This manuscript describes the role of non-classical hydrogen bonds (NCHBs), specifically C–H···O interactions, in modern synthetic organic transformations. Our goal is to point out the seminal examples where C–H···O interactions have been invoked as a key stereocontrolling element and to provide predictive value in recognizing future and/or potential C–H···O interactions...
Co-opetition, or simultaneous competition and cooperation, in the supply chain management literature has been treated as a dyadic relational phenomenon where the buyer's strategy is considered to be the primary driver. In this paper, we move beyond the dyadic view and propose a theory of co-opetition in supply networks. We...
Excessive fiscal spending is commonly cited as a root of the current European debt
crisis. This paper suggests, like others, that the rise of competitiveness imbalances contributing
to national imbalances in total borrowing are a better explanation for systemic differences
towards EMU countries’ exposure to market speculation. We identify one...
The quality of lumber and veneer recovered from logs of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is directly influenced by the maximum limb size attained on the crop tree. Because limb sizes are influenced by standdensity regimes, a need has arisen for quantitative tools that link a wide array of silvicultural...
OBJECTIVE: In this study, we examined how effectively
people can monitor new stimuli on a peripheral display
while carrying out judgments on an adjacent central display.
BACKGROUND: Improved situation awareness is critical
for improved operator performance in aviation and many
other domains. Given the limited extent of foveal processing,
acquiring...
Active mountain building associated with the accretion of the Yakutat microplate (YT) in southern Alaska is characterized through the combination of a new balanced cross section and new low-temperature cooling ages. This analysis constrains the amount and timing of shortening, the spatial and temporal trends of exhumation, and the interplay...
Conspectus:
The flexibility, complexity, and size of contemporary organocatalytic transformations pose interesting and powerful opportunities to computational and experimental chemists alike. In this Account, we disclose our recent computational investigations of three branches of organocatalysis in which nonbonding interactions, such as C–H···O/N interactions, play a crucial role in the organization...
This study describes the combined experimental and computational elucidation of the mechanism and
origins of stereoselectivities in the NHC-catalyzed dynamic kinetic resolution (DKR) of α-substituted-β-ketoesters. Density functional theory computations reveal that the NHC-catalyzed DKR proceeds by two
mechanisms, depending on the stereochemistry around the forming bond: 1) a concerted, asynchronous...
The regiodivergent O- to C- or N-carboxyl transfer of pyrazolyl carbonates is described, with DMAP giving preferential N-carboxylation and triazolinylidenes promoting selective C-carboxylation (both with up to >99 : 1 regioselectivity). An enantioselective O- to C-carboxyl variant using NHC catalysis is demonstrated (up to 92% ee), while mechanistic and DFT studies outline...
Mild mutations in BRCA2 (FANCD1) cause Fanconi anemia (FA) when homozygous, while severe mutations cause common cancers including breast, ovarian, and prostate cancers when heterozygous. Here we report a zebrafish brca2 insertional mutant that shares phenotypes with human patients and identifies a novel brca2 function in oogenesis. Experiments showed that...
Objective: To translate a behavioral weight loss intervention for mid-life, low-income women in real world settings.
Design and Methods: In this pragmatic clinical trial, we randomly selected six North Carolina county health departments and trained their current staff to deliver a 16-session evidence-based behavioral weight loss intervention (special intervention, SI)....
Whereas capture experiments typically repeat a single task many times, real world cognition is
characterized by frequent switching. Lien, Ruthruff, and Johnston (2010) reported that the
attentional control system can rapidly and fully switch between different search settings (e.g., red
to green), with no carryover and no inter-trial priming. The...
We demonstrate time-resolved terahertz transmission ellipsometry of vertically aligned multi-walled carbon nanotubes. The angle-resolved transmission measurements reveal anisotropic characteristics of the terahertz electrodynamics in multi-walled carbon nanotubes. The anisotropy is, however, unexpectedly weak: the ratio of the tube-axis conductivity to the transverse conductivity, sigma[subscript z]/sigma[subscript xy] [similar or equal to]...
Background: In the leuphotrochozoan parasitic platyhelminth Schistosoma mansoni, male individuals are homogametic (ZZ) whereas females are heterogametic (ZW). To elucidate the mechanisms that led to the emergence of sex chromosomes, we compared the genomic sequence and the chromatin structure of male and female individuals. As for many eukaryotes, the lower...
The rhenium-osmium isotopic system has the potential to track the maturation of arc crust at lower crustal levels because the ¹⁸⁷Os/¹⁸⁸Os in magmas is sensitive to the age and composition of crust with which they interact. We here present Re and Os isotopic data for a suite of samples from...
The ability of ruminal microbes to degrade the explosive compound hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in ovine whole rumen fluid (WRF) and as 24 bacterial isolates was examined under anaerobic conditions. Compound degradation was monitored by high performance liquid chromatography (HPLC) analysis, followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) identification of metabolites....
Restricted rotations of chemical bonds can lead to the presence of persistent conformational chirality in molecules 10 lacking stereocenters. We report the development of first-ofa- kind predictive rules that enable identification of conformational chirality and prediction of racemization barriers in the diarylether heptanoid (DAEH) natural products that do not possess...
The interaction of the dominant semidiurnal M₂ internal tide with the large-scale subtidal flow is examined
in an ocean model by propagating the tide through an ensemble of background fields in a domain centered on
the Hawaiian Ridge. The background fields are taken from the Simple Ocean Data Assimilation (SODA)...
Many studies have shown that ground beetles feed on different agricultural pests, but little is known about their species communities from US cropping systems. We assessed the biological control potential of the most common carabid beetle species in Oregon annual ryegrass grown for seed by investigating spatial and temporal overlap...