1,263 research outputs found
Identification of differentially expressed genes in seeds of two Brassica napus mutant lines with different oleic acid content
The regulation of seed oleic acid synthesis in rapeseed is largely unknown. In this study, gene expression pattern during seed development between two Brassica napus mutants was compared. Using immature seeds 27 days after pollination, differentially expressed cDNA clones were identified bysubtractive suppression hybridization (SSH). A total of 480 cDNA clones corresponding to 88 genes were found up-regulated and 18 genes down-regulated in seeds with high oleic acid content. Most ofthe differentially expressed genes are related to metabolism and regulation. The possible role of these genes in seeds was discussed. Further analysis of the function of these genes may provide novel targets for manipulation of fatty acid composition in rapeseed
On R-duals and the duality principle in Gabor analysis
The concept of R-duals of a frame was introduced by Casazza, Kutyniok and
Lammers in 2004, with the motivation to obtain a general version of the duality
principle in Gabor analysis. For tight Gabor frames and Gabor Riesz bases the
three authors were actually able to show that the duality principle is a
special case of general results for R-duals. In this paper we introduce various
alternative R-duals, with focus on what we call R-duals of type II and III. We
show how they are related and provide characterizations of the R-duals of type
II and III. In particular, we prove that for tight frames these classes
coincide with the R-duals by Casazza et el., which is desirable in the sense
that the motivating case of tight Gabor frames already is well covered by these
R-duals. On the other hand, all the introduced types of R-duals generalize the
duality principle for larger classes of Gabor frames than just the tight frames
and the Riesz bases; in particular, the R-duals of type III cover the duality
principle for all Gabor frames
Unusual conservation of mitochondrial gene order in Crassostrea oysters: evidence for recent speciation in Asia
<p>Abstract</p> <p>Background</p> <p>Oysters are morphologically plastic and hence difficult subjects for taxonomic and evolutionary studies. It is long been suspected, based on the extraordinary species diversity observed, that Asia Pacific is the epicenter of oyster speciation. To understand the species diversity and its evolutionary history, we collected five <it>Crassostrea </it>species from Asia and sequenced their complete mitochondrial (mt) genomes in addition to two newly released Asian oysters (<it>C. iredalei </it>and <it>Saccostrea mordax</it>) for a comprehensive analysis.</p> <p>Results</p> <p>The six Asian <it>Crassostrea </it>mt genomes ranged from 18,226 to 22,446 bp in size, and all coded for 39 genes (12 proteins, 2 rRNAs and 25 tRNAs) on the same strand. Their genomes contained a split of the <it>rrnL </it>gene and duplication of <it>trnM</it>, <it>trnK </it>and <it>trnQ </it>genes. They shared the same gene order that differed from an Atlantic sister species by as many as nine tRNA changes (6 transpositions and 3 duplications) and even differed significantly from <it>S. mordax </it>in protein-coding genes. Phylogenetic analysis indicates that the six Asian <it>Crassostrea </it>species emerged between 3 and 43 Myr ago, while the Atlantic species evolved 83 Myr ago.</p> <p>Conclusions</p> <p>The complete conservation of gene order in the six Asian <it>Crassostrea </it>species over 43 Myr is highly unusual given the remarkable rate of rearrangements in their sister species and other bivalves. It provides strong evidence for the recent speciation of the six <it>Crassostrea </it>species in Asia. It further indicates that changes in mt gene order may not be strictly a function of time but subject to other constraints that are presently not well understood.</p
Initial potential effect on the dissociative adsorption of methanol on a roughened platinum electrode in acidic solution
In situ Raman spectroscopic and voltammetric studies indicate that dissociative adsorption of methanol on the rough platinum electrode occurs in the hydrogen ad/desorption potential range, and the dissociative extent depends on the initial potential of the electrode before contacting methanol, in addition to the contacting time. As the dissociative product, carbon monoxide competes the site of strongly bound hydrogen preferentially, and shifts the ad/desorption potentials of weakly bound hydrogen towards more positive ones gradually with the increase of CO coverage. Whereas, formaldehyde dissociates more easily by far and completely suppresses H-adsorption. The confocal Raman spectroscopy developed on transition metals shows some intriguing advantages in investigating electrocatalytic oxidation of small organic molecules
Multiple periodic solutions for a class of second-order neutral functional differential equations
An Irish perspective on Cryptosporidium. Part 1
Cryptosporidiosis, a protozoal disease which causes significant morbidity in humans, is one of the chief causes of diarrhoea in neonatal ruminants. Although the parasite poses a significant threat to public health and animal health in Ireland, its epidemiology on the island is only poorly understood. Environmental studies have shown the waterborne parasite to be widespread in some untreated waterbodies around Ireland. The island's hydrogeological situation, combined with high stocking rates of livestock and the absence of filtration from regular water treatment, render it vulnerable to large-scale outbreaks. This review discusses the parasite in the Irish context and underlines the need for a reference facility to provide active surveillance on the island
5-Hydroxymethylfurfural (HMF) formation during subcritical water extraction
The aim of this study was to investigate the
effect of material type (artichoke leave, lemon peel, flaxseed meal), extraction temperature (50, 100, 120, 140, 160,
180, 200 C) and static extraction time (5, 15, 30, 45 min)
on 5-hydroxymethylfurfural (5-HMF) formation during
subcritical water extraction. 5-HMF content of artichoke
leave and lemon peel extracts increased 7.2 and 26.1 times
with the rise of extraction temperature from 160 to 180 C
for 5 min during subcritical water extraction, respectively.
Besides, 5-HMF content of artichoke leave, lemon peel and
flaxseed meal extracts increased 1.4, 2.0 and 4.5 times as
static extraction time increased from 15 to 45 min at
180 C during subcritical water extraction, respectively.
The highest 5-HMF content of artichoke leave and lemon
peel extracts were obtained as 58.83 and 231.21 mg/L at
180 C and 45 min, respectively. However, for flaxseed
meal, the highest 5-HMF content (222.94 mg/L) was
obtained at 200 C and 15 min during subcritical water
extraction.Project Nos. 2014.M80.02.03, 2014.M80.02.04 by Artvin Coruh University Scientific Research Project Uni
Optimal Estimation of Ion-Channel Kinetics from Macroscopic Currents
Markov modeling provides an effective approach for modeling ion channel kinetics. There are several search algorithms for global fitting of macroscopic or single-channel currents across different experimental conditions. Here we present a particle swarm optimization(PSO)-based approach which, when used in combination with golden section search (GSS), can fit macroscopic voltage responses with a high degree of accuracy (errors within 1%) and reasonable amount of calculation time (less than 10 hours for 20 free parameters) on a desktop computer. We also describe a method for initial value estimation of the model parameters, which appears to favor identification of global optimum and can further reduce the computational cost. The PSO-GSS algorithm is applicable for kinetic models of arbitrary topology and size and compatible with common stimulation protocols, which provides a convenient approach for establishing kinetic models at the macroscopic level
Review of risk factors for human echinococcosis prevalence on the Qinghai-Tibet Plateau, China: a prospective for control options
Objective: Echinococcosis is a major parasitic zoonosis of public health importance in western China. In 2004, the Chinese Ministry of Health estimated that 380,000 people had the disease in the region. The Qinghai-Tibet Plateau is highly co-endemic with both alveolar echinococcosis (AE) and cystic echinococcosis (CE). In the past years, the Chinese government has been increasing the financial support to control the diseases in this region. Therefore, it is very important to identify the significant risk factors of the diseases by reviewing studies done in the region in the past decade to help policymakers design appropriate control strategies. Review: Selection criteria for which literature to review were firstly defined. Medline, CNKI (China National Knowledge Infrastructure), and Google Scholar were systematically searched for literature published between January 2000 and July 2011. Significant risk factors found by single factor and/or multiple factors analysis were listed, counted, and summarized. Literature was examined to check the comparability of the data; age and sex specific prevalence with same data structures were merged and used for further analysis. A variety of assumed social, economical, behavioral, and ecological risk factors were studied on the Plateau. Those most at risk were Tibetan herdsmen, the old and female in particular. By analyzing merged comparable data, it was found that females had a significant higher prevalence, and a positive linearity relationship existed between echinococcosis prevalence and increasing age. In terms of behavioral risk factors, playing with dogs was mostly correlated with CE and/or AE prevalence. In terms of hygiene, employing ground water as the drinking water source was significantly correlated with CE and AE prevalence. For definitive hosts, dog related factors were most frequently identified with prevalence of CE or/and AE; fox was a potential risk factor for AE prevalence only. Overgrazing and deforestation were significant for AE prevalence only. Conclusion: Tibetan herdsmen communities were at the highest risk of echinococcosis prevalence and should be the focus of echinococcosis control. Deworming both owned and stray dogs should be a major measure for controlling echinococcosis; treatment of wild definitive hosts should also be considered for AE endemic areas. Health education activities should be in concert with the local people's education backgrounds and languages in order to be able to improve behaviors. Further researches are needed to clarify the importance of wild hosts for AE/CE prevalence, the extent and range of the impacts of ecologic changes (overgrazing and deforestation) on the AE prevalence, and risk factors in Tibet
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