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We have evaluated codon usage bias in Drosophila histone genes and have
obtained the nucleotide sequence of a 5,161-bp D. hydei histone gene repeat
unit. This repeat contains genes for all five histone proteins (H1, H2a,
H2b, H3, and H4) and differs from the previously reported one by a second
EcoRI site. These D. hydei repeats have been aligned to each other and to
the 5.0-kb (i.e., long) and 4.8-kb (i.e., short) histone repeat types from
D. melanogaster. In each species, base composition at synonymous sites is
similar to the average genomic composition and approaches that in the small
intergenic spacers of the histone gene repeats. Accumulation of synonymous
changes at synonymous sites after the species diverged is quite high. Both
of these features are consistent with the relatively low codon usage bias
observed in these genes when compared with other Drosophila genes. Thus,
the generalization that abundantly expressed genes in Drosophila have high
codon bias and low rates of silent substitution does not hold for the
histone genes.
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An Caris Cathy Macharis Gerrit K. Janssens 《Flexible Services and Manufacturing Journal》2012,24(3):294-319
In this paper the design of the service network in intermodal barge transport is studied. The network of inland barge terminals is modelled to demonstrate potential cooperations in a corridor network. Cooperation between inland terminals leads to bundling of freight flows in the hinterland of major ports. A service network design model for intermodal barge transport is developed and applied to the hinterland network of the port of Antwerp in Belgium. Selected cooperation schemes are simulated by means of a discrete event simulation model for intermodal barge transport and compared with simulation results of bundling in the port area. Cooperation between inland terminals offers an opportunity to attain economies of scale, but may not be perceived as a sole solution for reducing waiting times of inland barges at sea terminals. A combination of bundling measures in the port area and in the hinterland may be necessary to improve the intermodal transport chain. 相似文献
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Martine Mostert An Caris Sabine Limbourg 《Flexible Services and Manufacturing Journal》2018,30(3):397-420
Freight transport planning is nowadays encouraged to align with environmental objectives. Among those, climate change is of particular interest for many countries. In its White Paper on Transport, the European Commission considers intermodal transport as a potential solution for reducing environmental impacts. In order to make good strategic transport decisions, realistic decision support models for freight transport networks must be developed, so that insights can be derived for the different stakeholders of the transportation chain. This research proposes a bi-objective mathematical formulation which takes into account economic and environmental objectives, on a road and intermodal network with three modes of transport (road, intermodal rail, and intermodal inland waterways), and in which economies of scale of intermodal transport can be considered. With this model better fitting reality, an application to the Belgian case study provides practical information on how flows, terminal types and locations vary depending on the chosen policy, on the integration or not of economies of scale, on costs or emissions modifications and on the number of terminals to locate. Results show that the chosen policy influences the terminal type and the intermodal market share. The study also highlights the interest of intermodal transport on short distances, and the risk of flow exchanges inside the intermodal market share, rather than between road and intermodal transport. 相似文献
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Albumin affinity tags increase peptide half-life in vivo 总被引:1,自引:0,他引:1
Koehler MF Zobel K Beresini MH Caris LD Combs D Paasch BD Lazarus RA 《Bioorganic & medicinal chemistry letters》2002,12(20):2883-2886
Small organic molecules that bind tightly to serum albumin were applied to the amino terminus of an anticoagulant peptide in an effort to increase its protein binding in vivo. The tagged peptides were evaluated for their ability to be retained on liquid chromatographic columns with serum albumins incorporated into the stationary phase. Those which demonstrated significant affinity were administered intravenously to rabbits and found to have significantly increased plasma half-lives. Novel affinity tags were identified by appending a focused library of compounds to a model tetrapeptide and evaluating the resulting compounds' ability to bind to the serum albumin columns. The most promising were synthesized as the full length peptides and again evaluated in vivo. They were found to have still longer half-lives than the first generation compounds. 相似文献
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There is a need for safe medications that can effectively support recovery by treating symptoms of protracted abstinence that may precipitate relapse in alcoholics, e.g. craving and disturbances in sleep and mood. This proof-of-concept study reports on the effectiveness of gabapentin 1200 mg for attenuating these symptoms in a non-treatment-seeking sample of cue-reactive, alcohol-dependent individuals. Subjects were 33 paid volunteers with current Diagnostic and Statistical Manual of Mental Disorders-IV alcohol dependence and a strength of craving rating 1 SD or greater for alcohol than water cues. Subjects were randomly assigned to gabapentin or placebo for 1 week and then participated in a within-subjects trial where each was exposed to standardized sets of pleasant, neutral and unpleasant visual stimuli followed by alcohol or water cues. Gabapentin was associated with significantly greater reductions than placebo on several measures of subjective craving for alcohol as well as for affectively evoked craving. Gabapentin was also associated with significant improvement on several measures of sleep quality. Side effects were minimal, and gabapentin effects were not found to resemble any major classes of abused drugs. Results suggest that gabapentin may be effective for treating the protracted abstinence phase in alcohol dependence and that a randomized clinical trial would be an appropriate next step. The study also suggests the value of cue-reactivity studies as proof-of-concept screens for potential antirelapse drugs. 相似文献
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DANUTA WASSERMAN TRAN THI HOUNG THANH PHAM THI DUC MINH MAX GOLDSTEIN ANA NORDENSKIÖLD CAMILLA WASSERMAN 《World psychiatry》2008,7(1):47-53
The study aimed to explore the suicidal process, suicidal communication and psychosocial situation of young suicide attempters in a rural community in Hanoi, Vietnam. Semi-structured interviews were conducted, in a community setting, with 19 suicide attempters aged 15-24 who had been consecutively hospitalized in an intensive care unit. In 12 of 19 cases, the first pressing, distinct and constant suicidal thoughts appeared less than one day before the suicide attempt in question. However, distress and mild, fleeting suicidal thoughts had been present up to six months before the suicide attempt in 16 cases. Five respondents had a suicide plan one to three days before attempting suicide. Altogether, 13 engaged in some form of suicidal communication before their attempt. This communication was, however, difficult for outsiders to interpret. Twelve of the respondents were victims of regular physical abuse and 16 had suffered psychological violence for at least one year before attempting suicide. Eighteen of the respondents used pesticides or raticides in their suicide attempts. None sought advice or consultation in the community despite long-standing psychosocial problems. The strategy of reducing the availability of suicide means (e.g., pesticides or raticides) in Asian countries should be complemented with a long-term suicide-preventive strategy that targets school dropouts and domestic violence, and promotes coping abilities and communication about psychological and social problems as well as recognition of signs of distress and suicidal communication. 相似文献
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P. Caris E. Smets K. De Coster L. P. Ronse De Craene 《Plant Systematics and Evolution》2006,257(3-4):223-232
The floral ontogeny of the Spurge olive (Cneorum tricoccon L.) is studied by means of scanning electron microscopic observations. Special attention is paid to the sequence of initiation
of the floral parts, the occurrence of septal cavities, and the development of the nectariferous tissue. The nectary disc
arises as a receptacular outgrowth below the ovary and independently from stamen development. By the extensive growth of this
voluminous androgynophore, stamen filaments become enclosed by nectary tissue and as a result, they are seated in pits between
the lobes of the disc. Between ovary and style, three lobes are present, which are covered with stomata – their function is
unknown. The significance of the unusual trimery of the flower is discussed. Floral developmental evidence supports a Rutalean
affinity, although more ontogenetic investigations are needed in Rutaceae, subfamily Spathelioideae. 相似文献
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A recently silenced, duplicate PgiC locus in Clarkia 总被引:1,自引:0,他引:1
Previous electrophoretic analysis showed that 17 diploid species of the
wildflower Clarkia (Onagraceae) have two cytosolic isozymes of
phosphoglucose isomerase (PGIC; EC 5.3.1.9), whereas 15 other diploid
species have a single PGIC. Molecular studies revealed that the two
isozymes in the former species are encoded by duplicate genes, PgiC1 and
PgiC2, whereas the single isozyme in the latter is always encoded by PgiC1.
Phylogenetic analysis of the nucleotide sequences implied that PgiC2 was
silenced four times independently in the genus. Here we describe a psi
PgiC2 from C. mildrediae, a species in which only PgiC1 is expressed. The
discovery of the psi PgiC2 is significant because it confirms a formal
prediction of the phylogenetic analysis. The psi PgiC2 includes 5,039
nucleotides corresponding to 18 of the 23 exons of PgiC, as well as the
intervening introns and 3' nontranslated region. The absence of an increase
of nucleotide substitutions in its "exons" suggests that the gene was
silenced recently. The present study appears to be the first to establish
that a specific duplicate gene locus regularly expressed in a group of
related plant species has been silenced in one of them. The multiple
independent silencings of PgiC2 suggest that it remained functional but
inessential in ancestral lineages. We discuss the possibility that PgiC2
may have been preserved in these lineages by selection against mutants
causing defective PGIC1- PGIC2 heterodimers.
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