1,536 research outputs found
Panel performance: Modelling variation in sensory profiling data by multiway analysis
Sensory profiling data is essentially three-way data where samples, attributes and assessors are the three dimensions of information. It is common practice to average over the assessors and focus the analysis on the relations between samples and sensory descriptors. However, since assessor reliability can not be controlled in advance, posthoc analysis on assessors is needed to assess performance of the individual and at the panel level. For this purpose, multiway analysis is a very efficient data method as it provides information on samples, attributes and assessors, simultaneously [1]. PARAllel FACtor (PARAFAC) analysis is one of the most used multiway methods in sensory analysis [2][3]. It is based on two basic assumptions: 1) there exist latent variables behind the identified sensory descriptors describing the variation among the products; 2) assessors have different sensitivities to these common latent variables. However, assessors may perceive the factors differently, so the assumption of âcommon latent variablesâ becomes questionable. This may happen when the panel is not well trained and/or the samples present subtle differences difficult to detect.
In this work a more flexible approach to the analysis of sensory data is presented. Specifically, the work proposes to use PARAFAC2 modelling [4] as it allows each assessor to have an individual idiosyncratic perceptive model. The data was obtained from a descriptive sensory analysis of organic milk samples. Results show that PARAFAC2 is very useful to highlight disagreement in the panel on specific attributes and to detect outlying assessors. In addition, by using PARAFAC2 an improvement in the description of samples is also achieved. On the other hand, PARAFAC has to be preferred to PARAFAC2 when a good panel agreement is observed, since it provides more stable solutions and no further gain in information is obtained from PARAFAC2. Finally, the work proposes an index to measure the performance of each assessor based on individual sensitivity and reproducibility
Composition of volatile compounds in bovine milk heat treated by instant infusion pasteurization and correlation to sensory analysis
Volatile compounds in skim milk and nonstandardised milk subjected to instant infusion pasteurisation at 80°C, 100°C and 120°C were compared with raw milk, high temperature short time pasteurised milk and milk pasteurised at 85°C/30 s. The composition of volatile compounds differed between infusion pasteurisation treated samples and the reference pasteurisations. The sensory properties of skim milk subjected to instant infusion pasteurisation were described by negative attributes, such as cardboard sour and plastic flavours, which are not associated normally with fresh milk. Partial least squares modelling showed good correlation between the volatile compounds and the sensory properties, indicating the predictive and possible causal importance of the volatile compounds for the sensory characteristics
Monitoring panel performance within and between sensory experiments by multi-way analysis
In sensory analysis a panel of trained assessors evaluates a set of samples
according to specific sensory descriptors. The training improves objectivity and
reliability of assessments. However, there can be individual differences between
assessors left after the training that should be taken into account in the analysis.
Monitoring panel performance is then crucial for optimal sensory evaluations. The
quality of the results is strongly dependent on the performance of each assessor and
of the panel as a whole. The present work proposes to analyze the panel performance
within single sensory evaluations and between consecutive evaluations. The
basic idea is to use multi-way models to handle the three-way nature of the sensory
data. Specifically, a PARAFAC model is used to investigate the panel performance
in the single experiment. N-PLS model is used to test the predictive ability of the
panel on each experiment. A PARAFAC model is also used for monitoring panel
performance over different experiments
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Synthesis and evaluation of designed PKC modulators for enhanced cancer immunotherapy.
Bryostatin 1 is a marine natural product under investigation for HIV/AIDS eradication, the treatment of neurological disorders, and enhanced CAR T/NK cell immunotherapy. Despite its promising activity, bryostatin 1 is neither evolved nor optimized for the treatment of human disease. Here we report the design, synthesis, and biological evaluation of several close-in analogs of bryostatin 1. Using a function-oriented synthesis approach, we synthesize a series of bryostatin analogs designed to maintain affinity for bryostatin's target protein kinase C (PKC) while enabling exploration of their divergent biological functions. Our late-stage diversification strategy provides efficient access to a library of bryostatin analogs, which per our design retain affinity for PKC but exhibit variable PKC translocation kinetics. We further demonstrate that select analogs potently increase cell surface expression of CD22, a promising CAR T cell target for the treatment of leukemias, highlighting the clinical potential of bryostatin analogs for enhancing targeted immunotherapies
O Brasil pĂłs-1822:: nem tĂŁo moderno, nem tĂŁo conservador
This article deals with the accommodation of ideas in nineteenth - century Brazil, more specifically of the liberals in the economy and how they reverberated in the political environment of the country. There was a gap between theory and practice, for action departed from the idea of ââthe ruling class as an example and focus of the article, the slavery that was criticized by the European liberal discourse, but found resistance among the Brazilian liberals. Thus, liberal ideas, such as free trade, the right to property and individualism, were defended in the economy, however, were rejected when referring to slavery, which persisted in Brazil. To demonstrate this discrepancy between practice x theory, we use Alfredo Bosi, Roberto Schwarz and Carlos Lessa.Este artĂculo trata sobre la acomodaciĂłn de ideas en el Brasil del siglo XIX, mĂĄs especĂficamente de los liberales en la economĂa y cĂłmo repercutieron en el entorno polĂtico del paĂs. Hubo una brecha entre la teorĂa y la prĂĄctica, ya que la acciĂłn se apartĂł de la idea de la clase dominante como ejemplo y enfoque del artĂculo, la esclavitud que fue criticada por el discurso liberal europeo, pero que encontrĂł resistencia entre los liberales brasileĂąos. AsĂ, las ideas liberales, como el libre comercio, el derecho a la propiedad y el individualismo, fueron defendidas en la economĂa, sin embargo, fueron rechazadas cuando se referĂan a la esclavitud, que persistĂa en Brasil. Para demostrar esta discrepancia entre la prĂĄctica y la teorĂa, usamos a Alfredo Bosi, Roberto Schwarz y Carlos Lessa.O presente artigo trata da acomodação de ideias no Brasil do sĂŠculo XIX, mais especificamente das liberais na economia e como reverberaram no meio polĂtico do paĂs. Havia uma distância entre a teoria e a prĂĄtica, pois a ação se afastava da ideia da classe dominante, como exemplo, e foco do artigo, a escravidĂŁo que era criticada pelo discurso liberal europeu, mas encontrava resistĂŞncia entre os liberais brasileiros. Assim sendo, ideias liberais, como livre comĂŠrcio, direito Ă propriedade e individualismo, eram defendidas na economia, no entanto, eram rechaçadas quando se referiam Ă escravidĂŁo, que perdurava no Brasil. Para demonstrar essa discrepância entre prĂĄtica x teoria, utilizam-se Alfredo Bosi, Roberto Schwarz e Carlos Lessa
Differential cross section for neutron-proton bremsstrahlung
The neutron-proton bremsstrahlung process is known to be
sensitive to meson exchange currents in the nucleon-nucleon interaction. The
triply differential cross section for this reaction has been measured for the
first time at the Los Alamos Neutron Science Center, using an intense, pulsed
beam of up to 700 MeV neutrons to bombard a liquid hydrogen target. Scattered
neutrons were observed at six angles between 12 and 32, and the
recoil protons were observed in coincidence at 12, 20, and
28 on the opposite side of the beam. Measurement of the neutron and
proton energies at known angles allows full kinematic reconstruction of each
event. The data are compared with predictions of two theoretical calculations,
based on relativistic soft-photon and non-relativistic potential models.Comment: 5 pages, 3 figure
Comparison of three fast sensory profiling methods, check-all-that-apply (CACT), CACT with intensity rating, and Napping to study consumers' perception of eight beers
The double [3+2] photocycloaddition reaction
One of a synthetic organic chemistsâ greatest challenges is to create step-efficient routes toward compounds with high molecular complexity. Therefore, reactions such as the meta
photocycloaddition of an olefin to a benzene derivative, which provide more than one bond in a single step are of significant importance. It this remarkable reaction three new Ď bonds, three new rings and up to six new stereocenters are formed simultaneously. Additional complexity can be added by tethering the two reacting partners together and this form of the reaction has found many uses in natural product synthesis.
In this work a remarkable double [3+2] photocycloaddition reaction is reported that results in the formation of a complex cis, cis, cis, trans-[5, 5, 5, 5] fenestrane derivative from a simple flat aromatic acetal with two branching alkenes. During this dramatic transformation four carboncarbon bonds, five new rings and seven new stereocenters are created in a single one-pot process using only UV light. The reaction occurs in a sequential manner from the linear meta photocycloadduct, via a secondary [3+2] addition of the alkene across the cyclopropane of the adduct. In addition, an angular meta photocycloadduct also produced in the initial addition step, undergoes an alternative fragmentation-translocation photoreaction to afford a silphinene-like angular tricyclic compound.
In this work the investigation of this newly discovered process is discussed via the synthesis and subsequent irradiation of a series of photosubstrates containing different functional groups in the arene-alkene tether. In addition, attempts toward the synthesis of alternative structures using the same double [3+2] photocycloaddition are reported
Oligocarbonate Molecular Transporters: Oligomerization-Based Syntheses and Cell-Penetrating Studies
A new family of guanidinium-rich molecular transporters featuring a novel oligocarbonate backbone with 1,7-side chain spacing is described. Conjugates can be rapidly assembled irrespective of length in a one-step oligomerization strategy that can proceed with concomitant introduction of probes (or by analogy drugs). The new transporters exhibit excellent cellular entry as determined by flow cytometry and fluorescence microscopy, and the functionality of their drug delivery capabilities was confirmed by the delivery of the bioluminescent small molecule probe luciferin and turnover by its intracellular target enzyme
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