521 research outputs found
Errors in transrectal ultrasonic planimetry of the prostate: Computer simulation of volumetric errors applied to a screening population
Three systemic errors in routine ultrasonic planimetric volume measurements of the prostate were assessed. A computer model using ellipsoids was used to simulate the step section technique and different forms of rotational movements of the prostate during planimetry. The planimetric volume was up to 12% smaller than the exact volume, depending on the degree of rotational movement, the shape, and the length of the ellipsoid. In vivo study of a screening popul
Ability to cause erythema migrans differs between Borrelia burgdorferi sensu lato isolates
Background: Lyme borreliosis is a tick-borne disease caused by Borrelia burgdorferi sensu lato. The variety of characteristic and non-specific clinical manifestations is partially explained by its genetic diversity. We investigated the ability of B. burgdorferi sl isolates to cause erythema migrans. Methods. The genetic constellation of isolates from ticks was compared to isolates found in erythema migrans. PCR and sequence analysis was performed on the plasmid-encoded ospC and the chromosomal 5S-23S rDNA spacer region (IGS). Results: Seven different B. burgdorferi sl genospecies were identified in 152 borrelia isolates from ticks and erythema migrans biopsies. B afzelii (51%) and B. garinii (27%) were the most common in ticks. From the 44 sequences obtained from erythema migrans samples 42 were B. afzelii, one B. garinii and one B. bavariensis. Significant associations with erythema migrans formation were found for four IGS and two ospC types. Five from 45 ospC types were associated with more than one genospecies. Conclusions: B. burgdorferi sl isolates differ in their propensity to cause erythema migrans. These differences were also found within genospecies. In other words, although B. afzelii was mostly associated with erythema migrans, some B. afzelii isolates had a low ability to cause erythema migrans. Our data further support the occurrence of plasmid exchange between borrelia genospecies under natural conditions
Experimental evidence for inherent Lévy search behaviour in foraging animals
Recently, Lévy walks have been put forward as a new paradigm for animal search and many cases have been made for its presence in nature. However, it remains debated whether Lévy walks are an inherent behavioural strategy or emerge from the animal reacting to its habitat. Here, we demonstrate signatures of Lévy behaviour in the search movement of mud snails (Hydrobia ulvae) based on a novel, direct assessment of movement properties in an experimental set-up using different food distributions. Our experimental data uncovered clusters of small movement steps alternating with long moves independent of food encounter and landscape complexity. Moreover, size distributions of these clusters followed truncated power laws. These two findings are characteristic signatures of mechanisms underlying inherent Lévy-like movement. Thus, our study provides clear experimental evidence that such multi-scale movement is an inherent behaviour rather than resulting from the animal interacting with its environmen
LOOP:A physical artifact to facilitate seamless interaction with personal data in everyday life
We investigated how a physical artifact could support seamless interaction with personal activity data in everyday life. We introduce LOOP (Figure 1), a physical artifact that changes its shape according to the activity data of the owner, providing an abstract visualization. This paper reports on the design process of LOOP that was informed by interviews and co-creation sessions with end users. We conclude with future work on the evaluation of the concept. This paper makes two main contributions. Firstly, LOOP is proposed as an example of an alternative approach to physically represent activity data. Secondly, the design process and rationale behind LOOP are presented as design knowledge
Connectivity in implicational maps:authors’ reply to 'The added value of the connectivity hypothesis for the map of parts of speech' by Caterina Mauri (2010)
Alinhamento interpessoal, representacional e morfossintático na Gramática Discursivo-Funcional
Este artigo se debruça sobre o mapeamento entre os Níveis Interpessoal, Representacional e Morfossintático da gramática, o chamado alinhamento, segundo o arcabouço da Gramática Discursivo-Funcional (GDF). Propõe uma tipologia das línguas baseada no que a sua organização morfossintática codifica: distinções pragmáticas (p.ex. em Tagalo), distinções semânticas (p.ex. em Achém), ou distinções inerentes à morfossintaxe (p.ex. em Inglês, Basco ou a língua Kham). A inclusão tanto do Sujeito como do Objeto e de línguas tanto acusativas como ergativas no tratamento do alinhamento morfossintático permitiu-nos abranger tipos tipologicamente mais variáveis e demonstrar o potencial da GDF para a análise contrastiva das línguas.<br>Within the framework of Functional Discourse Grammar (FDG), alignment concerns the relations between the Interpersonal, Representational and Morphosyntactic Levels of grammar. This article proposes a typology of languages based upon what we find to be encoded in their morphosyntactic organization: pragmatic distinctions (as in Tagalog), semantic distinctions (as in Acheh), or distinctions inherent to the morphosyntax (as in English, Basque and Kham). By including both subject and object, and both accusative and ergative languages in our treatment of morphosyntactic alignment, we provide a better coverage of typological variation and show the potential of FDG for cross-linguistic analysis
The inner centromere is a biomolecular condensate scaffolded by the chromosomal passenger complex.
The inner centromere is a region on every mitotic chromosome that enables specific biochemical reactions that underlie properties, such as the maintenance of cohesion, the regulation of kinetochores and the assembly of specialized chromatin, that can resist microtubule pulling forces. The chromosomal passenger complex (CPC) is abundantly localized to the inner centromeres and it is unclear whether it is involved in non-kinase activities that contribute to the generation of these unique chromatin properties. We find that the borealin subunit of the CPC drives phase separation of the CPC in vitro at concentrations that are below those found on the inner centromere. We also provide strong evidence that the CPC exists in a phase-separated state at the inner centromere. CPC phase separation is required for its inner-centromere localization and function during mitosis. We suggest that the CPC combines phase separation, kinase and histone code-reading activities to enable the formation of a chromatin body with unique biochemical activities at the inner centromere
Circulation of four Anaplasma phagocytophilum ecotypes in Europe.
BACKGROUND
Anaplasma phagocytophilum is the etiological agent of granulocytic anaplasmosis in humans and animals. Wild animals and ticks play key roles in the enzootic cycles of the pathogen. Potential ecotypes of A. phagocytophilum have been characterized genetically, but their host range, zoonotic potential and transmission dynamics has only incompletely been resolved.
METHODS
The presence of A. phagocytophilum DNA was determined in more than 6000 ixodid ticks collected from the vegetation and wildlife, in 289 tissue samples from wild and domestic animals, and 69 keds collected from deer, originating from various geographic locations in The Netherlands and Belgium. From the qPCR-positive lysates, a fragment of the groEL-gene was amplified and sequenced. Additional groEL sequences from ticks and animals from Europe were obtained from GenBank, and sequences from human cases were obtained through literature searches. Statistical analyses were performed to identify A. phagocytophilum ecotypes, to assess their host range and their zoonotic potential. The population dynamics of A. phagocytophilum ecotypes was investigated using population genetic analyses.
RESULTS
DNA of A. phagocytophilum was present in all stages of questing and feeding Ixodes ricinus, feeding I. hexagonus, I. frontalis, I. trianguliceps, and deer keds, but was absent in questing I. arboricola and Dermacentor reticulatus. DNA of A. phagocytophilum was present in feeding ticks and tissues from many vertebrates, including roe deer, mouflon, red foxes, wild boar, sheep and hedgehogs but was rarely found in rodents and birds and was absent in badgers and lizards. Four geographically dispersed A. phagocytophilum ecotypes were identified, that had significantly different host ranges. All sequences from human cases belonged to only one of these ecotypes. Based on population genetic parameters, the potentially zoonotic ecotype showed significant expansion.
CONCLUSION
Four ecotypes of A. phagocytophilum with differential enzootic cycles were identified. So far, all human cases clustered in only one of these ecotypes. The zoonotic ecotype has the broadest range of wildlife hosts. The expansion of the zoonotic A. phagocytophilum ecotype indicates a recent increase of the acarological risk of exposure of humans and animals
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