215 resultados para Shaker K Channel
Resumo:
The unique combination of landscapes and processes that are present and operate on Fraser Island (K'gari) create a dynamic setting that is capable of recording past environmental events, climate variations and former landscapes. Likewise, its geographic position makes Fraser Island sensitive to those events and processes. Based on optically stimulated luminescence dating, the records archived within the world's largest sand island span a period that has the potential to exceed 750 ka and contain specific records that are of extremely high resolution over the past 40,000 years. This is due to the geographic position of Fraser Island, which lies in the coastal subtropical region of Queensland Australia. Fraser Island is exposed to the open ocean currents of the Coral Sea on the east coast and the waters of Hervey Bay on its western margin and is positioned to receive moisture from the Indo-Australian monsoon, southeast trade winds and experiences occasional tropical and ex-tropical cyclones. We review literature that presents the current level of understanding of sea level change, ecological variation and environmental change on Fraser Island. The previous works illustrate the importance of Fraser Island and may link processes, environments and climates on Fraser Island with global records.
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Changes in water quality parameters such as pH and salinity can have a significant effect on productivity of aquaculture species. Similarly, relative osmotic pressure influences various physiological processes and regulates expression of a number of osmoregulatory genes. Among those, carbonic anhydrase (CA) plays a key role in systemic acid–base balance and ion regulation. Redclaw crayfish (Cherax quadricarinatus) are unique in their ability to thrive in environments with naturally varied pH levels, suggesting unique adaptation to pH stress. To date, however, no studies have focused on identification and characterisation of CA or other osmoregulatory genes in C. quadricarinatus. Here, we analysed the redclaw gill transcriptome and characterized CA genes along with a number of other key osmoregulatory genes that were identified in the transcriptome. We also examined patterns of gene expression of these CA genes when exposed to three pH treatments. In total, 72,382,710 paired end Illumina reads were assembled into 36,128 contigs with an average length of 800 bp. Approximately 37% of contigs received significant BLAST hits and 22% were assigned gene ontology terms. Three full length CA isoforms; cytoplasmic CA (ChqCAc), glycosyl-phosphatidylinositol-linked CA (ChqCAg), and β-CA (ChqCA-beta) as well as two partial CA gene sequences were identified. Both partial CA genes showed high similarity to ChqCAg and appeared to be duplicated from the ChqCAg. Full length coding sequences of Na+/K+-ATPase, V-type H+-ATPase, sarcoplasmic Ca+-ATPase, arginine kinase, calreticulin and Cl− channel protein 2 were also identified. Only the ChqCAc gene showed significant differences in expression across the three pH treatments. These data provide valuable information on the gill expressed CA genes and their expression patterns in freshwater crayfish. Overall our data suggest an important role for the ChqCAc gene in response to changes in pH and in systemic acid–base balance in freshwater crayfish.
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Light emitting field effect transistors (LEFETs) are emerging as a multi-functional class of optoelectronic devices. LEFETs can simultaneously execute light emission and the standard logic functions of a transistor in a single architecture. However, current LEFET architectures deliver either high brightness or high efficiency but not both concurrently, thus limiting their use in technological applications. Here we show an LEFET device strategy that simultaneously improves brightness and efficiency. The key step change in LEFET performance arises from the bottom gate top-contact device architecture in which the source/drain electrodes are semitransparent and the active channel contains a bi-layer comprising of a high mobility charge-transporting polymer, and a yellow-green emissive polymer. A record external quantum efficiency (EQE) of 2.1% at 1000cd/m2 is demonstrated for polymer based bilayer LEFETs.
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Hollow flange channel section is a cold-formed high-strength and thin-walled steel section with a unique shape including two rectangular hollow flanges and a slender web. Due to its mono-symmetric characteristics, it will also be subjected to torsion when subjected to transverse loads in practical applications. Past research on steel beams subject to torsion has concentrated on open sections while very few steel design standards give suitable design rules for torsion design. Since the hollow flange channel section is different from conventional open sections, its torsional behaviour remains unknown to researchers. Therefore the elastic behaviour of hollow flange channel sections subject to uniform and non-uniform torsion, and combined torsion and bending was investigated using the solutions of appropriate differential equilibrium equations. The section torsion shear flow, warping normal stress distribution, and section constants including torsion constant and warping constant were obtained. The results were compared with those from finite element analyses that verified the accuracy of analytical solutions. Parametric studies were undertaken for simply supported beams subject to a uniformly distributed torque and a uniformly distributed transverse load applied away from the shear centre. This paper presents the details of this research into the elastic behaviour and strength of hollow flange channel sections subject to torsion and bending and the results.
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The LiteSteel beam (LSB) is a cold-formed high strength steel channel section made of two torsionally rigid closed flanges and a slender web. Due to its mono-symmetric characteristics, its centroid and shear centre do not coincide. The LSBs can be used in floor systems as joists or bearers and in these applications they are often subjected to transverse loads that are applied away from the shear centre. Hence they are often subjected to combined bending and torsion actions. Previous researches on LSBs have concentrated on their bending or shear behaviour and strengths, and only limited research has been undertaken on their combined bending and torsion behaviour. Therefore in this research a series of nine experiments was first conducted on LSBs subject to combined bending and torsion. Three LSB sections were tested to failure under eccentric loading at mid-span, and appropriate results were obtained from seven tests. A special test rig was used to simulate two different eccentricities and to provide accurate simple boundary conditions at the supports. Finite element models of tested LSBs were developed using ANSYS, and the ultimate strengths, failure modes, and load–displacement curves were obtained and compared with corresponding test results. Finite element analyses agreed well with test results and hence the developed models were used in a parametric study to investigate the effects of load locations, eccentricities, and spans on the combined bending and torsion behaviour of LSBs. The interaction between the ultimate bending and torsional moment capacities was studied and a simple design rule was proposed. This paper presents the details of the tests, finite element analyses, and parametric study of LSBs subject to combined bending and torsion, and the results.
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Lipped channel beams (LCBs) are commonly used as floor joists and bearers in buildings. However, they are subjected to specific failure modes such as web crippling. Despite considerable web crippling research, recent studies [1-6] have shown that the current web crippling design rules are unable to predict the test capacities under ETF and ITF load cases. In many instances, the predictions by the available design standards such as AISI S100, AS/NZS 4600 and Eurocode 3 Part 1-3 [7-9] are inconsistent. Hence thirty-six tests were conducted to assess the web crippling behaviour and strengths of LCBs under two flange load cases. Experimental web crippling capacities were then compared with the predictions from the current design rules. These comparisons showed that AS/NZS 4600 and AISI S100 design equations are very unconservative for LCB sections under ETF load case and are conservative for ITF load case. Hence improved equations were proposed to determine the web crippling capacities of LCBs. Suitable design rules were also developed using the direct strength method. This paper presents the details of this study and the results including improved design rules.
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Our aim is to examine evidence-based strategies to motivate appropriate action and increase informed decision-making during the response and recovery phases of disasters. We combine expertise in communication, consumer psychology and marketing, disaster and emergency management, and law. This poster presents findings from a social media work package, and preliminary findings from the focus group work package on emergency warning message comprehension.
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Osteoporotic fracture is a major cause of morbidity and mortality worldwide. Low bone mineral density (BMD) is a major predisposing factor to fracture and is known to be highly heritable. Site-, gender-, and age-specific genetic effects on BMD are thought to be significant, but have largely not been considered in the design of genome-wide association studies (GWAS) of BMD to date. We report here a GWAS using a novel study design focusing on women of a specific age (postmenopausal women, age 55-85 years), with either extreme high or low hip BMD (age- and gender-adjusted BMD z-scores of +1.5 to +4.0, n = 1055, or -4.0 to -1.5, n = 900), with replication in cohorts of women drawn from the general population (n = 20,898). The study replicates 21 of 26 known BMD-associated genes. Additionally, we report suggestive association of a further six new genetic associations in or around the genes CLCN7, GALNT3, IBSP, LTBP3, RSPO3, and SOX4, with replication in two independent datasets. A novel mouse model with a loss-of-function mutation in GALNT3 is also reported, which has high bone mass, supporting the involvement of this gene in BMD determination. In addition to identifying further genes associated with BMD, this study confirms the efficiency of extreme-truncate selection designs for quantitative trait association studies. © 2011 Duncan et al.
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Automatic speech recognition from multiple distant micro- phones poses significant challenges because of noise and reverberations. The quality of speech acquisition may vary between microphones because of movements of speakers and channel distortions. This paper proposes a channel selection approach for selecting reliable channels based on selection criterion operating in the short-term modulation spectrum domain. The proposed approach quantifies the relative strength of speech from each microphone and speech obtained from beamforming modulations. The new technique is compared experimentally in the real reverb conditions in terms of perceptual evaluation of speech quality (PESQ) measures and word error rate (WER). Overall improvement in recognition rate is observed using delay-sum and superdirective beamformers compared to the case when the channel is selected randomly using circular microphone arrays.
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Osteoporosis and disorders of bone fragility are highly heritable, but despite much effort the identities of few of the genes involved has been established. Recent developments in genetics such as genome-wide association studies are revolutionizing research in this field, and it is likely that further contributions will be made through application of next-generation sequencing technologies, analysis of copy number variation polymorphisms, and high-throughput mouse mutagenesis programs. This article outlines what we know about osteoporosis genetics to date and the probable future directions of research in this field.
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Fire safety plays a vital role in building design because appropriate level of fire safety is important to safeguard lives and property. Cold-formed steel channel sections along with fire-resistive plasterboards are used to construct light-gauge steel frame (LSF) floor systems to provide adequate fire resistance ratings (FRR). It is common practice to use lipped channel sections (LCS) as joists in LSF floor systems, and past research has only considered such systems. This research focuses on adopting improved joist sections such as hollow flange channel (HFC) sections to improve the structural performance and FRR of cold-formed LSF floor systems under standard fire conditions. The structural and thermal performances of LSF floor systems made of a welded HFC, LiteSteel Beams (LSB), with different plasterboard and insulation configurations, were investigated using four full-scale fire tests under standard fires. These fire tests showed that the new LSF floor system with LSB joists improved the FRR in comparison to that of conventional LCS joists. Fire tests have provided valuable structural and thermal performance data of tested floor systems that included time-temperature profiles and failure times, temperatures, and modes. This paper presents the details of the fire tests conducted in this study and their results along with some important findings.
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Schizophrenia is an idiopathic mental disorder with a heritable component and a substantial public health impact. We conducted a multi-stage genome-wide association study (GWAS) for schizophrenia beginning with a Swedish national sample (5,001 cases and 6,243 controls) followed by meta-Analysis with previous schizophrenia GWAS (8,832 cases and 12,067 controls) and finally by replication of SNPs in 168 genomic regions in independent samples (7,413 cases, 19,762 controls and 581 parent-offspring trios). We identified 22 loci associated at genome-wide significance; 13 of these are new, and 1 was previously implicated in bipolar disorder. Examination of candidate genes at these loci suggests the involvement of neuronal calcium signaling. We estimate that 8,300 independent, mostly common SNPs (95% credible interval of 6,300-10,200 SNPs) contribute to risk for schizophrenia and that these collectively account for at least 32% of the variance in liability. Common genetic variation has an important role in the etiology of schizophrenia, and larger studies will allow more detailed understanding of this disorder.
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PURPOSE The restricted genetic diversity and homogeneous molecular basis of Mendelian disorders in isolated founder populations have rarely been explored in epilepsy research. Our long-term goal is to explore the genetic basis of epilepsies in one such population, the Gypsies. The aim of this report is the clinical and genetic characterization of a Gypsy family with a partial epilepsy syndrome. METHODS Clinical information was collected using semistructured interviews with affected subjects and informants. At least one interictal electroencephalography (EEG) recording was performed for each patient and previous data obtained from records. Neuroimaging included structural magnetic resonance imaging (MRI). Linkage and haplotype analysis was performed using the Illumina IVb Linkage Panel, supplemented with highly informative microsatellites in linked regions and Affymetrix SNP 5.0 array data. RESULTS We observed an early-onset partial epilepsy syndrome with seizure semiology strongly suggestive of temporal lobe epilepsy (TLE), with mild intellectual deficit co-occurring in a large proportion of the patients. Psychiatric morbidity was common in the extended pedigree but did not cosegregate with epilepsy. Linkage analysis definitively excluded previously reported loci, and identified a novel locus on 5q31.3-q32 with an logarithm of the odds (LOD) score of 3 corresponding to the expected maximum in this family. DISCUSSION The syndrome can be classified as familial temporal lobe epilepsy (FTLE) or possibly a new syndrome with mild intellectual deficit. The linked 5q region does not contain any ion channel-encoding genes and is thus likely to contribute new knowledge about epilepsy pathogenesis. Identification of the mutation in this family and in additional patients will define the full phenotypic spectrum.
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The fire performance of cold-formed steel members is an important criterion to be verified for their successful use in structural applications. However, lack of clear design guidance on their fire performance has inhibited their usage in buildings. Their elevated temperature mechanical properties, i.e., yield strengths, elastic moduli and stress–strain relationships, are imperative for the fire design. In the past many researchers have proposed elevated temperature mechanical property reduction factors for cold-formed steels, however, large variations exist among them. The LiteSteel Beam (LSB), a hollow flange channel section, is manufactured by a combined cold-forming and electric resistance welding process. Its web, inner and outer flange elements have different yield strengths due to varying levels of cold-working caused by their manufacturing process. Elevated temperature mechanical properties of LSBs are not the same even within their cross-sections. Therefore an experimental study was undertaken to determine the elevated temperature mechanical properties of steel plate elements in LSBs. Elevated temperature tensile tests were performed on web, inner and outer flange specimens taken from LSBs, and their results are presented in this paper including their comparisons with previous studies. Based on the test results and the proposed values from previous studies and fire design standards, suitable predictive equations are proposed for the determination of elevated temperature mechanical properties of LSB web and flange elements. Suitable stress–strain models are also proposed for the plate elements of this cold-formed and welded hollow flange channel section.
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Fire resistance of load bearing Light Gauge Steel Frame (LSF) wall systems is important to protect lives and properties in fire accidents. Recent fire tests of LSF walls made of the new cold-formed and welded hollow flange channel (HFC) section studs and the commonly used lipped channel section (LCS) studs have shown the influence of stud sections on the fire resistance rating (FRR) of LSF walls. To advance the use of HFC section studs and to verify the outcomes from the fire tests, finite element models were developed to predict the structural fire performance of LSF walls made of welded HFC section studs. The developed models incorporated the measured non-uniform temperature distributions in LSF wall studs due to the exposure of standard fire on one side, and accurate elevated temperature mechanical properties of steel used in the stud sections. These models simulated the various complexities involved such as thermal bowing and neutral axis shift caused by the non-uniform temperature distribution in the studs. The finite element analysis (FEA) results agreed well with the full scale fire test results including the FRR, outer hot and cold flange temperatures at failure and axial deformation and lateral displacement profiles. They also confirmed the superior fire performance of LSF walls made of HFC section studs. The applicability of both transient and steady state FEA of LSF walls under fire conditions was verified in this study, which also investigated the effects of using various temperature distribution patterns across the cross-section of HFC section studs on the FRR of LSF walls. This paper presents the details of this numerical study and the results.