Respiration rates and sugar accumulation in normal and moisture stressed Russet Burbank potatoes

Studies were made on Russet Burbank tubers grown under normal and moisture stressed conditions. Stressing the tubers caused increased reducing sugar accumulation in the basal end during storage. Respiration rates of apical and basal portions of stressed and normal tubers were followed during the growing season and in storage. Although its sugar content was greater, the basal end of stressed tubers respired at a significally slower rate than apical ends from the same tubers. Normal basal and apical portions showed no statistical differences in respiration although the apical end respired at a slightly faster rate than the basal end. A positive linear correlation between sugar concentration and respiration rate of the apical portion was obtained. Differences were found in the abilities of apical and basal ends to alter respiration rates in response to changes in sugar concentration. The resprationof the apical end was the more sensitive to increased sugar concentration. The basal end of stressed tubers lost some of its ability to respond, probably because of increased physiological aging caused by the stress conditions.     

Dual positional and stereospecificity of lipoxygenase isoenzymes from germinating barley (green malt): biotransformation of free and esterified linoleic acid

The lipoxygenase isoenzymes LOX1 and LOX2 from green malt were separated by isoelectric focusing, and their catalytic properties regarding complex lipids as substrates were characterized. The regio- and stereoisomers of hydroperoxy octadecadienoates (HPODE) resulting from LOX1 and LOX2 enzymatic transformations of linoleic acid, methyl linoleate, linoleic acid glycerol esters monolinolein, dilinolein, and trilinolein, and 1-palmitoyl-2-linoleoyl-glycero-3-phosphocholine (PamLinGroPCho) were determined. In addition, biotransformations of polar and nonpolar lipids extracted from malt were performed with LOX1 and LOX2. The results show that LOX2 catalyzes the oxidation of esterified fatty acids at a higher rate and is more regioselective than LOX1. The dual position specificity of LOX2 (9-HPODE:13-HPODE) with trilinolein as the substrate (6:94) was higher than the resultant ratio (13:87) when free linoleic acid was transformed. A high (S)-enantiomeric excess of 13-HPODE was analyzed with all esterified substrates confirming the formation of 13-HPODE through the LOX2 enzyme; however, 9-HPODE detected after LOX2 biotransformations showed (R)-enantiomeric excesses. PamLinGroPCho was oxygenated by LOX1 with the highest regio- and stereoselectivities among the applied substrates.     

Inter-annual variation in prevalence and intensity of mite parasitism relates to appearance and expression of damselfly resistance

Background  

Insects can resist parasites using the costly process of melanotic encapsulation. This form of physiological resistance has been studied under laboratory conditions, but the abiotic and biotic factors affecting resistance in natural insect populations are not well understood. Mite parasitism of damselflies was studied in a temperate damselfly population over seven seasons to determine if melanotic encapsulation of mite feeding tubes was related to degree of parasitism, host sex, host size, emergence timing, duration of the emergence period, and average daily air temperature.     

Structure and functioning of earthworm communities in woodland flooding systems used for drinking water production

Earthworms are known to influence water infiltration in soils, but most of the existing knowledge relates to grasslands and arable systems; little is known on the role of earthworms for water infiltration in forests. We studied earthworm populations and water infiltration rates in woodland flooding sites used for groundwater recharge and the production of drinking water. Intensive flooding may detrimentally affect earthworm populations and simultaneously result in clogging of the topsoil, with the latter being a common problem in groundwater recharge systems. However, clogging does not occur at our study site, the “Lange Erlen” (Basel, Switzerland) and total earthworm numbers and biomass in flooded sites exceeded those of non-flooded sites (+51% and +71%, respectively). Total earthworm numbers (r = 0.85***), numbers of endogeic (r = 0.64*) and epigeic (r = 0.81**) earthworms and numbers of two species (Lumbricus rubellus, r = 0.62* and Allolobophora chlorotica, r = 0.77**) significantly correlated with water infiltration rates. The results suggest that short-term flooding (max. 10 days) interrupted by longer recovery periods favor earthworm populations which likely contribute to the long-term (ca. 100 years) sustainability of the studied forest groundwater recharge system and thereby to effective and cost efficient drinking water production.     

Biochemical analysis of uterine fluid for identification of indicators for subclinical endometritis in the water buffalo (Bubalus bubalis)

Alterations in biochemical constituents of uterine fluid have been suggested for diagnosis of subclinical uterine infection in the bovine. This study was undertaken to investigate whether uterine fluid biomolecules could act as tool for diagnosis of subclinical endometritis in the buffalo. Uterine fluid samples from normal (n = 22) and subclinical endometritis (n = 18; diagnosed based on uterine cytology)‐affected buffaloes were subjected to biochemical analysis. Among the different biochemical constituents estimated, urea, urea N, cholesterol, total bilirubin and alkaline phosphatase (ALP) concentrations were significantly (p < 0.05) higher in uterine fluid obtained from subclinical endometritis‐affected buffaloes. The extent of difference between normal and subclinical endometritis‐affected buffaloes was highest in ALP (69%) followed by cholesterol (55%), bilirubin (48%), urea (30%) and urea N (30%) concentrations. Receiver operating characteristic (ROC) analysis indicated that the likelihood ratio (LR) was 3.63 for urea, indicating that buffaloes having less than the threshold concentration (47.5 mg/dl) of urea in their uterine fluid were at 3.6 times more risk to be affected with SE. The LRs for urea N, cholesterol, ALP and bilirubin were 2.33, 2.54, 2.12 and 1.65, respectively. It was concluded that ALP, urea, urea N and cholesterol concentrations in uterine fluid may serve as an aid for diagnosing subclinical endometritis in the buffalo.     

Comparison of the cardiopulmonary effects of etomidate and thiamylal in dogs.

The cardiopulmonary effects of etomidate, a nonbarbiturate, short-acting, IV anesthetic, were compared and contrasted with those of thiamylal sodium in chronically instrumented conscious dogs. Etomidate, when administered IV at dosages of 1.5 and 3.0 mg/kg of body weight, produced anesthesia lasting from 8 +/- 5 and 21 +/- 9 minutes, respectively. Heart rate, aortic blood pressure, left ventricular peak pressure, left ventricular end diastolic pressure, left ventricular contractile force, and myocardial oxygen consumption were unchanged after administration of either dose of etomidate; however, the dosage of 1.5 mg/kg produced significant (P less than 0.05) increases in respiratory rate and decreases in tidal volume. The minute volume remained unchanged from base-line values. Significant (P less than 0.05) decreases in tidal volume, arterial pH, and partial pressure of oxygen were produced, and minute volume remained unchanged when 3.0 mg of etomidate/kg of body weight was administered. Thiamylal sodium (8.0 mg/kg of body weight; given IV) produced anesthesia lasting for 14 +/- 5 minutes. Significant increases (P less than 0.05) in heart rate, arterial blood pressure, left ventricular peak pressure, and myocardial oxygen consumption were observed after IV administration. Left ventricular contractility was significantly (P less than 0.05) decreased. Respiratory rate was not significantly (P less than 0.05) affected by thiamylal although tidal volume and minute volume were decreased. These respiratory alterations resulted in significant (P less than 0.05) increases in the arterial partial pressure of carbon dioxide and decreases in pH and the partial pressure of oxygen. On the basis of cardiopulmonary function, etomidate offered rapid, safe, short duration anesthesia superior to that of thiamylal sodium.     

Double sampling for stratification in periodic inventories—Infinite population approach

Double sampling for stratification is a sampling design that is widely used for forest and other resource inventories in forest ecosystems. It is shown that this sampling design can be adapted to repeated inventories including estimators of net change, even for non-proportional allocation of second-phase units and periodically updated stratification. The method accounts for the transition of sampling units among strata. Moreover, it may outperform classical single phase designs if sample plots are appropriately allocated to strata with respect to predefined target variables, here: volume per ha of bigger trees of the main tree species. The latter requires a clear definition of predominant aims of the inventory and an appropriate optimization method. Access to inventory data of a state forest district from two occasions allowed for an optimization of the design based on the first occasion, which proved to be still advantageous on the following occasion. Estimators are developed under the infinite population approach, which is generally deemed more appropriate for forest inventories.