Breaking the rest of apple buds by narrow-distillation-range oil and dinitro-o-cresol

The effect of various combinations of dinitro-o-cresol (DNOC) and narrow-distillation-range mineral oil (NRO) was tested during 4 consecutive years on breaking bud-rest and on fruiting of ‘Golden Delicious’ apple trees under mild winter conditions. Breaking of lateral leaf buds was directly correlated with oil concentration between 2.4 and 8.8%, while DNOC did not increase bud break at concentrations over 0.12% in the rest-breaking spray. Lower phytotoxicity of NRO compared with winter oil allowed safe use of higher concentrations of the former.Increased lateral leaf bud-break resulted in formation of more spurs and thus increased the yield in subsequent years. These higher yields were not accompanied by reductions in mean fruit weight or in trunk diameter, suggesting an increase in overall bearing potential of the tree by the best rest-breaking treatments.     

CD44 is highly expressed on milk neutrophils in bovine mastitis and plays a role in their adhesion to matrix and mammary epithelium

Mastitis, inflammation of the mammary gland, is a common and economically important disease in dairy animals. Mammary pathogenic organisms, such as Escherichia coli, invade the teat canal,milk ducts, and mammary alveolar space, replicate in mammary secretions, and elicit a local inflammatory response characterized by massive recruitment of blood polymorphonuclear neutrophil leukocytes (PMN) into the alveoli and milk ducts. CD44 is a trans-membrane glycoprotein previously shown to play a role in mediation and control of blood PMN recruitment in response to inflammatory signals. Here we show, for the first time, increased expression of CD44 on recruited milk PMN in bovine mastitis and the expression of a CD44 variant, CD44v10, on these PMN. Furthermore, we demonstrate that CD44 mediates specific adhesion of bovine blood PMN to hyaluronic acid and mammary epithelial cells. Our results suggest that in mastitis CD44 plays a role in recruiting blood PMN into the mammary glands, the exact nature of this role needs to be elucidated.     

Field estimation of leaf nitrogen by light transmittance

A highly significant negative correlation was found between percentage transmittance of photosynthetically active radiation (%TPAR) through a varied sample of walnut leaves and their extractable chlorophyll content (expressed on a leaf‐area basis). The %TPAR was negatively correlated with leaf nitrogen (N) expressed on a leaf‐area basis. When leaves were sampled from throughout the canopy of a walnut tree, no correlation was obtained between either chlorophyll content or %TPAR and leaf N based on leaf dry wt.; this was due to variation between exposed and shaded leaves in leaf thickness and specific leaf weight (SLW). Regression analysis indicated better correlation between transmittance of photosynthetically active radiation (%TPAR) and leaf N when data were fitted to quadratic or exponential functions rather than to a linear formula. Thus, estimation of leaf N level by %TPAR is more sensitive at lower levels of leaf N. When exposed leaves from trees differing in N status were analyzed, %TPAR was negatively correlated with almond and nectarine leaf N levels. Although variation among %TPAR determinations is greater than variation among analytical N determinations, the ease and rapidity of the proposed method could provide a rapid, inexpensive estimate of leaf N in the field.     

Essential role of neutrophils but not mammary alveolar macrophages in a murine model of acute Escherichia coli mastitis

Mastitis, the inflammation of the mammary gland, is an important disease affecting dairy animals worldwide. The disease is caused by mammary pathogenic bacteria and Escherichia coli are frequently implicated. Virulence factors of mammary pathogenic E. coli are only partially known and intramammary challenge with LPS elicits neutrophil recruitment in experimental bovine and murine mastitis models. We have previously shown that neutrophil recruitment in LPS-induced murine mastitis is strictly dependent on mammary alveolar macrophages. However, the relative role of alveolar macrophages and blood neutrophils in E. coli mastitis is not well defined. To this end, we selectively depleted mammary alveolar macrophages or blood neutrophils before intramammary challenge with E. coli strain P4 (ECP4). Mice depleted of alveolar macrophages prior to intramammary challenge recruited neutrophils normally and restricted bacterial growth and interstitial invasion. Importantly however, upon depletion of alveolar macrophages, ECP4 invaded the mammary alveolar epithelial cells and formed intracellular bacterial communities. In contrast, neutrophil depletion prior to intramammary infection with ECP4 was associated with unrestricted bacterial growth, tissue damage, severe sepsis and mortality. This study suggests that neutrophils but not alveolar macrophages provide essential antimicrobial defense against mammary pathogenic E. coli. Furthermore, we show here similar invasion after depletion of alveolar macrophages as in our previous studies showing that LPS/TLR4 signaling on alveolar macrophages abrogates ECP4 invasion of the mammary epithelium. Interestingly, similar ECP4 invasion and formation of intracellular communities were also observed following intramammary infection of either iNOS gene-deficient or IL-1 receptor type 1 gene-deficient mice.     

Rooting of peach hardwood cuttings for the meadow orchard

In order to make peach meadow orchard systems feasible, the possibility of propagating peaches by hardwood cuttings and thus reducing the establishment cost of this extremely high-density planting system was examined.A medium temperature of 25°C was harmful to auxin-treated peach cuttings, but excellent rooting could be obtained at a temperature as low as 12°C. Further trials conducted under outdoor conditions in winter in the coastal plain of Israel, with a soil temperature of 12–14°C, did not show any effect of timing on rooting, providing the cutting was taken mature enough (after mid-November) and not later than about 6 weeks prior to bud break. In 30 days root initiation started. Although variations were found between cultivars, 1500 mg/l of indole butyric acid in a 5-second base-dip was found to act well with most cultivars. Good aeration was shown to be critical for good root formation. Leaving the cutting for 1 month in damp sand prior to planting in orchard soil was satisfactory. An area of a few hectares of commercial meadow orchards has already been established with this method.     

Sequence-specific molecular lithography on single DNA molecules

Recent advances in the realization of individual molecular-scale electronic devices emphasize the need for novel tools and concepts capable of assembling such devices into large-scale functional circuits. We demonstrated sequence-specific molecular lithography on substrate DNA molecules by harnessing homologous recombination by RecA protein. In a sequence-specific manner, we patterned the coating of DNA with metal, localized labeled molecular objects and grew metal islands on specific sites along the DNA substrate, and generated molecularly accurate stable DNA junctions for patterning the DNA substrate connectivity. In our molecular lithography, the information encoded in the DNA molecules replaces the masks used in conventional microelectronics, and the RecA protein serves as the resist. The molecular lithography works with high resolution over a broad range of length scales from nanometers to many micrometers.     

DNA-templated carbon nanotube field-effect transistor

The combination of their electronic properties and dimensions makes carbon nanotubes ideal building blocks for molecular electronics. However, the advancement of carbon nanotube-based electronics requires assembly strategies that allow their precise localization and interconnection. Using a scheme based on recognition between molecular building blocks, we report the realization of a self-assembled carbon nanotube field-effect transistor operating at room temperature. A DNA scaffold molecule provides the address for precise localization of a semiconducting single-wall carbon nanotube as well as the template for the extended metallic wires contacting it.     

Influence of three contrasted climatic conditions on endodormant vegetative and floral peach buds: analyses of their intrinsic growth capacity and their potential sink strength compared with adjacent tissues

Three treatments with various temperature-photoperiod combinations (LDW: long-day warm; SDW: short-day warm; SDC: short-day cold) were applied to endodormant vegetative and floral peach buds. In order to analyze the effect of these factors on their dormancy state, the following complementary methods were used: (1) for vegetative buds, the ‘single-node cutting' test that measures the growth capacity of the buds connected to the shoot and integrates endo- and short-distance paradormancy; (2) for floral buds, growth rate of the primordia that integrates endo- and all paradormancy. For both kinds of buds: (3) the ‘nucleotides' test that reveals the intrinsic growth capacity of the isolated bud, i.e. endodormancy, by measuring the potential of converting adenosine to non-adenylic nucleotides; (4) the intracellular pH measurement of primordia and adjacent tissues (cushion and shoot) which is supposed to reflect their relative sink strength for nutrients and the competition between them. This is a possible element of short-distance paradormancy.

Temperature, and not photoperiod, strongly determined the evolution of dormancy in vegetative and floral buds. Exposure to temperatures >20°C, prevented the buds recovering any intrinsic growth capacity, but they did it with notable rapidity under 10–18°C temperature regime (SDC). After one month, under all treatments, consistent with the poor chilling effect (nil under LDW and SDW, one third of the normal requirement of chilling units computed with the ‘dynamic' model under SDC), a residual inhibition of the vegetative bud growth was shown to exist at the cutting level. It must be hypothesized as strong short-distance paradormancy. In the floral buds, growth of the primordia started shortly after exposure to SDC conditions. This is possible provided it is assumed that only very weak residual short-distance paradormancy, if any, remained. Intracellular pH values of the studied tissues were influenced by temperature and photoperiod, but the corresponding gradients of the potential sink strength did not fit well with the paradormancy patterns that had been assumed for the vegetative and floral buds, especially under SDC treatment.