A Bootstrap-VIP approach for selecting wavelength intervals in spectral imaging applications

Gosselin, Ryan; Rodrigue, Denis; Duchesne, Carl

doi:10.1016/j.chemolab.2009.09.005

Cited by 170 publications

(103 citation statements)

References 44 publications

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“…However, unlike principal components analysis, the ordination in PLSR creates latent variables that maximize the covariance between the chemical composition data and the response variable (germination percentage or radicle length). We used variable importance in projection (VIP) as the variable selection method (Gosselin et al 2010;Wold et al 1993). The loading of individual chemical components on the latent variables can be used as a measure of the importance of each chemical component to seed germination or seedling radicle length.…”

Section: Discussionmentioning

confidence: 99%

Interactions between allelochemicals and the microbial community affect weed suppression following cover crop residue incorporation into soil

Lou

Davis²,

Yannarell

2015

Plant Soil

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Background and aims The objective of this study is to understand how soil microorganisms interact with cover crop-derived allelochemicals to suppress weed germination and growth following cover crop residue incorporation. Methods We conducted a time series experiment crossing sterilized and non-sterilized soil with four different residue treatments. We measured weed seed germination rates, radicle elongation, and disease incidence in seed germination bioassays. We also monitored cover crop-derived, isoflavone allelochemicals in these bioassays. We partitioned the total weed suppression into three sources: microbe-only inhibition, residue-only inhibition, and the microbe-residue interaction. Results Microbial activity suppressed weed germination and growth for 30 days, while cover crop-derived allelochemicals provided suppression for a limited time. There was an antagonistic interaction between microbes and allelochemicals. This interaction was strongest for water-soluble allelochemicals, while residue fractions containing intact plant tissues retained greater suppressiveness even in the presence of a live microbial community. Conclusions Microbial activity can directly suppress weed germination and growth, but microorganisms also indirectly help weeds by degrading cover crop-derived allelochemicals. As a result of these interactions, cover crop-derived weed suppression in agricultural soils shifts from an early allelochemical-dominated phase to a later phase where microbial suppression is more important.

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Section: Discussionmentioning

confidence: 99%

Interactions between allelochemicals and the microbial community affect weed suppression following cover crop residue incorporation into soil

Lou

Davis²,

Yannarell

2015

Plant Soil

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“…Variables with a VIP value >1.5 were considered important in discriminating between groups (31) and were selected as the most relevant to explain the differences in metabolic profile. While a VIP >1 threshold is generally accepted (32)(33)(34), the cut-off applied in this study is more restrictive, reducing the possibility of obtaining false positive results.…”

Section: Exploratory Data Analysis and Orthogonal Signal Correction Pmentioning

confidence: 99%

Metabolomic Pattern Analysis after Mediterranean Diet Intervention in a Nondiabetic Population: A 1- and 3-Year Follow-up in the PREDIMED Study

et al. 2014

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The Mediterranean diet (MD) is considered a dietary pattern with beneficial effects on human health. The aim of this study was to assess the effect of an MD on urinary metabolome by comparing subjects at 1 and 3 years of follow-up, after an MD supplemented with either extra-virgin olive oil (MD+EVOO) or nuts (MD+Nuts), to those on advice to follow a control low-fat diet (LFD). Ninety-eight non-diabetic volunteers were evaluated, using metabolomic approaches, corresponding to MD+EVOO (n=41), MD+Nuts (n=27) or LFD (n=30) groups. The 1 H-NMR urinary profiles were examined at baseline, after 1 and 3 years of follow-up. Multivariate data analysis (OSC-PLS-DA and HCA) methods were used to identify the potential biomarker discriminating groups, exhibiting a urinary metabolome separation between MD groups against baseline and LFD. Results revealed that the most prominent hallmarks concerning MD groups were related to the metabolism of carbohydrates (3-hydroxybutyrate, citrate, cis-aconitate), creatine, creatinine, amino acids (proline, Nacetylglutamine, glycine, branched-chain amino acids and derived metabolites), lipids(oleic and suberic acids), and microbial co-metabolites (phenylacetylglutamine, pcresol). Otherwise, hippurate, trimethylamine-N-oxide, histidine and derivates (methylhistidines, carnosine, anserine) and xanthosine were predominant after LFD. The application of NMR-based metabolomics enabled the classification of individuals regarding their dietary pattern and highlights the potential of this approach for evaluating changes in the urinary metabolome at different time points of follow-up in response to specific dietary interventions.2

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“…The variable importance in projection (VIP) scores summarize the influence of individual variables on the PLS model, and give a measure useful to select the independent variables that contribute the most to the dependent variable's variance [73]. It is generally accepted in practice that variables having a VIP > 1.0 are highly influential, values between 0.8 < VIP < 1.0 indicate moderately influential variables, and variables with VIP < 0.8 are less important [73,74]. The coefficients of determination (R 2 ), the root mean square error (RMSE), the Nash-Sutcliffe efficiency (NSE) [75], and the percent bias (PBIAS) were calculated to evaluate the goodness of fit of the three ET a models.…”

Section: Statisticsmentioning

confidence: 99%

Observation and Estimation of Evapotranspiration from an Irrigated Green Roof in a Rain-Scarce Environment

Feng

Burian

Pardyjak

2018

Water

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While the rain-driven evapotranspiration (ET) process has been well-studied in the humid climate, the mixed irrigation and rain-driven ET process is less understood for green roof implementations in dry regions, where empirical observations and model parameterizations are lacking. This paper presents an effort of monitoring and simulating the ET process for an irrigated green roof in a rain-scarce environment. Annual ET rates for three weighing lysimeter test units with non-vegetated, sedums, and grass covers were 2.01, 2.52, and 2.69 mm d −1 , respectively. Simulations based on the three Penman-Monteith equation-derived models achieved accuracy within the reported range of previous studies. Compared to the humid climate, the overestimation of high ET rates by existing models is expected to cause a larger error in dry environments, where the enhanced ET process caused by repeated irrigations overlapped with hot, dry conditions often occurs during summer. The studied sedum species did not show significantly lower ET rates than native species, and could not effectively take advantage of the deep moisture storage. Therefore, native species, instead of the shallow-rooted species commonly recommended in humid climates, might be a better choice for green roofs in rain-scarce environments.

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A Bootstrap-VIP approach for selecting wavelength intervals in spectral imaging applications

Cited by 170 publications

References 44 publications

Interactions between allelochemicals and the microbial community affect weed suppression following cover crop residue incorporation into soil

Interactions between allelochemicals and the microbial community affect weed suppression following cover crop residue incorporation into soil

Metabolomic Pattern Analysis after Mediterranean Diet Intervention in a Nondiabetic Population: A 1- and 3-Year Follow-up in the PREDIMED Study

Observation and Estimation of Evapotranspiration from an Irrigated Green Roof in a Rain-Scarce Environment

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