freezing extenders on the post-thaw chromatin integrity of equine sperm samples at different post-thaw incubation (37°C) times (i.e., their DNA fragmentation dynamics).

Results

Post-thaw DNA fragmentation levels in semen samples subjected to either of the colloidal centrifugation protocols were significantly lower (p<0.05) immediately after thawing and after 4 h of incubation at 37°C compared to samples that underwent standard (control) centrifugation. The use of InraFreeze® extender was associated with significantly less DNA fragmentation than the use of Botu-Crio® extender at 6 h of incubation, and than the use of either Botu-Crio® or Gent® extender at 24 h of incubation (p<0.05).

Conclusions

These results suggest that single layer colloidal centrifugation performed with extended or raw semen prior to cryopreservation reduces DNA fragmentation during the first four hours after thawing. Further studies are needed to determine the influence of freezing extenders on equine sperm DNA fragmentation dynamics.  相似文献   

Onion biomass monitoring using UAV-based RGB imaging     

Rocio?BallesterosEmail author  Jose?Fernando?Ortega  David?Hernandez  Miguel?Angel?Moreno 《Precision Agriculture》2018,19(5):840-857

Biomass monitoring is one of the main pillars of precision farm management as it involves deeper knowledge about pest and weed status, soil quality, water stress, and yield prediction, among others. This research focuses on estimating crop biomass from high-resolution red, green, blue imaging obtained with an unmanned aerial vehicle. Onion, as one of the most cultivated vegetables, was studied for two seasons under non-controlled conditions in two commercial plots. Green canopy cover, crop height, and canopy volume (V_canopy) were the predictor variables extracted from the geomatic products. Strong relationships were found between V_canopy and dry leaf biomass and dry bulb biomass. Adjusted coefficient of determination (\({\text{R}}_{\text{adj}}^2\)) values were 0.76 and 0.95, respectively. Nevertheless, crop management practices and leaf depletion at vegetative stages significantly affect the accuracy of the canopy model. These results suggested that obtaining biomass using aerial images are a good alternative to other sensors and platforms as they have high spatial and temporal resolution to perform high-quality biomass monitoring.  相似文献   

Signaling pathways involved in liver injury and regeneration in rabbit hemorrhagic disease, an animal model of virally-induced fulminant hepatic failure     

Rodrigo García-Lastra  Beatriz San-Miguel  Irene Crespo  Francisco Jorquera  Marcelino Alvarez  Javier González-Gallego  María J. Tu?ón 《Veterinary research》2010,41(1)

Management of fulminant hepatic failure (FHF) continues to be one challenging problem, and experimental animal models resembling its clinical conditions are still needed. Rabbit hemorrhagic disease (RHD) fullfils many requirements of an animal model of FHF. This work investigated changes in MAPK, NF-κB, AP-1 and STAT pathways during RHD-induced liver injury. Rabbits were infected with 2 × 10⁴ hemagglutination units of an RHD virus isolate. Apoptosis was documented by the presence of caspase-3 activity and substantial PARP proteolysis at 36 and 48 h postinfection (pi). Infection induced a marked and maintained expression of TNF-α from 12 h pi, while there was only a transitory increase in IL-6 expression. Expression of phosphorylated (p)-JNK, p-p38 and p-ERK1/2 was significantly elevated at 12 h pi. At 48 h pi p-JNK expression was maintained at a maximum level, while that of p-p38 returned to normality and there was no p-ERK1/2 expression. Activation of NF-κB and AP-1 and increased expression of VCAM-1 and COX-2 were observed. No significant changes were detected in activation of STAT1 and STAT3, while SOCS3 expression increased significantly. The current findings suggest that activation of JNK is an essential component in liver injury mediated by the RHD virus and that lack of activation of STAT3, probably mediated by SOCS3 over-expression, would contribute to the inhibition of the regenerative response. Data show the presence of molecular mechanisms contributing to liver damage and the lack of regeneration and they support the usefulness of this model to investigate novel therapeutical modalities in FHF.  相似文献   

New Insights on the Terpenome of the Red Seaweed Laurencia dendroidea (Florideophyceae,Rhodophyta)     

Louisi Souza de Oliveira  Diogo Antonio Tschoeke  Aline Santos de Oliveira  Lilian Jorge Hill  Wladimir Costa Paradas  Leonardo Tavares Salgado  Cristiane Carneiro Thompson  Renato Crespo Pereira  Fabiano L. Thompson 《Marine drugs》2015,13(2):879-902

The red seaweeds belonging to the genus Laurencia are well known as halogenated secondary metabolites producers, mainly terpenoids and acetogennins. Several of these chemicals exhibit important ecological roles and biotechnological applications. However, knowledge regarding the genes involved in the biosynthesis of these compounds is still very limited. We detected 20 different genes involved in the biosynthesis of terpenoid precursors, and 21 different genes coding for terpene synthases that are responsible for the chemical modifications of the terpenoid precursors, resulting in a high diversity of carbon chemical skeletons. In addition, we demonstrate through molecular and cytochemical approaches the occurrence of the mevalonate pathway involved in the biosynthesis of terpenes in L. dendroidea. This is the first report on terpene synthase genes in seaweeds, enabling further studies on possible heterologous biosynthesis of terpenes from L. dendroidea exhibiting ecological or biotechnological interest.  相似文献   

Operational interactions between South American sea lions and gillnet fishing in southern Brazil          下载免费PDF全文

Paulo Henrique Ott  Ignacio Benites Moreno  Daniel Danilewicz  Maurício Tavares  Enrique Alberto Crespo  Salvatore Siciliano  Larissa Rosa De Oliveira 《水产资源保护:海洋与淡水生态系统》2016,26(1):108-120