Classification systems based on rough sets under the belief function framework

In this paper, we present two classification approaches based on Rough Sets (RS) that are able to learn decision rules from uncertain data. We assume that the uncertainty exists only in the decision attribute values of the Decision Table (DT) and is represented by the belief functions. The first technique, named Belief Rough Set Classifier (BRSC), is based only on the basic concepts of the Rough Sets (RS). The second, called Belief Rough Set Classifier, is more sophisticated. It is based on Generalization Distribution Table (BRSC-GDT), which is a hybridization of the Generalization Distribution Table and the Rough Sets (GDT-RS). The two classifiers aim at simplifying the Uncertain Decision Table (UDT) in order to generate significant decision rules for classification process. Furthermore, to improve the time complexity of the construction procedure of the two classifiers, we apply a heuristic method of attribute selection based on rough sets. To evaluate the performance of each classification approach, we carry experiments on a number of standard real-world databases by artificially introducing uncertainty in the decision attribute values. In addition, we test our classifiers on a naturally uncertain web usage database. We compare our belief rough set classifiers with traditional classification methods only for the certain case. Besides, we compare the results relative to the uncertain case with those given by another similar classifier, called the Belief Decision Tree (BDT), which also deals with uncertain decision attribute values.     

D3R Grand Challenge 2: blind prediction of protein–ligand poses,affinity rankings,and relative binding free energies

The Drug Design Data Resource (D3R) ran Grand Challenge 2 (GC2) from September 2016 through February 2017. This challenge was based on a dataset of structures and affinities for the nuclear receptor farnesoid X receptor (FXR), contributed by F. Hoffmann-La Roche. The dataset contained 102 IC50 values, spanning six orders of magnitude, and 36 high-resolution co-crystal structures with representatives of four major ligand classes. Strong global participation was evident, with 49 participants submitting 262 prediction submission packages in total. Procedurally, GC2 mimicked Grand Challenge 2015 (GC2015), with a Stage 1 subchallenge testing ligand pose prediction methods and ranking and scoring methods, and a Stage 2 subchallenge testing only ligand ranking and scoring methods after the release of all blinded co-crystal structures. Two smaller curated sets of 18 and 15 ligands were developed to test alchemical free energy methods. This overview summarizes all aspects of GC2, including the dataset details, challenge procedures, and participant results. We also consider implications for progress in the field, while highlighting methodological areas that merit continued development. Similar to GC2015, the outcome of GC2 underscores the pressing need for methods development in pose prediction, particularly for ligand scaffolds not currently represented in the Protein Data Bank (http://www.pdb.org), and in affinity ranking and scoring of bound ligands.     

Synthesis and Reactions of Some Novel Triazolo‐, Azolo‐, Tetrazolo‐Pyridopyrimidine and Their Nucleoside Derivatives

Pyridopyrimidine reacted with aromatic aldehydes afforded the arylhydrazone 2a,b which could be cyclized into the pyrido[2,3‐d][1,2,4]triazolo[4,3‐a]pyrimidine 3a,b , with formic acid, and carbon disulphide to give pyrido[2,3‐d][1,2,4]traizolo[4,3‐a]pyrimidine 4, 5. Reaction of 1 with nitrous acid afforded tetrazolo[1,5‐a]pyrido[2,3‐d]pyrimidine 6 , which was reduced by zinc dust to give 2‐amino‐pyrido‐[2,3‐d]pyrimidine 7. Finally the reaction of 2‐hydrazino 1 with D‐xylose or D‐glucose afforded the acyclic N‐nucleoside 8, 11 which were converted into tetra/penta O‐acetate acyclic C‐nucleoside 9, 12 in acetic anhydride/pyridine. De‐acetylation of compounds 9, 12 afforded C‐nucleosides 10, 13.     

Using Electron Induced Dissociation (EID) on an LC Time-Scale to Characterize a Mixture of Analogous Small Organic Molecules

LC ESI FTICR MS of a sample of cediranib identified this pharmaceutical target molecule plus an additional 10 compounds of interest, all of which were less than 10% total ion current (TIC) peak intensity relative to cediranib. LC FTICR tandem mass spectrometry using electron induced dissociation (EID) has been achieved and has proven to be the best way to generate useful product ion information for all of these singly protonated molecules. Cediranib [M + H]⁺ fragmented by EID to give 29 product ions whereas QTOF-CID generated only one very intense product ion, and linear ion trap-CID, which generated 10 product ions, but all with poor S/N. Twenty-six of the EID product ions were unique to this fragmentation technique alone. By considering the complementary LC-EID and LC-CID data together, all 10 unknown compounds were structurally characterized and proven to be analogous to cediranib. Of particular importance, EID produced unique product ion information for one of the low level cediranib analogues that enabled full characterization of the molecule such that the presence of an extra propylpyrrolidine group was discovered and proven to be located on the pyrrolidine ring of cediranib, solving an analytical problem that could not be solved by collision induced dissociation (CID). Thus, it has been demonstrated that EID is in harmony with the chromatography duty-cycle and the dynamic concentration range of synthetic compounds containing trace impurities, providing crucial analytical information that cannot be obtained by more traditional methodologies.     

Heterocyclization of acylthiosemicarbazides

The review summarizes published data on the behavior and reactions of acylthiosemicarbazides and their derivatives, which lead to the formation of heterocyclic systems, including methods of preparation in addition to synthesis of pyrrole, thiazole, thiadiazole, thiadiazolidine, and triazole derivatives as well as fused heterocyclic compounds. J. Heterocyclic Chem., (2012).     

On Odd Perturbations of Free Fermion Fields

We study the scattering theory of fermion systems subject to a smooth local perturbation with a non-vanishing odd part. We introduce a modified free fermion fields which have an appropriate commutation relations with the free Fock fermion fields. We construct the wave operators using the modified field and prove asymptotic completeness. Our work extends former results on Hilbert space asymptotic completeness.     

Synthesis,characterization, structures,and DFT study of zinc(II) complexes with tributylphosphine chalcogenides

Four new zinc(II) complexes of the type [ZnCl₂(n-Bu₃PE)₂] (E=O (1), S (2), Se (3), or Te (4)) have been synthesized from zinc(II) chloride and the ligands n-Bu₃PE giving yields of 56–88%. The adducts were characterized by multinuclear (³¹P, ¹³C, and ⁷⁷Se) NMR, conductivity, IR spectroscopy and by X-ray analyses. Zinc complexes 1–4 are compriseS of two ligands coordinated to the metal center in a distorted tetrahedral arrangement. The P=E bond lengths of 1.497(7) (E=O), 2.000(4) (E=S), and 2.178(2) Å (E=Se) in these complexes are slightly elongated compared to those in the free ligand. In addition, a DFT/B3LYP theoretical study on the geometry optimization of the title ligands and their zinc complexes has been carried out in order to support and complement the experimental data and to further investigate the nature of the chalcogenide-metal interaction. The results show good agreement between the experimental and theoretical data.     

Reaction of 1‐acylthiosemicarbazides with ethenetetracarbonitrile

1‐Acylthiosemicarbazides 9a‐d reacted with ethenetetracarbonitrile (TCNE, 2 ) in ethyl acetate with formation of N′‐(4‐amino‐5,6‐dicyano‐2H‐1,3‐thiazin‐2‐ylidene) substituted hydrazide 10a‐d , N′‐(5‐amino‐3,4‐dicyano‐2H‐pyrrol‐2‐ylidene)‐2‐substituted hydrazide 11a‐d and 2‐substituted imidazo[2,1‐b][1,3,4]‐oxadiazole‐5,6‐dicarbonitrile 12a‐d . Rationales for the conversions observed are presented.     

Kinetic properties of pancreatic and intestinal sPLA2 from chicken and mammals using the monomolecular film technique

The interfacial kinetic and binding data for the pancreatic and intestinal sPLA2 from bird and mammals show that these enzymes have dramatically different ability to bind and hydrolyse phospholipids. The main conclusions from our experimental data indicate that phosphatidylcholine monolayers (PC), in contrast to phosphatidylethanolamine (PE) and phosphatidylglycerol (PG), were resistant to the hydrolysis by human intestinal sPLA2. Conversely, chicken intestinal sPLA2 was found to be able to hydrolyse all the phospholipids tested, including PC. The experiments show also that the interfacial penetrating ability of chicken sPLA2 (from intestine and pancreas) was higher than their mammalian's orthologs. This observation is confirmed by the activity of pancreatic chicken PLA2 measured on PC film showing that the interfacial pressure window that permits sPLA2 activity was very large, between 5 and 20 dynes cm(-1), compared with the porcine pancreatic sPLA2-IB which was inactive at pressure above 15 dynes cm(-1). In trying to establish a structure-function relationship, we examined the surface electrostatic potentials of the various sPLA2 from chicken and mammals. We reported in this study that the binding, orientation and persistence of sPLA2 at the lipid-water interface is probably governed by the electrostatic and hydrophobic forces operative at this surface. These variations argue strongly that these enzymes are not isoforms and that they are expected to have functions other than the release of lipid mediators for the biosynthesis of the eicosanoids.     

On the Projections of the Mutual Multifractal Rényi Dimensions

In this paper, we compare the mutual multifractal Rényi dimensions to the mutual multifractal Hausdorff and pre-packing dimensions. We also provide a relationship between the mutual multifractal Rényi dimensions of orthogonal projections of a couple of measures $(\mu,\nu)$ in $\mathbb{R}^n$. As an application, we study the mutual multifractal analysis of the projections of measures.