A method for rapidly mass laser-marking individually coded ground beetles (Coleoptera: Carabidae) in the field

Abstract.  1. A laser-marking technique is described that may be used to rapidly mass-mark and individually code insects in the field. In this study, ground beetles were marked but the method is applicable to a wide range of organisms with a hard exoskeleton or shell.
2. In a field-scale capture–recapture study conducted in winter wheat, 8266 beetles were coded. Individuals marked in the first week of the trial and recaptured 2 months later retained their codes, which were therefore considered permanent.
3. Assemblages were dominated numerically by Pterostichus cupreus , which formed more than 98% of the total captures. Of the 8046 released P. cupreus , 2269 were recaptured. As an illustration of the use of these data, the POPAN parameterisation of the Jolly–Seber model was used to estimate a whole-field population of 17 237 individuals, equating to a density of 0.46 beetles m⁻².     

Familial lecithin:cholesterol acyltransferase deficiency. Biochemistry of the cornea

Opacification of the cornea from lipid accumulation is an early and characteristic feature of familial lecithin:cholesterol acyltransferase (LCAT) deficiency. Visual impairment in a female age 48 years led to keratoplasty and the first detailed analysis of cornea in this disorder. Multilaminar figures were present, and total lipid extracts were enriched with phospholipid and cholesterol; cholesteryl esters were reduced, and accounted for about 12% of the cholesterol. Linoleate C18:2 was the predominant residue in the cholesteryl ester fatty acid fraction, with a C18:1/18:2 ratio of 1:6.5. This ratio differs from that in normal cornea, and from that in plasma and in other tissue deposits in LCAT deficiency. Various disorders of the HDL/LCAT system in plasma can lead to corneal lipid accumulation and opacification. These disorders may share general defects of lipid clearance from the cornea, but this study of LCAT cornea indicates that the character of the accumulating lipid is significantly influenced by active local metabolism, irrespective of the defect in the HDL/LCAT system also present.     

Identification of an S-locus glycoprotein allele introgressed from B. napus ssp. rapifera to B. napus ssp. oleifera.

We have previously described a developmentally regulated mRNA in maize that accumulates in mature embryos and is involved in a variety of stress responses in the plant. The sequence of the encoded 16 kDa protein (MA16) predicts that it is an RNA-binding protein, since it possesses a ribonucleoprotein consensus sequence-type RNA-binding domain (CS-RBD). To assess the predicted RNA binding property of the protein and as a starting point to characterize its function we have used ribohomopolymer-binding assays. Here we show that the MA16-encoded protein binds preferentially to uridine- and guanosine-rich RNAs. In light of these results a likely role for this protein in RNA metabolism during late embryogenesis and in the stress response is discussed.     

Effect of exercise intensity on skeletal muscle malonyl-CoA and acetyl-CoA carboxylase

Rasmussen, B. B., and W. W. Winder. Effectof exercise intensity on skeletal muscle malonyl-CoA and acetyl-CoAcarboxylase. J. Appl. Physiol. 83(4):1104-1109, 1997.Malonyl-CoA is synthesized by acetyl-CoAcarboxylase (ACC) and is an inhibitor of fatty acid oxidation. Exerciseinduces a decline in skeletal muscle malonyl-CoA, which is accompaniedby inactivation of ACC and increased activity of AMP-activated proteinkinase (AMPK). This study was designed to determine the effect ofexercise intensity on the enzyme kinetics of ACC, malonyl-CoA levels,and AMPK activity in skeletal muscle. Male Sprague-Dawley rats werekilled (pentobarbital sodium anesthesia) at rest or after 5 min ofexercise (10, 20, 30, or 40 m/min at 5% grade). The fast-twitch redand white regions of the quadriceps muscle were excised and frozen inliquid nitrogen. A progressive decrease in red quadriceps ACC maximalvelocity (from 28.6 ± 1.5 to 14.3 ± 0.7 nmol · g¹ · min¹,P < 0.05), an increase in activationconstant for citrate, and a decrease in malonyl-CoA (from 1.9 ± 0.2 to 0.9 ± 0.1 nmol/g, P < 0.05) were seen with theincrease in exercise intensity from rest to 40 m/min. AMPK activityincreased more than twofold. White quadriceps ACC activity decreasedonly during intense exercise. We conclude that the extent of ACCinactivation during short-term exercise is dependent on exerciseintensity.

     

Muscle malonyl-CoA decreases during exercise

Malonyl-CoA, the inhibitor of carnitine acyltransferase I, is an important regulator of fatty acid oxidation and ketogenesis in the liver. Muscle carnitine acyltransferase I has previously been reported to be more sensitive to malonyl-CoA inhibition than is liver carnitine acyltransferase I. Fluctuations in malonyl-CoA concentration may therefore be important in regulating the rate of fatty acid oxidation in muscle during exercise. Male rats were anesthetized (pentobarbital via venous catheters) at rest or after 30 min of treadmill exercise (21 m/min, 15% grade). The gastrocnemius/plantaris muscles were frozen at liquid N2 temperature. Muscle malonyl-CoA decreased from 1.66 +/- 0.17 to 0.60 +/- 0.05 nmol/g during the exercise. This change was accompanied by a 31% increase in cAMP in the muscle. The decline in malonyl-CoA occurred before muscle glycogen depletion and before onset of hypoglycemia. Plasma catecholamines, corticosterone, and free fatty acids were all significantly increased during the exercise. This exercise-induced decrease in malonyl-CoA may be important for allowing the increase in muscle fatty acid oxidation during exercise.     

The role of water retaining substrata on the photosynthetic response of three drought tolerant phototrophic micro-organisms isolated from a terrestrial habitat

The water prerequisites of two drought tolerant Oscillatoria type cyanobacteria and one green alga were estimated by their ability to accomplish photosynthesis (carbon dioxide fixation) at conditions of subsaturating water supply. Fixation was zero in desiccated samples. Equilibration with solely water-saturated air did not enable any photosynthesis. However, granted properties of the physical environment of the samples could re-establish photosynthesis activity. These properties were elected by chosing membrane filters with different water retention characteristics as supporting substrata for the test samples in the de-and rehydration steps. Rehydration enabled the recovery of photosynthesis of desiccated samples only on the filters with good water retention, the filters with bad water retention were found ineffective. The Oscillatoria strains showed photosynthesis instantaneously and revealed nearly 100% viability. In contrast, rewetted cells of the green alga showed only 35% viability and the recovery of photosynthesis occurred only after 5 h. These differences reflect the natural environmental conditions: cyanobacteria are the first colonizers in the barren sand, whereas green algae can only start to colonize after progressing improvement of the water retention properties brought about by the pioneering cyanobacteria. The results will be discussed in the light of different specific mechanisms available to organisms which endeavour osmotic and matric water stress.Abbreviations DCMU 3(3,4-dichlorophenyl)-1,1-dimethyl-urea - DMF dimethylformamide - PFD photon flux density - TAPS N-tris[hydroxymethyl]methyl-3-amino-propanesulfonic acid     

Correction of light-scattering errors in spectrophotometric protein determinations

Errors due to light scattering are a feature of spectrophotometrie methods of protein determination. The experimental conditions may be chosen to allow calculation of the scatter contribution, which is obtained essentially from the linear relationship between log turbidity and log incident wavelength, together with knowledge of the slope of such functions. Using this information, the scatter corrections may be obtained by various simple and rapid methods, applicable to single or multicomponent protein solutions.