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231.
Henrique Meiroz de Souza Almeida Gabriel Yuri Storino Daniele Araújo Pereira Igor Renan Honorato Gatto Luis Antonio Mathias Hélio José Montassier Luís Guilherme de Oliveira 《Tropical animal health and production》2017,49(1):25-30
Swine influenza (SI) is a seasonal infectious disease highly important to the world pig industry. Loss of daily weight gain, increased costs for the prevention and treatment of secondary infections are the main economic losses associated with the presence of this disease. However, some epidemiological features of SI remain quite unclear. This study focused on assessing the prevalence of swine influenza virus (SIV) infection in intensive and extensive pig herds and associating risk factors. A set of 601 blood samples of five intensive farrow-to-finish farms and 361 blood samples from 56 extensive farms were analyzed using an indirect ELISA kit CIVTEST SUIS INFLUENZA®, Hipra (Amer, Spain), in order to detect anti-SIV antibodies. In total, 24.13 % of samples from intensive herds were positive, while no positive samples were detected in extensive rearing herds. Sow and weaning piglets had the highest prevalence values. In the intensive rearing system, occurrence of reproductive disorders and exposure to recently introduced animals were positively associated with the disease occurrence in swine herds. The findings highlight the importance of sows in the epidemiology of the disease and bring information about risk factors involved in the occurrence of swine influenza in intensive herds. 相似文献
232.
Octaviano Igor Yelome Kris Audenaert Sofie Landschoot Alexandre Dansi Wouter Vanhove Drissa Silue Patrick Van Damme Geert Haesaert 《Genetic Resources and Crop Evolution》2018,65(6):1615-1624
The main goal of this study is to gain insight into the relationship between the genetic profile of cultivated rice (Oryza spp.) accessions and their resistance to rice blast. Therefore, the genetic and phenotypic variability of a set of 350 cultivated rice accessions originating from Africa (Benin, Mali and Nigeria, Ivory Coast etc.) was examined. Seventy-seven fluorescent amplified fragment polymorphism (AFLP) markers were used to gain insight into the genetic variation and to classify the germplasm collection. In addition, the rice germplasm was assessed for its resistance to blast disease caused by Pyricularia oryzae in upland field conditions. Huge differences in responses of rice accessions to P. oryzae were observed, ranging from highly susceptible to highly resistant. Twelve percent of all accessions were highly resistant to P. oryzae. Based on their AFLP marker profile these highly resistant accessions could be separated from the other accessions. Stepwise regression revealed that the best prediction of the blast resistance level was achieved with a maximum number of 13 AFLP markers. Marker CTA22 was the most important for accurate prediction of blast resistance, this marker was present in all highly resistant accessions. It can be concluded that AFLP markers are a valuable tool to screen rice accessions for their susceptibility towards blast disease and that, based on a subset of markers, it is possible to predict the resistance to rice blast. 相似文献
233.
Effects of short-term thermomechanical densification on the structure and properties of wood veneers
Pavlo Bekhta Stanisław Proszyk Tomasz Krystofiak Jan Sedliacik Igor Novak Miroslava Mamonova 《Wood material science & engineering》2017,12(1):40-54
The effects of short-term thermomechanical (STTM) densification temperature and pressure on the changes in surface roughness, wettability, mass loss (ML), thickness and density of alder, beech, birch, and pine wood veneer with low moisture content (~5%) were investigated. The anatomical structure of veneers was also observed. Veneer sheets were densified using pressure levels of 4, 8 and 12 MPa at three temperatures: 100°C, 150°C and 200°C for 4 min. The results were compared with those of the non-densified veneers. The obtained results show that STTM densification of veneers similarly to long-term densification of solid wood causes irreversible changes in their properties. The STTM-densified veneer surfaces became smoother and more hydrophobic, ML increased slightly while roughness and thickness values decreased significantly, the cell lumens collapsed and a certain amount of fractures in cell walls developed with increasing densification temperature and pressure. All of the investigated wood species showed higher density values after densification. It was found that an even STTM densification of veneers provides stable properties under normal atmosphere conditions; in particular, the thickness and contact angle values were stable for 24 hours after densification, which is an important consideration for industrial applications. 相似文献
234.
Marcelo F. da Silva Rebeca S. de Araújo Diehgo T. da Silva Osimar Sanches Igor Hamoy Edilson Matos 《Journal of fish diseases》2019,42(6):905-912
Ninety‐seven specimens of spotfin hatchetfish, Thoracocharax stellatus, an ornamental freshwater species from the Amazon basin, were captured in the basin of the Guamá River in the municipality of Belém, in northern Brazil, and analysed for coccidiosis infection. Overall, 26 of the specimens were infected by apicomplexan parasites of the genus Goussia, with unsporulated forms being found in the gastric epithelium and sporulated forms in the intestinal lumen. The spheroid oocysts (mean diameter: 13.2 ± 1.7 μm) have four elliptical sporocysts. A partial sequence of the SSU rDNA of the new species was obtained, which contained 1,121 base pairs, with 43.8% guanine + cytosine (G + C), and the bases distributed as follows: A = 28.1%, C = 18.3%, G = 25.5% and T = 28.1%. The combined analysis of the morphometric and phylogenetic evidence confirmed that the specimens represented the genus Goussia and were allocated to a new species, Goussia guamaensis n. sp., which is described here. 相似文献
235.
Guillem Chust Nerea Goikoetxea Leire Ibaibarriaga Yolanda Sagarminaga Igor Arregui Almudena Fontn Xabier Irigoien Haritz Arrizabalaga 《Fisheries Oceanography》2019,28(5):505-516
Marine species have exhibited trends in their geographic distribution and phenology in recent decades, and these changes are triggered by climate variability or anthropogenic pressures. Northeast Atlantic albacore has recently been identified to show changes of this nature, although the underlying causes are still uncertain. The aim of this work was to analyse the Northeast Atlantic albacore distribution shifts and phenological changes during the trophic migration that juveniles undertake from late spring to autumn and to identify potential causes of such variability. Specifically, time series of albacore catches of the Basque trolling fleet were studied and compared with trends derived from a null ecological niche model using very large number of catch observations (27,982). The results showed an earlier albacore migration of 2.3 days per decade during the period of 1981–2017, which was partly associated with the recent warming of the sea. The trend analysis of the catch distribution also detected a significant north‐westward trend in catch observations and a northward trend in species habitat. In contrast, both latitudinal trends were uncorrelated. This result suggests that interannual species distribution shifts are mainly related to factors other than oceanic‐climatic variability, such as fleet behaviour or prey changes. 相似文献
236.
Igor Christo Miyahira Maria Cristina Dreher Mansur Luiz Eduardo Macedo de Lacerda Isabela Cristina Brito Gonçalves Glauco Gil Sant'Anna Sonia Barbosa dos Santos 《水产资源保护:海洋与淡水生态系统》2023,33(1):102-114
- Bivalves are important components of freshwater ecosystems; however, they are also one of the most threatened animal groups, especially members of the order Unionida. The main threats to freshwater bivalves are habitat modification and invasive species. Protected areas are a common way to minimize impacts and preserve native species, but they are rarely designated with a focus on freshwater invertebrates.
- The main goal of this article was to describe the distribution of freshwater bivalves in the state of Rio de Janeiro, and the relationship between these species and bioclimatic areas, land use and protected areas.
- Five native and two invasive bivalve species have been reported in Rio de Janeiro. They occur mainly in bioclimatic areas related to the Paraíba do Sul River and Campista Lowlands. The few records of bivalves inside protected areas are in areas of sustainable use that offer a lower level of protection, and frequently in sympatry with invasive bivalves.
- Thus, the established protected areas in Rio de Janeiro are not adequately effective for freshwater bivalve conservation, and some species remain under threat even within them. Freshwater bivalves thus remain largely unprotected in the state.
- The development of new protected areas and management plans should consider other faunal groups that are usually ignored, such as freshwater bivalves, to achieve more inclusive and effective protection.