The Phosphacylium Ion: Evidence for its Existence as an Intermediate in Reactions of Organophosphates

Prior to this work, no strong evidence existed which unequivocably proved the existence of phosphacylium ions as intermediates in reactions of this type. It is the object of this study to look into nucleophilic substitution at phosphorus, and the intermediates of these possible dissociative type reactions

AN ANALYSIS OF A UNITED STATES-CANADA-MEXICO FREE TRADE AGREEMENT

This is one of two papers commissioned by the International Agricultural Trade Research Consortium on various aspects related to the agricultural sector of a prospective North American Free Trade Agreement. The companion paper to this one has been prepared by a working group chaired by Richard Barichello, University of British Columbia. To minimize duplication with the Barichello paper this paper has given greater attention to the role of Mexico, currency exchange rates, and explicit modeling of the trade relationship.International Relations/Trade,

An Algorithmic View on OVSF Code Assignment

Orthogonal Variable Spreading Factor (OVSF) codes are used in UMTS to share the radio spectrum among several connections of possibly different bandwidth requirements. The combinatorial core of the OVSF code assignment problem is to assign some nodes of a complete binary tree of height h (the code tree) to n simultaneous connections, such that no two assigned nodes (codes) are on the same root-to-leaf path. A connection that uses a 2-d fraction of the total bandwidth requires some code at depth d in the tree, but this code assignment is allowed to change over time. Requests for connections that would exceed the total available bandwidth are rejected. We consider the one-step code assignment problem: Given an assignment, move the minimum number of codes to serve a new request. Minn and Siu propose the so-called DCA algorithm to solve the problem optimally. In contrast, we show that DCA does not always return an optimal solution, and that the problem is NP-hard. We give an exact nO(h)-time algorithm, and a polynomial-time greedy algorithm that achieves approximation ratio Θ(h). A more practically relevant version is the online code assignment problem, where future requests are not known in advance. Our objective is to minimize the overall number of code reassignments. We present a Θ(h)-competitive online algorithm, and show that no deterministic online algorithm can achieve a competitive ratio better than 1.5. We show that the greedy strategy (minimizing the number of reassignments in every step) is not better than Ω(h) competitive. We give a 2-resource augmented online algorithm that achieves an amortized constant number of (re-)assignments. Finally, we show that the problem is fixed-parameter tractabl

Directing Intrinsic Chirality in Gold Nanoclusters: Preferential Formation of Stable Enantiopure Clusters in High Yield and Experimentally Unveiling the “Super” Chirality of Au144_{144}

Chiral gold nanoclusters offer significant potential for exploring chirality at a fundamental level and for exploiting their applications in sensing and catalysis. However, their widespread use is impeded by low yields in synthesis, tedious separation procedures of their enantiomeric forms, and limited thermal stability. In this study, we investigated the direct synthesis of enantiopure chiral nanoclusters using the chiral ligand 2-MeBuSH in the fabrication of Au$_{25}$, Au$_{38}$, and Au$_{144}$ nanoclusters. Notably, this approach leads to the unexpected formation of intrinsically chiral clusters with high yields for chiral Au$_{38}$ and Au$_{144}$ nanoclusters. Experimental evaluation of chiral activity by circular dichroism (CD) spectroscopy corroborates previous theoretical calculations, highlighting the stronger CD signal exhibited by Au$_{144}$ compared to Au$_{38}$ or Au$_{25}$. Furthermore, the formation of a single enantiomeric form is experimentally confirmed by comparing it with intrinsically chiral Au$_{38}$(2-PET)$_{24}$ (2-PET: 2-phenylethanethiol) and is supported theoretically for both Au$_{38}$ and Au$_{144}$. Moreover, the prepared chiral clusters show stability against diastereoisomerization, up to temperatures of 80°C. Thus, our findings not only demonstrate the selective preparation of enantiopure, intrinsically chiral, and highly stable thiolate-protected Au nanoclusters through careful ligand design but also support the predicted “super” chirality in the Au$_{144}$ cluster, encompassing hierarchical chirality in ligands, staple configuration, and core structure

Hinduismo e cristianesimo in dialogo

Il volume presenta in modo sintetico non solo la ricchezza che la tradizione religiosa hindú racchiude in sé, ma anche le principali prospettive su cui si sta sviluppando il dialogo hindū-cristiano.- Indice #9-Introduzione, Andrea Pacini #13- Hinduismo: elementi fondamentali caratterizzanti la tradizione hindū, Stefano Piano #19- Dio nelle tradizioni religiose hindū, Francis X. D’Sa #39- L’uomo e la salvezza nella tradizione hindū, Mario Piantelli #59- Le pratiche religiose nello hinduismo, Kala Acharya #81- Hinduismo, modernità e politica nell’India contemporanea, Urvashi Butalia #109- Hinduismo e religioni universali. Relazioni storiche e prospettive attuali di dialogo, Anantanand Rambachan #121- Le visioni hindū di Cristo, Anand Amaladass S. J. #139- Un volto indiano per Gesù Cristo, Jacques Dupuis #165- Possibilità molteplici di dialogo fra cristiani e hindū, Thomas Matus #193- Bibliografia generale #20

Анализ технологии предварительной подготовки нефти на месторождении "Н" (Красноярский край)

Объектом исследования является технология предварительной подготовки нефти на "Н" нефтегазоконденсатном месторождении. Целью выпускной квалификационной работы является анализ технологии предварительной подготовки нефти и подбор аппарата для отделения воды. В процессе выполнения выпускной квалификационной работы были изучены причины образования нефтяной эмульсии и способы ее разрушения; рассмотрены наиболее распространение устройства для отделения воды. Собраны данные по характеристике месторождения, составам пластовой нефти, газа и воды, технологии предварительной подготовки обводненной нефти.The object of the study is the technology of preliminary oil treatment at the" N " oil and gas condensate field. The purpose of the final qualification work is to analyze the technology of preliminary preparation of oil and the selection of a device for separating water. In the course of the final qualification work, the reasons for the formation of an oil emulsion and the methods of its destruction were studied; the most common devices for separating water were considered. Data on the characteristics of the field, the composition of reservoir oil, gas and water, and the technology of preliminary preparation of watered oil are collected

The contribution of macroalgae-associated fishes to small-scale tropical reef fisheries

Macroalgae-dominated reefs are a prominent habitat in tropical seascapes that support a diversity of fishes, including fishery target species. To what extent, then, do macroalgal habitats contribute to small-scale tropical reef fisheries? To address this question we: (1) Quantified the macroalgae-associated fish component in catches from 133 small-scale fisheries, (2) Compared life-history traits relevant to fishing (e.g. growth, longevity) in macroalgal and coral-associated fishes, (3) Examined how macroalgae-associated species can influence catch diversity, trophic level and vulnerability and (4) Explored how tropical fisheries change with the expansion of macroalgal habitats using a case study of fishery-independent data for Seychelles. Fish that utilised macroalgal habitats comprise 24% of the catch, but very few fished species relied entirely on macroalgal or coral habitats post-settlement. Macroalgal and coral-associated fishes had similar life-history traits, although vulnerability to fishing declined with increasing contribution of macroalgae association to the catch, whilst mean trophic level and diversity peaked when macroalgal-associated fish accounted for 20%-30% of catches. The Seychelles case study revealed similar total fish biomass on macroalgal and coral reefs, although the biomass of primary target species increased as macroalgae cover expanded. Our findings reinforce that multiple habitat types are needed to support tropical fishery stability and sustainability. Whilst coral habitats have been the focus of tropical fisheries management, we show the potential for macroalgae-associated fish to support catch size and diversity in ways that reduce vulnerability to overfishing. This is pertinent to seascapes where repeated disturbances are facilitating the replacement of coral reef with macroalgal habitats

Essential Role of Neuron-Enriched Diacylglycerol Kinase (DGK), DGKβ in Neurite Spine Formation, Contributing to Cognitive Function

BACKGROUND: Diacylglycerol (DG) kinase (DGK) phosphorylates DG to produce phosphatidic acid (PA). Of the 10 subtypes of mammalian DGKs, DGKbeta is a membrane-localized subtype and abundantly expressed in the cerebral cortex, hippocampus, and caudate-putamen. However, its physiological roles in neurons and higher brain function have not been elucidated. METHODOLOGY/PRINCIPAL FINDINGS: We, therefore, developed DGKbeta KO mice using the Sleeping Beauty transposon system, and found that its long-term potentiation in the hippocampal CA1 region was reduced, causing impairment of cognitive functions including spatial and long-term memories in Y-maze and Morris water-maze tests. The primary cultured hippocampal neurons from KO mice had less branches and spines compared to the wild type. This morphological impairment was rescued by overexpression of DGKbeta. In addition, overexpression of DGKbeta in SH-SY5Y cells or primary cultured mouse hippocampal neurons resulted in branch- and spine-formation, while a splice variant form of DGKbeta, which has kinase activity but loses membrane localization, did not induce branches and spines. In the cells overexpressing DGKbeta but not the splice variant form, DGK product, PA, was increased and the substrate, DG, was decreased on the plasma membrane. Importantly, lower spine density and abnormality of PA and DG contents in the CA1 region of the KO mice were confirmed. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that membrane-localized DGKbeta regulates spine formation by regulation of lipids, contributing to the maintenance of neural networks in synaptic transmission of cognitive processes including memory

Detection and verification of malting quality QTLs using wild barley introgression lines

A malting quality quantitative trait locus (QTL) study was conducted using a set of 39 wild barley introgression lines (hereafter abbreviated with S42ILs). Each S42IL harbors a single marker-defined chromosomal segment from the wild barley accession ‘ISR 42-8’ (Hordeum vulgare ssp. spontaneum) within the genetic background of the elite spring barley cultivar ‘Scarlett’ (Hordeum vulgare ssp. vulgare). The aim of the study was (1) to verify genetic effects previously identified in the advanced backcross population S42, (2) to detect new QTLs, and (3) to identify S42ILs exhibiting multiple QTL effects. For this, grain samples from field tests in three different environments were subjected to micro malting. Subsequently, a line × phenotype association study was performed with the S42ILs in order to localize putative QTL effects. A QTL was accepted if the trait value of a particular S42IL was significantly (P < 0.05) different from the recurrent parent as a control, either across all tested environments or in a particular environment. For eight malting quality traits, altogether 40 QTLs were localized, among which 35 QTLs (87.5%) were stable across all environments. Six QTLs (15.0%) revealed a trait improving wild barley effect. Out of 36 QTLs detected in a previous advanced backcross QTL study with the parent BC2DH population S42, 18 QTLs (50.0%) could be verified with the S42IL set. For the quality parameters α-amylase activity and Hartong 45°C, all QTLs assessed in population S42 were verified by S42ILs. In addition, eight new QTL effects and 17 QTLs affecting two newly investigated traits were localized. Two QTL clusters harboring simultaneous effects on eight and six traits, respectively, were mapped to chromosomes 1H and 4H. In future, fine-mapping of these QTL regions will be conducted in order to shed further light on the genetic basis of the most interesting QTLs