The diagnosis of nephrogenic diabetes insipidus in the dog]

Nephrogenic diabetes insipidus is characterized by polyuria, hyposthenuria and compensatory polydipsia. With conventional clinical and laboratory examinations the diagnosis can be established and the differential diagnostic diseases excluded. In order to verify the diagnosis, differentiate the condition from central and nephrogenic diabetes insipidus and rule out psychogenic polydipsia, additional laboratory studies are required: of these, the concentration test, modified Carter-Robbins test and AVP stimulation test are described.     

Beitr?ge zur Generationsfrage der Borkenk?fer

Ohne Zusammenfassung     

Evaluation of reticulocyte hemoglobin content (RET‐He) in the diagnosis of iron‐deficient erythropoiesis in dogs

Background

Reticulocyte hemoglobin content provided by the Siemens ADVIA (CHr) is an established marker of iron deficiency. The IDEXX ProCyte Dx hematology analyzer now provides a similar variable, reticulocyte hemoglobin equivalent (RET‐He).

Objectives

The objective was to evaluate RET‐He and its diagnostic utility in dogs, and to calculate a cutoff value for diagnosing iron‐deficient erythropoiesis (IDE). Furthermore, the prevalence of RET‐He values below this cutoff value was established.

Methods

One hundred and seventy‐one CBCs of healthy dogs were used to establish a RI. Stability of RET‐He was evaluated by repeated measurements over 48 hours (n = 10). The 25‐run coefficient of variation (CV) was calculated, and correlation and bias between measurements of RET‐He and CHr were assessed (n = 190). A cutoff value for diagnosing IDE was calculated. The utility of RET‐He in the detection of IDE was evaluated in 123 dogs. The prevalence of low RET‐He values was assessed retrospectively in a multicenter study (2012–2014) under participation of 7 veterinary clinics.

Results

Reticulocyte hemoglobin equivalent with an RI of 22.2 to 28.6 pg was statistically stable over 48 hours (P = .10). The CV was 1.8%. A fair correlation (ρ = 0.74) between RET‐He and CHr with a small bias of ?0.6 pg was found. The cutoff value for diagnosing IDE was 20.9 pg (sensitivity: 85%; specificity: 99%). The prevalence of RET‐He values below 20.9 pg was 10.3% (1084/10,553 dogs).

Conclusions

RET‐He on the ProCyte Dx is a precise screening tool in dogs to detect iron‐deficient erythropoiesis.     

Urban land use types contribute to grassland conservation: The example of Berlin

Urbanisation is an important driver of biodiversity loss, also contributing to habitat loss and fragmentation of grasslands at the urban-rural interface. While urban green spaces are known to include many grassland habitats, it is uncertain to what extent urban land use types harbour grasslands of special conservation interest and whether patch characteristics and connectivity of these differ from grasslands on agricultural land. By relating the city-wide biotope mapping to the land use mapping of Berlin, Germany, we assessed (1) to which specific urban land use types the major grassland biotope types belong, (2) differences in patch characteristics and connectivity, and (3) the conservation value of grassland patches at a typological level by means of their legal protection status. Grasslands cover 5% of Berlin's surface, and 43% of that area is assigned to legally protected grassland types. The majority of legally protected grassland (71%) lies on urban land opposed to 29% on agricultural land. Airports and historic parks, which only cover 2% of land in Berlin, contain one-third of all protected dry grasslands. Wet grassland is more confined to agricultural land. In airports and agricultural areas, grassland patches are larger but of a more complex shape than those in historic parks. In airports, grassland patches show greater connectivity as they are situated in grassland-dominated surroundings. Grassland in historic parks appears to be more vulnerable due to smaller patch sizes and higher fragmentation. The example of Berlin demonstrates that the urban green infrastructure can clearly contribute to grassland conservation and may thus partially compensate for the decline of traditional grasslands in cultural landscapes. It will be important to involve residents and landowners in urban grassland conservation and management because most grassland of special conservation interest (57%) was found outside of conservation areas.     

The effect of quality bucking and automatic bucking on harvesting productivity and product recovery in a pine-dominated stand

On-board computers (OBC) of harvesting machines can now provide optimized bucking (task of cutting stems into different log lengths) by relying on value and demand matrices. Despite existing benefits of these systems in certain countries, they remain largely underutilized and generally poorly understood in German mechanized forest operations. The study aimed to compare and quantify the differences in harvesting productivity and value recovery between two treatments: quality bucking (OFF) and automatic bucking (ON). A mature forest stand with a high proportion of Scots pine (Pinus sylvestris L.) was divided into plots (30 m × 100 m) where initial tests of both treatments were randomly distributed and replicated 10 times for a total of 11 plots per treatment. Pre-harvest inventory was performed on each tree targeted for removal via a commercial thinning silvicultural treatment. Mechanized harvesting was performed with an excavator-based Atlas Kern T23 Königstiger single-grip harvester. The same assortment specifications and prices were used for both treatments but on-board optimized bucking solutions were applied in the ON plots, whereas the operator had full control of the products to be recovered in the OFF plots. During harvesting operations, continuous time and motion was performed in all plots. Average harvesting productivity was higher—but not statistically significant—in OFF plots compared to ON plots by 2.0 and 0.46 m³/PMH₀ for pine and spruce trees, respectively. Even if there was no difference detected in volume recovery for both treatments and tree species, value recovery was more than 1.60 € per cubic meter higher for pine in larger diameter classes when using quality bucking. This may be due to the fact that the algorithm of the OBC is designed for pine trees with a simpler crown architecture than trees harvested in this study. Results supporting quality bucking over automatic bucking in a Scots pine-dominated stands provide important forest operational information to managers.

     

Short‐term response of the Ca cycle of a montane forest in Ecuador to low experimental CaCl2 additions

The tropical montane forests of the E Andean cordillera in Ecuador receive episodic Sahara‐dust inputs particularly increasing Ca deposition. We added CaCl₂ to isolate the effect of Ca deposition by Sahara dust to tropical montane forest from the simultaneously occurring pH effect. We examined components of the Ca cycle at four control plots and four plots with added Ca (2 × 5 kg ha^–1 Ca annually as CaCl₂) in a random arrangement. Between August 2007 and December 2009 (four applications of Ca), we determined Ca concentrations and fluxes in litter leachate, mineral soil solution (0.15 and 0.30 m depths), throughfall, and fine litterfall and Al concentrations and speciation in soil solutions. After 1 y of Ca addition, we assessed fine‐root biomass, leaf area, and tree growth. Only < 3% of the applied Ca leached below the acid organic layer (pH 3.5–4.8). The added CaCl₂ did not change electrical conductivity in the root zone after 2 y. In the second year of fertilization, Ca retention in the canopy of the Ca treatment tended to decrease relative to the control. After 2 y, 21% of the applied Ca was recycled to soil with throughfall and litterfall. One year after the first Ca addition, fine‐root biomass had decreased significantly. Decreasing fine‐root biomass might be attributed to a direct or an indirect beneficial effect of Ca on the soil decomposer community. Because of almost complete association of Al with dissolved organic matter and high free Ca²⁺ : Al³⁺ activity ratios in solution of all plots, Al toxicity was unlikely. We conclude that the added Ca was retained in the system and had beneficial effects on some plants.     

Structural and physiological changes associated with the skin spot disorder in apple

Skin spot is an important physiological disorder of ‘Elstar’ apples (Malus × domestica Borkh.) that occurs after fruit have been removed from controlled atmosphere storage. Skin spots are irregular patches of small, round, brown blemishes. Cross-sections reveal a browning of protoplasts (coagulated) and of cell walls that extends into the hypodermis. Skin spots are always associated with linear, gaping and non-gaping microcracks in the cuticle. Staining of apple skin with calcofluor white usually results in white fluorescence of cell walls but, within a skin spot, the white fluorescence is weak or absent. Cell walls within, and in the immediate vicinity of skin spots stain with phloroglucin/HCl indicating the presence of lignin. The area of skin affected by skin spots was positively and linearly correlated with the area of the non-blush fruit surface infiltrated by acridine orange. In general, skin spots were limited to the non-blush fruit surface and occurred more frequently near the stem-end than the calyx region of the fruit. Skin spot areas were correlated with a 2.5-fold increase in water vapour permeability compared with unaffected areas (23.8 ± 4.0 m s⁻¹ with skin spots, 9.6 ± 2.1 × 10⁻⁵ m s⁻¹ without skin spots). Strips of the fruit skin from regions with skin spots had an increased maximum force and modulus of elasticity. Dipping fruit in ascorbic acid (0.1 or 0.3 mM for 10 min) before storage decreased the area affected by skin spots. There was no effect of dipping in ethanol/water (70%, v/v, 15 min) or in solutions of captan (1.5 g L⁻¹, 10 min) or trifloxystrobin (0.1 g L⁻¹, 10 min). In contrast, prestorage treatment with 1-methylcyclopropene (630 nL L⁻¹ for 24 h) or poststorage incubation in H₂O₂ (10% for 2, 6, 10 and 16 h) increased skin spots. Our data are consistent with a typical cell response to an oxidative burst that seems to be focussed on particular regions of the ‘Elstar’ fruit surface by concentrations of cuticular microcracks, and that is possibly caused by reoxygenation injury upon removal from CA storage.