1,255 research outputs found
Chemometric modelling to relate antioxidants, neutral lipid fatty acids and flavour components in chicken breast
Relationships among quality factors in retailed free-range, corn-fed, organic, and conventional chicken breasts (9) were modeled using chemometric approaches. Use of principal component analysis (PCA) to neutral lipid composition data explained the majority (93%) of variability (variance) in fatty acid contents in 2 significant multivariate factors. PCA explained 88 and 75% variance in 3 factors for, respectively, flame ionization detection (FID) and nitrogen phosphorus (NPD) components in chromatographic flavor data from cooked chicken after simultaneous distillation extraction. Relationships to tissue antioxidant contents were modeled. Partial least square regression (PLS2), interrelating total data matrices, provided no useful models. By using single antioxidants as Y variables in PLS (1), good models (r2 values > 0.9) were obtained for alpha-tocopherol, glutathione, catalase, glutathione peroxidase, and reductase and FID flavor components and among the variables total mono and polyunsaturated fatty acids and subsets of FID, and saturated fatty acid and NPD components. Alpha-tocopherol had a modest (r2 = 0.63) relationship with neutral lipid n-3 fatty acid content. Such factors thus relate to flavor development and quality in chicken breast meat
Economic and social impacts of Integrated Aquaculture-Agriculture technologies in Bangladesh
This study estimated the adoption rate of integrated aquaculture-agriculture (IAA) technologies in Bangladesh and their impact on poverty and fish and food consumption in adopting households. We used a novel, simulation-based approach to impact assessment called Tradeoff Analysis for Multi-Dimensional Impact Assessment (TOA-MD). We used the TOA-MD model to demonstrate how it is possible to use available data to estimate adoption rates in relevant populations, and to quantify impacts on distributional outcomes such as poverty and food security, thus demonstrating ex ante the potential for further investment in technology dissemination. The analysis used baseline and end-of-project survey data from WorldFish-implemented Development of Sustainable Aquaculture Project (DSAP), promoting IAA. This dataset was used to simulate adoption and assess its impacts on poverty and food security in the target population. We found that, if adopted, IAA had a significant positive impact on reducing poverty and improving food security and income
AntiPlag: Plagiarism Detection on Electronic Submissions of Text Based Assignments
Plagiarism is one of the growing issues in academia and is always a concern
in Universities and other academic institutions. The situation is becoming even
worse with the availability of ample resources on the web. This paper focuses
on creating an effective and fast tool for plagiarism detection for text based
electronic assignments. Our plagiarism detection tool named AntiPlag is
developed using the tri-gram sequence matching technique. Three sets of text
based assignments were tested by AntiPlag and the results were compared against
an existing commercial plagiarism detection tool. AntiPlag showed better
results in terms of false positives compared to the commercial tool due to the
pre-processing steps performed in AntiPlag. In addition, to improve the
detection latency, AntiPlag applies a data clustering technique making it four
times faster than the commercial tool considered. AntiPlag could be used to
isolate plagiarized text based assignments from non-plagiarised assignments
easily. Therefore, we present AntiPlag, a fast and effective tool for
plagiarism detection on text based electronic assignments
Path Integral Approach to Fermionic Vacuum Energy in Non-parallel D1-Branes
The fermionic one loop vacuum energy of the superstring theory in a system of
non-parallel D1-branes is derived by applying the path integral formalism.Comment: 7 pages, no figur
Higher Fertilizer Inputs Increase Fitness Traits of Brown Planthopper in Rice.
Rice (Oryza sativa L.) is the primary staple food source for more than half of the world's population. In many developing countries, increased use of fertilizers is a response to increase demand for rice. In this study, we investigated the effects of three principal fertilizer components (nitrogen, phosphorus and potassium) on the development of potted rice plants and their effects on fitness traits of the brown planthopper (BPH) [Nilaparvata lugens (Stål) (Homoptera: Delphacidae)], which is a major pest of rice in Bangladesh and elsewhere. Compared to low fertilizer inputs, high fertilizer treatments induced plant growth but also favored BPH development. The BPH had higher survival, developed faster, and the intrinsic rate of natural increase (r m ) was higher on well-fertilized than under-fertilized plants. Among the fertilizer inputs, nitrogen had the strongest effect on the fitness traits of BPH. Furthermore, both the "Plant vigor hypothesis" and the "Plant stress hypothesis" were supported by the results, the former hypothesis more so than the latter. These hypotheses suggest that the most suitable/attractive hosts for insect herbivores are the most vigorous plants. Our findings emphasized that an exclusive focus on yield increases through only enhanced crop fertilization may have unforeseen, indirect, effects on crop susceptibility to pests, such as BPH
Paying attention to cardiac surgical risk: An interpretable machine learning approach using an uncertainty-aware attentive neural network
Machine learning (ML) is increasingly applied to predict adverse postoperative outcomes in
cardiac surgery. Commonly used ML models fail to translate to clinical practice due to
absent model explainability, limited uncertainty quantification, and no flexibility to missing
data. We aimed to develop and benchmark a novel ML approach, the uncertainty-aware
attention network (UAN), to overcome these common limitations. Two Bayesian uncertainty
quantification methods were tested, generalized variational inference (GVI) or a posterior
network (PN). The UAN models were compared with an ensemble of XGBoost models and
a Bayesian logistic regression model (LR) with imputation. The derivation datasets consisted
of 153,932 surgery events from the Australian and New Zealand Society of Cardiac
and Thoracic Surgeons (ANZSCTS) Cardiac Surgery Database. An external validation consisted
of 7343 surgery events which were extracted from the Medical Information Mart for
Intensive Care (MIMIC) III critical care dataset. The highest performing model on the external
validation dataset was a UAN-GVI with an area under the receiver operating characteristic
curve (AUC) of 0.78 (0.01). Model performance improved on high confidence samples
with an AUC of 0.81 (0.01). Confidence calibration for aleatoric uncertainty was excellent for
all models. Calibration for epistemic uncertainty was more variable, with an ensemble of
XGBoost models performing the best with an AUC of 0.84 (0.08). Epistemic uncertainty was
improved using the PN approach, compared to GVI. UAN is able to use an interpretable and
flexible deep learning approach to provide estimates of model uncertainty alongside stateof-
the-art predictions. The model has been made freely available as an easy-to-use web
application demonstrating that by designing uncertainty-aware models with innately explainable
predictions deep learning may become more suitable for routine clinical use.The ANZSCTS Cardiac Surgery Database
Program is funded by the Department of Health
(Victoria), the Clinical Excellence Commission
(NSW)Queensland Health (QLD)ANZSCTS Database Research
activities are supported through a National Health
and Medical Research Council Principal Research
Fellowship (APP 1136372)Program Grant
(APP 1092642
Tree-based survival analysis improves mortality prediction in cardiac surgery
Objectives: Machine learning (ML) classification tools are known to accurately
predict many cardiac surgical outcomes. A novel approach, ML-based survival
analysis, remains unstudied for predicting mortality after cardiac surgery. We
aimed to benchmark performance, as measured by the concordance index
(C-index), of tree-based survival models against Cox proportional hazards (CPH)
modeling and explore risk factors using the best-performing model.
Methods: 144,536 patients with 147,301 surgery events from the Australian and New
Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) national database were
used to train and validate models. Univariate analysis was performed using Student’s
T-test for continuous variables, Chi-squared test for categorical variables, and
stratified Kaplan-Meier estimation of the survival function. Three ML models were
tested, a decision tree (DT), random forest (RF), and gradient boosting machine
(GBM). Hyperparameter tuning was performed using a Bayesian search strategy.
Performance was assessed using 2-fold cross-validation repeated 5 times.
Results: The highest performing model was the GBM with a C-index of 0.803
(0.002), followed by RF with 0.791 (0.003), DT with 0.729 (0.014), and finally CPH
with 0.596 (0.042). The 5 most predictive features were age, type of procedure,
length of hospital stay, drain output in the first 4 h (ml), and inotrope use greater
than 4 h postoperatively.
Conclusion: Tree-based learning for survival analysis is a non-parametric and
performant alternative to CPH modeling. GBMs offer interpretable modeling of
non-linear relationships, promising to expose the most relevant risk factors and
uncover new questions to guide future research.The ANZSCTS National Cardiac Surgery Database Program is
funded by the Department of Health (Victoria)the Clinical
Excellence Commission (NSW)Queensland Health (QLD)Cardiac surgical units participating in
the registry. ANZSCTS Database Research activities are
supported through a National Health and Medical Research
Council Principal Research Fellowship (APP 1136372)Program Grant (APP 1092642
Schwinger Effect in Non-parallel D1-branes: A Path Integral Approach
We study the Schwinger effect in a system of non-parallel D1-branes for the
bosonic strings using the path integral formalism. We drive the string pair
creation rate by calculating the one loop vacuum amplitude of the setup in
presence of the background electric filed defined along one of the D1-branes.
We find an angle dependent minimum value for the background field and show that
the decaying of vacuum into string pairs takes place for the field above this
value. It is shown that in limit the vacuum
becomes stable and thus no pair creation occurs
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