Effect of sowing dates and vernalization on Betavulgaris L. cv. Univers C-leaf structure

This research was conducted to study the effect of three different sowing dates (15th October, 15th November and 15th December) and two vernalization treatments (5 °C and −20 °C) on leaf structure of Betavulgaris L. cv. Univers. The obtained data are summarized as follows:The maximum values of the most studied parameters; lower epidermis + spongy tissue thickness, midrib, mesophyll tissue, vascular bundle, collenchymatous tissue and number of xylem vessels per arm were found as a result of 15th October sowing date treatment compared with the two other sowing dates. Furthermore, effect of the cooling treatments varied according to the recorded character, sowing date and cooling degree. Most of the vernalization treatments at early sowing dates increased the mesophyll tissue, midrib, number of vascular bundles per transverse section, vascular bundle thickness and number of xylem arms per transverse section.The two studied cooling treatments at 15th October sowing date increased both stomatal index and average number of stomata: average number of epidermis cells compared with the control. Furthermore, 15th October under −20 °C treatment led to small epidermal cells and stomata formation, straight epidermal cell walls and closed stomata in comparison to the control.     

Salt modulates vascular response through adenosine A2A receptor in eNOS-null mice: role of CYP450 epoxygenase and soluble epoxide hydrolase

High salt (HS) intake can change the arterial tone in mice, and the nitric oxide (NO) acts as a mediator to some of the receptors mediated vascular response. The main aim of this study was to explore the mechanism behind adenosine-induced vascular response in HS-fed eNOS(+/+) and eNOS(-/-) mice The modulation of vascular response by HS was examined using aortas from mice (eNOS(+/+) and eNOS(-/-)) fed 4% (HS) or 0.45% (NS) NaCl-diet through acetylcholine (ACh), NECA (adenosine-analog), CGS 21680 (A(2A) AR-agonist), MS-PPOH (CYP epoxygenase-blocker; 10(-5) M), AUDA (sEH-blocker; 10(-5) M), and DDMS (CYP4A-blocker; 10(-5) M). ACh-response was greater in HS-eNOS(+/+) (+59.3 ± 6.3%) versus NS-eNOS(+/+) (+33.3 ± 8.0%; P < 0.05). However, there was no response in both HS-eNOS(-/-) and NS-eNOS(-/-). NECA-response was greater in HS-eNOS(-/-) (+37.4 ± 3.2%) versus NS-eNOS(-/-) (+7.4.0 ± 3.8%; P < 0.05). CGS 21680-response was also greater in HS-eNOS(-/-) (+45.4 ± 5.2%) versus NS-eNOS(-/-)(+5.1 ± 5.0%; P < 0.05). In HS-eNOS(-/-), the CGS 21680-response was reduced by MS-PPOH (+7.3 ± 3.2%; P < 0.05). In NS-eNOS(-/-), the CGS 21680-response was increased by AUDA (+38.2 ± 3.3%; P < 0.05) and DDMS (+30.1 ± 4.1%; P < 0.05). Compared to NS, HS increased CYP2J2 in eNOS(+/+) (35%; P < 0.05) and eNOS(-/-) (61%; P < 0.05), but decreased sEH in eNOS(+/+) (74%; P < 0.05) and eNOS(-/-) (40%; P < 0.05). Similarly, CYP4A decreased in HS-eNOS(+/+) (35%; P < 0.05) and HS-eNOS(-/-) (34%; P < 0.05). These data suggest that NS causes reduced-vasodilation in both eNOS(+/+) and eNOS(-/-) via sEH and CYP4A. However, HS triggers possible A(2A)AR-induced relaxation through CYP epoxygenase in both eNOS(+/+) and eNOS(-/-).     

Drosophila Heterochromatin Protein 1 (HP1)/Origin Recognition Complex (ORC) Protein Is Associated with HP1 and ORC and Functions in Heterochromatin-induced Silencing

Heterochromatin protein 1 (HP1) is a conserved component of the highly compact chromatin of higher eukaryotic centromeres and telomeres. Cytogenetic experiments in Drosophila have shown that HP1 localization into this chromatin is perturbed in mutants for the origin recognition complex (ORC) 2 subunit. ORC has a multisubunit DNA-binding activity that binds origins of DNA replication where it is required for origin firing. The DNA-binding activity of ORC is also used in the recruitment of the Sir1 protein to silence nucleation sites flanking silent copies of the mating-type genes in Saccharomyces cerevisiae. A fraction of HP1 in the maternally loaded cytoplasm of the early Drosophila embryo is associated with a multiprotein complex containing Drosophila melanogaster ORC subunits. This complex appears to be poised to function in heterochromatin assembly later in embryonic development. Here we report the identification of a novel component of this complex, the HP1/ORC-associated protein. This protein contains similarity to DNA sequence-specific HMG proteins and is shown to bind specific satellite sequences and the telomere-associated sequence in vitro. The protein is shown to have heterochromatic localization in both diploid interphase and mitotic chromosomes and polytene chromosomes. Moreover, the gene encoding HP1/ORC-associated protein was found to display reciprocal dose-dependent variegation modifier phenotypes, similar to those for mutants in HP1 and the ORC 2 subunit.     

Monkeys and toads define areas of endemism on Sulawesi

Abstract.— Ecological or geological phenomena can impose limits on geographic diversification that cause biogeographical patterns of distantly related but sympatrically occurring taxa to be similar. Concordant patterns of diversity facilitate conservation management because strategic designation of protected areas can capture complementary rather than redundant components of variation. Here we demonstrate that on the biodiverse Indonesian island of Sulawesi, seemingly idiosyncratic distributions of diversity in endemic monkeys (Macaca species) and toads (Bufo celebensis) are actually virtually identical on a fine geographic scale. It appears that range fragmentation has generated seven multi-taxon areas of genetic endemism, each of which should be targeted for conservation. Joint consideration of molecular phylogeography, morphology, and demography helps resolve apparent contradictions in paraphyletic macaque mitochondrial DNA and in undifferentiated toad morphology, and facilitates an understanding of biogeography and conservation genetics of Sulawesi fauna.     

Vanadium chemistry and biochemistry of relevance for use of vanadium compounds as antidiabetic agents

The stability of 11 vanadium compounds is tested under physiological conditions and in administration fluids. Several compounds including those currently used as insulin-mimetic agents in animal and human studies are stable upon dissolution in distilled water but lack such stability in distilled water at pH7. Complex lability may result in decomposition at neutral pH and thus may compromise the effectiveness of these compounds as therapeutic agents; Even well characterized vanadium compounds are surprisingly labile. Sufficiently stable complexes such as the VEDTA complex will only slowly reduce, however, none of the vanadium compounds currently used as insulin-mimetic agents show the high stability of the VEDTA complex. Both the bis(maltolato)oxovanadium(IV) and peroxovanadium complexes extend the insulin-mimetic action of vanadate in reducing cellular environments probably by increased lifetimes under physiological conditions and/or by decomposing to other insulin mimetic compounds. For example, treatment with two equivalents of glutathione or other thiols the (dipicolinato)peroxovanadate(V) forms 9dipicolinato)oxovanadate(V) and vanadate, which are both insulin-mimetic vanadium(V) compounds and can continue to act. The reactivity of vanadate under physiological conditions effects a multitude of biological responses. Other vanadium complexes may mimic insulin but not induce similar responses if the vanadate formation is blocked or reduced. We conclude that three properties, stability, lability and redox chemistry are critical to prolong the half-life of the insulin-mimetic form of vanadium compounds under physiological conditions and should all be considered in development of vanadium-based oral insulin-mimetic agents.Abbreviations ADP adenosine 5-diphosphate - ATP adenosine 5-triphosphate - ADP-V adenosine 5-diphosphate-vanadate - bpV bis(peroxo)oxovanadium(V) - (bpV)2 bis(peroxo)oxovanadium(V) dimer - bpVpic bis(peroxo)picolinatooxovanadate(V) - ¹³C carbon-13 - EDTA ethylenediaminetetraacetic acid - EPR electron paramagnetic resonance - EXSY exchange spectroscopy - ¹H proton - HSG glutathione - NAD -nicotinamide adenine dinucleotide - NADP -nicotinamide adenine dinucleotide phosphate - NADV -nicotinamide adenine dinucleotide vanadate - NMR nuclear magnetic resonance (also referred to as magnetic resonance imaging) - pVdipic (dipicolinato)peroxovanadate(V) - Vcit (citrato)dioxovanadate(V) - VEDTA (ethylenediaminetetraacetato)dioxovanadate(V) - Vmalto bis(maltolato)-oxovanadium(IV) - Voxal bis(oxalato)dioxovanadate(V) - ⁵¹V vanadium-51 - V₁ vanadate monomer - V₂ vanadate dimer - V₄ vanadate tetramer - V₅ vanadate pentamer - UV-vis spectroscopy ultraviolet-visible spectroscopy     

Cooperative object transport with a swarm of e-puck robots: robustness and scalability of evolved collective strategies

Cooperative object transport in distributed multi-robot systems requires the coordination and synchronisation of pushing/pulling forces by a group of autonomous robots in order to transport items that cannot be transported by a single agent. The results of this study show that fairly robust and scalable collective transport strategies can be generated by robots equipped with a relatively simple sensory apparatus (i.e. no force sensors and no devices for direct communication). In the experiments described in this paper, homogeneous groups of physical e-puck robots are required to coordinate and synchronise their actions in order to transport a heavy rectangular cuboid object as far as possible from its starting position to an arbitrary direction. The robots are controlled by dynamic neural networks synthesised using evolutionary computation techniques. The best evolved controller demonstrates an effective group transport strategy that is robust to variability in the physical characteristics of the object (i.e. object mass and size of the longest object’s side) and scalable to different group sizes. To run these experiments, we designed, built, and mounted on the robots a new sensor that returns the agents’ displacement on a 2D plane. The study shows that the feedback generated by the robots’ sensors relative to the object’s movement is sufficient to allow the robots to coordinate their efforts and to sustain the transports for an extended period of time. By extensively analysing successful behavioural strategies, we illustrate the nature of the operational mechanisms underpinning the coordination and synchronisation of actions during group transport.     

Effect of coligands on biodistribution characteristics of ternary ligand 99mTc complexes of a HYNIC-conjugated cyclic RGDfK dimer

This report describes biodistribution characteristics of three ternary ligand complexes [(99m)Tc(SQ168)(tricine)(L)] (SQ168 = [2-[[[5-[carboonyl]-2-pyridinyl]hydrazono]methyl]-benzenesulfonic acid]-Glu(cyclo{Lys-Arg-Gly-Asp-d-Phe})-cyclo{Lys-Arg-Gly-Asp-d-Phe}; L = TPPTS (trisodium triphenylphosphine-3,3',3' '-trisulfonate), ISONIC (isonicotinic acid) and PDA (2,5-pyridinedicarboxylic acid)) in athymic nude mice bearing MDA-MB-435 human breast cancer xenografts. Ternary ligand complexes [(99m)Tc(SQ168)(tricine)(L)] (L = TPPTS, ISONIC and PDA) were prepared and were analyzed by a reversed HPLC method. Surprisingly, coligands have little impact on log P values of their ternary ligand (99m)Tc complexes even though HPLC retention times suggest that [(99m)Tc(SQ168)(tricine)(PDA)] and [(99m)Tc(SQ168)(tricine)(ISONIC)] are more hydrophilic than [(99m)Tc(SQ168)(tricine)(TPPTS)]. The results from biodistribution studies indicated that excretion kinetics of the (99m)Tc-labeled cyclic RGDfK dimer can be modified by the choice of coligand. The fact that all three radiotracers show high tumor uptake during the 2 h study period suggests that the coligand has minimal effect on the tumor targeting capability of the (99m)Tc-labeled cyclic RGDfK dimer. Results from the blocking experiment suggest that the tumor localization of the (99m)Tc-labeled cyclic RGDfK dimer is integrin alpha(v)beta(3)-mediated. On the basis of their liver uptake and tumor/liver ratios, we believe that PDA has the advantage over TPPTS and ISONIC for the (99m)Tc-labeling of HYNIC-biomolecule conjugates.     

Synthesis of Aldehydo-sugar Derivatives of Pyrazoloquinoline as Inhibitors of Herpes Simplex Virus Type 1 Replication

Synthesis of a novel series of structurally related pyrazoloquinoline nucleosides is described. All the newly synthesized compounds were examined for their in vitro antiviral activity against herpes simplex type-1 as shown by two different bioassays, namely; crystal violet staining or the MTS tetrazolium dye measurement. The acute toxicity (LD50) values of the biologically active compounds were determined.     

Examining the critical roles of human CB2 receptor residues Valine 3.32 (113) and Leucine 5.41 (192) in ligand recognition and downstream signaling activities

We performed molecular modeling and docking to predict a putative binding pocket and associated ligand–receptor interactions for human cannabinoid receptor 2 (CB2). Our data showed that two hydrophobic residues came in close contact with three structurally distinct CB2 ligands: CP-55,940, SR144528 and XIE95-26. Site-directed mutagenesis experiments and subsequent functional assays implicated the roles of Valine residue at position 3.32 (V113) and Leucine residue at position 5.41 (L192) in the ligand binding function and downstream signaling activities of the CB2 receptor. Four different point mutations were introduced to the wild type CB2 receptor: V113E, V113L, L192S and L192A. Our results showed that mutation of Val113 with a Glutamic acid and Leu192 with a Serine led to the complete loss of CB2 ligand binding as well as downstream signaling activities. Substitution of these residues with those that have similar hydrophobic side chains such as Leucine (V113L) and Alanine (L192A), however, allowed CB2 to retain both its ligand binding and signaling functions. Our modeling results validated by competition binding and site-directed mutagenesis experiments suggest that residues V113 and L192 play important roles in ligand binding and downstream signaling transduction of the CB2 receptor.     

DIVERSITY IN GUT MICROFLORA OF Helicoverpa armigera POPULATIONS FROM DIFFERENT REGIONS IN RELATION TO BIOLOGICAL ACTIVITY OF Bacillus thuringiensis δ‐ENDOTOXIN Cry1Ac

Transgenic crops expressing toxin proteins from Bacillus thuringiensis (Bt) have been deployed on a large scale for management of Helicoverpa armigera. Resistance to Bt toxins has been documented in several papers, and therefore, we examined the role of midgut microflora of H. armigera in its susceptibility to Bt toxins. The susceptibility of H. armigera to Bt toxin Cry1Ac was assessed using Log‐dose‐Probit analysis, and the microbial communities were identified by 16S rRNA sequencing. The H. armigera populations from nine locations harbored diverse microbial communities, and had some unique bacteria, suggesting a wide geographical variation in microbial community in the midgut of the pod borer larvae. Phylotypes belonging to 32 genera were identified in the H. armigera midgut in field populations from nine locations. Bacteria belonging to Enterobacteriaceae (Order Bacillales) were present in all the populations, and these may be the common members of the H. armigera larval midgut microflora. Presence and/or absence of certain species were linked to H. armigera susceptibility to Bt toxins, but there were no clear trends across locations. Variation in susceptibility of F₁ neonates of H. armigera from different locations to the Bt toxin Cry1Ac was found to be 3.4‐fold. These findings support the idea that insect migut microflora may influence the biological activity of Bt toxins.