66 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
Liquid Chromatography–Mass Spectrometry Analysis Reveals Hydrolyzed Gluten in Beers Crafted To Remove Gluten
During brewing, gluten proteins may
be solubilized, modified, complexed,
hydrolyzed, and/or precipitate. Gluten fragments that persist in conventional
beers render them unsuitable for people with celiac disease (CD) or
gluten intolerance. Barley-based beers crafted to remove gluten using
proprietary precipitation and/or application of enzymes, e.g. prolyl
endopeptidases (PEP) that degrade the proline-rich gluten molecules,
are available commercially. Gluten measurement in fermented products
remains controversial. The industry standard, a competitive ELISA,
may indicate gluten values <20 mg/kg, which is deemed safe for
people with CD. However, in this study, liquid chromatography–mass
spectrometry analyses revealed gluten peptides derived from hydrolyzed
fragments, many >30 kDa in size. Barley gluten (hordeins) were
detected
in all beers analyzed with peptides representing all hordein classes
detected in conventional beers but also, alarmingly, in many gluten-reduced
beers. It is evident that PEP digestion was incomplete in several
commercial beers, and peptides comprising missed cleavages were identified,
warranting further optimization of PEP application in an industrial
setting
What is in a Beer? Proteomic Characterization and Relative Quantification of Hordein (Gluten) in Beer
The suite of prolamin proteins present in barley flour was characterized in this study, in which we provide spectral evidence for 3 previously characterized prolamins, 8 prolamins with only transcript evidence, and 19 genome-derived predicted prolamins. An additional 9 prolamins were identified by searching the complete spectral set against an unannotated translated EST database. Analyses of wort, the liquid extracted from the mashing process during beer production, and beer were undertaken and a similar suite of prolamins were identified. We have demonstrated by using tandem mass spectrometry that hordeins are indeed present in beer despite speculation to the contrary. Multiple reaction monitoring (MRM) mass spectrometry was used for the rapid analyses of hordein in barley (<i>Hordeum vulgare</i> L.) beer. A selection of international beers were analyzed and compared to the results obtained with hordein deletion beers. The hordein deletion beers were brewed from grains carrying mutations that prevented the accumulation of either B-hordeins (Risø 56) or C-hordeins (Risø 1508). No intact C-hordeins were detected in beer, although fragments of C-hordeins were present in wort. Multiple reaction monitoring analysis of non-barley based gluten (hordein)-free beers targeting the major hordein protein families was performed and confirmed the absence of hordein in several gluten-free commercial beers
Comparison of Gluten Extraction Protocols Assessed by LC-MS/MS Analysis
The efficiency of gluten extraction
is of critical importance to the results derived from any analytical
method for gluten detection and quantitation, whether it employs reagent-based
technology (antibodies) or analytical instrumentation (mass spectrometry).
If the target proteins are not efficiently extracted, the end result
will be an under-estimation in the gluten content posing a health
risk to people affected by conditions such as celiac disease (CD)
and nonceliac gluten sensitivity (NCGS). Five different extraction
protocols were investigated using LC-MRM-MS for their ability to efficiently
and reproducibly extract gluten. The rapid and simple “IPA/DTT”
protocol and related “two-step” protocol were enriched
for gluten proteins, 55/86% (trypsin/chymotrypsin) and 41/68% of all
protein identifications, respectively, with both methods showing high
reproducibility (CV < 15%). When using multistep protocols, it
was critical to examine all fractions, as coextraction of proteins
occurred across fractions, with significant levels of proteins existing
in unexpected fractions and not all proteins within a particular gluten
class behaving the same
What is in a Beer? Proteomic Characterization and Relative Quantification of Hordein (Gluten) in Beer
The suite of prolamin proteins present in barley flour was characterized in this study, in which we provide spectral evidence for 3 previously characterized prolamins, 8 prolamins with only transcript evidence, and 19 genome-derived predicted prolamins. An additional 9 prolamins were identified by searching the complete spectral set against an unannotated translated EST database. Analyses of wort, the liquid extracted from the mashing process during beer production, and beer were undertaken and a similar suite of prolamins were identified. We have demonstrated by using tandem mass spectrometry that hordeins are indeed present in beer despite speculation to the contrary. Multiple reaction monitoring (MRM) mass spectrometry was used for the rapid analyses of hordein in barley (<i>Hordeum vulgare</i> L.) beer. A selection of international beers were analyzed and compared to the results obtained with hordein deletion beers. The hordein deletion beers were brewed from grains carrying mutations that prevented the accumulation of either B-hordeins (Risø 56) or C-hordeins (Risø 1508). No intact C-hordeins were detected in beer, although fragments of C-hordeins were present in wort. Multiple reaction monitoring analysis of non-barley based gluten (hordein)-free beers targeting the major hordein protein families was performed and confirmed the absence of hordein in several gluten-free commercial beers
What is in a Beer? Proteomic Characterization and Relative Quantification of Hordein (Gluten) in Beer
The suite of prolamin proteins present in barley flour was characterized in this study, in which we provide spectral evidence for 3 previously characterized prolamins, 8 prolamins with only transcript evidence, and 19 genome-derived predicted prolamins. An additional 9 prolamins were identified by searching the complete spectral set against an unannotated translated EST database. Analyses of wort, the liquid extracted from the mashing process during beer production, and beer were undertaken and a similar suite of prolamins were identified. We have demonstrated by using tandem mass spectrometry that hordeins are indeed present in beer despite speculation to the contrary. Multiple reaction monitoring (MRM) mass spectrometry was used for the rapid analyses of hordein in barley (<i>Hordeum vulgare</i> L.) beer. A selection of international beers were analyzed and compared to the results obtained with hordein deletion beers. The hordein deletion beers were brewed from grains carrying mutations that prevented the accumulation of either B-hordeins (Risø 56) or C-hordeins (Risø 1508). No intact C-hordeins were detected in beer, although fragments of C-hordeins were present in wort. Multiple reaction monitoring analysis of non-barley based gluten (hordein)-free beers targeting the major hordein protein families was performed and confirmed the absence of hordein in several gluten-free commercial beers
Quantification of Hordeins by ELISA: The Correct Standard Makes a Magnitude of Difference
<div><p>Background</p><p>Coeliacs require a life-long gluten-free diet supported by accurate measurement of gluten (hordein) in gluten-free food. The gluten-free food industry, with a value in excess of $6 billion in 2011, currently depends on two ELISA protocols calibrated against standards that may not be representative of the sample being assayed.</p> <p>Aim</p><p>The factors affecting the accuracy of ELISA analysis of hordeins in beer were examined.</p> <p>Results</p><p>A simple alcohol-dithiothreitol extraction protocol successfully extracts the majority of hordeins from barley flour and malt. Primary hordein standards were purified by FPLC. ELISA detected different classes of purified hordeins with vastly different sensitivity. The dissociation constant (Kd) for a given ELISA reaction with different hordeins varied by three orders of magnitude. The Kd of the same hordein determined by ELISA using different antibodies varied by up to two orders of magnitude. The choice of either ELISA kit or hordein standard may bias the results and confound interpretation.</p> <p>Conclusions</p><p>Accurate determination of hordein requires that the hordein standard used to calibrate the ELISA reaction be identical in composition to the hordeins present in the test substance. In practice it is not feasible to isolate a representative hordein standard from each test food. We suggest that mass spectrometry is more reliable than ELISA, as ELISA enumerates only the concentration of particular amino-acid epitopes which may vary between different hordeins and may not be related to the absolute hordein concentration. MS quantification is undertaken using peptides that are specific and unique enabling the quantification of individual hordein isoforms.</p> </div
What is in a Beer? Proteomic Characterization and Relative Quantification of Hordein (Gluten) in Beer
The suite of prolamin proteins present in barley flour was characterized in this study, in which we provide spectral evidence for 3 previously characterized prolamins, 8 prolamins with only transcript evidence, and 19 genome-derived predicted prolamins. An additional 9 prolamins were identified by searching the complete spectral set against an unannotated translated EST database. Analyses of wort, the liquid extracted from the mashing process during beer production, and beer were undertaken and a similar suite of prolamins were identified. We have demonstrated by using tandem mass spectrometry that hordeins are indeed present in beer despite speculation to the contrary. Multiple reaction monitoring (MRM) mass spectrometry was used for the rapid analyses of hordein in barley (<i>Hordeum vulgare</i> L.) beer. A selection of international beers were analyzed and compared to the results obtained with hordein deletion beers. The hordein deletion beers were brewed from grains carrying mutations that prevented the accumulation of either B-hordeins (Risø 56) or C-hordeins (Risø 1508). No intact C-hordeins were detected in beer, although fragments of C-hordeins were present in wort. Multiple reaction monitoring analysis of non-barley based gluten (hordein)-free beers targeting the major hordein protein families was performed and confirmed the absence of hordein in several gluten-free commercial beers
Brewing protocols for standard beers.
<p>This is was previously published in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056456#pone.0056456-Colgrave1" target="_blank">[49]</a> and is reproduced here with permission for clarity.</p
The effect of DTT, hydrogen peroxide and urea on the ELISA response.
<p>The response of ELISA Systems sandwich assay containing total Sloop hordein (500 ppb) and either (A) DTT, or H<sub>2</sub>O<sub>2</sub> or (B) urea, diluted in ED buffer and added to the ELISA wells at the concentration indicated above and processed as described.</p
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