Mechanische Fruchtbehangsregulierung

The objective of the present study was to thin apple flowers without use of chemicals, in order to improve fruit quality, reduce labour for hand thinning and overcome alternate bearing. The newly developed device comprises three rotors with adjustable angles and vertically rotating ropes, which remove excess apple flowers. Eleven year-old cv. ‘Braeburn’ apple trees were thinned at flower opening (BBCH growth stage 61) with the new device in Klein-Altendorf near Bonn, Germany. Adjacent untreated, hand-thinned or chemically (benzyladenine-)thinned apple trees of the same rows served as controls. Tree branches remained un-damaged by the vertically rotating ropes. Slight leaf damages of less than 8% were observed at the fastest rotor speed of 320?rpm, which also gave the best thinning results. The portion of class one fruits >?70?mm was increased by 10% without yield loss and by up to 20% with yield losses of ca. 5–10%, depending on the settings, relative to the untreated control. This was equivalent to fruit mass gains of 10?g without yield loss and of 20?g with 10%–20% yield loss with economic gain in both cases. The single or double-sided mechanical thinning required 1.2?h ha^?1 or 2.4?h ha^?1 at a tractor speed of 2.5?km h^?1 and reduced the subsequent hand thinning by respectively 20% or 45% (by 7?h or by 15?h/ha or its cost by 50–135 €/ha). The new device gently removed up to one third of both peripheral and central flowers at a cost of less than 100 €/ha and with a negligible risk of over-thinning and without effect on return bloom.     

Maternal-fetal interaction and immunological memory

Female rats of the poorly responding, inbred F344 strain were immunized with poly(Glu(52)Lys(33)Tyr(15)) aggregated with methylated bovine serum albumin, and then they were mated. The first and second litters in the F(1) generation and in the F(2) generation showed an enhanced immune response. When poly-lysine was used as the aggregating agent, enhancement occurred in only the first litter of the F(1) generation and in the F(2) generation. In both cases, antigen was transmitted from the immunized female to her offspring, where it localized in the bone marrow and, in a few cases, in the thymus and spleen also. The transplacental passage of antigen is probably the basis for the enhanced antibody response, which is a manifestation of immunological memory.     

High-Power Infrared (8-Micrometer Wavelength) Superlattice Lasers

A quantum-cascade long-wavelength infrared laser based on superlattice active regions has been demonstrated. In this source, electrons injected by tunneling emit photons corresponding to the energy gap (minigap) between two superlattice conduction bands (minibands). A distinctive design feature is the high oscillator strength of the optical transition. Pulsed operation at a wavelength of about 8 micrometers with peak powers ranging from approximately 0.80 watt at 80 kelvin to 0.2 watt at 200 kelvin has been demonstrated in a superlattice with 1-nanometer-thick AlInAs barriers and 4.3-nanometer-thick GaInAs quantum wells grown by molecular beam epitaxy. These results demonstrate the potential of strongly coupled superlattices as infrared laser materials for high-power sources in which the wavelength can be tailored by design.     

Maillard reaction products inhibit oxidation of human low-density lipoproteins in vitro

Dietary intake of antioxidants has been associated with a reduced risk of cardiovascular diseases, which is very likely caused by their capability of prevent oxidation of low-density lipoproteins (LDL). During food processing and storage, substances with antioxidative properties are formed by Maillard reactions. In this study, the activity of Maillard products to inhibit copper-induced oxidation of human LDL in vitro was investigated. d-Glucose was heated with an equimolar amount of glycine, l-lysine, or l-arginine, for 1 h under reflux. The increase of the antioxidative activity (AOA) of the Maillard mixtures was highly significant compared to the control mixtures. Additionally, two defined Maillard products with amino reductone structure were tested. 3-Hydroxy-4-(morpholino)-3-buten-2-one (1) and amino hexose reductone (2) showed a significant and dose dependent AOA. Compound 1 was about half as active as ascorbic acid, which served as positive control. Thus, it can be concluded that Maillard products, particularly those with amino reductone structure, have the strong potential to inhibit LDL oxidation.     

Last occurrence and survival during winter of the arbovirus vector Culicoides brevitarsis at the southern limits of its distribution

SUMMARY: Linear regression analysis was used to describe the decline in numbers of Culicoides brevitarsis Kieffer into winter with monthly maximum, average and minimum temperatures at the southern limits to its distribution in New South Wales. From this, low temperature thresholds were derived when C brevitarsis would be absent from the field. The low minimum threshold ± 2 SE (95% Confidence Interval) of 8.1 ± 0.3°C was used with historical temperature data to estimate the last month that the species should occur (March to June) and the mean number of months (2 to 6.5) below the threshold at 17 selected sites. Probability for survival during winter at these sites was estimated from years when the number of consecutive months below the threshold was ≤ 2 months. This varied from zero to 51% depending on the location of the site. Last occurrence was 0.7 months later on average and absolute probabilities for survival ranged from zero to 100% when the temperatures were increased by an arbitrary 2°C.