Female mate choice across mating stages and between sequential mates in flour beetles

Few studies have examined how female premating choice correlates with the outcome of copulatory and post-copulatory processes. It has been shown that polyandrous Tribolium castaneum females discriminate among males before mating based on olfactory cues, and also exert cryptic choice during mating through several mechanisms. This study tested whether a male's relative attractiveness predicted his insemination success during copulation. Bioassays with male olfactory cues were used to rank two males as more and less attractive to females; each female was then mated to either her more attractive male followed by less attractive male, or vice versa. Dissections immediately after second copulations revealed a significantly higher percent of successful inseminations for females that remated with more attractive males compared with those that remated with less attractive males. These results indicate that cryptic female choice during copulation reinforces precopulatory female choice in T. castaneum, and suggest that females could use cryptic choice to trade up to more attractive males, possibly gaining better phenotypic or genetic quality of sires.     

UV-B induced stress responses in three rice cultivars

UV-B responses of three rice (Oryza sativa L.) cultivars (Sasanishiki, Norin 1 and Surjamkhi) with different photolyase activity were investigated. Carbon dioxide assimilation data support that Sasanishiki was less sensitive to UV-B than Norin 1 and Surjamkhi. UV-B radiation sharply decreased the content of Rubisco protein in Surjamkhi and has no effect in Sasanishiki. The photochemical activities of photosystem (PS) 1 and PS 2 was slightly affected by UV-B treatment. The content of H₂O₂ and the activities of antioxidant enzymes, catalase (CAT), peroxides (POX) and superoxide dismutase (SOD) were enhanced after UV-B treatment. The activities of CAT and POX isoenzymes in Sasanishiki were more enhanced by UV-B radiation than those in Norin 1 and Surjamkhi.     

Response of Scenedesmus Incrassatulus to Salt Stress as Affected by Methyl Jasmonate

Exposure of the freshwater green alga Scenedesmus incrassatulus Bohl, strain R-83 to salt stress (175 mM NaCl) resulted in a reduction of its growth and ¹⁴CO₂ fixation and in an increase of accumulation of free proline and malondialdehyde (MDA). The accumulation of proline in the light was higher than in dark. NaCl significantly inhibited the Fe-induced release of organic chelators from the cells. Exogenously supplied 10^–4M methyl jasmonate (JA-Me) did not considerably change the ¹⁴CO₂ fixation, but increased proline and MDA accumulation in the cells and moderately inhibited the release of chelators from cells. JA-Me supplied simultaneously with NaCl helps the algae to counteract the salt stress.     

Biological activities of human interferon and 2′–5′ oligoadenylates in plants

Exogenous human interferon 2 (IFN) and 2–5 oligoadenylates (2–5A) have been shown to cause at least a dual physiological effect in tobacco and wheat: (i) increased cytokinin activity and (ii) induced synthesis of numerous proteins, among which members of two groups of stress proteins have been identified, namely pathogenesis-related (PR) and heat shock (HS) proteins. These effects were observed only by low concentrations of these substances: IFN at 0.1–1 u/ml and 2–5A at 1–10 nM.     

Magnetic resonance tomography in the diagnosis of renovascular hypertension]

MR tomography was used for investigation of 38 patients with renovascular hypertension (RVH) and 26 healthy persons. A possibility of the use and practical value of the method in the diagnosis and evaluation of renal function and renal arteries (RA) were under study. Some quantitative MRT indices were calculated both for the patients and healthy persons. They included spin-spin relaxation time, proton density, and signal intensity. These data can provide important information on renal function in RVH with relation to kidney sizes and the state of the renal parenchyma (evaluation of the cortical substance and medulla and the border between them). In some cases MRT ensures noninvasive diagnosis of PA stenosis.