Sequence characterisation and expression of homeobox HOX A7 in the multi-potential erythroleukaemic cell line TF-1

Homeobox gene expression was examined in the erythroleukaemic cell line TF-1. Expression of a number of HOX A, B and C genes, including HOX A7 was detected. Expression of this gene has not previously been reported in erythroleukaemic cell lines. A 2.1 kb full length cDNA of the HOX A7 gene was cloned. The predicted amino acid sequence C-terminal to the homeodomain consists of an alanine-rich region and a strongly negatively charged domain consisting entirely of aspartic and glutamic acid residues.

Measurement and modelling of perceived slant in surfaces represented by freely viewed line drawings

Simple pictures under everyday viewing conditions evoke impressions of surfaces oriented in depth. These impressions have been studied by measuring the slants of perceived surfaces, with probes (rotating arrowheads) designed to respect the distinctive character of depicted scenes. Converging arguments indicated that the perceived orientation of the probes was near theoretical values. A series of experiments showed that subjects formed well-defined impressions of depicted surface orientation. The literature suggests that perceived objects might be flattened', but that was not the general rule. Instead, both mean slant and uncertainty fitted models in which slant estimates are derived in a relatively straightforward way from local relations in the picture. Simplifying pictures tended to make orientation estimates less certain, particularly away from the natural anchor points (vertical and horizontal). The shape of the object affected all aspects of the observed-object/percept relationship. Individual differences were large, and suggest that different individuals used different relationships as a basis for their estimates. Overall, data suggest that everyday picture perception is strongly selective and weakly integrative. In particular, depicted slant is estimated by finding a picture feature which will be strongly related to it if the object contains a particular regularity, not by additive integration of evidence from multiple directly and indirectly relevant sources.

Variation among nonclinical subjects on a line-bisection task

Absence of leftward bias in a line bisection task is often used as a clinical hemispheric indicator, but the effect is not uniform in a normal population. Sex, handedness, and strategy variables affect the strength and direction of any bias.

FROM LINE-DRAWINGS TO IMPRESSIONS OF 3D OBJECTS - DEVELOPING A MODEL TO ACCOUNT FOR THE SHAPES THAT PEOPLE SEE

The interpretations people attach to line drawings reflect shape-related processes in human vision. Their divergences from expectations embodied in related machine vision traditions are summarized, and used to suggest how human vision decomposes the task of interpretation. A model called IO implements this idea. It first identifies geometrically regular, local fragments. Initial decisions fix edge orientations, and this information constrains decisions about other properties. Relations between fragments are explored, beginning with weak consistency checks and moving to fuller ones. IO's output captures multiple distinctive characteristics of human performance, and it suggests steady progress towards understanding shape-related visual processes is possible.

Detection of Voigt Spectral Line Profiles of Hydrogen Radio Recombination Lines toward Sagittarius B2(N)

We report the detection of Voigt spectral line profiles of radio recombination lines (RRLs) toward Sagittarius B2(N) with the 100 m Green Bank Telescope (GBT). At radio wavelengths, astronomical spectra are highly populated with RRLs, which serve as ideal probes of the physical conditions in molecular cloud complexes. An analysis of the Hn alpha lines presented herein shows that RRLs of higher principal quantum number (n > 90) are generally divergent from their expected Gaussian profiles and, moreover, are well described by their respective Voigt profiles. This is in agreement with the theory that spectral lines experience pressure broadening as a result of electron collisions at lower radio frequencies. Given the inherent technical difficulties regarding the detection and profiling of true RRL wing spans and shapes, it is crucial that the observing instrumentation produce flat baselines as well as high-sensitivity, high-resolution data. The GBT has demonstrated its capabilities regarding all of these aspects, and we believe that future observations of RRL emission via the GBT will be crucial toward advancing our knowledge of the larger-scale extended structures of ionized gas in the interstellar medium (ISM).

Porcine Circovirus Type 2 Morphogenesis in a Clone Derived from the L35 Lymphoblastoid Cell Line

Porcine circovirus type 2 (PCV2) is the essential infectious agent of post-weaning multisystemic wasting syndrome (PMWS), one of the most important diseases of swine. Although several studies have described different biological properties of the virus, some aspects of its replication cycle, including ultrastructural alterations, remain unknown. The aim of the present study was to describe for the first time a complete morphogenesis study of PCV2 in a clone of the lymphoblastoid L35 cell line at the ultrastructural level using electron microscopy techniques. Cells were infected with PCV2 at a multiplicity of infection of 10 and examined at 0, 6, 12, 24, 48, 60 and 72 h post-infection. PCV2 was internalized by endocytosis, after which the virus aggregated in intracytoplasmic inclusion bodies (ICIs). Subsequently, PCV2 was closely associated with mitochondria, completing a first cytoplasmic phase. The virus entered the nucleus for replication and virus assembly and encapsidation occurred with the participation of the nuclear membrane. Immature virions left the nucleus and formed ICIs in a second cytoplasmic phase. The results suggest that at the end of the replication cycle (between 24 and 48 h), PCV2 was released either by budding of mature virion clusters or by lysis of apoptotic or dead cells. In conclusion, the L35-derived clone represents a suitable in-vitro model for PCV2 morphogenesis studies and characterization of the PCV2 replication cycle. (C) 2010 Elsevier Ltd. All rights reserved.

Nonlinear Field Line Random Walk and Generalized Compound Diffusion of Charged Particles

A new nonlinear theory for the perpendicular transport of charged particles is presented. This approach is based on an improved nonlinear treatment of field line random walk in combination with a generalized compound diffusion model. The generalized compound diffusion model is much more systematic and reliable, in comparison to previous theories. Furthermore, the new theory shows remarkably good agreement with test-particle simulations and heliospheric observations.

Electron refluxing and K-shell line emission from Ti foils irradiated with sub-picosecond laser pulses at 527nm

We present data on emission of K-shell radiation from Ti foils irradiated with subpicosecond pulses of second harmonic radiation (527 nm) from the TARANIS laser system at intensities of up to 1018 Wcm-2. The data are used to demonstrate that a resonance absorption type mechanism is responsible for absorption of the laser light and to estimate fast electron temperatures of 30–60 keV that are in broad agreement with expectation from models of absorption for a steep density gradient. Data taken with resin-backed targets are used to demonstrate clear evidence of electron refluxing even at the modest fast electron temperatures inferred.

Emergency slaughter of casualty cattle increases the prevalence of anthelmintic drug residues in muscle

The ProSafeBeef project studied the prevalence of residues of anthelmintic drugs used to control parasitic worms and fluke in beef cattle in Ireland. Injured (casualty) cattle may enter the human food chain under certain conditions, verified by an attending veterinarian and the livestock keeper. An analytical survey was conducted to determine if muscle from casualty cattle contained a higher prevalence of anthelmintic drug residues than healthy (full slaughter weight) cattle as a result of possible non-observance of complete drug withdrawal periods. A validated analytical method based on matrix solid-phase dispersive extraction (QuEChERS) and ultra-performance liquid chromatography-tandem mass spectrometry was used to quantify 37 anthelmintic drugs and metabolites in muscle (assay decision limits, CCa, 0.15-10.2 µg kg -1). Of 199 control samples of beef purchased in Irish shops, 7% contained detectable anthelmintic drug residues but all were compliant with European Union Maximum Residue Limits (MRL). Of 305 muscle samples from injured cattle submitted to abattoirs in Northern Ireland, 17% contained detectable residues and 2% were non-compliant (containing either residues at concentrations above the MRL or residues of a compound unlicensed for use in cattle). Closantel and ivermectin were the most common residues, but a wider range of drugs was detected in muscle of casualty cattle than in retail beef. These data suggest that specific targeting of casualty cattle for testing for anthelmintic residues may be warranted in a manner similar to the targeted testing for antimicrobial compounds often applied in European National Residues Surveillance Schemes. © 2012 Copyright Taylor and Francis Group, LLC.