Suchergebnisse

In Europe, species of the nematode genus Bursaphelenchus have been known and studied for a long time (Fuchs 1937; Ruhm 1956). Earlier, except from a purely biological or ecological point of view, no particular interest was paid to this group of mycophagous nematodes. In 1979, however, a study conducted in southwestern France showed that the nematode Bursaphelenchus lignicolous was associated with declining pines (Baujard et al. 1979). This report caused alarm in Europe, since B. lignicolous is a synonym of B. xylophilus ; the nematode in question was later identifi ed as B. mucronatus (De Guiran et al. 1986), which had been described as a new species that year. In 1984, a shipment of wood from North America to Finland was found to carry the pine wood nematode (PWN), B. xylophilus (Rautapaa 1986). This important interception prompted European authorities to develop more rigorous inspections at sea ports, and in particular of wood products coming from North America. However, no equivalent emphasis was placed on such products coming from East Asia. Between 1996 and 1999, an EU-funded project (RISKBURS) resulted in an updated survey of the Bursaphelenchus species in Europe (European Communities 2003). For an updated situation on the species distribution in the EU, see Braasch (2001). In 1999, the PWN, the causal agent of pine wilt disease, was fi rst detected in the European Union (EU), in Portugal (Mota 2004; Mota et al. 1999), and this immediately prompted several national and EU governments to assess the extent of the nematode's distribution, and to restrict B. xylophilus and its insect vector (Monochamus galloprovincialis ) to an area with a 30-km radius in the Setúbal Peninsula, 20 km south of Lisbon (Rodrigues 2007). The origin of the population of PWN found in Portugal remains unknown, although recent research indicates that it originated from Eastern Asia (Vieira et al. 2007). Several hypotheses have been suggested on how it entered the country, namely from North America or from Japan or China. World trade of wood products such as timber, wooden crates, and palettes play an important role in the potential dissemination of the PWN (Evans et al. 1996). In fact, human activities involving the movement of wood products may be the single most important factor in PWN spread. Despite the dedicated and concerted actions of government agencies, both the PWN and pine wilt disease continue to spread. In 2006 in Portugal, forestry and plant quarantine authorities (DGRF and DGPC) announced a new strategy for managing the problem. The plan is to establish a phytosanitary strip, 3-km wide, devoid of Pinus pinaster , surrounding the affected area, for the control and ultimately the eradication of the nematode, under the coordination of the national program for the control of the PWN (DGRF 2006). Research on the bioecology of the nematode and its insect vector, new detection methods, for example, involving real-time PCR, tree ecology and pathology, and control methods, has been underway since 1999. As well there are two major ongoing projects for the European Union (EU): PHRAME (http://www.forestresearch.gov.uk/website/forestresearch. nsf/ByUnique/INFD-63KGEF) and PortCheck (http://www.portcheck.eu.com/ index.cfm). This research has been instrumental in helping to understand the scientifi c aspects of pine wilt disease. The objective of the present paper is to highlight the progress made in Portugal and the EU. International agreements (GATT, WTO) and sharing of scientifi c information is of paramount importance for achieving effective control of the nematode and its vector, and in turn protection of our forest ecosystems and forest economies.

The pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD), is a serious pest and pathogen of forest tree species, in particular among the genus Pinus. It was first reported from Japan in the beginning of the XXth century, where it became the major ecological catastrophe of pine forests, with losses reaching over 2 million m3/ year in the 1980s. It has since then spread to other Asian countries such as China, Taiwan and Korea, causing serious losses and economic damage. In 1999, the PWN was first detected in the European Union (EU), in Portugal, and immmediately prompted several government (national and EU) actions to assess the extent of the nematode's presence, and to contain B. xylophilus and its insect vector (Monochamus galloprovincialis) to an area with a 30km radius in the Setúbal Peninsula, 20 km south of Lisbon. International wood trade, with its political as well as economic ramifications, has been seriously jeopardized. The origin of the population of PWN found in Portugal remains elusive. Several hypotheses may be considered regarding pathway analysis, basically from two general origins: North America or the Far East (Japan or China). World trade of wood products such as timber, wooden crates, palettes, etc… play an important role in the potential dissemination of the pinewood nematode. In fact, human activities involving the movement of wood products may be considered the single most important factor in spreading of the PWN. Despite the dedicated and concerted actions of government agencies, this disease continues to spread. Very recently (2006), in Portugal, forestry and phytosanitary authorities (DGRF and DGPC) have announced a new strategy for the control and ultimately the erradication of the nematode, under the coordination of the national program for the control of the pinewood nematode (PROLUNP). Research regarding the bioecology of the nematode and insect as well as new detection methods, e.g., involving real-time PCR, has progressed since 1999. International agreements (GATT, WTO) and sharing of scientific information is of paramount importance to effectively control the nematode and its vector, and thus protect our forest ecosystems and forest economy.

According to the European Plant Protection Organization, the pinewood nematode (PWN), Bursaphelenchus xylophilus is a quarantine organism at the top of the list of the pathogenic species. PWN may be found in North America (Canada, USA and Mexico) and in East Asia (Japan, Korea, China and Taiwan) and has a highly destructive capability towards conifers, in a relatively short time, causing serious economic damage in Japan, China and Korea. This nematode surveying is extremely important and a correct identification of nematode species associated with conifers is essential. Several conifers species are very susceptible (Pinus sylvestris, Pinus nigra and Pinus pinaster), the last one (maritime pine) is a particulary important economic specie in Portugal, and in southern Europe. In 1999, this nematode was found and identified for the first time in Portugal and in Europe. During 1999 and 2000, the Portuguese government, following an alert provided to European Community officials initiated an extensive national survey. During 2000 and 2001, research has been carried out regarding the morphobiometric as well as molecular (DNA: ITS-RFLP) characterization of the collected populations, as well as closely related species of Bursaphelenchus. The book details the Proceedings of an international workshop held at the University of Évora in 2001, covering all major aspects of the bioecology of the pinewood nematode (PWN), Bursaphelenchus xylophilus, its insect vectors and effects on the tree. Topics covered are: global issues and national surveys; morphology and molecular methods of identification of PWN; ecology and epidemiology; quarantine issues; tree physiology, resistance and histopathology; biology of PWN and relationships to its cerambycid vectors; control methods. General quarantine and political views are also presented.

The purpose of this study was to examine the relationship between motivation and burnout among Portuguese dual career athletes, and moderating role of negative career thoughts in the relationship between both. A total of 187 student-athletes, playing various sports, participated in the study and completed questionnaires on motivation, burnout and negative thoughts about their careers. Moderation effects were tested using linear regression models. The results indicated that there was a negative association between motivation and burnout and a moderating effect of anxiety and decision insecurity on the relationship between motivation and burnout. Understanding these variables is essential for the development of career intervention programs suitable for dual career of student-athletes.

The root lesion nematode (RLN) Pratylenchus penetrans is a migratory species that attacks a broad range of crops. After the RLN is initially attracted to host roots by root exudates and compounds, it releases secretions that are critical for successful parasitism. Among those secretions are nematode virulence factors or effectors that facilitate the entry and migration of nematodes through the roots and modulate plant immune defenses. The recognition of the effectors by host resistance proteins leads to effector-triggered immunity and incompatible plant- nematode interactions. Although many candidate effectors of the RLN and other plant-parasitic nematodes have been identified, the detailed mechanisms of their functions and particularly, their host targets remain largely unexplored. In this study, we sequenced and annotated genes encoding expansin-like proteins, which are major candidate effectors of P. penetrans. One of the genes, Pp-EXPB1, which was the most highly expressed during nematode infection in different plant species, was further functionally characterized via transient expression in the model plant Nicotiana benthamiana and global transcriptome profiling of gene expression changes triggered by this candidate effector in plants. As a result of this investigation, the biological roles of Pp-EXPB1 in nematode parasitism were proposed, the putative cellular targets of the proteins were identified, and the molecular mechanisms of plant responses to the nematode-secreted proteins were outlined. ; U.S. Department of AgricultureAgricultural Research Service grant CRIS [8042-21000-300-00D] ; This project was supported by U.S. Department of AgricultureAgricultural Research Service grant CRIS #8042-21000-300-00D. ; Public domain authored by a U.S. government employee

The root lesion nematode Pratylenchus penetrans is a migratory species that attacks a broad range of plants. While analysing transcriptomic datasets of P. penetrans, we have identified a full-length genome of an unknown positive-sense singlestranded RNA virus, provisionally named root lesion nematode virus 1 (RLNV1). The 8614-nucleotide genome sequence encodes a single large polyprotein with conserved domains characteristic for the families Picornaviridae, Iflaviridae and Secoviridae of the order Picornavirales. Phylogenetic, BLAST and domain search analyses showed that RLNV1 is a novel species, most closely related to the recently identified sugar beet cyst nematode virus 1 and potato cyst nematode picornalike virus. In situ hybridization with a DIG-labelled DNA probe confirmed the presence of the virus within the nematodes. A negative-strand-specific RT-PCR assay detected RLNV1 RNA in nematode total RNA samples, thus indicating that viral replication occurs in P. penetrans. To the best of our knowledge, RLNV1 is the first virus identified in Pratylenchus spp. ; United States Department of Agriculture, Agricultural Research ServiceUnited States Department of Agriculture (USDA) ; This research was supported by the United States Department of Agriculture, Agricultural Research Service. ; Public domain authored by a U.S. government employee

Se pretende hacer un acercamiento y analizar las convergencias y tensiones presentes en las relaciones entre los distintos grupos étnicos y raciales en el Brasil contemporáneo. El texto se basó en el análisis del pensamiento de Florestan Fernandes y del Movimiento Negro, así como en los acontecimientos de los años sesenta y setenta, cuya importancia radica en los nuevos abordajes teóricos para los temas de la emancipación, la desigualdad, la diferencia y la democracia. Tales perspec-tivas parecen estar enraizadas en las polémicas que han posibilitado la elaboración de críticas y la inžexión al interior del pensamiento social brasileño.

Se pretende hacer un acercamiento y analizar las convergencias y tensiones presentes en las relaciones entre los distintos grupos étnicos y raciales en el Brasil contemporáneo. El texto se basó en el análisis del pensamiento de Florestan Fernandes y del Movimiento Negro, así como en los acontecimientos de los años sesenta y setenta, cuya importancia radica en los nuevos abordajes teóricos para los temas de la emancipación, la desigualdad, la diferencia y la democracia. Tales perspec-tivas parecen estar enraizadas en las polémicas que han posibilitado la elaboración de críticas y la inžexión al interior del pensamiento social brasileño.