Effect of bovine adenovirus 3 on mitochondria

Viruses alter the structure and the function of mitochondria for survival. Electron microscopy analysis of the cells infected with bovine adenovirus 3 revealed extensive damage to the inner mitochondrial membrane characterized by dissolution of the cristae and amorphous appearance of mitochondrial matrix with little or no damage to the outer mitochondrial membrane. There were fewer cristae with altered morphology. Potential patches of protein synthesis machinary around mitochondria could be observed at 12 hours post infection (hpi). At 24 hpi, the multi vascular bodies were evident throughout the infected cell. ATP production, mitochondrial Ca²⁺ and mitochondrial membrane potential (MMP) peaked at 18 hpi but decreased significantly at 24 hpi. This decrease coincided with the increased production of superoxide (SO) and reactive oxygen species (ROS), at 24 hpi indicating acute oxidative stress in the cells and suggesting a complete failure of the cellular homeostatic machinary. The results reveal an intericate relationship between Ca²⁺ homeostasis, the ATP generation ability of cells, SO and ROS production, and regulation of MMP following infection by bovine adenovirus 3.     

Ultrasonographic Characterization of Follicle Deviation in Follicular Waves with Single Dominant and Codominant Follicles in Dromedary Camels (Camelus dromedarius)

Follicular wave emergence was synchronized by treating camels with GnRH when a dominant follicle (DF) was present in the ovaries. Animals were scanned twice a day from day 0 (day of GnRH treatment) to day 10, to characterize emergence and deviation of follicles during the development of the follicular wave. Follicle deviation in individual animals was determined by graphical method. Single DFs were found in 16, double DFs in 9 and triple DFs in two camels. The incidence of codominant (double and triple DFs) follicles was 41%. The interval from GnRH treatment to wave emergence, wave emergence to deviation, diameter and growth rate of F1 follicle before or after deviation did not differ between the animals with single and double DFs. The size difference between future DF(s) and the largest subordinate follicle (SF) was apparent from the day of wave emergence in single and double DFs. Overall, interval from GnRH treatment to wave emergence and wave emergence to the beginning of follicle deviation was 70.6 ± 1.4 and 58.6 ± 2.7 h, respectively. Mean size of the DF and largest SF at the beginning of deviation was 7.4 ± 0.2 and 6.3 ± 0.1 mm, respectively. In conclusion, the characteristics of follicle deviation are similar between the animals that developed single or double DFs.     

Chiral symmetry breaking in sodium chlorate crystallizaton

Sodium chlorate (NaClO(3)) crystals are optically active although the molecules of the compound are not chiral. When crystallized from an aqueous solution while the solution is not stirred, statistically equal numbers of levo (L) and dextro (D) NaClO(3) crystals were found. When the solution was stirred, however, almost all of the NaClO(3) crystals (99.7 percent) in a particular sample had the same chirality, either levo or dextro. This result represents an experimental demonstration of chiral symmetry breaking or total spontaneous resolution on a macroscopic level brought about by autocatalysis and competition between L- and D-crystals.     

An extremely luminous panchromatic outburst from the nucleus of a distant galaxy

Variable x-ray and γ-ray emission is characteristic of the most extreme physical processes in the universe. We present multiwavelength observations of a unique γ-ray-selected transient detected by the Swift satellite, accompanied by bright emission across the electromagnetic spectrum, and whose properties are unlike any previously observed source. We pinpoint the event to the center of a small, star-forming galaxy at redshift z = 0.3534. Its high-energy emission has lasted much longer than any γ-ray burst, whereas its peak luminosity was ～100 times higher than bright active galactic nuclei. The association of the outburst with the center of its host galaxy suggests that this phenomenon has its origin in a rare mechanism involving the massive black hole in the nucleus of that galaxy.     

Chromosomal aberrations induced in barley by LSD

Seeds of hulled barley (Hordeum vulgare) were germinated and then treated with LSD. Preparations of squashed root tips stained with Feulgen revealed extensive chromosomal aberrations, most of which were chromosome breaks. Nearly half of the breaks occurred in the region of the primary constriction.     

A molecular switch and proton wire synchronize the active sites in thiamine enzymes

Thiamine diphosphate (ThDP) is used as a cofactor in many key metabolic enzymes. We present evidence that the ThDPs in the two active sites of the E1 (EC 1.2.4.1) component of the pyruvate dehydrogenase complex communicate over a distance of 20 angstroms by reversibly shuttling a proton through an acidic tunnel in the protein. This "proton wire" permits the co-factors to serve reciprocally as general acid/base in catalysis and to switch the conformation of crucial active-site peptide loops. This synchronizes the progression of chemical events and can account for the oligomeric organization, conformational asymmetry, and "ping-pong" kinetic properties of E1 and other thiamine-dependent enzymes.     

Atmospheric carbon tetrachloride: another man-made pollutant

On the basis of an analysis of historic worldwide emissions and removal mechanisms for carbon tetrachloride, a possible precursor for stratospheric ozone destruction, it has been demonstrated that the present atmospheric loading and distribution of carbon tetrachloride is primarily attributable to man-made emissions and no natural sources need be invoked to explain its presence in the atmosphere.     

Responses of cowpea (Vigna unguiculata (L.) Walp.) and mung bean (Vigna radiata (L.) Wilczek) to irrigation

Summary Cowpea and mung bean were subjected to three irrigation schedules during summer dry months (May–June). In general, cowpea had higher rates of net photosynthesis (P _n ,Figs. 1, 2), dark respiration (R _d ,Table 1), absorption of photosynthetically active radiation (PAR, Table 2), and growth (Fig. 7) than mung bean. Mung bean reflected more PAR and maintained a slightly cooler canopy than cowpea (Table 2). Moisture stress decreased P _n , R _d ,absorption coefficient of PAR, evaporative cooling and growth in both the species. However, the reductions in P _n rates of stressed leaves were more than the decreases in R _d .Restoration of water supply to stressed cowpea resulted in a more rapid recovery of growth as compared to mung bean.