Social anxiety symptoms in young children:Investigating the interplay of theory of mind and expressions of shyness

Children’s early onset of social anxiety may be associated with their social understanding, and their ability to express emotions adaptively. We examined whether social anxiety in 48-month-old children (N = 110; 54 boys) was related to: a) a lower level of theory of mind (ToM); b) a lower proclivity to express shyness in a positive way (adaptive); and c) a higher tendency to express shyness in a negative way (non-adaptive). In addition, we investigated to what extent children’s level of social anxiety was predicted by the interaction between ToM and expressions of shyness. Children’s positive and negative expressions of shyness were observed during a performance task. ToM was measured with a validated battery, and social anxiety was assessed using both parents’ reports on questionnaires. Socially anxious children had a lower level of ToM, and displayed more negative and less positive shy expressions. However, children with a lower level of ToM who expressed more positive shyness were less socially anxious. Additional results show that children who displayed shyness only in a negative manner were more socially anxious than children who expressed shyness only in a positive way and children who did not display any shyness. Moreover, children who displayed both positive and negative expressions of shyness were more socially anxious than children who displayed shyness only in a positive way. These findings highlight the importance of ToM development and socio-emotional strategies, and their interaction, on the early development of social anxiety

Quantum Algorithms for the k-xor Problem

International audienceThe k-xor (or generalized birthday) problem is a widely studied question with many applications in cryptography. It aims at finding k elements of n bits, drawn at random, such that the xor of all of them is 0. The algorithms proposed by Wagner more than fifteen years ago remain the best known classical algorithms for solving them, when disregarding logarithmic factors. In this paper we study these problems in the quantum setting, when considering that the elements are created by querying a random function (or k random functions) H : {0, 1} n → {0, 1} n. We consider two scenarios: in one we are able to use a limited amount of quantum memory (i.e. a number O(n) of qubits, the same as the one needed by Grover's search algorithm), and in the other we consider that the algorithm can use an exponential amount of qubits. Our newly proposed algorithms are of general interest. In both settings, they provide the best known quantum time complexities. In particular, we are able to considerately improve the 3-xor algorithm: with limited qubits, we reach a complexity considerably better than what is currently possible for quantum collision search. Furthermore, when having access to exponential amounts of quantum memory, we can take this complexity below O(2 n/3), the well-known lower bound of quantum collision search, clearly improving the best known quantum time complexity also in this setting. We illustrate the importance of these results with some cryptographic applications

Gas chromatographic retention indices for the N-methyl-N-substituted benzamides on capillary columns

Gas chromatographic retention indices (1) for series of 20 synthesized N-methyl-N-substituted benzamides on DB-I, DB-5 and DB-WAX capillary columns isothermal at 170, 190 and 210 degreesC, and using temperature programmed gas chromatography (TPGC) have been determined within standard deviation of 0.6 i.u. The isothermal data obtained on these columns and TPGC data are compared and a comparison of the retention indices, DeltaI and dI/dT values presented as linear regression equations with correlation coefficient greater than 0.9970 within standard deviation of 0.6 i.u. The best resolution of the structural isomers is obtained using DB-1 capillary column

Conformations of unsymmetrical N-t-butyl-N-substituted 2-phenylacetamides

Various N-t-butyl-N-substituted 2-phenylacetamides, PhCH2CON(t-Bu)R, wherein R is methyl, ethyl, n-propyl, n-butyl, i-propyl, phenyl and cyclohexyl, were synthesized, Depending on the kind of substituent on the nitrogen atom, some of the examined amides exist in different conformational forms, H-1 NMR and C-13 NMR spectra of these unsymmetrically N,N-disubstituted amides have been studied and peaks have been assigned in each case to the two possible conformational isomers, arising from the lack of free rotation about the C(O)-N bond, The relative distribution of cis and trans isomers has been established by means of different coupling constants and the NOE difference technique, Information about fragmentation routes, and the effect of overall and partial structures were obtained by the study of the metastable ions, The results are in accordance with our previous investigations of the structures of N,N-disubstituted 2-phenylacetamides

A New Approach to the Understanding of the Mechanism of Lead Electrodeposition

The most important applications of lead include the production of high purity active materials for acid battery, for semiconductors, and for the fabrication of electrochromic devices. In the form of powder, lead is widely used in industries of gas and oil exploration, radiological medical protective clothing, as an industrial X-ray shield, golf club manufacture, and antifriction products. The electrodeposition technique is a very suitable way to obtain lead in the form suitable for the application in the above-mentioned technologies. For example, the advantage of use of electrodeposition technique in the production of lead in the powder form lies in the fact that lead powder is produced at low overpotentials and hence with small spent of energy. The open porous structures of lead with the extremely high surface area (the honeycomb-like ones), which are ideally situated for electrodes in electrochemical devices such as fuel cells, batteries, and sensors, are also possible to get by the electrodeposition techniques

Synthesis and FTIR spectroscopic study of some N-monosubstituted propanamides

In the present work we investigated the conformations of some N-mono-substituted propanamides of general formula CH3CH2CONHR, wherein R is chosen from n-(C-1-C-9)alkyl, cyclo(C-3-C-6)alkyl, some branched (C-3-C-6)alkyl or phenyl. The amides were synthesised by the well known Schotten-Baumann reaction-acylation of the corresponding amines with propionyl chloride. On the basis of FTIR data for diluted solutions (concentrations below 10(-3) mol dm(-3)) of N-mono-substituted propanamides in carbon tetrachloride, chloroform, dichloromethane, or a 1:1.5 mixture of benzene and carbon tetrachloride the exact position of the N-H stretching band was established. For spectroscopic data the different conformational isomers were assigned and its structures unequivocally proven. These results are in good accordance with H-1 NMR and MS data