Effect of salinity on water relations of wild barley plants differing in salt tolerance

Root hydraulic conductivity was decreased by salinity in barley plants in parallel with slower transpiration rates and a down-regulation of aquaporin expression in the roots. The effects were larger and faster in a more salinity-tolerant line

Effects of phosphate shortage on root growth and hormone content of barley depend on capacity of the roots to accumulate aba

Although changes in root architecture in response to the environment can optimize mineral and water nutrient uptake, mechanisms regulating these changes are not well-understood. We investigated whether P deprivation effects on root development are mediated by abscisic acid (ABA) and its interactions with other hormones. The ABA-deficient barley mutant Az34 and its wild-type (WT) were grown in P-deprived and P-replete conditions, and hormones were measured in whole roots and root tips. Although P deprivation decreased growth in shoot mass similarly in both genotypes, only the WT increased primary root length and number of lateral roots. The effect was accompanied by ABA accumulation in root tips, a response not seen in Az34. Increased ABA in P-deprived WT was accompanied by decreased concentrations of cytokinin, an inhibitor of root extension. Furthermore, P-deficiency in the WT increased auxin concentration in whole root systems in association with increased root branching. In the ABA-deficient mutant, P-starvation failed to stimulate root elongation or promote branching, and there was no decline in cytokinin and no increase in auxin. The results demonstrate ABA’s ability to mediate in root growth responses to P starvation in barley, an effect linked to its effects on cytokinin and auxin concentrations

Structure, impurity composition, and photoluminescence of mechanically polished layers of single-crystal silicon

The introduction of optically active defects (such as atomic clusters, dislocations, precipitates) into a silicon single crystal using irradiation, plastic deformation, or heat treatment has been considered a possible approach to the design of silicon-based light-emitting structures in the near infrared region. Defects were introduced into silicon plates by traditional mechanical polishing. The changes in the defect structure and the impurity composition of damaged silicon layers during thermal annealing (TA) of a crystal were examined using transmission electronic microscopy and x-ray fluorescence. Optical properties of the defects were studied at 77 K using photoluminescence (PL) in the near infrared region. It has been shown that the defects generated by mechanical polishing transform into dislocations and dislocation loops and that SiO2 precipitates also form as a result of annealing at temperatures of 850 to 1000°C. Depending on the annealing temperature, either oxide precipitates or dislocations decorated by copper atoms, which are gettered from the crystal bulk, make the predominant contribution to PL spectra. © 2005 Pleiades Publishing, Inc

Treatment of Marburg and Ebola hemorrhagic fevers: A strategy for testing new drugs and vaccines under outbreak conditions.

The filoviruses, Marburg and Ebola, have the dubious distinction of being associated with some of the highest case-fatality rates of any known infectious disease-approaching 90% in many outbreaks. In recent years, laboratory research on the filoviruses has produced treatments and vaccines that are effective in laboratory animals and that could potentially drastically reduce case-fatality rates and curtail outbreaks in humans. However, there are significant challenges in clinical testing of these products and eventual delivery to populations in need. Most cases of filovirus infection are recognized only in the setting of large outbreaks, often in the most remote and resource-poor areas of sub-Saharan Africa, with little infrastructure and few personnel experienced in clinical research. Significant political, legal, and socio-cultural barriers also exist. Here, we review the present research priorities and environment for field study of the filovirus hemorrhagic fevers and outline a strategy for future prospective clinical research on treatment and vaccine prevention

A case of cicatricial conjunctival pemphigoid

A clinical case of a rare and severe chronic autoimmune disease - pemphigoid scarring of the conjunctiva in a female patient aged 66 is presented. The etiological diagnosis was established only 14 months later, when serious complications, including a severe syndrome of dry eye, symblepharon and changes in the cornea manifested in a vascularized pannus. Ophthalmologists are recommended to be watchful of scarring pemphigoid in cases of persistent and severe bilateral conjunctivitis, torpid to conventional treatment or showing signs of cicatrical mucosa changes, especially in the lower arch, and combined with bullous-erosive lesions of mucosa especially in the oral cavity, epipharynx, or skin. Keywords: scarring pemphigoid, conjunctivitis, symblepharon, dry eye syndrome // Russian Ophthalmological Journal, 2016; 3: 81-4. doi: 10.21516/2072-0076-2016-9-3-81-84

Phytohormone Mediation of Interactions Between Plants and Non-Symbiotic Growth Promoting Bacteria Under Edaphic Stresses

The capacity of rhizoshere bacteria to influence plant hormonal status, by bacterial production or metabolism of hormones, is considered an important mechanism by which they promote plant growth, and productivity. Nevertheless, inoculating these bacteria into the plant rhizosphere may produce beneficial or detrimental results depending on bacterial effects on hormone composition and quantity in planta, and the environmental conditions under which the plants are growing. This review considers some effects of bacterial hormone production or metabolism on root growth and development and shoot physiological processes. We analyze how these changes in root and shoot growth and function help plants adapt to their growth conditions, especially as these change from optimal to stressful. Consistent effects are addressed, along with plant responses to specific environmental stresses: drought, salinity, and soil contamination (with petroleum in particular)

Water relations and growth of original barley plants and its ABA-deficient mutants at increased air temperature

Data on the effects of air temperature increase by 4A degrees C on leaf growth and water relation parameters in barley (Hordeum vulgare L.) plants in original cv. Steptoe and its ABA-deficient mutant (AZ24) are presented. An increase in temperature firstly resulted in the cessation of leaf elongation in both genotypes; however, later in cv. Steptoe plants, as distinct from mutants, the rate of leaf length increment was completely restored. Before air warming, transpiration was more intense in mutant plants; at increased temperature, transpiration was activated in both genotypes. After growth resumption, the water potential in cv. Steptoe plants somewhat increased as compared with initial level (before warming). In AZ34 leaves, in contrast, the water potential, which was initially below that in cv. Steptoe leaves, reduced after temperature increase. The calculation of total hydraulic conductivity of the plants and osmotic hydraulic conductivity in the roots showed that these parameters increased in cv. Steptoe and were not changed in AZ34 mutants. At temperature increase, the level of ABA was not changed in AZ34 mutants, whereas in Steptoe plants it increased in the roots and decreased in the shoots. It was concluded that a capability of ABA synthesis is required for the control of total hydraulic conductivity under changing environmental conditions

Structure, impurity composition, and photoluminescence of mechanically polished layers of single-crystal silicon

The introduction of optically active defects (such as atomic clusters, dislocations, precipitates) into a silicon single crystal using irradiation, plastic deformation, or heat treatment has been considered a possible approach to the design of silicon-based light-emitting structures in the near infrared region. Defects were introduced into silicon plates by traditional mechanical polishing. The changes in the defect structure and the impurity composition of damaged silicon layers during thermal annealing (TA) of a crystal were examined using transmission electronic microscopy and x-ray fluorescence. Optical properties of the defects were studied at 77 K using photoluminescence (PL) in the near infrared region. It has been shown that the defects generated by mechanical polishing transform into dislocations and dislocation loops and that SiO2 precipitates also form as a result of annealing at temperatures of 850 to 1000°C. Depending on the annealing temperature, either oxide precipitates or dislocations decorated by copper atoms, which are gettered from the crystal bulk, make the predominant contribution to PL spectra. © 2005 Pleiades Publishing, Inc

Structure, impurity composition, and photoluminescence of mechanically polished layers of single-crystal silicon

The introduction of optically active defects (such as atomic clusters, dislocations, precipitates) into a silicon single crystal using irradiation, plastic deformation, or heat treatment has been considered a possible approach to the design of silicon-based light-emitting structures in the near infrared region. Defects were introduced into silicon plates by traditional mechanical polishing. The changes in the defect structure and the impurity composition of damaged silicon layers during thermal annealing (TA) of a crystal were examined using transmission electronic microscopy and x-ray fluorescence. Optical properties of the defects were studied at 77 K using photoluminescence (PL) in the near infrared region. It has been shown that the defects generated by mechanical polishing transform into dislocations and dislocation loops and that SiO2 precipitates also form as a result of annealing at temperatures of 850 to 1000°C. Depending on the annealing temperature, either oxide precipitates or dislocations decorated by copper atoms, which are gettered from the crystal bulk, make the predominant contribution to PL spectra. © 2005 Pleiades Publishing, Inc