787 research outputs found
Molecular cytogenetic characterisation of Salix viminalis L. using repetitive DNA sequences
Abstract Salix viminalis L. (2n=38) is a diploid dicot
species belonging to the Salix genus of the Salicaceae
family. This short-rotation woody crop is one of the most
important renewable bioenergy resources worldwide. In
breeding for high biomass productivity, limited knowledge
is available on the molecular cytogenetics of willow, which
could be combined with genetic linkage mapping. The present
paper describes the adaptation of a fluorescence in situ
hybridisation (FISH) protocol as a new approach to analyse
the genomic constitution of Salix viminalis using the heterologous
DNA clones pSc119.2, pTa71, pTa794, pAs1, Afafamily,
pAl1, HT100.3, ZCF1 and the GAA microsatellite
marker. Three of the nine probes showed unambiguous
signals on the metaphase chromosomes. FISH analysis with
the pTa71 probe detected one major 18S-5.8S-26S rDNA
locus on the short arm of one chromosome pair; however,
the pTa794 rDNA site was not visible. One chromosome
pair showed a distinct signal around the centromeric
region after FISH with the telomere-specific
DNA clone HT100.3. Two chromosome pairs were
found to have pAs1 FISH signals, which represent a
D-genome-specific insert from Aegilops tauschii. Based
on the FISH study, a set of chromosomes with characteristic
patterns is presented, which could be used to
establish the karyotype of willow species
Computational design of rare-earth reduced permanent magnets
Multiscale simulation is a key research tool in the quest for new permanent magnets. Starting with first principles methods, a sequence of simulation methods can be applied to calculate the maximum possible coercive field and expected energy density product of a magnet made from a novel magnetic material composition. Iron (Fe)-rich magnetic phases suitable for permanent magnets can be found by means of adaptive genetic algorithms. The intrinsic properties computed by ab intro simulations are used as input for micromagnetic simulations of the hysteresis properties of permanent magnets with a realistic structure. Using machine learning techniques, the magnet's structure can be optimized so that the upper limits for coercivity and energy density product for a given phase can be estimated. Structure property relations of synthetic permanent magnets were computed for several candidate hard magnetic phases. The following pairs (coercive field (T), energy density product (kJ.m(-3))) were obtained for iron-tin-antimony (Fe3Sn0.75Sb0.25): (0.49, 290), L1(0) -ordered iron-nickel (L1(0) FeNi): (1, 400), cobalt-iron-tantalum (CoFe6Ta): (0.87, 425), and manganese-aluminum (MnAl): (0.53, 80).Web of Science6215314
Tuning the magnetic anisotropy of single molecules
The magnetism of single atoms and molecules is governed by the atomic scale
environment. In general, the reduced symmetry of the surrounding splits the
states and aligns the magnetic moment along certain favorable directions. Here,
we show that we can reversibly modify the magnetocrystalline anisotropy by
manipulating the environment of single iron(II) porphyrin molecules adsorbed on
Pb(111) with the tip of a scanning tunneling microscope. When we decrease the
tip--molecule distance, we first observe a small increase followed by an
exponential decrease of the axial anisotropy on the molecules. This is in
contrast to the monotonous increase observed earlier for the same molecule with
an additional axial Cl ligand. We ascribe the changes in the anisotropy of both
species to a deformation of the molecules in the presence of the attractive
force of the tip, which leads to a change in the level alignment. These
experiments demonstrate the feasibility of a precise tuning of the magnetic
anisotropy of an individual molecule by mechanical control.Comment: 16 pages, 5 figures; online at Nano Letters (2015
Note Illustrative della Carta Geologica D’Italia alla scala 1:50.000 foglio 203 Poggio Renatico
none9L’analisi del Foglio 203 Poggio Renatico è stata affrontata con l’obiettivo di ricostruire l’assetto tridimensionale dei depositi della pianura e di rappresentarlo tramite la carta geologica di superficie e le due sezioni A-A’ e B-B’ (Carta Geologica sensu stricto), la carta di sottosuolo e le sezioni geologiche C-C’, D-D’, E-E’ e F-F’ realizzate con diversi gradi di dettaglio (Foglio Allegato alla Carta Geologica - Geologia di Sottosuolo). Per questo motivo il rilevamento geologico del Foglio è stato condotto attraverso l’analisi integrata di dati di superficie e di sottosuolo e, nell’ambito della Carta Geologica d’Italia, proprio la cartografia di sottosuolo qui prodotta costituisce un elemento di novità che viene considerato dai realizzatori del Foglio un importante strumento propedeutico per le analisi geologiche delle aree di pianura. Questo lavoro è stato realizzato grazie alla disponibilità di un archivio di dati stratigrafici: la banca dati geognostici, realizzata dal Servizio Geologico, Sismico e dei Suoli della Regione Emilia-Romagna. La banca dati, inoltre, è stata arricchita di nuove prove geognostiche: sondaggi a carotaggio continuo, prove penetrometriche e trivellate manuali, eseguite ad hoc durante il rilevamento del Fogliodisponibile on line all'indirizzo: https://applicazioni.regione.emilia-romagna.it/gstatico/documenti/Note_Illustrative/NI_203rete.pdfopenCibin U.; Segadelli S.; Albertini C.; Ceriani A.; Di Giulio A.; Di Cocco I.; Colalongo M.L.; Fiorini F.; Vaiani S.C.Cibin U.; Segadelli S.; Albertini C.; Ceriani A.; Di Giulio A.; Di Cocco I.; Colalongo M.L.; Fiorini F.; Vaiani S.C
Estimating daily nitrogen dioxide level: Exploring traffic effects
Data used to assess acute health effects from air pollution typically have
good temporal but poor spatial resolution or the opposite. A modified
longitudinal model was developed that sought to improve resolution in both
domains by bringing together data from three sources to estimate daily levels
of nitrogen dioxide () at a geographic location. Monthly
measurements at 316 sites were made available by the Study of
Traffic, Air quality and Respiratory health (STAR). Four US Environmental
Protection Agency monitoring stations have hourly measurements of . Finally, the Connecticut Department of Transportation provides data on
traffic density on major roadways, a primary contributor to
pollution. Inclusion of a traffic variable improved performance of the model,
and it provides a method for estimating exposure at points that do not have
direct measurements of the outcome. This approach can be used to estimate daily
variation in levels of over a region.Comment: Published in at http://dx.doi.org/10.1214/13-AOAS642 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Visualizing intramolecular distortions as the origin of transverse magnetic anisotropy
The magnetic properties of metal–organic complexes are strongly influenced by conformational changes in the ligand. The flexibility of Fe-tetra-pyridyl-porphyrin molecules leads to different adsorption configurations on a Au(111) surface. By combining low-temperature scanning tunneling spectroscopy and atomic force microscopy, we resolve a correlation of the molecular configuration with different spin states and magnitudes of magnetic anisotropy. When the macrocycle exhibits a laterally undistorted saddle shape, the molecules lie in a S = 1 state with axial anisotropy arising from a square-planar ligand field. If the symmetry in the molecular ligand field is reduced by a lateral distortion of the molecule, we find a finite contribution of transverse anisotropy. Some of the distorted molecules lie in a S = 2 state, again exhibiting substantial transverse anisotropy
Body image perception and body composition: assessment of perception inconsistency by a new index
BACKGROUND: A correct perception of the body image, as defined by comparison with actual anthropometric analyses, is crucial to ensure the best possible nutritional status of each individual. Bioimpedance analysis (BIA) represents a leading technique to assess body composition parameters and, in particular, the fat mass. This study examined the self-perception of body image at various levels of adiposity proposing a new index. METHODS: We investigated 487 young Italian adults (mean age of males: 21.9 ± 2.4 years; mean age of females: 21.0 ± 2.2 years). Each subject could choose, on the Contour Drawing Rating Scale, the silhouette that he/she considered most resembling his/her perceived body image as well as his/her ideal body image. On each subject, we performed anthropometric measurements and determined the values of Fat mass and út with BIA. A new index, FAIFAT (Feel fat status minus Actual fat status Inconsistency), was developed to evaluate possible fat status perception inconsistencies by BIA. RESULTS: Based on ideal and feel body image comparison, women showed higher dissatisfaction than men and preferred slimmer silhouettes. FAIFAT values indicated that the fat status perception was correct in the majority of the examined individuals and only three subjects showed a serious misperception. CONCLUSIONS: Our findings suggest that FAIFAT is an appropriate index for assessing the perceived fat status from the body image when compared with data obtained by BIA. In a population, the use of this index will allow the correct identification of groups at risk for eating disorders
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Distinctive Structural and Molecular Features of Myelinated Inhibitory Axons in Human Neocortex.
Numerous types of inhibitory neurons sculpt the performance of human neocortical circuits, with each type exhibiting a constellation of subcellular phenotypic features in support of its specialized functions. Axonal myelination has been absent among the characteristics used to distinguish inhibitory neuron types; in fact, very little is known about myelinated inhibitory axons in human neocortex. Here, using array tomography to analyze samples of neurosurgically excised human neocortex, we show that inhibitory myelinated axons originate predominantly from parvalbumin-containing interneurons. Compared to myelinated excitatory axons, they have higher neurofilament and lower microtubule content, shorter nodes of Ranvier, and more myelin basic protein (MBP) in their myelin sheath. Furthermore, these inhibitory axons have more mitochondria, likely to sustain the high energy demands of parvalbumin interneurons, as well as more 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP), a protein enriched in the myelin cytoplasmic channels that are thought to facilitate the delivery of nutrients from ensheathing oligodendrocytes. Our results demonstrate that myelinated axons of parvalbumin inhibitory interneurons exhibit distinctive features that may support the specialized functions of this neuron type in human neocortical circuits
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