Equilibrium twist angles and rotational barriers for the three isomeric phenylpyrroles were calculated by means of MNDO and AMI. In each case MNDO incorrectly predicts the perpendicular conformation as the most stable one. In agreement with experimental evidence AMI predicts only slight deviations from planarity and very low 0°-barriers (1-phenylpyrrole: 0 = 28°, E = F6 kJ mol"; 2-phenylpyrrole...

efficient cyclization upon irradiation in acetonitrile to produce the spirocyclic enol ethers or esters 56-59. The ease of formation of the salts coupled with the exceptional chemical efficiencies and structural outcomes of these cyclizations indicates that this methodology will have synthetic utility. The results also demonstrate the importance of trialkylsilyl substituents in electrontransfer...

We consider the empirical risk minimization problem for linear supervised learning, with regularization by structured sparsity-inducing norms. These are defined as sums of Euclidean norms on certain subsets of variables, extending the usual l1-norm and the group l1-norm by allowing the subsets to overlap. This leads to a specific set of allowed nonzero patterns for the solutions of such problem...

In past few years, several techniques have been proposed for training of linear Support Vector Machine (SVM) in limited-memory setting, where a dual blockcoordinate descent (dual-BCD) method was used to balance cost spent on I/O and computation. In this paper, we consider the more general setting of regularized Empirical Risk Minimization (ERM) when data cannot fit into memory. In particular, w...

Satellite-derived vegetation phenophases are frequently used to study the response of ecosystems to climate change. However, limited studies have identified the common phenological variability across different climate and vegetation zones. Using NOAA/Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI) dataset, we estimated start of growing season (SOS)...

We consider the problem of minimizing the sum of two convex functions: one is smooth and given by a gradient oracle, and the other is separable over blocks of coordinates and has a simple known structure over each block. We develop an accelerated randomized proximal coordinate gradient (APCG) method for minimizing such convex composite functions. For strongly convex functions, our method achiev...

We describe methods for predicting cytochrome P450 (CYP) metabolism incorporating both pathway-specific reactivity and isoform-specific accessibility considerations. Semiempirical quantum mechanical (QM) simulations, parametrized using experimental data and ab initio calculations, estimate the reactivity of each potential site of metabolism (SOM) in the context of the whole molecule. Ligand-bas...

T h e e l e c t r o n i c s p e c t r a o f a s e r i e s o f s u b s t i t u t e d 4 h y d r o x y p y r i d o n e s a r e c a l c u l a t e d b y t h e C N D O / C I m e t h o d . B e s t a g r e e m e n t b e t w e e n o b s e r v e d a n d c a l c u l a t e d t r a n s i t i o n e n e r g i e s i s o b t a i n e d w h e n t h e g e o m e t r y o f t h e p y r i d o n e f o r m i s a s s u m...

The results of a theoretical study on the interaction of o-tetrafluorophenylene mercury with ethylene and acetylene are reported. The AM1 molecular orbital semiempirical method is applied through a complete optimization procedure without any restrictions to find the optimal equilibrium geometries. The comparative capabilities of ethylene and acetylene molecules to form stable complexes with o-t...

Dimensionality reduction is a popular approach for dealing with high dimensional data that leads to substantial computational savings. Random projections are a simple and effective method for universal dimensionality reduction with rigorous theoretical guarantees. In this paper, we theoretically study the problem of differentially private empirical risk minimization in the projected subspace (c...