Anthelmintic resistance of gastrointestinal cattle nematodes

Anthelmintic resistance of parasites in small ruminants, cattle and horses is increasing worldwide as a consequence of the over usage of the currently available products. In Belgium, Cooperia oncophora is the most common cattle nematode in which resistance, especially against macrocyclic lactones, occurs. Once resistance has been diagnosed, a change to another drug with a different mode of action is advised. However, effective anthelmintics will be hardly available in the near future. Therefore, it is important that farmers and veterinarians find a balance between achieving good parasite control and the sustainability of their control strategies. In this way, anthelmintic resistance may be delayed, and the effectiveness of anthelmintic drugs may be prolonged. This requires sensitive detection tools. With a sensitive detection technique, anthelmintic resistance can be diagnosed in a very early stage. Hence, the spread of resistance alleles in the parasite population may be prevented. In this review, different diagnostic assays for the detection of anthelmintic resistance are discussed, an overview is given of the current status of anthelmintic resistance in Belgian cattle, and measures are suggested to avoid or delay the development of anthelmintic resistance

Perceptual Grouping of Object Contours Survives Saccades

Human observers explore scenes by shifting their gaze from object to object. Before each eye movement, a peripheral glimpse of the next object to be fixated has however already been caught. Here we investigate whether the perceptual organization extracted from such a preview could guide the perceptual analysis of the same object during the next fixation. We observed that participants were indeed significantly faster at grouping together spatially separate elements into an object contour, when the same contour elements had also been grouped together in the peripheral preview display. Importantly, this facilitation occurred despite a change in the grouping cue defining the object contour (similarity versus collinearity). We conclude that an intermediate-level description of object shape persists in the visual system across gaze shifts, providing it with a robust basis for balancing efficiency and continuity during scene exploration

Dissipationless Spin Current between Two Coupled Ferromagnets

We demonstrate the general principle which states that a dissipationless spin current flows between two coupled ferromagnets if their magnetic orders are misaligned. This principle applies regardless the two ferromagnets are metallic or insulating, and also generally applies to bulk magnetic insulators. On a phenomenological level, this principle is analogous to Josephson effect, and yields a dissipationless spin current that is independent from scattering. The microscopic mechanisms for the dissipationless spin current depend on the systems, which are elaborated in details. A uniform, static magnetic field is further proposed to be an efficient handle to create the misaligned configuration and stabilize the dissipationless spin current.Comment: 10 pages, 5 figure

M & L Jaargang 33/5

Peter Van den Hove Halen 12 augustus 1914. Een vergeten strijd in een vergeten landschap? [Halen, August 12, 1914. A forgotten battle in a forgotten landscape?]Aan het begin van de oorlog, in augustus 1914, probeerde het Belgische leger in Halen nog moedig de vijand tegen te houden met inzet van ruiters en karabinier-wielrijders, uitgerust met plooifiets en met machinegeweren gemonteerd op hondenkarren. Al spoedig bekend geworden als de Slag der Zilveren Helmen, omdat men ten onrechte dacht dat de helmen van de Duitse cavalerie verzilverd waren, betekende deze prille oorlogsepisode ook meteen het einde van de hopeloos verouderde 19de-eeuwse oorlogsvoering. Peter Van den Hove wijst op tal van relicten in het landschap rond Halen die nog herinneren aan dit opmerkelijk gevecht en pleit met overtuiging voor de bescherming van dit fragiele oorlogserfgoed.Dries Vanhove Een veldhospitaalbarak uit de Eerste Wereldoorlog op het domein De Lovie in Poperinge. [A field hospital from World War I on the De Lovie domain in Poperinge.]De talloze gewonden tijdens Wereldoorlog I hadden nood aan voorlopige hospitaalaccommodaties dichtbij de frontzone. Houten barakken in handige bouwpakketten boden hier de perfecte oplossing. Na de oorlog werden sommige barakken hergebruikt of gedemonteerd en elders heropgebouwd, maar de meeste gingen verloren. Een veldhospitaalbarak van de Franse firma Hamon, nu opgesteld in het domein De Lovie in Poperinge, is één van de zeldzaam overgebleven relicten van deze efemere bouwsels, die de herinnering aan de Groote Oorlog levend houden. Ingenieur-architect Dries Vanhove bestudeerde de geschiedenis en de constructie van deze barakken en formuleerde op basis hiervan een weloverwogen restauratieplan.Rudy De Graef Omgaan met een modernistisch gebouw: de provinciale tuinbouwschool in Mechelen. [Dealing with a modernistic building: the provincial horticultural school in Mechelen.]De provinciale tuinbouwschool in Mechelen werd tussen 1928 en 1934 naar ontwerp van Jan Lauwers opgetrokken. De provincie Antwerpen beheert het gebouw. Het beheer evolueerde van onderhoud met ad-hoc herstellingen naar een meer systematische preventieve conservatie. Rudy De Graef schetst het verloop van dit proces en beschrijft de uitwerking van het masterplan en de resultaten van het onderzoek, proefrestauraties en de eerste restauratiefase. Deze casestudy is interessant voor lokale en regionale besturen die geconfronteerd worden met het beheer van monumentale bouwwerken.Summar

Transcriptome analyses reveal protein and domain families that delineate stage-related development in the economically important parasitic nematodes, Ostertagia ostertagi and Cooperia oncophora

BACKGROUND: Cooperia oncophora and Ostertagia ostertagi are among the most important gastrointestinal nematodes of cattle worldwide. The economic losses caused by these parasites are on the order of hundreds of millions of dollars per year. Conventional treatment of these parasites is through anthelmintic drugs; however, as resistance to anthelmintics increases, overall effectiveness has begun decreasing. New methods of control and alternative drug targets are necessary. In-depth analysis of transcriptomic data can help provide these targets. RESULTS: The assembly of 8.7 million and 11 million sequences from C. oncophora and O. ostertagi, respectively, resulted in 29,900 and 34,792 transcripts. Among these, 69% and 73% of the predicted peptides encoded by C. oncophora and O. ostertagi had homologues in other nematodes. Approximately 21% and 24% were constitutively expressed in both species, respectively; however, the numbers of transcripts that were stage specific were much smaller (~1% of the transcripts expressed in a stage). Approximately 21% of the transcripts in C. oncophora and 22% in O. ostertagi were up-regulated in a particular stage. Functional molecular signatures were detected for 46% and 35% of the transcripts in C. oncophora and O. ostertagi, respectively. More in-depth examinations of the most prevalent domains led to knowledge of gene expression changes between the free-living (egg, L1, L2 and L3 sheathed) and parasitic (L3 exsheathed, L4, and adult) stages. Domains previously implicated in growth and development such as chromo domains and the MADF domain tended to dominate in the free-living stages. In contrast, domains potentially involved in feeding such as the zinc finger and CAP domains dominated in the parasitic stages. Pathway analyses showed significant associations between life-cycle stages and peptides involved in energy metabolism in O. ostertagi whereas metabolism of cofactors and vitamins were specifically up-regulated in the parasitic stages of C. oncophora. Substantial differences were observed also between Gene Ontology terms associated with free-living and parasitic stages. CONCLUSIONS: This study characterized transcriptomes from multiple life stages from both C. oncophora and O. ostertagi. These data represent an important resource for studying these parasites. The results of this study show distinct differences in the genes involved in the free-living and parasitic life cycle stages. The data produced will enable better annotation of the upcoming genome sequences and will allow future comparative analyses of the biology, evolution and adaptation to parasitism in nematodes

Correlations Between Gene Expression and Mercury Levels in Blood of Boys With and Without Autism

Gene expression in blood was correlated with mercury levels in blood of 2- to 5-year-old boys with autism (AU) compared to age-matched typically developing (TD) control boys. This was done to address the possibility that the two groups might metabolize toxicants, such as mercury, differently. RNA was isolated from blood and gene expression assessed on whole genome Affymetrix Human U133 expression microarrays. Mercury levels were measured using an inductively coupled plasma mass spectrometer. Analysis of covariance (ANCOVA) was performed and partial correlations between gene expression and mercury levels were calculated, after correcting for age and batch effects. To reduce false positives, only genes shared by the ANCOVA models were analyzed. Of the 26 genes that correlated with mercury levels in both AU and TD boys, 11 were significantly different between the groups (P(Diagnosis*Mercury) ≤ 0.05). The expression of a large number of genes (n = 316) correlated with mercury levels in TD but not in AU boys (P ≤ 0.05), the most represented biological functions being cell death and cell morphology. Expression of 189 genes correlated with mercury levels in AU but not in TD boys (P ≤ 0.05), the most represented biological functions being cell morphology, amino acid metabolism, and antigen presentation. These data and those in our companion study on correlation of gene expression and lead levels show that AU and TD children display different correlations between transcript levels and low levels of mercury and lead. These findings might suggest different genetic transcriptional programs associated with mercury in AU compared to TD children