Prevalence of Rickettsia species antibodies and Rickettsia species DNA in the blood of cats with and without fever     

Bayliss DB  Morris AK  Horta MC  Labruna MB  Radecki SV  Hawley JR  Brewer MM  Lappin MR 《Journal of Feline Medicine and Surgery》2009,11(4):266-270

Rickettsia species antibodies have been detected in some cats but it is unknown whether infected cats develop clinical signs. The prevalence of Rickettsia species deoxyribonucleic acid (DNA) in blood from clinically ill cats has not been determined. The objective of this study was to determine if cats with fever (body temperature >or=102.5 degrees F [39.2 degrees C]) were more likely to have evidence of rickettsial infection than healthy, age-matched, control cats with a body temperature<102.5 degrees F. Rickettsia species polymerase chain reaction (PCR) assays were performed to detect rickettsial DNA extracted from blood (71 paired samples), indirect immunofluorescence assays (IFA) were performed to detect serum antibodies against Rickettsia felis (90 paired samples) and Rickettsia rickettsii (91 paired samples), and the results between pairs were compared. All samples were negative for Rickettsia species DNA. More cats with fever were seropositive for R felis or R rickettsii than control cats, but results were not statistically significant. Results of this pilot study failed to show an association between Rickettsia species DNA or Rickettsia species antibodies and fever.  相似文献   

Powdery mildew development is positively influenced by grapevine vegetative growth induced by different soil management strategies     

Héctor Valdés-Gómez  Christian GaryPhilippe Cartolaro  Mauricio Lolas-CaneoAgnès Calonnec 《Crop Protection》2011,30(9):1168-1177

In various crop species, high levels of powdery mildew infection and severity have been associated with high vegetative vigour. In grapevine this relationship has also been observed by vine growers, though it has not been quantified. This study was undertaken to investigate the relationship between the development of powdery mildew on leaves and berries and canopy growth, and thus to quantify the relationship between the pathogen and its host. Over a two-year period (2005 and 2006), an experiment was carried out in a vineyard (cv. Aranel) near Montpellier, southern France. Several levels of canopy growth were generated by implementing four soil management strategies: i) perennial cover crop in the inter-row, ii) annual cover crop in the inter-row, iii) chemical weed control over the entire soil surface, iv) chemical weed control all over the soil surface and drip irrigation and fertilization in the row. Powdery mildew was artificially inoculated on experimental sub-plots with Erysiphe necator [Schw.] Burr. conidia. The most vigorous vines developed a larger number of diseased leaves and a higher percentage of mildewed berries compared to low-vigour vines. The major explanatory variable highlighted in these experiments was the shoot leaf number, mainly early in the season. A higher leaf population generated a larger number of powdery mildew colonies close to grapes and consequently a higher probability of berry infection. Our experimental results provide evidence of a positive relationship between powdery mildew development and grapevine vegetative development. These results provide an opportunity to develop new IPM strategies in vineyards.  相似文献   

Structural development of Pacific red snapper Lutjanus peru from hatching to the onset of first feeding          下载免费PDF全文

Iram Zavala‐Leal  Silvie Dumas  Edgar O. López‐Villegas  Renato Peña  Mauricio Contreras‐Olguín  Laura Flores‐Montijo  José De La Cruz‐Agüero 《Aquaculture Research》2015,46(5):1162-1174

Successful rearing of larval fish requires culture conditions and feeding strategies matching the ontogenetic status of larvae. This study describes the external morphology and development of organs and structures involved in the feeding process (i.e. sensorial organs, mouthparts and digestive system) from hatching until first feeding in Pacific red snapper. Hatching occurred 26 h after fertilization at 26°C and total length (TL) was 2.45 ± 0.08 mm. The larvae showed an undifferentiated eye and digestive tract. At 48 hah, TL was 3.31 ± 0.12 mm. Yolk and oil globule were still present. The mouth was still closed, but the Meckel's, quadrate, hyoid and hyomandibular cartilages were present. The retina was formed by 5 layers, and a thin layer of pigment epithelium was observed in the outer nuclear layer (ONL). At 70 hah, TL was 3.44 ± 0.22 mm. A remnant of oil globule was still present. The mouth and anus were open. At 93 hah, the number of cones in the ONL of the retina have increased and there was more pigment in the pigment epithelial layer. A joint between Meckel's and the quadrate cartilage and also a joint between the hyomandibular cartilage and the skull were present. The presence of live feed was detected in the digestive tract of these larvae. Based on these observations, the Pacific red snapper larvae is functional to start ingesting live feed between the 3rd and 4th day after hatching.  相似文献   

Evaluation of a decision support strategy for the control of powdery mildew,Erysiphe necator (Schw.) Burr., in grapevine in the central region of Chile          下载免费PDF全文

Héctor Valdés‐Gómez  Miguel Araya‐Alman  Carolina Pañitrur‐De la Fuente  Nicolás Verdugo‐Vásquez  Mauricio Lolas  César Acevedo‐Opazo  Christian Gary  Agnès Calonnec 《Pest management science》2017,73(9):1813-1821

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Foraging behavior of heifers with or without social models in an unfamiliar site containing high plant diversity     

Mauricio Velázquez-Martínez  Silvia López-Ortiz  Omar Hernández-Mendo  Pablo Díaz-Rivera  Sergio Pérez-Elizalde  Jaime Gallegos-Sánchez 《Livestock Science》2010,131(1):73-82

Grazing behavior, diet selection and weight gain of heifers (with or without social models) were assessed in an unfamiliar site containing high plant diversity. The study was performed within a tropical forest ecosystem containing a mixture of grass forb/herb, shrub and tree species. Ten inexperienced crossbred Bos taurus × Bos indicus heifers (7 ± 1 months old) were randomly assigned to one of two groups: naive or naive + social model (sm) and two experienced heifers (16 months old) were assigned to the second group. Naive heifers were bottle-nursed from days 2 to 90 after birth and began grazing at 1 month of age in tropical grass monocultures, while experienced animals had been foraging in sites containing a high diversity of plant species for 3 months prior to the study. Each group grazed in separate paddocks for a 12-week period during the rainy season, and animals were observed using focal sampling from 7:00 to 19:30 h to assess diet composition based on bite counts. Weight gain was assessed every 14 days. Paddocks contained from 1481 to 1789 kg/ha of herbaceous dry matter, enough to support the heifers throughout the study without affecting diet selection. Shrub and tree cover ranged from 55.2 to 58.4% across treatments. Bites per minute were adjusted to a log-scaled quadratic-plateau model and the curves showed no differences between treatments (P = 0.756). However, diet composition differed between groups (P < 0.001), with naive + sm heifers ingesting a greater proportion of trees (P < 0.001) and shrubs (P = 0.02), while naive heifers ingested more forb/herbs (P = 0.02); no difference in grass consumption was observed (P = 0.92). Heifers in both treatments consumed the same plant species (50 from 26 families). Over time, utilization of several plant species increased or decreased (P < 0.05), eventually leveling off for the remainder of the study. Although differences in diet composition were observed, they did not affect overall weight gain (117 and 113 g/day in the naive and naive + sm groups, respectively; P = 0.913). However, initial post-weaning weight loss was avoided in the naive + sm group. Social learning facilitates a higher use of shrubs and trees in tropical pastures containing a high diversity of plant species with different growth habits. As many plant species have high potential as forage, more effort should be placed on developing mechanisms to increase their dietary inclusion by cattle.  相似文献   

Chronic inhibition of endoplasmic reticulum calcium-release channels and calcium-ATPase lengthens the period of hepatic clock gene Per1     

Adrián Báez-Ruiz  Mauricio Díaz-Muñoz 《Journal of circadian rhythms》2011,9(1):1-10

Background

The Magel2 gene is most highly expressed in the suprachiasmatic nucleus of the hypothalamus, where its expression cycles in a circadian pattern comparable to that of clock-controlled genes. Mice lacking the Magel2 gene have hypothalamic dysfunction, including circadian defects that include reduced and fragmented total activity, excessive activity during the subjective day, but they have a normal circadian period. Magel2 is a member of the MAGE family of proteins that have various roles in cellular function, but the specific function of Magel2 is unknown.

Methods

We used a variety of cell-based assays to determine whether Magel2 modifies the properties of core circadian rhythm proteins.

Results

Magel2 represses the activity of the Clock:Bmal1 heterodimer in a Per2-luciferase assay. Magel2 interacts with Bmal1 and with Per2 as measured by co-immunoprecipitation in co-transfected cells, and exhibits a subcellular distribution consistent with these interactions when visualized by immunofluorescence. As well, Magel2 induces the redistribution of the subcellular localization of Clock towards the cytoplasm, in contrast to the nucleus-directed effect of Bmal1 on Clock subcellular localization.

Conclusion

Consistent with the blunted circadian rhythm observed in Magel2-null mice, these data suggest that Magel2 normally promotes negative feedback regulation of the cellular circadian cycle, through interactions with key core circadian rhythm proteins.  相似文献   

Foreword to the 23rd International WAAVP Conference     

Bulman GM 《Veterinary parasitology》2011,180(1-2):1

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实施产后健康监测 及时发现病牛     

郭志钢  郭爱珍 《中国奶牛》2011,(21):39-41

牛群健康的一个重要理念就是早发现早治疗,早发现甚至比治疗本身更重要。对于泌乳牛,更要强调这个观念,因为耽误治疗不仅会降低治愈率,而且会导致产奶量下降,影响繁殖性能,围产后期发生的疾病尤为如此。尽管实施产后健康监测使我们在产后牛管理上取得很大进步,但还是经常漏诊早期发病牛,导致延误治疗。  相似文献   

Assessment of the Nutritional Value of Traditional Vegetables from Southern Chile as Potential Sources of Natural Ingredients     

Opazo-Navarrete  Mauricio  Burgos-Díaz  César  Soto-Cerda  Braulio  Barahona  Tamara  Anguita-Barrales  Fresia  Mosi-Roa  Yohanna 《Plant foods for human nutrition (Dordrecht, Netherlands)》2021,76(4):523-532

Plant Foods for Human Nutrition - There is an increasing interest in consuming healthy foods motivated by the need of boosting the immune system naturally. In this sense, vegetables rich in...  相似文献   

巴西里贝拉山谷的秘密     

宋平 《中国花卉园艺》2008,(3):43-45

巴西的园艺业有一个鲜为人知的秘密：在圣保罗州（Saoaul）南端的几个城镇,集中了约323家观赏花卉种植者,其栽培总面积达800公顷,这几个城镇已成为圣保罗州花卉种植的主要地区。该地区位于里贝拉河与大西洋交汇的低洼处,有着特别的微气候,年均温度在24℃,相对湿度85％,犹如天然温室一样。  相似文献