Technical note: Application of the Box-Cox data transformation to animal science experiments.

Peltier, Morgan R.; Wilcox, C.J.; Sharp, Daniel C.

doi:10.2527/1998.763847x

Cited by 85 publications

(45 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…To meet the assumptions of normality and equal variances in the distributions of these analyses between cases and controls, the Box-Cox transformation was applied by allowing λ, the transformation parameter, to range between -4 and 4 in 0.05 increments [25]. The optimally transformed variables were then fitted to a general linear model (dependent variable).…”

Section: Discussionmentioning

confidence: 99%

Polymorphisms in methionine synthase reductase and betaine-homocysteine S-methyltransferase genes: Risk of placental abruption

Ananth

Elsasser

Kinzler

et al. 2007

Molecular Genetics and Metabolism

View full text Add to dashboard Cite

Objective-Methionine Synthase Reductase (MTRR) and Betaine-Homocysteine SMethyltransferase (BHMT) are 2 enzymes that regulate homocysteine metabolism. Elevated homocysteine (hyperhomocysteinemia) is associated with adverse pregnancy outcomes and vascular disease. We assessed whether polymorphisms in MTRR (66A→G; I22M) and BHMT (742G→A; R239Q) were associated with abruption. We further evaluated whether homocysteine levels differed between cases and controls for MTRR and BHMT genotypes.Methods-Data were derived from the New Jersey Placental Abruption Study (NJ-PAS)-an ongoing, multicenter, case-control study since August 2002. Women with a clinical diagnosis of abruption were recruited as incident cases (n=196), and controls (n=191) were matched to cases based on maternal race/ethnicity and parity. Total plasma homocysteine concentrations were evaluated in a subset of 136 cases and 136 controls. DNA was genotyped for the MTRR and BHMT polymorphisms.Results-Frequencies of the minor allele of MTRR were 40.8% and 42.2% in cases and controls, respectively (adjusted OR 0.79, 95% CI 0.45, 1.40). The corresponding rates for BHMT were 33. 9% and 31.7%, respectively (adjusted OR 1.93, 95% CI 0.99, 4.09). Distributions for the homozygous mutant form of MTRR were similar between cases and controls (OR 1.18, 95% CI 0.62, 2.24). The rate of homozygous mutant BHMT genotype was 2.8-fold (OR 2.82, 95% CI 1.84, 4.97) higher in cases than controls. Stratification of analyses based on maternal race did not reveal any patterns in association.Conclusions-In this population, there was an association between the homozygous mutant form of BHMT (742G→A) polymorphism and increased risk for placental abruption.Correspondence and reprint requests Cande V. Ananth, PhD, MPH, Division of Epidemiology and Biostatistics, Department of Obstetrics, Gynecology, and Reproductive Sciences, UMDNJ-Robert Wood Johnson Medical School, 125 Paterson Street, New Brunswick, NJ 08901-1977, Tel: (732) 235-6627, Email: cande.ananth@umdnj.edu Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ;5;7;8;9;10;11;12; 13;14;15;16]. Women with a previous abruption are at greatest risk (over 10-fold) risk of recurrent abruption, suggesting a strong genetic etiologic mechanism [17;18]. NIH Public AccessStudies have shown that folate deficiency is associated with increased homocysteine levels [19]. In a normally functioning metabolic state, methionine produces homocysteine as an intermediate step before either transsulfuration via cystathionine into cysteine or remethylation to methionine [20]. This remethylation may be ...

show abstract

Section: Discussionmentioning

confidence: 99%

Polymorphisms in methionine synthase reductase and betaine-homocysteine S-methyltransferase genes: Risk of placental abruption

Ananth

Elsasser

Kinzler

et al. 2007

Molecular Genetics and Metabolism

View full text Add to dashboard Cite

show abstract

“…THYER et al [2002]) it is used in e.g. econometrics [NELSON, GRANGER [1979], biology [PELTIER et al 1998] and others. 3.…”

Section: Methodsmentioning

confidence: 99%

The Application of Box–Cox Transformation to Determine the Standardised Precipitation Index (SPI), the Standardised Discharge Index (SDI) and to Identify Drought Events: Case Study in Eastern Kujawy (Central Poland)

Bartczak¹,

Glazik²,

Tyszkowski³

2014

Journal of Water and Land Development

View full text Add to dashboard Cite

The article presents the results of research into the transformation of series of hydro-meteorological data for determining dry periods with the Standardised Precipitation Index (SPI) and the Standardised Discharge Index (SDI). Time series from eight precipitation stations and five series of river discharge data in Eastern Kujawy (central Poland) were analysed for 1951-2010. The frequency distribution of the series for their convergence with the normal distribution was tested with the Shapiro-Wilk test and homogeneity with the Bartlett's test. The transformation of the series was done with the Box-Cox technique, which made it possible to homogenise the series in terms of variance. In Poland, the technique has never been used to determine the SPI. After the transformation the distributions of virtually all series complied with the normal distribution and were homogeneous. Moreover, a statistically significant correlation between the λ transformation parameter and the skewness of the series of monthly precipitation was observed. It was similar for the series of mean monthly discharges in the winter half-year and the hydrological year. The analysis indicates an alternate occurrence of dry and wet periods both in case of precipitation and run-offs. Drought periods coincided with low flow periods. Thus, the fluctuations tend to affect the development of agriculture more than long-term ones.

show abstract

“…Cognitive and global functioning variables were normalized with a Box-Cox data transformation 32 to enable use of parametric analyses. Analysis of variance (ANOVA) was used to compare group differences (BD vs. control and severe vs. moderate depression scores) in means.…”

Section: Discussionmentioning

confidence: 99%

Cognition and functioning in bipolar depression

Kapczinski

Narvaez

Magalhães

et al. 2016

Rev. Bras. Psiquiatr.

View full text Add to dashboard Cite

Objectives: Depressive symptoms are associated with worse outcomes in patients with bipolar disorder (BD). However, scarce data are available regarding neurocognitive profiles across different areas of functioning among BD patients with moderate and severe depression. Our objective was to assess cognition and global functioning in a group of patients with bipolar depression. Methods: Data were available for 100 patients with bipolar depression (78% female) and 70 controls (64% female) paired by age and education level. Cognitive function was assessed with a neuropsychological test battery. Functioning was assessed with the Functioning Assessment Short Test. Results: In patients, severe depression was associated with poorer cognitive performance on measures of executive function. Patients with severe depression showed worse global functioning than those with moderate depression (z = 2.54, p = 0.011). In patients with severe depression, lower global functioning was associated with lower scores in working memory (r = -0.200, p = 0.010), and executive function (r = -0.210, p = 0.007; and r = 0.293, p o 0.001). Conclusion: Our findings suggest cognitive impairment and global functioning impairment are associated with the severity of depressive symptoms in bipolar depression. Intensive treatment of depressive symptoms in patients with BD is crucial to improve cognitive functioning and, consequently, functional outcomes.

show abstract

Technical note: Application of the Box-Cox data transformation to animal science experiments.

Cited by 85 publications

References 8 publications

Polymorphisms in methionine synthase reductase and betaine-homocysteine S-methyltransferase genes: Risk of placental abruption

Polymorphisms in methionine synthase reductase and betaine-homocysteine S-methyltransferase genes: Risk of placental abruption

The Application of Box–Cox Transformation to Determine the Standardised Precipitation Index (SPI), the Standardised Discharge Index (SDI) and to Identify Drought Events: Case Study in Eastern Kujawy (Central Poland)

Cognition and functioning in bipolar depression

Contact Info

Product

Resources

About