Characterization of Vegetables by Stable Isotopic and Elemental Signatures

ABSTRACT

109 Romanian parsley, celery and parsnip root, cucumber, vegetable marrow, onion, and pepper samples were characterized by their stable isotope ratios and elemental concentrations in comparison to imported varieties. Organic and conventional agriculture practices were also compared as well as a differentiation between eggplant and peppers grown in greenhouses and those in the field. δ²H values were between ?70.8 and 5.6‰, while the δ¹⁸O values were between ?9.0 and 4.1‰. The δ¹⁵N values for white onions were from 2.8 to 11.1‰. For Romanian organic onions, the carbon isotopic values were lower (?29.2 to ?28.2‰) compared to conventional onions from other countries (?27.8‰ to ?23.8%). Linear discriminant analysis was used to characterize agricultural practices and the geographic origin of the vegetables.     

Binary relations and reduced hypergroups

Different partial hypergroupoids are associated with binary relations defined on a set H. In this paper we find sufficient and necessary conditions for these hypergroupoids in order to be reduced hypergroups. Given two binary relations ρ and σ on H we investigate when the hypergroups associated with the relations ρ∩σ, ρ∪σ and ρσ are reduced. We also determine when the cartesian product of two hypergroupoids associated with a binary relation is a reduced hypergroup.     

Integrating Lys-N proteolysis and N-terminal guanidination for improved fragmentation and relative quantification of singly-charged ions

Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA The study of isolated protein complexes has greatly benefited from recent advances in mass spectrometry instrumentation and quantitative, isotope labeling techniques. The comprehensive characterization of protein complex components and quantification of their relative abundance relies heavily upon maximizing protein and peptide sequence information obtained from MS and tandem MS studies. Recent work has shown that using a metalloendopeptidase, Lys-N, for proteomic analysis of biological protein mixtures produces complementary protein sequence information compared with trypsin digestion alone. Here, we have investigated the suitability of Lys-N proteolysis for use with MALDI mass spectrometry to characterize the yeast Arp2 complex and E. coli PAP I protein interactions. Although Lys-N digestion resulted in an average decrease in protein sequence coverage of ∼30% compared with trypsin digestion, CID analysis of singly-charged Lys-N peptides yielded a more extensive b-ions series compared with complementary tryptic peptides. Taking advantage of this improved fragmentation pattern, we utilized differential ¹⁵N/¹⁴N guanidination of Lys-N peptides and MALDI-MS/MS analysis to relatively quantify the changes in PAP I associations due to deletion of sprE, previously shown to regulate PAP I-dependent polyadenylation. Overall, this Lys-N/guanidination integrative approach is applicable for functional proteomic studies utilizing MALDI mass spectrometry analysis, as it provides an effective and economical mean for relative quantification of proteins in conjunction with increased sensitivity of detection and fragmentation efficiency.     

Links Between HX-Groups and Hypergroups

The concept of an HX-group is an upgrade of the concept of a group,in which a new operation is defined on the family of non-empty subsets of a group.If this new support set together with the new operation is a group,then we call it an HX-group.On the other hand,a hyperoperation is a mapping having the same codomain as the operation of an HX-group,i.e.,the family of non-empty subsets of the initial set,but a different domain-the set itself.This could be (and was indeed) a source of confusion,which is clarified in this paper.Moreover,HX-groups naturally lead to constructions of hypergroups.The links between these two algebraic concepts are presented,with the aim of reviving the old notion of an HX-group in the current research on algebraic hyperstructures.One of such existing links and one newly established link are also discussed.     

Viscoelastic and dielectric behaviour of thin films made from siloxane-containing poly(oxadiazole-imide)s

Siloxane-containing poly(oxadiazole-imide)s were prepared by polycondensation reaction of two aromatic diamino-oxadiazoles with a dianhydride containing tetramethylsiloxane moiety. Free-standing flexible films having good mechanical properties were made therefrom. The polyimides exhibited high thermal stability with initial decomposition temperature being above 440 °C and glass transition in the range of 165-183 °C. The dielectric constant values, measured at room temperature and in the frequency domain of 1 Hz-1 MHz, are in the range of 2.69-2.90, being significantly lower in comparison with that of Kapton HN® film, whose dielectric constant values ranged from 3.13 to 3.24. The dielectric loss values are low, in the same range with those of Kapton HN®. The dielectric spectroscopy data corroborated with the dynamo-mechanical analysis ones showed distinct sub-glass transitions for these polymers: γ relaxations with activation energies of 44 and 45 kJ/mol, and a β relaxation with an activation energy of 107 kJ/mol. The dielectric properties are discussed in comparison with those of Kapton HN® film measured under the same conditions.     

Lower and upper fuzzy topological subhypergroups

This paper provides a new connection between algebraic hyperstructures and fuzzy sets. More specifically, using both properties of fuzzy topological spaces and those of fuzzy subhypergroups, we define the notions of lower (upper) fuzzy topological subhypergroups of a hypergroup endowed with a fuzzy topology. Some results concerning the image and the inverse image of a lower (upper) topological subhypergroup under a very good homomorphism of hypergroups (endowed with fuzzy topologies) are pointed out.     

On Fuzzy Preordered Structures and （Fuzzy） Hyperstructures

This article presents a connection between fuzzy preordered structures and hyperstructures. Firstly, we introduce the notion of fuzzy preordered semigroup and then, we construct a semihypergroup associated with it, giving some properties of the associated hyperstructure. Secondly, we define the notion of fuzzy preordered ring in order to construct a fuzzy hyperring.