97 research outputs found

    Effect of pot size, planting date and genotype on minituber production of Marfona potato cultivar

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    This study was carried out to evaluate the effects of pot size, planting date and type of genotype on mini-tuber production of Marfona potato cultivar (Solanum tuberosum L.) in greenhouse conditions.Four genotypes (M-129, M-128P, M-127P and M-124P) originated from virus free sprouts and a genotype of the same cultivar (Marfona) originated from apical meristem, in 3 sizes of pot and 3 planting datewere investigated. The results showed that using larger pots of 3-liter has no advantage and pots smaller than 2-liter is not suitable for mini-tuber production. Also, time of Nov 18 was the best of datefor planting of potato in studied conditions and delay in date of planting reduced the mini-tuber production. The reduction in number of mini-tubers and growing period was greater for the genotype M-129 compared with the other potato genotypes. Furthermore, higher numbers of mini-tubers were produced by the M-127P and M-124P genotypes and M-127P had the highest total weight of mini-tubers.However the number of mini-tubers per plant was higher for genotypes originated from meristem culture than genotypes obtained from sprouts. It seems that genotypes originated from potato sprouts are not as efficient as the apical meristem ones. On the other hand, later genotype showed more homogenous in growth rate and phenotype

    Neutron diffraction reveals sequence-specific membrane insertion of pre-fibrillar islet amyloid polypeptide and inhibition by rifampicin

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    AbstractHuman islet amyloid polypeptide (hIAPP) forms amyloid deposits in non-insulin-dependent diabetes mellitus (NIDDM). Pre-fibrillar hIAPP oligomers (in contrast to monomeric IAPP or mature fibrils) increase membrane permeability, suggesting an important role in the disease. In the first structural study of membrane-associated hIAPP, lamellar neutron diffraction shows that oligomeric hIAPP inserts into phospholipid bilayers, and extends across the membrane. Rifampicin, which inhibits hIAPP-induced membrane permeabilisation in functional studies, prevents membrane insertion. In contrast, rat IAPP (84% identical to hIAPP, but non-amyloidogenic) does not insert into bilayers. Our findings are consistent with the hypothesis that membrane-active pre-fibrillar hIAPP oligomers insert into beta cell membranes in NIDDM

    Coordination chemistry of amide-functionalised tetraazamacrocycles: structural, relaxometric and cytotoxicity studies

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    Three different tetraazamacrocyclic ligands containing four amide substituents that feature groups (namely allyl, styryl and propargyl groups) suitable for polymerisation have been synthesised. Gadolinium(III) complexes of these three ligands have been prepared as potential monomers for the synthesis of polymeric MRI contrast agents. To assess the potential of these monomers as MRI contrast agents, their relaxation enhancement properties and cytotoxicity have been determined. A europium(III) complex of one of these ligands (with propargyl substituents) is also presented together with its PARACEST properties. In addition, to gain further insight into the coordination chemistry of the tetra-propargyl substituted ligand, the corresponding zinc(II) and cadmium(II) complexes have been prepared. The X-ray crystal structures of the tetra-propargyl ligand and its corresponding gadolinium(III), zinc(II) and cadmium(II) complexes are also presented

    Conformational effects on the Circular Dichroism of Human Carbonic Anhydrase II: a multilevel computational study

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    Circular Dichroism (CD) spectroscopy is a powerful method for investigating conformational changes in proteins and therefore has numerous applications in structural and molecular biology. Here a computational investigation of the CD spectrum of the Human Carbonic Anhydrase II (HCAII), with main focus on the near-UV CD spectra of the wild-type enzyme and it seven tryptophan mutant forms, is presented and compared to experimental studies. Multilevel computational methods (Molecular Dynamics, Semiempirical Quantum Mechanics, Time-Dependent Density Functional Theory) were applied in order to gain insight into the mechanisms of interaction between the aromatic chromophores within the protein environment and understand how the conformational flexibility of the protein influences these mechanisms. The analysis suggests that combining CD semi empirical calculations, crystal structures and molecular dynamics (MD) could help in achieving a better agreement between the computed and experimental protein spectra and provide some unique insight into the dynamic nature of the mechanisms of chromophore interactions

    Epigenetic perturbations in the pathogenesis of mustard toxicity; hypothesis and preliminary results

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    Among the most readily available chemical warfare agents, sulfur mustard (SM), also known as mustard gas, has been the most widely used chemical weapon. SM causes debilitating effects that can leave an exposed individual incapacitated for days to months; therefore delayed SM toxicity is of much greater importance than its ability to cause lethality. Although not fully understood, acute toxicity of SM is related to reactive oxygen and nitrogen species, oxidative stress, DNA damage, poly(ADP-ribose) polymerase (PARP) activation and energy depletion within the affected cell. Therefore several antioxidants and PARP inhibitors show beneficial effects against acute SM toxicity. The delayed toxicity of SM however, currently has no clear mechanistic explanation. One third of the 100,000 Iranian casualties are still suffering from the detrimental effects of SM in spite of the extensive treatment. We, therefore, made an attempt whether epigenetic aberrations may contribute to pathogenesis of mustard poisoning. Preliminary evidence reveals that mechlorethamine (a nitrogen mustard derivative) exposure may not only cause oxidative stress, DNA damage, but epigenetic perturbations as well. Epigenetic refers to the study of changes that influence the phenotype without causing alteration of the genotype. It involves changes in the properties of a cell that are inherited but do not involve a change in DNA sequence. It is now known that in addition to mutations, epimutations contribute to a variety of human diseases. Under light of preliminary results, the current hypothesis will focus on epigenetic regulations to clarify mustard toxicity and the use of drugs to correct possible epigenetic defects

    Acaricide Residues in Laying Hens Naturally Infested by Red Mite Dermanyssus gallinae

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    In the poultry industry, control of the red mite D. gallinae primarily relies worldwide on acaricides registered for use in agriculture or for livestock, and those most widely used are carbamates, followed by amidines, pyrethroids and organophosphates. Due to the repeated use of acaricides - sometimes in high concentrations - to control infestation, red mites may become resistant, and acaricides may accumulate in chicken organs and tissues, and also in eggs. To highlight some situations of misuse/abuse of chemicals and of risk to human health, we investigated laying hens, destined to the slaughterhouse, for the presence of acaricide residues in their organs and tissues. We used 45 hens from which we collected a total of 225 samples from the following tissues and organs: skin, fat, liver, muscle, hearth, and kidney. In these samples we analyzed the residual contents of carbaryl and permethrin by LC-MS/MS

    Acute and delayed sulfur mustard toxicity; novel mechanisms and future studies

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    Sulfur mustard (SM), also known as mustard gas, has been the most widely used chemical weapon. The toxicity of SM as an incapacitating agent is of much greater importance than its ability to cause lethality. Acute toxicity of SM is related to reactive oxygen and nitrogen species, DNA damage, poly(ADP-ribose) polymerase activation and energy depletion within the affected cell. Therefore melatonin shows beneficial effects against acute SM toxicity in a variety of manner. It scavenges most of the oxygen- and nitrogen-based reactants, inhibits inducible nitric oxide synthase, repairs DNA damage and restores cellular energy depletion. The delayed toxicity of SM however, currently has no mechanistic explanation. We propose that epigenetic aberrations may be responsible for delayed detrimental effects of mustard poisoning. Epigenetic refers to the study of changes that influence the phenotype without causing alteration of the genotype. It involves changes in the properties of a cell that are inherited but do not involve a change in DNA sequence. It is now known that in addition to genetic mutations, epimutations can also involve in the pathogenesis of a variety of human diseases. Several actions of melatonin are now delineated by epigenetic actions including modulation of histone acetylation and DNA methylation. Future studies are warranted to clarify whether epigenetic mechanisms are involved in pathogenesis of delayed sulfur mustard toxicity and melatonin alleviates delayed toxicity of this warfare agent

    Qur’anic Ethics for Environmental Responsibility: Implications for Business Practice

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    Despite the growing interest in examining the role of religious beliefs as a guide towards environmental conscious actions, there is still a lack of research informed by an analysis of divine messages. This deficiency includes the extent to which ethics for environmental responsibility are promoted within textual divine messages; types of environmental themes promoted within the text of divine messages; and implications of such religious environmental ethics for business practice. The present study attempts to fill this gap by conducting a thorough content analysis of environmental themes within the divine message of Muslims (the Qur’an) focusing on their related ethical aspects and business implications. The analysis has revealed 675 verses in 84 chapters throughout all 30 parts of the Qur’an, with environmental content relating to the core components of the natural world, i.e. human beings, water, air, land, plants, animals, and other natural resources. This environmental content and its related ethics are grounded on the belief that humans are vicegerents of God on the earth and their behaviours and actions are motivated by earthly and heavenly rewards. Implications of these findings for different sectors/businesses are also highlighted
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