A total of 1379 beef bull pictures were surveyed to determine visibility of feet and legs from four American semen company websites. Five different breeds were represented: Angus, Red Angus, Hereford ...(polled and horned), Simmental, and Charolais. In addition to visibility, data on other variables were collected to establish frequencies and correlations. These included breed, color, material that obscured visibility, such as grass, picture taken at livestock show or outside, semen company, photographer, video, and age of bull. A foot and leg visibility score was given to each bull picture. Only 19.4% of the pictures had fully visible feet and legs. Both the hooves and dewclaws were hidden on 32.5% of the pictures. Correlation between bull's birthdate and the first four visibility scores was statistically significant (P < 0.0001). As age increased the feet and legs were more likely to be visible in the bull's picture. This may possibly be due to greater availability of both photo editing software and digital photography. One positive finding was that 6% of the bulls had a video of the bull walking which completely showed his feet and legs.
A variety of techniques exists to analyse the size and size distribution of nanoparticles in a suspension. However, these nanoparticle characterisation methods have been rarely fully validated and ...appropriate reference materials with properly assigned SI traceable values are not easily found. This paper presents results of in-house validation studies of Dynamic Light Scattering (DLS) and Centrifugal Liquid Sedimentation (CLS) methods. During these studies, a silica nanoparticle reference material was tested under repeatability and intermediate precision conditions. The trueness of the DLS and CLS methods was investigated by measuring gold and polystyrene nanoparticle reference materials. Furthermore, for each method, an uncertainty budget has been established. Both method validation and estimation of reliable measurement uncertainties are prerequisites for the certification of new nanoparticle reference materials.
•A randomised phase II trial of radiotherapy dose escalation for pain control in MPM.•Comparison of 2 hypofractionated regimes (20 Gy/5# and 36 Gy/6#).•Highly conformal radiotherapy techniques used ...to aid safe dose escalation.•Primary outcome: pain control at week 5 at radiotherapy site.•Recruitment target: 112 patients from 10 to 15 UK centres.
SYSTEMS-2 is a randomised study of radiotherapy dose escalation for pain control in 112 patients with malignant pleural mesothelioma (MPM). Standard palliative (20 Gy/5#) or dose escalated treatment (36 Gy/6#) will be delivered using advanced radiotherapy techniques and pain responses will be compared at week 5. Data will guide optimal palliative radiotherapy in MPM.
Variability in the size of single postsynaptic responses is a feature of most central neurons, although the source of this variability is not completely understood. The dominant source of variability ...could be either intersynaptic or intrasynaptic. To quantitatively examine this question, a biophysically realistic model of an idealized central axospinous synapse was used to assess mechanisms underlying synaptic variability measurements. Three independent sources of variability were considered: stochasticity of postsynaptic receptors ("channel noise"), variations of glutamate concentration in the synaptic cleft (Deltaq), and differences in the potency of vesicles released from different locations on the active zone release-location dependence (RLD). As expected, channel noise was small (8% of the total variance) and Deltaq was the dominant source of variability (58% of total variance). Surprisingly, RLD accounted for a significant amount of variability (36%). Our simulations show that potency of release sites decreased with a length constant of approximately 100 nm, and that receptors were not activated by release events >300 nm away, which is consistent with the observation that single active zones are rarely >300 nm. RLD also predicts that the manner in which receptors are added or removed from synapses can dramatically affect the nature of the synaptic response, with increasing receptor density being more efficient than merely increasing synaptic area. Saturation levels and synaptic geometry were also important in determining the size and shape of the distribution of amplitudes recorded at different synapses.
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