Rejection Threshold Research Articles

How much can sodium chloride be substituted for potassium chloride without affecting the sensory acceptance of cracker-type biscuits?

Excessive sodium consumption is a worldwide public health concern. The substitution of sodium chloride (NaCl) for potassium chloride (KCl) has been adopted to reduce the sodium concentration in processed foods. The challenge is to make this substitution without affecting the sensory acceptance of foods. In this context, the objective was to determine from which concentrations the replacement of NaCl by KCl results in reduced acceptance (compromised acceptance threshold - CAT) and begins the sensory rejection (hedonic rejection threshold - HRT) of cracker-type biscuits. Using the hedonic thresholds methodology (HTM) by varying a stimulus, CAT and HRT were determined for the concentration of NaCl in crackers and, by varying two stimuli, CAT and HRT, for replacing NaCl with KCl in crackers were determined. Without the addition of KCl, the reduction in acceptance started to occur by reducing the NaCl content by around 60% (from 1.81% to 0.73%); and sensory rejection began to appear by reducing the NaCl content by approximately 93% (1.81% to 0.13%). Reduction in the acceptance started to occur by lowering the NaCl content by around 78% (from 1.81% to 0.397%), with the addition of 0.896% KCl. In addition, by adding KCl, it was possible to reduce 100% NaCl without sensory rejection of the crackers. With these results, cracker industries can reduce the sodium content of their products, contributing to the reduction of population salt intake.

Decrease in CD14++CD16+ Monocytes in Low-Immunological-Risk Kidney Transplant Patients with Subclinical Borderline Inflammation.

DefinitionWe determined the association between CD14++CD16+ monocytes and subclinical infiltrates that do not reach the histological threshold for rejection (≥Banff IA). We studied low-immunological-risk kidney-transplant recipients in a clinical trial (NCT02284464; EudraCT 2012-003298-24) whose protocol biopsy in the third month showed no significant changes or borderline lesions (BL). Flow cytometry was used to analyze the percentage of CD14++CD16+ monocytes in peripheral blood (PB) and blood from a fine-needle-aspiration biopsy (FNAB). A protocol biopsy was performed in 81 low-immunological-risk patients, of whom 15 were excluded (BK polyomavirus and rejection). The 28 (42.4%) with borderline lesions had significantly low levels of CD14++CD16+ in PB compared to patients with normal biopsies (7.9 ± 5.4 vs. 13.0 ± 12.8; p = 0.047). Patients without significant changes had similar percentages of CD14++CD16+ monocytes in the graft blood (GB) and FNAB blood. The percentage of these monocytes in the patients with an interstitial infiltrate, however, increased significantly in the FNAB blood compared to the GB: 16.9 ± 16.6 vs. 7.9 ± 5.4; p = 0.006. A difference of 50% in CD14++CD16+ in the GB versus the PB was a significant risk factor (p = 0.002) for BL, increasing the risk seven times. A decrease in CD14++CD16+ in the PB could be associated with the recruitment of these cells to the graft tissue in cases of subclinical BL inflammatory infiltrates below the threshold for rejection.

A multiple information model incorporating limited attention and information environment.

Rapid development of intelligent information equipment accelerates the expansion of mobile social network. Speed of information spreading is gradually growing, there are lots of changes in the scale and mode of information spreading. But the basic communication network is not developed and not mature, when online information platforms breakdown sometimes it happens to be when important information appears. Therefore, the research is done to solve these occasion problems, help network information platform filter hot news and discuss the reason that hot news exists longer than other news in the Internet. In this paper, a multiple information propagation model incorporating both local information environment and people’s limited attention is proposed based on Susceptible Infected Recovered (SIR) model. Two new concepts are introduced into the model: heat rate and popular rate, to measure the local information influence power and people’s limited attention to information respectively, which are key factors determining node state transformation instead of fixed probability. In order to analyze the influence from limited attention, a situation is designed that several pieces of information are popular successively. The theoretical analysis shows that the early popular information gets more attention than the later popular information, and more attention makes it easier to spread. Besides, numerical simulation is conducted in both uniform network and scale-free network. The simulation results show that the early popular information is less vulnerable to the increase of information acceptance threshold and more sensitive to the decrease of information rejection threshold than the later popular information. Moreover, the model can also be used in the case of large amount of information transmission without adding too much complexity. Reasons are given in the research that the top hot news exists very much longer than the other ones, and latter news which have same influence as top news are hard to get the same focus. Meanwhile, results in the research can provide some ways for the other researches in the related fields. They also help related information platforms to filter and push news and referable strategies to maintain hot news.

Throughput control and revenue optimization of a poultry product batcher

This article studies the optimal control of batching equipment in the poultry processing industry. The problem is to determine a control policy that maximizes the long-term average revenue while achieving a target throughput. This problem is formulated as a Markov Decision Process (MDP). The developed MDP model captures the unique characteristics of poultry processing operations, such as, the trade-off between giveaway and throughput. Structural properties of the optimal policy are derived for small-sized problems where batching equipment utilizes a single bin. Since the MDP model is numerically intractable for industry-sized problems, we propose a heuristic index policy with a Dynamic Rejection Threshold (DRT). The DRT heuristic is constructed based on the salient characteristics of the problem setting and is easy to implement in practice. Numerical experiments demonstrate that DRT performs well. We present an industry case study where DRT is benchmarked against current practice, which shows that the expected revenue can be potentially increased by over 2% (yielding an additional revenue between 750,000 and 2,270,000 Euros per year) through the use of DRT.

A Kernel Log-Rank Test of Independence for Right-Censored Data

We introduce a general nonparametric independence test between right-censored survival times and covariates, which may be multivariate. Our test statistic has a dual interpretation, first in terms of the supremum of a potentially infinite collection of weight-indexed log-rank tests, with weight functions belonging to a reproducing kernel Hilbert space (RKHS) of functions; and second, as the norm of the difference of embeddings of certain finite measures into the RKHS, similar to the Hilbert–Schmidt Independence Criterion (HSIC) test-statistic. We study the asymptotic properties of the test, finding sufficient conditions to ensure our test correctly rejects the null hypothesis under any alternative. The test statistic can be computed straightforwardly, and the rejection threshold is obtained via an asymptotically consistent Wild Bootstrap procedure. Extensive investigations on both simulated and real data suggest that our testing procedure generally performs better than competing approaches in detecting complex nonlinear dependence.

Pharmacological Control of Recipient NK Cell Function By Venetoclax Promotes Engraftment and Limits GVHD Following Reduced Intensity Conditioning without Impacting the Graft Versus AML Effect

BackgroundThe outcome of allogeneic haematopoietic stem cell transplantation (alloHSCT) is a complex interaction between conditioning regimen intensity (efficacy vs toxicity), recipient immunology (rejection vs engraftment) and donor immunology (rejection vs engraftment, and GVHD vs GVL). We must find means to lower conditioning toxicity, promote donor engraftment and limit GVHD in order to improve alloHSCT outcomes.Aims: Optimize the use of BCL2 inhibitors to modify recipient NK cell function in mouse models of alloHSCT in order to minimize GVHD severity and onset, and retain GVL responses.Hypothesis: Therapeutic targeting of recipient NK cell frequency or function pre-transplant will allow reduced intensity conditioning (RIC) and promote both donor T cell engraftment and GVL whilst reducing the risks of GVHD.MethodsMHC-mismatched mouse model of alloHSCT: Donor BM and T cells from BALB/c (H2Kd) mice were injected into irradiated C57BL/6 (H2Kb) recipients. On day 0, C57BL/6 WT, or Bcl2fl/fl (Bcl2 deleted in NKp46+NK1.1+ cells) recipients were irradiated with a RIC dose of 2 x 400 rad, before i.v. injection of 7.5e6 BALB/c BM + 1e6 T cells. C57BL/6 WT mice were also treated on day -2 and -1 by oral gavage with 100 mg/kg Venetoclax (ABT-199) or vehicle, before receiving alloHSCT. Mice were monitored for onset of GVHD and tested for early engraftment (day 7-14 post-transplant), and late engraftment (up to day 50).Graft-versus leukaemia (GVL) AML model:8e5mixed lineage leukaemia cells (MLL-AF9) were injected i.v. on day 0 into C57BL/6 WT recipients. On days 8 and 9 mice were treated by oral gavage with 100 mg/kg Venetoclax or vehicle, before receiving alloHSCT on day 10. Mouse survival and AML burden in the BM was measured on day 30.ResultsWe found that at both a myeloablative radiation dose (1200 rad) and a RIC non-myeloablative dose (800 rad), recipient NK cells were significantly more radio-resistant than either CD8+ T or myeloid cells. However, when a RIC dose of 800 rad was used during alloHSCT, the rejection threshold was not overcome and engraftment failed. We investigated both genetic and pharmacological models of recipient NK cell suppression during alloHSCT with RIC, to promote donor cell engraftment, reduce GVHD, and retain GVL.Conditional deletion of Bcl2 in NK cells results in a 90% loss of NK cells in vivo . Bcl2fl/fl alloHSCT RIC recipients showed robust donor engraftment, but absence of the pro-inflammatory cytokine storm and substantially less GVHD as determined by clinical scores and gut histology, compared to WT recipients. Pharmacological inhibition of BCL2 in WT recipients recapitulated the transplant findings in Bcl2fl/fl recipients. We found that BCL2 inhibition by Venetoclax, a BCL2 antagonist approved in the treatment of AML, resulted in NK cell apoptosis in human cells . We extended our observations in Bcl2fl/fl recipients to show that pharmacological inhibition of BCL2 in WT mice with just two doses of Venetoclax resulted in rapid depletion of NK cells. Over 35% of alloHSCT WT recipient mice pre-treated with Venetoclax developed long-term full donor engraftment even in the setting of RIC, with minimal GVHD, and retained potent GVL effects against pre-established AML.ConclusionsVenetoclax depletion of NK cells in WT alloHSCT recipients in combination with RIC was: 1) well-tolerated, 2) associated with low rates of GVHD, 3) resulted in long-term donor haematopoietic cell engraftment, and 4) maintained a GVL response. Recipient NK cell inhibition may therefore represent a means by which to deliver alloHSCT more safely. DisclosuresRitchie:Amgen Inc.: Honoraria.

Quality maintenance of salacca fruit with a carnauba wax coating containing orange oil and detection of sensory perception improvement with electroencephalography to appraise brain responses

The objective of this work was to study the effect of carnauba wax containing orange oil on physical qualities (weight loss, color, and firmness) and sensory perception after consumption. First, the appropriate essential oil for use with salacca fruit was investigated. Then, the best pairing of carnauba wax and orange oil was employed to study salacca preservation. Carnauba wax (2.5%) containing orange oil at a concentration of 0.04–0.16% was coated on salacca and examined for weight loss, color and firmness after storage for 9 d. Sensory perception in terms of sensory acceptance, rejection threshold and prevalent attributes related to aroma profiles was evaluated. The human brain response during salacca consumption was examined by electroencephalography (EEG). The results illustrated that salacca treated with carnauba wax containing orange oil at a concentration of 0.08% could maintain the desired qualities and provide moderate organoleptic approval of salacca. In addition, EEG demonstrated that consumption of orange oil-treated salacca could increase the alertness state of brain function in the human response. This finding can be used to apply orange oil to salacca fruit to enhance flavor, which was shown to achieve better consumer approval based on human brain activity.

Rejection Threshold Optimization using 3D ROC Curves: Novel Findings on Biomedical Datasets

Reject option is introduced in classification tasks to prevent potential misclassifications. Although optimization of error-reject trade-off has been widely investigated, it is shown that error rate itself is not an appropriate performance measure, when misclassification costs are unequal or class distributions are imbalanced. ROC analysis is proposed as an alternative approach to performance evaluation in terms of true positives (TP) and false positives (FP). Considering classification with reject option, we need to represent the tradeoff between TP, FP and rejection rates. In this paper, we propose 3D ROC analysis to determine the optimal rejection threshold as an analogy to decision threshold optimization in 2D ROC curves. We have demonstrated our proposed method with Naive Bayes classifier on Heart Disease dataset and validated the efficiency of the method on Pima Indians Diabetes dataset. Our experiments reveal that classification with optimized rejection threshold significantly improves true positive rates in medical datasets. Furthermore, false positive rates remain the same with rejection rates below 10%.

Interpretation of AlloMap® in Clinically Stable Combined Heart-Kidney Transplant Recipients

PurposeAs the number of patients undergoing heart-kidney transplantation (HKT) increases, new strategies for dual organ surveillance emerge. AlloMap® gene expression profiling is a widely adopted non-invasive tool utilized to monitor immune quiescence after heart transplant (HT) with the recommended threshold to rule out cellular rejection being 34. The interpretation of AlloMap® in combined HKT surveillance is not well defined. We aimed to determine the utility of AlloMap® for heart surveillance in stable HKT recipients.MethodsAlloMap® data collected from two transplant centers were reviewed retrospectively. Clinically stable patients with HKT (study group) and HT (control group) were included in the study. The HKT and HT cohorts were matched for age, ethnicity, sex, renal and cardiac function, and CMV serologic status. Serial AlloMap® distributions versus time were analyzed by two-sample Kolmogorov-Smirnov (K-S) analysis.ResultsThe study included 25 HKT recipients and 25 HT recipient matched controls transplanted between 1993 and 2020. Over the observed follow-up period (55 days to 18.4 years), there was no difference in AlloMap® scores between groups. In the time interval from 6 months to 24 months, the median AlloMap® scores were higher for HKT vs HT, 33.00 [95% CI, 29.87-34.08] vs 30.00 [95% CI, 28.99-30.92], p=0.028. The 1-year survival in both cohorts was 100% with no cardiac graft dysfunction or biopsy proven rejection (≥2R).ConclusionAlloMap® scores were slightly higher in HKT vs HT recipients between 6 months and 24 months post-transplant. As the HKT AlloMap® scores are near the threshold for possible acute cellular rejection, further investigation is warranted to define interpretation of AlloMap® in combined HKT surveillance. As the number of patients undergoing heart-kidney transplantation (HKT) increases, new strategies for dual organ surveillance emerge. AlloMap® gene expression profiling is a widely adopted non-invasive tool utilized to monitor immune quiescence after heart transplant (HT) with the recommended threshold to rule out cellular rejection being 34. The interpretation of AlloMap® in combined HKT surveillance is not well defined. We aimed to determine the utility of AlloMap® for heart surveillance in stable HKT recipients. AlloMap® data collected from two transplant centers were reviewed retrospectively. Clinically stable patients with HKT (study group) and HT (control group) were included in the study. The HKT and HT cohorts were matched for age, ethnicity, sex, renal and cardiac function, and CMV serologic status. Serial AlloMap® distributions versus time were analyzed by two-sample Kolmogorov-Smirnov (K-S) analysis. The study included 25 HKT recipients and 25 HT recipient matched controls transplanted between 1993 and 2020. Over the observed follow-up period (55 days to 18.4 years), there was no difference in AlloMap® scores between groups. In the time interval from 6 months to 24 months, the median AlloMap® scores were higher for HKT vs HT, 33.00 [95% CI, 29.87-34.08] vs 30.00 [95% CI, 28.99-30.92], p=0.028. The 1-year survival in both cohorts was 100% with no cardiac graft dysfunction or biopsy proven rejection (≥2R). AlloMap® scores were slightly higher in HKT vs HT recipients between 6 months and 24 months post-transplant. As the HKT AlloMap® scores are near the threshold for possible acute cellular rejection, further investigation is warranted to define interpretation of AlloMap® in combined HKT surveillance.

Hyperspectral Open Set Classification towards Deep Networks Based on Boxplot

Recently, hyperspectral imaging (HSI) supervised classification has achieved an astonishing performance by using deep learning. However, most of them take the ideal assumption of ‘closed set’, where all testing classes have been known during training. In fact, in the real world, new classes unseen in training may appear during testing. Obviously, traditional supervised classification methods cannot operate correctly in the real world, which requires classifiers not only to classify known classes, but reject the unknown in order to avoid false positives. This challenge is called ‘open set classification’(OSC). Considering the increased applications of deep learning in the real world, rejecting unknown classes during classification is of vital importance. To tackle it, we present a simple but effective HSI OSC method toward deep networks. In this method, we tighten the decision boundaries of SoftMax function of the last layer of the deep networks by using boxplots to analysis the statistical characteristics of the probability distribution of known classes and generate a proper rejection threshold for each known class. To test the performance of the proposed HSI OSC method, experiments are conducted on three HSI datasets. The results show that the proposed method outperforms existing state-of-the-art HSI OSC methods.

Consistent Allocation of Emission Responsibility in Fossil Fuel Supply Chains

Since 2016, Canada’s federal government has pledged to factor in upstream emissions during the environmental impact assessment of fossil fuel energy projects. The upstream emissions attributable to a proposed project could be compared against a rejection threshold—a maximum permissible level of emissions—or the firm could be mandated to offset the attributed emissions. We adopt a cooperative game-theoretic model and propose the nucleolus mechanism to apportion upstream emission responsibilities in a fossil fuel supply chain, represented by a directed tree, wherein the nodes correspond to various entities in the supply chain such as extractors, distributors, refineries, and end consumers. The nucleolus allocation avoids the distortionary effects of double counting and exhibits a certain consistency property that is especially important in a regulatory context wherein fossil fuel supply chains span multiple legal jurisdictions. We develop a polynomial-time algorithm to compute the nucleolus and further prove that it arises as the unique subgame perfect equilibrium allocation of a noncooperative game induced by two easily stated and verifiable policies, thereby providing an implementation framework. We then demonstrate the strong Nash stability of the nucleolus mechanism subject to the two policies, study its sensitivity to parameter changes, and characterize it on the basis of fairness considerations. Furthermore, under the common assumption that the emissions allocated to a firm and the resulting financial penalties do not impact the revenues from the firm’s core operations, we also provide lower-bound guarantees on the welfare gains it delivers to firms in the fossil fuel supply chain and on the incentives it offers such firms to adopt emission abatement technologies. Finally, we contextualize our discussion with a case study on a proposed expansion of the Trans Mountain pipeline in Western Canada. This paper was accepted by Chung Piaw Teo, optimization.

Age group determines the acceptability of protein derived off-flavour

Many older adults fail to meet their daily protein requirements, potentially due to social, physical and medical factors, including sensory and appetite changes. Additionally, our previous research has identified potential sulfurous off-flavours, originating from heat-treatment of protein ingredients, which could play a role in consumer acceptance. This study aims to determine the hedonic impact of these potential off-flavours when added to a dairy beverage, identify the specific off-flavour concentrations which cause rejection by consumers, and lastly investigate difference in acceptance between older and younger consumers. A rejection threshold (RjT) protocol was used, in combination with Best Estimate Thresholds (BET), whereby sulfurous flavours (dimethyl sulfide, dimethyl disulfide and dimethyl trisulfide), and diacetyl were added to create a range of concentrations. 95 participants (younger n = 49, 18–38 years; older n = 46, 60–79 years) tasted 7 pairs of samples (one blank and one with ascending off-flavour concentration) and selected their preferred samples. Sulfurous flavours negatively impacted consumer acceptance, however, the extent to which they impart a negative effect differs between age groups. Younger adults rejected samples containing low concentrations of sulfurous off-flavours (1.55 ppb), however, older adults rejected samples with concentrations over 3 times higher (5.08 ppb). When combined with sulfurous flavours, diacetyl increased the rejection threshold for both groups. In conclusion, these observations imply that a greater quantity of off-flavour may be present before acceptance is reduced in the older consumer group. Moreover, diacetyl demonstrates partial masking abilities of sulfurous off-flavours, and BET gave a more conservative estimate of acceptability. This knowledge will help guide sensory innovation of high-protein beverages for older consumers to support product acceptance and optimal intake.

Effects of spraying lactic acid and peroxyacetic acid on the quality and microbial community dynamics of vacuum skin-packaged chilled beef during storage

A long shelf life for fresh meat products is very important both to processors, retailers and consumers. In this work, the effect of repeat acid spraying on the shelf life of vacuum skin-packaged (VSP) chilled beef, as well as the quality and microbial community dynamics was evaluated. Carcasses were sprayed with 300 ppm peroxyacetic acid (PA) or 3% lactic acid (LA) three times during the chilling process, or one more time of LA spray before packaging (LLA). Quality, sensory attributes and microbial load of VSP beef during 32 days of storage at 4 °C were evaluated. The results showed that quality and sensory scores decreased over time for all treatments, but LLA treated samples were still above the rejection threshold at the end of the storage period. Moreover, the total volatile basic nitrogen value and the total viable counts were 15.0 mg/100 g and 7.2 log CFU/g for the control group, while acid treated groups remained below these two values until the end of the storage period. In particular LLA treated beef steaks exhibited the best preservation potential even at the end of storage. This is attributed to the reduction of Proteobacteria in LLA beef steaks shown by the bacterial diversity analysis via high-throughput sequencing, as well as the lower counts of B. thermosphacta and Enterobacteriaceae during storage. This indicates that LLA treatment has the potential to achieve a shelf life extension of VSP steaks without impacting on quality.

Low‐sugar strawberry yogurt: Hedonic thresholds and expectations

AbstractSugar reductions in processed foods can impact a product's sensory aspects and lead to financial losses for the companies that produce them. The aim of the present study was to determine sucrose levels in strawberry yogurt production that would not compromise acceptance (compromised acceptance threshold [CAT]) or result in sensory rejection (hedonic rejection threshold [HRT]). Second, the consumers' expectations were assessed by comparing sensory acceptability of the samples in blind and informed tests to verify the impact of reduced sugar content information on consumer perceptions. The ideal sweetness level of the sampled products was also evaluated. Finally, reduced sugar samples were evaluated with regards to meeting the new national requirements for reduced sucrose yogurts. Samples with a 9.13% sucrose concentration CAT and a 6.36% HRT were obtained when using the hedonic threshold methodology (HTM), from a control sample containing 10.64% sucrose. Over 14% of the sucrose in yogurt can be reduced without altering sensory acceptance, but a 40% or greater reduction in sucrose content may lead to sensory rejection of strawberry yogurt. The present study demonstrated that reductions which meet the required Brazilian standards can be made without affecting sensory acceptance.Practical ApplicationsThis was the first study to use the HTM to study sucrose reduction in dairy products. The results presented herein could have an important impact on industry, public policy makers, and consumers and may help dairy manufacturers meet established sugar reduction goals without affecting sensory acceptance. The effects are an important contribution to food science even when there are no sugar reduction requirements in play. Companies that have tested the impact of sugar reduction and studied how much sugar can be appropriately removed will be ahead of their competitors when these dietary requirements are implemented.

Hedonic thresholds and ideal sodium content reduction of bread loaves

Global public policies have advocated strategies for reducing sodium consumption due to the high incidence of non-communicable chronic diseases (NCDs) worldwide. The objectives of this study were to identify the bread loaves sodium content considered as ideal by the consumers and determine hedonic thresholds. In this descriptive cross-sectional study, 114 consumers evaluated the ideal sodium content in bread loaves by the Just About Right (JAR) test, (first sensorial stage) studying four decreased levels of sodium (10%, 20%, 30%, 40%) from the mean values observed from bread in 11 food composition tables from various regions of the world, and Brazil. This ideal sodium content was used as the control in pairwise acceptance tests with five other reduced-sodium samples of bread loaves (10%, 30%, 50%, 70%, 100% of reduction from the control), and hedonic threshold tests were performed with 156 consumers (a second stage sensorial test of five sessions). The data from the JAR were analyzed by a regression analysis graph and correlated with the consumption of salt and family income range by a Principal Component Analysis with a 5% significance level. In the Hedonic Threshold tests, each paired session was analyzed by Student's t-test (test t), and an adjusted regression graph was built. The Compromised Acceptance Threshold (CAT) was performed, where the calculated t corresponded to the tabulated t. In the Hedonic Rejection Threshold (HRT), the hedonic scale five (“indifferent” term) was considered. The average sodium content of bread marketed in different regions of the world was 457 mg Na/100 g of bread, and the ideal sodium content observed was 395 mg Na/100 g of bread. The gender, age and income family rates as well as attitudes and knowledge regarding the salt consumption of the trial consumers were not directly related to the evaluations of the bread loaves in the JAR test, according to the Principal Components Analysis at p ≤ 0.05. From this ideal content, a 42% reduction was possible according to the CAT test (267 mg Na/100 g of bread), and more reductions were acceptable until an 85% (to 58 mg Na/100 g of bread) reduction, as the samples began to be rejected according to HRT test. These findings demonstrated that this methodology can be applied to sodium reduction product formulations and bread as a food matrix. With this kind of methodology, it is possible to provide to the bakery industry a methodology to know a safe region to work on food reformulations and subsidize the formulation of new products without compromising consumer acceptability, in addition to meeting the demand for safer food.

3-Isobutyl-2-methoxypyrazine is neutrally perceived by consumers at usual concentrations in French Sauvignon and Fer wines from the Gaillac area

3-isobutyl-2-methoxypyrazine (IBMP) is a grape-derived aroma compound responsible for the bell pepper character of wine. It is still unclear whether this molecule is always negatively perceived by consumers. The objective of this study was to establish a consumer rejection threshold (CRT) for IBMP in French white and red wines from the Gaillac area made from Sauvignon and Fer respectively.The best estimate thresholds (BET) were determined by carrying out three-alternative forced choice (3-AFC) tests: 5.5 ng/L for Sauvignon and 16.8 ng/L for Fer. For the estimation of the CRT, consumers (n = 48) received pairs of samples consisting of a base wine and a base wine spiked with an ascending concentration of IBMP. They were asked to indicate which sample they preferred, and the CRT was calculated as the concentration for which the spiked sample was significantly rejected. CRTs were determined at 50 ng/L and 30 ng/L for Sauvignon and Fer respectively.Our findings indicate that IBMP is more acceptable in white wine than in red wine. As IBMP concentrations reported in the literature for Sauvignon and Fer are generally below CRT concentrations, IBMP appears to be neutrally perceived by consumers at usual concentrations in wines from Gaillac made from these two cultivars.Our findings tend to contradict the belief in the wine industry that consumers systematically reject ‘vegetative’ styles of wines, and do not encourage local winegrowers and winemakers to necessarily implement viticultural or enological practices to minimise IBMP concentrations in wine.

Volatile compounds and odour characteristics of five edible seaweeds preserved by high pressure processing: Changes during refrigerated storage

Edible seaweeds Chondrus crispus, Codium fragile, Himanthalia elongata, Ulva lactuca and Undaria pinnatifida, without any treatment (control seaweeds), were stored at 4 °C for 15, 30, 60, 15 and 30 days, respectively, until microbial counts exceeded 7 log cfu/g. High pressure processed (HPP) seaweeds, treated at 400 or 600 MPa for 5 min on day 2 after collection, were held at 4 °C until day 180. At the start of storage, 133 volatile compounds were detected in control seaweeds, with 89, 31, 45, 79 and 69 compounds found in C. crispus, C. fragile, H. elongata, U. lactuca and U. pinnatifida, respectively. Chemical groups including the highest number of compounds were aldehydes (24), alcohols (23), ketones (18), hydrocarbons (17) and benzene compounds (14). At the end of storage, 131 compounds were detected in control seaweeds, including 18 aldehydes, 28 alcohols, 23 ketones, 14 hydrocarbons and 13 benzene compounds, and 164 compounds in HPP-treated seaweeds, including 23 aldehydes, 31 alcohols, 19 ketones, 23 hydrocarbons and 15 benzene compounds. Increases in the levels of alcohols, benzene compounds and S-compounds and decreases in hydrocarbons, aldehydes and acids were recorded during storage of some control seaweeds, and increases in the levels of alcohols, acids and N-compounds and decreases in aldehydes, ketones and furans during storage of some HPP-treated seaweeds. Odour acceptance fell below rejection threshold as early as on day 15 for control U. lactuca while it remained acceptable until day 60 for control H. elongata and until day 180 for all the HPP-treated seaweeds. HPP treatment at 400 to 600 MPa for 5 min, in combination with refrigerated storage, is a useful tool for seaweed preservation, given its beneficial effects on microbial quality and sensory characteristics.

Urinary nitrate concentration as a marker for kidney transplant rejection

BackgroundEarly identification and treatment of kidney transplant rejection episodes is vital to limit loss of function and prolong the life of the transplanted kidney and recipient. Current practice depends on detecting a creatinine rise. A biomarker to diagnose transplant rejection at an earlier time point than current practice, or to inform earlier decision making to biopsy, could be transformative.It has previously been shown that urinary nitrate concentration is elevated in renal transplant rejection. Nitrate is a nitric oxide (NO) oxidation product. Transplant rejection upregulates NO synthesis via inducible nitric oxide synthase leading to elevations in urinary nitrate concentration. We have recently validated a urinary nitrate concentration assay which could provide results in a clinically relevant timeframe. Our aim was to determine whether urinary nitrate concentration is a useful tool to predict renal transplant rejection in the context of contemporary clinical practice.MethodsWe conducted a prospective observational study, recruiting renal transplant participants over an 18-month period. We made no alterations to the patients’ clinical care including medications, immunosuppression, diet and frequency of visits. We collected urine samples from every clinical attendance. We assessed the urinary nitrate to creatinine ratio (uNCR) between patient groups: routine attendances, biopsy proven rejection, biopsy proven no rejection and other call backs. uNCR was examined over time for those with biopsy proven transplant rejection. These four groups were compared using an ANOVA test.ResultsA total of 2656 samples were collected. uNCR during biopsy proven rejection, n = 15 (median 49 μmol/mmol, IQR 23–61) was not significantly different from that of routine samples, n = 164 (median 55 μmol/mmol, IQR 37–82) (p = 0.55), or biopsy proven no rejection, n = 12 (median 39 μmol/mmol, IQR 21–89) (P = 0.77).Overall uNCR was highly variable with no diagnostic threshold for kidney transplant rejection. Furthermore, within-patient uNCR was highly variable over time, and thus it was not possible to produce individualised patient thresholds to identify rejection. The total taking Tacrolimus was 204 patients, with no statistical difference between the uNCR of all those on Tacrolimus, against those not, p = 0.18.ConclusionThe urinary nitrate to creatinine ratio is not a useful biomarker for renal transplant rejection.

Boosting Deep Open World Recognition by Clustering

While convolutional neural networks have brought significant advances in robot vision, their ability is often limited to closed world scenarios, where the number of semantic concepts to be recognized is determined by the available training set. Since it is practically impossible to capture all possible semantic concepts present in the real world in a single training set, we need to break the closed world assumption, equipping our robot with the capability to act in an open world. To provide such ability, a robot vision system should be able to (i) identify whether an instance does not belong to the set of known categories (i.e. open set recognition), and (ii) extend its knowledge to learn new classes over time (i.e. incremental learning). In this work, we show how we can boost the performance of deep open world recognition algorithms by means of a new loss formulation enforcing a global to local clustering of class-specific features. In particular, a first loss term, i.e. global clustering, forces the network to map samples closer to the class centroid they belong to while the second one, local clustering, shapes the representation space in such a way that samples of the same class get closer in the representation space while pushing away neighbours belonging to other classes. Moreover, we propose a strategy to learn class-specific rejection thresholds, instead of heuristically estimating a single global threshold, as in previous works. Experiments on RGB-D Object and Core50 datasets show the effectiveness of our approach.

Exploring New and Modified Rejection-Type Thresholds Using Cricket Snack Crackers.

Recently, sensory threshold concepts have been expanded to include affective perceptions of foods and beverages, especially measures of product rejection; however, each threshold interpretation depends largely on the methodology employed. By substituting cricket powder for whole-wheat flour in snack crackers (0%, 5%, 10%, 15%, and 20%), we proposed modifications to two existing threshold methodologies: a modified consumer rejection threshold (M-CRT) using a 2-alternative choice (2-AC) preference test with “no preference” option; and a modified hedonic rejection threshold (M-HRT) based on less-than-neutral hedonic scores according to a one-sample t-test. We also proposed two new concepts: a rejection tolerance threshold (RTT) and an associated rejection range (RR), based on a binomial acceptability question and a probit regression model. These new methods provide more realistic interpretations of rejection-type thresholds based on user-defined allowable rejection levels, or “rejection tolerance” (for RTT), and a model-derived stimulus range (RR) to capture the rejection level of interest while providing flexibility for product formulation. All thresholds were investigated separately for color, flavor, texture and overall perception, elucidating differential sensorial effects of our novel ingredient on the food matrix. We suggest that conducting all demonstrated techniques in a single testing session gives a more expansive view of rejection thresholds while requiring minimal additional resources.