COMPUTED TOMOGRAPHY OF THE PHARYNX IN A CLOSED VS. OPEN MOUTH POSITION

The pharynx is anatomically complex and evaluation can be difficult even with cross‐sectional imaging. Eight animals had computed tomography (CT) studies of the head performed with the mouth open and closed. The studies were anonymized and evaluated by four radiologists for visibility of six anatomic regions (dorsal wall of nasopharynx, lumen of nasopharynx, dorsal margin of the soft palate, ventral margin of the soft palate, oropharynx, and laryngopharynx) and for certainty of a normal or abnormal diagnosis of four different anatomic regions (nasopharynx, soft palate, oropharynx, and laryngopharynx). Mean visual scores differed significantly between mouth positions and were improved when the mouth was open. The ability of radiologists to classify anatomic regions as normal or abnormal vs. unsure also varied between mouth positions, and there was greater uncertainty when the mouth was closed. In addition, estimated volume of the air‐filled nasopharynx differed significantly as a function of mouth position and was greater when the mouth was open (mean=1.187 cm³, SE=0.177) vs. closed (mean=0.584 cm³, SE=0.116). Computed tomographic evaluation of the pharynx can be improved with the mouth open.     

Optimized biophysical model for Icelandic cod (Gadus morhua) larvae

A characteristic of biophysical models (BPM) is that they contain a number of parameters that are poorly known or only known within a range of possible values. This paper describes an efficient optimized BPM developed to simulate the Icelandic cod pelagic 0‐group survey data. The method is based on presenting the results as a probability density function (PDF) that a particle released from a given spawning drifts downstream to a given grid location some time later. The model determines egg production model parameters (peak spawning time, spawning duration, number of eggs released) for each of 15 spawning grounds as the solution of a bound constrained optimization problem that minimizes model‐data misfits in abundance and age distributions. The model is applied to simulating the 2002 and 2003 summer survey data. The model does a reasonable job of simulating the observed inshore / offshore abundance gradient and spatial age gradient for each year. Problem areas are explained from the point of view of model limitations. We caution that the results from an optimized model should always be assessed with the model’s limitations in mind and with respect to whatever biological data are available.     

Nesting Habitat Selection by Crested Tits Parus cristatus in a Pine Plantation

Habitats surrounding nest boxes used and not used by crestedtits were compared at Culbin Forest, a plantation composed largelyof Scots and Corsican pines. Crested tits preferred to nestin boxes where the trees were thinner (median d.b.h. 13.7 cm).Diameter was correlated with tree height and negatively correlatedwith tree density. The ideal nesting site for crested tits maytherefore be a combination of a large rotten stump (rare inpine plantations) in which to nest and surrounding cover ofmoderately-sized closely-space trees (rare in semi-natural pineforests).     

The Effects of Nitrogen Fertiliser at Different Rates and Times of Application on the Growth of Sitka Spruce in Upland Britain

At seven experiment sites in Scotland and northern England theeffects of different rates (0 to 150 kg N ha^–1) and seasonof nitrogen (N) fertiliser application on the height growthof Sitka spruce were examined. A comparison of urea and ammoniumnitrate was included to determine the most effective sourceof N. At each site, height and foliar nutrient concentrationswere measured. The sites chosen displayed different degrees of N-deficiencywhich was reflected in foliar N levels and height growth responses.The largest responses to application of N occurred at the mostdeficient sites and foliar N concentration of the untreatedcrop could be used to predict the likely magnitude of response.However, neither the season of application nor the differentfertilisers used had any effect on height growth.     

The Effects on Song-Bird Populations of Upland Afforestation with Spruce

1. Large coniferous plantations have been established widely inuplands previously used for rearing sheep and cattle, causingfundamental changes in the wild life of these areas.
2. Breedingsong-birds were censused in south-west Scotland onupland moorlandgrazed by sheep and in spruce plantations atdifferent stagesof growth.
3. The commonest song-bird species were meadow pipitand skylarkon unplanted areas, meadow pipit in establishmentplantation,willow warbler and wren in thicket, and goldcrest,chaffinchand wren in polestage and thinned plantations.
4. Totalsong-bird densities were 40–70 pairs km^–2on unplantedheather, 70–130 pairs km^–2 on unplantedgrass, 125–200pairs km^–2 on 6 year old trees, 230–290pairs km^–2on 12–14 year old trees, and 300–440pairs km^–2on trees over 20 years old. Bird species diversitywas alsogreatest in trees over 20 years old, with one exception.
5. Manybird species depend on unafforested moorland, but werenot censusedsince they are too sparsely distributed. Theirloss is to beset against the gain in numbers of smaller songbirds followingafforestation which was inferred from the studyplots. Fromthe standpoint of bird conservation, diverse foreststructureand the retention of some large unafforested uplandareas isadvocated.

     

Vascular Endothelial (VEGF) and Epithelial Growth Factor (EGF) as Well as Platelet‐Activating Factor (PAF) and Receptors are Expressed in the Early Pregnant Canine Uterus

The aim of this study was to investigate the course of expression of platelet‐activating factor (PAF), PAF‐receptor (PAF‐R), epidermal growth factor (EGF), EGF‐R, vascular endothelial growth factor (VEGF), VEGF‐R1 and VEGF‐R2 in uterine tissue during canine pregnancy. For this purpose, 20 bitches were ovariohysterectomized at days 10–12 (n = 10), 18–25 (n = 5) and 28–45 (n = 5) days after mating, respectively. The pre‐implantation group was proven pregnant by embryo flushing of the uterus after the operation, the others by sonography. Five embryo negative, that is, non‐pregnant, bitches in diestrus (day 10–12) served as controls. Tissue samples from the uterus (placentation sites and horn width, respectively) were excised and snap‐frozen in liquid nitrogen after embedding in Tissue Tec^®. Extraction of mRNA for RT‐PCR was performed with Tri‐Reagent. In the embryos, mRNA from all factors except VEGF was detected. In the course of pregnancy, significantly higher expression of PAF and PAFR as well as VEGF and VEGFR2 during the pre‐implantation stage than in all other stages and a strong upregulation of EGF during implantation were characteristic. The course of EGF was in diametrical opposition to the course of the receptor. These results point towards an increased demand for VEGF, EGF and PAF during the earliest stages of canine pregnancy.