Does matrix resistance influence Red squirrel (Sciurus vulgaris L. 1758) distribution in an urban landscape?

In determining isolation effects in fragmented populations, the landscape matrix is not often considered. Usually simple distance measures are used to quantify degree of isolation. We tested the effect of the matrix on the presence of red squirrels in 354 wooded patches in the Brussels Region, by comparing several isolation measures. These were 1) distance to the nearest source patch, 2) the Hanski-measure (a combination of distance to and size of all possible sources), 3) effective distances calculated from different least cost models using the ArcView grid extension ‘Cost Distance’ (a combination of distance and resistance of the landscape, with different resistances for different landscape types) and 4) some combinations of the Hanski-measure and the effective distances. Size and quality of the target patches were always included in the tests of the predictive power of different isolation measures on squirrel presence/absence. All variables examined (patch size, quality and isolation) significantly influenced squirrel presence. Models using the effective distances gave the best results. Models including the Hanski-measure improved significantly when Euclidean distance was replaced by effective distance, showing that parameterisation of matrix resistance added significant additional explanatory power when modelling squirrel presence. This revised version was published online in July 2006 with corrections to the Cover Date.     

Blastomycosis in nondomestic felids.

Blastomycosis was diagnosed in six nondomestic felids from eastern Tennessee, including two Asian lions (Panthera leo persicus), one African lion (Panthera leo), one Siberian tiger (Panthera tigris), one cheetah (Acinonyx jubatus), and one snow leopard (Panthera uncia). Clinical signs included lethargy, anorexia, weight loss, dyspnea, sneezing. ataxia, and paresis. Variable nonspecific changes included leukocytosis, monocytosis, moderate left shift of neutrophils, moderate hypercalcemia, hyperproteinemia, and hyperglobulinemia. Thoracic radiographs revealed interstitial and alveolar changes, consolidation or collapse of a lung lobe, bullae formation, and a pulmonary mass. Agar gel immunodiffusion (AGID) serology for Blastomyces dermatitidis was performed in five felids and was positive in three. The tiger had cerebral blastomycosis and was positive for AGID serologic tests of both cerebrospinal fluid and serum. One percutaneous lung aspirate in the snow leopard and one bronchial aspirate in an Asian lion demonstrated B. dermatitidis organisms. whereas tracheal wash samples and a nasal discharge were nondiagnostic in others. Treatment with itraconazole was attempted in four cats. The tiger improved before euthanasia, whereas the others did not survive beyond initial treatments. In four felids, B. dermatitidis was found in the lungs and tracheobronchial lymph nodes associated with a florid pyogranulomatous reaction; the tiger had a pyogranulomatous encephalomyelitis, and the cheetah had a single pulmonary granuloma. Thoracic radiography, cytologic examination of lung lesion aspirates, and B. dermatitidis AGID serology should be performed on clinically ill zoo felids in endemic areas to rule out blastomycosis.     

Some physiological effects of spider mite infestation on bean plants

Using autoradiography it was shown that saliva ofT. urticae injected into the plant was transported to the growing regions. Indications were found that the two-spotted spider mite has an active phosphate metabolism. A local mite infestation on a bean plant caused an increased transport of phosphates to the top leaves and the roots.At the same time an increase of P transport towards the infested leaf was ascertained. It appeared that this was not caused by a wound reaction but by a physiological influence of the mite via their saliva secretion into the host plant. A mite population in bean interferes with the equilibrium of the growth promoting substances present in the plant. Under certain conditions a slight infestation of mites (1–4 per cm²) causes a growth stimulation. A heavier infestation (more than 10 per cm²) causes growth inhibition. Using thin layer chromatography an indole compound was found in the mites. In bean plants infested with mites the amount of gibberellin appeared to be markedly increased.Samenvatting Met behulp van autoradiografie werd aangetoond dat speekset van de bonespintmijt of bepaalde componenten van dat speeksel, welke tijdens de voedselopname in de plant (boon) worden gebracht, getransporteerd worden naar de sterk groeiende delen van de plant te weten de zich ontwikkelende bladeren en de wortel, (Fig. 1). Eenzelfde verdelingspartroon werd verkregen door autoradiografie van boneplanten die radioactief fosfaat hadden opgenomen via de bladsteel van een primair blad, (Fig. 2B). Het bleek dat reeds zes uur na het opnemen van voedsel, fosfaat, afkomstig van dat voedsel, in nieuw gevormde eieren kon worden teruggevonden, (Fig. 4). Een lokale mijtenaantasting van de boon veroorzaakt een toename van het fosfaattransport naar de top en de wortels, (Fig. 3).Tevens ontstaat er een fosfaattransport naar het aangetaste blad. Met behulp van behandeling van bladeren met carborundumpoeder kon aannemelijk worden gemaakt dat het hier gen wondreactie betreft maar er sprake is van een fysiologische reactie van de plant op een mijtenaantating. Een mijtenpopulaties verstoort het groeistoffenevenwicht in de plant. Een geringe aantasting (1–4 per cm² bladoppervlak) veroorzaakt onder bepaalde omstandigheden een stimulering van de lengtegroei van de plant en van de bladeren, (Fig. 5). Tevens wordt de wortelgroei gestimuleerd en wordt door het versneld uitlopen van de zijknoppen, de apicale dominantie doorbroken.Deze effecten treden vooral op in voorjaar en zomer wanneer de groei van de plant relatief het sterkst is. Het stimulerend effect kwam vooral tot uiting in de lengtegroei van de plant en de groei van het eerste samengestelde blad, (Tabel 1). Een zwaarder aantasting (meer dan 10 per cm² bladoppervlak) veroorzaakt een remming van de groei.Op dunne-laag chromatogrammen van gezuiverde extracten van mijten wer een indolverbinding aangetoond met een hogere Rf-waarde dan die van auxine.In bladeren van boneplanten, welke door mijten waren aangetast werd een verhoging gevonden van het gehalte aan gibberelline.     

Development of a fast analytical method for the determination of sudan dyes in chili- and curry-containing foodstuffs by high-performance liquid chromatography-photodiode array detection

A simple and fast analytical method for the determination of sudans I, II, III, and IV in chili- and curry-containing foodstuffs is described. These dyes are extracted from the samples with acetonitrile and analyzed by high-performance liquid chromatography coupled to a photodiode array detector. The chromatographic separation is carried out on a reverse phase C18 column with an isocratic mode using a mixture of acetonitrile and water. An "in-house" validation was achieved in chili- and curry-based sauces and powdered spices. Depending on the dye, limits of detection range from 0.2 to 0.5 mg/kg in sauces and from 1.5 to 2 mg/kg in spices. Limits of quantification are between 0.4 and 1 mg/kg in sauces and between 3 and 4 mg/kg in spices. Validation data show a good repeatability and within-lab reproducibility with relative standard deviations < 15%. The overall recoveries are in the range of 51-86% in sauces and in the range of 89-100% in powdered spices depending on the dye involved. Calibration curves are linear in the 0-5 mg/kg range for sauces and in the 0-20 mg/kg range for spices. The proposed method is specific and selective, allowing the analysis of over 20 samples per working day.     

Effects of ketamine on carfentanil and xylazine immobilization of white-tailed deer (Odocoileus virginianus).

Using a crossover design, the effects of the addition of ketamine to a previously determined optimal hand-injected immobilization dosage of carfentanil/xylazine were evaluated in 11 adult white-tailed deer (Odocoileus virginianus). Two i.m. ketamine dosages were evaluated: 0.15 mg/kg (low ketamine) and 0.30 mg/kg (high ketamine). Each deer was immobilized twice 2 wk apart. Inductions were video recorded and reviewed by observers, who had been blinded to drugs and dosages, who rated qualitative aspects. There were significant (P < 0.05) dosage-dependent decreases in heart rate, SaO2, and arterial pH, and a significant dosage-dependent increase in PaCO2. Induction times with both dosages were more rapid (mean 2.3 +/- 0.9 min for low ketamine and 2.3 +/- 0.6 min for high ketamine) than those reported for the same carfentanil/xylazine dosage used without ketamine. Mean quality ratings, though improved compared to those reported for carfentanil/xylazine alone, were considered "undesirable" for both dosages. Hyperthermia (temperature > 41 degrees C) was noted in 13 of 22 immobilizations. Arterial pH and PaO2 increased significantly from 10 to 20 min postrecumbency, but acidemia (pH < 7.3) was present throughout immobilization periods for all deer. There were ketamine dosage-dependent increases in respiratory components of this acidemia compared with that associated with carfentanil/xylazine alone. Possible hypoxemia was present at both sampling times for both groups, while hypercapnea (PaCO2 > 60 mm Hg) was present for the high-ketamine group only. Reversal times for naltrexone and yohimbine were rapid (mean 2.9 +/- 0.7 min for low ketamine and 3.3 +/- 0.8 min for high ketamine), with no evidence of renarcotization. Although the addition of ketamine to carfentanil/xylazine caused faster inductions and improved induction qualities, it also produced an increased incidence of hyperthermia, acidemia, hypoxemia, and hypercapnea. Supplemental oxygen and close monitoring of body temperature is recommended when using this immobilization regimen.     

A new approach to the physiological host plant-parasite relationship — A technique in the field of applied entomology

In connection with investigations on the influence of the physiological condition of the host plant on the population development of phytophagous insects and mites an apparatus for balance studies is described. Beans and radishes with their respective parasites, the two-spotted spider mite (Tetranychus urticae) and the peach aphid (Myzus persicae), were grown on an aerated small-scale waterculture. To the nutrient solution³²P was added. Mites and aphids were measurably radioactive after the experiment. Phosphorus uptake of the bean plants was much greater per gram of fresh weight than that of the radish plants. The radioactivity of animal material accounted for 2–3% of the total radioactivity recovered from nutrient solution, plants and parasites.Samenvatting In verband met het onderzoek naar de invloed van de fysiologische toestand van de waardplant op de populatieontwikkeling van fytofage insekten en mijten wordt een proefopstelling voor balansstudies beschreven (fig. 2). Bone- en radijsplanten, met hun respectievelijke parasieten het kasspint (Tetranychus urticae) en de groene perzikluis (Myzus persicae), werden gekweekt op een geaereerde kleine waterculture (fig. 3).In fig. 1 wordt schematisch weergegeven hoe, bij gebruik van twee verschillende voedingsoplossingen, de procentuele verdeling zou kunnen zijn van een bepaald element over voedingsoplossing, planten en parasieten.³²P werd aan de voedingsoplossing toegevoegd. De mijten en bladluizen, welke van de planten verwijderd werden door middel van een speciaal aangepast borstelapparaat, waren na de proef meetbaar radioactief (fig. 4).De radioactiviteit van het dierlijke materiaal bedroeg 2–3% van de totale radioactiviteit teruggevonden in voedingsoplossing, planten en parasieten.     

Dental bridging as a treatment for large oral fistulae in two horses

Chronic orocutaneous, oronasal, or orosinus fistulae can be challenging to repair. This report describes placement of a dental bridge as a treatment for oral fistulae and outcome in two horses. A 12-year-old, Westphalian gelding was presented for nasal discharge because of an oromaxillary fistula after dental repulsion of the Triadan 209 4 years earlier. The second case, a 5-year-old Oldenburg mare was presented for an orocutaneous fistula 7 weeks after dental repulsion of the Triadan 208. Both were treated by placing an 8-shaped cerclage wire, inserted through the rostral and caudal interdental spaces and crossing at the level of the missing tooth. Polymethylmethacrylate (PMMA) was then used to seal the fistula. No significant complications occurred during or after the surgery. In both cases clinical signs did not recur. In the first case the dental bridge is currently (5 years after the intervention) in place. In Case 2 the construction was removed after 1.5 years and the fistula had healed completely. This case report suggests that placing a dental bridge composed of cerclage wire and PMMA should be considered as an easy, noninvasive and efficient way to manage large oromaxillary or orocutaneous fistulae.     

Thyroid cystadenoma, colloid goiter, and hypothyroidism in an American black bear (Ursus americanus).

A 178-kg, 14-yr-old captive female American black bear (Ursus americanus) was examined because of lethargy, inappetance, obesity, and alopecia. Serum chemistry and complete blood count values were within normal limits. Based on serum levels for total thyroxine (T4), free T4 by equilibrium dialysis (fT4ED), and canine thyroid-stimulating hormone concentrations, using assays validated for domestic dogs, hypothyroidism was diagnosed presumptively, and therapy with levothyroxine sodium (0.022 mg/kg p.o. b.i.d.) was initiated. Haircoat, body weight, appetite, and activity level improved within 30 days. The levothyroxine dose was decreased twice (to 0.018 mg/kg p.o. b.i.d. and then to 0.011 mg/kg p.o. b.i.d.) during the course of treatment based on monitoring of serum T4 and fT4ED concentrations. After euthanasia for severe refractory lameness, postmortem examination revealed bilateral thyroid lobe enlargement and a fluid-filled cyst within the right lobe. Histologically, colloid goiter was present in both lobes, and a follicular cystadenoma had replaced one third of the cranial pole of the right lobe. The goiter and cystadenoma likely contributed to the hypothyroid condition in this bear and fT4ED was a more sensitive indicator of hypothyroidism than was T4. The recommended canine dosage of levothyroxine may be too high for the treatment of hypothyroidism in American black bears; 0.011 mg/kg p.o. b.i.d. may be a more appropriate dosage.     

Medium‐chain glycerides affect gut morphology,immune‐ and goblet cells in post‐weaning piglets: In vitro fatty acid screening with Escherichia coli and in vivo consolidation with LPS challenge

The influence of medium‐chain glycerides on performance and gastrointestinal well‐being in weaning piglets was assessed. First, caproic (C6), caprylic (C8) and capric (C10) acid activity against Escherichia coli was screened in vitro. Pig flora of the whole small intestine was used as inoculum. Seven in vitro incubations were done in duplicate at pH = 3 and 5: C10 (15 mM), C8 (12 mM), C6 (15, 12, 10 mM), a non‐incubated‐negative control and incubated negative control. Culture suspensions were plated on E. coli‐selective agar. Controls showed bacterial growth. C6 and C8 showed no growth at both pH‐values, where C10 showed growth at pH = 5. Secondly, an in vivo study was done with 80 weaned piglets over 42 days, housed in pens of eight animals (five pens/treatment), fed a basal diet containing broken rice/soya bean meal/fish meal and supplemented with C6 and C8 in medium‐chain glyceride form (MCT6/8, 0.175%) or antibiotic growth promoter (AGP, 0.020%) (Kasetsart University, Thailand) serving as control. Feed intake, daily gain and feed‐to‐gain ratio did not differ between MCT6/8 and AGP. Per replicate, two random selected piglets were challenged intravenously with E. coli‐lipopolysaccharide (LPS) or saline solution (S) at Days 21 and 28. All challenged animals were sacrificed; blood and digestive tract samples (jejunum/ileum) were collected at Day 35. LPS challenge consistently reduced villus height and crypt depth for MCT6/8 and AGP. However, LPS‐challenged piglets supplemented with MCT6/8 restored villus height, where AGP did not. MCT6/8 piglets had higher serum IgA, more jejunal IgA‐positive plasma cells and goblet cells than AGP. At the ileal level, results were similar, though less pronounced. The present study offers new insight in the benefits of MCT6/8 over AGP in the post‐weaning period. There is in vitro anti‐microbial action of C6 and C8 on E. coli. In vivo, MCT6/8 also has protective effects in the small intestine that may result in growth promotion.