3 research outputs found
From logical forms to SPARQL query with GETARUNS
We present a system for Question Answering which computes a
prospective answer from Logical Forms produced by a full-fledged NLP for
text understanding, and then maps the result onto schemata in SPARQL to be
used for accessing the Semantic Web. As an intermediate step, and whenever
there are complex concepts to be mapped, the system looks for a corresponding
amalgam in YAGO classes. It is just by the internal structure of the Logical
Form that we are able to produce a suitable and meaningful context for concept
disambiguation. Logical Forms are the final output of a complex system for text
understanding - GETARUNS - which can deal with different levels of syntactic
and semantic ambiguity in the generation of a final structure, by accessing
computational lexical equipped with sub-categorization frames and appropriate
selectional restrictions applied to the attachment of complements and adjuncts.
The system also produces pronominal binding and instantiates the implicit
arguments, if needed, in order to complete the required Predicate Argument
structure which is licensed by the semantic component
La riscoperta del linguaggio - Conversazione con Tengan Daisuke
Five new orbitides, cyclolinopeptides <b>21</b>ā<b>25</b>, were identified in flaxseed oil
(<i>Linum usitatissimum</i>) extracts. Their HPLC-ESIMS
quasimolecular ion peaks at <i>m</i>/<i>z</i> 1097.7
(<b>21</b>), 1115.6 (<b>22</b>), 1131.6 (<b>23</b>), 1018.6 (<b>24</b>), and
1034.6 (<b>25</b>) [M + H]<sup>+</sup> corresponded to the molecular
formulae C<sub>59</sub>H<sub>89</sub>N<sub>10</sub>O<sub>10</sub>,
C<sub>58</sub>H<sub>87</sub>N<sub>10</sub>O<sub>10</sub>S, C<sub>58</sub>H<sub>87</sub>N<sub>10</sub>O<sub>11</sub>S, C<sub>53</sub>H<sub>80</sub>N<sub>9</sub>O<sub>9</sub>S, and C<sub>53</sub>H<sub>80</sub>N<sub>9</sub>O<sub>10</sub>S, respectively. Their structures were
elucidated by extensive HPLC-ESIMS/MS analyses, and their presence
was confirmed by precursor proteins identified in flax genomic DNA
sequence data. The amino acid sequences of these orbitides were confirmed
as [1ā10-NĪ±C]-GILVPPFFLI, [1ā10-NĪ±C]-GMLIPPFFVI,
[1ā10-NĪ±C]-G<i>O</i>LIPPFFVI, [1ā9-NĪ±C]-GMLVFPLFI,
and [1ā9-NĪ±C]-G<i>O</i>LVFPLFI for cyclolinopeptides <b>21</b>ā<b>25</b>, respectively. Previously reported
orbitides, [1ā9-NĪ±C]-ILVPPFFLI (<b>1</b>), [1ā9-NĪ±C]-MLIPPFFVI
(<b>2</b>), [1ā9-NĪ±C]-<i>O</i>LIPPFFVI
(<b>3</b>), [1ā8-NĪ±C]-MLVFPLFI (<b>7</b>),
and [1ā8-NĪ±C]-<i>O</i>LVFPLFI (<b>8</b>), were also present in flaxseed oil. The precursors of orbitides <b>21</b>, <b>22</b>, and <b>24</b> also produced orbitides <b>1</b>, <b>2</b>, and <b>7</b> by alternative cyclization.
Cyclolinopeptides <b>3</b>, <b>8</b>, <b>23</b>,
and <b>25</b> contain MetO (<i>O</i>) and are not
directly encoded, but are products of post-translational modification
of the Met present in <b>2</b>, <b>7</b>, <b>22</b>, and <b>24</b>, respectively. Sufficient cyclolinopeptide <b>23</b> was isolated for characterization via 1D (<sup>1</sup>H
and <sup>13</sup>C) and 2D (NOESY and HMBC) NMR spectroscopy. These
compounds have been named as cyclolinopeptides U, V, W, X, and Y for <b>21</b>, <b>22</b>, <b>23</b>, <b>24</b>, and <b>25</b>, respectively
Understanding the Diversity and Distribution of Cyclotides from Plants of Varied Genetic Origin
Cyclotides are a large family of
naturally occurring plant-derived
macrocyclic cystine-knot peptides, with more than 400 having been
identified in species from the Violaceae, Rubiaceae, Cucurbitaceae,
Fabaceae, and Solanaceae families. Nevertheless, their specialized
distribution within the plant kingdom remains poorly understood. In
this study, the diversity of cyclotides was explored through the screening
of 197 plants belonging to 43 different families. In total, 28 cyclotides
were sequenced from 15 plant species, one of which belonged to the
Rubiaceae and 14 to the Violaceae. Every Violaceae species screened
contained cyclotides, but they were only sparsely represented in Rubiaceae
and nonexistent in other families. The study thus supports the hypothesis
that cyclotides are ubiquitous in the Violaceae, and it adds to the
list of plants found to express kalata S and cycloviolacin O12. Finally,
previous studies suggested the existence of cyclotide isoforms with
either an Asn or an Asp at the C-terminal processing site of the cyclotide
domain within the precursor proteins. Here we found that despite the
discovery of a few cyclotides genuinely containing an Asp in loop
6 as evidenced by gene sequencing, deamidation of Asn during enzymatic
digestion resulted in the artifactual presence of Asp isoforms. This
result is consistent with studies suggesting that peptides can undergo
deamidation after being subjected to external factors, including pH,
temperature, and enzymatic digestion