Variation in calcification rate of Acropora downingi relative to seasonal changes in environmental conditions in the northeastern Persian Gulf

There is a strong interest in understanding how coral calcification varies with changing environmental conditions, especially given the projected changes in temperature and aragonite saturation due to climate change. This study explores in situ variation in calcification rates of Acropora downingi in the northeastern Persian Gulf relative to seasonal changes in temperature, irradiance and aragonite saturation state (Ω _arag). Calcification rates of A. downingi were highest in the spring and lowest in the winter, and intra-annual variation in calcification rate was significantly related to temperature (r ² = 0.30) and irradiance (r ² = 0.36), but not Ω _arag (r ² = 0.02). Seasonal differences in temperature are obviously confounded by differences in other environmental conditions and vice versa. Therefore, we used published relationships from experimental studies to establish which environmental parameter(s) (temperature, irradiance, and/or Ω _arag) placed greatest constraints on calcification rate (relative to the maximum spring rate) in each season. Variation in calcification rates was largely attributable to seasonal changes in irradiance and temperature (possibly ~57.4 and 39.7% respectively). Therefore, we predict that ocean warming may lead to increased rates of calcification during winter, but decelerate calcification during spring, fall and especially summer, resulting in net deceleration of calcification for A. downingi in the Persian Gulf.

     

Synthesis,cytotoxicity assessment,and interaction and docking of novel palladium(II) complexes of imidazole derivatives with human serum albumin

Imidazole analogs are the agents that attract both bioinorganic chemist and drug designer. Numerous methods have been proposed for synthesis of imidazole derivatives. In this study, a series of heterocyclic system with p-conjugated system such as 2-aryl-imidazo[4,5-f][1,10]phenanthroline analogs were synthesized. Then, three new palladium(II) complexes containing 2-(Furan-2-yl)-1H-Imidazo[4,5-f][1,10]Phenanthroline (FIP) and 2-(thiophen-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (TIP) ligands were synthesized. The structures of the compounds, [Pd(Phen)(TIP)](NO₃)₂, [Pd(Phen)(FIP)](NO₃)₂, and [Pd(FIP)₂]Cl were determined by spectroscopic methods and elemental analysis. Biological activity of the complexes synthesized was assessed against chronic myelogenous leukemia cell line, K562. Also, the interactions of human serum albumin with complexes were investigated using isothermal titration in the Tris buffer, pH 7.4. According to the results obtained, it was found that there is a set of six binding sites for these complexes on HSA with positive cooperativity in the binding process. Docking technique was also applied to confirm the experimental results. The results showed that smaller complexes have higher interaction affinity.     

Ant colony based constrained workflow scheduling for heterogeneous computing systems

The problem of constrained workflow scheduling on heterogeneous computing systems has been of major interest in the recent years. The user requirements are described by defining constraints on the workflow makespan and/or its execution cost. The uncertainty in the activity execution path and the dynamicity in the resource workload may cause some run-time changes of the makespan or cost. To prohibit run-time constraint violation, the system needs robust schedules. In this paper, probability of violation (POV) of constraints is proposed as a criterion for the schedule robustness. An ant colony system is then used to minimize an aggregation of violation of constraints and the POV. Simulation results on real world workflows show the effectiveness of the proposed method in finding feasible schedules. The results also indicate that the proposed method decreases the POV, as well as the expected penalty at run-time.     

Intracellular Distribution of Rubella Virus Nonstructural Protein P150

Antiserum prepared against an amino-terminal fragment of rubella virus (RUB) nonstructural polyprotein was used to study RUB-infected Vero cells. Replicase protein P150 was associated with vesicles and vacuoles of endolysosomal origin and later with large, convoluted, tubular membrane structures. Newly incorporated bromouridine was associated with the same structures and specifically with small membrane invaginations, spherules, indicating that these structures may be the sites of viral RNA synthesis.     

PCR-based detection and eradication of mycoplasmal infections from various mammalian cell lines: a local experience

A total of 200 cell lines including different human, monkey, mice, hamster and rat cell types were examined for mycoplasma infection status. PCR assay using generic-specific universal primers showed that 40 (20%) of the cell lines are contaminated with mycoplasma. Employment of species-specific primers within these infected cell lines revealed infection with M. hyorhinis (42.5%), M. fermentas (37.5%), M. arginini (37.5%), M. orale (12.5%) and A. laidlawii (7.5%). A number of the cultures were coinfected with 2 or 3 different species. Contaminated samples were treated with BM-Cyclin, Ciprofloxacin and mycoplasma removal agent (MRA). Mycoplasma eradication was subsequently checked by PCR following 2 weeks continuous culture of treated cells in antibiotic free culture medium. Mycoplasmal infections were eradicated in 100, 70 and 42% of infected cell lines when the samples were treated with BM-Cyclin, MRA and Ciprofloxacin, respectively. However, 12% (BM-Cyclin), 62.5% (MRA) and 82.5% (Ciprofloxacin) of mycoplasma regrowth was observed 4 months after the treatment. Notably, the risk of spontaneous culture death was 17.5, 12.5 and 0% for BM-Cyclin, MRA and Ciprofloxacin, respectively.     

Kavosh: a new algorithm for finding network motifs

Background  

Complex networks are studied across many fields of science and are particularly important to understand biological processes. Motifs in networks are small connected sub-graphs that occur significantly in higher frequencies than in random networks. They have recently gathered much attention as a useful concept to uncover structural design principles of complex networks. Existing algorithms for finding network motifs are extremely costly in CPU time and memory consumption and have practically restrictions on the size of motifs.     

Lignicolous fungi from northern Serbia as natural sources of antioxidants

As a result of an interest in natural derived metabolites, lignicolous fungi have taken on great importance in biochemical investigations. In the present study, antioxidative screening analyses have included in vitro testing of different extracts (aqueous, methanol, chloroform) of four fungal species using three different assays: Fe²⁺/ascorbate-induced lipid peroxidation by TBA assay, the neutralisation of OH· radicals and the radical scavenging capacity with the DPPHk]assay. TLC analysis confirmed the existance of phenolics in the extracts, but also indicates the presence of some other compounds. The obtained results indicate that MeOH extracts manifested a degree of activity higher than that of CHCl₃ extracts. With respect to antioxidative activity, the extracts can be ranged in the following declining order: G. lucidum, G. applanatum, M. giganteus and F. velutipes. These results suggest that analyzed fungi are of potential interest as sources of strong natural antioxidants that could be used in the food industries and nutrition.     

Mucor hiemalis: a new source for uricase production

Summary One hundred and sixty-five strains of microorganisms with the ability to grow in a medium containing uric acid as a major source of nitrogen were isolated from soil samples during a screening program. Among them, a zygomycete fungus with well-developed columellae was recognized to produce high levels of the enzyme in a short time. Classification of the isolated fungus was carried out according to the morphological and culture characteristics of the organism, and it was identified as Mucor hiemalis. The fungus was able to produce an intracellular urate oxidase in a fermentation medium mainly containing uric acid. Optimized composition of the medium consisted of (l⁻¹ of distilled water) uric acid, 7.0 g; maltose, 6.0 g; Vogel stock solution, 20 and 1 ml of 0.5 M copper sulphate. The optimum pH and temperature for uricase production in the optimized medium were pH 6 and 30 °C, respectively.