1,277 research outputs found
(E,E)-N1,N2-Bis(2,6-difluorobenzylidene)ethane-1,2-diamine.
The asymmetric unit of the title compound, C16H12F4N2, comprises half of the potentially bidentate Schiff base ligand, with an inversion centre located at the mid-point of the central C—C bond. The crystal packing is stabilized by intermolecular C—H⋯N and π–π interactions [centroid–centroid distance = 3.6793 (12) Å and interplanar spacing = 3.4999 (7) Å]
Sequence variation in mitochondrial cox1 and nad1 genes of ascaridoid nematodes in cats and dogs from Iran
The study was conducted to determine the sequence variation in two mitochondrial genes, namely cytochrome c oxidase 1 (pcox1) and NADH dehydrogenase 1 (pnad1) within and among isolates of Toxocara cati, Toxocara canis and Toxascaris leonina. Genomic DNA was extracted from 32 isolates of T. cati, 9 isolates of T. canis and 19 isolates of T. leonina collected from cats and dogs in different geographical areas of Iran. Mitochondrial genes were amplified by polymerase chain reaction (PCR) and sequenced. Sequence data were aligned using the BioEdit software and compared with published sequences in GenBank. Phylogenetic analysis was performed using Bayesian inference and maximum likelihood methods. Based on pairwise comparison, intra-species genetic diversity within Iranian isolates of T. cati, T. canis and T. leonina amounted to 0-2.3, 0-1.3 and 0-1.0 for pcox1 and 0-2.0, 0-1.7 and 0-2.6 for pnad1, respectively. Inter-species sequence variation among the three ascaridoid nematodes was significantly higher, being 9.5-16.6 for pcox1 and 11.9-26.7 for pnad1. Sequence and phylogenetic analysis of the pcox1 and pnad1 genes indicated that there is significant genetic diversity within and among isolates of T. cati, T. canis and T. leonina from different areas of Iran, and these genes can be used for studying genetic variation of ascaridoid nematodes. © Cambridge University Press 2014
Sequence analysis of the second internal Transcribed spacer (ITS2) region of rDNA for species identification of trichostrongylus nematodes isolated from domestic livestock in Iran
Background: Infectivity of herbivores with Trichostrongylus nematodes is widespread in many countries, having a major economic impact on breeding, survivability, and productivity of domestic livestock. This study was carried out on Trichostrongylus species isolated from domestic livestock in order to develop an easy-to-perform method for species identification. Methods: Trichostrongylus isolates were collected from sheep, goat, cattle, and buffaloes in Khuzestan Province, southwest Iran. Primary species identification was carried out based on morphological characterization of male worms. PCR amplification of ITS2-rDNA region was performed on genomic DNA and the products were sequenced. Phylogenetic analysis of the nucleotide sequence data was conducted employing Bayesian Inference approach. Consequently, a restriction fragment length polymorphism (RFLP) profile was designed to differentiate Trichostrongylus species. Results: A consensus sequence of 238 nucleotides was deposited in the GenBank for Iranian isolates of Trichostrongylus species including T. colubriformis, T. capricola, T. probolurus and T. vitrinus. The designated RFLP using restriction enzyme TasI could readily differentiate among species having different ITS2 sequence. The molecular analysis was in concordance with morphological findings. Conclusion: Phylogenetic analysis indicated a close relationship among the sequences obtained in this study and reference sequence of relevant species. ITS2-RFLP with TasI is recommended for molecular differentiation of common Trichostrongylus species
The Future of Writing Teacher Education
This article provides background for the creation of the journal and suggestions for future submissions and directions
Federated Learning Using Variance Reduced Stochastic Gradient for Probabilistically Activated Agents
This paper proposes an algorithm for Federated Learning (FL) with a two-layer
structure that achieves both variance reduction and a faster convergence rate
to an optimal solution in the setting where each agent has an arbitrary
probability of selection in each iteration. In distributed machine learning,
when privacy matters, FL is a functional tool. Placing FL in an environment
where it has some irregular connections of agents (devices), reaching a trained
model in both an economical and quick way can be a demanding job. The first
layer of our algorithm corresponds to the model parameter propagation across
agents done by the server. In the second layer, each agent does its local
update with a stochastic and variance-reduced technique called Stochastic
Variance Reduced Gradient (SVRG). We leverage the concept of variance reduction
from stochastic optimization when the agents want to do their local update step
to reduce the variance caused by stochastic gradient descent (SGD). We provide
a convergence bound for our algorithm which improves the rate from
to by using a constant step-size. We
demonstrate the performance of our algorithm using numerical examples
Negative linear compression and expanding NH N bonds in an imidazoline compound.
The 3-dimensional network of NHN hydrogen bonds and ClCl hydrogen contacts in the crystal structure of 2-(3′-chlorophenyl)imidazoline exhibits an anomalous hydrostatic compression. The lengthening of hydrogen bonds NHN and some CHN contacts as well as their supramolecular architecture lead to anomalous expansion of the crystal along [x] and [y] on increasing pressure to 0.1 GPa. The mechanism of this phenomenon is due to the ‘stiffness’ of the NHN and ClCl interactions and ‘softness’ of other van der Waals contacts. Above 0.1 GPa all crystal directions become compressed. However, up to 1.20 GPa, the crystal remains in the same orthorhombic phase of polar space group Fdd2
4-Bromo-2-[(E)-(2-{2-[(2-{[(E)-5-bromo-2-hydroxybenzylidene]amino}phenyl)sulfanyl]ethylsulfanyl}phenyl)iminomethyl]phe-nol.
The asymmetric unit of the title compound, C28H22Br2N2O2S2, comprises half of a Schiff base ligand, the whole molecule being generated by a crystallographic inversion center located at the mid-point of the C—C bond of the central methylene segment. Intramolecular O—H⋯N and O—H⋯S hydrogen bonds make S(6) and S(5) ring motifs, respectively. In the crystal, there are no significant intermolecular interactions
2-{[(4-{[(2-Hydroxyphenyl)(phenyl)methylidene]amino}butyl)imino](phenyl) methyl}phenol.
The asymmetric unit of the title compound, C 30H 28N 2O 2, comprises half of a potential tetra-dentate Schiff base ligand; an inversion centre is situtated at the center of the butane-diamine spacer. The central methylene segment of the diamine spacer is disordered over two positions with a refined siteoccupancy ratio of 0.651 (7):0.349 (7). The phenyl ring and the hydroxysubstituted benzene ring are almost perpendicular to each other, with a dihedral angle of 87.90 (8) Å. intramolecular O - H⋯N hydrogen bonds make S(6) ring motifs
First molecular identification of Sarcocystis miescheriana (Protozoa, Apicomplexa) from wild boar (Sus scrofa) in Iran
Sarcocystis isolate obtained from the thigh muscle of a wild boar (Sus scrofa), captured from Gilan Province, northern Iran, was subjected to molecular analysis. Genomic DNA was obtained using a DNA extraction tissue kit and Polymerase chain reaction (PCR) for amplification of the 18S ribosomal DNA region yielded an 842. bp DNA band on agarose gel. Analysis of DNA sequencing by BLAST confirmed the isolate as Sarcocystis miescheriana and the sequence was deposited in GenBank by Accession No. GU395554. This is the first molecular identification of an isolate of S. miescheriana in Iran. © 2010 Elsevier Inc
Using Mendelian randomization to understand and develop treatments for neurodegenerative disease
Common neurodegenerative diseases are thought to arise from a combination of environmental and genetic exposures. Mendelian randomization is a powerful way to leverage existing genetic data to investigate causal relationships between risk factors and disease. In recent years, Mendelian randomization has gathered considerable traction in neurodegenerative disease research, providing valuable insights into the aetiology of these conditions. This review aims to evaluate the impact of Mendelian randomization studies on translational medicine for neurodegenerative diseases, highlighting the advances made and challenges faced. We will first describe the fundamental principles and limitations of Mendelian randomization and then discuss the lessons from Mendelian randomization studies of environmental risk factors for neurodegeneration. We will illustrate how Mendelian randomization projects have used novel resources to study molecular pathways of neurodegenerative disease and discuss the emerging role of Mendelian randomization in drug development. Finally, we will conclude with our view of the future of Mendelian randomization in these conditions, underscoring unanswered questions in this field
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