The impact of the Department of Phytopathology at the Wageningen Agricultural University, as evaluated by citation analysis

The results of a citation analysis of all publications by the Department of Phytopathology which appeared in the period 1969–1987, but based on citations recorded by the Science Citation Index only, are presented. Together with the results of an analysis of self-citations by the eight most cited authors they suggest, that phytopathology as a science is poorly covered by the Science Citation Index.Een citatie-analyse van alle in de periode 1969–1987 verschenen publikaties van de Vakgroep Fytopathologie omvatte uitsluitend citaties voorzover vermeld in de Science Citation Index (SCI).Enkele vermeldenswaardige resultaten betreffen de krommen, die de cumulatieve citatie-aantallen weergeven (Figuren 1b en 2b) en de grafiek, die de relatieve bijdrage van uiteenlopende publikaties aan het totaal der citaties uitbeeldt (Fig. 3). Uit Fig. 2b blijkt, dat het citatieverloop van een gemiddelde publikatie het karakter van een logistische groeikromme vertoont: na een lagfase en een fase van exponentiële groei vlakt de kromme at naar een stationaire fase. Uit Fig. 3 kan worden afgeleid, dat weinig artikelen veel, en vele weinig tot het totale aantal citaties bijdragen; zo nemen 25 van de in totaal 321 geciteerde artikelen 50% van het totale aantal (3659) citaties voor hun rekening!     

Serum and Plasma Vascular Endothelial Growth Factor Levels in Various Cat Populations

Introduction:  Vascular endothelial growth factor (VEGF) is one of the most important mediators of angiogenesis. Elevated levels within tumors, and in serum, plasma, and tumor effusion have been correlated with the development of metastatic disease, recurrence, and poor prognosis in many tumors in humans. Canine VEGF has been sequenced as homologous with the human form, and elevated serum and plasma VEGF have been found in dogs with hemangiosarcoma. Feline VEGF has also been sequenced, and shares homology with the human and canine forms.
Materials and Methods:  Stored serum and plasma samples from normal cats, cats with various neoplasms, and cats with non‐neoplastic disease were evaluated with a commercial ELISA kit (R&D Systems, Minneapolis MN). Samples were run in duplicate, and a standard curve was performed for each plate. The data were analyzed for differences between populations, and between serum and plasma levels in the same patient to determine the optimal sample for evaluating VEGF in cats.
Results:  In seven apparently healthy cats mean plasma VEGF was 95.6 pg/mL. In non‐neoplastic disease (7 cases), mean plasma VEGF was 117.3 pg/mL and mean serum VEGF level was 219.7 pg/mL. In ten tumor‐bearing patients mean plasma VEGF was 247.1 pg/mL, and mean serum VEGF was 322.3 pg/mL. Statistical analysis showed no significant difference between mean serum and plasma VEGF concentrations within each group or between groups (p > 0.05).
Discussion:  Serum and plasma VEGF levels could not be used to distinguish between healthy cats and cats with neoplastic or non‐neoplastic disease.     

Spontaneous neoplasms of lagomorphs.

Many of the same neoplastic processes reported in companion animal medicine have been documented in lagomorphs. With only a few reports in the literature regarding rabbits and hares, the behavior of many of these tumors cannot be predicted. Further, based on limited current knowledge, the practitioner is left to make decisions for diagnostics and therapeutics in these cases based upon current recommendations for companion animals with adjustments for lagomorph physiology. We hope that this review of lagomorph neoplasia will inform the general practitioner of the occurrence of these tumors, promote further documentation and research of these processes in rabbits, and encourage the practitioner of rabbit medicine along with rabbit owners to consult with veterinary oncologists regarding neoplastic processes in rabbits rather than just giving a guarded prognosis.     

Effects of oral supplementation of probiotic strains of Lactobacillus rhamnosus and Enterococcus faecium on diarrhoea events of foals in their first weeks of life

Foal first diarrhoea is one of the most prominent problems in the early life of horses. Probiotics might have the potency to prevent or at least diminish neonatal diarrhoea. We hypothesised that the treatment of foals with probiotic strains of Lactobacillus rhamnosus and Enterococcus faecium starting early after birth and then daily over 2 weeks would prevent or mitigate foal heat diarrhoea. The influence of this probiotic treatment on diarrhoea incidence and growth and health performance of young foals was investigated. Thirty‐four foals were randomly allocated to two groups. From day 1 to 14 of life, the foals received either placebo (PG, n = 16) or the probiotic treatment (TG, n = 18). Clinical examination was performed, and the faeces consistency score (FCS, 1–5; with diarrhoea defined by ≤3) was recorded once per day in weeks 1 and 2 and once weekly in weeks 3–8 of life (WL). The body height was measured at birth and after two and eight WL. Diarrhoea occurred in the 1st WL in 19% and 61% of PG and TG foals respectively. In the 1st WL, diarrhoea lasted 0.3 ± 0.8 and 1.6 ± 1.4 days in PG and TG foals respectively. In the 2nd WL, diarrhoea occurred in 94% and 84% of PG and TG foals, respectively, and lasted for 3.0 ± 1.5 and 3.7 ± 1.6 days respectively. At least two periods of diarrhoea developed in 33% and 65% of PG and TG foals respectively. The TG foals grew slightly slower than the PG foals. The results indicated that the probiotic treatment of neonatal foals as performed in this study was not suitable to reduce diarrhoea within the first two WL, because contrary to the hypothesis, the TG foals suffered more frequently and for longer periods from diarrhoea than the PG foals.     

UV‐light and dietary vitamin D and their effects on ionized calcium and 25‐OH‐D plasma concentrations in captive gentoo penguins (Pygoscelis papua)

In this study, the effect of ultraviolet (UV) light and dietary vitamin D on calcium metabolism in permanently indoor‐housed gentoo penguins (Pygoscelis papua ) was investigated. The study consisted of three periods, each completed with blood samples to analyse plasma concentrations of 25‐OH‐D, 1,25‐(OH)₂‐D, ionized (iCa) and total calcium (tCa). During the first study period (D), animals were housed under routine conditions without UV‐light and fed a diet of different fish species, supplemented with 1,000 IU vitamin D per animal and day. The following study period (Baseline) of 28‐day duration consisted of the same diet without any vitamin D supplementation and without UV‐light. During the study period (UVB) artificial UV‐light was added for 3 weeks. The vitamin D content of fish was measured by high‐performance liquid chromatography. It varied between fish species and between facilities, ranging from no measurable content in capelin (Mallotus villosus ) to 7,340 IU vitamin D/kg original matter (OM) in herring (Clupea spp). The average dietary vitamin D content was 311 IU/kg OM at facility 1 and 6,325 IU/kg OM at facility 2, resulting in a vitamin D intake per animal and day without supplementation of 130 IU (25.5 IU/kg body weight BW) and 2,454 IU (438.2 IU/kg BW) respectively. The supplementation of vitamin D elevated significantly the plasma concentrations of 25‐OH‐D by an intraindividual difference of 15 (range ?2 to 59) nmol/L and tCa by 0.1 (0.0–0.3) mmol/L only at facility 2. The exposure to UV‐light raised the blood concentrations of tCa at facility 2 by 0.15 (0.1–0.2) mmol/L, and of iCa and tCa for females at facility 1 by 0.23 (0.13–0.41) mmol/L and 1.8 (1.1–2.5) mmol/L respectively. No significant influence of the study periods (D) and (UVB) was found for the concentrations of 1,25‐(OH)₂‐D at both facilities.     

Food intake and energy expenditure in growing cats with and without a predisposition to overweight

Overweight and obesity are multifactorial diseases caused by an imbalance in energy metabolism. An underlying genetic predisposition is often a factor in these conditions. In the cat breeding family of the Institute of Animal Nutrition at the Vetsuisse Faculty, University of Zurich, a segregating overweight phenotype with a genetic contribution was observed. From this breeding family, 26 kittens were followed from birth up to 8 months of age. During this time, food intake was measured using an automatic feeding station, and energy expenditure was investigated using indirect calorimetry at the ages of 4 and 6 months. Dual‐energy X‐ray absorptiometry (DEXA) was performed and blood glucose, leptin and insulin were measured at the ages of 4, 6 and 8 months. The kittens were also weighed daily for the first 2 weeks of life, every second day until weaning and once per week until 8 months of age. The body condition score (BCS) was evaluated monthly between 2 and 8 months of age. The main finding of this study is that a predisposition to overweight is connected to a higher food intake early in life, with no significant alterations in energy expenditure. The leptin blood levels were related to body fat percentage, and insulin sensitivity did not seem to be affected.     

Determining transpiration from meteorological data and crop characteristics for irrigation management

Summary Traditional meteorological estimates of evapotranspiration include empirical crop factors which are inadequate for scheduling high frequency irrigation. The performance of a transpiration model was tested and adapted to suit the operational requirements of automated irrigation systems. Hourly measurements of global solar radiation, air temperature, humidity and wind speed, obtained from an automatic weather station are inputs to the model. Additional inputs include daily updated data of plant height and leaf area index. This information is processed to determine the active coupling surface between the crop and the atmosphere. The model takes into account the resistance of the leaf to diffusion of water vapor.Calculated transpiration, based on the model, matched very closely measurements of latent heat flux in an irrigated cotton field. It was also in good agreement with water uptake measured in stems of the cotton plants using a heat pulse technique. The test also showed that implementation of the model in the field under study would have improved the efficiency of water application.Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, No. 1855-E, 1986 series