An oxidative NHC-catalyzed synthesis of tricyclic dihydropyranones with three contiguous stereocenters has been developed. Studies the mechanism suggest that rate-determining step is Breslow intermediate formation.

Here is a puzzle: in what area of organic synthesis research are synthetic organic chemists a minority? According to Albert Eschenmoser, it is in the field of prebiotic chemistry: the study of the reactions and molecules that led to the emergence of life on earth. Biologists, mathematicians, and astronomers have traditionally weighed in on this problem proportionally more than organic chemists....

OBJECTIVE The aim of this study was to analyze the temporal evolution of melanoma incidence in the department of the Bas-Rhin, France, and to study the evolution of tumor thickness. DESIGN Retrospective study including all histologically proven melanomas recorded at the cancer registry of the department of the Bas-Rhin between January 1980 and December 1992 and at the Cutaneous Histopathology...

The Liu estimator has consistently been demonstrated to be an attractive shrinkage method for reducing the effects of multicollinearity. The Poisson regression model is a well-known model in applications when the response variable consists of count data. However, it is known that multicollinearity negatively affects the variance of the maximum likelihood estimator (MLE) of the Poisson regressio...

Inverse sampling design is generally considered to be appropriate technique when the population is divided into two subpopulations, one of which contains only few units. In this paper, we derive the Horvitz-Thompson estimator for the population mean under inverse sampling designs, where subpopulation sizes are known. We then introduce an alternative unbiased estimator, corresponding to post-st...

This paper identifies several serious problems with the widespread use of ANOVAs for the analysis of categorical outcome variables such as forced-choice variables, question-answer accuracy, choice in production (e.g. in syntactic priming research), et cetera. I show that even after applying the arcsine-square-root transformation to proportional data, ANOVA can yield spurious results. I discuss ...

BACKGROUND The influence of psychiatric intervention on cancer outcome remains a topic of considerable debate. We previously reported the survival benefits for 68 patients with malignant melanoma 5 to 6 years following their participation in a structured psychiatric group intervention. In this article, we report the effects of the intervention on disease outcome in these same patients at the 10...

Benzoin (and neither the Breslow intermediate nor the NHC-aldehyde tetrahedral adduct) has been unambiguously identified as the oxidised species in aerobic NHC-catalysed aldehyde esterifications.

The aim of this study was to audit all malignant melanomas confirmed histologically in the Scarborough Health District over six years, prompted by the continuing rise in incidence rate nationally and relatively high number of malignant melanomas excised by general practitioners (GPs) in this area. A total of 157 malignant melanomas were diagnosed (60% from females and 40% from males) over the s...

state estimation is the foundation of any control and decision making in power networks. the first requirement for a secure network is a precise and safe state estimator in order to make decisions based on accurate knowledge of the network status. this paper introduces a new estimator which is able to detect bad data with few calculations without need for repetitions and estimation residual cal...