949 research outputs found

    Cladistic relationships within the genus Cinnamomum (Lauraceae) in Taiwan based on analysis of leaf morphology and inter-simple sequence repeat (ISSR) and internal transcribed spacer (ITS) molecular markers

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    We examined leaf morphological characteristics, ISSR (inter-simple sequence repeat) genetic polymorphisms and ITS (rDNA internal transcribed spacer) molecular markers in 12 endemic species of Cinnamomum in Taiwan to determine their cladistic relationships. The leaf morphology and ISSR data support the division of the genus into sections Camphora and Cinnamomum. The genetic relationship between Cinnamomum camphora and Cinnamomum micranthum is very close; both species share a specific 11 bp deletion in their ITS sequences. A close relationship between Cinnamomum insularimontanum and Cinnamomum macrostemon was supported by leaf morphology, ISSR and ITS data and the ITS analysis indicates that Cinnamomum subavenium is closely related to these two species. The ITS analysis also indicates that Cinnamomum japonicum, Cinnamomum austrosinense and Cinnamomum reticulatum are closely related. Leaf morphology and ISSRs also support the kinship between C. japonicum and C. austrosinense. The ITS data support a close cluster consisting of C. osmophloeum, C. camphora and C. micranthum, suggesting that Cinnamomum osmophloeum might be a key species in the evolutionary transition from section Camphora to section  Cinnamomum. Our results demonstrate that ISSR and ITS markers can clearly identify the 12 endemic Cinnamomum species in Taiwan.Key words: Cinnamomum, morphology, taxonomy, ISSR (inter-simple sequence repeat), ITS (internal transcribed spacer), phylogeny

    An unusual S-adenosylmethionine synthetase gene from dinoflagellate is methylated

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    Background: S-Adenosylmethionine synthetase (AdoMetS) catalyzes the formation of S-Adenosylmethionine (AdoMet), the major methyl group donor in cells. AdoMet-mediated methylation of DNA is known to have regulatory effects on DNA transcription and chromosome structure. Transcription of environmental-responsive genes was demonstrated to be mediated via DNA methylation in dinoflagellates. Results: A full-length cDNA encoding AdoMetS was cloned from the dinoflagellate Crypthecodinium cohnii. Phylogenetic analysis suggests that the CcAdoMetS gene, is associated with the clade of higher plant orthrologues, and not to the clade of the animal orthrologues. Surprisingly, three extra stretches of residues ( 8 to 19 amino acids) were found on CcAdoMetS, when compared to other members of this usually conserved protein family. Modeled on the bacterial AdeMetS, two of the extra loops are located close to the methionine binding site. Despite this, the CcAdoMetS was able to rescue the corresponding mutant of budding yeast. Southern analysis, coupled with methylation-sensitive and insensitive enzyme digestion of C. cohnii genomic DNA, demonstrated that the AdoMetS gene is itself methylated. The increase in digestibility of methylation-sensitive enzymes on AdoMet synthetase gene observed following the addition of DNA methylation inhibitors L-ethionine and 5-azacytidine suggests the presence of cytosine methylation sites within CcAdoMetS gene. During the cell cycle, both the transcript and protein levels of CcAdoMetS peaked at the G1 phase. L- ethionine was able to delay the cell cycle at the entry of S phase. A cell cycle delay at the exit of G2/M phase was induced by 5-azacytidine. Conclusion: The present study demonstrates a major role of AdoMet-mediated DNA methylation in the regulation of cell proliferation and that the CcAdoMetS gene is itself methylated

    De novo transcriptome analysis for mechanistic study of organotin-mediated endocrine disruption in Reishia Clavigera

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    Poster presentation: P-63Human ImpactsMany endocrine disrupting compounds are bioaccumulative and toxic to a wide range of marine organisms, leading to reproductive impairment, development of cancer and abnormal metabolism. For instance, organotin compounds (OTs) such as tributyltin and triphenyltin can induce the development of imposex (i.e., superimposition of male sexual organs) in females of over 200 gastropod species. OTs have been widely used as biocides in antifouling paints and industrial applications. Thus they have been released into the marine environment, posing risks to non-target marine organisms and human health. Although many studies have been conducted to ...postprin

    Additional molecular testing of saliva specimens improves the detection of respiratory viruses

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    The association between internet addiction and psychiatric co-morbidity: A meta-analysis

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    Background: This study evaluates the association between Internal Addiction (IA) and psychiatric co-morbidity in the literature.Methods: Meta-analyses were conducted on cross-sectional, case-control and cohort studies which examined the relationship between IA and psychiatric co-morbidity. Selected studies were extracted from major online databases. The inclusion criteria are as follows: 1) studies conducted on human subjects; 2) IA and psychiatric co-morbidity were assessed by standardised questionnaires; and 3) availability of adequate information to calculate the effect size. Random-effects models were used to calculate the aggregate prevalence and the pooled odds ratios (OR).Results: Eight studies comprising 1641 patients suffering from IA and 11210 controls were included. Our analyses demonstrated a significant and positive association between IA and alcohol abuse (OR = 3.05, 95% CI = 2.14-4.37, z = 6.12, P < 0.001), attention deficit and hyperactivity (OR = 2.85, 95% CI = 2.15-3.77, z = 7.27, P < 0.001), depression (OR = 2.77, 95% CI = 2.04-3.75, z = 6.55, P < 0.001) and anxiety (OR = 2.70, 95% CI = 1.46-4.97, z = 3.18, P = 0.001).Conclusions: IA is significantly associated with alcohol abuse, attention deficit and hyperactivity, depression and anxiety. © 2014 Ho et al.; licensee BioMed Central Ltd

    A primary current distribution model of a novel micro-electroporation channel configuration

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    Traditional macro and micro-electroporation devices utilize facing electrodes, which generate electric fields inversely proportional to their separation distance. Although the separation distances in micro-electroporation devices are significantly smaller than those in macro-electroporation devices, they are limited by cell size. Because of this, significant potential differences are required to induce electroporation. These potential differences are often large enough to cause water electrolysis, resulting in electrode depletion and bubble formation, both of which adversely affect the electroporation process. Here, we present a theoretical study of a novel micro-electroporation channel composed of an electrolyte flowing over a series of adjacent electrodes separated by infinitesimally small insulators. Application of a small, non-electrolysis inducing potential difference between the adjacent electrodes results in radially-varying electric fields that emanate from these insulators, causing cells flowing through the channel to experience a pulsed electric field. This eliminates the need for a pulse generator, making a minimal power source (such as a battery) the only electrical equipment that is needed. A non-dimensional primary current distribution model of the novel micro-electroporation channel shows that decreasing the channel height results in an exponential increase in the electric field magnitude, and that cells experience exponentially greater electric field magnitudes the closer they are to the channel walls. Finally, dimensional primary current distribution models of two potential applications, water sterilization and cell transfection, demonstrate the practical feasibility of the novel micro-electroporation channel

    Brief report: the utilization of influencing tactics for the implementation of infection control policies.

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