Correlating comprehensive two-dimensional gas chromatography volatile profiles of chocolate with sensory analysis

The identification of key components relevant to sensory perception of quality from commercial chocolate samples was accomplished after chemometric processing of GC×GC-MS (Comprehensive Two-dimensional Gas Chromatography with Mass Spectrometric Detection) profiles corresponding to HS-SPME (Headspace Solid Phase Microextraction) extracts of the samples. Descriptive sensory evaluation of samples was carried out using Optimized Descriptive Profile (ODP) procedures, where sensory attributes of 24 commercial chocolate samples were used to classify them in two classes (low and high chocolate flavor). 2D Fisher Ratio analysis was applied to four-way chromatographic data tensors (1st dimension retention time 1tR × 2nd dimension retention time 2tR × m/z × sample), to identify the crucial areas on the chromatograms that resulted on ODP class separation on Principal Component Analysis (PCA) scores plot. Comparing the relevant sections of the chromatograms to the analysis of the corresponding mass spectra, it was possible to assess that most of the information regarding the sample main sensory attributes can be related to only 14 compounds (2,5-dimethylpyrazine, 2,6-dimethyl-4-heptanol, 1-octen-3-ol, trimethylpyrazine, β-pinene, o-cimene, 2-ethyl-3,5-dimethylpyrazine, tetramethylpyrazine, benzaldehyde, 1,3,5-trimethylbenzene, 6-methyl-5-hepten-2-one, limonene, benzeneethanol and 1,1-dimethylbutylbenzene) among the complex blend of volatiles found on these extremely complex samples

Minimal set of local measurements and classical communication for two-mode Gaussian state entanglement quantification

We develop the minimal requirements for the complete entanglement quantification of an arbitrary two-mode bipartite Gaussian state via local measurements and a classical communication channel. The minimal set of measurements is presented as a reconstruction protocol of local covariance matrices and no previous knowledge of the state is required but its Gaussian character. The protocol becomes very simple mostly when dealing with Gaussian states transformed to its standard form, since photocounting or intensity measurements define the whole set of entangled states. In addition, conditional on some prior information, the protocol is also useful for a complete global state reconstruction.981

Dispelling the myth that habitual caffeine consumption influences the performance response to acute caffeine supplementation

Objective: To investigate the influence of habitual caffeine intake on aerobic exercise performance responses to acute caffeine supplementation. Methods: A double-blind, crossover, counterbalanced study was performed. Forty male endurance-trained cyclists were allocated into tertiles according to their daily caffeine intake: low (58 ± 29 mg.d-1), moderate (143 ± 25 mg.d-1), and high consumers (351 ± 139 mg.d-1). Participants completed three trials in which they performed simulated cycling time-trials in the fastest time possible following ingestion of: caffeine (CAF: 6 mg.kg-1 BM), placebo (PLA), and no supplement (CON). Results: Mixed-model analysis revealed time-trial performance was significantly improved in CAF compared to PLA and CON (29.92±2.18 min vs 30.81±2.67 and 31.14±2.71 min; P = 0.05). Blood lactate and ratings of perceived exertion were not different between trials and tertiles (P>0.05). Conclusion: Performance effects of acute caffeine supplementation during a ~30 min cycling TT performance were not influenced by the level of habitual caffeine consumption

An evaluation of enteral nutrition practices and nutritional provision in children during the entire length of stay in critical care

<b>Background</b> Provision of optimal nutrition in children in critical care is often challenging. This study evaluated exclusive enteral nutrition (EN) provision practices and explored predictors of energy intake and delay of EN advancement in critically ill children.<p></p> <b>Methods</b> Data on intake and EN practices were collected on a daily basis and compared against predefined targets and dietary reference values in a paediatric intensive care unit. Factors associated with intake and advancement of EN were explored.<p></p> <b>Results</b> Data were collected from 130 patients and 887 nutritional support days (NSDs). Delay to initiate EN was longer in patients from both the General Surgical and congenital heart defect (CHD) Surgical groups [Median (IQR); CHD Surgical group: 20.3 (16.4) vs General Surgical group: 11.4 (53.5) vs Medical group: 6.5 (10.9) hours; p <= 0.001]. Daily fasting time per patient was significantly longer in patients from the General Surgical and CHD Surgical groups than those from the Medical group [% of 24 h, Median (IQR); CHD Surgical group: 24.0 (29.2) vs General Surgical group: 41.7 (66.7) vs Medical group: 9.4 (21.9); p <= 0.001]. A lower proportion of fluids was delivered as EN per patient (45% vs 73%) or per NSD (56% vs 73%) in those from the CHD Surgical group compared with those with medical conditions. Protein and energy requirements were achieved in 38% and 33% of the NSDs. In a substantial proportion of NSDs, minimum micronutrient recommendations were not met particularly in those patients from the CHD Surgical group. A higher delivery of fluid requirements (p < 0.05) and a greater proportion of these delivered as EN (p < 0.001) were associated with median energy intake during stay and delay of EN advancement. Fasting (31%), fluid restriction (39%) for clinical reasons, procedures requiring feed cessation and establishing EN (22%) were the most common reasons why target energy requirements were not met.<p></p> <b>Conclusions</b> Provision of optimal EN support remains challenging and varies during hospitalisation and among patients. Delivery of EN should be prioritized over other "non-nutritional" fluids whenever this is possible.<p></p&gt

The role of evolutive elastic properties in the performance of a sheet formed spring applied in multimedia car industry

The manufacturing process and the behavior of a sheet formed spring manufactured from an aluminum sheet is described and investigated in this work considering the specifications for the in-service conditions. The sheet formed spring is intended to be applied in car multimedia industry to replace bolted connections. Among others, are investigated the roles of the constitutive parameters and the hypothesis of evolutive elastic properties with the plastic work in the multi-step forming process and in working conditions.This research was sponsored by:a) Portugal Incentive System for Research and Technological Development. Project in co-promotion no 36265/2013 (Project HMIExcel - 2013-2015), andb) FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 - Programa Operacional Competitividade e Internacionalizacao (POCI) with the reference project POCI-01-0145-FEDER-006941.info:eu-repo/semantics/publishedVersio

24-Week β-alanine ingestion does not affect muscle taurine or clinical blood parameters in healthy males

Purpose: To investigate the effects of chronic beta-alanine (BA) supplementation on muscle taurine content, blood clinical markers and sensory side-effects. Methods: Twenty-five healthy male participants (age 27±4 years, height 1.75±0.09 m, body mass 78.9±11.7 kg) were supplemented with 6.4 g day−1 of sustained-release BA (N=16; CarnoSyn™, NAI, USA) or placebo (PL; N=9; maltodextrin) for 24 weeks. Resting muscle biopsies of the m. vastus lateralis were taken at 0, 12 and 24 weeks and analysed for taurine content (BA, N=12; PL, N=6) using high-performance liquid chromatography. Resting venous blood samples were taken every 4 weeks and analysed for markers of renal, hepatic and muscle function (BA, N=15; PL, N=8; aspartate transaminase; alanine aminotransferase; alkaline phosphatase; lactate dehydrogenase; albumin; globulin; creatinine; estimated glomerular filtration rate and creatine kinase). Results :There was a significant main effect of group (p=0.04) on muscle taurine, with overall lower values in PL, although there was no main effect of time or interaction effect (both p>0.05) and no differences between specific timepoints (week 0, BA: 33.67±8.18 mmol kg−1 dm, PL: 27.75±4.86 mmol kg−1 dm; week 12, BA: 35.93±8.79 mmol kg−1 dm, PL: 27.67±4.75 mmol kg−1 dm; week 24, BA: 35.42±6.16 mmol kg−1 dm, PL: 31.99±5.60 mmol kg−1 dm). There was no effect of treatment, time or any interaction effects on any blood marker (all p>0.05) and no self-reported side-effects in these participants throughout the study. Conclusions: The current study showed that 24 weeks of BA supplementation at 6.4 g day−1 did not significantly affect muscle taurine content, clinical markers of renal, hepatic and muscle function, nor did it result in chronic sensory side-effects, in healthy individuals. Since athletes are likely to engage in chronic supplementation, these data provide important evidence to suggest that supplementation with BA at these doses for up to 24 weeks is safe for healthy individuals

Soil-induced impacts on forest structure drive coarse woody debris stocks across central Amazonia

PublishedJournal Article© 2014, © 2014 Botanical Society of Scotland and Taylor & Francis. Background: Coarse woody debris (CWD) is an essential component in tropical forest ecosystems and its quantity varies widely with forest types. Aims: Relationships among CWD, soil, forest structure and other environmental factors were analysed to understand the drivers of variation in CWD in forests on different soil types across central Amazonia. Methods: To estimate CWD stocks and density of dead wood debris, 75 permanent forest plots of 0.5 ha in size were assessed along a transect that spanned ca. 700 km in undisturbed forests from north of the Rio Negro to south of the Rio Amazonas. Soil physical properties were evaluated by digging 2-m-deep pits and by taking auger samples. Results: Soil physical properties were the best predictors of CWD stocks; 37% of its variation was explained by effective soil depth. CWD stocks had a two-fold variation across a gradient of physical soil constraints (i.e. effective soil depth, anoxia and soil structure). Average biomass per tree was related to physical soil constraints, which, in turn, had a strong relationship with local CWD stocks. Conclusions: Soil physical properties appear to control average biomass per tree (and through this affect forest structure and dynamics), which, in turn, is correlated with CWD production and stocks