Improved knowledge of genome composition, especially of its repetitive component, generates important informations in both theoretical and applied research. In this study, we provide the first ...insight into the local organization of the sunflower genome by sequencing and annotating 349,380 bp from 3 BAC clones, each including one single-copy gene. These analyses resulted in the identification of 11 putative gene sequences, 18 full-length LTR retrotransposons, 6 incomplete LTR retrotransposons, 2 non-autonomous LTR-retroelements (LINEs), 2 putative DNA transposons fragments and one putative helitron. Among LTR-retrotransposons, non-autonomous elements (the so-called LARDs), which do not carry any protein-encoding sequence, were discovered for the first time in the sunflower. The insertion time of intact retroelements was measured, based on sister LTRs divergence. All isolated elements were inserted relatively recently, especially those belonging to the Gypsy superfamily. Retrotransposon families related to those identified in the BAC clones are present also in other species of Helianthus, both annual and perennial, and even in other Asteraceae. In one of the three BAC clones, we found five copies of a lipid transfer protein (LTP) encoding gene within less than 100,000 bp, four of which are potentially functional. Two of these are interrupted by LTR retrotransposons, in the intron and in the coding sequence, respectively. The divergence between sister LTRs of the retrotransposons inserted within the genes indicates that LTP gene duplication started earlier than 1.749 MYRS ago. On the whole, the results reported in this study confirm that the sunflower is an excellent system to study transposons dynamics and evolution.
A new technique for partial discharge (PD) source location in cable systems is presented in this paper. Such technique, here referred to as amplitude-frequency (AF) mapping, is based on the influence ...of attenuation and dispersion phenomena on PD pulse time and frequency characteristics. A comparative evaluation with other two well-known location techniques, i.e., time-domain reflectometry (TDR) and arrival time analysis (ATA) is presented through working cases. The results indicate that while TDR is appropriate for short cable systems, for longer cable systems, location by AF mapping can be obtained directly from PD testing, without additional efforts. The location thus achieved is, in most cases, accurate enough to allow maintenance practices to be carried out effectively. In some cases, ATA can be necessary to refine location and resolve ambiguities.
Benign familial neonatal convulsion (BFNC) is a rare autosomal dominant disorder caused by mutations in two genes, KCNQ2 and KCNQ3, encoding for potassium channel subunits underlying the M-current. ...This current limits neuronal hyperexcitability by causing spike-frequency adaptation.
The authors describe a BFNC family with four affected members: two of them exhibit BFNC only while the other two, in addition to BFNC, present either with a severe epileptic encephalopathy or with focal seizures and mental retardation.
All affected members of this family carry a novel missense mutation in the KCNQ2 gene (K526N), disrupting the tri-dimensional conformation of a C-terminal region of the channel subunit involved in accessory protein binding. When heterologously expressed in CHO cells, potassium channels containing mutant subunits in homomeric or heteromeric configuration with wild-type KCNQ2 and KCNQ3 subunits exhibit an altered voltage-dependence of activation, without changes in intracellular trafficking and plasma membrane expression.
The KCNQ2 K526N mutation may affect M-channel function by disrupting the complex biochemical signaling involving KCNQ2 C-terminus. Genetic rather than acquired factors may be involved in the pathophysiology of the phenotypic variability of the neurologic symptoms associated with BFNC in the described family.
In order to improve partial discharge (PD) detection and location in extruded power cables, Ultra-Wide Bandwidth detectors (UWB) can be preferred to wide- and narrowband systems. As UWB systems aim ...to get the broadest frequency content in PD pulses, it is important to evaluate the frequency attenuation as a function of distance propagated of the cable under test, trying to achieve optimum signal-to-noise ratio (SNR) and large detection sensitivity. Some conventional techniques able to calculate attenuation and dispersion of PD pulses are considered and a fast approximate model is developed in this paper, trying to provide a simple tool to estimate the maximum PD detection length in polymeric cable, in relation to bandwidth measurement system and required sensitivity.
Tonelli A, Romaniello R, Grasso R, Cavallini A, Righini A, Bresolin N, Borgatti R, Bassi MT. Novel splice‐site mutations and a large intragenic deletion in PLA2G6 associated with a severe and rapidly ...progressive form of infantile neuroaxonal dystrophy.
Infantile neuroaxonal dystrophy, INAD, is a severe progressive psychomotor disorder with infantile onset and characterized by the presence of axonal spheroids throughout the central and peripheral nervous systems. A subset of INAD patients shows also brain iron accumulation which represents instead the distinctive feature of the idiopathic neurodegeneration with brain iron accumulation, NBIA. These diseases share the same causative gene, PLA2G6, encoding iPLA2‐VIA, a calcium‐independent phospholipase. Mutations that lead to a complete absence of protein are associated with a severe INAD profile, while compound heterozygous mutations with possibly a residual protein activity are instead associated with the less severe NBIA phenotype. Here we describe two INAD patients both with an unusually rapid disease progression and a peculiar neuroradiological presentation in one of them. Compound heterozygosity for a large intragenic deletion and a nonsense mutation was found in one of them while the other is carrying two novel splice‐site mutations. Breakpoint‐sequence analysis suggests a non‐allelic‐homologous‐recombination (NAHR) event, probably underlying the rearrangement. These findings, while supporting the genotype–phenotype correlation already observed in INAD patients, provide the first sequence characterization of a genomic rearrangement in PLA2G6 gene, thus orienting the search for missing mutant alleles in PLA2G6 related diseases.
This paper reports experimental heat transfer coefficients and pressure drops measured during condensation inside a smooth tube when operating with pure HFC refrigerants (R134a, R125, R236ea, R32) ...and the nearly azeotropic HFC refrigerant blend R410A. Data taken when condensing HCFC-22 are also reported for reference. The experimental runs are carried out at a saturation temperature ranging between 30 and 50°C, and mass velocities varying from 100 to 750 kg/(m
2 s), over the vapour quality range 0.15–0.85. The effects of vapour quality, mass velocity, saturation temperature and temperature difference between saturation and tube wall on the heat transfer coefficient are investigated by analysing the experimental data. A predictive study of the condensation flow patterns occurring during the tests is also presented. Finally comparisons with predictions from the model by
Kosky and Staub (Kosky PG, Staub FW. Local condensing heat transfer coefficients in the annular flow regime. AIChE J 1971;17:1037) are reported for all the data sets.
Cette communication décrit les coefficients de transfert de chaleur et les chutes de pression mesurées lors de la condensation à l'intérieur d'un tube lisse lorsqu'on utilise des frigorigènes HFC purs (le R134a, le R125, le R236ea et le R32) et le R410A, un mélange HFC quasi azéotropique. On fournit des données obtenues lors de la condensation de HCFC-22 afin de servir de référence. Les essais ont été effectués à une température de saturation allant de 30 à 50°C, pour des débits massiques dans un éventail de 100 à 750 kg/(m
2.s) pour une gamme de qualité de vapeur de 0,15 à 0,85. A l'aide de l'analyse des données expérimentales, les auteurs ont étudié les effets de la qualité de la vapeur, le débit massique, la température de saturation et la différence de température entre la température de saturation et la température de la paroi sur le coefficient de transfert de chaleur. On présente également une étude prévisonnelle de l'écoulement lors de la condensation. Enfin, les auteurs effectuent des comparaisons avec les prévisions du modèle de Kosky et Staub (Kosky PG, Staub FW. Local condensing heat transfer coefficients in the annular flow regime. AIChE 1971;1037) pour toutes les données obtenues.
Organic semiconducting molecules are receiving a large attention because of their potential applications, spanning from OLEDs to plastic photovoltaics to bio-chemical sensors. However, the electronic ...transport properties of these materials are still not fully understood, and organic single crystals (OSCs) may represent model materials for assessing the charge transport mechanisms, thanks to their high purity and molecular order. Here we show for the first time that solution-grown, millimiter-sized organic single crystals of 4-hydroxycyanobenzene (4HCB) possess a clear and reproducible three-dimensional anisotropy in their main transport parameters: (i) charge carrier mobility, (ii) distribution of the electronic density of states and (iii) deep traps energy and concentration, and we report intrinsic-like three-dimensional mobility values for these crystals. These findings demonstrate that the electronic spatial anisotropy of OSCs extends well beyond the carrier mobility, and open the way to the development of novel electronic device architectures based on the simultaneous exploitation of different electronic responses along the three spatial directions of the crystal.
This paper presents a critical review of correlations to compute heat transfer coefficients and pressure drop, for refrigerants condensing inside commercially available tubes with enhanced surfaces ...of various types, and a theoretical analysis of the condensation phenomenon. Predictions from some of the above equations are compared with experimental data. In addition, information is presented about the influence of small amounts of compressor oil on the condensation of refrigerants in enhanced tubes.
Cet article expose une analyse critique des corrélations utilisées pour calculer les transferts de chaleur et les chutes de pression lors de la condensation des frigorigènes à l'intérieur de divers types de tubes horizontaux à surface augmentée. Une analyse théorique du phénomène de condensation est également effectuée. Les prévisions fondées sur les équations utilisées sont comparées aux données obtenues de façon expérimentale. En outre, les auteurs fournissent les informations sur l'influence de petites quantités d'huile en provenance du compresseur sur la condensation des frigorigènes dans les tubes à surface augmentée.
We report on our multi–pronged approach to understand the structural and electrical properties of an InAl(Ga)N(33nm barrier)/Al(Ga)N(1nm interlayer)/GaN(3μm)/ AlN(100nm)/Al2O3 high electron mobility ...transistor (HEMT) heterostructure grown by metal organic vapor phase epitaxy (MOVPE). In particular we reveal and discuss the role of unintentional Ga incorporation in the barrier and also in the interlayer. The observation of unintentional Ga incorporation by using energy dispersive X–ray spectroscopy analysis in a scanning transmission electron microscope is supported with results obtained for samples with a range of AlN interlayer thicknesses grown under both the showerhead as well as the horizontal type MOVPE reactors. Poisson–Schrödinger simulations show that for high Ga incorporation in the Al(Ga)N interlayer, an additional triangular well with very small depth may be exhibited in parallel to the main 2–DEG channel. The presence of this additional channel may cause parasitic conduction and severe issues in device characteristics and processing. Producing a HEMT structure with InAlGaN as the barrier and AlGaN as the interlayer with appropriate alloy composition may be a possible route to optimization, as it might be difficult to avoid Ga incorporation while continuously depositing the layers using the MOVPE growth method. Our present work shows the necessity of a multicharacterization approach to correlate structural and electrical properties to understand device structures and their performance.
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