Efficacy of copper alternatives applied as stop-sprays against Plasmopara viticola in grapevine

Journal of Plant Diseases and Protection - The six products, Armicarb, Vitisan, lime sulphur, Caso, Calce Fiocco and Ulmasud, were tested for their ability to control downy mildew (Plasmopara...     

Slit-shaped gaps are a successful silvicultural technique to promote Picea abies regeneration in mountain forests of the Swiss Alps

Many mountain forests in the Swiss Alps are dense and overmature. The resulting lack of tree regeneration threatens their future ability to provide products and services for humans, e.g., protecting settlements and infrastructure against avalanches. To promote natural regeneration, slit-shaped gaps have been cut since the 1980s in many of Switzerland's Alpine forests dominated by Norway spruce (Picea abies). However, little is known about the success of this silvicultural technique. We sampled 38 gaps in 2001 and 2006 and analysed the density and vitality of P. abies seedlings in these gaps, and monitored the growth and survival of selected seedlings between the two inventories. The gaps analysed were located in upper montane and subalpine P. abies dominated forests in the Vorderrhein valley in the Grisons. The density and vitality of large (10–129 cm tall) and small (<10 cm tall) P. abies seedlings were assessed in three parallel transects running perpendicular to the longitudinal axis of each gap. The mean density of large seedlings increased significantly between 2001 and 2006 from 0.1 to 0.3 seedlings/m², whereas that of small seedlings stayed constant at 0.7 seedlings/m², even though it shifted locally between inventories. Significantly higher regeneration densities were found for gaps with NE–SW orientation (afternoon sun) and for those located at lower altitudes. While in gaps on North-facing slopes large P. abies seedlings were more frequent on the middle transect, in gaps on South-facing slopes they were denser near the lower gap edge which is usually less exposed to direct radiation. As expected regeneration density was significantly higher within the gaps than just outside underneath the adjacent stands for all P. abies seedlings. Damage caused by browsing did not turn out to be problematic in this study site. From the selected 280 small seedlings monitored in 2001, 53% died until 2006, 33% became large seedlings and 14% remained small (<10 cm). Our results suggest that creating slit-shaped gaps is a successful procedure to promote P. abies regeneration in the upper montane and subalpine belt of the northern intermediate Alps and helps to preserve protection forests and their goods and services for the coming generations.     

Comparison of racemic ketamine and S-ketamine as agents for the induction of anaesthesia in goats

ObjectiveTo compare racemic ketamine and S-ketamine as induction agents prior to isoflurane anaesthesia.Study designProspective, blinded, randomized experimental study.AnimalsThirty-one healthy adult goats weighing 39-86 kg.MethodsGoats were premedicated with xylazine (0.1 mg kg^?1) intravenously (IV) given over 5 minutes. Each goat was assigned randomly to one of two treatments for IV anaesthetic induction: group RK (15 goats) racemic ketamine (3 mg kg^?1) and group SK (16 goats) S-ketamine (1.5 mg kg^?1). Time from end-injection to recumbency was measured and quality of anaesthetic induction and condition for endotracheal intubation were scored. Anaesthesia was maintained with isoflurane in oxygen for 90 minutes. Heart rate, invasive arterial blood pressure, oxygen saturation, temperature, end-tidal carbon dioxide and isoflurane were recorded every 5 minutes. Arterial blood samples were taken for analysis every 30 minutes. Recovery time to recurrence of swallowing reflex, to first head movement and to standing were recorded and recovery quality was scored. Two-way repeated measures anova, Mann-Whitney and a Mantel-Cox tests were used for statistical analysis as relevant with a significance level set at p < 0.05.ResultsInduction of anaesthesia was smooth and uneventful in all goats. There was no statistical difference between groups in any measured parameter. Side effects following anaesthetic induction included slight head or limb twitching, moving forward and backward, salivation and nystagmus but were minimal. Endotracheal intubation was achieved in all goats at first or second attempt. Recovery was uneventful on all occasions. All goats were quiet and needed only one or two attempts to stand.Conclusions and clinical relevanceS-ketamine at half the dose rate of racemic ketamine in goats sedated with xylazine and thereafter anaesthetised with isoflurane induces the same clinically measurable effects.     

Comparison of methods to quantify loss of hydraulic conductivity in Norway spruce

? Percent loss of hydraulic conductivity (PLC) is an important measure in plant water relations, but the available methods differ and results have rarely been compared.

? We compared PLC measured in Norway spruce (Picea abies) by quantifying conductivity before and after removing emboli, either by flushing with high water pressure or by infiltration under a partial vacuum, with relative water loss and staining conductive xylem to test advantages and possible problems of commonly applied methods.

? Infiltration removed nearly all gas from sections of drought-stressed and unstressed twigs, and flushing and infiltration efficiently removed emboli. Infiltration appears less prone to producing clogged xylem elements than high pressure flushing. Relative water loss (RWL) and the proportion of xylem stained with phloxine B (PSX) was also highly correlated with PLC, the latter can be quantified by image analysis, and also shows the pattern of xylem dysfunction. Loss of conductivity was more common in the inner annual rings, in early wood within an annual ring, and in compression wood, though pattern differed substantially between branches.

? Advantages and potential problems of these methods are discussed and it is suggested that RWL or PSX may be used as proxy measures for PLC in species when the correlations have been established.

     

Concentrations of minerals in the canine prostatic fluid

Current knowledge about the composition of the prostate fluid in healthy male dogs is limited and restricted to small case numbers. Furthermore, published data often vary significantly regarding sample processing and analytical methods. Therefore, we aimed to provide data on the composition of electrolytes and minerals in the canine prostatic fluid in a larger population (n = 30 dogs/samples) and to compare these results with the existing literature. Concentrations of sodium, potassium and copper analysed in our population were most consistent with those in the literature. Different to this, concentrations of total calcium, magnesium, zinc and inorganic phosphate varied. Whereas magnesium, zinc and inorganic phosphate seemed to depend on the analysis method, total calcium concentrations differed if centrifugation was performed or not. Our results clearly indicate a need for standardization of methods for analysis of seminal plasma components.     

Sap flux – a real time assessment of health status in Norway spruce

Top dieback of Norway spruce (Picea abies), triggered by drought in 2004–2006, has been observed in Southeast Norway and trees died within four years after appearance of the first symptoms. The aim of our study was to use sap flux measurements as a diagnostic method for assessment of tree vitality. We used the heat field deformation method to monitor the sap flux density (SFD) in four pairs of healthy and declining trees in situ. To provide retrospective information on hydraulic performance of the trees we took samples for wood anatomical analysis. After felling the trees we used the modified differential translucence method (MDT) as a proxy for the SFD measurements. Healthy trees had three times higher SFD values as declining trees. In some healthy trees we detected decreasing SFD with time. The MDT method agreed with the SFD measurements. In conclusion, we detected sap flux dysfunction in declining trees and showed that the SFD reduction may occur during a short period, prior to occurrence of any visual symptoms. We suggest incorporating the SFD measurements into the repertoire of diagnostic tools in forest pathology.     

Extending top-down mass spectrometry to proteins with masses greater than 200 kilodaltons

For characterization of sequence and posttranslational modifications, molecular and fragment ion mass data from ionizing and dissociating a protein in the mass spectrometer are far more specific than are masses of peptides from the protein's digestion. We extend the approximately 500-residue, approximately 50-kilodalton (kD) dissociation limitation of this top-down methodology by using electrospray additives, heated vaporization, and separate noncovalent and covalent bond dissociation. This process can cleave 287 interresidue bonds in the termini of a 1314-residue (144-kD) protein, specify previously unidentified disulfide bonds between 8 of 27 cysteines in a 1714-residue (200-kD) protein, and correct sequence predictions in two proteins, one with 2153 residues (229 kD).