Covariation detection biases in sufficient and necessary situations.

In 4 experiments, university students played video games in which one action or cause covaried with an outcome. Judgments on sufficient and necessary causes were observed. On the basis of the obtained judgments, different computational models, Cheng and Novick's (1990a, 1992) probabilistic contrast ($\Delta$P rule) and the Rescorla-Wagner (1972) model were evaluated. In Experiments 1 and 2, for the positive contingencies, the participants judged sufficient and necessary causes differently; they also showed judgment deviations from the real contingencies. The $\Delta$P rule could not account for these data. An alternative weighted $\Delta$P rule was proposed and, along with the Rescorla-Wagner model, it successfully explained these results. In Experiment 3, negative contingencies were included. The pattern of judgements among the negative sufficient and necessary causes mirrored that of the positive contingencies but did not reach statistical significance. The $\Delta$P rule could not account for the judgments in Experiment 3, the adjusted $\Delta$P rule did not either. However, the Rescorla-Wagner model accounted for the results very well. In Experiment 4, the predictive power of these different models was compared. In general, the Rescorla-Wagner model remains the best descriptive model for explaining and predicting the patterns of contingency judgments

The Impact of Extreme Weather on Cattle Feeding Profits

While large feedlots commonly hedge corn and fed cattle prices, weather remains the largest uncontrollable component of production risk. This research examines the economic losses to cattle feeding associated with extreme weather. Profit losses are assessed using nonlinear regressions that relate weather outcomes, based on the Comprehensive Climate Index ( Mader, Johnson, and Gaughan , 2010 ), and their impact on production variables. Actuarially fair insurance premium rates are derived for an insurance product designed to mitigate the potential cost of extreme weather. Finally, we discuss additional issues associated with using weather-index insurance products and insuring feedlot cattle against adverse weather

NMF-based approach for missing values imputation of mass spectrometry metabolomics data

In mass spectrometry (MS)-based metabolomics, missing values (NAs) may be due to different causes, including sample heterogeneity, ion suppression, spectral overlap, inappropriate data processing, and instrumental errors. Although a number of methodologies have been applied to handle NAs, NA imputation remains a challenging problem. Here, we propose a non-negative matrix factorization (NMF)-based method for NA imputation in MS-based metabolomics data, which makes use of both global and local information of the data. The proposed method was compared with three commonly used methods: k-nearest neighbors (kNN), random forest (RF), and outlier-robust (ORI) missing values imputation. These methods were evaluated from the perspectives of accuracy of imputation, retrieval of data structures, and rank of imputation superiority. The experimental results showed that the NMF-based method is well-adapted to various cases of data missingness and the presence of outliers in MS-based metabolic profiles. It outperformed kNN and ORI and showed results comparable with the RF method. Furthermore, the NMF method is more robust and less susceptible to outliers as compared with the RF method. The proposed NMF-based scheme may serve as an alternative NA imputation method which may facilitate biological interpretations of metabolomics data

Quantitative evaluation of rat sciatic nerve degeneration using high-frequency ultrasound.

In this study, we evaluated the utility of using high-frequency ultrasound to non-invasively track the degenerative process in a rat model of peripheral nerve injury. Primary analyses explored spatial and temporal changes in quantitative backscatter coefficient (BSC) spectrum-based outcomes and B-mode textural outcomes, using gray level co-occurrence matrices (GLCMs), during the progressive transition from acute to chronic injury. As secondary analyses, correlations among GLCM and BSC spectrum-based parameters were evaluated, and immunohistochemistry were used to suggest a structural basis for ultrasound outcomes. Both mean BSC spectrum-based and mean GLCM-based measures exhibited significant spatial differences across presurgical and 1-month/2-month time points, distal stumps enclosed proximity to the injury site being particularly affected. The two sets of parameters sensitively detected peripheral nerve degeneration at 1-month and 2-month post-injury, with area under the receiver operating charactersitic curve > 0.8 for most parameters. The results also indicated that the many BSC spectrum-based and GLCM-based parameters significantly correlate with each other, and suggested a common structural basis for a diverse set of quantitative ultrasound parameters. The findings of this study suggest that BSC spectrum-based and GLCM-based analysis are promising non-invasive techniques for diagnosing peripheral nerve degeneration

DataSheet_1_Serum FT3/FT4, but not TSH is associated with handgrip strength in euthyroid U.S. population: evidence from NHANES.zip

ObjectiveAlthough several studies have examined the relationship between thyroid function and muscle strength, their population primarily derived from Asian areas, and their results were controversial. Thus, this study aimed to explore the association between thyroid function and handgrip strength (HGS) in the U.S. population.MethodsA total of 1,067 participants from NHANES were categorized into three different age groups including young (ResultsAfter adjustment for potential covariates, FT3/FT4, but not TSH was positively associated with HGS in middle age group (β=0.091, t=2.428, P=0.016). The subgroup analysis by sex revealed that the positive association between FT3/FT4 and HGS was observed in the middle age group for both male and female participants (β=0.163, t=2.121, P=0.035; β=0.157, t=2.180, P=0.031). The RCS analysis showed a statistically significant non-linear association between FT3/FT4 and HGS in overall population (P for non-linear=0.026). After adjustment for covariates, men with low HGS had a significant lower FT3/FT4 than those without low HGS in old age group (P=0.013). There was a significant increase in TSH level for female participants with low HGS in old age group compared to those with normal HGS (P=0.048).ConclusionsThis study demonstrated FT3/FT4, but not TSH, was positively associated with HGS in middle age group, and the different association was observed in men in middle age group when participants were stratified by sex. Future longitudinal cohort study should be conducted to reveal the causal relationship between thyroid function and muscle strength.</p

Environmental-adaptability analysis of an all polarization-maintaining fiber-based optical frequency comb

We demonstrate an all polarization-maintaining (PM) fiberbased optical frequency comb and provide the detailed environmental stability analysis results. The frequency comb has been built by commercial available PM fiber completely, and its static uncertainty in optical domain is 350 Hz in 1 s when referenced to a low noise oven controlled crystal oscillator. The acoustic resonant frequencies of the system have been measured. It is proved that acoustic-vibration induced phase noise could be eliminated by low pass vibration-isolation structure. Further, the existence of the optimum working temperature is illustrated. At this temperature (289.6 K), the out-loop integrated phase noise of f(r) and the temperature-drift induced instability of f(CEO) reach the lowest level 31.6 mu rad and 0 kHz/(mW center dot K) respectively. Finally, the system is proved to be stable under different humidity (18% similar to 80%) by a 240-day-long record of the f(CEO). (C) 2015 Optical Society of Americ