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Two new haemoglobin variants involving proline substitutions 总被引:1,自引:0,他引:1
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This paper estimates a forecasting equation for the hourly peak electricity demand one day in the future. The models incorporate deterministic influences such as holidays, stochastic influences such as average loads by building bivariate models, and exogenous influences such as the weather which is given a careful non-linear formulation. Out-of-sample comparisons are made using an additional year of data. 相似文献
4.
Mutation of TDP1, encoding a topoisomerase I-dependent DNA damage repair enzyme,in spinocerebellar ataxia with axonal neuropathy 总被引:14,自引:0,他引:14
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Taxadiene synthase structure and evolution of modular architecture in terpene biosynthesis 总被引:1,自引:0,他引:1
With more than 55,000 members identified so far in all forms of life, the family of terpene or terpenoid natural products represents the epitome of molecular biodiversity. A well-known and important member of this family is the polycyclic diterpenoid Taxol (paclitaxel), which promotes tubulin polymerization and shows remarkable efficacy in cancer chemotherapy. The first committed step of Taxol biosynthesis in the Pacific yew (Taxus brevifolia) is the cyclization of the linear isoprenoid substrate geranylgeranyl diphosphate (GGPP) to form taxa-4(5),11(12)diene, which is catalysed by taxadiene synthase. The full-length form of this diterpene cyclase contains 862 residues, but a roughly 80-residue amino-terminal transit sequence is cleaved on maturation in plastids. We now report the X-ray crystal structure of a truncation variant lacking the transit sequence and an additional 27 residues at the N terminus, hereafter designated TXS. Specifically, we have determined structures of TXS complexed with 13-aza-13,14-dihydrocopalyl diphosphate (1.82?? resolution) and 2-fluorogeranylgeranyl diphosphate (2.25?? resolution). The TXS structure reveals a modular assembly of three α-helical domains. The carboxy-terminal catalytic domain is a class?I terpenoid cyclase, which binds and activates substrate GGPP with a three-metal ion cluster. The N-terminal domain and a third 'insertion' domain together adopt the fold of a vestigial class?II terpenoid cyclase. A class?II cyclase activates the isoprenoid substrate by protonation instead of ionization, and the TXS structure reveals a definitive connection between the two distinct cyclase classes in the evolution of terpenoid biosynthesis. 相似文献
6.
Yiannis Laouris Marios Michaelides Mustafa Damdelen Romina Laouri Derya Beyatli Aleco Christakis 《Systemic Practice and Action Research》2009,22(1):45-75
This paper reports the results of the first of a series of co-laboratories organized by Cypriot peace pioneers 30 months after
the negative outcome of the referendum concerning UN General Secretary’s plan for reunification of the island. The purpose
of this co-laboratory was to support a diverse group of disengaged and disappointed peace pioneers and activists representing
Turkish and Greek communities of Cyprus develop a shared understanding of factors contributing to the perceived widening of
the gap between the two divided communities in Cyprus. The co-laboratory was organized using the structured dialogic design
process (SDDP) approach within the context of a rich web-based communication environment. The root causes contributing to
the widening of the gap are discussed and are also compared with those identified during a similar co-laboratory employing
the Interactive Management methodology 12 years earlier.
相似文献
Aleco ChristakisEmail: |
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Structural, thermal, and mechanical properties of pure blend and nanocomposites based on polyurethane (PU)
and polyvinyl chloride (PVC) doped with low different content of single walled-carbon nanotubes (SWCNTs)
were studied. The nanocomposites at different concentration were prepared via casting technique. The
interaction between PU/PVC and CNTs were examined via FT-IR studies. The changes in the structures of
the nanocomposites were examined using X- Ray Diffraction (XRD), and the results indicated that the
amorphous domains of nanocomposites increased with increasing SWCNTs content. Transmission electron
microscope (TEM) observation indicated that SWCNTs surface was wrapped with the polymer with the thermal
properties of nanocomposites improved. The mechanical behavior of the nanocomposites was evaluated as a
function of SWCNTs content. The main enhancement in tensile properties was observed, e.g., the tensile
strength and elastic modulus increased compared with the pure blend, which may be attributed to the
interaction and adhesion between CNTs and the polymer matrices due to the hydrogen bonding between
carbonyl groups (C=O) of polymer blend chains and carboxylic acid (COOH) groups of CNTs. 相似文献
8.
Yiannis Laouris Ali Erel Marios Michaelides Mustafa Damdelen Tatjana Taraszow Ilke Dagli Romina Laouri Aleco Christakis 《Systemic Practice and Action Research》2009,22(5):361-381
This paper summarizes results of a co-laboratory that took place 33 months after the negative outcome of the referendum on
the UN’s proposal for the solution of the Cyprus problem, and which was a follow-up (3 months later) of a previous co-laboratory.
The earlier co-laboratory explored factors contributing to the increasing gap between the two conflicting communities. The
co-laboratory reported here engaged relevant stakeholders (peace pioneers, academics, business people, activists and others
representing the Turkish and Greek speaking communities of Cyprus) to come up with options aiming to enhance the social dialogue
between the two communities. The Structured Dialogic Design Process was used to structure 27 proposed options and develop
an influence map. The deep drivers, i.e., most influential factors, determined decisions taken by the participating peace
pioneers regarding their future interventions. The results are also discussed within the framework of current (analysis reflects
the political situation during the period reported here) political developments. 相似文献
9.
PT Tsai C Hull Y Chu E Greene-Colozzi AR Sadowski JM Leech J Steinberg JN Crawley WG Regehr M Sahin 《Nature》2012,488(7413):647-651
Autism spectrum disorders (ASDs) are highly prevalent neurodevelopmental disorders, but the underlying pathogenesis remains poorly understood. Recent studies have implicated the cerebellum in these disorders, with post-mortem studies in ASD patients showing cerebellar Purkinje cell (PC) loss, and isolated cerebellar injury has been associated with a higher incidence of ASDs. However, the extent of cerebellar contribution to the pathogenesis of ASDs remains unclear. Tuberous sclerosis complex (TSC) is a genetic disorder with high rates of comorbid ASDs that result from mutation of either TSC1 or TSC2, whose protein products dimerize and negatively regulate mammalian target of rapamycin (mTOR) signalling. TSC is an intriguing model to investigate the cerebellar contribution to the underlying pathogenesis of ASDs, as recent studies in TSC patients demonstrate cerebellar pathology and correlate cerebellar pathology with increased ASD symptomatology. Functional imaging also shows that TSC patients with ASDs display hypermetabolism in deep cerebellar structures, compared to TSC patients without ASDs. However, the roles of Tsc1 and the sequelae of Tsc1 dysfunction in the cerebellum have not been investigated so far. Here we show that both heterozygous and homozygous loss of Tsc1 in mouse cerebellar PCs results in autistic-like behaviours, including abnormal social interaction, repetitive behaviour and vocalizations, in addition to decreased PC excitability. Treatment of mutant mice with the mTOR inhibitor, rapamycin, prevented the pathological and behavioural deficits. These findings demonstrate new roles for Tsc1 in PC function and define a molecular basis for a cerebellar contribution to cognitive disorders such as autism. 相似文献
10.
近二十年来,对曲线和曲面的细分方法(Subdivision)的研究和应用在计算机图形学和造型领域中相当流行,然而对于实体的细分方法却研究得较少.在本文中,我们设计了一种基于六面体的逼近细分格式在张量积网格上表现为张量积格式,在体网格上生成光滑的极限实体,并能在实体上引入边界和折痕.根据已有的在简单六面体网格上的基于六面体的逼近格式,如果不采用一些特殊规则,设计者很难得到实体模型.我们设计了一套针对实体模型的细分规则来简化细分过程.大体上,我们的细分过程结合了简单线性细分和二层平均,对网格的局部拓扑结构没有严格要求.特别地,我们的格式可以不加修改地应用到非流形拓扑网格上.同时,我们引入了用于控制模型形状的自由参数,使模型设计更具弹性. 相似文献